JP4070749B2 - Horizontal load absorption method and apparatus for lifting jack apparatus - Google Patents

Description

  The present invention relates to a horizontal load absorbing method in a lifting jack apparatus that absorbs a horizontal load due to a lateral load generated in a loading platform in a lifting jack apparatus that lifts and lowers heavy objects, and a device therefor.

In general, as shown in FIG. 4, when a heavy object such as a bridge girder or a bridge is lifted or lowered by a heavy truck of several tens tons or more, or transported to a predetermined position by a carriage, as shown in FIG. Is used (Patent Document 1).
As shown in FIGS. 5 and 6, the lifting jack device 11 is extended and retracted between the four spherical bearings 21 on the upper surface of the base 13 and the four spherical bearings 22 on the lower surface of the loading platform 14. A loading platform lifting cylinder 15 is attached, and a pair of right and left two-folded link mechanisms 16 each consisting of a link bar 16a and a link bar 16b are connected by a cross beam 23 between the base 13 and the loading platform 14, and one end is a pin. The other end of the link cylinder 19 is supported by the base 13 and the loading platform 14 at a fulcrum 18a and a fulcrum 18b, and adjusts the opening degree of the link mechanism 16 between the transverse beam 23 and the base 13. Is provided.
With such a configuration, the loading platform 14 can be moved up and down while keeping the level, and the loading platform lifting cylinders 15 are alternately expanded and contracted while adjusting the opening degree of the link mechanism 16 to tilt the loading platform 14. You can go up and down.

However, since the elevating jack apparatus 11 shown in FIGS. 5 and 6 is connected to the link mechanism 16 and the link cylinder 19 so that they can be bent by a rotating shaft, when a horizontal load is applied to the loading platform 14, The horizontal load cannot be absorbed reliably.
Therefore, as shown in FIGS. 7 to 9, the present applicant has arranged a link mechanism 25 including a pair of telescopic jack devices 24, 24 in an X shape between the base 13 and the loading platform 14. Things are being implemented. The link mechanisms 25 are arranged in two pairs each facing the sides of the longitudinal direction and the lateral direction between the base 13 and the loading platform 14.
By adopting such a configuration, the length of the telescopic jack device 24 is fixed so that it acts as a brace when a horizontal load is applied, and the lifting jack device can absorb the horizontal load that is stopped. it can.
JP 2000-289994 A

7 to 9 can absorb the horizontal load when a horizontal load is applied, but not only the four platform lifting cylinders 15 but also eight link mechanisms 25 are attached. Since it is a structure, it is complicated and expensive.
Further, in the structure in which the eight link mechanisms 25 are attached, the weight as the lifting jack device 11 increases.
Furthermore, since one pair of the X-shaped pair of telescopic jack devices 24, 24 acts as a compressive force and the other acts as a tensile force with respect to a horizontal load in a certain direction, the pump unit is at least 2 The stand is necessary, and its control becomes troublesome.
Furthermore, although the lifting jack device can absorb the horizontal load that is stopped, the horizontal load cannot be reliably absorbed when a horizontal horizontal load is applied during the ascending or descending operation.
There were problems such as.

  An object of the present invention is to provide a horizontal load absorbing device in an elevating jack device that is simple in structure, inexpensive, and simple in pump control.

  The present invention relates to a lifting / lowering jack apparatus that lifts and lowers a loading platform 31 on a base 30 with a lifting / lowering jack 32. The loading platform 31 has two pairs of one end of a wire 34a (+) and a wire 34a (-). A fixed sheave 35 and a movable sheave 36 attached to the base 30 are interposed in the middle of one of the wires 34a (+), and the other end of the wire 34a (+) is attached to the base 30. The direction change sheave 37 that is fixed, crosses in an X shape so as to generate tension in the opposite direction to the wire 34a (+) at the intermediate portion of the wire 34a (−), and is attached to the base 30. A fixed sheave 35 and a movable sheave 36 are interposed, and the other end of the wire 34 a (−) is fixed to the base 30, and between the fixed shaft 43 of the fixed sheave 35 and the movable shaft 42 of the movable sheave 36. , Of the loading platform 31 A horizontal load absorbing device in the lifting jack device being characterized in that connecting the tensioning jack 39 that generates tension for combating flat load.

