Adjustable compound leverage bowstring release

Claims

What is claimed is:

1. A compound leverage bowstring release which may be held in the hand of an archer, comprising:

(a) a housing assembly having an outer contour to be grasped by the hand and a slot for receiving a bowstring;

(b) a latch cam which is pivotally mounted to the housing assembly, the latch cam including a lever portion and a latching portion having a drive wall against which the bowstring pushes when placed in the slot to pivot the latch cam from an open position to a latched position, and a retaining wall which retains the bowstring within the slot when the latch cam is in a latched position, the lever portion pivoting through a lever pathway when the latch cam pivots between the open and latched positions;

(c) a trigger cam which is pivotally mounted to the housing assembly, the trigger cam including a smooth wall which is a smooth continuous curvilinear even surface over which the lever portion always slides smoothly from engagement to disengagement without passing over corners and other impediments, and a grip portion which can be pressed by the archer's hand to pivot the trigger cam from a release position to at least one locking position where the smooth wall intersects the lever pathway of the latch cam lever portion to prevent the latch cam from pivoting from the latched position to the open position, wherein one locking position is a hand-held locking position in which the latch cam lever portion imposes a torque which tends to pivot the trigger cam toward its release position, said torque being counteracted by the archer's hand pressing the grip portion such that when the archer releases his pressure on the grip portion, the trigger cam can pivot so that the latch cam lever portion can pivot the smooth wall out of the lever pathway, thereby allowing the latch cam to pivot fully to the open position.

2. The bowstring release of claim 1 further including a return spring which biases the latch cam to the open position.

3. The bowstring release of claim 1 further including a spring which biases the trigger cam to the release position.

4. The bowstring release of claim 1 wherein the latching portion of the latch cam forms a notch with the drive wall and the retaining wall.

5. The bowstring release of claim 1 wherein the smooth wall is an obstacle which prevents the latch cam lever portion tip from passing directly between a pivotal axis of the trigger cam and the smooth wall, the latch cam lever portion therefore being able to abut and press against only a passive portion of the smooth wall to impose a torque which tends to pivot the trigger cam toward its release position, which torque can be counteracted by the archer's hand pressing the trigger cam grip portion, so that the only trigger cam locking position is the hand-held locking position, the adjustable bowstring release therefore being operable in only a passive manner.

6. The bowstring release of claim 1 wherein the latch cam lever portion is too short to pass directly between a pivotal axis of the trigger cam and the smooth wall, the latch cam lever portion therefore being able to abut and press against only a passive portion of the smooth wall to impose a torque which tends to pivot the trigger cam toward its release position, which torque can be counteracted by the archer's hand pressing the trigger cam grip portion, so that the only trigger cam locking position is the hand-held locking position, the adjustable bowstring release therefore being operable in only a passive manner.

7. The bowstring release of claim 1 further including means for adjusting the locking position of the trigger cam.

8. A compound leverage bowstring release which may be held in the hand of an archer, comprising:

(a) a housing assembly having an outer contour to be grasped by the hand and a slot for receiving a bowstring;

(b) a latch cam which is pivotally mounted to the housing assembly, the latch cam including a lever portion and a latching portion having a drive wall against which the bowstring pushes when placed in the slot to pivot the latch cam from an open position to a latched position, and a retaining wall which retains the bowstring within the slot when the latch cam is in a latched position, the lever portion pivoting through a lever pathway when the latch cam pivots between the open and latched positions;

(c) a trigger cam which is pivotally mounted to the housing assembly, the trigger cam including a smooth wall, and a grip portion which can be pressed by the archer's hand to pivot the trigger cam from a release position to at least one locking position where the smooth wall intersects the lever pathway of the latch cam lever portion to prevent the latch cam from pivoting from the latched position to the open position, wherein one locking position is a hand-held locking position in which the latch cam lever portion imposes a torque which tends to pivot the trigger cam toward its release position, said torque being counteracted by the archer's hand pressing the grip portion such that when the archer releases his pressure on the grip portion, the trigger cam can pivot so that the latch cam lever portion can pivot the smooth wall out of the lever pathway, thereby allowing the latch cam to pivot fully to the open position; and

