Title:
SYSTEM AND METHOD FOR SAFING AND ARMING A BORE-LAUNCHED PROJECTILE
Kind Code:
A1


Abstract:
A safing and arming (SA) system and method for a bore-launched projectile is provided. The SA system includes an arming switch, including a detonator, movable from a first position to a second position. When the arming switch is in the first position, the detonator is separated from an explosive train of the projectile. When the arming switch is in the second position, the detonator is substantially aligned with the explosive train, allowing the projectile to be armed. Safing systems are provided for retaining the arming switch in the first (safe) position. Various embodiments also allow for release of the arming switch so as to allow the arming switch to be moved to the second (armed) position, wherein the release may be triggered by a selected acceleration force exerted on the projectile and/or a determination that the projectile has been launched from the launch bore.



Inventors:
Sigler, John William (La Mirada, CA, US)
Mandich, John Philip (Anaheim, CA, US)
Application Number:
11/534967
Publication Date:
03/27/2008
Filing Date:
09/25/2006
Assignee:
Chang Industry, Inc.
Primary Class:
International Classes:
F42C15/24
View Patent Images:
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Primary Examiner:
HAYES, BRET C
Attorney, Agent or Firm:
ALSTON & BIRD LLP (CHARLOTTE, NC, US)
Claims:
That which is claimed:

1. A safing and arming system adapted to be operably engaged with a projectile including an explosive train, the projectile being adapted to be launched from a launch bore, the system comprising: an arming switch configured to be movable from a first position to a second position, the arming switch being further configured to operably engage a detonator such that, when the arming switch is in the first position, the detonator operably engaged therewith is substantially out of alignment with the explosive train and such that, when the arming switch is in the second position, the detonator operably engaged therewith is substantially aligned with the explosive train such that the explosive train is capable of being armed; a first acceleration safety device configured to be capable of operably engaging the arming switch so as to normally retain the arming switch in the first position, the first acceleration safety device being further configured to disengage the arming switch so as to allow the arming switch to be moved to the second position, in response to an acceleration force having a selected magnitude and a selected duration, the acceleration force being imparted on the first acceleration safety device by an acceleration of the projectile with respect to the launch bore during a launch of the projectile; and a proximity safety device configured to be capable of operably engaging the arming switch so as to normally retain the arming switch in the first position, the proximity safety device being further configured to sense an inner wall defining the launch bore so as to allow the arming switch to be moved to the second position, such that the explosive train is capable of being armed, when the projectile is launched from the launch bore.

2. A safing and arming system according to claim 1, wherein the proximity safety device comprises: a first pin slidably disposed in a first pin, the first pin including a first end configured to contact the inner wall of the launch bore and a second end configured to engage the arming switch so as to normally retain the arming switch in the first position when the projectile is disposed within the launch bore; and a biasing element operably engaged with the first pin, and configured to bias the first pin towards the inner wall of the launch bore such that, when the projectile is launched from the launch bore, the first end of the first pin becomes unconstrained, and the second end of the first pin disengages the arming switch such that the arming switch is capable of being moved to the second position so that the explosive train is capable of being armed.

3. A safing and arming system according to claim 1, further comprising an actuator device operably engaged with the arming switch and configured to be capable of moving the arming switch from the first position to the second position in response to a signal.

4. A safing and arming system according to claim 3, wherein the proximity safety device further comprises a tab configured to normally cover an optical sensor in communication with the detonator, the tab being configured to uncover the optical sensor when the projectile is launched from the launch bore such that the optical sensor is capable of transmitting the signal to the actuator device so that the actuator device is capable of moving the arming switch from the first position to the second position at a selected time after the projectile is launched from the launch bore.

5. A safing and arming system according to claim 3, further comprising: a wiring assembly configured to short circuit the signal to prevent the signal from being transmitted to the actuator device; and a second acceleration safety device configured to be capable of disabling the wiring assembly in response to the acceleration force such that the signal is capable of being transmitted to the actuator device.

6. A safing and arming system according to claim 1, wherein the arming switch comprises a rotatable cylinder having a central axis and defining an arming channel extending radially outward from the central axis, the arming channel being configured to receive the detonator such that, as the rotatable cylinder is rotated from the first position to the second position, the detonator becomes substantially aligned with the explosive train so that the explosive train is capable of being armed.

7. A safing and arming system according to claim 1, wherein the first acceleration safety device comprises: a first setback weight slidably disposed in a first setback weight chamber; a second pin configured to be capable of operably engaging the arming switch so as to normally retain the arming switch in the first position; and a first linkage arm operably engaged between the first setback weight and the second pin such that, as the first setback weight slides within the first setback weight chamber in response to the acceleration force, the first linkage arm is configured to disengage the second pin from the arming switch so as to allow the arming switch to be moved to the second position.

8. A safing and arming device according to claim 7, wherein the first setback weight is configured to slide within the first setback weight chamber in response to the acceleration force having the selected magnitude and the selected duration.

9. A safing and arming system according to claim 5, wherein the second acceleration safety device comprises: a second setback weight slidably disposed in a second setback weight chamber; a cutting device slidably disposed in a cutting channel; and a second linkage arm operably engaged between the second setback weight and the cutting device such that, as the second setback weight slides within the second setback weight chamber in response to the acceleration force, the second linkage arm is configured to move the cutting device within the cutting channel such that the cutting device cuts at least one wire within the wiring assembly so that the signal is capable of being transmitted to the actuator device.

10. A safing and arming device according to claim 9, wherein the second setback weight is configured to slide within the second setback weight chamber in response to the acceleration force having the selected magnitude and the selected duration.

11. A safing and arming system according to claim 5, wherein the wiring assembly comprises electrical connections selected from the group consisting of: a short circuit connection to ground for the signal; a short circuit connection to ground for a detonator arming signal; a short circuit connection to ground for an electronic controller configured to control the detonator; and combinations thereof.

12. A safing and arming system adapted to be operably engaged with a projectile including an explosive train, the projectile being adapted to be launched from a launch bore, the system comprising: an arming switch configured to be movable from a first position to a second position, the arming switch being further configured to operably engage a detonator such that, when the arming switch is in the first position, the detonator operably engaged therewith is substantially out of alignment with the explosive train and such that, when the arming switch is in the second position, the detonator operably engaged therewith is substantially aligned with the explosive train such that the explosive train is capable of being armed; an actuator device operably engaged with the arming switch and configured to move the arming switch from the first position to the second position in response to a signal; and a proximity safety device configured to be capable of operably engaging the arming switch so as to normally retain the arming switch in the first position, the proximity safety device being further configured to sense an inner wall defining the launch bore so as to allow the arming switch to be moved to the second position when the projectile is launched from the launch bore, such that the arming switch is capable of being moved to the second position so that the explosive train is capable of being armed, the proximity safety device further comprising a tab configured to normally cover an optical sensor in communication with the detonator, the tab being configured to uncover the optical sensor when the projectile is launched from the launch bore such that the optical sensor is capable of transmitting the signal to the actuator device so that the actuator device is capable of moving the arming switch from the first position to the second position at a selected time after the projectile is launched from the launch bore.

13. A safing and arming system according to claim 12, wherein the proximity safety device further comprises: a first pin slidably disposed in a first pin channel, the first pin including a first end configured to contact the inner wall of the launch bore, the first pin also including a second end configured to engage the arming switch so as to normally retain the arming switch in the first position, the tab being configured to extend from the first pin so as to normally cover the optical sensor in communication with the detonator when the projectile is disposed within the launch bore; and a biasing element operably engaged with the first pin, and configured to bias the first pin towards the inner wall of the launch bore such that, when the projectile is launched from the launch bore, the first end of the first pin becomes unconstrained, and the second end of the first pin disengages the arming switch so that the actuator device is capable of moving the arming switch to the second position, such that the explosive train in capable of being armed and such that the tab uncovers the optical sensor so that the optical sensor is capable of transmitting the signal to the actuator device to move the arming switch from the first position to the second position at a selected time after the projectile is launched from the launch bore.

