Pilot-operated flow controlling directional control valve with copying spool
US5005467A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 17, 1988 |
| Grant date | Apr 9, 1991 |
| Priority date | — |
| Expiry date | May 17, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/87185
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
Device in a hydraulic power system connected to a load driving hydraulic motor (18; 32), comprising a pilot controlled flow regulating directional valve (1; 29) for alternative connection of the service ports of the motor (18; 32) to a pressure medium source and a tank. The directional valve (1; 29) comprises two opposite and by a pilot pressure activatable activating means (3, 4), and a pilot pressure means (84) is arranged to pressurize and activate the activating means (3, 4), alternatively, and drain one of the activating means to the tank through a flow restriction (5, 7) at activation of the other activating means (3, 4). The power system comprises at least one control flow circuit (10-12; 72-83; 37-44) which communicates with one of the activating means (3, 4), and a valve means (11, 12; 71; 31) which is arranged to accomplish a flow through the control flow circuit (10-12; 72-83; 37-44) in relation to the load pressure on the motor such that the counter pressure from the flow restriction (5, 7) generates a compensating force in relation to the load pressure on the motor on the non-activated activating means (3, 4).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.