JP3287447B2 - lift device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lifting device suitable for use in a monitoring device provided with a TV camera and a light.

[0002]

2. Description of the Related Art Conventionally, three methods of a lifting apparatus used for a moving vehicle, such as a belt-type lifting mechanism, a link-type lifting mechanism, and a pantograph-type lifting mechanism, have been considered.

FIG. 8 is a side external view of a belt type lifting device. The belt-type elevating device 80 uses a belt-type elevating mechanism, and includes a plate-shaped bed 81 on which a conveyed object can be placed and moved up and down, and belts 8 attached to four corners of the bed 81.
2. The other end of the belt 82 is attached to the periphery of four take-up pulleys 84 provided on a base 83 above the loading platform and suspended, and the take-up pulley 84 is rotated by some power source. The loading platform 81 is moved up and down.

A link type lifting mechanism is disclosed in Japanese Patent Application Laid-Open No. 63-235.
This is a mechanism used in the elevating device described in Japanese Patent Application Laid-Open No. 155/155, and FIG. 9 shows a general mechanism by a graphic symbol. The link type elevating device 90 includes a fixed portion 91 such as a ceiling,
The vehicle has a rail-shaped track 92 laid thereon and a traveling body 94 having wheels 93 rolling on the track 92.
Then, links 95a, 95b, and 9 are provided between the traveling body 94 and the moving unit pedestal 96 on which the conveyed object is mounted or mounted.
This is a mechanism in which two parallel four-bar links composed of 5c and 95d are combined, and the two are connected by a rope 97. According to this mechanism, the running body 94 and the moving unit pedestal 9 can be obtained by winding or unwinding the rope 97.
6 is configured to be able to be moved up and down in a vertical direction while maintaining a parallel positional relationship.

[0005] As a mechanism other than the above two mechanisms, there is a pantograph type elevating mechanism used in an elevating device as described in Japanese Utility Model Laid-Open No. 6-65388.

FIG. 10 is a diagram showing the construction of a lifting apparatus using a pantograph type lifting mechanism by using graphic symbols. The pantograph-type lifting device 100 includes a traveling vehicle 104 having wheels 103 at an upper portion so as to travel on a rail 102 attached to a fixed portion 101 such as a ceiling, and a parallel link mechanism attached to the traveling vehicle 104 and capable of moving up and down. 105, a moving unit pedestal 106 attached to the lowermost end thereof, and a wire 10 which is configured to be able to be wound up and down so as to move up and down.
7

[0007] The parallel link mechanism 105 comprises links 108a to 108f, which are six elements, and is attached to the traveling vehicle 104 by fixing one end of the link 108a to a fulcrum 109a which can freely rotate in one plane. One end of the link 108b is attached at a rotatable fulcrum 109b to a linear bearing 110b sliding on a linear shaft 110a integrally attached to the traveling vehicle 104. The relationship between the link 108a and the link 108b is such that they are arranged so that they intersect, and
Is rotatably supported.

A link 108c is connected to the other end of the link 108a.
Are rotatably fixed by a fulcrum 109d. A link 108d is provided at the other end of the link 108b as a fulcrum 1.
09e is rotatably supported by the shaft. Further, links 108a and 108d, and links 108b
And the link 108c are configured in parallel, and the link 108c
At the intersection of the link 108d with the link 108d.
Is arranged. Link 1 is at the other end of link 108d.
08e is pivotally supported by a rotatable fulcrum 109g, and is disposed parallel to the link 108c. Link 108c
The other end is integrally attached to the movable base 106 at a fulcrum 109h pivotally supported.

The link 108e has a rotatable fulcrum 109i at the other end. Link 1 having one end connected to this fulcrum 109i and arranged in parallel with link 108d
08f has the other end connected to a rotatable fulcrum 109j on the link 108c.
08f constitutes a parallel link (four-bar rotating chain).

The fulcrum 109i is formed integrally with a linear bearing 110c formed integrally with the moving part pedestal 106, and moves along the linear shaft 110d.
Performs a linear motion accompanying the vertical motion of the robot.