14. A safing and arming system according to claim 12, further comprising a first acceleration safety device configured to be capable of operably engaging the arming switch so as to normally retain the arming switch in the first position, the first acceleration safety device being further configured to disengage the arming switch in response to an acceleration force having a selected magnitude and a selected duration, the acceleration force being imparted on the first acceleration safety device by an acceleration of the projectile with respect to the launch bore during a launch of the projectile.

15. A safing and arming system according to claim 12, further comprising: a wiring assembly configured to short circuit the signal to prevent the signal from being transmitted to the actuator device; and a second acceleration safety device configured to be capable of disabling the wiring assembly in response to a force having a selected magnitude and a selected duration, imparted on the second acceleration safety device by an acceleration of the projectile with respect to the launch bore during a launch of the projectile such that the signal is capable of being transmitted to the actuator device.

16. A safing and arming system according to claim 12, wherein the arming switch comprises a rotatable cylinder having a central axis and defining an arming channel extending radially outward from the central axis, the arming channel being configured to receive the detonator such that, as the rotatable cylinder is rotated from the first position to the second position, the detonator becomes substantially aligned with the explosive train so that the explosive train is capable of being armed.

17. A safing and arming system according to claim 14, wherein the first acceleration safety device comprises: a first setback weight slidably disposed in a first setback weight chamber; a second pin configured to be capable of operably engaging the arming switch so as to normally retain the arming switch in the first position; and a first linkage arm operably engaged between the first setback weight and the second pin such that, as the first setback weight slides within the first setback weight chamber in response to the acceleration force, the first linkage arm is configured to disengage the second pin from the arming switch so as to allow the arming switch to be moved to the second position.

18. A safing and arming device according to claim 17, wherein the first setback weight is configured to slide within the first setback weight chamber in response to the acceleration force having the selected magnitude and the selected duration.

19. A safing and arming system according to claim 15, wherein the second acceleration safety device comprises: a second setback weight slidably disposed in a second setback weight chamber; a cutting device slidably disposed in a cutting channel; and a second linkage arm operably engaged between the second setback weight and the cutting device such that, as the second setback weight slides within the second setback weight chamber in response to the acceleration force, the second linkage arm is configured to move the cutting device within the cutting channel such that the cutting device cuts at least one wire within the wiring assembly so that the signal is capable of being transmitted to the actuator device.

20. A safing and arming device according to claim 19, wherein the second setback weight is configured to slide within the second setback weight chamber in response to the acceleration force having the selected magnitude and the selected duration.

21. A safing and arming system according to claim 15, wherein the wiring assembly comprises electrical connections selected from the group consisting of: a short circuit connection to ground for the signal; a short circuit connection to ground for a detonator arming signal; a short circuit connection to ground for an electronic controller configured to control the detonator; and combinations thereof.

22. A method for safing and arming a projectile including an explosive train, using a safing and arming system, the projectile being adapted to be launched from a launch bore, the method comprising: securing an arming switch in a first position so as to normally retain the arming switch in the first position, the arming switch being configured to be movable from the first position to a second position, and to operably engage a detonator such that, when the arming switch is in the first position, the detonator operably engaged therewith is substantially out of alignment with the explosive train and such that, when the arming switch is in the second position, the detonator operably engaged therewith is substantially aligned with the explosive train such that the explosive train is capable of being armed; releasing the arming switch so as to allow the arming switch to be moved to the second position, the arming switch being released in response to: an acceleration force having a selected magnitude and a selected duration, the acceleration force being imparted on the projectile by an acceleration of the projectile with respect to the launch bore during a launch of the projectile; and a determination that the projectile has been launched from the launch bore.

23. A method according to claim 22, wherein the securing step further comprises: securing the arming switch in the first position with a first acceleration safety device configured to be capable of operably engaging the arming switch so as to normally retain the arming switch in the first position; and securing the arming switch in the first position with a proximity safety device configured to be capable of operably engaging the arming switch so as to normally retain the arming switch in the first position, the proximity safety device being further configured to sense an inner wall defining the launch bore.

24. A method according to claim 22, wherein the releasing step further comprises: disengaging a first acceleration safety device from the arming switch so as to allow the arming switch to be moved to the second position, in response to an acceleration force having a selected magnitude and a selected duration, the acceleration force being imparted on the first acceleration safety device by an acceleration of the projectile with respect to the launch bore during a launch of the projectile; sensing the inner wall of the launch bore with a proximity safety device; determining when the inner wall is no longer sensed by the proximity safety device, after disengaging the first acceleration safety device from the arming switch; and disengaging the proximity safety device from the arming switch after the determining step so as to allow the arming switch to be moved to the second position such that the explosive train is capable of being armed when the projectile is launched from the launch bore.

25. A method according to claim 24, wherein the proximity safety device comprises a first pin slidably disposed in a first pin channel, and the method further comprises: contacting an inner wall of the launch bore with a first end of the first pin when the projectile is disposed within the bore; engaging a second end of the first pin with the arming switch so as to normally retain the arming switch in the first position when the projectile is disposed within the bore; and biasing the first pin towards the inner wall of the launch bore, with a biasing element operably engaged therewith, such that, when the projectile is launched from the launch bore, the first end of the first pin becomes unconstrained, and the second end of the first pin disengages the arming switch such that the arming switch is capable of being moved to the second position so that the explosive train is capable of being armed.

26. A method according to claim 24, further comprising moving the arming switch from the first position to the second position, with an actuator device operably engaged therewith, in response to a signal received by the actuator device.

27. A method according to claim 26, wherein the proximity safety device comprises a tab configured to normally cover an optical sensor in communication with the detonator and the actuator device, and the method further comprises: moving the tab so as to uncover the optical sensor when the projectile is launched from the launch bore such that the optical sensor is capable of transmitting the signal to the actuator device; and transmitting the signal from the optical sensor to the actuator device such that the actuator device is capable of moving the arming switch from the first position to the second position at a selected time after the projectile is launched from the launch bore.

28. A method according to claim 26, further comprising: Normally short-circuiting the signal with a wiring assembly to prevent the signal from being transmitted to the actuator device; disabling the wiring assembly in response to the acceleration force with a second acceleration safety device such that the signal is capable of being transmitted to the actuator device; and transmitting the signal to the actuator device such that the actuator device is capable of moving the arming switch from the first position to the second position.

29. A method for safing and arming a projectile including an explosive train, using a safing and arming system, the projectile being adapted to be launched from a launch bore, the method comprising: securing an arming switch in a first position so as to normally retain the arming switch in the first position, the arming switch being configured to be movable from the first position to a second position, and to operably engage a detonator such that, when the arming switch is in the first position, the detonator operably engaged therewith is substantially out of alignment with the explosive train and such that, when the arming switch is in the second position, the detonator operably engaged therewith is substantially aligned with the explosive train such that the explosive train is capable of being armed; determining when the projectile has exited the launch bore; releasing the arming switch so as to allow the arming switch to be moved to the second position after a selected time period following the determining step; uncovering an optical sensor configured to transmit a signal; transmitting the signal to an actuator device operably engaged with the arming switch; and moving the arming switch from the first position to the second position with the actuator device, in response to the transmitted signal, at a selected time after the transmitting step.

30. A method according to claim 29, wherein the securing step further comprises securing the arming switch in the first position with a proximity safety device configured to be capable of operably engaging the arming switch so as to normally retain the arming switch in the first position, the proximity safety device further comprising a tab configured to normally cover an optical sensor in communication with the detonator, the proximity safety device being further configured to sense an inner wall of the launch bore.

31. A method according to claim 30, further comprising: determining when the inner wall of the launch bore is no longer sensed by the proximity safety device; disengaging the proximity safety device from the arming switch after the determining step so as to allow the arming switch to be moved to the second position such that the explosive train is capable of being armed when the projectile is launched from the launch bore; and moving the tab so as to uncover the optical sensor such that the optical sensor is capable of transmitting the signal.