The invention according to claim 1 is a lifting jack device that lifts and lowers a loading platform on a platform with a lifting jack, and a fixed sheave and a direction change sheave are fixedly attached to either the platform or the loading platform , A movable sheave is movably disposed between the fixed sheave and the direction change sheave, and a tension is provided between the fixed shaft of the fixed sheave and the movable shaft of the movable sheave to face the horizontal load of the loading platform. A tension applying jack to be generated is connected , and two ends of a pair of wires are fixed to the base and the loading platform, respectively, and one side of the pair of wires is attached to the fixed sheave. From the fixed end of the movable sheave and the fixed sheave, the direction is reversed between the fixed sheave and the fixed sheave on the side where the fixed sheave is not attached. X-shaped so as to generate tension in opposite directions by reversing the direction from the fixed end to the fixed end on the side where the fixed sheave is not mounted by reversing the direction with the movable sheave, fixed sheave and direction change sheave. since was allowed intersect, the wire, and the movable sheave, only tensioning jack, the structure is simple, inexpensive, yet can provide a horizontal load absorbing device in a simple lifting jack device of the pump control.
In addition, a pair of wires with two wires fixed at both ends are crossed in an X shape so as to generate tension in opposite directions, and a fixed sheave and a movable sheave are interposed in the middle of one of these wires. However, a direction changing sheave, a fixed sheave, and a movable sheave are interposed in the middle of the other wire, and a tension applying jack that generates tension for facing the horizontal load of the loading platform is connected to the movable sheave. It can prevent against horizontal load in the direction.
Further, two pairs of wires can be applied with different tensions in one direction by a single jack for applying tension, and different tensions can be controlled by one pump device.

  In the invention according to claim 4, since the two pairs of the wires 34a (+) and the wires 34a (-) that generate tension in opposite directions are arranged on both sides of the tension applying jack 39, The tension balance between the wires 34a (+) and 34a (-) on both sides of the tension applying jack 39 is balanced, the structure is simple, and the operation is stable.

  The invention according to claim 5 is the x direction in which two pairs of wires 34a (+) and wires 34a (-), which generate tension in opposite directions, are arranged on both sides of the tension applying jack 39. A horizontal load absorbing device 33a and a y-direction horizontal load absorbing device 33b having the same configuration as the x-direction horizontal load absorbing device 33a are arranged with an angle of about 90 degrees between the base 30 and the loading platform 31. Therefore, the horizontal load direction operates stably not only in the x-axis direction and the y-axis direction but also in horizontal loads in all directions of 360 degrees.

The invention according to claim 6 is a lifting jack device that lifts and lowers a loading platform on a platform with a lifting jack, and a fixed sheave and a direction change sheave are fixedly attached to either the platform or the loading platform , A movable sheave is movably disposed between the fixed sheave and the direction change sheave, and a tension is provided between the fixed shaft of the fixed sheave and the movable shaft of the movable sheave to face the horizontal load of the loading platform. A tension applying jack to be generated is connected, and one end of a pair of wires is fixed to each of the base and the cargo bed, and one side of the pair of wires is attached to the fixed sheave. From the fixed end of the fixed sheave, the direction of the movable sheave and the fixed sheave is reversed, and the direction is spanned to the fixed end on the side where the fixed sheave is not mounted. X-shaped so that tension is generated in the opposite direction by reversing the direction from the fixed end to the fixed sheave on the side where the fixed sheave is not mounted by reversing the direction with the movable sheave, fixed sheave and direction change sheave. When the horizontal load does not act on the cargo bed, the same tension is generated on each of the pair of wires, and the horizontal load acts on the cargo bed. When this occurs, the tension generated in one of the pair of wires is increased against the horizontal load, and the tension generated in the other is decreased by that amount and balanced to a constant value. Since the horizontal load is absorbed while following the lifting operation of the lifting jack, not only when the lifting jack device is in a stationary state, but also the lifting jack device is It can absorb the horizontal load to follow it even during operation at the time of or descending.

  A seventh aspect of the present invention is the same as the sixth aspect of the present invention, in which the same number of two pairs of wires 34a (+) and wires 34a (-) are generated on the both sides of the tension applying jack 39 with two wires generating tension in opposite directions. The x-direction horizontal load absorber 33a and the y-direction horizontal load absorber 33b having the same configuration as the x-direction horizontal load absorber 33a are arranged at an angle of approximately 90 degrees between the base 30 and the platform 31. Since the control is performed so that the tensioning jack output is kept constant by interposing a relief valve between the pump and one pump coupled to the tensioning jack 39, the lifting jack device is raised. Alternatively, it is possible to absorb a horizontal load in any direction of 360 degrees following the movement even when the vehicle is moving down.