As described above, the parallel link mechanism constituted by the fulcrums 109c to 109j and the links 108a to 108f can raise the moving unit pedestal 106 by winding the wire 107 by a winch.
In this case, the movement of the fulcrum 109a is only rotation, and the link 1
08a rotates in a direction approaching the traveling vehicle 104, and the fulcrum 1
09b rotates together with the link 108b, and moves rightward on the linear shaft 110a.

A fulcrum 109h on the moving part pedestal 106 side rotates in a direction in which the link 108c approaches the moving part pedestal 106, a fulcrum 109i rotates with the links 108e and 108f, and a linear bearing 110c is
Move right on 0d.

According to this mechanism, since the fixed portion 101 and the moving portion pedestal 106 are kept parallel and have rigidity, it is possible to travel with the moving portion pedestal 106 lowered.

[0014]

The above-mentioned belt type elevating mechanism has a small structure as a whole and has a simple structure. However, the rigidity in the direction perpendicular to the elevating direction is extremely low. In the case of transporting by hand, there is a problem that the inertia at the time of starting and stopping the running causes a shake. For this reason, it is necessary to take a procedure such that the transport of the load is performed after the load is raised and the transported product is fixed, which is an obstacle to shortening the transport time in the process.
Furthermore, it cannot be used outdoors due to the effects of crosswinds caused by gusts.

In the link type elevating mechanism, although the moving part pedestal does not incline and the conveyed object does not drop, it swings due to the inertia at the time of driving or stopping, so that it is similar to the belt type elevating mechanism. There is a defect that the parallel four-bar link must be run in a contracted state. Also, outdoor use cannot be performed for the same reason as the belt type lifting mechanism.

Further, the pantograph type lifting mechanism shown in FIG. 10 has a drawback that the force applied to the fulcrum 109a and the fulcrum 109b fluctuates due to the elevating operation and becomes an excessive value. Specifically, it is as follows.

The distance between the fulcrum 109a and the fulcrum 109b is assumed to be W,
Assuming that the distance between the fulcrum 109a and the fulcrum 109h (moving part pedestal 106) is H, the force applied to the moving part pedestal by the acceleration at the start of traveling is F1, and the load applied to the fulcrum 109b is F2, the moment around the fulcrum 109a is balanced. Gives the following equation:

[0018]

(Equation 1)

Here, when the moving unit pedestal 106 descends,
The distance H increases and the distance W decreases. Therefore, F2 will further increase. Although it is necessary to increase the distance H, it is not desirable to decrease the distance W from the viewpoint of minimizing the load applied to the device. Fulcrum 109a, fulcrum 1
As for the strength of 09b, a design value must be determined in the state where F2 is the largest, which results in an increase in the size, weight, and cost of the apparatus.

The second drawback is that the linear bearings 110b and 110c provided on each of the traveling vehicle 104 and the moving part pedestal 106, and the linear shafts 110a and 110a are provided.
It relates to a portion that slides linearly in combination with 110d. There are two types of linear bearings: rolling type and sliding type, both of which are advantageous in terms of accuracy and rigidity. In places where there is a lot of dust, dust prevention measures must be taken.

In addition to using the combination of the linear bearing and the linear shaft as described above for the linear sliding portion,
There is also a method using a combination of a roller and a guide. FIG.
Reference numeral 1 denotes a roller type slide mechanism including a roller and a guide installed on the moving unit base 106. The roller slide mechanism 111 includes a plate-like guide 113 having an elongated hole 112 and a roller 114 that rolls in the elongated hole 112. The guide 113 is provided on the moving unit base 106.
And a roller 114 that rolls around the fulcrum 109i, which is a rotation axis, inside the elongate hole 112, the elongate hole 112 including the range of the trajectory of the linear motion of the fulcrum 109i. The fulcrum 109i rotatably supports the link 108e and the link 108f, and linearly moves in the left-right direction by the rolling of the roller 114 accompanying the elevation of the moving unit base 106.

In this mechanism, a clearance S is naturally required between the roller 114 and the linear portion at the top of the elongated hole 112. However, this clearance acts as a mechanical backlash during operation (during running and lifting / lowering of the lifting / lowering device). ) Will have a negative effect. Although the clearance S can be made as small as possible, there are problems that high processing accuracy is required and that a malfunction occurs due to invasion of foreign matter. Either of the linear bearing and the roller type slide mechanism increases the cost and cannot be used outdoors or in places with much dust.

