Telescopic flick knife
United States Patent 3895441

A hand held knife ejector having a power spring to eject the blade and a scroll spring for blade control and recapture. The blade is held in place against a compression power spring by a simple latching device. Upon release of the latching device, the power spring drives the blade outward. A scroll spring is connected to the blade to return it to a cocking position.

Application Number:
Publication Date:
Filing Date:
Primary Class:
Other Classes:
International Classes:
B26B1/08; F41B13/00; (IPC1-7): B26B1/08
Field of Search:
30/162 46
View Patent Images:
US Patent References:
3515112PROJECTILE FIRING GUN TOY1970-06-02Baginski
3456376SPRING-LOADED SPEARING GIG1969-07-22Chappell
3158099Flare igniting and supporting device1964-11-24Dzvonik
2618885Helix projecting toy gun1952-11-25Tigrett
1828812Splice for elastic webbing1931-10-27David
1504073Disappearing bayonet1924-08-05Moore

Primary Examiner:
Stahl, Robert F.
Attorney, Agent or Firm:
Sciascia, Watson Sivertson R. S. T. W.
What is claimed is

1. A hand held knife ejector which comprises:

2. The device of claim 1 wherein the scroll spring is generally cylindrical, the power spring lying totally within the scroll spring and the knife blade extending partially into the scroll spring.

3. An ejector comprising:

4. The ejector of claim 3 wherein the scroll spring has an inner coil and an outer coil, and the outer coil is connected to the abutment and the inner coil is connected to said device.

5. The ejector of claim 4 wherein said biasing means is a compression spring having one of its ends connected to the abutment and its other end acting upon said device when said device is in said first cocked position.

6. The ejector of claim 5 wherein said compression spring is mounted within said scroll spring.

7. The ejector of claim 6 wherein said second latching means comprises:

8. The ejector of claim 7 wherein said cocking means comprises:

9. The ejector of claim 8 wherein said moving means comprises:

10. The ejector of claim 9 wherein said holding means comprises:

11. The ejector of claim 10 wherein the urging means comprises a biasing spring mounted between the abutment and the trigger bar.

12. The ejector of claim 11 wherein the device ejected includes an incapacitating element.

13. The ejector of claim 9 wherein the device includes a knife blade.

14. The ejector of claim 9 wherein flexible pins connect the device to the inner coil of said scroll spring.

15. The ejector of claim 8 wherein said second latching means comprises:

16. The ejector of claim 15 wherein said cocking means comprises:

17. The ejector of claim 16 wherein said moving means comprises:

18. The ejector of claim 17 further comprising a trigger connected to said trigger bar and extending out of said casing whereby depressing said trigger disengages the second and third latches.

19. The ejector of claim 18 wherein said device includes a knife blade.


The present invention relates generally to knife blade ejectors and more particularly to a hand held device capable of ejecting and recapturing a knife blade.

Many devices have been developed which are capable of ejecting a knife blade, spear, etc. Few of these devices, however, are capable of retrieving the ejected implement for a quick redeployment. The present invention provides a device having this capability.

A casing small enough to be held in the hand, has positioned within it a knife blade or scalpel. A compression spring is used to eject the blade out of the casing, and a simple trigger and latching mechanism holds the spring in a compressed state until deployment is desired. A scroll spring is attached to the blade and acts to both orient the blade in its flight and to recapture the blade and return it such that recompression of the power spring is easily effected.


An object of the present invention is the provision of a hand held weapon which may be effective at distances beyond arms length.

Another object is to provide a hand held weapon which may be used repeatedly as necessary.

Other objects, advantages, and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.


FIG. 1 shows an internal view of the knife ejector of the present invention.

FIG. 2 shows the knife ejector of the present invention in the deployed configuration.

FIG. 3 shows a cross-sectional view taken along the line 3--3 in FIG. 1.

FIG. 4 shows a cross-sectional view taken along the line 4--4 in FIG. 1.

FIG. 5 shows a cross-sectional view taken along the line 5--5 in FIG. 2.

FIG. 6 shows a cross-sectional view of a slightly modified casing as it would appear when taken along the line 4--4 in FIG. 1.


