JPH08245184A - Backstop supporting device of jib crane - Google Patents

Abstract

PURPOSE: To miniaturize a backstop supporting device of a jib crane as well as to stabilize operations at the time of being transferred to a working attitude from the time of assembling this jib crane. CONSTITUTION: A roller arm 34 is pivoted to a nearby position of a target 26 tightly installed in a jib 15, attaching a balance roller 37 to one end of this roller arm 34, and then a balance weight 38 is attached tight to the other end of the roller arm 34. At the time of assembling a jib crane, this balance roller 37 is situated upward the target 26, supporting a backstop 25 from the downside. When the jib crane is transferred to a working attitude and the jib 15 becomes upright, the balance roller 37 escapes to the rear of the target 26, therefore a tip of the backstop 25 canes into contact with a recess 26a of the target 26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jib crane, and more particularly to a backstop supporting device for a jib crane.

[0002]

2. Description of the Related Art A conventional backstop support device for a jib crane will be described with reference to FIGS. Figure 11
Indicates a state in which the tower boom 1 and the jib 2 are tilted substantially horizontally when the jib crane is assembled (or disassembled), and the back stop 4 mounted on the tower head 3 is supported by the lever 5.

The back stop 4 is extendable and retractable,
A spring 6 is interposed in the middle portion thereof to urge it in an extended state, and one end thereof is pivotally attached to the tower head 3 so as to be rotatable. A target 7 is fixed to the jib 2, and the tip of the back stop 4 contacts the target 7 when the tower boom 1 is erected during work as described later.

On the other hand, the lever 5 is pivotally mounted on a bracket 8 fixed to the jib 2, and the tip of the lever 5 is formed into a fork shape so that the back stop 4 can be supported and the lever 5 is supported. A weight 9 is fixed to the other end of the lever 5, so that the lever 5 can swing in the front-back direction of the jib 2 (left-right direction in the figure), and when the lever 5 is in no contact with other objects, the lever 5 is in a vertical posture. Is formed.

FIG. 12 shows a state in which the tower boom 1 and the jib 2 are erected during a jib crane operation. The tip of the back stop 4 supported by the lever 5 abuts on the target 7 and a reaction force of the jib 2 to the rear side. Is taking.

[0006]

As described above, the back stop 4 of the conventional jib crane is supported by the lever 5 at the time of assembly and abuts on the target 7 at the time of work.
The lever 5 is large in size to support the weight of the backstop 4, and when the tower boom 1 and the jib 2 are erected, the tip of the lever 5 is placed in the backstop 4.
Since it slides along with, the lever 5 may inadvertently oscillate to cause unstable operation.

Therefore, there is a technical problem to be solved in order to downsize the back stop supporting device of the jib crane and to stabilize the operation at the time of shifting from the assembling to the working posture of the jib crane. The purpose is to solve this problem.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been proposed in order to achieve the above-mentioned object, and a jib is pivotally attached to the tip end portion of the tower boom, and the tower boom is erected at the time of work so that it is attached to the tower head. In a jib crane formed so that the tip of the mounted backstop is supported by a target on the jib side, a hinge pin is provided in the vicinity of the target fixed on the jib in parallel with the pivot pin of the jib, and a roller is attached to this hinge pin. An arm is pivotally attached, a balance roller is attached to one end of the roller arm, and a balance weight is fixed to the other end of the roller arm to make the roller arm swingable, and the roller is irrespective of the jib angle. A backstop support device for the jib crane that is formed so that the ground angle of the arm is constant, and the jib is horizontal when the jib crane is assembled. When the state is close to the state, the balance roller is positioned above the target to support the backstop from below, and when the jib is in an upright state during the jib crane operation, the balance roller escapes to the rear of the target, The backstop support device of the jib crane formed so that the tip of the backstop abuts on the target, and the holding roller is pivotally attached to the lower position of the front post pivotally attached to the rear of the base end of the jib, and the tower is assembled during assembly of the jib crane. When raising the boom, the back stop is supported from below by the holding roller, and when the tip of the back stop comes into contact with the target during jib crane work, the holding roller is separated from the back stop. A backstop support device for a formed jib crane is provided.

[0009]

In the backstop supporting device of the present invention, the roller arm is pivotally mounted at a position near the target, and the ground angle of the roller arm is kept constant by the balance weight. A balance roller is attached to one end of the roller arm, and the balance roller is positioned above the target and supports the back stop from below when the jib is in a substantially horizontal state during assembly of the jib crane.

