05040520 is referenced by 23 patents and cites 13 patents.

Composite bowstring and take-up string cam pulleys are carried by the tip portions of a compound archery bow limbs extending oppositely substantially symmetrically from a handle with the bowstring connecting the composite cam pulleys and take-up strings extending from each composite pulley to the opposite bow limb. Each composite cam pulley is composed of a generally elliptical bowstring pulley section having a major axis passing through its portions of substantially greatest length and a generally elliptical take-up string pulley section having a major axis passing through its portion of substantially greatest length, which pulley sections are integrated in parallel side by side relationship with planes containing their major axes substantially perpendicularly intersecting. The effective bowstring lever arm of the bowstring pulley section is small and substantially constant during increase of the draw force to at least 90 percent of the maximum draw force while the bowstring nocking point is displaced less than 40 percent of the total displacement during draw and the bowstring lever arm then increases substantially linearly while the draw force remains at a substantially constant maximum value over at least a third of the total bowstring nocking point displacement during draw of the bowstring. The ratio of bowstring draw arm to take-up string draw arm is substantially constant during the draw force increasing phase of the draw.

Title
Limb tip cam pulley for high energy archery bow
Application Number
438204
Publication Number
5040520
Application Date
February 25, 1988
Publication Date
August 20, 1991
Inventor
David J Nurney
12213 Densmore Ave. N., Seattle, 98133
WA, US
Agent
Ward Brown
Robert W Beach
IPC
F41B 5/10
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