US20110168146A1

US20110168146A1 - Archery Release Device with Bowtie Cam

Info

Publication number: US20110168146A1
Application number: US13/006,267
Authority: US
Inventors: Andrew Deceuster
Original assignee: Utah State University USU
Current assignee: Utah State University USU
Priority date: 2010-01-14
Filing date: 2011-01-13
Publication date: 2011-07-14

Abstract

A triggerless back tension archery release device to assist archers in pulling a bow string to a fully drawn position and then releasing the bow string to fire an arrow. The surprise release timing is dependent upon a bowtie cam which is a bowtie shaped member containing various size corner edge notches. The bowtie cam may be rotated and then fixed at the desired orientation for pulling the arrow to the fully drawn position. The depth of the notch in the bowtie cam determines the surprise release timing. The bowtie cam is designed with a notch on each of the four corners. The bowtie cam may be reoriented to place any one of the four corner edge notches in the active position thus providing various degrees of flexibility for the surprise release timing.

Description

RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 61/294,884, filed Jan. 14, 2010, and titled “Back Tension Archery Release Device with Bowtie Cam” which is incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to a triggerless back tension archery release device for use with a bow string and more specifically, a four position bowtie cam in a triggerless back tension release device.

BACKGROUND OF THE INVENTION

A back tension release device is one of several types of archery aids used by archers to assist in pulling a bow string to a fully drawn position and then releasing the bow string to fire the arrow. Nervousness and tension during the shooting motion, and the anticipated release of the bow string, can result in a temporary loss of control, flinching, or an uncontrollable reflex movement, known as target panic, which can result in the arrow missing its target. Target panic is the inability of an archer to accurately aim and execute a controlled shot at the precise instant he/she intends to shoot.
A back tension release device allows for a surprise shot, thus eliminating the negative effects of target panic and improving shot consistency. When the exact timing of a shot is controlled by an archer, there is a higher probability of an inaccurate shot. A back tension device produces a surprise shot in which the exact timing of the release of the arrow is not controlled or known to the archer. The arrow release is initiated after the bow string is pulled to a fully drawn position by the rotation of the back tension device in the archer's hand. A slight increase in the tension at full draw coupled with a slight rotation of the archery release will cause the back tension device to release the string.
Existing back tension release devices can contain a half moon or D-shape cam that can be adjusted to regulate the timing of the release. A clicker half moon or D-shape cam has a notch machined into the shooting edge of the cam. The notch causes an audible click which notifies the archer that the release is ready to fire, thus providing a reference before the arrow is released. This allows the archer to advance his/her draw immediately to the click and then settle into his/her shot routine for a surprise release. The timing from the click to the release can be changed by using a cam with a different depth notch and the amount of travel to reach the click is adjusted by rotating the cam.
The standard half moon or D-shape cam design has two locations where notches can be machined. A new cam design is desired in which a greater number of notches can be machined to provide greater timing flexibility in a back tension release device while maintaining the ability to rotate the cam to adjust the amount of travel to reach the click.

SUMMARY OF THE INVENTION

The present invention is a triggerless back tension archery release aid system containing a novel bowtie cam which provides archers with an option of four surprise release times. The bowstring release aid is held in the hand of the archer and is used to draw back the bowstring. The bowstring release aid is shaped and fitted to accommodate the fingers on the hand while gripping the release. The bowstring is attached to the bowstring release aid with a sear hook which rotates and releases the bowstring upon proper force and angle.
The surprise release time may be changed by the adjustment of the bowtie cam. The orientation of the bowtie cam may be selected by the archer, thus positioning the desired corner notch in the active position for the surprise release. The unique geometry of the bowtie cam allows for the archer to select any one of the four possible corner notches for the surprise release, in addition to rotating the cam for pull back adjustment.

BRIEF DESCRIPTION OF THE DRAWINGS

Understanding that drawings depict only certain preferred embodiments of the invention and are therefore not to be considered limiting of its scope, the preferred embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

FIG. 1 a is a drawing of the back tension archery release device.

FIG. 1 b shows the bowtie cam and other components attached to the stem.

FIG. 2 a is an isometric view of the bowtie cam.

FIG. 2 b is a drawing showing the bowtie cam with different notch sizes.

