Patent ID: 7553120

Claim:
A hydraulic grip control unit, comprising: a hydraulic grip control device; a striker arm; a hydraulic fluid source under pressure; hydraulic cylinders; gripping arms driven hydraulically to seize loads while cooperating with said striker arm, said control device being connected hydraulically between said hydraulic fluid source under pressure and said hydraulic cylinders to form a closed supply circuit, each of said hydraulic cylinders driving one of said gripping arms, wherein said source feeds fluid to the cylinders, said cylinders being connected hydraulically in parallel, said control device including a flow divider connected along said supply circuit between said source and said cylinders such that said flow divider apportions the flow of the circuit between the cylinders in parallel, said flow divider having a nominal flow, said nominal flow of said flow divider being less than a nominal flow of the control device, said control device including a by-pass circuit connected in parallel to said flow divider, said by-pass circuit having an operative configuration and a non-operative configuration, said fluid flowing through said by-pass circuit and said flow divider in said operative configuration, said fluid not flowing through said by-pass circuit in said non-operative configuration, said control device including automatic by-pass circuit piloting means for switching said by-pass circuit to said non-operative configuration when the flow required by the supply circuit is substantially lower than the nominal flow of the flow divider and for switching said by-pass circuit to said operative configuration when said required flow is substantially greater than the nominal flow of the flow divider.