(d) means for adjusting the locking position of the trigger cam comprising interior surfaces of the trigger cam which form an elongated groove therethrough having a first end and a second end, and a threaded bore which extends longitudinally with respect to the groove from an exterior surface of the trigger cam to a first end of the groove; an adjusting screw within the bore which turns to extend a selected distance into the groove; and a peg which extends from the housing assembly into the groove to prevent the trigger cam when in its release position from pivoting beyond where the peg abuts against the second end of the groove, and to prevent the trigger cam when in a locking position from pivoting beyond where the peg abuts against the adjusting screw.

9. The bowstring release of claim 8 wherein the trigger cam further includes a push release portion which when pushed imposes a torque which pivots the trigger cam toward its release position; and wherein the smooth wall is offset from a pivotal axis of the trigger cam away from a pivotal axis of the latch cam and includes an active portion; and wherein the latch cam lever portion is of length such that a tip of the lever portion can pass directly between the smooth wall and the pivotal axis of the trigger cam when the trigger cam is in its release position, so that the latch cam lever portion can abut against the active portion of the smooth wall to impose a torque on the trigger cam which maintains the trigger cam in a locking position so that the trigger cam has an additional locking position which is a lever-held locking position where the locking cam is pivoted from this lever-held locking position in an active manner by pressing the push release portion of the trigger cam.

10. The bowstring release of claim 9 wherein the adjustable screw can be turned to a position where the peg abuts against the screw when the trigger cam is yet in a hand-held locking position to prevent the trigger cam from being pivoted into a lever-held locking position so that the adjustable bowstring release can be adjusted to be operable in only a passive manner.

11. The bowstring release of claim 9 wherein the trigger cam includes two spool portions projecting axially outward which each are pivotably registered in a corresponding cavity in the housing assembly to pivotally mount the trigger cam within the housing assembly, the spool portions extending forwardly of the smooth wall so that the smooth wall faces toward the trigger cam pivotal axis.

12. A passive compound leverage bowstring release which may be held in the hand of an archer, comprising:

(a) a housing assembly having an outer contour to be grasped by the hand and a slot for receiving a bowstring;

(b) a latch cam which is pivotally mounted to the housing assembly, the latch cam including a lever portion and a latching portion having a driving wall against which the bowstring pushes when placed in the slot to pivot the latch cam from an open position to a latched position, and a retaining wall which retains the bowstring within the slot when the latch cam is in a latched position, the lever portion pivoting through a lever pathway when the latch cam pivots between the open and latched positions; and

(c) a trigger cam which is pivotally mounted to the housing assembly, the trigger cam including a smooth wall with a passive portion, the smooth wall being a smooth continuous curvilinear even surface over which the lever portion always slides smoothly from engagement to disengagement without passing over corners and other impediments, and a grip portion which can be pressed by the archer's hand to pivot the trigger cam from a release position to a hand-held locking position where the smooth wall passive portion intersects the lever pathway of the latch cam lever portion to prevent the latch cam from pivoting from the latched position to the open position, wherein the latch cam lever portion is able to abut and press against only the passive portion of the smooth wall to thereby impose a torque which tends to pivot the trigger cam toward its release position, which torque can be counteracted by the archer's hand pressing the trigger cam grip portion, so that when the archer releases his pressure on the grip portion, the trigger cam is free to pivot so that the latch cam lever portion can press against and pivot the smooth wall out of the lever pathway, thereby allowing the latch cam to pivot fully to the open position.

13. The bowstring release of claim 12 further including a return spring which biases the latch cam to the open position.

14. The bowstring release of claim 12 further including a spring which biases the trigger cam to the release position.

15. The bowstring release of claim 12 wherein the latching portion of the latch cam forms a notch with the drive wall and the retaining wall.

