Pulley for compound archery bow
First Claim
1. An eccentric pulley for a compound archery bow, the pulley including means defining an axis of rotation eccentric to a pulley rim surface which extends at least partially around the circumference of the pulley, the rim surface defining therein first and second grooves extending at least partially along the rim surface of the pulley, the first groove being defined entirely in a plane normal to said axis, the second groove being spaced from said plane with the amount of such spacing varying over at least a portion of the length of the second groove, and rigging cable passage means defined through the pulley from a first selected location on the first groove to a second selected location on the second groove spaced circumferentially along the rim surface from the first location.
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Accused Products
Abstract
An archer'"'"'s compound shooting bow has rigging cables and pulleys arranged to eliminate torque on the limbs when the bow is fully drawn and to permit an arrow to fly true past the rigging when the bow approaches its rest condition. Each pulley has two grooves receiving an adjacent rigging cable. The grooves have variable separation at different locations along the pulley rim. Each pulley is mounted on a limb alongside the opposite rigging cable dead end. As to each limb, the connection of the opposite cable dead end and the location of the adjacent cable tensions are arranged, in respect to their magnitudes at full draw, to apply no net torsional moment to the limb about its torsional axis.
The separation between the pulley grooves corresponding to the rest condition permits arrow feathers to pass the rigging cables without contact, which is not true at full draw. The groove for the shooting string is normal to the pulley rotational axis. The other groove is substantially helical to the first groove.
The pulley is ring-shaped and is fabricated from an extrusion having an annular cross section.
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Citations
24 Claims
- 1. An eccentric pulley for a compound archery bow, the pulley including means defining an axis of rotation eccentric to a pulley rim surface which extends at least partially around the circumference of the pulley, the rim surface defining therein first and second grooves extending at least partially along the rim surface of the pulley, the first groove being defined entirely in a plane normal to said axis, the second groove being spaced from said plane with the amount of such spacing varying over at least a portion of the length of the second groove, and rigging cable passage means defined through the pulley from a first selected location on the first groove to a second selected location on the second groove spaced circumferentially along the rim surface from the first location.
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22. An eccentric pulley for a compound archery bow, the pulley including means defining an axis of rotation eccentric to a pulley rim surface which extends at least partially around the circumference of the pulley, first and second grooves defined in and extending at least partially along the rim surface of the pulley, rigging cable passage means defined through the pulley from a first location on the first groove to a second location on the second groove spaced circumferentially along the rim surface from the first location,
in use the first and second grooves being associated with, respectively, a shooting string end portion and a bus portion of a rigging cable of a compound archery bow, so that the shooting string end portion of the cable contacts the pulley rim surface at a first point of departure on the first groove and is reeved in the first groove to the first location to enter the rigging cable passage means, and the bus portion of the cable contacts the pulley rim surface at a second point of departure on the second groove and is reeved in the second groove to the second location to enter the rigging cable passage means, the first groove being defined entirely in a plane normal to the pulley axis of rotation, the second groove being spaced from the plane in a direction parallel to the axis of rotation with the amount of such spacing varying over at least a portion of the length of the second groove so that upon rotation of the pulley from a rest position to a full draw position, the second point of departure of the bus cable from the pulley rim surface moves parallel to the pulley axis of rotation relative to the first groove.
Specification