Overload protection device.

摘要

An overload protection device adapted to be secured between a robot arm and a tool, comprises a floating piston (20) within a cylinder (18). Hall effect sensors are spaced around the cylinder wall and mating magnets are spaced around the piston wall. The cylinder is pressurized to axially align the piston with the cylinder and to position each magnet in alignment with a sensor. When an overload occurs involving either the robot arm or the tool, the magnets are moved relative to the sensors causing the sensors to signal for depressurization of the cylinder. An electronic system responsive to the Hall effect sensor signals lights an "overload" LED and triggers a timer circuit which generates a timing pulse of fixed duration. During the duration of the timing pulse, the robot is de-energized. A red LED is illuminated indicating the robot system is not ready to be operated. Also, a solenoid valve is energized, cutting off the pressure to the cylinder.