JPS5837240B2 - lift device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a lifting device used for high-place work by moving a lifting platform up and down.

Lifting devices in which a lifting platform on which workers and materials are placed are moved up and down by hydraulic pressure, etc. have been used for work, repair, painting, etc. at high places.

Most of the lifting devices that have been used in the past have adopted a pantograph type lifting mechanism, in which links are opened and closed by hydraulic cylinders.

In this elevating mechanism, the height at which the pantograph can be raised and lowered is determined by the length of the links that make up the pantograph.

Therefore, in order to extend the height, the length of the link must be increased, which results in bulk when the elevating mechanism is retracted.

In order to improve this drawback, a pair of outer cylinders are rotatably connected at the center to form an X-shape, and inner cylinders are telescopically inserted into both ends of each outer cylinder. A lifting mechanism was also devised to move the platform up and down.

However, when the pair of outer cylinders are in a straight line,
This had the disadvantage that it was impossible to divide the force of the inner cylinder's expansion into a lifting force, making it impossible to operate reliably.

'In view of the above-mentioned drawbacks, the present invention provides an elevating device that can apply an initial stress to the outer cylinder to slightly lift it and reliably convert the stretching force of the inner cylinder into the lifting force of the lifting platform.

An embodiment of the present invention will be described below with reference to the drawings.

Reference numeral 1 denotes a vehicle body, and wheels 2 are pivotally supported at the front and rear of the four corners of the vehicle body 1, and fixing legs 3 that move up and down are fixed at the same time.

An elevating mechanism 4 is connected with a pin on the vehicle body 1, and an elevating platform 5 on which a worker rides is connected with an upper part of the elevating mechanism 4.

A handrail 6 is provided around the upper surface of the elevator platform 5.

The elevating mechanism 4 is composed of an X-shaped row of cylinders 7 that is pivoted at the center, and an inner cylinder 8 that is telescopically inserted into each end of the outer cylinder 7. piled up,
The tip of each inner cylinder 8 is rotatably connected to the upper and lower inner cylinders 8 by a pin 9.

The tip of the lowest inner tube 8 is connected to a shaft support plate 10 fixed to the vehicle body 1 with a pin 11, and the tip of the highest inner tube 8 is connected to a workbench 5 with a pin 12.

In this way, the outer cylinder 7, the inner cylinder 8 and the pins 9, 11, 12
The pantograph is shaped like this.

The same number of combinations of outer cylinders T and inner cylinders 8 are provided on both sides of the vehicle body 1, and a drive mechanism 13 is fixed to the center of each outer cylinder 7.

Next, the structure inside the outer cylinder T will be explained with reference to FIGS. 2 and 3.

A drive shaft 14 is inserted through the center of the outer cylinder γ assembled in an X shape, and the drive shaft 14 and the outer cylinder 7 are pivotally supported by a bearing 15. 7 drive shaft 1
4 is rotatable.

A bevel gear 16 is fixed in each outer cylinder 7 of the drive shaft 14, and a driving shaft 1 of a hydraulic motor 17 is attached to the drive shaft 14.
8 are connected via a clutch 19.

This driving shaft 18 has a semicircular arm 20 as an eccentric body.
is fixed.

A pair of bearing bodies 21 are fixedly attached to positions close to the drive shaft 14 within the outer cylinder 7, and each bearing body 21 is provided with a thrust bearing 22.

A bevel gear 23 that engages with the bevel gear 16 is rotatably supported on each thrust bearing 22.

A threaded rod 24 located at the center of the outer cylinder 7 is connected to the bevel gear 23.

A female screw body 25 is fixed to the end face of the inner tube 8 located inside the outer tube 7, and is screwed into the screw rod 24 into the screw body 25.

Next, the operation of this embodiment will be explained.

The position indicated by the solid line in FIG. 1 is the lowest position of the lifting platform 5, and the inner tube 8 is inserted into the outer tube 7, and the outer tubes 7 are stacked one above the other.

In order to raise the lifting platform 5, first the hydraulic motor 17 is operated to rotate the driving shaft 18 and the arm 20.

When the arm 20 rotates, the arm 20 gradually approaches the vehicle body 1 and comes into contact with the vehicle body 1, thereby lifting the outer cylinder 7.

When the tip of the arm 20 contacts the vehicle body 1, the outer cylinder 7 is tilted by an angle α from the horizontal position.

(See Figure 4) At this time, the clutch 19 engages, and the driving shaft 1
8 and the drive shaft 14 are directly connected, and the drive shaft 14 and the bevel gear 1
6 rotates.

The bevel gear 2 is engaged by the rotation of the bevel gear 16.
3, and the threaded rod 24 rotate.

For this reason, the threaded body 25 is screwed into the threaded rod 24 and moves in the direction of being pushed out from the outer cylinder 7, and the inner cylinder 8 moves into the outer cylinder 7.
The pins 9 are pushed out further and the length between the pins 9 becomes longer.

At the same time, the distance between the pins 9, 11, 12 and the drive shaft 14 becomes longer, the outer tube 7 and the inner tube 8 extend upward in a pantograph shape, and the lifting platform 5 rises.

On the other hand, in order to lower the elevator platform 5, the hydraulic motor 17 may be rotated in the opposite direction.

In this embodiment, the half-moon-shaped arm 20 is used as the eccentric body for lifting the outer cylinder 7, but an eccentric cam or the like may also be used.

Since the present invention is constructed as described above, in order to lift the platform when the outer cylinder and the inner cylinder are in a straight line, it is possible to lift the outer cylinder a little before operating the inner cylinder.
It is possible to reliably raise the elevating platform using the inner cylinder.

Furthermore, when the elevating mechanism is retracted, the pair of outer cylinders can be folded into a straight line 1, and the height when retracted can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a side view showing an embodiment of the present invention, Fig. 2 is a partially sectional side view showing the vicinity of the outer cylinder as above, Fig. 3 is a sectional view of the outer cylinder as above, and Fig. 4 is as above. It is an explanatory diagram showing operation of. 1... Vehicle body, 5... Lifting platform, 7... Outer cylinder, 8...
- Inner cylinder, 14... Drive shaft, 20... Arm as an eccentric body.

Claims (1)

[Claims] 1 A pair of links are rotatably connected at the center to form an X-shape, and each link is configured to be expandable and retractable, and one end of the link is connected to the base with a pin, and the other end can be moved up and down. It is characterized in that it is connected to the base with a pin, a drive shaft is pivotally supported at the center of rotation of the link, and an eccentric body is fixed to the drive shaft that contacts the base side and lifts the center of rotation of the link upward. lift device.