Abstract:
An accessory for an archery bow has a C-shaped forearm brace attached to the distal end of a support. The support can be supported on the bow. The brace extends arcuately around a forearm axis at least 180° in order to partially encompass a forearm. The support is mounted in an arcuate slot in the brace and extends outwardly, transverse to the forearm axis. The support can be adjusted to allow angular and linear translation of the forearm brace relative to an adjustment axis that is parallel to the forearm axis. The forearm brace is circumferentially repositionable along the support. The support may be a post with a bearing surface skewed relative to a plane perpendicular to the longitudinal axis. This post may have on opposite sides of the bearing surface, a pair of walls that straddle a peripheral portion of the forearm brace.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to training devices for an archery bow, and in particular, to devices for engaging the forearm of an archer. 
     2. Description of Related Art 
     An archery bow may have a substantial draw weight, that is, a substantial force required to pull the string back and fully flex the bow. This force can produce torques that change the aiming of the arrow in elevation and azimuth. Moreover, these torques will abruptly change direction at the moment the string is released to launch the arrow. For this reason, a certain amount of angular rotation of the bow can be expected and tolerated when the string is released. Specifically, when the string is released the bow normally tends to rotate in a vertical plane with its upper tip tilting forward. 
     Improved accuracy is achieved if the archer does not grip the bow too tightly. A tight grip tends to apply undesirable torques to the bow. In a recommended shooting method, the hand holding the bow is kept relatively open so the bow passes though the crook between the thumb and forefinger to balance primarily against the heel of the palm. This relatively open grip avoids manual torques that might tend to undesirably rotate the bow azimuthally or elevationally when aiming an arrow. Instead, the bow takes a balanced position that enhances accuracy. 
     Modern bows have threaded sockets for accepting a variety of accessories. For example, stabilizers in the form of cantilevered weights can be attached to the bow to balance it and to increase its moment of inertia, in order to reduce undesirable bow rotations and vibrations. Also, a string vibration arrester mounted on the bow has a rod terminating with a notched cradle for stopping a released string at a neutral position and preventing vibration. 
     With a compound bow the string is part of a cable system and is suspended between cams on opposite ends of the bow. When the string is pulled the cables are drawn over the cams to produce a mechanical advantage. A cable guard can be used to push the cables to the side to avoid interference with the bow string in the nock of the arrow. This cable guard can take the form of a rod screwed into a threaded socket on the bow and extending rearwardly. The affected cables can engage the guard either directly or through a slide mounted on the guard. 
     Any accessory attached to a bow must not interfere with the ease of use. Often, a bow must be quickly grasped and raised when hunting. A hunter does not have the time to manipulate accessories when a target suddenly comes within range. 
     See also U.S. Pat. Nos. 3,572,312; 3,599,621; 4,787,361; 4,836,177; 4,976,250; 5,137,008; 5,349,937; 5,464,002; 5,531,211; 5,853,000; 6,173,707; 7,748,369; and 7,954,175. 
     SUMMARY OF THE INVENTION 
     In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided an accessory for an archery bow. The device has a forearm brace and a support. The forearm brace extends arcuately around a forearm axis and sized to partially encompass a forearm. The support has a distal portion that is attached to the brace and extends away from the forearm axis. The support has a proximal portion contiguous with the distal portion. The proximal portion is adapted to be supported by the bow. 
     In accordance with another aspect of the invention, there is provided an accessory for an archery bow. The device has a support and a rigid, C-shaped forearm brace. The brace has an arcuate slot and an inside and an outside. The brace extends arcuately around a forearm axis at least 180°. The brace is sized to partially encompass a forearm. The support has a proximal portion contiguous with a distal portion. The distal portion is attached to the outside of the brace in the arcuate slot. The distal portion extends outwardly from the brace in a direction transverse to the forearm axis. The support is adjustable to allow angular and linear translation of the forearm brace relative to an adjustment axis that is parallel to the forearm axis. The proximal portion is adapted to be supported by the bow. The distal portion of the support is circumferentially repositionable along the outside of the forearm brace. The support includes a post having a longitudinal axis and a distal end. The post has on the distal end a bearing surface skewed relative to a plane perpendicular to the longitudinal axis. The post has on opposite sides of the bearing surface a pair of walls straddling a peripheral portion of the forearm brace. 
