Abstract:
An archery bow string suppression device with adjustable spring tension and isolated free floating transfer rod designed to be used to dampen the shock and vibration normally associated with firing a bow or crossbow.

Description:
REFERENCE TO RELATED APPLICATIONS 
       [0001]    This patent application claims the benefit of U.S. Provisional Application No. 61/188,053 filed on Aug. 6, 2008, the disclosure of which is incorporated herein in its entirety by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates generally to archery bows, and more specifically to an apparatus that is attached to a compound bow to suppress vibration and sound associated with a bow string when an arrow is released. 
         [0004]    2. Description of Related Art 
         [0005]    The compound bow is a popular form of bow that allows a user to achieve greater accuracy and distance relative to other types of bows. The compound bow consists of a rigid riser which is the support member for the limbs and a string suppressor. The limbs are very stiff members and a levering system, usually of cables and pulleys are used, to cause the limbs to bend to store all the energy of the bow. 
         [0006]    As a user pulls on the bow string, the pull increases to a peak and then “lets off”. This reduced force, or let off, allows a user to more easily hold the bow fully drawn while taking aim. A user will usually use a mechanical release that attaches to the bowstring near the point where the arrow attaches to provide a more consistent release. 
         [0007]    The compound bow has a relatively low weight and, therefore, is more sensitive to torque, vibration and slight movements of the users hand and/or arm as an arrow is fired. Torque can occur as the arrow leaves the bow. A problem that can occur with compound bows is the build up of a vibration as an arrow is fired. Normally between 70-85% of the stored energy in the limb members is transferred to the arrow as kinetic energy. Thus, about 15% to 30% of the stored energy is transferred to and absorbed by the limbs and the riser. It is believed that this energy that is transferred to and absorbed by the limbs and the riser is the cause of vibration that occurs in the rigid riser and the stiff limb members. 
         [0008]    What is needed is a string suppressor that can be attached to the riser of a compound bow that allows an archer to shoot more accurately by reducing vibration of the bow string when the arrow leaves the bow. 
       SUMMARY OF THE INVENTION 
       [0009]    There is disclosed an archery bow string suppressor adapted to be removably attached to a fitting on an archery bow includes a shaft having a cushion member of vibration damping material mounted on a first end of the shaft for contacting a bow string and dampening string vibrations and a body having a chamber within which the second end of the shaft is located. A mounting bolt having a head surrounded by an O ring is located at one end of the chamber. A spring is also located in the chamber and functions as a shock absorber as the bow string hits the cushion member of said rod. 
         [0010]    The foregoing has outlined, rather broadly, the preferred feature of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiment as a basis for designing or modifying other structures for carrying out the same purposes of the present invention and that such other structures do not depart from the spirit and scope of the invention in its broadest form. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Other aspects, features, and advantages of the present invention will become more fully apparent from the following detailed description, the appended claim, and the accompanying drawings in which similar elements are given similar reference numerals. 
           [0012]      FIG. 1  is a side perspective view of a string suppressor with an offset bracket for attachment to the riser of a compound bow in accordance with the principles of the invention; 
           [0013]      FIG. 2  is an exploded view of the string suppressor of  FIG. 1 ; 
           [0014]      FIG. 3  is a side view of two types of elastomer boots that can be placed on the end of the shaft for contact with the string of a bow; 
           [0015]      FIG. 4  is a side perspective view of a string suppressor with a mounting bolt for attachment to the riser of a compound bow in accordance with the principles of the invention; and 
           [0016]      FIG. 5  is a partial view of a riser of a compound bow attached to a string suppressor with a mounting bolt in accordance with the principles of the invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0017]    The primary function of the string suppressor disclosed is to reduce string vibration and sound associated with the string when an arrow is being fired from a bow. 
         [0018]    The string suppressor has two principle components, a main body and a shaft. 
         [0019]    Referring to  FIG. 1 , there is shown is a side perspective view of a string suppressor  10  which includes a main body  12  and a shaft  14 . An offset bracket  16 , which is attached to the lower end of the main body  12  allows the shaft to be oriented to be aligned with and engage the string of a bow when an arrow is fired. 
         [0020]    Referring to  FIG. 2 , there is an exploded view of the string suppressor  10  on  FIG. 1 . The main body  12  and the parts that are located in the main body are shown. The main body is designed with a chamber  18 . One end of the chamber supports a thread  20  and the opposite end has an opening  22  within which is a bushing  24  composed of a smooth low friction material such as nylon, Teflon, rubber, Delrin or the like. The shaft  14  is supported by bushing  24  which helps to dampen vibrations by eliminating any metal to metal contact between the shaft and the main body  12 , allowing the shaft to move in and out without binding. 
         [0021]    The top or string end  26  of the shaft  14  is attached to an elastomer boot  28  and the opposite end of the shaft has threads  30  for receiving two bushings  32 ,  34 . Bushings  32 ,  34  are composed of Viton or of any other material that can be adjusted along the shaft while also serving to eliminate metal to metal contact. 
