Compound bows

Abstract

Improved compound bows which are smaller, more compact, lighter, and more easily handled and serviced than compound bows of conventional construction but are nevertheless capable of propelling an arrow at an equal or higher velocity and with comparable or greater accuracy than a conventional bow. The improved bows are quieter than those of conventional construction and less apt to snag on brush or other obstacles. They have a rigid riser with ends to which string cams are rotatably mounted and cam-associated power units mounted to and towards the ends of the riser. Each power unit has a component which is elastically deformed to store potential energy as the bow is drawn and a power cable connecting the power storing component to the associated string cam. A bow string extends between and is connected at its opposite ends to the string cams. As the bow is drawn, the string cams are rotated in counter directions, pulling on the power unit cables and thereby elastically deforming and storing potential energy in the power unit components. When the bow string is subsequently released, the elastically deformable power unit components restore to rest configurations, this converting the stored potential energy to arrow propelling kinetic energy. A timing cable arrangement insures that the cams are synchronized to rotate in unison, avoiding the unwanted nock travel that might otherwise occur; and the power units have an adjustment feature which allows the force required to fully draw the bow to be changed.

1 . The combination of a compound bow and a bow string, the bow comprising: 
 a riser;    first and second string cams rotatably mounted to opposite ends of the riser for counter rotation in first directions as the bow is drawn and in second, opposite directions when an arrow is shot from the bow; and    string cam-associated power units which: (a) are mounted at opposite ends of the riser, and (b) are operable, as the bow is drawn, to store potential energy which is subsequently converted to arrow propelling kinetic energy when the bow string is subsequently released;    the bow string extending between and being connected to the string cams.    
   
   
       2 . A combination as defined in  claim 1  wherein the riser of the compound bow has: 
 an elongated center section with a hand grip intermediate its ends; and    first and second arms;    each arm being integrated at one end thereof with an end of the center section;    each arm being oriented at an angle relative to a bow string side of the riser and terminating in a free end spaced from a bow string side of the riser; and    the string cams being rotatably mounted to the free ends of the riser arms.    
   
   
       3 . A combination as defined in  claim 2  in which: 
 each of the string cam-associated power units of the compound bow has an elastically deformable component for storing potential energy as the bow is drawn.    
   
   
       4 . A combination as defined in  claim 3  wherein there is a pocket at the juncture of each riser arm and the riser center section housing, each pocket housing an elastically deformable power unit component.  
   
   
       5 . A combination as defined in  claim 3  in which each of the power units of the compound bow has a motion/power transmitting component connected between the deformable, energy storing component of the unit and the corresponding string cam.  
   
   
       6 . A combination as defined in  claim 1  in which each of the power units of the compound bow comprises: 
 an elastically deformable, energy storing component anchored relative to the riser; and    a motion/force transmitting component so operatively connected between the elastically deformable component and the corresponding string cam as to deform and store potential energy in that component as the bow is drawn and the string cam rotates in its first direction.    
   
   
       7 . A combination as defined in  claim 1  wherein the motion/force transmitting component of the power unit is attached to and displaces the free end of the elastically deformable component as the corresponding string cam rotates in its first direction.  
   
   
       8 . A combination as defined in  claim 6  wherein the elastically deformable component of each power unit of the compound bow is so configured that the free end of that component follows a path which remains generally normal to the motion/force transmitting component of the power unit as the free end of the elastically deformable component is displaced.  
   
   
       9 . A combination as defined in  claim 6  in which each power unit of the compound bow has a mechanical adjustment feature for so displacing the anchored end of that unit's elastically deformable component as to change the magnitude of the pull required to effect a full draw of the bow.  
   
   
       10 . A combination as defined in  claim 6:   in which each of the power units of the compound bow comprises a power cam and an anchor, both rotatable with the associated string cam; and    the unit's motion/force transmitting component: (a) is trainable around the power cam as the bow is drawn, and (b) has an end affixed to the anchor.    
   
   
       11 . The combination of a compound bow and a bow string for drawing the bow and for launching an arrow nocked on the bow string when the bow string is subsequently released, the compound bow comprising: 
 a riser;    first and second string cams so rotatably fixed relative to opposite ends of the riser that the distance between the axes of rotation of the string cams remains essentially unchanged as the bow is drawn and as an arrow is propelled from the bow when the bow string is subsequently released; and    the bow string being enabled to draw the bow and to launch the arrow when the bow string is subsequently released.    
   
