SU455063A1 - Jib crane - Google Patents

Description

The invention relates to a boom crane for lifting heavy loads during installation and handling operations.

Known jib cranes contain boom, jib jib with jib winch, two-legged stand with fixed jib boom mounted on it.

However, on large booms, when lifting a load on a jib winch, large tractive forces are transmitted, which require installing scarce bulky and expensive crane winches or Complex multiline boom polyspasts to install.

In the present invention, the additional tackle serves to reduce the forces in the boom winch when lifting and lowering the boom (with load and without load) and from work is not turned off, since one of the blocks of this tackle is always stationary and the other is moving.

The purpose of the invention is to reduce traction in the boom winch.

For this, the boom is connected to the upper movable block of the boom polyspast through an additional pulley block, the movable blocks of which are mounted on the traverse of the movable block of the boom polyspast, and the fixed blocks on the head end of the boom and on the two-leg stand

tackle mounted on the tip of the boom. In addition, the ends of the rope additional polyspast can be mounted on a two-leg rack.

FIG. 1 schematically shows a jib crane with an additional tackle; in fig. 2 - fastening of boom and additional polyspasts with a twofold decrease in pulling force; in fig. 3 - the same, with a threefold decrease in pulling force.

The jib crane contains platform 1, on which the boom 2, the two-leg rack 3, the cargo 4 and the boom 5 of the winch are mounted. For lifting the load, the cargo tackle 6 is used, and

to change the boom reach - boom 7 and additional 8 tackles. The jib nolispast 7 contains the lower stationary block 9 and the upper movable block 10 with a cross-beam 11. The movable blocks 12 of the additional polyspast 8 are attached to the tip of the boom 2, and the ends of the rope 13 of the additional polyspast are attached to the two-leg rack 3, or through roller link 14 on the two-leg rack to the boom 2. When securing the ends of the rope 13 of the additional tackle 8 on the tip of the boom 2 (see Fig. 2), the additional tackle consists of four threads, two of which are connected directly to the two-leg stand 3, and two are connected to the jib towing unit 7. During operationcrane on jib jib transmitted

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only half the effort from the boom r; ruz.) l; : t, as a result, doubled y: 1; eny1 aogs. y in the jib winch 5.

When the ends of the rope 13 are fastened to: an old polyspast 8; and a two-leg stand 3 (see Fig. 3) completes the longitudinal polyspast consists of six to 10 k and a third part of the force from the boom with a load is transferred to the boom. The boom winch 5 U. is mixed three times.

Subject invention

1. A boom speck, a carcass, a stre.tu, a boom polyspast with a boom winch, a double-sided pile with a fixed boom polyspast block attached to it, and with TCiM I also distinguish it, in order to reduce the joint force in the boom winch, boom connected to the upper movable unit of the boom of the polyspast through the additional polyspast, the movable blocks of which are set, ieni-.i on t 5A.U.T.Life block t.to:, og () nolisnasta. and non-movable blocks - on o1-olo: 5ke boom. hp pa bipedal stand, with one of the rope of the additional polysiast attached to the tip of the boom.

2. The jib crane: on item 1, different from ieM, that the ends of the rope are supplemented with an iolispast fastened on a two-leg stand.

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