Extend and retract control for fork lifts
US5011363A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 5, 1989 |
| Grant date | Apr 30, 1991 |
| Priority date | — |
| Expiry date | Dec 5, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T74/20201
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
A fork extension and retraction system for use with stockpickers automatically extends and retracts hydraulically extendable forks of a stockpicker when the load handler carrying the forks has moved to its extended position on the load side of the vehicle, and it also automatically retracts the forks if they have drifted from a home position before performing other fork related activities. Switches in the fork carriage assembly sense when the extendable forks are in the home position and near the home position. Other switches sense when the load handler assembly has reached its extreme positions on either side of the operator's platform. Still other switches are used to slow the traverse movement of the load handler assembly as it approaches its extreme positions, thus to cushion the shock of the load handler stopping. A control circuit senses the condition of these switches and controls the operation of both the load handle and the fork extension hydraulic system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.