   
       12 . A combination as defined in  claim 11  wherein: 
 the bow string is so connected between and fixed at opposite ends to the rotatably mounted string cams that displacement of the bow string to draw the bow effects counter rotation of the string cams; and    the bow further comprises cam-coupled power unit components which are elastically deformable by rotation of the string cams when the bow is drawn to store potential energy that is convertible to arrow propelling kinetic energy when the bow string is released.    
   
   
       13 . A combination as defined in  claim 12  in which the power units of the compound bow are housed in and shrouded by the riser of the bow.  
   
   
       14 . A combination as defined in  claim 12  in which the power units of the compound bow each comprise a mechanical arrangement for so adjusting the load on the elastically deformable component of the unit as to change the force required to effect a full draw of the bow.  
   
   
       15 . The combination of a compound bow and a bow string: 
 the compound bow comprising a riser and first and second string cams rotatably mounted to opposite ends of the riser;    the bow string extending between the string cams, and opposite ends of the bow string being fixed to the string cams such that the cams are counter rotated in: (a) first directions as the bow string is pulled to draw the bow, and (b) in second, opposite directions when the string is subsequently released to propel an arrow from the bow; and    the bow further comprising a timing mechanism for synchronizing the rotations of the string cams, the timing mechanism comprising:    first and second timing wheels respectively rotatable with the first and second string cams; and    a flexible, generally inextensible component which extends between and is fixed to the first timing wheel and to the second timing wheel.    
   
   
       16 . A combination as defined in  claim 15  wherein the flexible timing mechanism component has a figure 8 configuration.  
   
   
       17 . A combination as defined in  claim 15  in which the compound bow has at least one feature for holding the flexible timing mechanism component out of the path followed by an arrow as the arrow leaves the bow.  
   
   
       18 . A combination as defined in  claim 15  in which: 
 each of the first and second timing mechanism wheels has a surface around which the flexible timing mechanism component can wrap as the bow is drawn; and    the timing mechanism further comprise an idler so positioned relative to each of the first and second timing wheels as to change the path of the flexible timing mechanism component in a manner which increases the angle through which that component can wrap around the timing wheel at full draw of the bow and keeps rotation of the timing wheel from interfering with the draw of the bow.    
   
   
       19 . A compound bow which comprises: 
 a riser;    first and second string cams rotatably mounted to opposite ends of the riser for counter rotation in first directions as the bow is drawn and in second, opposite directions when an arrow is shot from the bow;    string cam-associated power units which are mounted at opposite ends of the riser; and    a mechanical timing mechanism for synchronizing the counter rotation of the first and second string cams in their first directions and in their opposite, second directions.    
   
   
       20 . A compound bow as defined in  claim 19  wherein each power unit includes an elastically deformable component and a motion/force transmitting mechanism so connecting the elastically deformable component to the associated string cam that: (a) rotation of the string cam in its first direction as the bow is drawn so deforms the elastically deformable component as to store potential energy in that component, and (b) subsequent rotation of the cam in its opposite direction when the bow string is subsequently released and 
 frees the elastically deformable power unit component for restoration to its rest configuration with a concomitant conversion of the potential energy stored in the component to arrow propelling kinetic energy.    
   
   
       21 . A compound bow as defined in  claim 19  wherein the riser of the bow is of rigid construction and has: 
 an elongated center section with a hand grip intermediate its ends; and    first and second arms, each arm being integrated at one end thereof with an end of the riser section, each arm being oriented at an angle relative to a bow string side of the riser center section and terminating in a free end spaced from the bow string side of the riser;    the string cams being rotatably mounted to the free ends of the riser arms.    
   
   
       22 . A compound bow as defined in  claim 19  wherein the motion/force transmitting component of the power unit comprises: 
 an anchor mounted to the associated string cam for rotation therewith;    a power cable connected between the elastically deformable power unit component and the string cam-mounted anchor; and    a power cam so mounted to the string cam that the power cable can wrap around the power cam as the bow is drawn and the string cam consequentially rotates in its first direction.    
   
   
       23 . A compound bow as defined in  claim 22  wherein: 
 the elastically deformable power unit component has a free and an anchored end; and    one end of the power cable is connected to the free end of the elastically deformable component.    
   
   
       24 . A compound bow as defined in  claim 19  wherein the timing mechanism for synchronizing the rotations of the string cams comprises: 
 first and second timing wheels respectively rotatable with the first and second string cams; and    a flexible, generally inextensible component which extends between and around and is fixed to the first timing wheel and the second timing wheel.    
   
   
       25 . A compound bow as defined in  claim 24  wherein the flexible timing mechanism component has a figure 8 configuration.  
   
   
       26 . A compound bow as defined in  claim 24  in which the compound bow has at least one feature for holding the flexible timing mechanism component out of the path followed by an arrow shot from the bow.