Fluid-actuated clamping apparatus and circuit

US3990594A · kind A · utility

Assignee

• Cascade Corporation · US

Inventors

• John E. Olson · Portland, US
• Richard D. Seaberg · Vancouver, US

Key dates

• Filing date: Aug 29, 1975
• Grant date: Nov 9, 1976
• Expiry date: Aug 29, 1995

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F15B2211/78
• WIPO field: Handling
• WIPO sector: Mechanical engineering

Abstract

A load-clamping apparatus wherein the loaded and unloaded condition of the clamping arms (respecting their contacting an external body) is automatically sensed, and used to determine the type of fluid connections which exist at any given moment between fluid motors that move the arms. With the arms moving toward one another, so long as the movement of neither arm is hindered by an external body, a series connection exists between the motors producing relatively high-speed low-power relative movement between the arms. When such hindering occurs, a parallel connection is produced which results, during clamping, in lower-speed higher-power relative movement between the arms. One embodiment of the invention takes the form of apparatus capable simply of producing relative movement between clamping arms toward and away from one another to clamp and release a load. Another embodiment enables this action, plus reversible, common-direction side-shifting of the arms.