32. A method according to claim 30, further comprising: contacting the inner wall of the launch bore with a first end of a first pin when the projectile is disposed within the launch bore, the first pin being slidably disposed in a first pin channel defined by the system and having the tab operably engaged therewith; engaging a second end of the first pin with the arming switch so as to normally retain the arming switch in the first position when the projectile is disposed within the launch bore; and biasing the first pin towards the inner wall of the launch bore, with a biasing element operably engaged with the first pin such that, when the projectile is launched from the launch bore, the first end of the first pin becomes unconstrained, and the second end of the first pin disengages the arming switch such that the arming switch is capable of being moved to the second position so that the explosive train is capable of being armed.

33. A method according to claim 29, further comprising: securing the arming switch in the first position with a first acceleration safety device; and disengaging the first acceleration safety device from the arming switch so as to allow the arming switch to be moved to the second position, in response to an acceleration force having a selected magnitude and a selected duration, the acceleration force being imparted on the first acceleration safety device by an acceleration of the projectile with respect to the launch bore during a launch of the projectile.

34. A method according to claim 29, further comprising: Normally short-circuiting the signal with a wiring assembly to prevent the signal from being transmitted to the actuator device; disabling the wiring assembly in response to the acceleration force with a second acceleration safety device such that the signal is capable of being transmitted to the actuator device; and transmitting the signal to the actuator device such that the actuator device is capable of moving the arming switch from the first position to the second position.

35. A method according to claim 34, wherein the disabling step comprises cutting at least one wire within the wiring assembly such that the signal is capable of being transmitted to the actuator device.

Description:

FIELD OF THE INVENTION

Various embodiments of the present invention relate generally to a system and method for safing and arming a bore-launched projectile so as to prevent unintended arming of the projectile.

BACKGROUND OF THE INVENTION

Munitions (such as explosive projectiles) are often provided with a safing and arming (“SA”) device that is designed to allow the projectile to arm its explosive train (and consequently, in some cases, the warhead carried by the projectile) only after the projectile has undergone an intentional launch event. For example, all munitions qualified by the United States government must comply with the requirements of U.S. Department of Defense (“DOD”) MIL-STD-1316, entitled “Safety Criteria for Fuze Design,” which sets forth specific guidelines and requirements for the design of an acceptable SA device. For example, MIL-STD-1316 specifies that an acceptable SA device must sense two independent arming environments prior to arming.

Conventional SA devices carried by bore-launched explosive projectiles utilize simultaneous acceleration and spin imparted by a gun launch as the two independent arming environments to indicate an intentional launch event. However, there exists a growing class of munitions that do not produce spin upon gun launch and that experience relatively low acceleration forces (i.e. low-g acceleration) during launch. Such no-spin, low-g munitions present problems for conventional SA devices since the magnitude of a launch acceleration force is typically lower than that resulting from an accidental drop of the projectile (i.e. when loading and/or handling the projectile prior to launch). Furthermore, conventional SA devices do not utilize electronic safety back-up systems that are capable of reliably identifying an intentional launch event and/or positively preventing the arming of an explosive projectile (via hard-wired and/or switched short circuits) during non-launch events (such as an accidental drop). Therefore, conventional SA devices may have some shortcomings, especially when applied to newer no-spin and/or low-g bore-launched munitions.

Thus, there exists a need for SA devices capable of distinguishing between an intentional launch and an accidental drop of a projectile equipped with such an SA device. Furthermore, there exists a need for SA devices capable of sensing arming environments other than projectile spin, so as to be compatible with no-spin bore-launched projectiles, while still providing an independent safeguard against an accidental arming and/or detonation. There also exists a need for SA devices that provide parallel electronic safeguards against accidental and/or unintentional arming of an explosive projectile that may be coupled to one or more of the arming environments sensed by the SA device.

BRIEF SUMMARY OF THE INVENTION

Various embodiments presented herein provide technical solutions to many of the problems inherent in conventional SA devices while providing robust and, in some cases, multiple independent safeguards against accidental arming of a projectile. According to various embodiments of the present invention, a safing and arming system is provided to be operably engaged with a projectile adapted to be launched from a launch bore.

In one embodiment, the system comprises an arming switch configured to be movable from a first position to a second position. The arming switch is further configured to operably engage a detonator, such that when the arming switch is in the first position, the detonator is substantially out of alignment with the explosive train. Furthermore, the arming switch is further configured such that when the arming switch is in the second position, the detonator is substantially aligned with the explosive train such that the explosive train is capable of being armed. In some embodiments, the arming switch comprises a rotatable cylinder having a central axis and defining an arming channel extending radially outward from the central axis. Furthermore, in such embodiments, the arming channel is configured to receive the detonator such that as the rotatable cylinder is rotated from the first position to the second position, the detonator is substantially aligned with the explosive train such that the explosive train is capable of being armed. In some embodiments, the system further comprises an actuator device operably engaged with the arming switch. In such embodiments, the actuator device is configured to be capable of moving the arming switch from the first position to the second position in response to a signal.

According to some system embodiments, the system further comprises a first acceleration safety device configured to be capable of operably engaging the arming switch so as to normally retain the arming switch in the first position. Furthermore, the first acceleration safety device is configured to disengage the arming switch so as to allow the arming switch to be moved to the second position, in response to an acceleration force having a selected magnitude and a selected duration. For example, the acceleration force may be imparted on the first acceleration safety device by an acceleration of the projectile with respect to the launch bore during a launch of the projectile.

In some system embodiments, the first acceleration safety device comprises: a first setback weight slidably disposed in a first setback weight chamber; a second pin configured to be capable of operably engaging the arming switch so as to normally retain the arming switch in the first position; and a first linkage arm operably engaged between the first setback weight and the second pin. Thus, in such embodiments, in response to the acceleration force, the first setback weight slides within the first setback weight chamber and the first linkage arm is configured to disengage the pin from the arming switch so as to allow the arming switch to be moved to the second position. In some embodiments, the first setback weight is configured to slide within the first setback weight chamber in response to the acceleration force having the selected magnitude and the selected duration.

The system may also further comprise a proximity safety device configured to operably engage the arming switch so as to normally retain the arming switch in the first position. The proximity safety device is further configured to sense an inner wall of the launch bore. The proximity safety device is further configured to allow the arming switch to be moved to the second position such that the explosive train is capable of being armed when the projectile is launched from the launch bore. In some embodiments, the proximity safety device comprises a first pin slidably disposed in a first pin channel, wherein the first pin includes a first end configured to contact an inner wall of the launch bore, and a second end configured to engage the arming switch so as to normally retain the arming switch in the first position when the projectile is disposed within the launch bore. In such embodiments, the proximity safety device further comprises a biasing element operably engaged with the first pin for biasing the first pin towards the inner wall of the launch bore such that when the projectile is launched from the launch bore, the first end of the first pin becomes unconstrained, and the second end of the first pin disengages the arming switch such that the arming switch is capable of being moved to the second position so that the explosive train is capable of being armed.

According to some system embodiments, the proximity safety device further comprises a tab configured to normally cover an optical sensor in communication with the detonator. In such embodiments, the optical sensor is configured to be capable of transmitting the signal to the actuator device when the tab is moved to uncover the optical sensor. The tab of the proximity safety device is further configured to uncover the optical sensor when the projectile is launched from the launch bore such that the optical sensor is capable of transmitting the signal to the actuator device. Thus, in such embodiments, the actuator device may be rendered capable of moving the arming switch from the first position to the second position at a selected time after the projectile is launched from the launch bore.

Some system embodiments of the present invention further comprise a wiring assembly configured to short circuit the signal to prevent the signal from being transmitted to the actuator device. In some such system embodiments, the wiring assembly may comprise electrical connections including, but not limited to: a short circuit connection to a ground for the signal; a short circuit connection to a ground for a detonator arming signal; a short circuit connection to a ground for an electronic controller configured to control the detonator; and combinations of such electrical connections. In some embodiments, the system further comprises a second acceleration safety device configured to be capable of disabling the wiring assembly in response to the acceleration force such that the signal is capable of being transmitted to the actuator device. The second acceleration safety device may comprise: a second setback weight slidably disposed in a second setback weight chamber; a cutting device slidably disposed in a cutting channel; and a second linkage arm operably engaged between the second setback weight and the cutting device such that as the second setback weight slides within the second setback weight chamber in response to the acceleration force, the second linkage arm is configured to move the cutting device within the cutting channel such that the cutting device cuts at least one wire within the wiring assembly such that the signal is capable of being transmitted to the actuator device. As described herein with respect to the first acceleration safety device, the second setback weight provided in some system embodiments may also be configured to slide within the second setback weight chamber in response to the acceleration force having the selected magnitude and the selected duration.

