JP6952505B2 - Hoisting machine device with casters and hoisting machine stand with casters - Google Patents

Description

The present invention relates to a hoisting machine and a hoisting machine device including a hoisting machine stand in an elevator. The present invention also relates to a hoisting machine stand.

As described in Patent Document 1, in an elevator having a machine room, the hoisting machine is usually fixed to the upper surface of the hoisting machine stand, and the hoisting machine stand is arranged on the floor surface of the machine room. It is fixed on the machine base (machine beam). The hoisting machine stand is provided, for example, for mounting the hoisting machine on a horizontal plane having higher horizontal accuracy.

International Publication No. 2013-179423

If the elevator has a machine room at the top of the hoistway, the hoist is carried to the machine room and centered, for example: Specifically, first, the hoisting machine is lifted to the roof of the building at the site by a crane. Next, the hoisting machine is carried from the roof to the machine room. There is one or more steps in the carry-in route of the hoisting machine from the roof to the machine room.

To move the hoisting machine to the lower side of the step, place the hoisting machine on the trolley, pull the trolley sideways, and move the trolley on which the hoisting machine is mounted to the upper side of the step. Then, the hoisting machine is lifted directly above the lower part of the step by a chain block or the like, then the dolly is moved below the hoisting machine, and then the hoisting machine is lowered by the chain block and below the step. Place it on the dolly that has been moved to the side.

This work is repeated every time there is a step. When the hoisting machine is transported to the machine room, the dolly on which the hoisting machine is mounted is moved by pulling it sideways to the vicinity of the setting place of the hoisting machine. After that, the hoisting machine is lifted by the chain block, then lowered, and placed in the very vicinity of a predetermined position.

The hoisting machine is aligned at a predetermined position with high accuracy in millimeters so that the wire rope is not tilted in the vertical direction and is centered. Alignment in millimeters is performed by, for example, a skilled worker finely moving the hoist by applying a local impact to the hoist.

The hoisting machine must always be moved from the warehouse to a predetermined position in the machine room together with the dolly, and each time the hoisting machine is lifted to overcome an obstacle, the dolly must be moved in advance. be. Therefore, a great deal of man-hours and labor are required to move the hoisting machine.

In addition, if the hoisting machine is placed on the bogie with the center of gravity of the hoisting machine far away from the center of gravity of the bogie, the bogie may tilt, and it takes time to adjust the bogie position to an appropriate position. It takes.

Further, it is preferable that the centering of the hoisting machine can be easily and smoothly performed without applying a local impact.

Therefore, an object of the present invention is to provide a hoisting machine device and a hoisting machine stand which can move the hoisting machine more easily, smoothly and in a short time, and can easily and smoothly center the hoisting machine. To provide.

In order to solve the above problems, the hoisting machine device according to the present disclosure includes a rope wheel around which the rope of the elevator is wound and an electric motor for rotating the rope wheel, and is opened downward and in the height direction. A main body having an extending caster storage portion, a protruding position where at least the lower portion in the height direction projects downward from the main body portion in the height direction, and all the portions are in the caster storage portion. It is provided with a caster capable of moving in the height direction between the storage positions to be stored, and a caster moving mechanism for moving the caster between the protruding position and the storage position in the height direction.

According to the present disclosure , the hoisting machine device has casters whose lower portion projects downward from the main body in the protruding position, and the hoisting machine device can be moved by the casters. Therefore, it is not necessary to carry the trolley at all to move the hoisting machine device, and the hoisting machine device can be moved more easily, smoothly and in a short time.

In addition, even when centering the hoisting machine device to precisely position it in a predetermined position, the hoisting machine device can be executed in a movable state with casters, without applying an excessive force to the hoisting machine device. The hoisting machine device can be easily moved to a predetermined position. Therefore, centering of the hoisting machine device can be performed more easily and smoothly.

Further, the casters can be stored in the storage position by using the caster moving mechanism in a state where the hoisting machine device is positioned at a predetermined position. Therefore, after centering the hoisting machine device, the bottom surface of the hoisting machine device can be easily brought into contact with the machine base (machine beam), and the hoisting machine device can be stably and surely attached to a predetermined position.

