Patent Publication Number: US-10760869-B2

Title: Archery bow pulley engagement

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Patent Application No. 62/599,624, filed Dec. 15, 2017, the entire content of which is hereby incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates generally to archery bows and more specifically to compound archery bows having at least one rotating cam assembly. Some compound archery bows include a rotating cam assembly and a rotating pulley, and a section of a bowstring wraps around the pulley. An example of such a bow is disclosed in U.S. Pat. No. 5,368,006, the entire content of which is hereby incorporated herein by reference. 
     There remains a need for novel compound bow structures that provide improvements in efficiency over prior bows. 
     All US patents and applications and all other published documents mentioned anywhere in this application are incorporated herein by reference in their entirety. 
     Without limiting the scope of the invention a brief summary of some of the claimed embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention may be found in the Detailed Description of the Invention below. 
     A brief abstract of the technical disclosure in the specification is provided as well only for the purposes of complying with 37 C.F.R. 1.72. The abstract is not intended to be used for interpreting the scope of the claims. 
     BRIEF SUMMARY OF THE INVENTION 
     In some embodiments, an archery bow comprises a riser, a first limb and a second limb. The first limb supports a first rotatable member, which comprises a cam. The second limb supports a second rotatable member, which comprises a pulley comprising a peripheral groove. A ring comprising an elastomeric material is positioned in the peripheral groove. A power cable is arranged to be taken up on the cam as the bow is drawn. A string segment is arranged to wrap around the pulley. The string segment contacts the ring. 
     In some embodiments, an archery bow comprises a riser, a first limb and a second limb. The first limb supports a first rotatable member, which comprises a cam. The second limb supports a second rotatable member, which comprises a pulley comprising a peripheral groove comprising surface texturing. A power cable is arranged to be taken up on the cam as the bow is drawn. A string segment is arranged to wrap around the pulley. A portion of the string segment is oriented in the peripheral groove. 
     These and other embodiments which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages and objectives obtained by its use, reference can be made to the drawings which form a further part hereof and the accompanying descriptive matter, in which there are illustrated and described various embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A detailed description of the invention is hereafter described with specific reference being made to the drawings. 
         FIG. 1  shows an embodiment of an archery bow. 
         FIG. 2  shows a more detailed view of a portion of the bow shown in  FIG. 1 . 
         FIG. 3  shows an exploded view of the bow of  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     While this invention may be embodied in many different forms, there are described in detail herein specific embodiments of the invention. This description is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated. 
     For the purposes of this disclosure, like reference numerals in the figures shall refer to like features unless otherwise indicated. 
       FIG. 1  shows an embodiment of an archery bow  10 . In some embodiments, a bow  10  comprises a riser  12 , a first limb  14  and a second limb  16 . The first limb  14  supports a first rotatable member  20  and the second limb  16  supports a second rotatable member  30 . 
     The bow  10  shown in  FIG. 1  comprises a single-cam bow, for example as disclosed in U.S. Pat. No. 5,368,006. In some embodiments, the second rotatable member  30  comprises a pulley having a constant radius. In some embodiments, the bow  10  comprises a power cable  40  and the first rotatable member  20  comprises a cam track  22  arranged to take up the power cable  40  as the bow  10  is drawn. In some embodiments, the bow  10  comprises a string segment  50  that extends from the first rotatable member  20  to the second rotatable member  30 , wraps around the second rotatable member  30  and extends back to the first rotatable member  20 . The string segment  50  comprises a bowstring portion  52  and a control cable portion  54 . Desirably, the bowstring portion  52  comprises a nocking point  15 . In some embodiments, the first rotatable member  20  comprises a bowstring track  21  and a secondary feed out track  24 . As the bow  10  is drawn, the bowstring track  21  feeds out the bowstring portion  52  of the string segment  50 , and the secondary feed out track  24  feeds out the control cable portion  54  of the string segment  50 . The control cable portion  54  extends to the second rotatable member  30  and becomes a second end of the bowstring portion  52  as it passes over the second rotatable member  30 . 
     In some embodiments, a bow  10  comprises string suppressors  18 , for example as taught in U.S. RE42842. 
