Control system for a load handling clamp

Abstract

A control system for a load-handling clamp includes first and second load-engaging surfaces for selectively gripping and releasing a load disposed between said surfaces. At least one of said surfaces is selectively movable toward the other by a hydraulic actuator. At least one fluid valve assembly variably regulates a maximum hydraulic clamping pressure capable of causing the actuator to move one of the surfaces toward the other in a load clamping movement. Preferably, a load geometry sensor produces an electrical effect that varies as a function of the geometric profile of the load. A data receiver preferably also obtains load identification information related to at least one characteristic of the load, other than the load's geometry. A controller, in response to the data receiver and load geometry sensor, operates to control the valve assembly's regulation of the maximum hydraulic clamping pressure. In order to prepare for the load clamping movement, the controller is preferably also capable of enabling the actuator to move one of said surfaces toward the other in an initial clamp closing movement at a maximum hydraulic closing pressure greater than the maximum hydraulic clamping pressure. Thereafter the controller enables the load clamping movement at a pressure level substantially no greater than the maximum hydraulic clamping pressure.