Shut-off device for a fluid driven motor
US4492146A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 26, 1982 |
| Grant date | Jan 8, 1985 |
| Priority date | — |
| Expiry date | Jul 26, 2002 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB25B23/145
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
The present invention relates to a device for shutting off a supply of pressurized motive fluid to an associated fluid driven motor in response to a predetermined motor back pressure indicating a predetermined load on the motor. The device comprises a housing having a fluid inlet connected to a supply of motive fluid and a fluid outlet connected to supply pressurized fluid to the associated fluid driven motor. A passageway extends through the housing between the fluid inlet and the fluid outlet. A shut-off piston is slidably mounted with the housing and is shiftable to close the housing passageway and shut off the supply of pressurized fluid to the motor in response to a predetermined motor back pressure. An orifice of variable size is provided in the housing passageway and is utilized to reduce the pressure of the fluid supplied to the motor. The size of the orifice is controlled by a pilot piston slidably mounted within the housing and shiftable between a first and second position to vary the size of the orifice from a restricted to an open size. The pilot piston is shiftable in response to a predetermined motor back pressure to enlarge the orifice prior to the closing of the shu…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.