JPH0583479B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is useful for lifting workers or materials upward for work such as assembling or painting buildings at high places, or for lifting unnecessary materials at construction sites. This invention relates to a lifting device used for loading and unloading materials.
In particular, regarding a lifting device in which a pair of middle booms are pivoted in an X-shape at the center, and each middle boom has an upper boom and a lower boom inserted therein that extend and contract in the length direction, this middle boom, This invention relates to an elevating device characterized in that a telescoping mechanism consisting of an upper boom and a lower boom is telescopically operated by operating a pair of winding devices provided above the vehicle, and furthermore, the elevating platform can be moved in the horizontal direction. .

[Conventional technology]

Lifting devices that raise and lower platforms are used for assembly, painting, and repairs at high places such as highways and building construction. Workers and materials are placed on the platform and used for lifting and unneeded building materials. I was working on loading and unloading. In this conventional lifting device, a pair of arms are pivoted at the center to make one set, and a pantograph-type extension mechanism is used in which multiple sets of arms are connected vertically (so-called scissor type). In order to increase the maximum lifting height of the lifting device, it was necessary to increase the length of each set of arms or to increase the number of sets of arms to be connected.

For this reason, if we were to design a lifting device that can increase the height that can be climbed, it would be necessary to use multiple sets of pantographs, and the height of the lifting platform with the pantographs folded would be high, making it difficult for workers to climb the platform. The work of getting on and off the vehicle, loading and unloading materials was cumbersome. In addition, because of the cumulative looseness and play in the connecting shafts at each joint of the pantograph, when the platform was raised high, the platform was prone to sway due to wind, etc., causing workers to feel uneasy. .

Various proposals have been made in the past to overcome these drawbacks, such as U.S. Patent No.
A structure as disclosed in the specification of No. 3820631 has also been proposed.

In this proposed structure, a lower boom and an upper boom that can move linearly are inserted into and removed from the middle boom, the lower end of the lower boom is pivotally supported on the vehicle body side with a pin, and the upper end of the upper boom is attached to the platform. It is assembled to form an X-shape by supporting the shaft with a pin. With this structure, the length of the boom itself becomes longer, so the height of the platform can be lowered when it is in the folded state, and the platform can be raised to a higher position.

However, in this invention, the mechanism that extends the lower boom and the upper boom from the middle boom is formed by a screw and a female screw that engages with the screw, so the expansion and contraction speed of the lower boom and upper boom relative to the middle boom is slow, and the platform can be quickly moved. It was impossible to react. In addition, since the lower and middle booms are slid by a screw installed in the center of each middle boom, the total length of the lower and upper booms can be set to only about half the length of the middle boom. The structure was such that the lower boom and upper boom, which can be extended and retracted from the middle boom, could only operate half the length of the middle boom, making it impossible to lift the platform higher.

Also, a structure has been proposed in which another boom is inserted into the boom to increase the length of the telescopic boom itself. For example, in Patent Publication No. 119556 of 1971, in this drawing, in Fig. 4, the lower and upper booms of narrow diameter are inserted into the middle boom of thick diameter, and the lower and upper booms inserted inside are inserted into the middle boom of thick diameter. A structure has been proposed in which the overall length of the boom is increased by sliding it from the boom, thereby raising the platform higher.

However, in this structure, there is no mechanism to synchronize the amount of expansion and contraction between the lower boom and the upper boom, which are pulled out from the middle boom, and the lower boom and upper boom slide independently, and the amount of movement of both is different. is regulated by a bar linkage. For this reason, the platform could not be lifted horizontally in the vertical direction, and could not be lifted horizontally to a desired vertical height position. Also, when the lower boom and upper boom stored inside the middle boom expand and contract,
Since the amount of movement is regulated by the link mechanism formed by the bar, it is impossible to completely synchronize the amounts of movement of both. For this reason, the lower boom is attached to the vehicle body,
The upper boom could not be connected to the platform with pins or the like, and the errors that could not be absorbed had to be made by rollers that were in contact with the car body and the platform. For this reason, the platform has a structure that is prone to shaking due to the accumulation of looseness due to the large number of pivot points in the link mechanism and the rolling motion caused by the rollers, and it is extremely unstable as it easily swings due to wind and other factors. This caused workers to feel uneasy.