16. The bowstring release of claim 12 the smooth wall is an obstacle which prevents the latch cam lever portion tip from passing directly between a pivotal axis of the trigger cam and the smooth wall so that the latch cam lever portion is therefore able to abut and press against only a passive portion of the smooth wall.

17. The bowstring release of claim 12 wherein the latch cam lever portion is too short to pass directly between a pivotal axis of the trigger cam and the smooth wall, so that the latch cam lever portion is therefore able to abut and press against only a passive portion of the smooth wall.

18. The bowstring release of claim 12 further including means for adjusting the locking position of the trigger cam.

19. A passive compound leverage bowstring release which may be held in the hand of an archer, comprising:

(a) a housing assembly having an outer contour to be grasped by the hand and a slot for receiving a bowstring;

(b) a latch cam which is pivotally mounted to the housing assembly, the latch cam including a lever portion and a latching portion having a driving wall against which the bowstring pushes when placed in the slot to pivot the latch cam from an open position to a latched position, and a retaining wall which retains the bowstring within the slot when the latch cam is in a latched position, the lever portion pivoting through a lever pathway when the latch cam pivots between the open and latched positions;

(c) a trigger cam which is pivotally mounted to the housing assembly, the trigger cam including a smooth wall with a passive portion, and a grip portion which can be pressed by the archer's hand to pivot the trigger cam from a release position to a hand-held locking position where the smooth wall passive portion intersects the lever pathway of the latch cam lever portion to prevent the latch cam from pivoting from the latched position to the open position, wherein the latch cam lever portion is able to abut and press against only the passive portion of the smooth wall to thereby impose a torque which tends to pivot the trigger cam toward its release position, which torque can be counteracted by the archer's hand pressing the trigger cam grip portion, so that when the archer releases his pressure on the grip portion, the trigger cam is free to pivot so that the latch cam lever portion can press against and pivot the smooth wall out of the lever pathway, thereby allowing the latch cam to pivot fully to the open position; and

(d) means for adjusting the locking position of the trigger cam, wherein the locking position adjusting means comprises interior surfaces of the trigger cam which form an elongated groove therethrough having a first end and a second end, and a threaded bore which extends longitudinally with respect to the groove from an exterior surface of the trigger cam to the first end of the groove; an adjusting screw within the bore which turns to extend a selected distance into the groove; and a peg which extends from the housing assembly into the groove to prevent the trigger cam when in its release position from pivoting beyond where the peg abuts against the second end of the groove, and to prevent the trigger cam when in a locking position from pivoting beyond where the peg abuts against the adjusting screw.

20. A passive-active compound leverage bowstring release which may be held in the hand of an archer, comprising:

(a) a housing assembly having an outer contour to be grasped by the hand and a slot for receiving a bowstring;

(b) a latch cam which is pivotally mounted to the housing assembly, the latch cam including a lever portion and a latching portion having a drive wall against which the bowstring pushes when placed in the slot to pivot the latch cam from an open position to a latched position, and a retaining wall which retains the bowstring within the slot when the latch cam is in a latched position, the lever portion pivoting through a lever pathway when the latch cam pivots between the open and latched positions; and

(c) a trigger cam which is pivotally mounted to the housing assembly, the trigger cam including a smooth wall which is offset from a pivotal axis of the trigger cam away from a pivotal axis of the latch cam and which has a passive portion and an active portion; a grip portion which can be pressed by the archer's hand to pivot the trigger cam from a release position to a hand-held locking position and a lever-held locking position, the smooth wall intersecting the lever pathway of the latch cam lever portion when the trigger cam is in one of these locking positions to prevent the latch cam from pivoting from the latched position to the open position; and a push release portion which when pressed pivots the trigger cam toward its release position;

