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Title:
SAFETY INDEXING DEVICE FOR LAUNCHER FIRING MECHANISMS
United States Patent 3786716
Abstract:
The firing mechanism of a multishot rocket launcher comprises a shaft jouled for rotation within the launcher case and for longitudinal displacement between an extended and a telescoped position respective thereto. A firing pin mechanism carried by the shaft for longitudinal displacement therewith successively retracts and releases a plurality of firing pins responsive to rotation of a rotary cam on the shaft by a trigger mechanism. Displacement of the shaft to the telescoped position disconnects the trigger mechanism therefrom and engages the shaft with a safety guide tube thereby indexing the firing pin mechanism so as to be safely uncocked and securing it against actuation after being indexed.


Inventors:
WILSON D
Application Number:
05/314491
Publication Date:
01/22/1974
Filing Date:
12/12/1972
Assignee:
The United States of America as represented by the Secretary of the Army (Washington, DC)
Primary Class:
Other Classes:
89/1.41, 89/1.813, 89/9
International Classes:
F41A19/21; (IPC1-7): F41F3/04
Field of Search:
89/1R,1L,9,1
View Patent Images:
Primary Examiner:
Engle, Samuel W.
Attorney, Agent or Firm:
Kelly Jr., Edward Berl Herbert Arnold Albert J. E.
Parent Case Data:


The above-identified patent application is a continuation-in-part of applicant's copending previously filed patent application, Ser. No. 158,792, filed 1 July 1971, now abandoned.
Claims:
I claim

1. In a firearm having a case, a shaft journaled in said case for rotary and longitudinal displacement relative thereto, a firing pin mechanism mounted to said shaft for longitudinal displacement therewith between an extended position and a telescoped position relative to the said case, and a trigger mechanism including a trigger pivotally mounted to said case and a first means for converting pivotal displacement of said trigger to rotation of said shaft for actuating said firing pin mechanism, the improvement comprising the addition of safety indexing means slidably disposed on said shaft and arranged to disconnect said first means from said firing pin mechanism, and means to secure said firing pin mechanism against rotation, both said safety indexing means and said securing means being responsive to longitudinal displacement of said firing pin mechanism to said telescoped position within said case.

2. The invention as defined in claim 1 wherein said first means includes a ratchet sleeve journaled for rotation on said shaft, a drum journaled for rotation on said ratchet sleeve, a lanyard connecting said trigger to said drum for converting pivotal displacement of said trigger to rotation thereof, pawl means for transmitting rotation of said drum in one direction to said ratchet sleeve, at least one key extending radially from said shaft, said ratchet sleeve comprising a plurality of notches extending thereinto from one end thereof, each of said notches being adapted for receiving said key responsive to disposition of said shaft in the extended position for transmitting rotation of said ratchet sleeve to said shaft, and wherein said safety indexing means comprises a safety guide tube secured within said case against displacement relative thereto, and said safety guide tube being provided with a plurality of slots extending therealong from one end thereof, each of said slots being disposed for receiving said key in response to said shaft being disposed in the telescoped position to index said shaft so that said firing pin mechanism is safely uncocked and to secure said shaft against actuation after being so indexed.

3. The invention as defined in claim 2 wherein said safety guide tube is located in said case in axial alignment with said ratchet sleeve to thereby receive said tube therein in response to said firing pin mechanism being disposed in the telescoped position, and wherein said slotted end of said safety guide tube is disposed adjacent the notched end of said ratchet sleeve and is spaced therefrom a distance which is less than the cross-sectional dimension of said key to thereby prevent entrance thereof between said ratchet and said safety guide tube during displacement of said shaft between the extended and telescoped positions.

4. The invention as defined in claim 3 wherein each of said notches terminates in a niche disposed for receiving said key with a minimum of clearance and including a helical side for directing said key into said niche when pressed thereagainst.

5. The invention as defined in claim 4 wherein said firing pin mechanism comprises a plurality of spring biased firing pins and said safety guide tube slots are equal to the number of said firing pins and are each related to one thereof, and wherein each of said slots includes a triangular clearance having a helical edge for directing said key into the associated one of said slots responsive to said shaft being displaced to the telescoped position thereby indexing said shaft so that said firing pin mechanism is safely uncocked.