In addition to the above, as a third problem, in FIG. 10, in the movement of the linear bearings 110b and 110c caused by the vertical movement of the lifting / lowering device, the linear shafts 110a and 110d are installed in this movement range. Yes, other parts and devices cannot be placed. Specifically, a wire 107 is provided inside the traveling vehicle 104 at the top.
A mechanism such as a winch or a hoisting drum must be provided to wind up the linear bearings.
The device cannot be installed in the moving range of 10b (the place where the linear shaft 110a is placed).

The present invention has been made to solve these problems, and an object of the present invention is to provide a lifting device that realizes the following. 1. Ability to maintain rigidity against acceleration / deceleration and wind pressure during running, and to be able to run / stop even when lowered. 2. There should be no movement of the fulcrum using a linear sliding mechanism even when performing the elevating operation. 3. There must be no space restrictions regarding component placement.

[0025]

In order to solve the above-mentioned problems, the invention according to claim 1 is based on a first large link and a second large link that form a pair of long sides having the same length. A first four-bar rotating chain composed of four links each having a pair of first small links and second small links forming short sides of the same length facing each other, and a first link forming a pair of long sides. A second four-bar rotating chain composed of four links in which three large links and a fourth large link, and a third small link and a fourth small link that form a pair of short sides are respectively opposed to each other; A driving device for raising and lowering the link, fixing the first small link to an installation reference plane, and integrally forming the second small link and the third small link to form a first and second four-bar rotation A parallel link mechanism is formed by the chain, and the first large link, the third large link, and the third large link An approximate linear motion mechanism of watts is formed by a link having one end rotatably supported at a fixed point on an extension line provided on the body and the other end rotatably supported on the installation reference plane. It is characterized by.

According to a second aspect of the present invention, in the lifting device according to the first aspect, the installation reference plane is movable in a horizontal direction.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an external view of a monorail type monitoring device using a lifting device according to a first embodiment of the present invention in a state where the lifting device is raised to the uppermost position. FIG. 2 is a diagram in which the lifting device of FIG. 1 is lowered to the lowermost position. FIG. 3 is an external view of the moving unit pedestal side in the state, and FIG.

The monorail type monitoring device is for traveling on a rail installed in a building or outdoors, capturing an image of a subject with a camera, transmitting the image to a remote place, and performing monitoring.

A traveling body 3 is mounted on a rail 2 having an E-shaped cross section attached to a fixed portion 1 such as a ceiling so as to be movable on the rail 2. A link, that is, an elevating device 4 composed of 4a to 4h constitutes a mechanism to be described below, and a moving unit pedestal 5 is connected to the lowermost end of the lower portion of the traveling body 3. The traveling body 3 and the moving part pedestal 5 are connected by a wire 6, and inside the traveling body 3, a wire 6
(Not shown) and a motor (not shown) that rotates the drum to wind and unwind the wire 6
The vertical movement of the lifting / lowering device 4 is performed by this.

In FIG. 3, a traveling body 3 is fixed to a rail 2 so as to be sandwiched between wheels 10a to 10d, and is configured to be able to move on the rail 2 by rotation of the wheels 10a to 10d. The driving of the wheels 10 a to 10 d is performed by a driving motor (not shown) in the traveling body 3.

A camera platform 7 (FIG. 3) is attached to the lower part of the moving unit pedestal 5 for tilting and panning, and a TV camera 8 is provided on the side thereof, and the TV camera 8 is captured on the other surface. A light 9 for illuminating the subject is provided. The TV camera 8 can capture an arbitrary subject by the traveling movement of the traveling body 3, the vertical movement of the lifting / lowering device 4, and the operation of the camera platform 7.

The operation of the traveling body 3, the lifting device 4, the pan head 7 and the like can be arbitrarily operated from an operation panel (not shown), and if the position of the monitoring target is set in advance,
An automatic operation function is also provided in which a series of operations are automatically performed simply by specifying the target, and the image is quickly captured. The power supply and the transmission of the video signal and the control signal are performed via the sliding transmission line 77 (FIG. 3).

