Device for holding a stem of a hydraulic cylinder in position, and method for unblocking and blocking a secondary check valve of the device
US12140165B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 16, 2021 |
| Grant date | Nov 12, 2024 |
| Priority date | — |
| Expiry date | Jul 28, 2041 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF15B2211/8757
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A device for holding a hydraulic cylinder stem in position includes a hydraulic block having series-connected primary and secondary check valves. The latter includes a secondary control stem having a secondary valve body and a seal. A first throttle upstream and a second throttle downstream are closed in a secondary control stem closed position where the seal tightly blocks the secondary check valve, each throttle having a tiny throttle closing gap, preferably 0.1 mm or less. The control stem can move axially into an intermediate position where the throttles remain closed, that is, have a tiny closing gap, but valve body and seal are lifted from a secondary valve seat. The control stem can be moved further into an opening position where the throttles are open, each having an opening gap much larger than the closing gap, and the valve body and seal are lifted from the valve seat.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.