The safety devices of the construction hoist include damped rope break protection device, hand brake brake, door hook safety insert, cage door interlock switch, rope break switch, upper and lower limit switches, upper and lower limit switches and spring-type buffer devices on the base . Damping type broken rope protection device When the wire rope driving the cage is loose or broken, the brake oblique block inlaid with non-metallic friction material is lifted up under the action of the spring, and it frictions with the guide rail frame to achieve braking and stop the cage On the rail rack. When the steel wire rope driving the cage is tensioned and pulled upward, the pressure generated by the brake ramp on the guide rail is eliminated and it returns to the original position. There should always be a gap between the brake ramp and the seamless steel pipe of the guide rail to ensure that the cage can move up and down freely. The brake ramp and the slideway should be regularly refueled and moved frequently to prevent rust and ensure the flexibility of movement.

Hand brake brake device.

A hand brake device is installed on the hanging cage. When the brake handle is pulled, the brake ramp is lifted and generates friction with the seamless steel pipe of the guide rail frame to realize braking. The hand brake is used to ensure safety when the hoisting cage is stopped on the rail frame and the installer is installing or removing the rail frame.

The door hook safety plug is equipped with a safety plug mechanism on the cage. When the cage door is opened, the insert block is automatically inserted into the guide rail frame to ensure that the cage can still stop on the guide rail frame when the wire rope is loose or broken. When the cage door is closed and the door hook is locked, the insert block is retracted and the cage can move up and down freely. The device works after the hoisting cage reaches the working surface before the personnel enter the hoisting cage, so that the hoisting cage is stabilized on the guide rail frame to ensure the safety of the personnel loading and unloading materials. The cage door interlock switch is equipped with a cage door interlock switch on the cage, which prevents the cage from starting when the cage door is open. Rope break switch When the rope is broken, the switch immediately cuts off the control circuit, the brake is applied, and the hoist stops rotating.

The upper and lower limit switches are installed on the guide rail frame and the hanging cage and are of automatic reset type. When the cage is raised, in order to prevent misoperation from causing the cage to fall roof, an upper limit switch is installed at a distance of about &% from the tower cap. When a misoperation occurs, the hoisting cage ramp first hits the travel switch, cuts off the control circuit, and stops the hoist. When the hoisting cage is lowered, a lower limit switch is provided in order to prevent misoperation from causing disordered ropes of the hoist. When a misoperation occurs, the hoisting cage ramp will first collide with the lower limit switch, cut off the control circuit, and make the hoist automatically stop running. Therefore, it is ensured that the wire rope will not be slack, and the wire rope of the hoist drum is always arranged neatly.

Both the upper and lower limit switch type construction hoists are equipped with limit switches, whose function is that when the hoisting cage runs beyond the limit switch and overtravel, the limit switch will cut off the main power supply and stop the hoisting cage. The limit switch is a non-automatic reset type, and the cage can only be restarted by manual reset after the action. The limit switch is installed on the rail frame and the hanging cage. When the upper limit switch is in normal working condition, the overtravel distance between the upper limit switch and the upper limit switch is. If the upper limit switch control system fails, after the overtravel distance, the hoisting cage ramp collides with the upper limit switch, the total power supply of the entire elevator is cut off, and the hoist stops working to ensure the safety of the elevator. In the normal working state of the lower limit switch, before the cage touches the buffer, the lower limit switch will act first, that is, the installation position of the lower limit switch is between the lower limit switch and the buffer. If the lower limit switch control system fails, after a certain overtravel distance, the hoisting cage ramp collides with the lower limit switch, the total power supply of the entire elevator is cut off, and the hoist stops working to ensure that the wire rope is not slack.

The spring buffer device is a device installed on the elevator base to reduce the shock. When the lower limit switch fails, the cage continues to descend, it can absorb the impact kinetic energy of the cage; under normal working conditions, the spring-type buffer device does not work. At present, some manufacturers do not pay much attention to the role of the safety device of the construction hoist. When products are manufactured, they lack safety devices such as cage door interlock switches, rope break switches, upper and lower limit switches, and the products are inherently inadequate when they leave the factory; some construction units do not understand the role of the safety devices of the type construction elevator or have a weak safety awareness, so they do not use them. Pay attention to the maintenance and maintenance of various safety devices, so that some safety devices are damaged, lost or unable to work normally. In short, both the manufacturer and the construction unit must raise their safety awareness, correctly understand the role of various safety devices of the construction hoist, and ensure that the safety devices are complete and intact in the factory and in use, so as to ensure the safe operation of the construction hoist.