In order to eliminate these drawbacks, proposals have been made, such as patent application No. 41289 of 1982 and patent application No. 191065 of 1982. In these applications, a lower boom and an upper boom are inserted into the middle boom, the ends of the lower boom and the upper boom are connected by flexible connecting means, and the connecting means is pivotally supported on the middle boom. It has a structure in which the direction of movement is changed by a conversion means. In this configuration, when the lower boom is pulled out from the middle boom, the boom is pushed out from the middle boom at the same time, and the amount of movement of the lower boom and upper boom is regulated by the linking means, so the amount of movement of the lower boom and the upper boom is regulated by the linking means. are the same, and the pair of middle booms pivoted at the center can rotate in an X-shape to push the platform vertically upward.

In this configuration, the lower and upper booms are housed inside the middle boom, so when the lower and upper booms are extended from the middle boom, their total length is approximately three times that of the middle boom. It can be extended and the platform can be lifted higher than when it is folded.

[Problem that the invention seeks to solve]

However, in these newly proposed lifting devices, in order to operate the lower and upper booms that are pulled out from the two middle booms, a hydraulic cylinder installed in the middle boom must apply operating force in the length direction of the hydraulic cylinder. This operating force must be used to slide the lower boom and the upper boom from the middle boom. This middle stage boom moves upward at the same time as the lifting platform is lifted upward, and the middle boom, which houses this hydraulic cylinder in about half the length of the lifting platform, is lifted.

The hydraulic cylinder itself is quite heavy, and if these hydraulically operated devices are lifted at the same time as the middle boom, the height of the center of gravity will be raised, and as the middle boom is lifted, the center of gravity will also be raised. It had drawbacks.
In addition, since the hydraulic cylinder is housed in the middle boom, a hydraulic cable must be installed between the hydraulic pressure generation source installed on the vehicle body and the middle boom, and the long hydraulic cable is extended to the lower boom and middle boom. This would increase the weight and at the same time make the piping and connection mechanism extremely complicated.

[Means for solving problems]

The present invention consists of a movable vehicle body, a lifting platform located above the vehicle body that can be raised and lowered, a pair of middle booms rotatably supported in the center and combined in an X shape, and a length of each middle boom. A lower boom that slides in the direction and whose lower end is connected to the vehicle body, an upper boom that slides in the length direction of each middle boom and whose upper end is connected to the lifting platform, and each middle boom. In the lifting device, the first winding device is provided on the vehicle body and is rotatably driven in either the forward or reverse direction. a flexible connecting means having one end wrapped around the first winding means and the other end connected to one middle boom via one of the lower booms; This invention provides an elevating device characterized in that it is constituted by a flexible connecting means having one end wrapped around a winding means and the other end connected to the other middle boom via the other lower boom. .

[Effect]

In the present invention, there is a synchronization means between the lower boom and the upper boom, and the lower boom and the upper boom, which are pulled out from the middle boom, are synchronized in their respective expansion and contraction amounts. And on the car body there is a pair of first
and a second winding means, the first,
Flexible linking means wrapped around the second winding means are connected to one middle boom and the other lower boom through one lower boom and the other lower boom, respectively, and are connected to one middle boom and the other lower boom, respectively. By winding up each linking means, the tensile force is transmitted to each middle boom, and each lower boom can be pulled out from each middle boom. Then, the aforementioned synchronizing means act, and each lower boom and each upper boom are pulled out by the same amount of expansion and contraction from each middle boom, and the platform can be lifted to a high position.

