Safety locking means for lift arms of straddle carriers
US4087013A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 2, 1976 |
| Grant date | May 2, 1978 |
| Priority date | — |
| Expiry date | Aug 2, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T292/1082
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
The vertical lift arms of a straddle trailer are equipped with toothed ratchet bars which move therewith as the lift arms elevate a load. Cooperating pivoted pawls on relatively stationary mounts are spring-biased toward locking engagement with the ratchet bars to safely lock the lift arms in elevated load-carrying positions. Pneumatic pawl operators under control of a switch in the tractor cab can withdraw the pawls from locking engagement with the toothed ratchet bars only when the load on the lift arms is relieved by the cable-hydraulic lift arm raising and lowering system of the straddle trailer. Hence, a fail-safe arrangement is provided should either the pneumatic or electrical systems of the trailer fail. The four customary lift arm locking units are synchronized to operate in unison. A load cannot be locked by the system when off-balance. The invention is applicable to either newly manufactured straddle carriers or those already in existence.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.