Abstract:
An assist for drawing a bowstring of a compound bow to a position close to the standard draw position is described. The assist is a crutch that is inserted into a crutch mount that is affixed to the riser of the bow. The crutch allows the archer to place the bow on a support surface and to pull the bowstring up onto the crutch. When the archer is ready to shoot an arrow, he pulls the bowstring back from the crutch. The head of the crutch rotates into a vertical position, providing an unencumbered path for the arrow.

Description:
BACKGROUND INFORMATION 
     1. Field of the Invention 
     The invention relates to archery bows. More specifically, the invention relates to an accessory to facilitate drawing the bowstring to the standard draw position. 
     2. Discussion of the Prior Art 
     In a compound bow, the amount of force required to pull the bowstring to its standard draw is high during the first part of the draw and is reduced after a certain point. This reduction in force is referred to as a “let off”. Despite the let off, a person must exert a significant amount of force to pull the bowstring to its draw point. This makes it difficult or impossible for persons who do not have the sufficient strength to complete the draw to engage in archery activities. This is particularly the case with older bows, which do not as much of a “let off.” 
     What is needed is an assist for pulling the bowstring on a compound bow to the desired draw. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention is a crutch that assists a user in pulling a bowstring on a compound bow to its standard draw without having to hold the bow in the operative position, i.e., holding the bow with outstretched arms in a vertical orientation. 
     A mount for the crutch is affixed to the riser of the bow and the distal end of the crutch is inserted into or onto the mount. The body of the crutch extends in the direction of the archer, bringing the proximal end of the crutch to a position that corresponds to the position of the bowstring at the standard draw position. The horizontal position of the crutch is just above or beneath the level of the arrow shelf. 
     To use the crutch, the archer places the bow on some firm surface, i.e., the ground, a low stool, on top of one foot, or some other support surface, inserts the distal end of the crutch into the crutch mount, and uses a foot to hold the bow against the support surface while simultaneously drawing the bowstring with one or two hands onto the proximal end of the crutch. The bowstring now remains in the draw position on the crutch, without the user having to hold the bowstring. The user can now bring the bow to the operative position and place the arrow at the nocking point on the string, all without having to exert the energy to hold the bowstring in place. Once the user is ready to shoot the arrow, he or she pulls the bowstring away from the crutch. The crutch now automatically rotates to a position that does not impede the release of the arrow. 
     The use of the crutch also allows a third person to assist an archer by pulling the bowstring onto the crutch for the archer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. The drawings are not drawn to scale. 
         FIG. 1  is a side elevation view of the crutch according to the invention. 
         FIG. 2  is a front elevation view of the crutch in a relaxed state. 
         FIG. 3  is an outer side elevation view of the crutch mount. 
         FIG. 4  is a rear elevation view of the crutch mount. 
         FIG. 5  is an inner side elevation of the crutch mount. 
         FIG. 6  shows the crutch assembled on the riser of a compound bow. 
         FIG. 7  illustrates the crutch inserted into the mount, with the bowstring pulled over the crutch head. 
         FIG. 8  shows the position of the crutch head when the bowstring has been pulled away from it. 
         FIG. 9  illustrates a second embodiment of the crutch device according to the invention. 
         FIG. 10  is a perspective view of the crutch head. 
         FIG. 11  is a side plan view of the crutch head, showing the bowstring holder. 
         FIG. 12  illustrates a compound bow with a string guide, with the crutch device of  FIG. 9  mounted on the string guide. 
         FIG. 13  is a schematic illustration, front view, of the riser portion of a compound bow, illustrating the crutch device mounted on the string guide. 
         FIG. 14  is the same view as  FIG. 13 , with the bowstring pulled onto the crutch head, showing the crutch head in its tensioned position. 
         FIG. 15  is the same view as  FIG. 13 , but without the bowstring pulled onto the crutch device, showing the crutch device in its home position. 
         FIG. 16  illustrates a bowstring safety device that may be used with any embodiment of the crutch device according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention will now be described more fully in detail with reference to the accompanying drawings, in which the preferred embodiments of the invention are shown. The drawings are not to scale, but are sufficient to illustrate the various elements of the inventive subject matter. The invention should not, however, be construed as limited to the embodiment set forth herein; rather, the embodiment is provided so that this disclosure will be complete and will fully convey the scope of the invention to those skilled in the art. 
     Note: references to place locations of elements are in reference to the archer holding a bow. Thus, “proximal” is closer to the archer than “distal”, “front” is a face or surface that faces the archer, etc. 
       FIGS. 1 and 2  illustrate a crutch device  10  according to the invention, for use with a compound bow  100 . The crutch device  10  comprises a crutch  20  and a crutch mount  30 . The crutch  20  includes a crutch body  22  that has a crutch head  24  at a proximal end  20 A and an insertion end  28  at a distal end  20 B. The crutch head  24  is rotatably mounted on the crutch body  22  by some suitable means  26  that fixes the crutch head  24  a specific distance from the insertion end  28 , yet allows the head to rotate about the body axis. In the embodiment shown, the means  26  is a pair of bushings  26 A, each secured in place on the crutch body  22  with a set screw  26 B. It is understood that other suitable means for rotatably securing the crutch head  24  to the crutch body  22  may be used. 
     The crutch head  24  is constructed asymmetrically, as shown in  FIG. 1 . A first end  24 A is shorter, and thus, lighter in weight, than a second end  24 B. The imbalance in weight ensures that the crutch head  24  will immediately rotate to a relaxed, i.e., vertical position, as shown in  FIG. 1 , unless some force is applied to it to hold it in a horizontal position. 
