Patent · US Expired

Multi-chamber temperature compensated pneumatic counterbalance

US4408751A · kind A · utility

30Cited by
6References
36Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 24, 1981
Grant dateOct 11, 1983
Priority date
Expiry dateApr 24, 2001

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF16F9/52
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

A pneumatic, piston/cylinder counterbalance in which the counterbalance force is obtained by differential pressure across the piston and in which the force changes due to temperature are compensated by use of a variable volume cylinder having one or more auxiliary chambers separated by walls, each including a temperature responsive bi-metal disc valve normally acting as a check valve permitting flow into the auxiliary chambers but preventing flow out of the chambers except when the temperature drops to a predetermined value. In the multiple auxiliary chamber embodiment, flow into and out from each chamber is controlled by an associated bi-metal disc valve responsive to successively lower temperatures to enable a more linear stabilization of force output regardless of temperature.

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