Then, when the lifting platform is lifted, if one winding means is stopped and only the other winding means is operated, only one of the connecting means will be wound up, so that one middle stage boom will be lower than the other middle stage. Only the lower and upper booms inserted into the boom can extend and retract. Therefore, the lifted platform can be moved horizontally.

When operating this telescoping function, heavy objects such as hydraulic cylinders are not stored in the middle boom, making the telescoping function extremely light, so the middle boom can be extended and the platform raised high. However, the center of gravity does not shift much, resulting in extremely high stability.

〔Example〕

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

Reference numeral 1 in the figure is a vehicle body equipped with an engine, a hydraulic pressure generating source, etc. Wheels 2 and 3 are pivotally supported on the front, rear, left and right sides of the vehicle body 1, and each wheel 2,
3, crawlers 4 are wound so as to be positioned on both sides of the vehicle body. An elevating mechanism 5 is mounted on the upper surface of the vehicle body 1. A elevating table 6 is fixed to the upper part of the elevating mechanism 5, and a handrail 7 is provided around the elevating table 6.

This lifting mechanism 5 consists of four sets of telescopic booms,
Each set of telescopic boom is composed of a middle boom 10, a lower boom 11, and an upper boom 12. And the middle boom 10,1 made up of two pieces as a set.
0 are rotatably connected at the center by a connecting shaft 13, and two X-shaped middle booms 10 are arranged at both ends of the connecting shaft 13, respectively. A fixed shaft 14 is provided above and below between the middle booms 10 inside each set.
are arranged, and the middle boom 10,
10 is assembled into a ladder shape by a connecting shaft 13 and a fixed shaft 14. The lower boom 11 is connected to the middle boom 10 from the lower end opening of each middle boom 10.
The upper boom 12 is inserted through the upper end opening of each intermediate boom 10 so as to be freely slidable in the length direction. Connecting pieces 15 and 16 are fixed to the ends of the lower boom 11 and the upper boom 12, respectively, and the connecting pieces 15 are rotatably connected to shaft support plates 17 fixed to the front and rear four corners of the vehicle body 1 by pins. There is,
The connecting piece 16 is rotatably connected to a shaft support plate 18 fixed to the front and rear four corners of the lower surface of the lifting platform 6 by a pin.

Further, a kick mechanism 20 is fixed at the center of the vehicle body 1, and the kick mechanism 20 includes a hydraulic cylinder 21 that extends and contracts vertically at the center of the vehicle body 1, and a rod of the hydraulic cylinder 21 that extends horizontally. It is comprised of a push-up bar 22 that contacts the other side of the center of each middle stage boom 10. Further, hydraulic motors 25 and 26 are fixed to the upper surface of the vehicle body 1 at the front and rear portions of the vehicle body 1, respectively, and a winding drum is connected to each of the hydraulic motors 25 and 26 as described later. .

Next, FIGS. 4 and 5 show the internal structure of the above-mentioned telescopic boom, that is, the middle boom 10. The middle boom 10 is made of bent thin steel plate and has a hollow square-shaped cross section. A lower boom 11 is slidably inserted through the lower end of the middle boom 10. The lower boom 11 has an internally hollow rectangular cross section made by bending a thin steel plate, and the upper boom 12 inserted from the other open end of the middle boom 10 is slidably inserted into the lower boom 11. There is. Fan-shaped shaft support pieces 30 and 31 are fixed to both ends of the middle boom 10, respectively, and a pair of guide rollers 32 and 33 are rotatably supported on the shaft support pieces 30 and 31, respectively. The pair of guide rollers 32 are in contact with the upper and lower surfaces of the lower boom 1, and the pair of guide rollers 33 are in contact with the upper and lower surfaces of the upper boom 12, respectively. A bearing plate 34 is fixed to the upper end of the middle boom 10 with a slight release to the side.
Two pulleys 35 and 36 are rotatably supported at a distance from each other. and the upper boom 12
A storage groove 38 is formed in the center of the lower surface, which is slightly inwardly extending to form a space extending in the length direction, and a chain 37 is stored in this storage groove 38. One end of the chain 37 is Storage groove 38
It is fixed to the lower end of the upper boom 12, which is the lower part of the upper boom 12. The chain 37 is connected to the pulleys 35 and 36.
and reverses its direction, chain 3
The other end of 7 is connected to the upper end of lower boom 11 . Next, rollers 39 and 40 are pivotally supported at the upper and lower ends of the lower boom 11, respectively, and a pulley 41 is rotatably supported coaxially with the center of swing of the connecting piece 15 as its axis. be. The wire 42 extends between the lower boom 11 and the upper boom 12 via rollers 40 and 41, and its direction of extension is reversed by the roller 39, and the wire 42 is further extended between the middle boom 10 and the upper boom 1.
2, and its terminal end is connected and fixed to the lower end of the middle boom 10.