Various embodiments of the present invention also provide a method for safing and arming a projectile including an explosive train, using a safing and arming system. As described herein, the projectile is adapted to be launched from a launch bore. In some embodiments, the method first comprises securing an arming switch in a first position so as to normally retain the arming switch in the first position wherein the arming switch is configured to be movable from the first position to a second position. The arming switch is further configured to operably engage a detonator, such that when the arming switch is in the first position, the detonator is substantially out of alignment with the explosive train and such that when the arming switch is in the second position, the detonator is substantially aligned with the explosive train such that the explosive train is capable of being armed. The method further comprises a step for releasing the arming switch so as to allow the arming switch to be moved to the second position. According to some method embodiments, the arming switch may be released by: an acceleration force having a selected magnitude and a selected duration, the acceleration force being imparted on the first acceleration safety device by an acceleration of the projectile with respect to the launch bore during a launch of the projectile; and a determination that the projectile has been launched from the launch bore.

According to some method embodiments, the securing step described herein further comprises securing the arming switch in the first position with a first acceleration safety device configured to be capable of operably engaging the arming switch so as to normally retain the arming switch in the first position. Furthermore, the securing step may also further comprise securing the arming switch in the first position with a proximity safety device configured to be capable of operably engaging the arming switch so as to normally retain the arming switch in the first position, wherein the proximity safety device is further configured to sense an inner wall defining the launch bore.

Furthermore, the releasing step may further comprise disengaging a first acceleration safety device from the arming switch so as to allow the arming switch to be moved to the second position, in response to an acceleration force having a selected magnitude and a selected duration. As described herein, the acceleration force may be imparted on the first acceleration safety device by an acceleration of the projectile with respect to the launch bore during a launch of the projectile. Furthermore, the releasing step may also further comprise steps including, but not limited to: sensing the inner wall of the launch bore with a proximity safety device; determining when the inner wall is no longer sensed by the proximity safety device, after disengaging the first acceleration safety device from the arming switch; and disengaging the proximity safety device from the arming switch after the determining step so as to allow the arming switch to be moved to the second position such that the explosive train is capable of being armed when the projectile is launched from the launch bore. According to some such method embodiments, the proximity safety device comprises a first pin slidably disposed in a first pin channel. In such embodiments, the method may further comprise steps including, but not limited to: contacting an inner wall of the launch bore with a first end of the first pin when the projectile is disposed within the bore; engaging a second end of the first pin with the arming switch so as to normally retain the arming switch in the first position when the projectile is disposed within the bore; and biasing the first pin towards the inner wall of the launch bore. The biasing step may be accomplished in some embodiments with a biasing element operably engaged with the first pin. Thus, when the projectile is launched from the launch bore, the first end of the first pin becomes unconstrained, and the second end of the first pin disengages the arming switch such that the arming switch is capable of being moved to the second position so that the explosive train is capable of being armed.

Additional method embodiments of the present invention may further comprise steps for moving the arming switch from the first position to the second position with an actuator device operably engaged therewith, in response to a signal received by the actuator device. In such embodiments, the method may comprise normally short-circuiting the signal with a wiring assembly to prevent the signal from being transmitted to the actuator device. The method may also further comprise disabling the wiring assembly in response to the acceleration force with a second acceleration safety device such that the signal is capable of being transmitted to the actuator device. The method may also further comprise transmitting the signal to the actuator device such that the actuator device is capable of moving the arming switch from the first position to the second position. Furthermore, in some method embodiments, the proximity safety device comprises a tab configured to normally cover an optical sensor in communication with the detonator. Such method embodiments may further comprise steps for: moving the tab so as to uncover the optical sensor when the projectile is launched from the launch bore such that the optical sensor is capable of transmitting the signal to the actuator device; and transmitting a signal from the optical sensor to the actuator device such that the actuator device is capable of moving the arming switch from the first position to the second position at a selected time after the projectile is launched from the launch bore.

Thus, various embodiments of a safing and arming system and associated method according to the present invention may provide one or more advantages that may include, for example: providing a robust mechanical safing system that allows a projectile to arm only after an intentional launch event; providing a safing system that is capable of discerning between acceleration loads resulting from a launch event and a shock load resulting from rough handling and/or an accidental drop; providing a parallel optical and/or electronic safing system that is capable of activating an electronic arming system; providing a safing and arming system that is compatible with “no-spin” bore-launched projectiles having relatively low launch acceleration rates; and providing a readily-adjustable mechanical safing mechanism that may be adjusted to function under a wide range of launch acceleration conditions.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

Having thus described various embodiments in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

FIG. 1 shows an exemplary exploded schematic depiction of a safing and arming system according to one embodiment of the present invention;

FIG. 2 shows an exemplary cross-sectional schematic view of a safing and arming system installed in a bore-launched projectile according to one embodiment of the present invention;

FIG. 3 shows an exemplary schematic of a safing and arming system according to one embodiment of the present invention, including a first acceleration safety device and a proximity safety device operably engaged with a rotatable arming switch;

FIG. 4A shows a schematic view of a first side of a rotatable arming switch defining a bearing surface configured to be operably engaged with a piston actuator for operating a safing and arming system according to one embodiment of the present invention;

FIG. 4B shows a schematic view of a second side of a rotatable arming switch defining a shear pin channel configured to be operably engaged with a shear pin for operating a safing and arming system according to one embodiment of the present invention;

FIG. 4C shows a schematic cut-away view of a rotatable arming switch defining a detonator channel configured to carry a detonator as part of a safing and arming system according to one embodiment of the present invention;

FIG. 4D shows a schematic end view of a rotatable arming switch including a bearing surface operably engaged with a piston actuator for operating a safing and arming system according to one embodiment of the present invention;

FIG. 5 shows a schematic view of a first acceleration safety device forming a part of a safing and arming system according to one embodiment of the present invention;

FIG. 6 shows a schematic view of a proximity safety device forming a part of a safing and arming system according to one embodiment of the present invention;

FIG. 7 shows a schematic view of a second acceleration safety device forming a part of a safing and arming system according to one embodiment of the present invention;

FIG. 8 shows a cross-sectional schematic of a safing and arming system according to one embodiment of the present invention, wherein the arming switch is in a safe position and a first acceleration safety device and a proximity safety device are engaged with the arming switch to retain the arming switch in the safe position;

FIG. 9 shows a cross-sectional schematic of a safing and arming system according to one embodiment of the present invention, wherein the arming switch is in a safe position and a first acceleration safety device is disengaged from the arming switch in response to an acceleration force;

FIG. 10 shows a cross-sectional schematic of a safing and arming system according to one embodiment of the present invention, wherein the arming switch is in a safe position, a first acceleration safety device is disengaged from the arming switch in response to an acceleration force, and a proximity safety device is disengaged from the arming switch;

FIG. 11 shows a cross-sectional schematic of a safing and arming system according to one embodiment of the present invention, wherein the arming switch is in an armed position;

FIG. 12 shows a cross-sectional schematic of a safing and arming system according to one embodiment of the present invention, including a second acceleration safety device, wherein the second acceleration safety device is positioned so as to complete a short circuit; and

FIG. 13 shows a cross-sectional schematic of a safing and arming system according to one embodiment of the present invention, including a second acceleration safety device, wherein the second acceleration safety device is positioned so as to disable a wiring assembly.

DETAILED DESCRIPTION OF THE INVENTION

Various embodiments of a system and associated method for safing and arming a bore-launched projectile now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments are shown. Indeed, system and method may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.

