JPH03182497A - Forked jib crane - Google Patents

Abstract

PURPOSE:To expand the application range of the crane work by protruding forked jibs each having a sheave stretched with a wire respectively at the tip section of a boom to allow multi-point hoisting, and freely controlling the attitude and position of a hoisted object. CONSTITUTION:Forked jibs 2 are protruded at the tip section of a boom 1, and sheaves 3 are installed at the tips of the forked jibs 2 so that a wire 4 can be stretched. An object can be hoisted at two points or three points for the so-called multi-point hoisting. The hoisted object can be hoisted and transported in various attitudes and modes by considering the balance with its center of gravity position.

Description

[Detailed Description of the Invention] Industrial Application Field This invention is applicable to lifting of building materials and heavy objects at construction sites, etc.
It relates to jib cranes used for transportation, and more specifically to two-pronged jib cranes that have a three-pronged jib at the tip of the boom.

BACKGROUND OF THE INVENTION Hitherto, various jib cranes have been known and are widely used at many construction sites (FIGS. 5 and 6).

In any case, the boom a has a simple linear box truss structure, and a sheave b is installed at the tip of the boom, and a wire C is stretched over the sheave b to suspend the article d.

Problems to be Solved by the Invention At construction sites, the work involved in lifting and transporting goods using a jib crane is... Jl-sama is diverse. However, Figure 2 A
As shown in , H, the cross-shaped column-beam steel frame 9 is first lifted vertically, then the height of the column steel frame is properly adjusted to a narrow position with vertical restrictions, and the steel frame is transported horizontally in the direction of the arrow. Or, as shown in Figure 3 A and B, the steel frame 10, etc. can be lifted vertically from the lower floors using vertical holes (ducts) in the building, lifted to the top floor 11, and then horizontally lifted. Lifting such as laying it down and laying it horizontally,
Transport operations are simply impossible with conventional jib cranes, and these have become a major problem to be solved.

Means for Solving the Problems As a means for solving the above-mentioned conventional problems, a two-pronged jib crane according to the present invention, as shown in FIGS. 1 to 4 of the drawings, has a boom. A two-pronged jib 2.2 is protruded from the tip of the l, and a sheave 3 is attached to the tip of each two-pronged jib 2.2.
is installed, and the wire 4 is stretched so that the articles 9 and 10 can be positively loaded.

Function: By suspending the article with two wires 4.4 stretched over the sheave 3.3 of the two-pronged jib 2.2, two-point suspension is possible (see Figure 4B). When used in conjunction with the wire 6 stretched over the wire 5, the article can be suspended from three points, making it easy to control the posture of the suspended article (see Figure 3B).
.

Also, the wire 4.4 of the sheave 3.3 of the two-pronged jib 2.2
An article suspended at two points, for example, a column-beam steel frame 9 in the form of a parallel cross, can be suspended at two points by hoisting the upper end of the column with the two-pronged jib 2.
．． It can be supported and transported in a higher position than position 2 (Figure 2B).

a real example The illustrated invention will now be described in detail.

The two-pronged jib crane shown in Figures 1A and B has a two-pronged jib 2.2 protruding from the tip of the basic boom l in a two-pronged arrangement centered on 11F. ing. If you look at the two-pronged jib 2.2 from above, the boom l
The sheaves 3 and 5 are arranged symmetrically with respect to the center, projecting at a slightly downward angle from the boom 1 when viewed from the front, and each sheave 3 and 5 are arranged in substantially the same position.

The two-pronged jib 2.2 does not need to be very long.

Sheaves 5 and 3 are installed at the tip of the boom 1 and the tip of the two-pronged jib 2.2, respectively, and wires 6 and 4 are stretched over them, respectively, so that articles can be lifted. In particular, the wire 4.4 of the two-pronged jib 2.2 is stretched through a tension sheave 8 supported by a stay 7, thereby reducing the lifting moment.

The main usage example of the two-pronged jib crane mentioned above is the 2nd TJ! J and the 31st! Shown in I.

First, in Fig. 2 A, the upper end of the column-shaped beam steel frame 9 is vertically suspended by the wire 6 of the boom l, and the wire 4 of the two-pronged jib 2.2 is properly attached to the beam, but it is loose. The second [! At IB, the wire 4 of the two-pronged jib 2.2, which is fixed at approximately the position of the beam, is wound up, and the top of the column lifts up the lever of the two-pronged jib 2.2, becoming higher than the position of the jib 2. The wire 6 on the boom I side is loose and playing.

In this way, regardless of the height of the two-pronged jib 2, the height position of the suspended column can be adjusted, so even in places where there are obstacles 12 such as slabs above and below, the column-beam steel frame 9 (or The height position of the items (in the pond) can be adjusted appropriately and horizontally transported in the direction of the arrow to perform steel frame erection work (or conversely, demolition work).

Next, in FIG. 3A, the steel frame 10 is lifted up from the lower floor through a vertical hole (duct) of the building in a vertical position by the wire 6 of the boom l. The wire 4 of the two-pronged jib 2 is properly attached to the lower part of the steel frame 10, but it is loose and playing around. FIG. 3B shows that when the steel frame 10 has been hoisted to the top of the building, the wire 4 of the two-pronged jib 2 is hoisted up and the steel frame 1O is laid down in a horizontal position using a jammer. The work condition is shown in which the machine is placed horizontally.

Second Embodiment The two-pronged jib 2 shown in FIGS.
A sheave 3.3 is installed at the tip of the sheave 3.3, and the article 9 or 10 can be lifted by two wires 4.4 stretched on each wire. Therefore, the column and beam steel frame 9 or the steel frame 10 such as H-shaped steel can be suspended at two points using two wires 4.4, and the use and function are the same as those of the first embodiment.

As described in detail in conjunction with the embodiments above and beyond the effects of the present invention, the two-pronged jib crane according to the present invention allows articles to be hung from two or three points, so-called multi-point suspension. It is possible to balance the center of gravity of the object and carry it in various postures and modes, and it is also possible to freely control the posture and position of horizontal objects, so it can be used for lifting and transporting various objects, or for steel frames. It is highly adaptable and flexible for erection work, and greatly contributes to expanding the scope of application of crane work, improving II capabilities, and diversifying it.

[Brief explanation of drawings]

FIGS. 1A and 1B are a plan view and a front view showing the main parts of a two-pronged jib crane according to the present invention, and FIGS. 2A, B, and 3 are
FIA, B is an elevation view that simply shows the application work of a two-pronged jib crane, and Figure 4 A and B are the second elevational views of a two-pronged jib crane.
A perspective view showing an embodiment, and FIGS. 5 and 6 are perspective views showing a conventional general jib crane. l...Boom 2...Two-pronged jib Fig. b Fig. Fig.

Claims (1)

[Scope of Claims] [1] In a jib crane, a two-pronged jib is provided protruding from the tip of the boom, a sheave is installed at the tip of each of the two-pronged jibs, and a wire is stretched across each sheave to lift goods. A two-pronged jib crane characterized by being configured to enable.