Multiple pulley sheave assembly with retainer pulleys
OwnerShale J. Niskininventor
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Abstract
Disclosed is a multiple pulley sheave assembly for supporting a cable comprising a plurality of pulleys, including a center pulley, mounted in an arcuate path on a support frame; a pair of retainer pulleys for keeping the bend of the cable constant around the center pulley; a cable monitor coupled to the center pulley for measuring the tension, footage, and cable speed; counter-balancing weights positioned above the support frame and rigidly connected thereto; and a suspension arrangement, connected at the center of the assembly, for providing rotation of the assembly about two perpendicular axes of rotation, whereby the cable stays within a plane defined by the arcuate path.
Claims5
A sheave assembly for supporting a cable, comprising:
- a support frame;
- a plurality of cable-receiving pulleys for receiving the cable comprising at least two outer pulleys and a center pulley positioned therebetween, each of said cable-receiving pulleys being rotatably mounted to said support frame along an arcuate path with their axes of rotation being substantially perpendicular to a plane containing said arcuate path;
- a pair of retaining pulleys being rotatably mounted to said support frame with their axes of rotation being substantially perpendicular to said plane, said retaining pulleys being positioned immediately adjacent said cable on the side of said cable opposite that side which is adjacent to said cable-receiving pulleys, one of said retainer pulleys being on one side of said center pulley and the other retainer pulley being on the opposed side of said center pulley;
- cable monitoring means operatively coupled to said center pulley for measuring the tension of said cable;
- whereby the bend of said cable remains substantially constant regardless of the direction of the ends of the cable extending from said sheave assembly, said cable monitoring means includes means for slidably mounting said center pulley to provide movement of said center pulley in a direction substantially angled with respect to said arcuate path at said center pulley and strain measuring means operatively coupled to said means for slidably mounting said center pulley for measuring the force applied by the cable to said center pulley in said direction substantially angled with respect to said arcuate line, whereby the force is used to determine the line tension of the cable, wherein said arcuate path of said cable-receiving pulleys has an increasing rate of curvature as the path extends outward and downward from its center.
Dependencies are inferred from the claim text.