While the various system 1 and method embodiments of the present invention are described in the context of a safing and arming system 1 having a rotatable arming switch 10 (see FIGS. 4A-4D, for example), it should be understood that the various SA system 1 and method embodiments described herein may also be applied to a linearly slidable arming switch (not shown) wherein at least one of the first acceleration safety device 30, the second acceleration safety device 60, and the proximity safety device 40, otherwise described herein, may be configured to retain the linearly slidable arming switch (and a detonator 11 carried thereby) normally out of alignment with an explosive train. Furthermore, while various safing and arming systems 1 and methods are described herein in the context of a “no-spin” bore-launched projectile (adapted to be launched from a smooth bore tube, for example), it should be understood that the various embodiments described herein may also be used in conjunction with projectiles imparted with a spin upon launch (such as explosive projectiles launched from a barrel or launch tube having a rifled bore, for example). In addition, it should be understood that the various system and method embodiments disclosed herein may be used in conjunction with any number of projectile types having an explosive train configured to detonate an explosive warhead (such as a high explosive anti-tank (HEAT) round, for example) and/or configured to initiate the launch of a kinetic energy penetrator device from a sabot, for example.

Embodiments of the present invention include a safing and arming (SA) system 1 (see FIG. 1, for example) adapted to be operably engaged with a projectile 100 including an explosive train (such as a series of explosive charges carried by the projectile 100 for exploding a warhead 101, for example, as shown in FIG. 2). As shown generally in FIG. 2, the SA system 1 may be disposed substantially adjacent to the explosive train as part of a projectile 100 that is adapted to be launched from a launcher 200 defining a launch bore 202.

In some embodiments, such as that shown generally in FIG. 1, the SA system 1 comprises an arming switch 10 that may be carried by a system housing 20. As shown generally in the cross-sectional schematics of FIGS. 10 and 11, the arming switch 10 may be configured to be movable from a first position (see FIG. 10, for example) to a second position (see FIG. 11, for example). Furthermore, as shown generally in FIG. 4C, the arming switch 10 may be further configured to operably engage a detonator 11 (such as an M55 detonator device, for example), such that when the arming switch 10 is in the first position, the detonator 11 is substantially out of alignment with the explosive train (see FIG. 10, for example), and such that, when the arming switch 10 is in the second position, the detonator 11 is substantially aligned with the explosive train such that the explosive train is capable of being armed (see FIG. 11, for example).

According to some embodiments, as shown generally in FIGS. 4A-4D, the arming switch 10 may comprise a rotatable cylinder having a central axis and defining an arming channel 10F extending radially outward from the central axis. As shown in FIG. 4C, the arming channel 10F defined by the arming switch 10 may be configured to receive the detonator 11 such that, as the rotatable cylinder is rotated from the first position to the second position, the detonator 11 is substantially aligned with the explosive train of the projectile 100 such that the explosive train is capable of being armed. According to some such embodiments, the arming channel 10F defined by the arming switch 10 may be further configured to receive an explosive lead element 13 such that the explosive lead element 13 is disposed substantially between the detonator 11 and a primary explosive charge (and/or warhead) carried by the projectile 100. Thus, when the arming switch 10 is in the second (armed) position (see FIG. 11), the explosive lead element 13 may, in some embodiments, act as a transfer charge between the detonator 11 and the primary explosive charge (and/or warhead) carried by the projectile 100. For example, in some embodiments, the detonator 11 may comprise an M55 “stab” detonator configured to initiate the explosive lead element 13 which, in turn, may be configured to produce a sufficient explosive output to initiate the detonation of the primary explosive charge (and/or warhead) carried by the projectile 100. Thus, the explosive lead element 13 may increase the reliability of the arming and detonation mechanism of the projectile 100.

Furthermore, the arming switch 10 may comprise, for example, a metal and/or metallic alloy exhibiting relatively robust dimensional stability and corrosion resistance so as to further improve the reliability of the arming switch 10. For example, in some embodiments, the arming switch 10 may comprise a stainless steel material (such as 303 stainless steel) machined as shown generally in FIGS. 4A-4C and as described further herein so as to be compatible with various types of acceleration safety devices (see generally, element 30, FIG. 3) and proximity safety devices (see generally, element 40, FIG. 3). According to some SA system 1 embodiments (as shown in FIG. 8, for example), the arming switch 10 may define a locking channel 10C configured to be capable of receiving a pin 33 of a first acceleration safety device 30 (FIG. 5) and/or a second end 45 of a bore rider pin 44 (FIG. 6) included as part of a proximity safety device 40.

As shown in FIG. 3, the SA system 1 may further comprise a first acceleration safety device 30 carried by the system housing 20 (see FIG. 1, showing an exploded view of the SA device 1 including the system housing 20 depicted relative to the arming switch 10). The first acceleration safety device 30 is configured to be capable of operably engaging the arming switch 10 (via a pin 33, for example, as shown in FIG. 3) so as to normally retain the arming switch 10 in the first position (see FIG. 10, showing the arming switch 10 substantially out of alignment with an explosive train of a projectile). The first acceleration safety device 30 may be further configured to disengage the arming switch 10 (as shown in FIG. 9, for example) so as to allow the arming switch 10 to be moved to the second position in response to an acceleration force having a selected magnitude and a selected duration. As shown in FIG. 2, the acceleration force may be imparted on the first acceleration safety device 30 (carried by the system housing 20 of the SA system 1) by an acceleration of the projectile 100 with respect to the launcher 200 during a launch of the projectile in the launch direction 300.

For example, in some embodiments, as shown in FIG. 5, the first acceleration safety device 30 comprises a first setback weight 31 slidably disposed in a first setback weight chamber 22 defined by the system housing 20 (see FIG. 1). In addition, the first acceleration safety device 30 comprises a pin 33 configured to be capable of operably engaging the arming switch 10 (by extending into the locking channel 10C defined by the arming switch 10, for example) so as to normally retain the arming switch 10 in the first position (see FIG. 8, elements 33 and 10C). In order to link the release of the pin 33 from the locking channel 10C with the movement of the first setback weight 31 within the first setback weight chamber 22, the first acceleration safety device 30 further comprises a first linkage arm 32 operably engaged between the first setback weight 31 and the pin 33 such that, as the first setback weight 31 slides within the first setback weight chamber 22 (in response to the acceleration force, for example), the first linkage arm 32 is configured to disengage the pin 33 from the arming switch 10 (or, more particularly, the locking channel 10C that may be defined thereby) so as to allow the arming switch 10 to be moved to the second position (see, for example, FIG. 11, showing the first acceleration device 30 and the proximity device 40 (described further herein) disengaged from the arming switch 10 such that the arming switch 10 is movable to the second “armed” position). As will be appreciated by one skilled in the art, in some embodiments, various characteristics of the first setback weight 31 (and other components of the first acceleration safety device 30) may be selected such that the first setback weight 31 is configured to slide within the first setback weight chamber 22, defined by the system housing 20, in response to an acceleration force having a selected magnitude and a selected duration. Furthermore, as shown generally in FIG. 5, the first acceleration device 30 may further comprise a cantilever spring 34 operably engaged between the first setback weight 31 and the system housing 20 so as to provide a selected amount of resistance to sliding movement of the first setback weight 31 within the first setback weight chamber 22 defined by the system housing 20. Thus, in such embodiments, the characteristics (such as, for example, spring rate, stiffness, and/or other mechanical properties) of the cantilever spring 34 may be selected such that the cantilever spring 34, in conjunction with the mechanical properties of the first setback weight 31, allows the first setback weight 31 to slide within the first setback weight chamber 22 only in response to an acceleration force having a selected magnitude and a selected duration. Thus, the first acceleration safety device 30 may be configured only to allow arming of the explosive train (by disengaging the arming switch 10, for example, as shown generally in FIG. 9) in response to acceleration force intensity and/or duration that is indicative of an intentional launch of the projectile 100 (as opposed to relatively short-duration acceleration forces resulting from accidental drops and/or rough handling of the projectile 100). Furthermore, in order to increase the likelihood that the first acceleration safety device 30 remains operable and robust for the projected storage life of the projectile 100, the components thereof may be comprised of particularly selected materials for corrosion resistance and enhanced mechanical properties. For example, in some embodiments, the first setback weight 31 and the pin 33 may be formed of 303 stainless steel. Furthermore, in some embodiments, the first linkage arm 32 may be formed of aluminum or an aluminum alloy (such as, for example, 6061-T651 aluminum). By selecting the particular characteristics of the first setback weight 31, cantilever spring 34, the pin 33, and/or the first linkage arm 32, the embodiments of the SA system 1 may be configured such that projectiles having relatively low-g loads during launch may still be reliably armed without compromising the safing capabilities of an SA system 1 according to embodiments of the present invention. In other embodiments, the mass, weight, and or geometry of the first setback weight 31 may be customized for the specific launch conditions of the particular projectile 100 that is configured to carry the SA system 1 such that the first setback weight 31 is configured to initiate the disengagement of the pin 33 from the arming switch 10 (see FIG. 9, for example) only in response to acceleration conditions that are indicative of an intentional launch of the projectile 100.