6. The invention as defined in claim 5 wherein said firing pin mechanism includes a rotary cam fixed to said shaft for rotation therewith, said rotary cam comprising a helical surface successively contactable with a follower on each of said firing pins for retraction thereof, and said helical surface terminating in a radial surface at a peak to thereby release said firing pins successively responsive to rotation of said shaft, and wherein each of said slots is disposed so that when said key is located therein said follower on the associated one of said firing pins is located past said peak of said rotary cam and in contact with said surface thereof.

Description:
BACKGROUND OF THE INVENTION

This invention relates to firing mechanisms for firearms and pertains more particularly to firing mechanisms for multishot launchers wherein a plurality of firing pins are successively retracted and released by a trigger displaced rotary cam.

A particular multishot rocket launcher is provided with a firing mechanism comprising a pivotal trigger and a cable lanyard which is pulled thereby and is connected to a drum for converting the pivot displacement of the trigger to rotary movement thereof. A shaft supports and drives a cam actuated firing pin mechanism which retracts and releases one of four firing pins responsive to 90° rotation of the shaft and which is also longitudinally displaceable with the shaft between an extended position and a telescoped position. In the telescoped position the shaft is secured against rotation respective to the launcher case and thereby, when the trigger is pulled, the cable lanyard becomes stretched to where pivotal displacement of the trigger cannot rotate the shaft 90° required for retraction and release of one of the firing pins. Consequently, the launcher fails to fire. Also, the firing pins are successively retracted and released to fire the associated rockets, by a rotary cam on the shaft which rotary cam acts against a pin follower on successive ones of the firing pins responsive to repeated pulls on the trigger. Because of this arrangement, when the trigger is partially pulled and the shaft is rotated thereby less than 90°, it is possible for the firing pin to be hung-up, cocked, on the peak of the rotary cam without the operator knowing of the dangerous situation whereby the cocked firing pin can be easily released to fire the associated rocket if the launcher should be suddenly jarred. This is a particularly dangerous situation if the launcher is telescoped for carrying when the cocked firing pin is accidentally released.

SUMMARY OF THE INVENTION

It is a principal object of this invention to provide for such a firing mechanism the improvement whereby the trigger mechanism is disconnected from the firing pin mechanism when the drive shaft, with the firing pin mechanism carried thereby, are in their telescoped, safe position so that the trigger may be freely displaced with no strain being placed upon the lanyard if the trigger should be inadvertently pulled.

It is a further object of this invention to provide for such a firing mechanism the improvement whereby, when the firing pin mechanism is disconnected from the trigger mechanism by location of the shaft in its telescoped position, the shaft has engagement with a safety guide tube which serves to index the rotary cam of the firing pin mechanism so that the peak thereof is positively positioned away from the pin follower on any of the firing pins, and to secure the rotary cam in the indexed position.

The above stated objects are achieved by providing on the shaft operatively supporting the firing pin mechanism a radially extending key which, when the shaft is in the operative extended position, engages one of a plurality of notches formed in one end of a ratchet sleeve thereby connecting the trigger to the firing pin mechanism. When the shaft is in the inoperative telescoped position, the key is disengaged from the notches, thereby disconnecting the trigger from the firing pin mechanism so as to be freely displaceable, and is received by one of a plurality of slots extending along a safety guide tube to thereby index the shaft so that the firing pin mechanism is safely uncocked and is secured against actuation.

Further objects and advantages of the invention will be apparent from the following specification and the accompanying drawings which are for the purpose of illustration only.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational side view of the launcher showing the clip in the extended position and with the launcher case partially broken away to illustrate certain features of the launcher and particularly the relationship of the trigger mechanism and the safety guide tube;

FIG. 2 is an elevational view similar to FIG. 1 but showing the clip telescoped into the launcher case;

FIG. 3 is an enlarged longitudinal view of the trigger mechanism and the safety guide tube which is partially broken away and cross-sectioned;

FIG. 4 is a cross-sectional view taken along line 4--4 of FIG. 3;

FIG. 5 is an enlarged cross-sectional view taken along line 5--5 of FIG. 2;

FIG. 6 is an exploded perspective view of the firing pin and trigger mechanisms and the safety guide tube;

FIG. 7 is an exploded view, in perspective, of the rocket clip; and

FIG. 8 is an enlarged view of the manifold, partly broken away and sectioned to show an igniter and flash tube train for firing one of the rockets.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Shown in the drawing is a multishot rocket launcher 12 adapted for firing four rocket assemblies 13 semi-automatically from a clip 14 which is replaceably mounted to the launcher as hereinafter described. Clip 14 secures together a cluster 16 of four rocket assemblies 13 adjacent to their respective bases and in two-by-two arrangement, by a star-shaped manifold 18.