       FIGS. 3-5  illustrate a crutch mount  30  that is mounted on a riser  110  of the bow  100  and receives the insertion end  28  of the crutch  20 . The crutch mount  30  has a mounting plate  32  with mounting holes  34  and a receiving head  36 . The mounting holes in the plate  32  are dimensioned so as to align with mounting holes that are provided in the conventional compound bow  100  for mounting the quiver or the string guide, thereby eliminating the need to bore additional holes into the bow. In the embodiment shown, the receiving head  36  has two sleeves  38 , a proximal sleeve  38 A and a distal sleeve  38 B. The proximal sleeve  38 A has a through-bore  39  that is dimensioned to allow the insertion end  28  of the crutch body  20  to pass through it and be supported by it. The distal sleeve  38 B has a slight recess for retaining and supporting the insertion end  28  of the crutch body. 
       FIG. 6  is a partial sketch of a conventional compound bow, illustrating the crutch mount  30  affixed to the riser  110  of the bow. Only the upper limb and riser are illustrated in this sketch. The crutch body  22  is shown inserted into the mount  30 , just above the arrow rest AR. The compound bow  100  has a bowstring  120  that is stretched around, two pulleys, one at each end of a limb. The central stretch of the bowstring that is pulled by the archer is designated as  120 ; the two end stretches that are attached to the pulleys are designated  120 ′ and  120 ″.  FIGS. 7 and 8  are very rudimentary sketches that show the crutch mount  30  mounted on the riser, with all other components that are typically mounted on the riser removed, for purposes of illustration.  FIG. 7  illustrates the horizontal orientation of the crutch head  24  when the bowstring  120  is tensioned over the crutch head.  FIG. 8  illustrates the vertical orientation of the crutch head  24 , when the string is pulled away from the head and force of gravity has pulled the heavier side of the crutch head  24 B downward, bringing the crutch head  20  to a vertical position. 
       FIGS. 9-11  illustrate a second embodiment of the crutch device  11  according to the invention and  FIG. 12  illustrates a compound bow  100  with rod  101  for a string guide, with the crutch device  11  mounted on the string guide  101 . Compound bows can be very complex instruments, with many accessories mounted on them.  FIG. 10  is a very simplified illustration of the compound bow, and the bow itself is shown for the purposes only of illustrating the cable or string guide  101  that is mounted on the riser  110 . This crutch device  11  is a simplified version that is mounted directly on the string guide  101  and comprises the crutch  20  with the proximal end  20 A and the distal end  20 B, and a spring-biased crutch head  25  mounted toward the proximal end. A mounting means  27  is provided for mounting the device  11  on the string guide. In this embodiment, the mounting means  27  includes one or more collars  27 A that are adjustably mounted on the crutch body  22 . Attached to the collar  27 A is a threaded rod  27 B with a bushing  27 C. The bushing  27 C has a set screw for tightening it to a desired position on the string guide rod  101 .  FIG. 10  shows the crutch device  11  mounted on the string guide rod  101 . 
     The spring-biased crutch head  25  has bowstring holders  25 A for holding the bowstring in a loaded position. A collar  258  is mounted on the proximal end of the crutch body  22  and fixed in place. A position-biasing means  25 C is captured by the collar  25 B and coupled with the crutch head  25 , so as to bias the crutch head to a home position. The crutch head  25  in this embodiment is slidably mounted on the crutch body  22  and is held there by the biasing means  25 C. 
       FIGS. 13-15  are schematic illustrations of the position of the crutch device  11  on the compound bow.  FIG. 13  shows the crutch body  20  mounted to the string guide  101 . For purposes of illustration, the crutch head  25  is not shown.  FIG. 14  illustrates the position of the crutch head  25  when tensioned by the bowstring  120  and  FIG. 15  the home position of the crutch head  25 . As shown, the untensioned crutch head  25  is rotated to its home position, with the bowstring holders  25 A facing away from the bowstring. The tension device  25 C ensures that the crutch head  25 , when the bowstring is released from the crutch head, immediately moves out of the way of the arrow. 
     Use of the Crutch: 
     If the crutch device is the first embodiment, then the crutch mount  30  has previously been affixed to the riser  110  of the bow and the archer inserts the crutch body  22  into the crutch mount  30 . If the device is the second embodiment, the crutch body has previously been mounted to the string guide. The archer places the compound bow on some support surface, with the front face of the bow facing upward. Placing a foot over the bow, to hold it against the support surface, the archer then pulls the bowstring  120  with one or two hands upward and onto the crutch head  24  or  25 . The archer can now pick up the bow and resume the normal archer&#39;s stance, ready to shoot. When the bowstring is pulled away from the crutch head  24 , the head immediately rotates into the home position, allowing the archer to shoot the arrow without the crutch head obstructing the path of the arrow. 
     A bowstring safety device  40  may be used with the crutch device  10  or  11 . The safety device  40  has a bore  42  that is dimensioned to fit over the proximal end  20 A of the crutch body  22  and a plastic deflector or shield  44 , such as is shown in  FIG. 16 , that prevents the bowstring from moving to the outside of the crutch head. 
     As with any device or tool that is tensioned or loaded for use, it is advisable to release the tension when the device is not in use. This is the case with the bow also, The crutch should not remain loaded for an extended period of time, because the load will eventually weaken the limbs. 
     It is understood that the embodiments described herein are merely illustrative of the present invention. Variations in the construction of the crutch may be contemplated by one skilled in the art without limiting the intended scope of the invention herein disclosed and as defined by the following claims.