Hoist-suspended grab for rubbish etc. - has hoist motor briefly cut in after cutting out grab motor under excessive pressure

摘要

The suspended grab is lifted and lowered by a hoist motor, being equipped with switchgear cutting out the grab closing motor when a predetermined closing pressure is exceeded. On cutting out the grab motor, this switchgear briefly cuts in the hoist motor, and it can be incorporated in the pressure supply to a hydraulic grab, or alternatively connected to the slipping clutch in a mechanically-operated one. A time-lag relay can be incorporated in the switchgear, actuated by a pressure switch in the hydraulic grab actuating system, and delaying cutting out the grab motor after maximum closing pressure is reached.