Abstract:
A crossbow de-tensioning apparatus includes, in an embodiment, a de-tensioning device configured to be coupled to a crossbow. The de-tensioning apparatus also includes at least one hook operatively coupled to the de-tensioning device. The at least one hook is configured to be hooked onto a bowstring of the crossbow.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation application of and claims the benefit and priority of, U.S. patent application Ser. No. 14/305,357, filed on Jun. 16, 2014, which is a continuation-in-part of U.S. patent application Ser. No. 13/325,953, filed on Dec. 14, 2011, now U.S. Pat. No. 8,752,535, which claims priority to: (i) U.S. Provisional Patent Application No. 61/494,500, filed on Jun. 8, 2011; (ii) U.S. Provisional Patent Application No. 61/440,563, filed on Feb. 8, 2011; and (iii) U.S. Provisional Patent Application No. 61/422,770, filed on Dec. 14, 2010. The entire contents of the foregoing applications are hereby incorporated by reference. 
     
    
     FIELD 
       [0002]    The present disclosure relates to devices for decocking a cocked crossbow. More particularly, the disclosure relates to a crossbow having an integrally incorporated device for facilitating decocking of the crossbow without dry firing or firing a projectile. 
       BACKGROUND 
       [0003]    The disclosure relates to a crossbow that integrates a device uncocking of the crossbow, also called decocking of a crossbow. More directly, the disclosure relates to uncocking or decocking a ready-to-fire crossbow without dry firing or firing a projectile known in the art as an arrow or sometimes referred to as a bolt, a medieval term for a short arrow. 
         [0004]    Crossbows are generally cocked by a manually drawing the bowstring by hand to a loaded position or by using a drawstring or a winch-type cranking mechanism that draws the bowstring that is attached to the bowlimbs of the crossbow into a loaded position where the string is locked by a trigger mechanism. This load also known as potential elastic energy is measured in the art today by draw pounds. Most modern crossbows bear draw weights from 100-200 pounds. Once the release mechanism is actuated by the trigger, the bowstring is released and the potential elastic energy transitions to potential kinetic energy. 
         [0005]    Drawing a crossbow string to a cocked position is accomplished in several ways. Most commonly today, crossbows are outfitted with a steel or aluminum stirrup mounted on the front of the crossbow. The stirrup is used to hold the front of the bow down with one foot, while the bowstring is drawn using a drawstring typically comprised of braided nylon or polypropylene rope attached to hooks on each end with a “T” or “D” handle that traverses on the drawstring. By attaching the hooks to the bowstring, then stepping in the stirrup and pulling on the handles in an upward motion, the bowstring of the crossbow is drawn into a loaded cocked position. 
         [0006]    Another method of cocking the crossbow is a cranktype mechanism. This mechanism uses a gear reduction manual cranking means as the method to draw the bowstring into the loaded position. Efficient as a cocking device, it is generally not recommended to attempt to uncock or decock the crossbow using this device as it can and may cause serious injury to the operator and potentially damage to the crossbow. 
         [0007]    Once the bow is cocked, this stored load of elastic energy can be released transitioning to potential kinetic energy by the actuation of a trigger mechanism releasing the bowstring, which then propels a projectile known as an arrow although sometimes referred to as a bolt, with tremendous thrust and speed, away from the crossbow. This is also the typical manner of uncocking, decocking or unloading a cocked or loaded crossbow, which can result in losing, damaging or destroying the deployed arrow. In some jurisdictions it is illegal to exit a hunting area with a loaded weapon, such as a crossbow, requiring one to discharge the crossbow, propelling the arrow prior to exiting the field, a potentially dangerous and inefficient manner of unloading. 
         [0008]    Accordingly, there is a need for a decocking structure that can be incorporated into a crossbow structure and operable to decock the crossbow without dry firing or tiring a projectile. 
       SUMMARY 
       [0009]    The disclosure provides a crossbow having an integrated decocking system. 
         [0010]    In one aspect, a crossbow according to the disclosure includes a stock having a static portion and a movable portion, a bow having a bowstring, a bowstring catch, a resistance system, and a bowstring coupling system coupled to the resistance system. 
         [0011]    The resistance system includes a fluid containing cylinder having a movable piston and located within the static portion of the stock, and a shaft extending from the piston and having a terminal end. The piston is movable between a first position and a second position, and the cylinder includes an orifice having a size and extending through the piston to enable fluid to travel from one side of the piston to the other and to control the movement of the piston to a desired rate. 