FIG. 5 shows a cross section taken along the line A-A in FIG. 4, and a chain 37 and a wire 42 are inserted into a storage groove 38 formed on the lower surface of the upper boom 12 and extending in the length direction. , a wire 42 is also inserted between the middle boom 10 and the lower boom 11.

Next, FIG. 6 shows the vicinity of the lower part of the lower boom 11, and the lower part of each lower boom 11 has the same structure. Here wire 4
2 extends substantially parallel to the surface of the vehicle body 1, and its direction is changed by a pulley 41 supported by a shaft support plate 17, and the lower end opening of the lower boom 11 is connected to a wire 42 by a roller 40 supported by a shaft. is reversed so that its moving direction is directed toward the inside of the lower boom 11. Therefore, by moving the wire 42 back and forth, the direction of action of the pulley 41 and roller 40 is reversed, and the extended wire 42 can move back and forth in the internal space of the middle boom 10 in its length direction.

Further, FIG. 7 shows the vicinity of the hydraulic motors 25 and 26. Each hydraulic motor 25, 26 is operated by hydraulic pressure, and output shafts 45, 47, 48 extend left and right on both sides thereof. A drum 50 is pivotally supported on the output shaft 45, a drum 51 is fixed to the output shaft 46, a drum 52 is fixed to the output shaft 47, and a drum 53 is fixed to the output shaft 48. It has been done.
A wire 42A is wound around the drum 50, a wire 42B is wound around the drum 51, a wire 42C is wound around the drum 52, and a wire 42D is wound around the drum 53. and each wire 42A
-D extend in the direction of each shaft support plate 17 on the vehicle body 1, and each wire 42A-D is inserted into the lower boom 11 from its lower end opening. In other words, the wires 42A to 42D are inserted independently into each of the four lower booms 11, and the two lower booms 1 on the front side of the vehicle body 1.
Wires 42A and 42D that are simultaneously operated by a hydraulic motor 25 are inserted into the two lower booms 11 at the rear of the vehicle body 1, and wires 42C and 4 that are operated by a hydraulic motor 26 are inserted into the two lower booms 11 at the rear of the vehicle body 1.
2D is inserted through each.

Next, FIG. 8 shows the hydraulic system in the lifting device of this embodiment.

The suction side of a hydraulic pump 57 operated by an engine 56 is connected to an oil tank 55 that stores hydraulic oil, and a hydraulic control valve that can be switched to three stages is provided on the projecting side of the hydraulic pump 57. 58, and the discharge side of the hydraulic control valve 58 communicates with the oil tank 55. The hydraulic cylinder 21 is connected to the output side of the hydraulic control valve 58.
and two switching valves 59 and 60, which switch opening and closing in two stages, are respectively connected. The switching valve 59 is connected to the hydraulic motor 25, and the switching valve 60 is connected to the hydraulic motor 26. In other words, if the switching valves 59 and 60 are set to the conducting side, the hydraulic control valve 58
Hydraulic cylinder 21, hydraulic motor 2
5 and 26 can be operated simultaneously. In addition, by setting the switching valves 59 and 60 respectively, either the hydraulic motor 25 or 2
6 can be stopped.

