Broken rope protective device of upright lift gate

The invention discloses a broken rope protective device of an upright lift gate. The broken rope protective device comprises a bearing shaft, one end of the bearing shaft is connected with the upright lift gate, and the other end is equipped with a mounting substrate, two surfaces of the mounting substrate are respectively equipped with a broken rope triggering mechanism and a track clamping executive mechanism. The invention adopts a bearing shaft as a protected object to connect with the device, the gravity of the lift gate is used for braking, and the spring force is mainly used for triggering the broken rope; and therefore, the braking force is in proportion to the gravity of the lift gate directly, that is, the heavier the lift gate is, the greater the braking force is. The broken rope protective device is reliable in braking, and compact in structure. By adopting a pair of lever mechanisms in the broken rope triggering mechanism in the invention, the broken rope protective device is flexible in action and reliable. A rack mechanism and a gear mechanism are applied to the track clamping executive mechanism to convert the linear motion into the rotary motion; and the clamping force is amplified by using a method for reducing a clamping cam force arm, so that the broken rope protective device has a compact structure, and high action reliability.