Patent Publication Number: US-6708684-B2

Title: Cable vibraguard

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a cable guard for a compound bow. More specifically, a cable guard that reduces the noise generated by the vibration of the cables, and at the same time, helps increase the speed of the arrow. 
     2. Description of the Related Art 
     In the sport of archery, the basic configuration and operation of compound bows are generally known as they have been in use for a long time. Compound bows are used a great deal in hunting, because they provide several distinct advantages. Compound bows mechanically reduce the maximum draw weight, allowing the archer to hold full draw at a draw weight less than that of the required maximum. 
     Compound bows also achieve more gradual arrow acceleration upon release with reduced stress on the arrow and the archer, which increases the arrow speed and shooting accuracy. 
     Compound archery bows include tension cables and a bowstring, which are connected between the upper and lower bow limbs. It is customary, in order to minimize any twisting torque on the bow limbs, to dispose the bowstring and the tension cables relatively close together, proximate the vertical centerline of the bow. 
     A problem presented by compound bows is that a noise is generated upon releasing the bowstring to propel the arrow. When the bowstring reaches the end of its arrow-propelling path, the cables which cross in the center portion of the bow rub against each, causing frictional forces that produce cable wear and create a noise or sound which may alert game birds and animals. 
     A popular solution to this problem is to provide compound bows with a cable guard having a rod mount which, by rotation of the mount, provides a selectable degree of displacement of the tension cable from the plane of the path of the bowstring. The rod mount is generally threaded directly into the bow handle area, either above or below the handgrip. 
     The prior art shows that numerous attempts have been made to maintain the lateral spacing of the cables and reduce the friction between the cables. 
     U.S. Pat. No. 4,452,222 entitled “Cable Guard for a Compound Bow” to Quartino et al. discloses a cable guard, which comprises a rod that extends from the bow handle and beyond the cables when the bow is in a fully drawn position. The rod is positioned laterally from the bowstring to void any interference with the bowstring. A cable-retaining member is rotatably and slidably mounted on the rod. The cable-retaining member includes two bores that are perpendicular to the rod for slidably receiving the cables to hold them in a lateral spaced relationship with the bowstring. 
     U.S. Pat. No. 4,596,228 entitled “Cable Separator for Compound Bows” to Smith discloses a rod attached to the handle portion of the bow that extends rearwardly beyond the bowstring. Positioned about the external surface of the rod is a cable guard assembly which positions a cable on either side of the bow. The purpose of the invention is to prevent an interfering contact of the cable strands with an arrow during impelling flight of the arrow from the bow, thereby obviating impairment of the true flight of the arrow released from the bow. 
     U.S. Pat. No. 5,718,213, entitled “Swing Arm Cable Guard” to Gallops Jr. et al., discloses a cable guard, including a support member and a swing arm pivotally connected thereto. A cable retaining means having two bores therein for retaining the cables is pivotally mounted on the swing arm. The angle between the support member and the swing arm is such that when the bow is drawn, the distance between the cables, which is contained in the cable retaining means, and the plane of the bowstring travel, is less than the distance between the cables and the plane of bowstring travel when the bow is at rest. Since the cables are closer to the plane of bowstring travel when the bow is drawn, the cables and bow limbs are less stressed when the bow is drawn. The cable guard retaining means may not be adjusted to change the distance between the cable guard retaining means and bowstring. 
     In prior art, cable guards of the type described above, the rod on which the retaining members were slidably mounted, was required to be of sufficient length to permit the retaining members to be mounted thereon when the bow was in the drawn condition. 
     Unfortunately, the rod length can be a potential distraction to the archer when the arrow is being shot. Another problem presented by the rod of the prior art is that most archers do not remove the cable guard from their bow for transport, and since many forms of transportation require bows to be cased for transport, the use of such cable guards requires substantial storage area and larger bow cases. 
     Further, the rod and sliding retainer introduces additional friction into the system, for example, the increased friction force between the cables and the sliding retainer and between the sliding retainer and the support rod as the bowstring is moved from brace position to full draw. 