FIG. 4 is a skeleton diagram of the elevating mechanism showing the state of the elevating device according to the present embodiment at the time of descent, and FIG. 5 shows the state of the elevating device of FIG. 4 at the time of elevating. The elevating mechanism 40 of this embodiment is a combination of a parallel link mechanism and an approximate linear mechanism of watts.
1, the links 4a to 4 rotatably connected thereto
h, and fulcrums 41a to 41 that rotatably support them.
e, 41g to 41j, and a moving unit base 5 for mounting the camera platform 7, the TV camera 8, and the light 9.

The links constituting the parallel link mechanism of the elevating mechanism 40 are composed of a first four-bar chain 40a and a second four-bar chain 40b. 4th bar rotating chain 40a
And a first large link 4a and a second large link 4b rotatably attached to the installation reference surface 41 and a pair of short sides having the same length. 1 small link 4e (installation reference plane 4 forming a fixed link)
1) and the second small link 4f.

The second four-joint rotary chain 40b has the same configuration as the first four-joint rotary chain 40a, and includes a third large link 4c and a fourth large link 4d forming a pair of long sides, and a pair of short sides. And the third small link 4f integrally formed with the second small link 4f and the moving section pedestal 5 as a fourth small link.

The first and second four-bar rotating chains 40a, 4
0b form a parallel link mechanism, and the first large link 4a,
A third large link 4c, and a fifth link 4h rotatably supported at a fixed point (fulcrum 41g) on the extension of the third large link 4c and rotatably supported by the installation reference surface 41. Form an approximate linear motion mechanism of Watts.

One end of each of the first large link 4a, the second large link 4b, and the fifth link 4h is rotatably attached to a respective fulcrum 41c, 41a, 41b provided on the installation reference surface 41, and The other ends of the link 4a and the second large link 4b are rotatably supported by fulcrums 41e and 41d provided on a substantially triangular second small link 4f.

The other end of the first large link 4a is located at the intermediate point of the third large link 4c, and the fulcrum 4 on the second small link 4f
1e is rotatably supported by the shaft. The third large link 4c has a fulcrum 41i on the moving unit pedestal 5, and the fulcrum 4 which is an intermediate point.
A fulcrum 41g is provided at the other end opposite to the fulcrum 41i with respect to 1e, and one end of a fifth link 4h is rotatably supported at this point, and a rotatable fulcrum is provided at the other end of the fifth link 4h. 41b is provided and integrally fixed to the installation reference surface 41. In addition,
The fulcrum 41g is formed independently of the second small link 4f.

In FIG. 4, the first large link 4a, the second large link 4b, the third large link 4c, the fifth link 4h, and their fulcrums 41b and 41c constitute an approximate linear motion mechanism of watts. In this mechanism, when the distances between the fulcrums are set in the following equation, the fulcrum 41i performs a linear approximation motion.

[0040]

(Equation 2)

In an actual design, an optimum value of the length of each link is obtained by a motion trajectory analysis program capable of performing a simulation while changing the size of each link.

The approximate linear motion mechanism of watts determined in this way can make the trajectory of the vertical movement by the raising and lowering operation of the fulcrum 41i into an approximate straight line. However, since the installation reference plane 41 and the moving unit pedestal 5 cannot be maintained in a parallel state, the TV camera 8 attached to the moving unit pedestal 5 tilts the camera platform 7 each time the moving unit pedestal 5 moves up and down. It is necessary to capture the subject within the field of view. In order to eliminate such inconveniences, it is necessary to provide a mechanism that maintains the parallelism between the installation reference surface 41 and the moving unit pedestal 5 within a certain allowable range.

As a mechanism for maintaining such a constant degree of parallelism and performing linear approximation of the trajectory of the fulcrum 41i in the case of vertical movement, a parallel link mechanism is used in addition to the above-described approximate linear motion mechanism of watts. The combined mechanism of FIG. 4 was contemplated.

The parallel link mechanism (the first four-joint rotary chain 40a and the second four-joint rotary chain 40) used in this embodiment is used.
In b), since the line segment connecting the fulcrums 41a, 41c, 41e, and 41d forms a parallelogram, the fulcrums 41a, 41
1c, that is, when the installation reference plane 41 is fixed, the fulcrum 4
The line connecting 1d and 41e is always parallel to the line connecting the fulcrums 41a and 41c. The fulcrums 41h, 41j, 4
Since the line connecting 1i and 41e also forms a parallelogram,
The line connecting the fulcrums 41h and 41e is always the fulcrums 41i and 4e.
It becomes parallel to the line connecting 1j. Further, fulcrums 41d, 41
Since the positional relationship between e and 41h is not changed by the second and third small links 4f, when the moving part pedestal 5 is fixed to the fulcrums 41i and 41j so as to be parallel to the installation reference plane 41, FIGS. As shown, no matter what position (height) the moving unit pedestal 5 is at, it is parallel to the installation reference plane 41.