         [0012]    The bowstring coupling system includes a cable having a first portion releasably securable to the bowstring and a second portion of the cable interfacing with a location on the shaft of the resistance system. 
         [0013]    The crossbow is decocked from a cocked state by releasably securing the cable to the bowstring, applying pressure to the piston by pulling on the shaft to extend the shaft, then actuating the catch to release the bowstring, wherein the released bowstring applies pressure to retract the shaft, which pressure is resisted by the resistance system, with the size of the orifice controlling the retraction of the shaft and thereby controlling travel of the bowstring and decocking of the crossbow. 
         [0014]    In another aspect, a crossbow according to the disclosure includes a bow having a bowstring, a bowstring catch, a resistance system operatively associated with the crossbow, and a bowstring coupling system coupled to the resistance system. 
         [0015]    The resistance system includes a fluid containing cylinder having a movable piston, the piston being movable between a first position and a second position at a desired rate. 
         [0016]    The bowstring coupling system includes a cable having a first portion releasably securable to the bowstring and a second portion of the cable interfacing with the resistance system. 
         [0017]    The crossbow is decocked from a cocked state by releasably securing the cable to the bowstring, applying pressure to the piston, then actuating the catch to release the bowstring, wherein the released bowstring applies pressure, which pressure is resisted by the resistance system to control travel of the bowstring and decocking of the crossbow. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    Further advantages of the disclosure are apparent by reference to the detailed description when considered in conjunction with the figures, which are not to scale so as to more clearly show the details, wherein like reference numbers indicate like elements throughout the several views, and wherein: 
           [0019]      FIGS. 1-3  show a crossbow according to the disclosure having an integrated decocking system. 
           [0020]      FIGS. 4-7  depict activation of the decocking system so that the crossbow may be decocked. 
           [0021]      FIGS. 8-12  operation of the decocking system to decock the crossbow. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    With reference to the drawings, there is shown a crossbow  10  having a decocking system  12  integrated into the crossbow  10 . The decocking system  12  is operable to enable decocking of the crossbow  10  without The crossbow  10  is shown in a relaxed state in  FIGS. 1-3 .  FIGS. 4-7  show the crossbow  10  in a tensioned state in which the crossbow is typically loaded with a bolt or arrow, with  FIGS. 4-7  showing activation of the decocking system  12  so that the crossbow  10  may be decocked without dry firing thereof and without firing of a bolt or arrow.  FIGS. 8-12  shows operation of the decocking system  12  to decock the crossbow  10 . 
         [0023]    The crossbow  10  includes a bow  14 , bowstring  16 , trigger  18 , a stock including a forestock  20  and a butt stock  22  having a static portion  22   a  and a movable portion  22   b,  a catch  24 , and arrow groove  26 . An arrow or bolt is oriented in the groove  26  so that a nock of the bolt is maintained in contact with a central portion of the bowstring  16  retained by the catch  24 . To fire the crossbow  10 , a user activates the trigger  18 , which manipulates the catch to release the bowstring and thereby fire the bolt, and decock the crossbow. 
         [0024]    The decocking system  12  includes a resistance system  30  and a bowstring coupling system  32 . The resistance system  30  supplies a resistance force to enable controlled return of the crossbow from the drawn state to the relaxed state. In this regard, the bowstring coupling system  32  couples the bowstring  16  to the resistance system  30  so as to enable the resistance system  30  to interact with the bowstring  16 . 
         [0025]    The resistance system  30  may include a double-acting fluid cylinder  40 . In this regard, the term “fluid” will be understood to encompass both liquid and gas cylinders. A preferred fluid cylinder is a pneumatic cylinder having an internal piston from which extends in one direction a shaft  42 . A through-bored orifice extends through the piston to permit gas/air for other fluid) to travel from one side of the piston to the other side, it being understood that the size of the orifice controls passage of fluid and, hence, travel of the piston and, hence the shaft  42 , connected to the piston. A desired dimension of the orifice is 1/16 inches. The cylinder  40  includes an endcap  40   a  at each end of the cylinder  40 , with the shaft  42  extending outwardly through one of the endcaps  40   a.  The cylinder also includes a pair of ports located at opposite ends of the cylinder  40  for introduction of fluid (air for a pneumatic cylinder) into the cylinder  40 . Double acting pneumatic cylinders utilize air pressure to control movement in both the extending and retracting strokes, i.e., extension of the shaft out of the cylinder and retraction into the cylinder. In this regard, as will be explained more filly below, manual pressure is provided by pulling on the movable portion  22   b  of the butt stock  22  coupled to the end of the shaft  42  to extend the shaft  42  and, when the bowstring  16  is released, the bowstring  16  applies pressure to retract the shaft  42 , with the size of the orifice controlling the retraction of the shaft  42  and thereby controlling de-tensioning of the crossbow  10 . The cylinder  40  may be otherwise integrated into the crossbow  10  and need not necessarily be located within the butt stock  20 . 