As shown in FIG. 3, the SA system 1 may further comprise a proximity safety device 40 carried by the system housing 20 (see FIG. 1, showing an exploded view of the components of the proximity safety device 40 relative to the system housing 20). As shown in FIG. 3, the proximity safety device 40 (and/or a bore rider pin 44 thereof) is configured to be capable of operably engaging the arming switch 10 so as to normally retain the arming switch 10 in the first position. Furthermore, as shown generally in FIG. 2, the proximity safety device 40 (and/or a bore rider pin 44 thereof) is further configured to sense an inner wall 201 of the launch bore 202 so as to allow the arming switch 10 to be moved to the second position (see FIG. 11, for example) such that the explosive train is capable of being armed when the projectile 100 is launched from the launch bore 202. The proximity safety device 40 may comprise, in some embodiments, a bore rider pin 44 biased radially outward from the system housing 20 so as to contact and therefore sense or detect the inner wall 201 defining the launch bore 202 when the projectile 100 is positioned within the launch bore 202.

For example, as shown in FIGS. 3 and 5, the proximity safety device 40 may comprise a bore rider pin 44 slidably disposed in a pin channel 20A defined by the system housing 20 (see also, the cross-sectional schematics of the SA system 1 shown in FIGS. 8-11). The bore rider pin 44 includes a first end 44A configured to contact the inner wall 201 of the launch bore 202 and a second end 45 configured to engage the arming switch 10 (i.e. to extend into a locking channel 10C defined therein) so as to normally retain the arming switch 10 in the first position (see FIG. 9, for example) when the projectile 100 is disposed within the bore 202. As shown in FIGS. 1 and 3, the proximity safety device 40 may comprise a biasing element 41 (such as a coil spring, for example) operably engaged between the system housing 20 and the bore rider pin 44 (and/or a spring tab 46 extending outward from the bore rider pin 44) so as to bias the bore rider pin 44 towards the inner wall 201 of the launch bore 202 such that, when the projectile 100 is launched from the launch bore 202, the first (wall-sensing) end 44A of the bore-rider pin 44 becomes unconstrained, and the second end 45 of the bore rider pin 44 disengages the arming switch 10 (as shown generally in FIG. 10, for example) and such that the arming switch 10 is capable of being moved to the second position (as shown, for example, in FIG. 11). According to some SA system 1 embodiments, the bore rider pin 44 (and the tab 42 and spring tab 46 extending therefrom) may be formed of corrosion-resistant and reliably-machined material so as to increase the reliability of the proximity safety device 40. For example, in some embodiments, the bore rider pin 44 may be formed of 6061-T651 aluminum.

In other embodiments, the proximity safety device 40 may comprise one or more non-contact sensors configured to be capable of sensing the inner wall 201 of the launch bore 202. For example, the proximity safety device 40 may comprise one or more optical sensors, magnetic sensors, piezoelectric elements, and/or other sensors or transducer devices configured to sense the inner wall 201 defining the launch bore 202. Furthermore, the proximity safety device 40 (and/or one or more sensors thereof) may be in communication with an actuator device 50 configured to disengage the pin 44 from the locking channel 10C defined by the arming switch 10 so as to allow the arming switch 10 to be moved to the second position when the proximity safety device 40 has determined that the projectile 100 has exited the launch bore 202. As described further herein, various control elements may be in communication with an actuator device 50 in some embodiments of the SA system 1 to ensure that the arming switch 10 is not moved to the second (armed) position (see FIG. 11, for example) until a selected time after the proximity safety device 40 has determined that the projectile 100 has exited the launch bore 202 (so as to ensure that the projectile 100 and/or an explosive train carried thereby will not be armed until the projectile 100 has reached a pre-determined “safe” distance from the launch bore 202).

Thus, once the first acceleration safety device 30 and the proximity safety device 40 have been disengaged from the arming switch 10 (see FIGS. 9 and 10, respectively); the arming switch 10 may be capable of being moved to the second position (as shown, for example, in FIG. 11). In order to facilitate the movement of the arming switch 10 to the second (armed) position, the SA system 1, as shown in FIGS. 1 and 3, may further comprise an actuator device 50 operably engaged between the system housing 20 and the arming switch 10 and configured to be capable of moving the arming switch 10 from the first position to the second position in response to a signal, wherein the signal may be, for example, an electrical or other suitable signal. For example, as shown in FIG. 4D, in some embodiments, the actuator device 50 may comprise one or more electromechanical piston actuators capable of extending a piston 51 to engage a bearing surface 10A defined by a rotatable cylindrical arming switch 10 such that as the piston 51 extends, the arming switch 10 is moved from the first (safe) position (see FIG. 10, for example) to the second (armed) position (see FIG. 11, for example). In case of an accidental extension of the piston 51 while the first acceleration safety device 30 and the proximity safety device 40 are still engaged with the locking channel 10C of the arming switch 10 (as shown, for example, in FIG. 8), some embodiments of the SA system 1 may comprise an arming switch 10 defining a cutaway section 10E behind the bearing surface 10A such that the piston 51 may shear and/or penetrate the bearing surface 10A if the actuator device 50 is initiated when at least one of the first acceleration safety device 30 and the proximity safety device 40 are still engaged with the locking channel 10C of the arming switch 10.

According to some additional embodiments, the arming switch 10 may be provided with additional safety features to reduce the risk of unintentional and/or accidental movement and/or rotation of the arming switch 10 from the first (safe) position to the second (armed) position. For example, cylindrical embodiments of the arming switch 10 (see FIGS. 4A-4D, for example) may define a shear pin slot 10D (defined off-center from the axis of the cylindrical arming switch 10) for receiving a shear pin 14 (see FIGS. 1 and 3). According to some SA system 1 embodiments, the shear pin 14 may extend through one or more apertures defined by the system housing 20 (and through the shear pin slot 10D) for preventing the rotation of cylindrical arming switch 10 embodiments relative to the system housing 20 of the SA system 1. Furthermore, the shear pin 14 may be configured to predictably fail in response to a torque generated by the action of the piston 51 (and/or other actuator device 50 component) on a bearing surface 10A defined by the arming switch 10.