Next, the operation of this embodiment will be explained.

First, the engine 56 installed in the vehicle body 1 is operated, and by operating this engine 56, the hydraulic pump 57 is driven, and the hydraulic oil in the oil tank 55 is sucked by the hydraulic pump 57 to generate hydraulic pressure. Supplied toward the control valve 58.

<When raising and lowering the lifting platform 6> First, when raising and lowering the lifting platform 6 in the vertical direction, the switching valves 59 and 60 are set to the conducting side, and the hydraulic control valve 58 and the hydraulic motors 25 and 26 are set to the conductive side. Keep it conductive. Then, the hydraulic control valve 58 is operated to supply pressure oil from the hydraulic pump 57 in a fixed direction. Then, first the hydraulic cylinder 21
is activated, and the length of the hydraulic cylinder 21 is extended, thereby pushing the push-up bar 22 upward. This push-up bar 22 has four suspended booms 1
The suspension boom 10 comes into contact with the lower surface near the center of each of the suspension booms 10 and has the effect of pushing the suspension boom 10 upward. Therefore, the lower boom 11 and the upper boom 12 are pulled out and lifted from both ends of the suspended boom 10, respectively, and at the same time, the lifting platform 6 is lifted upward.

Therefore, as shown in FIG. 9, the lifting platform 6 is lowered to the lowest position and the middle booms 10 are arranged parallel to each other, and the lower boom 11 and the upper boom are arranged in the interrupted boom 10. 12 is lifted up a little from the stored state, and the middle boom 10 rotates about the connecting shaft 13 so as to form a slightly X-shape. The operation of the hydraulic cylinder 21 causes the middle stage boom 10 to perform an initial lifting operation. Then, since pressure oil is supplied to the hydraulic motors 25 and 26, they operate simultaneously with the operation of the hydraulic cylinder 21, and the output shafts 45, 46, 47, and 48 of each hydraulic motor 25 and 26 rotate in the positive direction, respectively. , a wire 42A which is rotated and wound around each drum 50, 51, 52, 53.
~D are rotated in the respective winding directions. Therefore, the wires 42A to 42D are wound up and act to draw out the wires 42A to 42D from the opening of the lower boom 11, respectively.

Wire 42 pulled out from lower boom 11
The tips of wires A to D span the outer and inner surfaces of the lower boom 11, respectively, and the tips are connected to the lower end of the middle boom 10, so when the wires 42A to D are pulled out, the middle boom 10 is connected to the lower boom 11. It is pulled out as if being pushed upwards. Therefore, the lower boom 11 is lower than the middle boom 10.
However, the lower end of the upper boom 12 is connected to the lower boom 11 by a chain 37, and the pulley 3
5, the chain 37 is moved so that the lower boom 11 is pulled out from the middle boom 10 and the upper boom 12 is also pushed up from the upper end opening of the middle boom 10.
is slid through. Therefore each wire 42
At the same time that A to D are wound up by the drums 50 to 53, the lower boom 11 and the upper boom 12 are slid by the same amount of extension from the upper end of the middle boom 10, and the total length of the telescopic boom body is It gradually becomes longer. Since the lower booms 11 are each supported by a shaft supporting plate 17, the intervals between them are constant, so the middle boom 10 rotates around the connecting shaft 13 in an X-shape to horizontally move the platform. This will have the effect of raising it higher while maintaining it. At this time, the distance from each shaft support plate 17 to the connection shaft 13 and the distance from each shaft support plate 18 to the connection shaft 13 are uniform, and the connection shaft 13 always rises in a direction perpendicular to the vehicle body 1. . Therefore, the lifting platform 6 is always parallel to the vehicle body 1 and is lifted in a direction perpendicular to the vehicle body 1.

FIG. 10 shows that the initial lifting is completed by the kick mechanism 20, and the lower boom 11 and the upper boom 12 are moved to the middle boom 1 by the hydraulic motor 25.
It is pulled out from 0 and shows the state where the elevator platform is raised halfway.

