Mechanical movements, powers and devices; a treatise describing mechanical movements and devices used in construcive and operative mechinery and the mechanical arts, being practically a mechanical dictionary (1917)
Hiscox, Gardner Dexter, 1822?-1908 · New York : The Norman W. Henley publishing co. · leaf 347
1414. DIFFERENTIAL CHAIN-PULLEYBLOCK.—The chain sprockets, one on each side ofthe gear drum, run in different directions, allowing thesurplus chain to hang between the draft chains. Aneccentric on the hand-wheel shaft rolls a loose pinionaround the discs, causing them to move in oppositedirections… … 1415. DOVJBLE SCREW-GEAR HOIST. —Aright-and-left screw turns the chain sprockets in meshwith the lifting chain. Box & Co. model.
Mechanical movements
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