Manual hoists (including manual chain hoists and hand lever hoists) as a simple and practical light and small lifting tool have many adverse consequences in use due to overloading work. In order to effectively avoid overloading, based on the original structure of the manual hoist, an overload protection device, the load limiter, is designed to improve the safety of the manual hoist. So what is his working principle?
The movable hoist load limiter is composed of a pressure regulating nut, a disc spring, a limit carrier, a bracelet wheel (reversing ratchet) and a brake nut, wherein the limit carrier and the brake nut are spline-fitted. According to the user's request, the manual hoist is set to the limit value when lifting, that is, the slip point. Adjusting the pressure regulating nut, the disc spring presses the limit carrier so that the outer tapered surface of the limit carrier and the inner tapered surface of the brake nut are closely adhered to the two tapered surfaces of the hand wheel (reversing ratchet) respectively, forming two pairs of friction When the load is increased, the load chain (or the handle) is pulled. If the load is greater than the limit load, the pull torque (hand pull torque) is greater than the load limit friction torque, and the taper surface slip warning Overload, if the load is less than the limit load value, it can work safely at this time.