Abstract: A chain block comprising a load sheave winding up a load chain, a hand wheel arranged on one side of the load sheave and rotatable in one of a normal direction and a reverse direction in response to the manual operation of a hand chain, a pinion shaft inserted through the load sheave along the center axis of the load sheave in a manner allowing the load sheave to be freely rotatable thereabout, one end of the pinion shaft screwed into the center of the hand wheel and the other end of the pinion shaft including a spindle gear, a reduction gear composed of a small-diameter gear and a large-diameter gear, the large-diameter gear in mesh with the spindle gear, a main shaft gear, in mesh with the small-diameter gear, transferring a torque of the reduction gear to the load sheave.

Abstract: A chain block comprising a load sheave winding up a load chain, a hand wheel arranged on one side of the load sheave and rotatable in one of a normal direction and a reverse direction in response to the manual operation of a hand chain, a pinion shaft inserted through the load sheave along the center axis of the load sheave in a manner allowing the load sheave to be freely rotatable thereabout, one end of the pinion shaft screwed into the center of the hand wheel and the other end of the pinion shaft including a spindle gear, a reduction gear composed of a small-diameter gear and a large-diameter gear, the large-diameter gear in mesh with the spindle gear, a main shaft gear, in mesh with the small-diameter gear, transferring a torque of the reduction gear to the load sheave.

Abstract: The most commonly used spring type chain lever hoists suffer from a major drawback in that, if the chain is drawn quickly over the load sheave while it is set for free running operation, the brake will automatically be applied and the free running movement terminated. Similarly, if a light load is suspended from the chain, the weight of the load may be insufficient to activate the brake with the result that the load will be wound down dangerously quickly, leading on occasion to accidents. The present invention is designed to resolve these potentially fatal flaws by enabling a hub, which screws freely onto a spindle in the conventional manner, to be rotated through a few degrees into a prescribed lock position relative to the spindle and then locked there either temporarily or permanently as required.

Abstract: The most commonly used spring type chain lever hoists suffer from a major drawback in that, if the chain is drawn quickly over the load sheave while it is set for free running operation, the brake will automatically be applied and the free running movement terminated. Similarly, if a light load is suspended from the chain, the weight of the load may be insufficient to activate the brake with the result that the load will be wound down dangerously quickly, leading on occasion to accidents. The present invention is designed to resolve these potentially fatal flaws by enabling a hub, which screws freely onto a spindle in the conventional manner, to be rotated through a few degrees into a prescribed lock position relative to the spindle and then locked there either temporarily or permanently as required.