When the jib is erected during the jib crane operation, the balance roller escapes to the rear of the target, and the tip of the backstop contacts the target to take a reaction force to the rear of the jib.

Further, the holding roller pivotally attached to the lower portion of the front post supports the back stop from below when the tower boom is raised up during assembly of the jib crane. Then, when the jib is raised to bring the jib crane into the working posture, the holding roller separates from the back stop, and the tip of the back stop contacts the target.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIGS. FIG. 1 shows a jib crane 11, in which a tower boom 13 is pivotally attached to a traveling machine body 12, and a jib 15 and a rear post 16 are pivotally attached to a tower head 14 fixed to a tip portion of the tower boom 13. Further, a front post 17 is pivotally attached to the rear of the base end of the jib 15, the front end of the jib 15 and the front end of the front post 17 are connected by a jib support cable 18, and the front end of the front post 17 and the rear post 16 are connected. The jib depression rope 19 is wound around. Further, the rear portion of the tower head 14 and the mast 20.
The tip end of the tower is connected by a tower support cable 21, and the tower elevation rope 24 is wound around the bridle 22 and the bail 23.

In this figure, the solid line indicates the jib crane 1.
1 shows the state at the time of work, and the two-dot chain line is the jib crane 11
The state at the time of assembling (or disassembling) is shown. When assembling on the ground, as shown by the chain double-dashed line, the tower boom 1
3 and the jib 15 are in a substantially horizontal state, the tower boom 24 is hoisted to raise the tower boom 13, and the jib hoist rope 19 is hoisted to raise the jib 15 as shown by the solid line. The tip of the back stop 25 attached to the tower head 14 contacts the target 26 on the jib 15 side to take a reaction force to the rear of the jib 15,
The jib crane 11 is in the working position.

FIG. 2 shows a peripheral portion of the back stop 25 when the jib crane 11 is assembled. For convenience of explanation, FIG.
Illustration of the rear post 16 and various ropes is omitted.
The back stop 25 is extendable and contractible in the same manner as the conventional type, and a spring 27 is interposed in the middle portion thereof to urge it to an extended state, and one end of the back stop 25 is attached to the tower head 1.
It is pivotally attached to 4. Further, a stay 28 is provided so as to protrude from the back stop 25 at a position near the pivot portion, and the tip of the stay 28 is connected by a pin 31 to a long hole 30 of a fixed link 29 pivotally attached to the tower head 14. Therefore, the rotation range of the back stop 25 is restricted within the movement range of the pin 31 in the elongated hole 30.

A hinge pin 33 is provided in the vicinity of the target 26 fixed to the jib 15 in parallel with the pivot pin 32 of the jib. The roller arm 34 is pivotally attached to the hinge pin 33. is there. Figure 3 shows target 2
6 is an enlarged view of the roller arm 34 and the roller arm 34, and the target 26 is fixed to the rear portion of the frame 35 attached to the jib 15. The target 26 is provided with a recess 26a. As will be described later, the tip of the back stop 25 contacts the recess 26a of the target 26 when the jib crane 11 is in operation. In addition, the target 26
A target guide 36 having a fork-shaped tip projects from the lower portion of the back end 25, and the tip of the back stop 25 is locked and guided to the recess 26a of the target 26.

On the other hand, the balance roller 37 is provided at one end of the roller arm 34 pivotally mounted near the target 26.
Is rotatably attached to the roller arm 34.
A balance weight 38 is fixed to the other end of the.
The roller arm 34 is balanced by a balance weight 38, and when the angle of the jib 15 changes, the roller arm 34 swings and the roller arm 34 always has a constant ground angle regardless of the angle of the jib 15. Stop in position.

Therefore, as shown in FIG. 2, when the jib 15 is nearly horizontal when the jib crane 11 is assembled, the balance roller 37 is positioned above the target 26 to support the backstop 25 from below. Interference between the backstop 25 and the target 26 is prevented.

When the tower boom 13 is erected so as to bring the jib crane 11 into a working posture, the backstop 25 comes into contact with the holding roller 39 pivotally attached to the lower position of the front post 17, as shown in FIG. . At this time, the tip of the back stop 25 is the balance roller 3
When the back stop 25 is separated from the balance roller 37, the holding roller 39 supports the back stop 25 from below as shown in FIG.

When the tower boom 13 is further erected, the back stop 25 is once separated from the holding roller 39 and the pin 31 of the stay 28 is raised, as shown in FIG.
Moves to the lower end of the elongated hole 30 of the fixed link 29, and the back stop 25 is supported by the fixed link 29 in a slightly forward tilted posture.