FIG. 6 is a diagram showing the motion locus of the moving part pedestal 5 when the elevating device of this embodiment moves from the ascending state to the descending state. By combining the above-mentioned approximate linear motion mechanism with Watt and this parallel link mechanism, as shown in the motion trajectory 60, the moving unit pedestal 5 moves up and down almost vertically while maintaining parallel to the installation reference plane 41. Is possible.

FIG. 7 is a skeleton diagram of the second embodiment of the present invention. In the following description, the same members as those in FIG. 4 are denoted by the same reference numerals. The lifting mechanism 70 uses a watt approximate linear motion mechanism including the first large link 4a, the fifth link 4h, and the third large link 4c shown in FIG. A pulley 72 and a smaller diameter pulley 73 are coaxially disposed on the
4 are arranged. Here, the pulley 71 and the pulley 72 have the same diameter, and the pulley 73 having a smaller diameter is
4 and the same diameter.

Since the pulley 71 is fixed to the installation reference surface 41, it does not rotate, and the pulleys 72 and 73 arranged coaxially with the fulcrum 41e are rotatable about the fulcrum 41e. It is configured. Pulleys 72, 7
3 performs the same function as the link 4f (FIG. 4) of the first embodiment. The pulley 74 is formed integrally with the moving section pedestal 5, rotates together with the pulley 74, and
It is configured to be always parallel to 1.

A belt 75 is wound between the pulley 71 and the pulley 72, and a belt 76 is wound between the pulley 73 and the pulley 74.

Since the pulley 71 and the pulley 72 have the same diameter, the first large link 4a and the belt 75 are kept parallel. Belt 75, pulley 71, first large link 4
a, the pulley 72 constitutes a parallel link, and a belt 75 is equivalent to the second large link 4b in FIG. Similarly, since the pulley 73 and the pulley 74 also have the same diameter, the third large link 4c and the belt 76 are kept parallel. Belt 76, pulley 73, third large link 4
c, the pulley 74 also forms a parallel link, and a belt 76 corresponds to the fourth large link 4d in FIG.

Therefore, in the lifting mechanism according to the second embodiment, the moving part pedestal 5 is always installed irrespective of the degree of lifting and lowering by the combination of the approximate linear motion mechanism of watts and the parallel link mechanism as in the first embodiment. It becomes parallel to the reference plane 41.

The pulley and belt of the second embodiment are
A sprocket and a chain, a timing belt and a toothed pulley may be used.

In both the first embodiment and the second embodiment, a pair of link mechanisms are arranged symmetrically as viewed from the side (see FIG. 3). This is to make the rigidity uniform.

[0053]

As described above, according to the first aspect of the present invention,
Since the parallel link mechanism including the first four-bar rotating chain and the second four-bar rotating chain and the approximate linear motion mechanism of watts are combined, the parallel link mechanism allows the installation reference plane and the fourth small link to be connected. Is always kept in a parallel state, and the trajectory of ascending and descending is approximately drawn by a straight line by the approximate linear motion mechanism of Watt.

Therefore, a relatively expensive linear bearing for moving the fulcrum of the link during the elevating operation as in the conventional pantograph type elevating mechanism is not required. Therefore, the manufacturing cost can be reduced and the device can be used in a bad environment such as outdoors. Further, since the number of links is increased as compared with the case where only the parallel link mechanism is used, the rigidity is increased, and the shaking of the TV camera or the like can be suppressed.

Since the fulcrum of the link on the installation reference plane does not move even when the elevating operation is performed, other parts and devices can be arranged in the conventional fulcrum movement range, and the degree of freedom in arranging the parts is expanded. Further, all the movable parts can be constituted by a rotary motion system, so that an inexpensive and highly reliable elevating device can be realized. In addition, since the distance between the fulcrums of the links on the installation reference plane side does not decrease when the elevating device descends, it is sufficient to set the distance between the fulcrums so that the force applied to these fulcrums is as small as possible. Since it is easier to secure the strength, it is possible to reduce the size and weight of the device and reduce the manufacturing cost.

