JPH078546Y2 - Boom telescopic device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a boom telescopic device such as a crane.

2. Description of the Related Art As shown in FIGS. 3 and 4, the second boom is installed in the first boom 1.
The 3rd and 4th booms 2, 3 and 4 are telescopically inserted one by one,
The first cylinder 5 is connected between the boom and the second boom 2, and the cylinder 6 is connected between the second boom 2 and the third boom 3.
The third and fourth booms 3, 4 are connected by connecting the extension boom 7 and the reduction rope 8 to the third boom 3 and the fourth boom 4 and extending and contracting the second cylinder 6. A device capable of expanding and contracting is known.

Problems to be Solved by the Invention In such a device, both ends of the extension rope 7 are connected to the tip of the second boom 2 by the holders 9, respectively, and a pair of sheaves 10, 10 provided at the tip of the third boom. And around the equalizer sheave 11 provided at the rear end of the fourth boom 4, and the third boom
When the boom 3 is extended, the extension rope 7 is pulled and the fourth
Since the boom 4 is extended, the fourth boom 4
Since the equalizer sheave 11 is built into the inside of the, it is necessary to make the fourth boom 4 large enough to accommodate the equalizer sheave 11, and since the fourth boom 4 becomes large, the entire boom becomes large and heavy, and the crane is suspended. The load is reduced accordingly, and the work of winding the extension rope 7 is also troublesome.

Both ends of the reduction rope 8 are connected to the rear end of the fourth boom 4, and a pair of sheaves 12, 1 provided at the rear end of the third boom 3 are connected.
It is wound around a sheave 13 provided at the tip of the second boom 2 and the second boom 2, and when the third boom 3 contracts, the fourth boom 4 contracts.

Means and Actions for Solving the Problems A second boom is telescopically inserted into the first boom, and a cylinder for extending and retracting the second boom is attached between the first boom and the second boom. A third in the second boom
Of the boom is telescopically inserted, the sheave 32 is attached to the base end of the second boom, and both ends of the reduction rope 31 wound around the sheave 32 are attached to the tip of the first boom and the third boom. A screw rod 35 having a holding yoke 34 on the outer surface of the first boom is movable in the boom extension / contraction direction by connecting to the base end of the boom so that the third boom shrinks together with the second boom. The holding yoke 34 is movable in the boom extension / contraction direction by screwing an adjusting nut 38 onto the threaded rod 35, and the equalizer sheave 30 is attached to the holding yoke 34, and the extension wound around the equalizer sheave 30 is performed. Both ends of the rope for use 28 are connected to the base end of the third boom via the sheave 29 attached to the tip of the second boom so that the third boom moves to the second end.
Boom telescopic device that is designed to extend with the boom.

Accordingly, when the second boom is expanded and contracted with respect to the first boom by expanding and contracting the cylinder, the third boom is expanded and contracted simultaneously by the extension rope 28 and the contraction rope 31, and the third boom is extended. Since both ends of the extension rope 28 to be connected are connected to the base end of the third boom, and the equalizer sheave 30 around which the extension rope 28 is wound is provided on the outer surface of the first boom, the third boom is equalized. The boom is not limited to the size of the sheave 30, and the entire boom can be made small, and the work of winding the extension rope 28 can be easily performed. Moreover, the holding yoke 34 to which the equalizer sheave 30 is attached is located outside the first boom. Since it is provided so that it can be moved and adjusted in the boom extension and contraction direction with the screw rod 35 and the adjustment nut 38 on the side
You can adjust the tension of the extension rope 28 by moving the equalizer sheave 30 in the boom extension and contraction direction by tightening and loosening, and easily perform the tension adjustment work due to the extension strain of the extension rope 28 itself from the outside of the boom. You can

In the first boom 20, the second, third, fourth and fifth booms 21,22,
23 and 24 are telescopically and sequentially inserted, and the first and second booms 20,
The first cylinder 25 is connected between the two, the second cylinder 26 is connected between the second and third booms 21 and 22, and the third cylinder 27 is connected between the third and fourth booms 22 and 23. Both ends of are connected to the rear end of the fifth boom 24, and are wound around a semicircular equalizer sheave 30 provided at the tip of the third boom 22 via a pair of sheaves 29, 29 provided at the tip of the fourth boom 23. Both ends of the pair of left and right reducing ropes 31 have a fifth boom.
It is connected to the base end of 24 and through a pair of sheaves 32, 32 provided at the rear end of the fourth boom 23, and is connected to a holder 33 provided at the tip of the third boom 22.

The equalizer sheave 30 is supported by a holding yoke 34, and a screw rod 35 thereof is screwed into a plate 37 fixed between a pair of brackets 36 fixed to both end walls of the third boom 22 to adjust the nut 3.
8 is screwed together, and the position of the equalizer sheave 30 can be adjusted by moving the holding yoke 34 by loosening and tightening the adjusting nut 38.

Then, when the third cylinder 27 is extended and contracted to extend and retract the fourth boom 23, the extension rope 28 and the reduction rope 31 cause the fifth boom 24 to extend and retract.

Effect of the Invention When the second boom is expanded and contracted with respect to the first boom by expanding and contracting the cylinder, the third boom is expanded and contracted simultaneously by the extension rope 28 and the reduction rope 31.

Since both ends of the extension rope 28 for extending the third boom are connected to the base end of the third boom, and the equalizer sheave 30 around which the extension rope 28 is wound is provided on the outer surface of the first boom, The third boom can be made smaller without being limited to the size of the equalizer sheave 30, and the entire boom can be made compact, and the work of wrapping the extension rope 28 also becomes easy.

The holding yoke 34 to which the equalizer sheave 30 is attached is provided on the outer surface of the first boom so as to be movable and adjustable in the boom extension / contraction direction by the screw rod 35 and the adjusting nut 38.
You can adjust the tension of the extension rope 28 by moving the equalizer sheave 30 in the boom extension and contraction direction by tightening and loosening, and easily perform the tension adjustment work due to the extension strain of the extension rope 28 itself from the outside of the boom. You can

[Brief description of drawings]

1 and 2 are front sectional views, plan views, and FIGS. 3 and 4 are front sectional views and plan views of a conventional example showing an embodiment of the present invention. 28 is an extension rope, 29 is a sheave, and 30 is an equalizer sheave.

Claims (1)

[Scope of utility model registration request] 1. A second boom is telescopically inserted into the first boom, and a cylinder for extending and contracting the second boom is attached between the first boom and the second boom, and the second boom is attached. A third boom is telescopically inserted into the boom, a sheave 32 is attached to the base end of the second boom, and both ends of a reduction rope 31 wound around the sheave 32 are attached to the first boom. A screw rod 35 having a holding yoke 34 is provided on the outer side surface of the first boom so that the third boom is reduced together with the second boom by connecting to the tip end and the base end of the third boom. It is movably supported in the boom extension and contraction direction and its screw rod is attached.
Adjusting nut 38 is screwed to 35 to make it possible to move and adjust holding yoke 34 in the boom extension and contraction direction, attach equalizer sheave 30 to the holding yoke 34, and attach both ends of extension rope 28 wrapped around equalizer sheave 30. A boom telescopic device characterized in that the third boom is extended together with the second boom by being connected to the base end of the third boom via a sheave 29 attached to the tip end of the second boom. .