wherein when the latch cam is in a latched position and the trigger cam is in the hand-held locking position, the latch cam lever portion imposes a torque which tends to pivot the trigger cam toward its release position, said torque being counteracted by the archer's hand pressing the grip portion, the archer's release of his pressure on the grip portion freeing the trigger cam to pivot so that the latch cam lever portion can press against and pivot the smooth wall out of the lever pathway, thereby allowing the latch cam to pivot fully to the open position; and

wherein the trigger cam is mounted within the housing assembly in relation to the latch cam so that a tip of the trigger cam lever portion can pass directly between the smooth wall and the pivotal axis of the trigger cam when the trigger cam is in its release position, so that when the trigger cam is in the lever-held locking position the latch cam lever position can abut against the active portion of the smooth wall to impose a torque which maintains the trigger cam in a locking position so that the trigger cam is pivoted from this lever-held locking position in an active manner by the archer pressing the push release portion of the trigger cam.

21. The passive-active bowstring release of claim 20 wherein the trigger cam includes two spool portions projecting axially outward which each are pivotably registered in a corresponding cavity in the housing assembly to pivotally mount the trigger cam within the housing assembly, the spool portions extending forwardly of the smooth wall so that the smooth wall faces toward the trigger cam pivotal axis.

22. The passive-active bowstring release of claim 20 further including a return spring which biases the latch cam to the open position.

23. The passive-active bowstring release of claim 20 wherein the latching portion of the latch cam forms a notch with the drive wall and the retaining wall.

24. The passive-active bowstring release of claim 20 further including means for adjusting the locking position of the trigger cam.

25. The passive-active bowstring release of claim 24 wherein the locking position adjusting means comprises interior surfaces of the trigger cam which form an elongated groove therethrough having a first end and a second end, and a threaded bore which extends longitudinally with respect to the groove from an exterior surface of the trigger cam to the first end of the groove; an adjusting screw within the bore which turns to extend a selected distance into the groove; and a peg which extends from the housing assembly into the groove to prevent the trigger cam when in its release position from pivoting beyond where the peg abuts against the second end of the groove, and to prevent the trigger cam when in a locking position from pivoting beyond where the peg abuts against the adjusting screw.

26. The passive-active bowstring release of claim 25 wherein the adjusting screw can be turned to an extended position where the peg abuts against the screw when the trigger cam is yet in a hand-held locking position to prevent the trigger cam from being pivoted into a lever-held locking position so that the adjustable bowstring release can be adjusted to be operable in only a passive manner.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the sport of archery and more particularly to devices and accessories which are used to hold and to release the bowstring.

2. Description of the Prior Art

In the usual manual shooting of a bow and arrow, the bowstring and the arrow are pulled back by the ends of the fingers of one hand of the archer, an operation that requires considerable muscular strength in the archer's fingers. The difficulty encountered in holding the bowstring often results in erratic release of the string by the archer, and a resultant loss of accuracy.

Various devices have been developed which allow the archer to pull back the bowstring by pulling on a bowstring release device with the ends of the fingers of the hand. Depending on the device, the release of the bowstring may be accomplished by pulling a trigger which is provided on the device, or by releasing the trigger. U.S. Pat. No. 4,170,216 to Wilson discloses a bowstring release mechanism having a latching cam which holds the bowstring, and a trigger cam which prevents the latching cam from rotating to release the bowstring until the trigger cam is rotated by the archer's moving the trigger cam by pressing the trigger arm. A bowstring trigger release mechanism having a latching cam, actuator cam, and a plunger which is used to press against and rotate the actuator cam to thereby release the latching cam and bowstring is disclosed in the U.S. Pat. No. 4,009,703 to Cunningham, Sr. Both the Wilson and Cunningham, Sr. bowstring release mechanisms allow for only an active release of the bowstring by the archer's pulling a trigger. U.S. Pat. No. 4,232,649 to Allen et al. discloses a bowstring trigger release which also incorporates a double-cam type mechanism requiring active release. However, the entire trigger actuating device must be in total engagement before the bowstring may be held by the device.