  In the present invention, a plurality of lifting jacks 32 are used to lift and lower the loading platform 31, but the one that absorbs the horizontal load is mainly a wire 34 instead of the telescopic jack device 24 composed of a cylinder and a piston rod. And a plurality of fixed sheaves 35, movable sheaves 36, direction changing sheaves 37 and one tension applying jack 39, and one tension applying jack 39 for horizontal loads in different directions in the left and right or front and rear directions. Correspond with. A plurality of sets of these horizontal load absorbing devices 33 are installed between the base 30 and the bed 31. The horizontal load in one direction is absorbed only by the pulling force of one wire 34, and the compressive force does not act on the other wire 34. With such a configuration, a plurality of sets of tension applying jacks 39 can be controlled by a single pump unit.

A horizontal load absorbing method in a lifting jack apparatus according to the present invention and a first embodiment of the apparatus will be described with reference to FIGS.
30 is a base, and 31 is a loading platform. At four corners between the base 30 and the loading platform 31, multistage, for example, four-stage lifting jacks 32 are provided.
Between the base 30 and the loading platform 31, x-direction horizontal load absorbing devices 33a and 33a are provided slightly inside the front and rear sides, respectively, and y-direction horizontal loads are respectively placed slightly inside the left and right sides. Absorbers 33b and 33b are provided.

Since the four x-direction horizontal load absorbers 33a and 33a and the y-direction horizontal load absorbers 33b and 33b have the same basic configuration, one x-direction horizontal load absorber 33a will be described in detail.
A fixed shaft 43 is attached horizontally to the base 30, and one end of a cylinder 40 constituting a tension applying jack 39 is attached to the center of the fixed shaft 43, and two pieces are fixed to both sides of the cylinder 40. A sheave 35 is pivotally attached.
Further, two fixed shafts 44 are attached horizontally to the base 30 at a distance from the fixed shaft 43, and a direction change sheave 37 is attached to each of the fixed shafts 44. A movable shaft 42 is disposed between the fixed shaft 44 and the fixed shaft 43, and one end of a piston rod 41 constituting a tension applying jack 39 is attached to the center of the movable shaft 42, and both sides of the cylinder 40 are attached. , Two movable sheaves 36 are rotatably attached.
Wires 34 a (+) and 34 a (−) are wound around the fixed sheave 35, the movable sheave 36, and the direction change sheave 37.

  More specifically, for example, in FIG. 1, when the horizontal load in the left direction is x (−) and the horizontal load in the right direction is x (+), the wire 34a (−) that opposes the horizontal load x (−) in the left direction. 1), as shown in FIG. 1A, the lower fixed end 38 is positioned between the fixed sheave 35 and the movable sheave 36 and is fixed to the base 30, and the free end is located on the upper side from the lower side of the movable sheave 36. Then, the direction of the fixed sheave 35 is changed from the upper side to the lower side, and then the direction of the direction change sheave 37 is changed from the lower side to the upper side. Is fixed to the loading platform 31 positioned substantially at the upper portion of the fixed sheave 35.

  The wire 34a (+) that opposes the horizontal load x (+) in the right direction is such that the lower fixed end 38 is positioned between the fixed sheave 35 and the movable sheave 36 as shown in FIG. 30, the free end makes a half turn from the upper side to the lower side of the movable sheave 36 and changes its direction by 180 degrees, and then makes a half turn from the lower side to the upper side of the fixed sheave 35 to change its direction by 180 degrees, and the upper fixed end 38 is fixed to the loading platform 31 located substantially above the direction change sheave 37.

In this way, the wire 34a (−) and the wire 34a (+) are arranged in an X shape in order to generate tension in different directions on the left and right by one tension applying jack 39, and one wire 34a ( −) Changes the direction by 180 degrees with an extra direction change sheave 37 than the other wire 34a (+).
In addition, it is attached to one horizontal load absorbing device and is configured to operate in a balanced manner by arranging four wires 34a (-) and one wire 34a (+), one on each side of the tension applying jack 39. is doing. However, it is not limited to this.

The horizontal load absorber 33 configured as described above is provided with two sets of x-direction horizontal load absorbers 33a and 33a slightly inside the front and rear sides between the base 30 and the cargo bed 31, respectively. It counters the horizontal load x (−) and the horizontal load x (+).
Similarly, two sets of y-direction horizontal load absorbing devices 33b and 33b are provided slightly inside the left and right sides between the base 30 and the loading platform 31, and the horizontal load y (−) and the horizontal load y ( It is designed to counter (+).

