Gary Otis Shaffer

US Patent:

41218680, Oct 24, 1978

Filed:

Mar 14, 1977

Appl. No.:

5/777145

Inventors:

Ray E. Pierce - Portland OR
Gary J. Shaffer - Beaverton OR
Roger L. Belanger - Fort McMurray, Alberta, CA

International Classification:

B66C 142

US Classification:

294116

Abstract:

A gripping apparatus for lifting objects remotely utilizing three pivotally mounted gripping arms driven by integral cam followers located on extremities and roller grasping means located on their opposite extremities. The cam followers are carried in tracks, located in a rotatable can which moves the gripping arms and rollers inwardly or outwardly upon rotation of the cam by a remotely controlled bi-directional electric motor. A positioning cone centers the gripping arms over the load to be gripped thereby preventing an unsymmetrical grip which could cause inadvertant or premature release of the load. A bottom limit switch senses tension in the cables upon which the apparatus is suspended to prevent activation of the gripping fingers unless the apparatus is fully lowered, and an inertia switch senses rotation of the apparatus for preventing excessive torque on the cam by reactive torque of the motor which could cause the entire apparatus to twist.