JP3224927B2 - Extension arm type simple 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 simple extended arm type crane which can easily carry out cargo handling in the vicinity of a column, and more particularly to a simple extended arm type crane which can achieve a large head with a simple structure.

[0002]

2. Description of the Related Art There is known an extension arm type simple crane (for example, Japanese Utility Model Laid-Open No. 5-81184) which can ensure a simple operation and a degree of freedom in handling a load. As shown in the side view of the conventional extension arm type simple crane in FIG. 6, the extension arm type simple crane maintains a constant posture by an upright column 51 and a parallel link 52 having one end fixed to an upper portion of the column 51. A bracket 53 swingable in the vertical direction, and an upright shaft 54 provided on the bracket 53.
And an extension arm 55 that is provided so as to be freely rotatable horizontally through the extension arm 55, and receives a hanging load at a distal end portion 56 of the extension arm 55.

In this extension arm type simple crane, a parallel link 52 is turned in a turning range of a rotatable support column 51, and a hydraulic cylinder 5 provided on the parallel link 52 is provided.
The extension and retraction of 2a enables the lifting and lowering of the luggage suspended on the hook 56a.
The rotation of the bracket 53 and the rotation of the extension arm 55 about the upright shaft 54 of the bracket 53 eliminate the restriction on the lifting position of the luggage, thereby securing the degree of freedom in handling the load. Make it possible.

[0004]

However, the head H of the above-mentioned extension arm type simple crane is restricted by the length of the parallel link and its vertical rotation angle range, and the fixed rope is stretched via a pulley. If a general head expansion method is applied to a swivelable extension arm, there is a possibility that the extension arm will be turned by the load or the rope will come off depending on the turning angle of the extension arm, so this method cannot be applied. For this purpose, a large hydraulic cylinder capable of increasing the size of the parallel link or a large stroke is required, and it is unavoidable to increase the size of the entire structure or increase the production cost.

An object of the present invention is to provide an extension arm type simple crane which enables a large head with a simple configuration while suppressing an increase in the size of the configuration or the production cost.

[0006]

In order to solve the above problems, a parallel link fixed at one end, which is driven to swing vertically, and an upright shaft provided on a bracket held in a fixed posture by the parallel link, An extension arm provided so as to be horizontally rotatable via the upright shaft, and in an extension arm type simple crane receiving a hanging load at the extension arm tip, a pulley is provided at the tip of the extension arm, Through this pulley, a rope for load suspension bound under the fixed portion of the parallel link is stretched, and further ,
It is interposed a guide means for guiding the rope along the upright axis the axis of the front Symbol Burakketto.

[0007]

[Function] Since one end of the rope is bound below the fixed part of the parallel link, when the parallel link of the simple crane swings up and down, the rope is taken in and out through the pulley at the tip of the extension arm. The load suspended by the rope is raised and lowered in the range that includes the vertical stroke of the extension arm and the length of the rope, and the rope is guided by the guide means along the upright axis of the bracket. When the arm is turned to make an angle with the parallel link, the rope is pulled in and out via the pulley at the tip of the extension arm without being affected by the turning angle.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a side view of an extension arm type simple crane according to the present invention.

One end 2a of a parallel link 2 is fixed to the upper part of a rotatably standing column 1 so as to be vertically swingable, and a hydraulic cylinder 2b for driving the parallel link 2 to be rocked is provided at the middle stage of the column 1. It is interposed between the unit 1a.

The other end of the parallel link 2 is provided with a bracket 3 having a fixed posture. The bracket 3 has an upright shaft 4, and an extension arm 5 that can be horizontally swiveled through the upright shaft 4, and a pulley 6 is attached to the tip of the extension arm 5.
Is provided.

A rope 7 bound to the middle portion 1a is stretched through the pulley 6, a hook 7a for suspending a load is attached to the other end of the rope 7, and the rope 7 is attached to the axis of the upright shaft 4 of the bracket 3. A guide means for guiding along is provided.

More specifically, the guide means comprises pulleys 8a and 8b provided at a predetermined distance from the bracket 3 and the extension arm 5, respectively. The two pulleys 8a, 8b are positioned such that the rope 7 guided therebetween coincides with or near the axis of the upright shaft 4.

By this guide means, even when the extension arm 5 is rotated about the upright shaft 4, the rope 7 does not come off the pulleys 8a and 8b, and a moment acts on the extension arm 5. The rope 7 can be guided without performing.

The operation of the extension arm type simple crane having the above configuration will be described below.

FIG. 2 is a side view showing the operation of the extension arm type simple crane.

Parallel link 2 of extension arm type simple crane
Is swung up and down by the expansion and contraction of the hydraulic cylinder 2b in response to a command to raise or lower, the distance between one end of the rope 7 bound to the middle portion 1a below the fixed portion of the parallel link 2 and the pulley 8a Is changed, the rope 7 is put in and out through the pulley 6 at the tip of the extension arm 5, and the load suspended by the rope 7 adds the ascending and descending range of the extension arm 5 and the length of the rope going in and out. It is raised and lowered in the range of a large head H.

Further, since the rope 7 is guided along the axis of the upright shaft 4 of the bracket 3 by the guide means, when the extension arm 5 is turned from the position A to make an angle with the parallel link 2 (position B). Also, the rope 7 is inserted and removed through the pulley 6 at the tip of the extension arm 5 without being affected by the turning angle.

