Patent · US Expired

Automotive lift hydraulic fluid control circuit

US6189432A · kind A · utility

39Cited by
6References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 12, 1999
Grant dateFeb 20, 2001
Priority date
Expiry dateMar 12, 2019

Classification

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

Abstract

A hydraulic control circuit comprises a power unit, a central processing unit, at least one feedback sensor, a valve manifold, and two or more hydraulic lifting cylinders interconnected with miscellaneous hydraulic hoses and electrical wiring. Basic lifting is regulated by a flow divider unit configured to distribute a flow of pressurized hydraulic fluid pumped from a fluid reservoir through the valve manifold to each of the lifting cylinders during a lifting operation. To compensate for any imbalance between the lifting cylinders, the central processing unit monitors the movement of the lifting cylinders, and is configured to divert, through a three-way valve in the valve manifold, an additional portion of the pressurized fluid flow to a lagging lifting cylinder. During decent operations, the central processing unit extracts an additional portion of the fluid return flow through the three-way valve from a lagging lift cylinder, such that at all times during either lifting or decent operations, each lifting cylinder and a supported runway are disposed in a substantially parallel configuration.

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