     By employing an accessory of the foregoing type, an archer can achieve improved accuracy. In a disclosed embodiment a C-shaped brace is supported on its periphery by a post. The post can be perpendicularly mounted on a rod that is, in turn, attached to a threaded socket on the back of the riser of the bow. This rod can be dedicated to supporting the brace or may be part of another accessory, such as a string vibration arrester or cable guard. 
     In this disclosed embodiment the C-shaped brace extends 240°, has beveled tips, and is sized to encircle an archer&#39;s forearm. This forearm brace is mounted in a channel at the distal end of the post. The floor of this channel is skewed so it does not lie in a plane transverse to the post axis. This skewing is designed to tip the brace closer to the archer&#39;s forearm. 
     The position of the disclosed brace can be adjusted. For example, the post supporting the brace can be shifted back and forth along the rod that is attached to the bow. Thus, the forearm brace can be moved closer to or farther from the archer&#39;s wrist. Also, the post can be angularly adjusted to raise and lower the forearm brace. In this embodiment post  12  is 2 inches (5 cm) long, but different lengths may be employed in other embodiments depending upon the bowl and the archer. Also, and some embodiments, the position of the forearm brace can be adjusted by choosing an appropriate post from a set of posts of different lengths. 
     In the disclosed embodiment, the forearm brace can be rotated relative to the post. Specifically, the brace will have a circumferentially extending slot. A screw will extend through the slot and into a threaded hole in the floor (bearing surface) of the channel at the distal end of the post. Thus, to the extent allowed by the slot, the forearm brace can be rotated and then secured in place by tightening the screw. Accordingly, the angular position of the brace can be adjusted so it extends, for example, from the nine o&#39;clock to five o&#39;clock position on the forearm (from the vantage point of the archer). 
     When adjusted appropriately, the forearm brace rests lightly atop the archer&#39;s forearm when the bow string is drawn and the bow grip is resting against the heel of the extended hand, between the thumb and forefinger. If the extended hand inappropriately squeezes the bow, it will tip forward, lifting the forearm brace. The lifting of the brace will give the archer an indication that the grip must be changed. 
     Once the string is released and the arrow launched, the bow will tend to tip forward. This natural tipping will be accommodated by the forearm brace which is sufficiently open to allow unimpeded lifting of the brace and rotation of the bow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above brief description as well as other objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of illustrative embodiments in accordance with the present invention when taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is an exploded view of an accessory in accordance with principles of the present invention; 
         FIG. 2  is an elevational view of the device of  FIG. 1 , assembled; 
         FIG. 3  is a side view of the device of  FIG. 2  shown embracing an archer&#39;s forearm; 
         FIG. 4  is a perspective view of the device of  FIG. 2  shown mounted on an archery bow; 
         FIG. 5  is a detailed view of the assembly of  FIG. 4  with portions of the bow broken away for illustrative purposes; and 
         FIG. 6  is a perspective view of a support that is an alternate to that shown in  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1 and 2 , archery bow  14  is shown with an accessory comprising forearm brace  10  mounted on support  12 . Brace  10  is C-shaped and extends from bevelled tip  10 A to bevelled tip  10 B. Brace  10  is shown with a cylindrical inside  10 D and with a cylindrical outside  10 C that extends 240° around forearm axis  16 , although a greater or smaller angular dimension may be employed in other embodiments. Starting approximately 15° from tip  10 A, arcuate slot  18  extends circumferentially 70°. Slot  18  runs from outside  10 C to inside  10 D. Recess  20  on inside  10 D encompasses slot  18 . 
     Support  12  is shown as a cylindrical post with a longitudinal axis  22 . The distal end of post  12  has a bearing surface  24  that is skewed approximately 7° from a plane that is perpendicular to longitudinal axis  22 . Surface  24  has central threaded hole  25  and is bordered on opposite sides by parallel walls  26 . Walls  26  form a channel sized to embrace forearm brace  10  at peripheral portion  10 E. The wall-to-wall space of the channel is 0.5 inch (1.3 cm) and its depth is ⅛ inch (3 mm) with post  12  having a diameter of ¾ inch (1.9 cm), although these dimensions can be different in different embodiments. 
