Pressure sensitive charging means for a steering system
US4100739A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 16, 1977 |
| Grant date | Jul 18, 1978 |
| Priority date | — |
| Expiry date | Sep 16, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S60/911
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
An improved pressure sensitive valving arrangement is provided for a power steering unit for a lift truck, and in particular for a battery powered lift truck. To the conventional implement valve is added an accumulator charging means which includes an additional valve, herein called a "blocking or control valve", which additional valve is downstream from the implement valve and which additional valve, when actuated, blocks the flow of fluid through the implement valve to thereby build up pressure for charging an accumulator. The blocking valve includes a blocking spool which operates against a pressure-actuated pilot plunger such that when the pressure in the accumulator reaches or exceeds a predetermined amount, the pilot plunger shifts the blocking spool to permit the fluid to again flow through the implement valve. The blocking spool is actuated by a force acting on a control member associated with the lift or tilt levers, or may be actuated independently by a mechanism responsive to reduced pressure in the accumulator. The pressure-responsive mechanism shifts the blocking spool to a blocking position to charge the accumulator whether or not one of the lift or tilt implement act…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.