Vertical shaft operation locking device

A vertical shaft operation locking device comprises a locking circuit and further comprises safety doors arranged at a shaft mouth, a shaft bottom and transportation alley entrances of a vertical shaft, inductive switches are installed on the safety doors, and the inductive switches are connected into the locking circuit in series through normally-open relays. When each safety door is in a closed state, each inductive switch closes the corresponding normally open relay, and the lockout circuit is in an on state; and when any safety door is in an open state, the lockout circuit is in an open circuit state, and the cage stops running. According to the locking device, interlocking of operation of all the safety doors, the cradle and the cage is achieved. And when the cage is interlocked with the lifting signal, the cage position and the safety door corresponding to the cage position, the safety doors and the cradle corresponding to other cage positions cannot be opened. Once the safety door is opened, the lockin