A passive bowstring release mechanism which utilizes a single cam having a lever which is restrained by the hand of the archer when the bowstring is held in the latching portion of the cam is disclosed in U.S. Pat. No. 4,424,791 to Muehleisen. Since the Muehleisen device has only a single cam, the entire force of pulling on the bowstring must be provided by the ends of the fingers of the hand. U.S. Pat. No. 4,539,968 to Garvison discloses a bowstring release device with a double-cam mechanism which operates so that the bowstring may be released either passively by the archer releasing the trigger, or actively by the archer pulling the trigger. The Garvison device has a trigger cam and a latch cam which have complimentary detents which engage to hold the latch cam in its bowstring-engaging position. When the Garvison bowstring release device is used in its passive release mode, a spring moves the trigger cam so that the latch cam is snapped from a detent in the trigger cam when the archer releases the trigger cam. When used in its active release mode, the archer moves the trigger cam so that the latch cam is snapped from a detent in the trigger cam.

SUMMARY OF THE INVENTION

The present invention provides an improved, adjustable compound leverage bowstring release which may be held in the hand of an archer. The bowstring release includes a housing assembly having an outer contour to be grasped by the hand and a slot for receiving a bowstring, a latch cam which is pivotally mounted to the housing assembly, and a trigger cam which also is pivotally mounted to the housing assembly. The latch cam includes a lever portion and a latching portion having a wall against which the bowstring pushes when placed in the slot to pivot the latch cam from an open position to a latched position. The latching portion also has a retaining wall which retains the bowstring within the slot when the latch cam is in a latched position. The lever portion pivots through a lever pathway when the latch cam pivots between the open and latched positions.

The trigger cam includes a smooth wall, and a grip portion which can be pressed by the archer's hand to pivot the trigger cam from a release position to at least one locking position where the smooth wall intersects the lever pathway of the latch cam lever portion to prevent the latch cam from pivoting from the latched position to the open position. One locking position is a hand-held locking position in which the latch cam lever portion imposes a torque upon the trigger cam which tends to pivot the trigger cam toward its release position. This torque is counteracted by the archer's hand pressing the grip portion of the trigger cam. When the archer no longer presses the grip portion, the trigger cam is free to pivot so that the latch cam lever portion pivots the smooth wall out of its lever pathway. With the smooth wall out of the way, the latch cam is free to pivot fully to the open position. The torque which the latch cam lever portion imposes on the trigger cam renders the use of springs to bias the trigger cam unnecessary. The trigger cam may have an additional locking position called the lever-held locking position, from which the locking cam is pivoted from to its release position in an active manner by pressing a push release portion of the trigger cam. In such an embodiment, the smooth wall is off-set from a pivotal access of the trigger cam away from the pivotal access of the latch cam. The latch cam lever portion in such a case must be of length such that a tip of the lever portion can pass between the smooth wall and the pivotal axis of the trigger cam when the trigger cam is in its release position, so that the latch cam lever portion can abut against an active portion of the smooth wall to impose a torque on the trigger cam which maintains the trigger cam in the lever-held locking position until the archer imposes a counteracting torque by pressing the push release portion of the trigger cam to pivot the trigger cam toward its release position. Preferably, the compound leverage bowstring release includes means for adjusting the locking position of the trigger cam which restricts how far the trigger cam may rotate away from its release position. The trigger cam may be adjusted so that it is only able to pivot to its hand-held locking position, and not to its lever-held locking position. Alternatively, the adjustable compound leverage bowstring may be constructed so that it is operable in only a passive release manner. In such a case, the latch cam trigger portion tip would press against only a passive portion of the smooth wall on the trigger cam when the trigger cam is in its locking position.

