Press safety guard control - has guard solenoid valve interlocked with clutch solenoid valve through cams and relays

摘要

The safety guards for eccentric presses are automatically controlled by a combined pneumatic and electric control system. An electrical interlock is provided between the valve which opens the air passage for the press clutch engagement cylinder, and the valve which opens the air passage for the actuating cylinders of the safety guards. This eliminates possible human errors in operating pedal-actuated safety guards. The solenoid valve for the safety guard cylinders in interlocked with the solenoid valve for the actuating cylinder of the eccentric press clutch. When the first valve is dead, the safety guards are down. The second valve is actuated by closing further switches. Turning of a cam from its top dead centre opens a switch so that a relay drops out and another relay is held ON.