JPH05186187A - Swing lever type tower crane - Google Patents

Abstract

PURPOSE:To provide a swing lever type tower crane by which assembling work or the like can safely be done without causing inconvenience even if a jib is extended from a tower boom and laid along the ground and to which a jig longer than a tower boom can be mounted. CONSTITUTION:A first lever 18 is mounted in the rear of the apex portion of a tower boom 3 in such a manner that it can be rocked and a second lever 19 is fixed via a stay 20 to the back portion of the root of a jib 4. On end portion of a connecting lever 21 is connected to the tip portion of the first lever 18 in such a manner that they are rotatable relative to each other and the other end portion of the connecting lever 21 is connected to the tip portion of the second lever 19 in such a manner that they are rotatable relative to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swing lever type tower crane in which a jib connected to the top of a tower boom is raised by a swing lever.

[0002]

2. Description of the Related Art An example of a conventional tower crane having a swing lever will be described with reference to FIGS.

A revolving structure 2 is rotatably mounted on the upper part of the traveling structure 1, and a tower boom 3 is attached to the front part of the revolving structure 2 so as to be able to rise and fall. Tower boom 3
The jib 4 is connected to the front part of the top part of the device by a pin so that the jib 4 can be raised, and the swing lever 5 having a triangular side surface is swingably mounted to the rear part. The swing lever 5 is composed of three members 5A, 5B and 5C whose ends are connected to each other. The tower boom 3 is held almost vertically during the cargo handling work as shown in FIG.

A yair rope 7 wound out from an undulating drum 6 installed on the revolving structure 2 is stretched over a plurality of sheaves of a jib hanger 8 and a jib bridle 9. The other end of the guy line 10 having one end connected to the jib bridle 9 is joined to the tip of the rear member 5A of the swing lever 5, and the other end of the guy line 11 having one end joined to the tip of the jib 4 has the other end of the swing lever 5. It is connected to the front end of the front member 5C. A guide roller 12 that guides the guy line 10 when the jib 4 is elevated is installed on the rear portion of the tower boom 3 near the top.

The wire rope 14 unwound from the hoisting drum 13 installed on the revolving structure 2 is guided by the sheaves attached to the top of the tower boom 3 and the tip of the jib 4, and the tower boom 3 and the jib 4 are guided. Is passed around the sheave of the hook 15 through the back side of the, and its end is connected to the tip of the jib 4.

The tower boom 3 is supported by a guy line 16 having one end connected to the top and the other end connected to the rear of the revolving unit 2. In the middle back of the tower boom 3,
The upper end of the back stop 17 that prevents the tower boom 3 from falling backward is connected.

FIG. 4 shows a state during the cargo handling work, in which the jib 4 is raised and lowered by swinging the swing lever 5 as the wire rope 7 is wound and unwound.
As the wire rope 14 is wound up and rolled out,
The hook 15 is moved up and down.

[0008]

In such a tower crane, when the jib 4 is extended along the ground G as shown in FIG. The position is not stable because it is only connected to, and problems such as hitting or rubbing the back surface of the jib 4 may occur in some cases. Due to this defect, the jib 4 longer than the tower boom 3 cannot be mounted because the posture shown in FIG. 5 cannot be taken, and the length of the jib is limited. Further, at the time of assembly, as shown in FIG. 6, the jib 4 is held in the tower boom 3, and the joint between the members 5B and 5C of the swing lever 5 and the tip of the jib 4 are brought into contact with the ground G. The top of the tower boom 3 is lifted by the swing lever 5, and the assembling work is performed at a high place.

The present invention has been made in consideration of these, and even when the jib is extended from the tower boom and brought along the ground, no trouble occurs, and safe assembly work can be performed, and An object of the present invention is to provide a swing lever type tower crane capable of mounting a jib longer than a tower boom.

[0010]

According to the swing lever type tower crane of the present invention, the first lever is swingably attached to the rear side of the top of the tower boom, and the second lever is attached to the back side of the root side of the jib. And connect one end of the connecting lever to the tip of the first lever so that it can rotate relative to the other, and rotate the other end of the connecting lever relative to the tip of the second lever. It is characterized in that a swing lever is configured by being connected as much as possible.