     Some of these disadvantages appear to have been overcome by the cable guard disclosed in U.S. Pat. No. 4,834,061 entitled “Cable Vibraguard” to the present inventor, in which a support member has a swing arm pivotally attached thereto. A cable retaining member having two openings therein is located at the free end of the swing arm. The cables pass through and are contained within the openings of the retaining member. When the bow is drawn, the cables travel in a plane parallel to the general direction of the bowstring and cause the retaining member and connected swing arm to be pivoted away from the support member and the bow handle. The present invention is an improvement of the cable guard disclosed in this patent. 
     The present invention concerns another means for reducing the frictional forces between the cables and the bores of the retaining means. 
     Another problem presented by a conventional compound bow is that a considerable amount of energy stored in bow limb is wasted by propelling the bow limb forward when the drawn bowstring is released. Instead, it is desirable to use at least a portion of this wasted energy to propel an arrow. 
     The arrow speed depends upon several factors, one of the most important being the amount of energy put into the bow. Generally speaking, the more total energy put into the bow, the faster that the arrow will be propelled. Increased arrow speed is desirable, especially when hunting and shooting heavy arrows. 
     Another problem presented by a conventional compound bow is that the crossing cables are located in the point of view of the archer, thus the visibility of the archer is diminished. 
     Thus, the present inventor feels the necessity of providing a cable guard for a compound bow that is simple, quiet, inexpensive, and less susceptible to wear and tear, increases the visibility of the archer, and, at the same time, increases the arrow speed. 
     SUMMARY OF THE INVENTION 
     Therefore, it is an object of this invention to provide a cable guard that separates the cable positioned between the bowstring and the handle portion of a compound bow. 
     It is yet another object of the present invention to provide a cable guard that decreases the noise generated during the use as to not alert or frighten game birds and animals. 
     It is yet another object of the present invention to provide cable guard in which the frictional forces generated between the cables and the cable retaining members are reduced when the bow is drawn. 
     It is yet another object of the present invention to provide a cable guard which does not extend beyond the cables positioned between the bowstring and the handle portion of the compound bow. 
     It is yet another object of the present invention to provide cable guard with reduced hand shock and vibration in order to avoid arm fatigue. 
     It is yet another object of the present invention to provide a cable guard which is economical to produce and maintain. 
     It is yet another object of the present invention to provide a cable guard that separates the cable positioned between the bowstring and the handle portion of a compound bow increasing the visibility of the archer. 
     It is yet another object of the present invention to provide a cable guard that helps increase the speed of the arrow. 
     In view of the foregoing disadvantages inherent in the known types of security systems in the prior art, the present inventor discovered a unique cable guard for use with a compound bow, the compound bow having a handle portion and a pair of opposite bow limbs, a first and a second cable which cross one another in extending between opposite bow limbs and a bowstring, the cable guard comprising: 
     a rod having a first end and a second end, wherein the first end of the rod is attach to the handle portion of the compound bow; 
     a housing disposed at the second end of the rod; 
     a pair of swing arms extending opposite to each other and outwardly from the housing in the direction of the bow limbs, the pair of swing arms pivotally connected about a point near one end of the housing; 
     a biasing means in contact with the other end of the housing and the second end of the rod; and 
     wherein when the bowstring is drawn to a draw position, the swing arms move in the direction of the bowstring moving the housing in the direction of the handle compressing the biasing means. 
     The cable guard further can include mounting means for attaching the first end of the rod to the handle portion of the compound bow; a biasing housing located near the second end of the housing, wherein the biasing housing comprises a center axis, wherein the second end of the rod runs through the center axis of the biasing housing; a pair of levers means, wherein each levers means is pivotally connected between the pivot point of the swing arm and the second end of the housing; and a cable guide means positioned at the first end of each swing arm, the cable guide means adapted slidably receiving and separating the first and second cable; 
     When the bowstring is drawn to a draw position, the cables move in the direction of the bowstring urging the swing arms in the direction of the bowstring. The movement of the swing arms moves the pair of lever means, and the movement the pair of lever means urges the biasing housing in the direction of the handle compressing the biasing means inside the biasing housing. 
     When the bowstring is release, the biasing housing moves back to it original position and the first and second cables are compelled to stop vibrating by the movement of the biasing housing returning to the original position thereby decreasing the amount of vibration noise produced by the vibrating of the first and the second cable. 