Launcher 12 comprises a case 20 with four symmetrically arranged and longitudinally disposed firing tubes 22 each of which slidingly receives one of the rocket assemblies 13 of the cluster 16 when loaded to the launcher and which initially guides the rocket portion of each assembly in its flight after being ignited in the clip. A central hole 24 of cruciform configuration is formed between tubes 22, as shown in FIG. 5, and such hole receives manifold 18 when clip 14 is loaded into launcher 12 as hereinafter described.

A shaft 25 is axially located in hole 24 for rotation and for limited longitudinal displacement between a forward telescoped position and a rearward extended position. Formed around shaft 25 adjacent to the rear end thereof is an annular groove 26 which is releasably engageable by a retainer 27 on manifold 18 to thereby secure clip 14 to shaft 25 for longitudinal displacement therewith between the telescoped position, shown in FIG. 2, and the extended position, shown in FIG. 1 while permitting relative rotating movement. A handle 15 is provided on manifold 18 to facilitate loading as well as movement between the extended and telescoped positions.

Located on shaft 25 forwardly of groove 26 is a firing pin mechanism 28, such as is fully disclosed in the U. S. Patent of Frederick P. Reed entitled "Firing Mechanism for a Multishot Launcher," U.S. Pat. No. 3,641,868. Firing pin mechanism 28 includes a housing 30 which is attached to manifold 18 and which is essentially cylindrical with four arcuate channels 32, having approximately the same radius as the inside of the firing tubes 22, longitudinally formed along the outside of the housing in symmetrical arrangement, as shown in FIGS. 5 and 6. Thus, housing 30 has a cross-sectional configuration similar to that of hole 24 so that the housing is slidingly received thereby when moved with shaft 25 to the telescoped position. When shaft 25 is in its extended position, housing 30 is located outside case 20, and is secured in alignment therewith by manifold 18 as each of the rocket clusters 16 thereof is received by both one of the firing tubes 22 and one of the channels 32.

Located in housing 30 between each pair of the channels 32, as shown in FIG. 5, is a firing pin 34 for igniting the associated one of the rockets in the assembly 13. Each firing pin 34 is retracted against the bias of a cooperating spring 36 by a rotary cam 38 which is fixed to shaft 25 and which includes a helical surface 40 that is successively contactable with a follower 41 which extends from each of the firing pins to effect consecutive retraction thereof responsive to 90° rotation of the shaft. Helical surface 40 is sharply terminated, as shown in FIG. 6, by surface 42 which extends radially from shaft 25 to form a peak 43 so that when the shaft is rotated 90° the firing pin 34 is retracted by contact of the helical surface with follower 41 and then is released to impact by bias of the respective spring 36 against the igniter 79 of the related rocket, for ignition thereof, when peak 43 is moved past such follower. Manifold 18 is provided with four cavities 81 for receiving igniters 79 which are oriented in alignment with respective ones of the firing pins 34. Each one of the rockets 13 is provided at its rearward end with a flash tube 80 the free end of which is inserted into a radially disposed aperture 82 to an extent to contact with its respective igniter, as shown particularly in FIG. 8.

Shaft 25 is rotated 90° at a time for cyclic activation of one of the firing pins 34 by a trigger mechanism 44 which includes a trigger 46 pivotally mounted on case 20 and a lanyard 48. Lanyard 48 comprises a cable section 50 wound at one end to a drum 51, thereby converting pivotal movement of trigger 46 in the one plane to rotational movement in a plane 90° to the trigger plane, and the drum is journaled for rotation on a ratchet sleeve 52 which, in turn, is journaled for rotation on shaft 25. Four recesses 54 are formed 90° apart around ratchet sleeve 52 and each of the recesses is provided with a longitudinal surface 56 which is contactable by a pawl 58 pivotally mounted to a drum 51, for transmitting rotational pull by trigger 46 to ratchet sleeve 52. Located in a housing 53, as shown in FIG. 4, is an annular coiled spring 60 which is compressed by pin 55 in drum 51 when the drum is rotated by pull on trigger 46 and which applies the stored energy back to the drum for counter-rotation thereof to its initial position when pressure on the trigger is released.