         [0022]    The bushings are provided for adjusting spring tension, shaft travel and shaft length. The bushings also eliminate metal to metal contact and aid in reducing vibration. Each bushing fits tightly around the threaded end of the shaft and functions as a threaded nut. The bushings can be moved up or down the threaded portion of the shaft by being turned either clock wise or counter clock wise. In place of the threads on the end of the shaft, any type of etching or cross grid on the shaft end can be used which will hold the bushings in place while also allowing a user to adjust their location. 
         [0023]    Bushing  34  is provided to control spring tension and shaft travel when an arrow is fired. Bushing  32 , which is independent of bushing  34 , is used to provide the final adjustment of the shaft length toward the bow string which allows a user to locate the end of the elastomer boot to be spaced slightly away from the bow string while at brace height. 
         [0024]    A cap  38 , which includes a centrally located threaded mounting bolt  40 , is threaded into one end of the main body  12 . The opening in cap  38  is sized to provide a slip fit for the threaded shaft  42  of the mounting bolt. The diameter of the head of the mounting bolt is less than the diameter of the cap and is located within an O ring  44 . A spring  36 , which is in compression, is located between the bushing  34  and cap  38 . Thus, one end of spring  36  seats on the bushing  34 , which can be of Viton, and the opposite end of the spring seats on O ring  44 . The end of spring  36  does not contact the small diameter head of the mounting bolt  40 . Spring  36  can be coated with a plastic covering, located within a plastic sleeve or coated with any material or substance which will dampen vibration and allow for a quite and smooth motion of the spring while eliminating any metal to metal contact. 
         [0025]    The threaded end  42  of bolt  40  is sized to be threaded into a threaded receiving opening in the riser of a compound bow or into a threaded opening of an off set bracket  16 . When an off set bracket is used, the threaded bolt  48  is used to mount the string suppressor to the riser of a compound bow. 
         [0026]    In some instances the opening in the riser of the compound bow that is provided for receiving a string suppressor is a smooth bore opening with a set screw, it is not threaded. With bows of this type, cap  38 , bolt  40  and off set bracket  16  of  FIG. 2  are removed and a second cap  60  has an off center stud, one end of which is threaded into the second cap and the other end is threaded into a rod of metal such as aluminum which has a smooth outside surface. This rod is sized to fit into the smooth bore opening in the riser and is held in position with the set screw. Threading the off center stud on the second cap into the rod allows the string suppressor to be oriented relative to the bow string by rotating the string suppressor about the off center stud. 
         [0027]    The outside surface of the main body includes three grooves  25  for receiving O rings. The O rings are provided to allow a user to grip the body  12  when the cap  38  is being unscrewed from the main body  12 , or the main body is being attached to or removed from the bow and also serve to absorb vibration resonance from main body  12  before it can be transferred into bow riser. 
         [0028]    The shaft, which is provided to transfer energy from the string to a spring located in a chamber in the main body  12 , includes a scale  49 . The scale is provided to allow a user to see exactly how far the shaft traveled when an arrow is shot. The scale is located where the shaft enters the main body and operates with a floating O ring  50  that is provided to indicate the travel distance of the shaft. To use, a user slides the O ring down the shaft until it touches the top of the main body. When a user shoots an arrow, the string will hit boot  28  pushing in shaft  14  into the main body against the force of spring  36 , and then return. As the shaft returns to its rest position, O ring will follow and move with the shaft. The distance between the top of the main body and the O ring is the distance that the shaft traveled. 
         [0029]    Referring to  FIG. 3  there is shown a side view of two types of elastomer boots  28  that can be placed on the end of the shaft  14  for contact with the string of a bow. 
         [0030]      FIG. 4  is a side perspective view of a string suppressor  10  with a standard mounting bolt for attachment to the riser of a compound bow. 
         [0031]      FIG. 5  is a partial view of a riser of a compound bow attached to a string suppressor  10  with a mounting bolt. 
         [0032]    The string suppressor disclosed differs from other string suppressors in that it uses a spring to dampen string vibration and can be adjusted for tension and travel and isolates rod  14  from direct metal to metal contact from the remaining components of the invention. 
         [0033]    The advantages of the string suppressor disclosed are that: 
         [0000]    1. The string suppressor has the ability be mounted directly in-line or offset.
 
2. The string suppressor offers adjustable tension to match a user&#39;s individual set-up.
 
3. The string suppressor offers a smooth and progressive stop opposed to static rod suppressors which abruptly halt the string&#39;s forward progress.
 
4. The string suppressor has adjustable travel
 
5. The string suppressor has a travel indicator gauge which lets a user know exactly how far the string has moved when an arrow is shot.
 
6. The string suppressor is not affected by temperature.
 
         [0034]    While there have been shown and described and pointed out the fundamental novel features of the invention as applied to the preferred embodiments, it will be understood that various omissions and substitutions and changes of the form and details of the apparatus illustrated and in the operation may be done by those skilled in the art, without departing from the spirit of the invention.