Next, if the jib 15 is raised while keeping the angle of the tower boom 1 as it is, as shown in FIG.
The holding roller 39 again contacts the backstop 25 to support the backstop 25. Jib 1 in such a state
When 5 is further raised, as shown in FIG. 8, the tip of the back stop 25 is locked by the target guide 36 provided on the jib 15 side.

Then, from the state shown in FIG.
5 is erected, the front post 17 is tilted backward, the holding roller 39 is separated from the back stop 25, and the tip of the back stop 25 is scooped up by the target 36 as shown in FIG.
Is guided to the concave portion 26a. As mentioned above, jib 15
Since the roller arm 34 is always balanced so that the ground angle is constant regardless of the angle, the balance roller 37 escapes to the rear of the target 26 and the backstop 25 of the backstop 25 when the jib 15 stands up. It does not interfere with the tip.

Thus, as shown in FIG. 9 and FIG.
The tip of the backstop 25 is the recess 26 of the target 26.
The back stop 25 takes a reaction force to the rear of the jib 15 to bring the jib crane 11 into a working posture.

The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified version.

[0024]

As described in detail in the above one embodiment, the present invention has a roller arm pivotably mounted near a target fixed to a jib so that the roller arm can be swingably attached to one end of the roller arm when the jib crane is assembled. The back stop is supported by the attached balance roller, and the balance roller escapes to the rear of the target during jib crane work, and the tip of the back stop contacts the target.

Since the roller arm is small and lightweight, the operation is stable when the jib crane is moved from the assembling to the working posture, and the backstop is surely supported at the time of assembling and escapes from the target to become the backstop during the working. There is no interference. Therefore, the safety of the work can be secured, and the lifting performance of the jib crane can be improved by reducing the weight.

[Brief description of drawings]

FIG. 1 is a side view of a jib crane showing an embodiment of the present invention.

FIG. 2 is a side view of a main part at the time of assembling the jib crane.

FIG. 3 is an enlarged view of a target and a roller arm.

FIG. 4 is a side view of a main part of a process of shifting the jib crane to a work posture.

FIG. 5 is a side view of essential parts in the process of shifting the jib crane to a work posture.

FIG. 6 is a side view of essential parts in the process of shifting the jib crane to a work posture.

FIG. 7 is a side view of essential parts in the process of shifting the jib crane to a work posture.

FIG. 8 is a side view of a main part of a process of shifting the jib crane to a work posture.

FIG. 9 is an enlarged view of the target and the roller arm in a state where the tip of the backstop is in contact with the target.

FIG. 10 is a side view of a main part when the jib crane is in a work posture.

FIG. 11 is a side view of a main part when a jib crane is assembled, showing a conventional example.

FIG. 12 is a side view of a main part during a jib crane work, showing a conventional example.

[Explanation of symbols]

 11 Jib Crane 13 Tower Boom 14 Tower Head 15 Jib 17 Front Post 25 Back Stop 26 Target 26a Recess 32 Jib Pivot Pin 33 Hinge Pin 34 Roller Arm 37 Balance Roller 38 Balance Weight 39 Holding Roller

Claims (3)

[Claims] 1. A jib is pivotally attached to the tip of the tower boom,
At the time of work, in the jib crane formed so that the tower boom is erected and the tip of the backstop attached to the tower head is supported by the target on the jib side, the jib pivot is located near the target fixed on the jib. A hinge pin is provided in parallel with the landing pin, a roller arm is pivotally attached to this hinge pin, a balance roller is attached to one end of the roller arm, and a balance weight is fixed to the other end of the roller arm to swing the roller arm. A backstop support device for a jib crane, which is movable and is formed such that the ground angle of the roller arm is constant regardless of the angle of the jib. 2. When the jib is close to a horizontal state during assembly of the jib crane, the balance roller is positioned above the target to support the backstop from below, and when the jib is in an upright state during work of the jib crane, 2. The back stop support device for a jib crane according to claim 1, wherein the balance roller is formed so as to escape to the rear of the target and the tip of the back stop contacts the target. 3. A holding roller is pivotally attached to a lower position of a front post pivotally attached to the rear of the base end of the jib, and when the tower boom is raised during assembly of the jib crane, a back stop is provided by the holding roller. The backstop support device for a jib crane according to claim 1 or 2, wherein the backstop support device is formed so that it is supported from below and the holding roller is separated from the backstop when the tip of the backstop comes into contact with the target during jib crane work.