Locking cylinder
US6575678B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 2, 2001 |
| Grant date | Jun 10, 2003 |
| Priority date | — |
| Expiry date | Aug 2, 2021 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF15B15/264
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A hydraulic cylinder having an integral self-contained locking mechanism is described. A locking cylinder includes a housing that contains a screw shaft and a rod/piston assembly. A rod end of the rod/piston assembly can be connected to one load and the end cap, which is located opposite to the rod end, can be connected to another load. The two loads may be two levels of a car trailer. During an extension stroke the screw shaft is released from a locking mechanism inside the housing, allowing the screw shaft to rotate freely. The rod piston assembly, which is in threaded engagement with the screw shaft, moves freely along a longitudinal axis as a pressure is applied, and it unscrews from the screw shaft. When the assembly reaches a desired or maximum extension, the pressure is removed. The piston retracts slightly until the screw shaft re-engages with the locking mechanism. During a retraction stroke a pressure releases the screw shaft from the locking mechanism, maintains it in the unlocked position and allows the screw shaft to rotate freely. In this motion, the assembly screws onto the screw shaft thereby retracting the locking cylinder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.