In the configuration as described above, in the state where the loading platform 31 on which a heavy object is loaded is all elevated by the four lifting jacks 32 as shown in FIGS. Pressure oil is supplied to the cylinder 40 to apply a force in the direction in which the piston rod 41 of the tension applying jack 39 is extended.
Then, as shown by the arrow in FIG. 1 (a), the wire 34a (−) moves the movable sheave 36 to the right in the drawing via the movable shaft 42, and tension is generated in the left direction. A rightward tension is generated in the cargo bed 31 via the fixed sheave 35 and the direction change sheave 37.
Further, as shown by an arrow in FIG. 1 (b), the wire 34a (+) has a movable sheave 36 that moves to the left in the drawing via the movable shaft 42, and tension is generated in the right direction. A leftward tension is generated in the cargo bed 31 via the fixed sheave 35.
Similarly, all the x-direction horizontal load absorbers 33a and 33a slightly inside the front and rear sides between the base 30 and the cargo bed 31 and the left and right sides between the base 30 and the cargo bed 31 A predetermined tension is generated on all the wires 34 with all the y-direction horizontal load absorbing devices 33b and 33b slightly inside the side.

In this state, assuming that a horizontal load is applied to the loading platform 31 in a direction parallel to the x (−) direction in FIG. 1A, the horizontal load x (−) is all supported by the tension of the wire 34a (−). It is done. In the illustrated example, since there are two sets of x-direction horizontal load absorbing devices 33a, they are supported by half. At this time, the tension of the wire 34a (+) becomes zero. That is, in a state where no horizontal load is applied, an equal amount of tension is applied to the wire 34a (−) and the wire 34a (+), but the wire 34a (−) or the wire 34a (+) is parallel to the wire 34a (+). When a load is applied, the horizontal load is supported only by the tension of either the wire 34a (−) or the wire 34a (+). At this time, the wire 34b (−) or the wire 34b (+) is orthogonal to the direction of the horizontal load and thus does not support the horizontal load.
Similarly, when a horizontal load is applied in a direction parallel to the wire 34b (−) or the wire 34b (+), the horizontal load is supported only by the tension of either the wire 34b (−) or the wire 34b (+). At this time, since the wire 34a (−) or the wire 34a (+) is orthogonal to the direction of the horizontal load, it does not support the horizontal load.

  Next, assuming that the direction of the horizontal load T is oblique by θ degrees with respect to the x-axis, the vector in the x-axis direction is T · cos θ and the vector in the y-axis direction is T · sin θ. The horizontal load of T · cos θ is supported by the tension of either (−) or the wire 34a (+), and the horizontal load of T · sin θ is supported by the tension of either the wire 34b (−) or the wire 34b (+). Support the load. In the illustrated example, since there are two sets of the x-direction horizontal load absorbing device 33a and the y-direction horizontal load absorbing device 33b, each of them is supported by half.

The above operation is mainly an explanation of the operation when the lifting / lowering jack device is stationary. However, even when the lifting / lowering jack device is moving up or down, it follows and absorbs horizontal loads in all directions of 360 degrees. This is a very important feature of the present invention.
The reason will be described below.

  Next, as shown in FIGS. 2 (a) and 2 (b), when all the four lifting jacks 32 are lowered and the loading platform 31 is directly placed on the base 30, all the wires 34 are loosened. Accordingly, pressure oil is supplied to the cylinder 40 in accordance with the lowering of the raising / lowering jack 32 to extend the piston rod 41 of the tension applying jack 39 and apply a predetermined tension to all the wires 34.

In FIG. 3, the tension T of the wire 34 a (−) is mediated by the direction change sheave 37, the fixed sheave 35, and the movable sheave 36, and the tension T of the wire 34 a (+) is applied to the fixed sheave 35 and the movable sheave 36. Each acts as an axial force P on the tension applying jack 39.
Assuming that the axial force P during the horizontal action is the maximum tension Tmax = 180 kN,
P = 2Tmax = 2 × 180 = 360 kN
Thus, the ability of the tension applying jack 39 is 360 kN.

  The control of the raising / lowering jack 32 is synchronized by configuring the jack and the pump one-to-one at the time of jack-up. However, in order to cope with variation due to a reaction force difference (pressure difference), etc., a linear encoder is used as the base 30. At the same time as monitoring and mounting at the four corners, feedback control. When jacking down, the proportional flow control valve is controlled based on the displacement signal from the linear encoder, and jacking down is performed while synchronizing.