     Screw  28  can be inserted through washer  30  and slot  18  before being threaded into hole  25 . As shown in  FIG. 2  washer  30  has a bevelled face pressing against recess  20 . The beveling of washer  30  accommodates the skewing of bearing surface  24 . Washer  30  can be either molded into the illustrated shape or can be made from an elastomeric material that deforms into this shape when compressed by screw  28 . 
     The proximal portion of post  12  has through bore  32  extending along adjustment axis  34 , which axis is perpendicular to walls  26  and axis  22 . In this specification support  12  is deemed divided into two contiguous portions, namely, a proximal portion containing bore  32  and a distal portion having the channel located between walls  26 . The border between the proximal and distal portions is somewhat arbitrary and may be considered a divison into half and half, one third and two thirds, etc. 
     Referring to  FIGS. 4 and 5 , bow  14  has a pair of limbs  38  bolted on opposite ends of riser  40 . Limbs  38  are bifurcated and rotatably support a pair of cams  42 A and  42 B mounted on axles  44 A and  44 B between the bifurcations. 
     Bow string  46  is routed around cam  42 A and is shown descending down as cable  46 A to attach through a split yoke to the ends of axle  44 B. Likewise, bow string  46  is routed around cam  42 B and is shown ascending as cable  46 B to attach through a split yoke to the ends of axle  44 A. Cable guard  48  is mounted in a threaded hole on the back of riser  40  above arrow rest  45 . Guard  48  presses cables  46 A and  46 B to the right to avoid interference with bow string  46 . 
     String vibration arrester  50  has a post  50 A that is mounted in a threaded hole in the back of riser  40  just below hand grip  52 . Clamp  50 B is mounted on the distal end of post  50 A and supports rod  50 C. Forked rubber implement  50 D is mounted on the distal end of rod  50 C and is shown straddling bow string  46  in  FIG. 4 . Arrester  50  and guard  48  are herein referred to as rearwardly extending bow accessories. 
     Rod  50 C is shown inserted through bore  32  of previously mentioned post  12 . Rod  50 C may be pulled out of clamp  50 B in order to insert the rod through bore  32 , before again clamping rod  50 C in clamp  50 B. Post  12  can linearly translate along the length of rod  50 C, as well as angularly translate around the rod, before being locked into place by tightening set screws  36 ,  37 A and  37 B against rod  50 C. Set screw  36  is screwed into the proximal end of post  12  through a treaded axial bore that reaches bore  32 . Set screws  37 A and  37 B are screwed into diametrically opposed, threaded radial bores (bore  39 A visible in  FIG. 1 ) that reach bore  32 . While three set screws are illustrated, some embodiments many employ one, two or another number of set screws. 
     To facilitate an understanding of the principles associated with the foregoing apparatus, its operation will be briefly described. An archer will grasp grip  52 , placing it between thumb T and forefinger I using a relatively open grip. At the same time, the archer&#39;s forearm F will be inserted into brace  10 . If brace  10  does not fit comfortably, various adjustments can be made. 
     To perform adjustments, set screws  36 ,  37 A and  37 B can be loosened to move brace  10  along rod  50 C and thus along the length of forearm F. Also, support  12  can be rotated about rod  50 C to change the elevation of brace  10 . In some embodiments a collection of alternate supports will be supplied that can be longer or shorter than support  12 . Accordingly, an archer can select a support having a length that positions brace  10  at a desired distance from rod  50 C. Alternatively, support  12  can be fabricated as a post within a larger hollow post so that the length of the support can be telescopically adjusted. 
       FIG. 3  shows brace  10  encircling forearm F for approximately 240°. Tip  10 A is shown located at the five o&#39;clock position and tip  10 B at the nine o&#39;clock position (viewed from the archer&#39;s vantage point). That orientation can be achieved by loosening screw  28  so it can be shifted in slot  18  in order to rotate brace  10 . It will be appreciated that other orientations may be desired. In some cases the orientation may be set to extend from eight o&#39;clock to four o&#39;clock; 10 o&#39;clock to six o&#39;clock, etc. In some embodiments, brace  10  may have an angular dimension smaller than 240°, for example, 180°, 200°, 220°, etc. Also in this embodiment, brace  10  has an inside diameter of 3.0 inches (7.6 cm) and an outside diameter of 4.0 inches (10 cm), although these dimensions may be varied depending upon the size of the archer&#39;s forearm F. 
