Patent · US Expired

Universal control system for hydraulic cylinders

US4777798A · kind A · utility

40Cited by
10References
23Claims
0Family size

Assignee

Inventors

Key dates

Filing dateSep 21, 1987
Grant dateOct 18, 1988
Priority date
Expiry dateSep 21, 2007

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF15B11/22
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

A universal control system for hydraulic cylinders to enable controlled increments of movement for varying uses including shaping members and lifting and lowering of loads. The lift control system is utilized to synchronize the raising or lowering of a load by, for example, four simultaneously-acting pump-operated hydraulic rams which have plural increments of movement. A sensor associated with the load adjacent each ram measures incremental movement of the load. A master controller controls the operation of the rams in accordance with the sensed increments and operates each pump simultaneously and independently until each pump achieves a preselected increment of movement of a ram, to maintain the load substantially level, followed by movement of all the rams through another increment of movement until the total lifting or lowering movement is achieved.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.