     The biasing housing includes a first portion and a second portion, wherein the diameter of the first portion is greater than the diameter of the second portion forming a seat. 
     The compression of the biasing means adds an extra tension force to the biasing means, and wherein the extra tension force provides the arrow with an increase speed. 
     In a first preferred embodiment, the biasing means comprises more than one spring. 
     Further, the present invention contemplates the use of an adjusting rod to engage the biasing means and change the pre-set compression force of the biasing means. 
     The foregoing has outlined rather broadly the more pertinent and important features of the present invention in order that the detailed description of the invention that follows may be better understood, and the present contribution to the art can be more fully appreciated. Additional features of the invention will be described hereinafter, which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying other security systems for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent structures do not depart from the spirit and scope of the invention as set forth in the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description taken in connection with the accompanying drawings in which: 
     FIG. 1 is a side view illustrating the cable guard of the present invention attached to a compound bow in a rest position; 
     FIG. 2 is a side view illustrating the cable guard of the present invention attached to a compound bow in a drawn position; 
     FIG. 3 is a partial section taken along line A-A 1  on FIG. 1; 
     FIG. 4 is a rear view of FIG. 3; 
     FIG. 5 is an enlarged side view of the present invention after the bowstring has been released; 
     FIG. 6 is an enlarged side view showing the present invention having a biasing means comprising more than one biasing member. 
     FIG. 7 is an enlarged side view of the present invention in a drawn position. 
     FIG. 8 is an exploded view of the cable guard of the present invention. 
     FIG. 9 is an enlarged side view of a single swing arm according to the first preferred embodiment of the present invention. 
     FIG. 10 a  is an enlarged side view of a single swing arm showing a leaf spring as biasing means. 
     FIG. 10 b  is an enlarged side view of a single swing arm showing an air spring as biasing means. 
    
    
     Similar reference characters refer to similar parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 is a side view illustrating the cable guard  10  of the present invention attached to a compound bow in a rest position. The cable guard  10  is used with a conventional compound bow  20  having a bow handle  30  and a pair of bow limbs  40 ,  50 . The first bow limb  40  and the second bow limb  50  are oppositely positioned in bow handle  30 . Bowstring  60  spans between a first bow tip  70  and a second bow tip  80 . The bowstring  60  then continues and extends over the pulleys  90 A,  90 B positioned at or proximate to each of the bow tips  70 ,  80 , and then the two ends of the bowstring  60 , designated first cable end  100  and second cable end  110 , cross to the opposite limb at which point they are attached to define a compound bow  20 . 
     FIG. 2 is a side view illustrating the cable guard of the present invention attached to a compound bow in a drawn position. 
     FIG. 3 is a partial section taken along line A-A 1  on FIG.  1  and provides greater detail of the cable guard  10  of the present invention. 
     The cable guard  10  of the present invention includes a rod  130 , a housing  160 , and a biasing housing  250 . 
     Rod 
     In its basic embodiment, the rod  130  includes a first end  140  and a second end  150 . The first end  140  has a diameter greater than the diameter of the second end  150 . 
     In a first preferred embodiment, the rod comprises a first section and a second section. The first section has a diameter greater than the diameter of the second section. 
     The first section includes an internal threaded end, and the second section includes an external threaded end. The external threaded end of the second section is threaded to the internal threaded end of the first section to form the rod. 
     The mounting means  120  firmly attaches the first end  140  of the rod  130  to the handle portion  30  of the compound bow  20 . 
     Housing 
     A housing  160  is disposed at the second end  150  of the rod  130 , the housing having a central axis, a first end, and a second end. The second end of the rod runs through the center axis of the housing; 
     The housing  160  includes a pair of swing arms  170 ,  180 . Each arm includes a first end  200  and a second end  205 , wherein the second end of each arm is pivotally connected about a point near the first end of the housing. The swing arms are connected to the housing  160  by using a fastening means such as floating pins  208 . 
     A cable guide means  190  are positioned at the first end  200  of each swing arm  170 ,  180 . Each cable retaining means  190  include openings  210  and  220  therein to retain cables  100  and  110 . The opening  210  has a depth greater than the depth of the opening  220  in order to avoid that the cables touch and rub into each other. 