In addition, in FIGS. 2 and 3, the wires 42A to 42D are wound up by the hydraulic motors 25 and 26, and the lifting platform 6
The figure shows the state where it has been raised to its maximum height.

When the lifting platform 6 is lifted to a predetermined position, the hydraulic control valve 58 is closed to stop the hydraulic motors 25 and 26, and the output shafts 45 to 48 are fixed in that state. , the height position of the lifting platform 6 is maintained in that state.

When the elevator platform 6 is to be lowered, the hydraulic control valve 58 is switched in the opposite direction to operate the hydraulic motors 25 and 26 in the opposite direction. Then, the output shafts 45 to 48 rotate in opposite directions, and the wires 42A to 42D wound by the drums 50 to 53 are gradually unwound, and each wire 4
2A to 2D are gradually pushed between each middle boom 10 and lower boom 11. Therefore, the lifting platform 6 acts to insert the wires 42A to 42D into the lower boom 11 by its own weight, and the lower boom 11 and the upper boom 12 slide so as to be inserted into the middle boom 10. Therefore, the length of the telescopic boom body is shortened, the pair of middle booms 10 rotate in opposite directions around the connecting shaft 13, and the lifting platform 6 is lowered to narrow the opening angle. , move closer to the vehicle body 1.
and the wire 42A by the drums 50-53.
~D are all unwound, the lower boom 11 and the upper boom 12 are all stored in the middle boom 10, and the total length of the telescopic boom body becomes the shortest length, returning to the state shown in FIG. 9. The height of the lifting platform 6 will be lowered to the lowest position.

<When moving the lifting platform 6 horizontally> Next, as described above, from the initial lifting operation, the middle boom 10 is rotated in a slightly X-shape, and with the lifting platform 6 raised to a certain height position, To explain the case where the lifting platform 6 is moved in the horizontal direction, first, when the lifting platform 6 is moved to a certain height as shown in FIG.
The switching valve 59 is closed to stop the supply of pressure oil to the hydraulic motor 25. In this state, when the hydraulic control valve 58 is moved in the positive direction, hydraulic pressure is supplied only to the hydraulic motor 26, the hydraulic motor 26 is operated, the output shafts 47 and 48 are rotated, and the drums 52 and 53 are driven. wire 42
C and 42D are respectively wound up. As a result, the wires 42C and 42D in the two middle booms 10 on the right side in FIG.
are respectively slid in the direction A in FIG. 11 from the middle boom 10.

As a result, the distribution of the lengths of the telescopic boom bodies, which used to be equally spaced on the left and right with the connecting shaft 13 as the center, becomes different, so that the connecting shaft 13 can be used to extend the lower boom 11 extending in the direction A. The isosceles triangle formed by the connecting shaft 13 and the pair of support plates 17 collapses, and is transformed into a triangle whose length in the A direction is increased. At the same time, the triangle of the upper boom 12 extending in the A direction is also deformed from an isosceles triangle, and becomes a deformed triangle having the same shape above and below about the connecting shaft 13. Therefore, at the same time that the connecting shaft 13 moves slightly in the horizontal direction, the lifting platform 6 moves in the horizontal direction B by twice the amount of movement, and the tip of the lifting platform 6 moves forward of the tip of the vehicle body 1. It can be moved horizontally. In this way, the elevator platform 6 can be moved close to a wall or the side of a building while the vehicle body 1 remains stationary.