         [0026]    The coupling system  32  couples the resistance system  30  to the bowstring  16  and includes a pair of pulleys  50  rotatably located on the shaft  42  interior of the movable portion  22   b  of the butt stock  22 , a pair of cable cords or decocking cables  52 , one trained around each of the pulleys  50 . One free end of each of the cables  52  is secured to a spring-loaded cable reel  54 , and the other free end of each of the cables  52  is attached to a bow string hook  56  or other connecting structure for releasably connecting the end of the cables  52  to the bowstring  16 . Thus, each of the cables  52  is connectable to the bowstring  16 . While a single cable could be utilized, it is preferred to utilize at least two for redundancy. Each of the bow string hooks  56  is attached to one side of a cradle  58  that is releasably positionable on the crossbow  10  adjacent the arrow groove  26 . The cradle  58  is nominally positioned and maintained out of the way of the arrow groove  26 . However, when desired to activate the decocking system  12 , the cradle  58  is positioned within the arrow groove  26  so that the hooks  56  engage the bowstring  16 . In addition, the cradle  58  is configured to include a rearward surface that simulates the shape of a bolt so as to cooperate with safety features of the bow  10  that serve to disengage the trigger  18  when a bolt is not loaded and prohibit dry firing of the bow  10 . The cable reel  24  serves to retract the other ends of the cables  52  to maintain them taught relative to the static portion  22   a  of the butt stock  22 . An additional pulley  60  is desirably located within the interior of the static portion  22   a  of the butt stock  22  for separating the cables  52  to avoid tangling, one of the cables  52  being routed over the pulley  60  and the other over the pulley  60 . Additional pulleys and the like may be used to reduce friction and the like for routing the cables  52  in and out and within the butt stock  22 . 
         [0027]    To utilize the decocking system  12  with a cocked crossbow, the bolt or arrow is removed and the system  12  is arranged to fill the cylinder  40  with fluid and the cradle  58  is located in the arrow groove  26  to position the hooks  56  to engage with the bowstring  16 . This is depicted in the sequence of  FIGS. 4-7 . For example, as shown in  FIGS. 4 and 5 , the cradle  58  is moved from its inactive position out of the way of the groove  26  and positioned on the groove  26  with the hooks  56  located adjacent the bowstring  16 . Next, as shown in  FIGS. 6 and 7 , the movable portion  22   b  of the butt stock  22  is pulled rearward which serves to extend the shaft  42  and thereby draw fluid (air) into the piston  40 . This also serves to tension the cables  52  and pull the hooks  56  into engagement with the bowstring  16 . 
         [0028]    To decock the bow  10 , as depicted in  FIGS. 8-12 , the trigger  16  is actuated to release the bowstring from the catch  24 . The force supplied by the bow  14  via the bowstring  16  acts via the cables  52  to urge the piston and the shaft  42  to the retracted position in the cylinder  40 . This movement of the piston forces fluid through the orifice thereof, moving the fluid from the front of the piston to behind the piston within the cylinder  40 . The small orifice size regulates the fluid volume at a specific flow rate, permitting the piston to move through the cylinder  40  at a slow regulated pace, thus allowing the crossbow to decock under a controlled state. By doing so, the bowstring  16  which is attached to the bow, moves slowly from a tensioned position to a neutral uncocked position. 
         [0029]    Accordingly, it will be appreciated that crossbows according to the disclosure include an integrated decocking system that enables a bowstring of the crossbow to be positioned from a cocked, ready-to-fire position, to an uncocked and at-rest position without firing a projectile or without dry firing the crossbow. 
         [0030]    The foregoing description of preferred embodiments for this disclosure has been presented for purposes of illustration and description, it is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiments are chosen and described in an effort to provide the best illustrations of the principles of the disclosure and its practical application, and to thereby enable one of ordinary skill in the art to utilize the disclosure in various embodiments and with various modifications as are suited to the particular use contemplated.