JP3234883B2 - Luffing jib crane boom suspension structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a boom suspension structure for luffing jib crane.

[0002]

2. Description of the Related Art FIG. 5 is an overall view of a conventional luffing jib crane. In FIG. 5, reference numeral 1 denotes a boom, and a boom top 1a.
Is provided with a jib 2. Reference numeral 3 denotes a hoisting rope, and 4 denotes a hook for lifting a load. 5 is a front post, and 6 is a rear post. 7 is the top of jib 2 and front post 5
A jib support pendant 8 is provided between the front post 5 and the rear post 6. 9 is a post support pendant, 10 is a boom support pendant, which is stretched between the boom top 1a and the live mast 11, and is driven by a boom hoist drum (not shown).
The boom is raised and lowered by a boom raising and lowering rope 12 driven through a sheave supported by a gantry 13.
Reference numeral 14 denotes a hook winding rope.

FIG. 6 shows a conventional luffing jib crane.
FIG. This is different from FIG.
This is the one in which a boom top suspension device is added to a. That is, a hoisting rope 15 having another hook 15a for a boom top suspension device is added, and a boom suspension seam is attached to the boom top 1a to guide the rope for driving the same. And a support shaft and a guide sheave 17 thereof. When the boom top 1a, the sheave 16 for the boom suspension device and the support shaft for supporting the same are attached in this manner,
The weight, including the incorporation of the boom top 1a, is greater than in the case without the boom top 1a, the maximum length of the boom 1 is shorter, and the lifting capacity of the jib hook 4 is also affected.

[0004]

Problems to be Solved by the Invention
In general, the tower (tray crane) is usually operated only by hanging the jib. However, an operation that requires boom hanging near the crane body may be required. In this case, as shown in FIG. 6, conventionally, a sheave mechanism has been incorporated in the boom top 1a, but in order to change to the boom top 1a with sheave, the boom 2 and the front post are required. 5, the rear post 6, and the boom pendant 10 had to be removed, which required a great deal of labor and time for the replacement work. When these are incorporated, the frame members and the sheath of the beam top 1a are formed.
The addition of the boom shaft and the like increased the weight, and the length of the boom 1 had to be shortened. However, if there is no boom suspension, the boom can naturally be lengthened and the jib suspension performance is improved. Therefore, the boom top 1a has a simple structure without sheave, and the performance without boom suspension is improved. Securing, boo
It is an object of the present invention to add a function with a sheave mechanism when it is necessary to suspend the boom, thereby enabling the suspension of the boom.

[0005]

SUMMARY OF THE INVENTION In a luffing jib having a boom 1 provided on a crane main body and a jib 2 provided on a boom top 1a, between the boom 1 and the boom top 1a. A detachable extension 18 with a sheave is provided to enable the jib suspension by the jib 2 and the boom suspension by the boom 1.
Is an extension bracket 22 and a sheave 2 for the hoisting rope 19 on one side of the extension bracket 22.
0 and a guide sheave 21 on the opposite side, and at the four corners of the upper and lower surfaces of the extension bracket 22, there are provided a connecting lug 23 which is connected to the boom top 1a and the top of the boom 1.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A description will be given based on FIG. FIG.
As shown in FIG. 1, the present invention is provided with an extension with sheave (joint with boom) 18 between the boom top 1a and the top of the boom 1. As shown in FIGS. 2 to 4, the extension 18 with a sheave has an extension bracket 22 provided with a sheave 20 for a hoisting rope 19 and a guide sheave 21 at both ends, and a boom. A connection lug 23 connected to the top of the base 1 and the lower part of the boom top 1a is fixed to the upper and lower four corners in plan view. 20a is a support shaft of the sheave 20, and 21a is a support shaft of the guide sheave 21. If the extension 18 with a sheave is removed and the boom 1 and the boom top 1a are directly connected, a conventional configuration is obtained.

[0007]

According to the construction of the first aspect, the extension 18 with sheave is attached and detached as required, and if not necessary, it is detached, and the work without hanging the boom is carried out. If this is the case, it is possible to suspend the boom, and both functions can be performed, so that a great amount of labor time required for the re-assembly work can be reduced as compared with the conventional art. Also, by removing the extension 18 with the sheave, the construction of the top of the boom can be simplified and the weight can be reduced, so that the length of the boom can be increased, and as a result, the performance of the jib suspension can be improved. Can be.

[Brief description of the drawings]

FIG. 1 is a roughing jib crane provided with an extension with a sheave.

FIG. 2 is a detailed view of a boom top.

FIG. 3 is a side view of an extension with a sheave.

FIG. 4 is a plan view of the same.

FIG. 5 is an overall side view of a known luffing jib crane.

FIG. 6 is an overall side view of a known luffing jib crane provided with a boom suspension mechanism.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Boom 1a Boom top 2 Jib 3 Hoisting rope (jib hook) 4 Hook 5 Front post 6 Rear post 7 Jib support pendant 8 Jib hoisting loop 9 Post support pendant 10 Boom support pendant 11 Live mast 12 Boom hoisting rope 13 Gantry 14 Hoisting rope (jib hook) 15 Hoisting rope (boom hanging hook) 15a hook 16 Boom hanging seam
17 Guide sheave 18 Extension 19 Hoisting rope 20 Sheave for hoisting rope 20a Support shaft 21 Guide sheave 21a Support shaft 22 Extension bracket 23 Connection lug

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B66C 23/42 B66C 23/64-23/70

Claims (1)

(57) [Claims] A boom (1) provided on a crane body;
In a luffing jib provided with a jib (2) provided on a boom top (1a), a detachable extension with a sheave (18) is provided between the boom (1) and the boom top (1a). The jib suspension by the jib (2) and the boom suspension by the boom (1) are enabled, and the extension with sheave (18) is provided with an extension bracket (22) and the extension. Sheave (20) for hoisting rope (19) on one side of bracket (22)
And a guide sheave (21) on the opposite side, and a boom top at each of the upper and lower corners of the extension bracket (22).
(1a) and a boom suspension structure for a luffing jib crane, comprising a connecting lug (23) coupled to a top of the boom (1).