SU749793A1 - Apparatus for lifting crane boom and varying its outreach - Google Patents

Description

(54) DEVICE FOR LIFTING AND MEASURING THE DEPARTURE OF THE ARROW OF A LOADING CRANE

one

The invention relates to cranes, and in particular to devices for changing boom length.

A device for lifting a boom of a load-lifting crane is known, comprising a winch and a chain hoist consisting of a fixed part and a movable part made of a main and intermediate cage 1.

A disadvantage of the known construction is the relatively large rope capacity and power of the winch.

The purpose of the invention is to reduce the cable capacity and winch power.

For this, the main and intermediate sleeves are connected by a bond that holds them when lifting the boom over a distance determined by

C UMKC-H, where C is the bond length;

LDmlks - the length of the chain hoist, corresponding to the greatest working departure of the AmAk boom;

H is the smallest distance between the intermediate cage and the fixed part of the chain block, and the fixed part of the chain block is equipped with guide stops and restrictive rollers interacting with the intermediate frame. FIG. 1 shows a general view of the crane 5 with the boom and the proposed device; in fig. 2 - a device for lifting and changing the boom; in fig. 3 - schemes for storing the rope of the chain hoist; in fig. 4 shows section A-A in FIG. 2 on the chain hoist; in fig. 5 - polyspast, side view; 10 in FIG. 6 is a section BB in FIG. 5, front view of the blocks of the fixed part.

The device I for lifting and changing the reach of the boom 2 of the crane 3 contains a winch 4 and a polyspast 5 consisting of jetted by a rope 6 movable 7 and fixed 8 parts connecting the boom 2 to the platform 9 through the slewing boom 10 and the pull 11. The movable part 7 of the chain hoist is made of a main 12 and an intermediate 13 clips connected by a link 14, a push-up spring 15 to the slewing boom 10.

Claims (1)

The main yoke 12 contains blocks 16, which are fixed on the axis 17 of the swivel lug 10, and the intermediate yoke 13 contains blocks 18 on the axis 19, having landing necks 20 at the ends. The stationary part 8 contains blocks 21 mounted on the axis 22, which is fixed on the platform 9, and blocks 23 mounted on axis 24 mounted in lugs 25 rotatably around axis 22. On lugs, there are directional lugs 26 for intermediate cage 13 and restrictive rollers 27. Let us call sector. " the working area in which the boom overhang is changed with the load; the UZ sector is the mounting area corresponding to the boom lift during installation. Sectors set modes of operation and geometrical parameters of the device. The length of the connection C is determined from the conditions С С, where LА, „;, K (is the length of the chain pulley corresponding to the greatest AMLS flight during the crane operation; H is the smallest distance between the intermediate frame 13 and the eyes 25 of the fixed part 8 The boom initially rests on the ground and when the winch 4 is turned on, the boom 2 begins to lift, and the link 14 is in the tensioned position. The lifting speed is determined by the multiplicity of the pulley 5, which is equal to the number of branches of the rope 6, between the moving 7 and stationary 8 parts. As the boom rises, the distance between these parts of the tackle decreases. When moving the jib from sector J to a, the intermediate casing 13 is fixed in guide guides 26 by necks 20, which reduces the multiplicity of the tacker by eliminating the branches of the rope between blocks 18 and 23. The rate of change of the overhang of the boom in the working area is determined by the number of branches of the rope between blocks 16 and 21 and considerably exceeds the rate of its lifting in the mounting zone. As a result of decreasing the distance between the main 12 and the intermediate 13 yoke, the link 14 is loosened and pulled by the spring 15 to the swivel 10, and the lugs 25 with the intermediate yoke 13 tend to rotate relative to the axis 22 under the force of a branch of the rope connecting the main the yoke 12 with the block 23. The rollers 27 rest on the rope 6 and restrict the rotation of the lugs, excluding the contact of the fixed parts with the rope. Apparatus of the invention for lifting and changing the overhang of a lifting crane, comprising a winch and a polyspast consisting of a fixed part and a lifting part made of a main and intermediate cage, characterized in that, in order to reduce the cable capacity and power of the winch, the main and intermediate cage are connected by a bond that holds them when the boom is raised at a distance determined from the condition: С b {A) adks-H where C is the length of the connection; Hl) of the polyspast corresponding to the largest working reach of the boom; H is the smallest distance between the intermediate cage and the fixed part of the chain block, and the fixed part of the chain block is provided with guide stops and restrictive rollers that interact with the intermediate frame. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 455063, cl. B 66 C 23/82, 1971. S i 6 8