As described above, in a simple extension arm type crane capable of handling a load only by a lifting / lowering command, a simple configuration including a rope and its guide means enables a large parallel link and a large stroke large hydraulic cylinder. Therefore, an extension arm type simple crane capable of simple operation and a large head can be configured while avoiding an increase in the overall configuration and an increase in production cost due to the above. Therefore, when the present invention is applied to an extension arm type simple crane for mounting on a vehicle, it is possible to handle a load with a sufficient head even with the limitation of its constituent dimensions.

FIG. 3 is a side view of a simple extension arm type crane having a vehicle-mounted configuration as another embodiment of the present invention.
The same members as those in the above-described embodiment are denoted by the same reference numerals, and detailed description is omitted.

In this extension arm type simple crane, a pulley 9 is provided at a lower side of the parallel link 2, and a rope 7 is stretched through the pulley 9. The pulley 9 eliminates overhang of the rope below the parallel link 2,
The pocket space of the parallel link can be used efficiently.

Further, a rope guard 10 is provided below the bracket 3 so as to straddle the rope 7. This rope guard 10 protects the rope 7 from being caught between the hanger and a hanger (not shown) as a fixing means provided on the vehicle body side for fixing the parallel link 2. To act.

The bracket 3 has an upright shaft 4 on its side. More specifically, as shown in a partially broken plan view (a) of a main portion of the crane shown in FIG. 4 and a turning state diagram (b) thereof, a rope 7 is stretched on the side of the parallel link 2 in FIG. The extension arm 5 has a turning range of 180 degrees on the same side. In this turning range, as shown in FIG.
It is guided between the parallel link 2 and the extension arm 5 by a guide means composed of two pulleys 8a and 8b.

Further, on the side of the parallel link 2 at the upper end of the bracket 3, there is provided a locking mechanism 11 capable of restraining a pin 11a erected on the extension arm 5. For details,
As shown in the plan view of the main part of the extension arm in the swivel-fixed state shown in FIG. 5, the extension arm 5 is pivoted to the side of the parallel link 2 about the upright shaft 4 and its pin 11a forms a movable claw. 3 is restrained by the locking mechanism 11. The locking mechanism 11 is urged to a restraining position by a spring (not shown), and can be released by rotating.

With the above rope guard and locking mechanism,
The parallel link and the extension arm of the extension arm type simple crane according to the present embodiment can be fixed to the vehicle body by a simple operation. In addition, the simple configuration of pulleys at the parallel link pockets makes it possible to effectively use the narrow bed portion of the truck, thereby making it possible to take advantage of the extension arm type simple crane having a degree of freedom in cargo handling.

[0026]

As described above, a rope fixed at one end is stretched through a pulley at the tip of the extension arm of the extension arm type simple crane, and a guide means for guiding the rope on the axis of the extension arm pivot axis. When the parallel link swings up and down, the rope is pulled in and out through the pulley at the tip of the extension arm, and the load suspended by the rope is The ascending / descending length is increased and lowered in a range of a large head H. At this time, since the rope is guided along the axis of the extension arm pivot axis by the guide means, the extension arm is pivoted to form an angle with the parallel link. Also at this time, the rope is pulled in and out via the pulley at the tip of the extension arm without being affected by the turning angle.

Therefore, the simple structure of the rope and the guide means avoids an increase in the size of the parallel link and an increase in the stroke of the hydraulic cylinder, thereby avoiding an increase in the size of the overall structure and an increase in production costs. Can be configured as a simple extension arm type crane capable of a large head, and when applied to a simple extension arm type crane for mounting on vehicles, sufficient head load can be handled even if the configuration size is limited. Becomes

[Brief description of the drawings]

FIG. 1 is a side view of an extension arm type simple crane according to the present invention.

FIG. 2 is a side view showing the operation of the extension arm type simple crane.

FIG. 3 is a side view of a simple extension arm type crane having a vehicle-mounted configuration as another embodiment of the present invention.

FIG. 4 is a partially cutaway plan view of a main part of the crane (a) and its turning state diagram (b).

FIG. 5 is a plan view of an essential part of the crane when the extension arm is swiveled and fixed.

FIG. 6 is a side view of a conventional extension arm type simple crane.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Prop, 1a ... Middle part, 2 ... Parallel link, 2a ... One end, 2b ... Hydraulic cylinder (drive part), 3 ... Bracket, 4 ... Upright shaft, 5 ... Extension arm, 6 ... Pulley, 7 ...
Rope, 7a ... hook, 8a, 8b ... pulley (guide means).

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B66C 23 / 04,23 / 06

Claims (1)

(57) [Claims] 1. A parallel link fixed at one end, which is driven to swing in the vertical direction, an upright shaft provided on a bracket which is maintained in a constant posture by the parallel link, and is provided so as to be horizontally pivotable via the upright shaft. Extension crane which receives a hanging load at the distal end of the extension arm, a pulley is provided at the distal end of the extension arm, and a fixing portion of the parallel link is fixed via the pulley. Stretch the rope for load suspension tied down,
Furthermore, the rope along the upright axis the axis of the front Symbol Burakketto
Extension arm type simple crane, characterized in that interposed a guide means for guiding.