According to various embodiments, the actuator device 50, which is configured to move the arming switch 10 from the first position to the second (armed) position as shown in the sequential views of FIGS. 10 and 11, may be in communication with one or more control devices configured to generate a signal that may be required to initiate movement of the actuator device 50. The control devices may be disposed on a circuit board 80 that is operably engaged with the system housing 20 of the SA system 1 (see FIG. 1). In addition (and as described further herein), the actuator 50 may comprise, for example, an electromechanical device or other suitable device configured to be in communication with one or more of the control devices via a wiring assembly 62 (see FIG. 7, for example) configured to maintain a short circuit around the actuator device 50 so as to reduce the risk of the actuator device 50 unintentionally initiating the movement of the arming switch 10 to the second (armed) position. In other embodiments, as described herein, the actuator device 50 may be in communication with an optical sensor 43 (see FIGS. 1 and 3) configured to be capable of generating the initiating signal in response to a change in detected ambient optical conditions. As described further herein, the optical sensor 43 may be included as part of and/or be coupled with the proximity safety device 40 such that the optical sensor 43 generates the initiating signal for the actuator device 50 only after a selected time has elapsed since the proximity safety device 40 no longer senses the inner wall 201 defining the launch bore 202. Thus, the combination of the optical sensor 43 (and/or other control devices and/or wiring assemblies 62, as described further herein), may provide secondary safeguards (to supplement, for example, the first acceleration safety device 30 and proximity safety device 40 described herein) against the accidental, premature, and/or unintentional arming of the explosive train carried by the projectile 100. In addition, some SA system 1 embodiments, may further comprise one or more logic circuits carried by the circuit board 80 and configured to be in communication with the actuator device 50 and/or one or more of the first acceleration safety device 30 and the proximity safety device 40 to ensure that the mechanical disengagement of these devices from the arming switch 10 occurs according to a timing schedule and in an order that is indicative of an intentional launch event.

As shown, in FIGS. 3 and 6, the proximity safety device 40 (and/or the bore rider pin 44 that may be included as part of the proximity safety device 40) may further comprise a tab 42 configured to normally cover an optical sensor 43 in communication with the actuator device 50. As described generally herein, and as shown, for example in FIGS. 8-11, the optical sensor 43 may be operably engaged with the system housing 20 (and/or a circuit board 80 operably engaged therewith). Further, the tab 42 may be configured to uncover the optical sensor 43 when the projectile 100 is launched from the launch bore 202 such that the optical sensor 43 becomes capable of transmitting the signal to the actuator device 50 so that the actuator device 50 is capable of moving the arming switch 10 from the first position (see FIG. 10, for example) to the second (armed) position (see FIG. 11, for example) at a selected time after the projectile 100 is launched from the launch bore 202. For example, as shown generally in FIGS. 8-11, the tab 42 may be operably engaged with and/or integrated with the bore rider pin 44 of the proximity safety device 40. Therefore, according to such embodiments, when the bore rider pin 44 loses contact with the inner wall 201 defining the launch bore 202, the biasing element 41 urges the bore rider pin 44 outward from the system housing 20 (see FIG. 10, for example) such that the tab 42 uncovers and/or removes a substantially opaque barrier between a light source (not shown) and a light detection device (not shown) that may be included as part of the optical sensor 43. In response to the removal of the tab 42, one skilled in the art will appreciate that the optical sensor 43 may transmit the signal to the actuator device 50 so as to initiate the movement of the arming switch 10 to the second (armed) position (as shown generally in FIG. 11).

According to some additional embodiments, as shown generally in FIGS. 7, 12 and 13, the SA system 1 may further comprise a wiring assembly 62 disposed between the optical sensor 43 (and/or one or more of the control devices carried by the circuit board 80 of the SA system 1) and the actuator device 50. Furthermore, in some embodiments, the wiring assembly 62 may be disposed between an energy source (carried, for example, by the circuit board 80) and a device configured to be capable of initiating the detonation of the explosive train (such as, for example, the detonator 11 carried by the arming switch 10, as shown in FIGS. 4A-4C). Thus, the wiring assembly 62 may be configured to normally provide and maintain a short circuit around the actuator device 50 so as to reduce the risk of the actuator device 50 unintentionally initiating movement of the arming switch 10 to the second (armed) position. In some embodiments, the wiring assembly 62 may be configured to normally provide and maintain a short circuit around the detonator 11 (or other explosive component of an explosive train carried by the projectile 100) so as to reduce the risk of unintentionally actuating the explosive train (even if the arming switch 10 (and the detonator 11, carried thereby) are substantially aligned with the explosive train of the projectile 100). The wiring assembly 62 may comprise, in various SA system 1 embodiments, a normally closed switch (as shown, for example in FIG. 12, showing a slider switch 66 normally in electrical contact with one or more contacts carried by the wiring assembly 62). According to other SA system 1 embodiments, the wiring assembly 62 may comprise a substantially continuous set of electrical connections (established by wires, for example, as shown in FIG. 7). According to various SA system 1 embodiments, the electrical connections (established by wires (see element 66A) and/or contacts 66B disposed on the slider switch 66) may include, but are not limited to: a short circuit connection to ground for the signal transmitted between the optical sensor 43 and the actuator device 50; a short circuit connection to ground for a detonator 11 arming signal; a short circuit connection to ground for a controller device (such as a chip and/or other controller carried by the circuit board 80) configured to control the detonator 11; and combinations of such electrical connections.

The wiring assembly 62 may thus serve as at least one component of a second acceleration safety device 60 (see exploded components of a second acceleration safety device 60 as shown, for example, in FIG. 7). The various components of the second acceleration safety device 60 (including, for example, a second setback weight 61 and a second linkage arm 63) may thus be configured to be capable disabling the wiring assembly 62 in response to the acceleration force of the projectile 100 such that a signal is capable of being transmitted to the actuator device 50 and/or detonator 11 in order to align the explosive train and/or actuate the explosive train only after the projectile 100 has experienced an acceleration force having a selected magnitude and duration. As described above with respect to the first acceleration safety device 30, the second setback weight 61 of the second acceleration safety device 60 may comprise materials having a selected mass and/or density such that the second acceleration safety device 60 only disables the short circuit of the explosive train and/or actuator device 50 in response to acceleration force (produced by movement of the SA system 1 in the launch direction 300, for example) having an intensity and/or duration that is indicative of an intentional launch of the projectile 100 (as opposed to relatively short-duration acceleration forces resulting from accidental drops and/or rough handling of the projectile 100).

In some embodiments, as shown in FIG. 7 for example, the second acceleration safety device 60 may comprise a second setback weight 61 slidably disposed in a second setback weight chamber 27 defined by the system housing 20. The second acceleration safety device 60 may, in some embodiments, further comprise a cutting device 65 configured to be capable of cutting one or more wires 66A in the wiring assembly 62. Furthermore, the cutting device 65 may be slidably disposed in a cutting channel (not shown) defined by the system housing 20 (and/or a cutting channel defined between two halves 62A, 62B of the wiring assembly 62). In addition, the second acceleration safety device 60 may further comprise a second linkage arm 63 operably engaged between the second setback weight 61 and the cutting device 65 such that, as the second setback weight 61 slides within the second setback weight chamber 27 in response to the acceleration force, the second linkage arm 63 is configured to move the cutting device 65 within the cutting channel (via the interaction of a second linkage arm slot 63B and a cutting device bearing element 65B, for example) such that the cutting device 65 (and/or a cutting edge 65A defined thereby) cuts at least one wire 66A within the wiring assembly 62 so that a signal is capable of being transmitted to the actuator device 50 and/or the detonator 11. As described herein with respect to the first setback weight 31 (provided as a component in some embodiments including a first acceleration safety device 30), the second setback weight 61 may be configured to slide within the second setback weight chamber 27 in response to the acceleration force having a selected magnitude and a selected duration.

According to some additional embodiments, as shown in FIGS. 12-13, the second setback weight 61 of the second acceleration safety device 60 may be configured to slide within the second setback weight chamber 27 in response to an acceleration force imparted on the SA system 1 such that the second setback weight 61 initiates the disconnection of a contact between a slider switch 66 and the wiring assembly 62, via the second linkage arm 63.

A method for safing and arming a projectile 100 including an explosive train, using an SA system 1 that may be disposed substantially adjacent to the explosive train, is further provided in additional embodiments described herein. As described herein with respect to FIG. 2, the projectile 100 may be adapted to be launched from a launch bore 202. According to one embodiment, the method comprises providing an arming switch 10 carried by a system housing 20, wherein the arming switch 10 is configured to be capable of moving from a first position to a second position. The arming switch 10 is further configured to operably engage a detonator 11 (and/or carry a detonator 11, as shown generally in FIG. 4C, for example). Thus, when the arming switch 10 is in the first position (see FIG. 10), the detonator 11 is substantially out of alignment with the explosive train, and when the arming switch 10 is in the second (armed) position (see FIG. 11, for example), the detonator 11 is substantially aligned with the explosive train such that the explosive train is capable of being armed.

