摘要 |
An overspeed brake mechanism for a storage and retrieval vehicle (SRV). The brake mechanism includes wedges acting between a brake block attached to the load carriage of the SRV and the mast of the SRV. The wedges are biased into engagement with the mast and are held out of engagement under normal operating conditions by electromagnets which apply an attractive force to the wedges, the electromagnets being de-energized by a control system responsive to an overspeed signal from a tachometer generator on the load carriage and having its input member in engagement with the mast. In accordance with a further aspect of the invention, permanent magnets imbedded in the wedges bias the wedges into light contact with the mast to insure that there will be no lost motion between the wedges and the mast when the brake is activated.
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