Rotation of ratchet sleeve 52 is transferred to shaft 25 by the engagement of a pair of cylindrical keys 62, extending diametrically from the shaft, with a pair of the eight triangular notches 64 that extend rearwardly into the ratchet sleeve from the front end thereof. Each of notches 64 is terminated by a niche 66 which receives one of the keys 62 with a minimum of clearance and each notch comprises a longitudinal side 68 that forms one side of the niche and a helical side 70 that leads to the other side thereof from the next one of the notches. Thus, when keys 62 contact a pair of the helical sides 70 and are pressed thereagainst they are guided thereby into the related ones of the niches 66 to connect ratchet sleeve 52 to shaft 25 for transmitting positive rotation of the ratchet sleeve thereto. Firing pin mechanism 28 in housing 30 is indexed in an uncocked position and is ready to fire when trigger 46 is released to its normal position and drum 51 is located by spring 60 in its initial position; pawl 58 is located in contact with surface 56 of one of the recesses 54; one of the pin followers 41 is in contact with surface 42 of rotary cam 38; and the firing pin mechanism is pulled to the extended position so that keys 62 are located in a pair of niches 66.

Firing mechanism 28 is secured in the uncocked position so as to be in a safe condition by a safety indexing device comprising a safety guide tube 71, which is located in hole 24 forwardly of ratchet sleeve 52 and is secured against displacement relative to case 20. Tube 71 is axially aligned with shaft 25, as shown in FIG. 3, so that the front portion of the shaft is receivable therewithin during displacement to the telescoped position. Four slots 72, spaced 90° apart, extend longitudinally in tube 71 from the rear end thereof to form two pair combinations each pair receiving the keys 62 when shaft 25 is actuated to the telescoped position. Thus, rotation of the shaft is blocked to secure firing pin mechanism 28 against actuation. Each of the pairs of slots 72 is associated with a firing pin 34 and the slots are located so that when keys 62 are received by one of the four pair combinations rotary cam 38 is indexed to where follower 41 of the associated firing pin is located past peak 43 and is in contact with surface 42. To assure reception of keys 62 by slots 72 and to index rotary cam 38 in the uncocked position, the rear end of each of the slots is enlarged by a triangular clearance 74 which is formed by the extension of one side of the slot and a helical edge 76 leading from the rear end of tube 71 to the other side of the slot for guiding the keys thereinto. The rear end of tube 71 is spaced from the front end of ratchet sleeve 52 a distance which is less than the diameter of keys 62 so that they cannot be caught therebetween during displacement of shaft 25.

OPERATION

When launcher 12 is loaded with a clip 14 and is to be carried in a safe condition, the clip with firing pin mechanism 28 is telescoped into case 20, as shown in FIG. 2, whereby shaft 25 is displaced forwardly to locate keys 62 in one pair of the slots 72. Thus, rotary cam 38 of firing pin mechanism 28 is indexed so that one of the pin followers 41 is in contact with surface 42 and the other followers are, therefore, located away from peak 43 to thereby assure that none of the firing pins are cocked. Firing pin mechanism 28 is also blocked against rotation from the indexed position to prevent action of the rotary cam 38 against follower 41 of any of the firing pins 34. However, drum 51 is free to rotate when trigger 46 is pulled as ratchet sleeve 52 is disconnected from shaft 25.

Launcher 12 is readied for firing by pulling handle 15 rearwardly which pulls shaft 25 to the extended position. As shaft 25 is moved to the extended position, keys 62 move along slots 72 and enter the pair of notches 64 which are in alignment therewith. Any misalignment is corrected by contact of keys 62 with helical sides 70 which direct the keys into niches 66, as shown in FIG. 3. With keys 62 located within niches 6, trigger mechanism 44 is connected to firing pin mechanism 28 with one of the followers 41 located in contact with surface 42 of rotary cam 38. When trigger 46 is pulled, drum 51 is rotated and the rotation thereof is transmitted to ratchet sleeve 52 and therefrom to shaft 25 through the engagement of keys 62 with niches 66. Thus, cam 38 is moved against pin follower 41 of one of the four firing pins 34 via surface 42 for retraction and release thereof against the igniter of the related rocket 13. In response to firing the igniter, the free end of the respective flash tube 80 is ignited, which then sends a flash to the rocket 13 with which it is connected thereby firing the rocket for propulsion from the launcher.

I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.