Self-bleeding hydraulic cylinder
US5390586A · kind A · utility
Inventor
Key dates
| Filing date | Mar 28, 1994 |
| Grant date | Feb 21, 1995 |
| Priority date | — |
| Expiry date | Mar 28, 2014 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF15B21/044
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A self-bleeding multi-stage or single-stage hydraulic cylinder system is disclosed which automatically bleeds entrapped air from within the cylinder each time the cylinder is cycled. The self-bleeding structure preferably includes a fixed elongated tube mounted to the base plate of the cylinder, and an axially moveable elongated tube telescopically mounted on the fixed tube. A biasing compression spring forces the moveable tube upward to a predetermined extent when the cylinder is extended. Upon contraction of the cylinder, air trapped therein is purged or bled from the cylinder through the top end of the axially moveable elongated tube into a fluid reservoir. In the final stage of contraction of the cylinder, hydraulic fluid is forced through the fixed and moveable elongated tubes thereby forcing the remaining air trapped therein out of the cylinder and into the hydraulic fluid reservoir.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.