The adjustable compound leverage bowstring release allows an archer to pull back a bowstring by pulling on the housing assembly with the entire hand of the archer, instead of pulling the bowstring with the ends of the fingers. The provision of both a latch cam and trigger cam within the bowstring release allows the bowstring to be held without the entire force of the pulling on the bowstring being transmitted through the cams to the fingers of the archer. Instead, much of the force which resists the pivoting of the latch cam to release the bowstring is provided by the trigger cam with its smooth wall which prevents the pivoting of the latch cam. Furthermore, as the trigger cam moves toward its release position, the latch cam lever portion sweeps across the smooth wall of the trigger cam until the smooth wall is completely out of the lever pathway. As such, the latch cam lever portion does not encounter any notches, detents, or corner portions from which it must be released. The release of the latch cam to its open position is therefore accomplished in a smooth continuous manner without the roughness or jerks that might otherwise occur.

Further objects, features, and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a perspective view of an adjustable compound leverage bowstring release in accordance with the present invention.

FIG. 2 is an exploded perspective view of the first adjustable compound leverage bowstring release of FIG. 1.

FIG. 3 is a top plan view of a fragmentary portion of the bowstring release of FIG. 1 with the cover plate removed and the bowstring release cocked with the trigger cam in its hand-held locking position.

FIG. 4 is a top plan view of a fragmentary portion of the bowstring release of FIG. 1 with the cover plate removed showing the release of the bowstring.

FIG. 5 is a top plan view of a fragmentary portion of the bowstring release of FIG. 1 with the cover plate removed and showing the bowstring release cocked with the trigger cam in its lever-held locking position.

FIG. 6 is a perspective view of another adjustable compound leverage bowstring release in accordance with the present invention.

FIG. 7 is a top plan view of a fragmentary portion of the bowstring release device of FIG. 6 with the cover plate removed showing the bowstring release cocked with the latch cam locked against the trigger cam.

FIG. 8 is a top plan view of a fragmentary portion of the bowstring release of FIG. 6 with the cover plate removed showing the release of the bowstring.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the drawings, a first preferred embodiment of an adjustable compound leverage bowstring release is shown generally at 10 in FIG. 1. FIG. 2 shows a fragmentary portion of the bowstring release in an exploded perspective view. The release 10 includes a housing assembly 11, a latch cam 12, and a trigger cam 13 which both are pivotally mounted to the housing assembly 11 as best shown in FIG. 3. The cover plate 14 is removed in FIGS. 3-5, but shown in FIGS. 1-2. The bowstring release 10 may also include a wrist cord 18 which wraps around the archer's wrist.

The housing assembly 11 has an outer contour as shown in FIG. 1 which is formed to be grasped by the hand of an archer. The housing assembly has a slot 15 which is formed for receiving a bowstring 16. The latch cam 12 is pivotally mounted to the housing assembly 11 by means of the pin 17, and may be biased to its open position shown in FIG. 4 by the return spring 19. The latch cam 12 includes a lever portion 20 and a latching portion 21. The latching portion 21 has a notch 23 which forms a drive wall 24 against which the bowstring 16 pushes when placed in a slot 15 to pivot the latch cam 12 from an open position to a latched position, and a retaining wall 25 which retains the bowstring 16 within the slot 15 when the latch cam 12 is in its latched position. The latch cam lever portion 20 with tip 26 is able to pivot between the bumpers 27 and 28 and pivots through a lever pathway when the latch cam 12 pivots between its open and latched positions. The latch cam 12 is shown in its open position in FIG. 4, and in its latched positions in FIGS. 3 and 5. The return spring 19 is really only necessary to bias the latch cam 12 to its open position when a bowstring 16 has not already been received into the notch 23. At that time, the latch cam 12 should be biased to its open position, so that it is able to receive the bowstring 16. Once a bowstring 16 is received in the notch 23 and the latch cam is pivoted to is latched position, the archer's pulling of the bowstring 16 with the bowstring release 10 will cause the latch cam 12 to be biased to its open position. The latch cam 12 is prevented from