FIG. 1, which illustrates a preferred embodiment of the present invention, shows a casing 11 enclosing a knife blade 12. The knife blade 12 has a cutting portion 13 and a rearwardly extending portion 14. Attached to the knife blade extending portion 14 is a hook type latch 16 which cooperates with a second hook type latch 17. When these latches, 16 and 17, are connected as shown in FIG. 1, they operate to keep a power spring 19 compressed between a rear bulkhead 20 which is rigidly affixed to casing 11 and retaining pins 21. The retaining pins 21 are connected between the knife blade extending portion 14 and the inner coil of a scroll spring 23.

The latching member 17 is formed on the end of a latching bar 25 which extends through the bulkhead 20 to the rear of the casing 11 where it joins and forms a unitary assembly with trigger bar 27. A cocking fork 28 extends from outside the casing 11 and partially surrounds an enlarged portion 29 of the trigger-latching bar assembly (see FIG. 3). A tension spring 31 is attached to the cocking fork 28 by means of members 32 and the other end of the tension spring 31 is connected to the bulkhead 20 by means of similar attaching members 33. The attaching members 33 also maintain the compression spring 19 in position against the bulkhead 20. The outer coil of the scroll spring 23 is fixed at one end to the bulkhead 20 by any suitable means.

The cocking fork 28 is pivotally connected at 35 about an extending member 36 which is rigidly attached to the casing 11 at the point 37. From the pivot point 35 the cocking fork 28 extends beyond the casing 11 to pivotally connect with a cocking bar 39. The other end of the cocking bar 39 is pivotally connected with a cover latch 40. The cover latch 40 is rigidly attached to the cover 41 such that movement of one causes a corresponding movement in the other. The cover latch 40 and latching bar 26 are provided with latches 42 and 43 generally similar in form and operation to the latches 16 and 17. A trigger bar biasing spring 44 is used to hold the entire latching assembly in the position shown in FIG. 1 until the trigger bar is displaced through pressure on the trigger 45.

In operation, beginning with the device configured as shown in FIG. 1 (with the power spring 19 in compression and the tension spring 31 in tension), the trigger 45 is depressed against the biasing spring 44. This causes the latching bars 25 and 26 to move relative to their cooperating members and release the latching members 42 and 43. With the restraints on the cover latch 40 thus removed, the tension of the spring 31, acting on the cocking fork 28 and through the cocking bar 39, causes the cover latch 40 to pivot and spring open the cover 41. Simultaneously, the latches 16 and 17 will separate thus freeing the knife blade 12 for ejection by the compressing spring 19. This is accomplished by the compression spring 19 acting upon the retaining pin 21. As the knife blade 12 moves under the force of the compression spring 19 the scroll spring 23 is caused to extend from its normally cylindrical configuration (as shown in FIG. 1). During the travel of the knife blade 12 the connection to the scroll spring keeps the blade and its point properly oriented in space. The connecting pins 21 are designed to wrap around the extending portion 14 (see FIG. 5) upon extension of the scroll spring 23.

Upon full extension of the scroll spring 23 (a distance of 6 feet, for example) the spring will recoil itself and return the knife blade to the inside of the casing 11.

It should be further noted that upon actuation, movement of the cocking bar 39 rearward by the action of tension spring 31 also moves the unitary trigger-latching bar assembly 25, 26 and 27 in a forward direction. Tension spring 31 in effect pulls the lower portion of cocking fork 28 forward. Cocking fork 28 is affixed to the unitary trigger-latching assembly by pin 51. Thus, as bar 28 pivots about pin 35 upon actuation of the device latching bars 25, 26 and 27 will move forwardly. Upon return of the scroll spring the unitary trigger latching bar assembly is oriented such that latch 17 may be pulled back to catch the latch 16 and compress the power spring 19. This recocking action may be accomplished by merely closing cover 41. Further movement of cover 41 will mate the latches 42 and 43 and complete the latching operation. A safety mechanism represented by pin 50 may be employed to prevent inadvertant actuation of the cocked device.

As an alternative design, the casing 11 can be formed as shown in FIG. 6 to enclose the latching bar 39. Moreover, the knife may be replaced by an explosive, incendiary, poisonous or incapacitating device. Obviously, many other modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described.