Hydraulic strut for a motor vehicle
US5799759A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 7, 1997 |
| Grant date | Sep 1, 1998 |
| Priority date | — |
| Expiry date | Mar 7, 2017 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16F9/56
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A positioning element to position two objects which are movable in relation to one another includes a cylinder in which there is an axially movable piston rod with a piston. The piston sealingly divides the cylinder into two working chambers by a piston ring, each of the working chambers containing blocking medium. The sealing by the piston ring can be bypassed during an insertion stroke of the piston rod. The piston includes a piston base body and a valve element, the valve element being movable along the base body to open and close a flow connection between the working chambers. An external opening force can displace the valve element to open the flow connection and permit an automatic extension stroke of the piston rod. The valve element remains open during the extension stroke on account of the flow of blocking medium through the flow connection. The valve element can be displaced to close the flow connection in response to stopping the extension stroke of the piston rod to position the two objects. To restart the extension stroke of the piston rod, a greater external opening force can be required than was necessary to start the initial extension stroke of the piston rod.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.