In addition, when moving the elevator platform 6 horizontally to the rear of the vehicle body 1, contrary to the above, the switching valve 60
The switching valve 59 is left open. As a result, pressure oil is supplied from the hydraulic pump 57 only to the hydraulic motor 25 via the hydraulic control valve 58. For this reason, hydraulic motor 2
Drums 50, 5 fixed to output shafts 45, 46 of 5
1 rotates, and the lower boom 11 and the upper boom 12 are each pulled out in the C direction from the middle boom 10 on the left in FIG. 12, and the connecting shaft 13 moves to the right in FIG. It turns out. At the same time, the elevating platform 6 also moves horizontally in the direction D in the figure, and the rear end of the elevating platform 6 is connected to the vehicle body 1.
It can be moved further horizontally than the rear end. Note that at this time, since the amount that the lower boom 11 and the upper boom 12 each moved in the C direction is the same, the triangle formed by the connecting shaft 13 and the supporting plate 17 and the connecting shaft 13 and the supporting plate 18 Since each of the triangles thus formed has a symmetrical shape, the elevator platform 6 can be moved while being maintained horizontally with respect to the vehicle body 1.

〔effect〕

Since the present invention is constructed as described above, in the lifting device that moves the lifting platform up and down by extending and contracting the middle boom, the upper boom, and the lower boom, an extension mechanism consisting of the middle boom, the lower boom, and the upper boom is provided on the vehicle body. By winding up the linking means with a winding mechanism, the expansion and contraction operations can be performed. For this reason, there is no need to provide a hydraulic cylinder or other hydraulic actuating device within the middle boom, so the weight of the entire telescoping mechanism can be reduced. Therefore, even if the elevating mechanism is expanded and contracted to raise the elevating platform to a high level, the center of gravity will not become high, and the elevating platform can be held extremely stably.

In addition, since there is no hydraulic cylinder in the middle boom, there is no need for hydraulic cables or other piping, making the mechanism extremely simple, and all operating mechanisms are fixed on the vehicle body, making assembly and maintenance extremely easy. It is something.

Furthermore, by controlling each of the two hydraulic motors, it is possible to operate only one side of the X-shaped middle boom seen from the side and control only the lower boom and upper boom of that one middle boom. Since the lifting platform can be moved horizontally while being kept horizontal, the lifting platform can be moved horizontally to match the work site, which widens the range of applications.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing a state in which the elevating platform is raised to the maximum position in an elevating device which is an embodiment of the present invention; Fig. 2 is a side view of the same; Fig. 3 is a front view of the same; 4 is a side sectional view showing the internal configuration of the telescopic mechanism, FIG. 5 is a longitudinal sectional view taken along the line A-A in FIG. 4, and FIG. 6 is an enlarged perspective view showing the vicinity of each opening of the lower boom. Figure 7 is a configuration diagram showing the vicinity of the hydraulic motor, Figure 8 is a piping diagram showing the hydraulic system, Figure 9 is a side view showing the lifting platform lowered to its lowest position, and Figure 10 is a diagram showing the lifting platform lowered to its lowest position. Fig. 11 is a side view showing the lifting platform moved horizontally to the front of the vehicle; Fig. 12 is a side view showing the lifting platform moved horizontally to the front of the vehicle. It is a side view which shows the state horizontally moved backward. 1... Vehicle body, 5... Lifting mechanism, 6... Lifting platform,
10...middle boom, 11...lower boom, 12
...Upper boom, 37...Chain, 42...Wire, 25,26...Hydraulic motor, 45,46,
47, 48...Output shaft, 50, 51, 52, 53
……drum.

Claims (1)

[Claims] 1 A movable vehicle body, a lifting platform located above the vehicle body that can be raised and lowered, a pair of middle booms that are rotatably supported in the center and combined in an X shape, and each middle boom has a A lower boom whose lower end is connected to the vehicle body and which slides along the vehicle body, an upper boom whose upper end is connected to the lifting platform and which slides along the length of each intermediate boom, and a lower boom that is installed inside each intermediate boom. and a synchronizing means for synchronizing the travel distances of the lower boom and the upper boom in the middle boom, a first winding means provided on the vehicle body and rotatably driven in either forward or reverse directions; a second winding means; a flexible connecting means having one end wound around the first winding means and the other end connected to one middle boom via one of the lower booms; 1. An elevating device characterized by comprising a flexible connecting means having one end wrapped around the handle means and the other end connected to the other middle boom via the other lower boom.