JP2796516B2 - Structure of backstop in jib crane - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a back stop in a jib crane.

[0002]

2. Description of the Related Art A description will be given with reference to FIGS. In FIG. 1, reference numeral 1 denotes a jib, and a diblore-2 is connected to the tip.
Reference numeral 3 denotes an elevating rope, which is a sheave 5 provided at the end of the rear post 4.
It is wound around. Pendant trophy on rear post 4
6 is attached. The rear post 4 is connected to diblower-2 via a link 7 and a rope 8. The elevating rope 3 is wound up, the rear post 4 is raised, and the pendant loop 6 is connected to the bridle 9. When the rear post 4 is raised, the Ziblower-2 is also raised in conjunction therewith.

[0003] As shown in FIG.
0, a round bar 11, which is fitted in the pipe 10, and whose lower end is pivotally attached to the jib blower-2, a bracket 12 fixed to an intermediate portion of the round bar 11, and a spring 13. The round bar 11 slides in the pipe 10 in the axial direction. The spring 13 is attached to a flange 10a of the pipe 10 at one end and between brackets 12 fixed to the round bar 11 at the other end, and is maintained at a fixed length. The pipe 10 is supported by the jib tip via a hammer 14 and a target 15 whose lower end is pivotally connected to the tip of the jib tip 16.

[0004] With the raising of the jib blower-2, the end of the round bar 11 is slidable in the axial direction of the pipe 10, and the bracket 12 fixed to the round bar 11 and the pipe 10
The spring 13 held between the side flange portions 10a is compressed (FIG. 2). With such a configuration, the elevating rope 3
Is excessively wound, the rear post 4 and the jib blower-2 interlocked with the rear post 4 are excessively raised, and the spring 13 is closely attached to generate a large repulsive force. When the spring 13 comes into close contact, a maximum winding force is generated on the elevating rope 3, which is transmitted from the hammer 14 to the jib tip 16 via the target 15. As a result, there is a problem that the jib tip 16 is damaged.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a backstop which can prevent the jib tip 16 from being damaged even when the rear post 4 is raised too much.

[0006]

In a jib crane,
A round bar 11 mounted on the jib blower-2 side is connected to a pipe 10 slidably fitted in the axial direction of the round bar 11 via a spring 13 and the pipe 10 is further connected to a hammer 14 and a hammer 14. In a backstop device connected to the jib tip 16 via a target 15 which comes into contact with the spring, the spring 13 has one end slidable with respect to the round bar 11 in the form of a press.
The plate 17 was fixed to the tube side of a cylinder 18 having a rod end fixed to the diblower-2 side.

[0007]

When the rod of the cylinder 18 is contracted, the plate 1
The spring 13 has a free length because the guide 7 is guided by the round bar 11 and moves toward the jib blower. For this reason, the spring 13 has a sufficient margin, so that the spring 13 does not adhere to the jib tip 16 even if the jib blower is excessively raised.
Will not be damaged.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. As in the conventional example, the pipe 10 is connected to the hammer 14 by the pin 10b, and
1 has one end connected to Diblor-2. Also round bar 11
Are slidably inserted in the pipe 10. Spring 1
3 is held between the flange portion 10a of the pipe 10 and the plate 17. The plate 17 is fixed to a flange 18a of a cylinder 18 and has a guide hole 17a for the round bar 11. The rod side of the cylinder 18 is connected to the jib blower-2 by a pin 11a. When the cylinder 18 expands and contracts, the plate 17 moves and the spring 13 expands and contracts because the rod end is fixed to the pin 11a.

With the above construction, when the rod of the cylinder 18 is most contracted (shortened), the plate 17 is guided by the round bar 11 and slides toward the pin 11a, and the spring 13 is released to a free length. Is done. And in this state, elevating rope 3
If the elevating rope 3 (FIG. 1) is overwound and the rear post 4 and the lower jib 2 are pulled up too much, the spring 1
3 has a sufficient length because of its free length, so that the spring 13 does not adhere.

[0010]

An end of the spring 13 is supported by a plate 17 slidable with respect to the round bar 11, and the plate 17 is fixed to a cylinder 18 having a rod end fixed to the diblower-2 side. With this configuration, the spring can be released to its free length even if the rear post 4 is raised too much.
Can be prevented from being damaged.

[Brief description of the drawings]

FIG. 1 is a side view of a jib crane having a conventional backstop.

2A is an enlarged view of a backstop mechanism, and FIG. 2B is a detailed sectional view of a spring portion.

3A is a side view of the backstop mechanism of the present invention, and FIG. 3B is a view taken in the direction of arrow B in FIG. 3A.

[Explanation of symbols]

Reference Signs List 1 jib 2 jiblower 3 elevating rope 4 rear post 5 sheave 6 pendant
P 7 Link 8 Rope 9 Bridle 10 Pipe 10a Flange 10b Pin 11 Round bar 11a Pin 12 Bracket 13 Spring 14 Hammer 15 Target 16 Jib tip 17 Plate 17a Guide hole 18 Flange 18a Flange

Claims (1)

(57) [Claims] 1. The method of claim 1, wherein the dibbleene comprises diblower (2).
A round bar (11) attached to the side, and this round bar (11) is connected via a spring (13) to a pipe (10) that is slidably fitted in its axial direction, and this pipe (10) is further connected. The jib tip is connected to the hammer (14) and the target (15) comes into contact with the hammer (14).
(16) In the backstop device connected to the side,
(13) is a plate (1) whose one end is slidable with respect to the round bar (11).
7), wherein the plate (17) is fixed to the tube side of a cylinder (18) having a rod end fixed to the diblower (2) side. Construction.