Page:Architectural Review and American Builders' Journal, Volume 1, 1869.djvu/625

From Wikisource
Jump to navigation Jump to search
This page needs to be proofread.

1869.] Merrick's Patent Safely Appliance for Hoisting-Cages. 501 ever the hoisting-rope or chain ceases to act, the counterbalance, rope comes into action and prevents disaster. In the engraving, A is the hoisting-cage or platform ; B, the lifting chain, attached by means of links, C, to the bell crank levers, D, having their fulcrum s at E, and provided at the other end with teeth cut to fit the racks in the uprights of the framing. The ropes suspending the counterbalance weights are attached to the levers, D, at points outside their ful- crums, and pass over grooved pulleys, F. The operation of the machine and its arrangements is apparent from an ex- amination of the illustration. So long'