Such a method may further comprise securing the arming switch 10 in the first position so as to normally retain the arming switch 10 in the first position (see, for example, FIG. 8), and then selectively releasing the arming switch 10 (see, for example, FIG. 10) so as to allow the arming switch 10 to be moved to the second position (see, for example FIG. 11). As described herein with respect to the various SA system 1 embodiments, the releasing step may be triggered by various intentional launch indicators that may include, but are not limited to: an acceleration force having a selected magnitude and a selected duration, the acceleration force being imparted on the projectile 100 by an acceleration of the projectile 100 with respect to the launch bore 202 during a launch of the projectile 100; and a determination that the projectile 100 has been launched from the launch bore 202 (see FIG. 2, for example).

As described herein with respect to the SA system 1 embodiments, the securing step described herein may be accomplished by two or more safety devices (which may be, in some embodiments, mechanically independent). For example, in some method embodiments, the securing step may comprise securing the arming switch 10 in the first position using a first acceleration safety device 30 carried by the system housing 20 and configured to be capable of operably engaging the arming switch 10 (and/or a locking channel 10C defined therein, as shown in FIGS. 8-11) so as to normally retain the arming switch 10 in the first (safe) position. The securing step may also further comprise securing the arming switch 10 in the first position using a proximity safety device 40 (which may comprise a bore rider pin 44, as described in the SA system 1 embodiments) configured to be capable of operably engaging the arming switch 10 (and/or a locking channel 10C defined therein, as shown in FIGS. 8-11) so as to normally retain the arming switch 10 in the first (safe) position. As described further herein, the proximity safety device 40 may be configured to sense the inner wall 201 of the launch bore 202 such that the proximity safety device 40 disengages the arming switch 10 only at some selected time after the projectile 100 has exited the launch bore 202.

As shown generally in FIG. 9, the releasing step may further comprise disengaging a first acceleration safety device 30 from the arming switch 10 so as to allow the arming switch 10 to be moved to the second position, in response to an acceleration force having a selected magnitude and a selected duration, with the acceleration force being imparted on the first acceleration safety device 30 (and/or the first setback weight 31 thereof) by an acceleration of the projectile 100 with respect to the launch bore 202 during a launch of the projectile 100. In addition, the releasing step may also comprise, as shown in FIG. 9, sensing the inner wall 201 of the launch bore 202 with a proximity safety device 40 (and/or the bore rider pin 44 included as part of the proximity safety device 40, in some embodiments). According to such method embodiments, the releasing step may further comprise determining that the inner wall 201 is no longer sensed by the proximity safety device 40, after disengaging the first acceleration device 30 from the arming switch 10 (see FIG. 9); and disengaging the proximity safety device 40 (as shown in FIG. 10, for example) from the arming switch 10 after the determining step so as to allow the arming switch 10 to be moved to the second position such that the explosive train is capable of being armed when the projectile 100 is launched from the launch bore 202. As described herein with respect to some SA system 1 embodiments of the present invention, the proximity safety device 40 may comprise a bore rider pin 44 slidably disposed in a first pin channel 20A defined by the system housing 20. According to such embodiments, the method may further comprise (as shown in FIG. 9): contacting the inner wall 201 of the launch bore 202 with a first end 44A of the bore rider pin 44 when the projectile 100 is disposed within the launch bore 202; and engaging a second end 45 of the bore rider pin 44 with the arming switch 10 (and/or a locking channel 10C defined therein) so as to normally retain the arming switch 10 in the first position, when the projectile 100 is disposed within the launch bore 202. In such method embodiments, the method may further comprise biasing the bore rider pin 44 towards the inner wall 201 of the launch bore 202 using a biasing element 41 (such as a coil spring, for example) operably engaged between the system housing 20 and the bore rider pin 44 (and/or a spring tab 46 extending outward from the bore rider pin 44), such that when the projectile 100 is launched from the launch bore 202 (see FIG. 2, for example), the first end 44A of the bore rider pin 44 (see FIG. 10, for example) becomes unconstrained, such that the second end 45 of the bore rider pin 44 disengages the arming switch 10 (and/or a locking channel 10C defined therein) such that the arming switch 10 is capable of being moved to the second position and consequently such that the explosive train is capable of being armed.

As described herein with respect to some SA system 1 embodiments of the present invention, the proximity safety device 40 and the operation thereof may be coupled with an optical sensor 43 configured to be capable of transmitting a signal to initiate an arming sequence of the projectile 100 (i.e. by initiating the movement of an actuator device 50 to actuate the arming switch 10 (see FIG. 4D, for example), and/or by initiating the generation of arming signals that may be transmitted to the detonator 11 carried by the arming switch 10). According to such embodiments, as shown generally in FIG. 3, the proximity safety device 40 (and/or a bore rider pin 44 included as a component of the proximity safety device 40) may comprise a tab 42 configured to normally cover an optical sensor 43 in communication with the detonator 11 and/or the actuator device 50 (as described further herein). The optical sensor 43 may be operably engaged with the system housing 20 (and/or a circuit board 80 disposed therein). Thus, in such embodiments, the method may further comprise steps for moving the tab 42 so as to uncover the optical sensor 43 (and/or remove a substantially opaque barrier between a light source and a light detection device that may be included as part of the optical sensor 43) when the projectile 100 is launched from the launch bore 202 (see FIGS. 9 and 10, sequentially showing the movement of the tab 42 relative to the optical sensor 43 as the projectile 100 exits the launch bore 202). Thus, once the tab 42 is removed, the optical sensor 43 is capable of transmitting the signal to the actuator device 50 and/or the detonator 11 for initiating the arming and/or actuation of the explosive train carried by the projectile 100. Furthermore, the method may further comprise transmitting the signal from the optical sensor 43 to the actuator device 50 and/or detonator 11 such that the actuator device 50 is capable of moving the arming switch 10 from the first position (see, for example, FIG. 10) to the second (armed) position (see FIG. 11) at a selected time after the projectile 100 is launched from the launch bore 202. Furthermore, the method embodiments of the present invention may also comprise, moving the arming switch 10 from the first (safe) position to the second (armed) position using an actuator device 50 operably engaged between the system housing 20 and the arming switch 10 (see, for example, FIG. 4D (showing the contact between a piston 51 of the actuator device 50 and a bearing surface 10B defined by a cutaway of the arming switch 10) in response to a signal received by the actuator device 50.

As described herein with respect to SA system 1 embodiments including a second acceleration safety device 60 (configured to be capable of disabling a normally short-circuited electrical pathway between a control device and a portion of the explosive train (and/or the actuator device 50), for example), the providing step may further comprise providing a wiring assembly 62 (see, for example, FIGS. 7, 12 and 13) operably engaged with the system housing 20 and configured to be capable of short circuiting a signal suitable for actuating the explosive train and/or initiating movement of the actuator device 50. According to such embodiments, the method may further comprise disabling the wiring assembly 62 (i.e. by cutting one or more wires, as shown in FIG. 7 and/or by disengaging a slider switch 66B from the contacts on the wiring assembly 62 (as shown in FIGS. 12 and 13)), in response to the acceleration force, using a second acceleration safety device 60 operably engaged with the system housing 20, such that the signal is capable of being transmitted to the actuator device 50 and/or some portion of the explosive train carried by the projectile 100. Following the disabling step, such method embodiments may further comprise a step for transmitting the signal to the actuator device 50 such that the actuator device 50 is capable of moving the arming switch 10 from the first (safe) position (see FIG. 10) to the second (armed) position (see FIG. 11. In some embodiments, the transmitting step may further comprise transmitting a signal from a control device carried by the system housing 20 (and/or a circuit board 80 disposed therein), wherein the signal is configured to be capable of actuating at least a portion of the explosive train (such as the detonator 11 carried by the arming switch 10).

Many modifications and other embodiments of the system and method set forth herein will come to mind to one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.