When the installation reference plane is moved in the horizontal direction as described in claim 2, that is, when the elevating device of the present invention is applied to a moving vehicle or the like, a belt type elevating mechanism or a link type elevating mechanism is used. Since the stiffness is higher, stable running is possible even when the elevating device is lowered, and there is no influence of wind pressure outdoors. Therefore, in an application in which a monitoring device equipped with a TV camera is moved, a stable image without disturbance can be obtained. At the same time, deflection due to inertia acting on the elevating device at the time of starting or stopping the running is small, and shaking is unlikely to occur.

Further, when the present invention is used for transporting articles, there is no need to raise the elevating device at the time of transport, so that the work is not complicated and the transport time in the process can be shortened. Further, since the weight of the lifting device can be reduced, the inertia force at the time of starting and stopping the running is reduced, so that the running and stopping can be performed smoothly, and the transportable weight can be increased.

[Brief description of the drawings]

FIG. 1 is an external view of a monorail type monitoring device using a lifting device according to a first embodiment of the present invention, in a state where the lifting device is raised to the uppermost part.

FIG. 2 is an external view of the moving unit pedestal side in a state where the lifting / lowering device of FIG. 1 is lowered to a lowermost end.

FIG. 3 is a view as seen in the direction of arrow III in FIG. 1;

FIG. 4 is a skeleton diagram of a link mechanism showing a state of the elevating device according to the present embodiment when the elevating device descends.

FIG. 5 is a skeleton diagram showing a state of the lifting device shown in FIG. 4 at the time of lifting.

FIG. 6 is a diagram illustrating a motion locus of a moving unit pedestal when the elevating device according to the present embodiment moves from an ascending state to a descending state.

FIG. 7 is a skeleton diagram illustrating a lifting mechanism that constitutes a part of a parallel link mechanism using a belt and a pulley according to a second embodiment of the present invention.

FIG. 8 is a side external view of a belt type elevating device.

FIG. 9 is a diagram showing a general mechanism of a link type elevating device by a graphic symbol.

FIG. 10 is a configuration diagram of a lifting device using a pantograph-type lifting mechanism by using graphic symbols.

FIG. 11 shows rollers and guides installed on a moving unit base.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Fixed part 2 Rail 3 Traveling body 4 Elevating device 4a First large link 4b Second large link 4c Third large link 4d Fourth large link 4e First small link 4f Second small link, third small link 4g Fourth small Link 4h Fifth link 5 Moving unit pedestal 6 Wire 7 Head 8 TV camera 9 Light 10a, 10b, 10c, 10d Wheel 40, 70 Lifting mechanism 41 Installation reference plane 41a, 41b, 41c, 41d, 41e, 41g, 4
1h, 41i, 41j Support point 60 Motion trajectory 71, 72, 73, 74 Pulley 75, 76 Belt 77 Sliding transmission path

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-7-214482 (JP, A) JP-A-4-226878 (JP, A) JP-A 51-127578 (JP, U) JP-A 6-214482 65388 (JP, U) Fully open Showa 60-110755 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16H 19/00-31/00 B66F 19/00 H04N 5/222

Claims (2)

(57) [Claims] 1. A first large link and a second large link forming a pair of long sides having the same length, and a first small link and a second small link forming a pair of short sides having the same length. A first four-bar rotating chain composed of four links each of which is opposed to each other; a third large link and a fourth large link forming a pair of long sides; a third small link forming a pair of short sides; A second four-bar rotating chain composed of four links each having a fourth small link opposed to each other, a driving device for raising and lowering the fourth small link, and fixing the first small link to an installation reference plane; Further, the second small link and the third small link are integrally formed to form a parallel link mechanism by first and second four-bar rotating chains, and the first large link, the third large link, and the One end is rotatably supported at a fixed point on an extension line provided integrally with the three large links, and the other end is By a rotatably supported link to location reference plane, lifting apparatus and forming a watt approximate linear motion mechanism. 2. The elevating device according to claim 1, wherein the installation reference plane is movable in a horizontal direction.