Electric motor-actuated load clamp with clamping force control

摘要

An electric motor-actuated load clamp for automatically-guided vehicles has clamp arms which are selectively opened and closed by a plurality of rotary electric motors connected to the clamp arms by ball screws. Clamping force is accurately controlled by regulation of current to the electric motors, any of a number of different predetermined clamping forces being selectively obtainable. During clamping of a load, the electric motors are energized only a small fraction of the time according to a time-sequenced clamping and reclamping procedure, clamping force being otherwise maintained by a one-way brake. Further control features ensure against inaccuracy and overclamping due to current in-rush, and against malfunctions which could cause safety hazards.