Hydraulic latch device
US4838298A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 16, 1988 |
| Grant date | Jun 13, 1989 |
| Priority date | — |
| Expiry date | Jun 16, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/2607
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
An hydraulic latch device comprises a housing having an inlet (14) for hydraulic fluid, an outlet (17) for hydraulic fluid, and first and second spool means (63,67; 62) slidably mounted in the housing and operable to control the flow of hydraulic fluid from the inlet to the outlet, each of the first and second spool means having resilient means (68;69) associated therewith and being operable to bias the spool means in one direction of sliding movement, the resilient means being arranged such that that associated with the first spool means determines the inlet pressure which places the device in a latched mode in which a first relationship is established between the inlet and outlet, and the resilient means associated with the second spool means determines the inlet pressure at which the device is placed in the unlatched mode in which mode a second relationship is established between the inlet and the outlet, with the latch pressure being higher than the unlatched pressure, and means provided to assist in maintaining the device in the latch mode by way of the first spool means (63,67) being stepped so as to provide first and second surfaces against which the inlet pressure can act, …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.