DETAILED DESCRIPTION OF SELECTED EMBODIMENTS

In the following description, numerous specific details are provided for a thorough understanding of specific preferred embodiments. However, those skilled in the art will recognize that embodiments can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In some cases, well-known structures, materials, or operations are not shown or described in detail in order to avoid obscuring aspects of the preferred embodiments. Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in a variety of alternative embodiments. Thus, the following more detailed description of the embodiments of the present invention, as represented in the drawings, is not intended to limit the scope of the invention, but is merely representative of the various embodiments of the invention.
The triggerless back tension release device 10, shown in FIG. 1 a, comprises a finger grip handle 11 with a stem 12 extending from between a first finger groove 13 and a second finger groove 14. The finger grip handle 11 may be configured with four finger grooves 13, 14, 15, 16 as shown in FIG. 1. In other embodiments, the finger grip handle 11 may be configured with three finger grooves 13, 14, 15, or two finger grooves 13, 14. A bowtie cam 17 and a sear 20 are connected to the end of the stem 12 with a linkage member 19.
FIG. 1 b shows the bowtie cam 17 is connected to the stem 12 and the linkage member 19 by the bowtie pin 18. The sear 20 is connected to the opposite end of the linkage member 19 by the sear pin 21. The sear 20 is a crescent shaped member with the bow string hook 22 at the end opposite the bowtie cam 17 and a corner edge 24 at the end near the bowtie cam 17. When the bow string is in the bow string hook 22 at the beginning of the pull back, the corner edge 24 of the sear 20 is in contact with the sliding surface 23 of the bowtie cam 17. As the bow string is pulled back and the tension increases, the corner edge 24 slides along the sliding surface 23 of the bowtie cam 17 and comes to rest as it clicks into the bowtie corner edge notch 25. The bowtie cam 17 is shown in FIGS. 2 a and 2 b with the corner edge notch 25 at the end of the sliding surface 23. The click indicates to the archer that the surprise release is imminent. Referring back to FIG. 1 a, as the pull back tension is increased, a threshold level is reached upon which the sear corner 24 disengages from the bowtie notch 25 and the sear 20 freely pivots around the sear pin 21 releasing the bow string from the bow string hook 22.
The bowtie cam 17, shown in FIGS. 2 a and 2 b, controls the pull back and surprise release characteristics of the triggerless back tension archery release device. The bowtie cam 17 is shaped similar to a bowtie with a hole in the center. There are two curved side segments, also referred to as curved adjustment surfaces 29 on opposite sides of the hole. The center region of these curved side segments 29 is concentric with the hole and has a radius greater than the radius of the hole. There are two sliding surfaces 23 on opposite sides of the hole, above and below, which are concentric with the hole. These sliding surfaces 23 have a radius greater than the radius of the curved side segments 29.
The bowtie cam 17 is held in place by the bowtie pin 18 passing through the center of the bowtie cam 17, the stem 12, and the linkage member 19. The bowtie pin 18 allows the bowtie cam 17 to be rotated by the archer to a desired position or orientation relative to the stem 12, thus providing pull back adjustment for initiating the release. A screw or fastening mechanism (not shown) is tightened against the curved adjustment surface 29 of the bowtie cam 17 to secure it in place and keep it from rotating during a shot.
FIGS. 2 a and 2 b show corner edge notches 25, 26, 27, 28 cut from the corners of the bowtie cam 17. The size of each notch 25, 26, 27, 28, is related to the surprise release point. For different embodiments, the notches 25, 26, 27, 28 may be machined to various incremental depths, all the same depth, or a combination of equal and different depths. The bowtie cam 17 may even contain one or more corners without a notch. The geometry of the bowtie cam allows the archer to re-orient the bowtie cam 17 by loosening the screw or fastening mechanism and rotating the bowtie cam 17 to put a different notch in the active position against the sear 20. The bowtie pin 18 may be removed and the bowtie cam 17 turned and reinserted to put another notch in the active position. For example, referring to FIG. 2 b, if notch 25 is in the active position, the bowtie cam 17 may be rotated around the bowtie pin 18 to place notch 27 in the active position. Notch 28 may be moved to the active position by removing bowtie pin 18, removing the bowtie cam 17 from the stem 12 and linkage member 19, turning the bowtie cam 17 over and reinserting it into the stem 12 and replacing the bowtie pin 18. From this position notch 26 may be moved to the active position by simply rotating the bowtie cam 17. The unique geometry of the bowtie cam 17 in the triggerless back tension archery release device 10 allows for a range of adjustable pull back characteristics and up to four different surprise timing release options. With the same size notches, the archer may re-orient the bowtie cam when one notch wears out, thus keeping the same surprise timing and not having to replace the entire triggerless back tension archery release.
Without further elaboration, it is believed that one skilled in the art can use the preceding description to utilize the invention to its fullest extent. Therefore the examples and embodiments disclosed herein are to be construed as merely illustrative and not a limitation of the scope. It will be obvious to those skilled in the art that many changes may be made to the details of the above described embodiments without departing from the underlying principles of the invention.

Claims

1. A triggerless back tension archery release device comprising:

a finger grip handle including at least two finger grooves;

a stem attached to and extending away from said handle;

a bowtie shaped bowtie cam with a through hole in the center;

a linkage member;

a bowtie pin passing through said hole in said bowtie cam to fasten said bowtie cam to said stem and said linkage member; and

a sear having a bow string hook on one end and fastened to said linkage member with a sear pin, wherein increasing the tension on the bow string causes the rotation of said sear relative to said bowtie cam resulting in the bow string being released.

2. The device of claim 1 wherein said bowtie cam has two curved side segments, two curved sliding surfaces, and a notch in at least one corner edge.

3. The device of claim 2 wherein said bowtie cam can be re-oriented in said triggerless back tension archery release device to put a different said corner edge in the active position.

4. The device of claim 2 wherein the center regions of said curved side segments are concentric with said hole and have a radius greater than the radius of said hole.

5. The device of claim 4 wherein said sliding surfaces are concentric with said hole and have a radius greater than said radius of said curved side segments.

6. The device of claim 3 wherein said notches in said bowtie cam are different sizes.

7. The device of claim 3 wherein two said notches in said bowtie cam are equal sizes.

8. The device of claim 3 wherein three said notches in said bowtie cam are equal sizes.

9. The device of claim 3 wherein four said notches in said bowtie cam are equal sizes.

10. A cam for a triggerless back tension archery release device comprising:

a component in the shape of a bowtie with

a through hole in the center;

two curved side segments;

two curved sliding surfaces; and

a notch in at least one corner edge.

11. The cam of claim 10 wherein said curved side segments are on opposite sides of said hole and the center regions of said curved side segments are concentric with said hole and have a radius greater than the radius of said hole.

12. The cam of claim 11 wherein said sliding surfaces are on opposite sides of said hole and are concentric with said hole and have a radius greater than said radius of said curved side segments.

13. The cam of claim 10 wherein said notches are different sizes.

14. The cam of claim 10 wherein two said notches are equal sizes.

15. The cam of claim 10 wherein three said notches are equal sizes.

16. The cam of claim 10 wherein four said notches are equal sizes.