Safety device for lifting apparatus

摘要

A safety device is provided for use with a lifting apparatus having a main lifting mechanism for lifting, lowering and supporting a load. The safety device includes a cylinder operatively connected to the lifting apparatus and capable of lifting, lowering and supporting the load supported by the lifting mechanism. The safety device further includes a counterbalance holding valve operatively connected to the cylinder for preventing the lowering of the load supported by the lifting apparatus except in response to the application of hydraulic pressure thereto.