As for the horizontal load, assuming that an axial force of 360 kN is introduced into the tension applying jack 39 as described above, the tension TI acting per one wire rope 34 is:
T1 = 360 kN / (4 lines × double) = 45 kN / line.
In addition, the maximum tension T2 acting on one wire rope 34 when the horizontal force is applied is:
T2 = 90 kN / line.
Here, when 360 kN is introduced into the tension applying jack 39 when the horizontal force is 0 kN, both the wire 34 a (−) and the wire 34 a (+) become 45 kN. When, for example, 250 kN acts in the x (−) direction, the wire 34a (+) becomes 0 kN, but the wire 34a (−) becomes 90 kN. Since there are four wires 34a (−) in the illustrated example, the axial force of the tension applying jack 39 is
90kN = 2x2 double = 360kN
It becomes.
Therefore, it is possible to follow the jack-up / jack-down of the lifting / lowering jack 32 by controlling using the relief valve so as to keep the axial force of the tension applying jack 39 constant. When the elevating jack 32 is stationary, the hydraulic circuit is shut off and the axial force is maintained to cope with the horizontal force.
In this way, it is possible to absorb the horizontal load following the lifting / lowering jack device even during the operation when it is raised or lowered.

In the first embodiment, as shown in FIG. 3, one wire 34 a (+) and one wire 34 a (−) are arranged on both sides of the tension applying jack 39 in one x-direction horizontal load absorbing device 33 a. The tension is applied in a balanced manner, but theoretically, the tension may be one by one, or three or more in order to reduce the tension per one. The same applies to the y-direction horizontal load absorber 33b.
In addition, two x-direction horizontal load absorbers 33a and two y-direction horizontal load absorbers 33b are arranged, but the present invention is not limited to this. One unit or three or more units may be used. Also good. Furthermore, the number of the x-direction horizontal load absorber 33a and the y-direction horizontal load absorber 33b may be varied according to the horizontal load.

  In the first embodiment, as shown in FIG. 3, the directions in which the tension is generated in the x-direction horizontal load absorber 33a and the y-direction horizontal load absorber 33b are the x-axis direction and the y-axis direction orthogonal to each other. This is because the horizontal load can be generated in any direction of 360 degrees. However, the present invention is not limited to this, and when the direction in which the horizontal load is generated only needs to correspond to one direction, the horizontal load absorbing device 33 is installed only in the direction matched with that direction. Can do. Further, the direction in which the tension is generated in the x-direction horizontal load absorbing device 33a and the y-direction horizontal load absorbing device 33b is not a direction orthogonal to each other, and any direction can be used as long as they are installed at a certain angle.

In the first embodiment, as shown in FIGS. 1 to 3, the fixed sheave 35 and the movable sheave 36 are interposed in the middle portion of one wire 34a (+), and the middle portion of the other wire 34a (−). By interposing the direction change sheave 37, the fixed sheave 35, and the movable sheave 36, tension is generated in the opposite directions by one tension applying jack 39. However, the present invention is not limited to this, and the configuration of the fixed sheave 35, the movable sheave 36, and the tension applying jack 39 of one wire 34a (+), and the fixed sheave 35 and the movable sheave 36 of the other wire 34a (-). And the configuration of the tension applying jack 39 may be provided separately and independently.
In the first embodiment, as shown in FIGS. 1 to 3, the fixed sheave 35, the movable sheave 36, the direction changing sheave 37, and the tension applying jack 39 are attached to the base 30. Also good.

The state which raised the loading platform 31 of the horizontal load absorption apparatus in the raising / lowering jack apparatus by this invention is shown, (a) is a front view which shows the spanning state of wire 34a (-), (b) is wire 34a. It is a front view which shows the spanning state of (+). The state which lowered | hung the loading platform 31 of the horizontal load absorption apparatus in the raising / lowering jack apparatus by this invention is shown, (a) is a front view which shows the spanning state of wire 34a (-), (b) is wire 34a. It is a front view which shows the spanning state of (+). It is a top view which shows one Example of the horizontal load absorber in the raising / lowering jack apparatus by this invention. It is a front view which shows the conveyance state of the heavy article 10 by the conventional raising / lowering jack apparatus 11. FIG. It is a detailed front view of the raising / lowering jack apparatus 11 in FIG. It is a detailed top view of the raising / lowering jack apparatus 11 in FIG. It is a front view of the conventional raising / lowering jack apparatus 11 by the present applicant. FIG. 8 is a side view of FIG. 7. FIG. 8 is a plan view of FIG. 7.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Heavy article, 11 ... Lifting jack apparatus, 12 ... Carriage, 13 ... Base, 14 ... Cargo bed, 15 ... Cargo lift cylinder, 16 ... Link mechanism, 17 ... Pin, 18 ... Supporting point, 19 ... Link cylinder, 20 ... Bracket, 21 ... spherical bearing, 22 ... spherical bearing, 23 ... cross beam, 24 ... telescopic jack device, 25 ... link mechanism, 30 ... base, 31 ... loading platform, 32 ... lifting jack, 33 ... horizontal load absorbing device, 34 ... wire, 35 ... fixed sheave, 36 ... movable sheave, 37 ... direction changing sheave, 38 ... fixed end, 39 ... jack for tension application, 40 ... cylinder, 41 ... piston rod, 42 ... movable shaft, 43 ... fixed shaft 44 ... A fixed shaft.

