Image Number 2 for United States Patent #7980978.
A hoisting and lowering driving engagement multi-row chain is disclosed, in which bending of the connecting pins in the chain is suppressed to avoid fatigue failure. Additionally, the load carrying balance in the chain width direction is improved, and contact vibrations and contact noises generated between the chain and the hoisting and lowering sprockets are suppressed. Endurance of the bush in the chain is thereby improved. Bending of connecting pins is avoided by press-fitting bushes, through which connecting pins pass, into intermediate tooth plates. This also improves load carrying balance widthwise. Contact noises and vibrations between the bushes and sprockets are suppressed by providing bushes with a separate sprocket engagement portion having a larger diameter than the press-fitting portion of the bushes.