[0011]

The link structure of the swing lever is fixed even when the jib is extended in the lengthwise direction of the tower boom and laid down in a posture that follows the ground.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
Will be described. In these figures, FIGS.
The same parts as those shown in FIG.

A first lever 18 is mounted by a pin on the rear side of the top of the tower boom 3 so as to be swingable, and a second lever 19 is mounted on the back side of the base of the jib 4. The second lever 19 is fixed to the jib 4 via a stay 20. That is, one end of the stay 20 is connected to the intermediate portion of the second lever 19, and the other end is connected to the jib 4
It is connected to the middle part near the root of. First lever 18
One end of the connecting lever 21 is connected to the tip of the second lever 19 by a pin so as to be relatively rotatable.
The other end of the connecting lever 21 is connected to the tip of the pin by a pin so that the other end of the connecting lever 21 can relatively rotate. That is, the first lever 18, the second lever 19, the connection lever 21, and the stay 20 constitute a swing lever. One end of the guy line 10 is connected to a connecting portion between the first lever 18 and the connecting lever 21, and one end of the guy line 11 is connected to a connecting portion between the second lever 19 and the connecting lever 21.

FIG. 1 shows a state corresponding to that shown in FIG. 4 during a cargo handling operation, in which the jib 4 is raised at a desired angle.

FIG. 2 shows a state corresponding to FIG. 5 in which the jib 4 is extended from the tower boom 3 and is attached to the ground G. The guide roller 12 receives the middle of the guy line 10. Even in such a posture, since the swing lever link structure is fixed, it is possible to avoid the problem that the jib 4 is hit or rubbed by the swing lever, and the tower boom 3 A longer jib 4 can also be assembled. Furthermore, the swing lever does not lift the top side of the tower boom 3, which facilitates the assembly work.

FIG. 3 shows a state in which the jib 4 is held in the tower boom 3 from the posture shown in FIG. 1, and the guide line 12 receives the middle of the guy line 10.

[0017]

As described above, according to the present invention, the jib is struck or rubbed by the swing lever even when the jib is extended from the tower boom and is placed on the ground. It is possible to avoid problems, and since the top side of the tower boom cannot be lifted by the swing lever, the position of the base part of the jib can be lowered, and the risk of assembly work at high places can be eliminated. Further, the jib can be held in the tower boom as in the conventional swing lever type tower crane.

[Brief description of drawings]

FIG. 1 is a side view showing a posture during cargo handling work according to an embodiment of the present invention,

FIG. 2 is a side view showing a state in which the jib according to one embodiment of the present invention is extended from the tower boom and is along the ground,

FIG. 3 is a side view showing a state in which the jib according to the embodiment of the present invention is held in the tower boom;

FIG. 4 is a side view showing a posture of a conventional swing lever type tower crane during cargo handling work;

FIG. 5 is a side view showing a state in which a jib in a conventional swing lever type tower crane is extended from a tower boom and is along the ground,

FIG. 6 is a side view showing a state in which a jib of a conventional swing lever type tower crane is held by a tower boom and one apex portion of the swing lever is placed on the ground.

[Explanation of symbols]

 1 traveling body 2 revolving structure 3 tower boom 4 jib 6 undulating drum 7 wire rope 8 jib hanger 9 jib bridle 10 guy line 11 guy line 13 hoisting drum 14 wire rope 16 guy line 18 first lever 19 second lever 20 stay 21 connecting lever

Claims (1)

[Claims] 1. A revolving structure is mounted on a traveling structure, a tower boom is attached to the front part of the revolving structure so that the tower boom can be raised and lowered, and a jib is connected to the front part of the top of the tower boom so that the jib can be lifted.
In a swing-lever tower crane with a swing lever for raising and lowering the jib, attach the first lever so that it can swing on the rear side of the top of the tower boom, and secure the second lever on the back of the root side of the jib with a stay. And one end of the connecting lever is rotatably connected to the tip of the first lever, and the other end of the connecting lever is rotatably connected to the tip of the second lever. A swing lever type tower crane characterized by being configured as a swing lever.