Since the hand hoist is operated by pulling the hand zipper, there must be a connection between the hand zipper and the lifting chain. First of all, manual pull hand zipper, hand zipper bite hand zipper wheel drive 5 teeth long shaft rotation; Then, the 5-tooth long shaft drives the sprocket, the sprocket bites the chain, lifting the weight; Finally, the sprocket is fitted to a brake consisting of pawl, ratchet and friction plate, which is called the brake system!