     The cable guide means  190  slidably receive and separate the first cable  100  and second cable  110 . Thus, the first and second cable are slidably received and separated during the drawing and release of the bowstring  20 , ensuring that the first cable  100  and second cable  110  do not rub against each other, and decreasing the amount of noise produced by the vibrations of the first  100  and second  110  cables immediately after the bowstring  20  has propelled an arrow. 
     Further, the housing includes a pair of lever means  175 , wherein each lever means is pivotally connected between the pivot point of the swing arm and the second end of the housing. 
     The housing  160  further includes an internal stopper  215  to keep the housing means inside the housing. 
     Biasing Housing 
     The biasing housing  250  has generally tubular form and includes a first portion  255  and a second portion  260 . The diameter of the first portion is greater than the diameter of the second portion, thus a seat  272  is formed. 
     The biasing housing  250  includes a borehole  274 . The second end  150  of the rod  130  runs through the borehole  274  of the biasing housing  250  and the center axis of the housing  160 . A first washer  276  is in contact with the seat  272  of the biasing housing  250 . 
     A biasing means  185 , such as a spring, is disposed inside the biasing housing  250 . The biasing means  185  includes a first end  280  and a second end  290 . The seat  272  confines the biasing means to first portion of the housing  250 . 
     The second end  290  of the biasing means  185  is connected to a second washer  295 , which is in direct contact with the internal stopper  215  of the housing  160 . 
     The biasing means  185  is preferably a coil spring having a pre-set force. The coil spring is preferably made of steel, but can be made of any other suitable material. 
     The present invention contemplates also the use of any type of spring capable of storing power when compressed, such as an air spring, leaf spring, or other energy storage device as biasing means. 
     The biasing means  185  has an outer diameter slightly smaller than the inner diameter of the housing  250 . The inner diameter of biasing means is slightly greater than the diameter of the second end  150  of the rod  130 . 
     The present invention also contemplates the use of a biasing means  185  comprising more than one spring. (FIG. 6) 
     The length of the biasing means depends on the type of compound bow used and is controlled to provide a “stopped” action of the swing arms, thus will not interfere with the discharged bowstring and arrow. Thus, when the biasing means goes back to its normal relaxed position, the biasing means provides the bow with an immediate stopping action that prevents any further movement of the swing arms or the cables. 
     Optionally, the present invention contemplates the use of an adjusting rod  310  (FIG. 7) to engage the biasing means and change the pre-set compression force of the biasing means. 
     As can be seen from FIG. 1, rest position, the swing arms are substantially located in the same plane. In the drawn position, FIG. 3, the swing arms are diverging rearwardly to a substantially closed position. It will be seen that when bowstring  60  is drawn, cables  100  and  110  move in the direction of the bowstring and both cables retaining means  190  and swing arms  170 ,  180  are pivoted to the position shown in FIG.  2 . 
     When the bowstring drawn to a draw position, the cables move in the direction of the bowstring urging the swing arms in the direction of the bowstring. The movement of the swing arms moves the pair of lever means, and the movement the pair of lever means urges the biasing housing in the direction of the handle compressing the biasing means inside the biasing housing. 
     The compression of the biasing means adds extra tension force to the biasing means. Thus, upon releasing the bowstring, the arrow is propelled by the pre-loaded tension of the biasing means, the extra tension on the biasing means, and, of course, also by the tension put into the bow by the final draw of the bowstring. The biasing means causes the energy that propels the arrow to be greater than the energy, which is required on the final draw of the bow. This improves the speed of the arrow. 
     In a first preferred embodiment, the cable guard of the present invention includes only one swing arm  350  (FIG.  9 ). The swing arm is attached to a rod  360 , and the rod travels through the housing containing the biasing means  370 . As the swing arm folds back, the rod travels forward compressing the biasing means. When the bowstring is released, the swing arm is pushed forward by the rod and the extra tension on the biasing means causing an increase in the speed of the arrow. 
     Thus, the cable guard of the present invention helps to overcome the problem presented by a conventional compound bow regarding the waste of energy produced by propelling the bow limb forward when drawn bowstring is released. Thus, the additional energy allows the user to use a lighter compound bow without loosing arrow speed or to shoot a bow that is more powerful than he is capable. 
     Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims.