FAQ >> WALKING CRANE FOR OPERATION BY POWER OR HAND

WALKING CRANE FOR OPERATION BY POWER OR HAND

Fig. 52 represents a walking crane operated by power and consisting of a boom, rotating around a fixed column mounted upon an extended truck, which latter travels upon a suitable rail upon the floor. Power is utilized for hoisting and lowering, and for propelling the crane longitudinally upon its track. Cranes of this type are built of any desired capacity from r to io tons, and for operation either by hand or by power.

The base consists of two wrought iron girders united by riveting and carrying between them the truck wheels which support the crane. Rising from the center of the base is a cast iron col. umn, somewhat similar to that of the pillar crane shown on page 132, and revolving around this is the mast, consisting of two channel irons, united by suitable castings at top and bottom, and containing the rollers by which the mast is supported as it revolves. The boom is also formed of two channel irons, and from its outer end is suspended the running block, the chain from which passes over a sheave at the end of the boom to the hoisting gear attached to the mast near its head, the slack chain falling from this to a receptacle at the foot of the boom.

The mechanism of this crane, when operated by power, is arranged as shown in the engraving. Power is transmitted by a driving rope passing around a wheel on top of the vertical shaft forming the axis of the crane, this shaft thus moving continuously in one direction at a constant speed. By a series of Weston Disc Clutches, controlled by suitable levers within easy reach of the operator, the power is made available for hoisting and lowering, and for propelling the crane in either direction upon its track. Rotation of the crane is effected in the usual way by pushing or pulling the suspended load. The levers are so arranged that the operator may either walk beside the crane as it moves, or may travel upon it. The crane is supported longitudinally by the extended wheel base of the truck, and transversely by rails bolted to the roof or ceiling, between which travels the horizontal truck or guide frame attached to the head of the mast.

When arranged for operation by hand, the hoisting gear of this crane is similar to that of the pillar crane described on pages 133 and 134, and the longitudinal travel of the crane is effected by a separate crank, operating mechanism attached to the base.

The system of clutches employed is explained at page 41. Cranes of this type are adapted for use in machine shops, for setting work in the various machine tools and for transferring it from one tool to another, and also in erecting shops for transferring parts to the place of erection and for setting them in position. For work of this description these cranes are exceedingly convenient and economical.

Estimates will be furnished on receipt of information as to whether to be operated by hand or power, maximum load to be lifted, effective radius desired, length of longitudinal travel and height from floor to ceiling.

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