Safety Device Hoist Weight limiter for Upper Limit:
It is also called hook height limiter. It is generally installed on the head of the boom. When the hook slips to the limit position, it will lift the lever. Press the lower limit switch to cut off the circuit and stop. When reclosing, the hook can only be lowered.
Scope of use:
The lifting height limiter can be installed beside the winch or in the distribution cabinet. During installation, the fine steel wire rope or nylon rope shall be fixed firmly through the small hole at one end of the convex concave type tension bar, and the other end shall be fixed on the top of the cage. The lead of the travel switch is connected to the AC contactor of the distribution cabinet.
How it works:
When the cage of the construction elevator moves upward, the small roller on the travel switch is in the concave point of the convex concave type brace - energized position. In case of mechanical failure or operator's misoperation of the elevator, the cage will rise to the limit height, i.e. at the set height of the lifting height limiter, because the cage crossbeam affects the thin steel wire rope and convex concave tension strip, at the same time, the small roller on the travel switch will move up to the convex part of the convex concave tension strip due to the external force, and the small roller will move from the electrified position at the opening point to the convex point, so that the travel switch will be disconnected. Power on, cut off the upward power supply, stop the winch motor, and stop the cage. Manually lift the convex concave type brace of the height limiter to reset the small roller on the travel switch from the convex point to the power on position of the concave point, so as to start the cage.
The device complies with the requirements of safety rules for construction lifts. When the operation of the cage exceeds the set height, the device can quickly cut off the main power supply and stop the cage. It is emphasized in the specification that the automatic reset type is not allowed to be used for the SS type elevator for both people and goods. The safety device is non automatic reset type. Cut off the main power supply during operation, reset manually after operation, restore the power on state, make the elevator operate normally, and effectively prevent the occurrence of "roof fall" accident.
Conclusion:
The lifting height limiter is novel and simple in structure, safe and reliable in automatic control, and can effectively control the occurrence of "roof falling" accident only by pulling once in case of accident. The device is suitable for construction elevator, gantry, derrick and other vertical transportation equipment. |