     When screw  28  is tightened, outside  10 C is pressed against the skewed bearing surface  24 . Due to this skewing, forearm axis  16  is shifted away from longitudinal axis  22 , as shown in  FIG. 3 . This skewing is 30°±15° but can be different in other embodiments. This skewing provides the advantage of bringing the brace  10  closer to forearm F. The tilting of brace  10  caused by bearing surface  24  is accommodated by washer  30 , which is tapered at an angle to accommodate the skewing of the bearing surface. 
     In any event, brace  10  is positioned so that forearm F can be easily inserted into and removed from the brace. Ease of use can be very important when bow  14  must be quickly raised and fired by a hunter who is responding to the arrival of a target. 
     With string  46  drawn and arrow A nocked and placed in rest  45 , significant forces and torques will be applied to bow  14 . If an archer squeezes grip  52  too tightly, bow  14  will tend to rotate in a vertical plane with the top of the bow shifting forward. However, brace  10  is arranged to encompass the top of forearm F. This feature gives positive feedback to let an archer know whether an improper grip is causing rotation of bow  14 . The archer will notice such rotation because brace  10  will lift from forearm F. 
     When bow string  46  is released and arrow A is launched, bow  14  will naturally tend to rotate in a vertical plane with the top of the bow moving forward. Brace  10  is open and therefore accommodates this natural rotation. Basically, forearm F moves out of brace  10  as the brace moves upwardly due to rotation of bow  14 . 
     Referring to  FIG. 6 , alternate support  112  is shown. Components corresponding to that previously illustrated for the support of  FIG. 1  will bear the same reference numeral but increased by 100. Support  112  is shown as a solid rectangular prism with a V-shaped notch  154  at one end (in the proximal portion) and at the other end (in the contiguous, distal portion) a skewed bearing surface  124 . Surface  124  has central threaded hole  125  and is bordered on opposite sides by parallel walls  126  and  124 . Walls  26  form a channel sized to embrace forearm brace (brace  10  of  FIG. 1 ) at peripheral portion  10 E. 
     As before, the C-shaped brace (brace  10  of  FIG. 2 ) can be inserted between walls  126  to bear against surface  124 . The brace can be secured in place using the previously mentioned screw and washer (screw  28  and washer  30  of  FIG. 2 ). 
     In this embodiment, support  112  has a clamp  156  in the form of a rectangular block with a V-shaped notch  158  facing notch  154 . Clamp  156  can be secured to the body of support  112  by a pair of screws  160  that are inserted through bores  162  (only one visible in this view) before being screwed into threaded holes (not shown) in notch  154 . 
     Previously mentioned rod (rod  50 C of  FIG. 5 ) can be inserted between notches  154  and  158  with screws  160  loosely holding clamp  156  in place. Support  112  can then be adjusted linearly and angularly before being clamped onto the rod by tightening screws  160 . Notches  154  and  158  are oriented to keep the forearm axis of the brace parallel to the clamped rod. 
     Support  112  can be used to allow the same adjustments as previously described for the embodiment of  FIG. 1 . Accordingly, the brace can be positioned and used to assist an archer in the manner previously described. 
     It is appreciated that various modifications may be implemented with respect to the above described embodiments. While a compound bow is illustrated the present invention can be applied to various other types of bows. The dimensions can be adjusted to accommodate different bows and different archers. The disclosed support and brace can be made aluminum, steel, other metals, plastics, composite materials, etc. In some cases the brace may be flexible to yield and facilitate placing the forearm into and out of the brace. In some embodiments the inside of the brace may be padded for comfort. Also, the brace need not be circular and may be curved to ergonomically engage the forearm. Instead of using a skewed bearing surface, the support may be a rod that curves toward the forearm to bring the brace closer to the forearm. In some embodiments the support may be a flexible gooseneck or may incorporate one or more universal joints that allow spatial adjustment. The support joint may be configured as an encircling hook or as a claw with opposing teeth that fit into arcuate slots on the side of the brace. Alternatively, the brace may have an arcuate, external fin that slides in a narrow slot at the end of the support; or may have an external groove that straddles a rib at the end of the support. A support was shown using a separate V block to clamp to a rod, and likewise, similar structure can be used on the opposite end of the support to clamp to the brace. 
     Obviously, many 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 invention may be practiced otherwise than as specifically described.