SU99886A1 - Two-jib electric cantilever crane on rail - Google Patents

Description

One of the drawbacks of existing electric cantilever cranes on a roadway rail, equipped with overhead booms, is the laboriousness of installing overhead booms when driving the crane from the transport position to the working position. Existing fixtures for mounting booms (hydraulic jacks) do not provide adequate safety of work, and most importantly cause significant loss of time.

An onsivable two-jib electric cantilever crane of the type indicated above, intended for the installation of bridge span structures, is equipped with a mechanism for lifting the crane. This mechanism is formed by three polyspasts with transitional equalizing blocks from two polyspasts, placed at the ends of the frame, on the third one located between them. A round cable from the latter is wound onto the electric winch drum. For the mechanization of the lift, an additional hoist of an additional anti-swinging chain hoist is used.

The drawing shows the scheme of the spares of the lifting mechanism of the boom lift.

The boom lift mechanism consists of three pulley blocks 1, 2 and 3 with

transitional leveling bars 4 from the first two polyspasts / and 2 to the third 3.

The first two polyspasts are fourxKjDaTHbie; The upper two-roll blocks 5 are mounted on the end diaphragms of the boom of the crane, and the lower two-roll blocks 6 are mounted under the cross spreader base struts. The third horizontally located tackle, six times, is mounted between the guide channels attached to the struts and the supporting diaphragms of the base of the crane. The end of the traction rope of this pulley through the tapping rollers 7 and (directed to the electric winch 9.

The crane boom is mounted as follows.

The rear ends of the arrows, in the transport position, horizontally spread on the platforms, are raised a little with the help of screw arrow lifters, and the arrow assumes an inclined position. The platforms move to the base of the crane until the axes of the hinges of the bearing parts coincide, and the boom boom is lowered onto the supporting parts. The dead ends of the polyspasts / and 2 are thrown through the rollers of the blocks at the ends of the arrows and secured

to the cross strut base crane. Turning on the electric winch, the horizontal hoist 3 is pulled out and the booms are raised to the horizontal position (both together or separately). After installing the anchor hinges of the counterbalance boom, the cargo boom, if necessary, can be lifted into a tilted position by additional tightening of the horizontal chain hoist. After mounting the boom of the crane, the traction end of the horizontal chain hoist cable is wound from the electric winch, and the latter is used to lift the chain hoist.

Subject invention

Claims (2)

1. Two-jib electric cantilever crane on a rail track for installation of bridge span structures, equipped with overhead booms, so that, in order to use the electric winch of an additional tackle counterbalance boom for mechanization of boom lifting, the boom lift is formed by three tackle blocks with transitional equalizing blocks from two tackle blocks, spliced at the ends of the frame, onto the third one located between them, the pull cable of which is wound on the electric winch drum. 2. The form of the crane according to claim 1, characterized in that, for the convenience of placing the tackles, the two extreme tackles are arranged vertically and the third intermediate tackle horizontally.