Patent · US Expired

Gas spring

US4045008A · kind A · utility

73Cited by
8References
6Claims
0Family size

Assignee

Inventor

Key dates

Filing dateApr 13, 1976
Grant dateAug 30, 1977
Priority date
Expiry dateApr 13, 1996

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF16F9/36
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

A gas spring, particularly adapted as a lifting means for hatch backs or trunk lids of motor vehicles, comprises a piston rod acting as a displacement piston, a housing cylinder containing a compressed gas, a guide piston near one end of the piston rod and in slidable relationship with the interior of the cylinder housing, characterized in that the piston rod is provided with an extension projecting beyond the guide piston, the closed end of the cylinder housing having a complementary receptacle for the piston rod extension, whereby when the piston rod is fully retracted into the cylinder housing, the extension enters the complementary space in the housing in a sealing manner, a valve being provided to permit the escape of fluid from the space as the extension passes thereinto, whereby the force acting to extend the piston rod is reduced to zero or nearly zero in the vicinity of the fully retracted position of the piston rod.

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