Claims (7)

In a lifting jack device that lifts and lowers a loading platform on a platform with a lifting jack, a fixed sheave and a direction changing sheave are fixedly attached to either the base or the loading platform, and the fixed sheave and the direction changing sheave A movable sheave is movably disposed between them, and a tension applying jack is connected between the fixed shaft of the fixed sheave and the movable shaft of the movable sheave to generate a tension to face the horizontal load of the loading platform. Then , two ends of the pair of wires are fixed to the base and the loading platform, respectively, and the movable sheave from the fixed end on the fixed sheave side of one of the pair of wires. The direction of each of the fixed sheaves is reversed and is passed over the fixed end on the side where the fixed sheave is not attached. And by inverting the directions in the fixed sheave and redirecting sheave pass over the fixed end of the mounting non side of the fixed sheave, that allowed cross in an X shape as allowed to generate a tension in opposite directions A horizontal load absorbing device in a lifting jack device. The horizontal load absorbing device in the lifting jack apparatus according to claim 1, wherein one of the base and the loading platform is a base and the other is a loading platform . 2. The horizontal load absorbing device in the lifting jack apparatus according to claim 1, wherein one of the base and the loading platform is a loading platform and the other is a loading platform .   The horizontal load absorption in the lifting jack apparatus according to claim 1, 2 or 3, characterized in that the same number of two pairs of wires that generate tension in opposite directions are arranged on both sides of the tension applying jack. apparatus.   An x-direction horizontal load absorbing device in which the same number of two pairs of two wires that generate tension in opposite directions are arranged on both sides of the tension applying jack, and y having the same configuration as this x-direction horizontal load absorbing device 5. The horizontal load absorbing device in the lifting jack device according to claim 1, wherein the directional horizontal load absorbing device is disposed at an angle of about 90 degrees between the base and the loading platform. . In a lifting jack device that lifts and lowers a loading platform on a platform with a lifting jack, a fixed sheave and a direction changing sheave are fixedly attached to either the base or the loading platform, and the fixed sheave and the direction changing sheave A movable sheave is movably disposed between them, and a tension applying jack is connected between the fixed shaft of the fixed sheave and the movable shaft of the movable sheave to generate a tension to face the horizontal load of the loading platform. Then , two ends of the pair of wires are fixed to the base and the loading platform, respectively, and the movable sheave is fixed to the movable sheave from the fixed end of the fixed sheave of one of the pair of wires. The direction of each of the fixed sheaves is reversed so that the fixed sheave is not attached to the fixed end on the side where the fixed sheave is attached. By passing by inverting the directions in blanking the fixed sheave and the direction changing sheave over the fixed end of the mounting non side of the fixed sheave, allowed cross in an X shape as allowed to generate a tension in the opposite directions, the When the horizontal load does not act on the cargo bed, the same tension is applied to the pair of wires when the horizontal load acts on the cargo bed. The tension generated in one of the pair of wires in the two wires against the load increases, and the tension generated in the other decreases correspondingly and balances to a constant value. A horizontal load absorbing method in an elevating jack apparatus characterized by absorbing a horizontal load while following an operation.   An x-direction horizontal load absorbing device in which the same number of two pairs of two wires that generate tension in opposite directions are arranged on both sides of the tension applying jack, and y having the same configuration as this x-direction horizontal load absorbing device A directional horizontal load absorbing device is disposed at an angle of approximately 90 degrees between the base and the loading platform, and tension is applied via a relief valve between the pump connected to the tensioning jack. 7. The horizontal load absorbing method in the lifting jack apparatus according to claim 6, wherein the jack output is controlled to be kept constant.

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