Gap bridge constant with safety protection function

The utility model discloses a gap bridge constant with a safety protection function, which comprises a chain conveyor used for conveying smoke boxes, stools arranged on two sides of the chain conveyor, a pedal arranged above the chain conveyor, a switch arranged on each stool, a duplex control switch connected in series with the switches corresponding to the two stools, and a safety protection device arranged on the chain conveyor. The duplex control switch is sequentially connected with an alternating current contactor and a starter, the starter is connected with the chain conveyor and used for starting the chain conveyor, the alternating current contactor is controlled through the duplex control switch, starting and stopping of the starter are controlled, and then starting and stopping of the chain conveyor are controlled. According to the gap bridge constant with the safety protection function, the alternating current contactor is controlled through the duplex control switch so as to control starting and s