     It has been discovered that the second rotatable member  30  does not necessarily remain engaged with the string segment  50  as the bow  10  is fired. For example, the string segment  50  can slip with respect to the second rotatable member  30 . For example, a reference marking can be placed on the second rotatable member  30  and aligned with a reference marking on the string segment  50 . The bow  10  can be drawn and fired, and the reference markings can come to rest in a non-aligned orientation. A traditional understanding of bow dynamics tends to suggest that slipping can provide greater arrow speed, as energy that is not used to spin the second rotatable member  30  could reach the arrow. However, it has been discovered that increasing the engagement between the string segment  50  and the second rotatable member  30  can result in higher arrow speeds. 
     The engagement between the string segment  50  and the rotatable member  30  can be increased in any suitable manner. In some embodiments, higher friction materials can be used—for example on the rotatable member  30 , on the string segment  50 , or both. In some embodiments, surface texturing can be applied to either or both of the rotatable member  30  and/or the string segment  50 . 
       FIG. 2  shows a more detailed view of a portion of the bow  10  of  FIG. 1 , and  FIG. 3  shows the structure of  FIG. 2  in an exploded view. 
     In some embodiments, the rotatable member  30  comprises surface texturing  60  such as knurling. Surface texturing  60  can be applied in any suitable manner. Surface texturing  60  can comprise protrusions and recesses formed in a surface of the rotatable member  30 , which can increase engagement between the rotatable member  30  and the string segment  50 . In some embodiments, knurling comprises a plurality of X-shaped grooves. In some embodiments, X-shaped grooves overlap. 
     In some embodiments, a string track  32  comprises a recess formed in the rotatable member  30 . In some embodiments, a surface of the string track  32  comprises surface texturing. 
     In some embodiments, a high friction material can be applied to the rotatable member  30 . In some embodiments, an elastomeric coating is applied to at least the string track  32  of the rotatable member  30 . In some embodiments, a rubber, elastomeric material, silicone material, or other suitable material can be applied to the string track  32 , which comprises a higher coefficient of friction than the material used to form the rotatable member  30 . 
     In some embodiments, a high friction material can be attached to the rotatable member  30  and positioned in the string track  32 . In some embodiments, an abrasive material can be attached to the rotatable member  30  and positioned in the string track  32 . In some embodiments, a ring  62  comprising an elastomeric material and/or rubber is positioned in the string track  32  of the rotatable member  30 . A ring  62  can comprise any suitable material and desirably comprises a material having a higher coefficient of friction than the material used to form the rotatable member  30 . In some embodiments, a ring  62  comprises an O-ring, for example having a circular cross-section. In some embodiments, a ring  62  comprises a rubber band. In some embodiments, a ring  62  comprises a non-circular cross-sectional shape. 
     In some embodiments, an adhesive  64  can be applied to either or both of the string track  32  and/or the string segment  50 . 
     In some embodiments, the string segment  50  comprises a high friction material. In some embodiments, the string segment  50  comprises an abrasive material. In some embodiments, the string segment  50  comprises Kevlar, which tends to have a coefficient of friction several times greater than a coefficient of friction of common polymeric materials that are used to make bowstrings. 
     In some embodiments, the string segment  50  comprises a serving  66  comprising a high friction material such as Kevlar, an elastomeric material, etc. In some embodiments, a serving  66  comprises a helical wrapping of material around the string segment  50 . A serving can extend for any suitable length portion of the string segment  66 . In some embodiments, several short portions of serving  66  are spaced apart along a length of the string segment  50 . 
     In some embodiments, a higher friction tube of material can be provided around the string segment  50 . For example, in some embodiments, a rubber or elastomeric shrink tubing can be attached to the string segment  50 . 
     The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this field of art. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to.” Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims. 
     Further, the particular features presented in the dependent claims can be combined with each other in other manners within the scope of the invention such that the invention should be recognized as also specifically directed to other embodiments having any other possible combination of the features of the dependent claims. For instance, for purposes of claim publication, any dependent claim which follows should be taken as alternatively written in a multiple dependent form from all prior claims which possess all antecedents referenced in such dependent claim if such multiple dependent format is an accepted format within the jurisdiction (e.g. each claim depending directly from claim  1  should be alternatively taken as depending from all previous claims). In jurisdictions where multiple dependent claim formats are restricted, the following dependent claims should each be also taken as alternatively written in each singly dependent claim format which creates a dependency from a prior antecedent-possessing claim other than the specific claim listed in such dependent claim below. 
     This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.