Further, in the present disclosure , the hoisting machine including the sheave and the electric motor and the hoisting machine are mounted on the main body, and the hoisting machine is arranged between the hoisting machine and the machine base. The machine base is included, and the caster storage portion may be provided on the hoisting machine base.

The hoisting machine device may be moved (conveyed) while the hoisting machine is fixed to the hoisting machine base by a fastening member. According to the above configuration, in such a case, the hoisting machine can be moved more easily, smoothly and in a short time, and centering can be easily and smoothly performed.

Further, in the present disclosure , the main body portion is composed of a hoisting machine including the sheave and the electric motor, and the hoisting machine is mounted on the machine base without passing through the hoisting machine base, and the caster storage portion. May be provided in the hoisting machine.

The hoist may be mounted directly on the machine base without going through the hoist base. According to the above configuration, in such a case, the hoisting machine can be moved more easily, smoothly and in a short time, and centering can be easily and smoothly performed.

Further, in the present disclosure , the caster moving mechanism extends in the height direction including a caster mounting portion on which the casters are rotatably mounted and a tip portion integrated with an upper end portion of the caster mounting portion. You may have a bolt to be used and a jack bolt including a nut fixed to the main body and screwed into the bolt.

According to the above configuration, the caster moving mechanism can be easily and inexpensively configured.

Further, in the present disclosure , the casters have a spherical shape, the casters are rotatably attached to the caster mounting portion, and the caster mounting portion has a circular shape having a diameter smaller than the diameter of the casters. The lower plate portion having an opening and the upper block portion which is composed of a part of a spherical surface and has a facing surface facing the upper spherical portion of the caster in the radial direction and is fixed to the lower plate portion and the facing surface. A plurality of balls disposed between the surface and the upper spherical surface portion may be included.

According to the above configuration, the caster moving mechanism can be smoothly moved in a desired direction in comparison with the wheel type casters.

Further, the hoisting machine stand according to the present disclosure is a hoisting machine base on which a hoisting machine is mounted in an elevator, and has a caster storage portion that opens downward and extends in the height direction. Between the main body and a protruding position in which at least the lower portion in the height direction protrudes downward in the height direction from the machine base main body and a storage position in which all the portions are stored in the caster storage portion. The caster is movable in the height direction, and the caster moving mechanism for moving the caster between the protruding position and the storage position in the height direction is provided.

According to the present disclosure , the hoisting machine can be moved more easily, smoothly and in a short time by carrying and centering the hoisting machine while the hoisting machine is mounted on the upper mounting surface. The hoisting machine can be centered easily and smoothly.

According to the hoisting machine device and the hoisting machine stand according to the present invention, the hoisting machine can be moved more easily, smoothly and in a short time, and the hoisting machine can be centered easily and smoothly. ..

It is a schematic front view when the hoisting machine device which concerns on one Embodiment of this invention is seen from the side opposite to the sheave arrangement side. It is a schematic side view when the hoisting machine apparatus is seen from the direction shown by the arrow A in FIG. It is a schematic diagram for demonstrating the structure of the R part of FIG. 1 in more detail. It is a schematic diagram for demonstrating the structure of part S of FIG. 2 in more detail. It is a schematic plan view when the jack bolt of the caster mounting part of the hoisting machine device is seen from the top. It is a schematic plan view corresponding to FIG. 5 in the hoisting machine apparatus of a modification.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. When a plurality of embodiments and modifications are included in the following, it is assumed from the beginning that a new embodiment is constructed by appropriately combining the characteristic portions thereof. Further, in the following description and drawings, the X direction represents the width direction of the hoisting machine device 1 (winding machine base 30), and the Y direction is the depth direction of the hoisting machine device 1 (winding machine base 30). The Z direction represents the height direction of the hoisting machine device 1 (the hoisting machine base 30). The X, Y, and Z directions are orthogonal to each other.

FIG. 1 is a schematic front view of the hoisting machine device 1 according to the embodiment of the present invention when viewed from the side opposite to the sheave arrangement side, and FIG. 2 shows the hoisting machine device 1 in FIG. It is a schematic side view when viewed from the direction shown by arrow A.

The hoisting machine device 1 is arranged and fixed on, for example, a machine table provided on the floor surface of the machine room above the hoistway of the elevator or the floor surface of the pit below the hoistway. As shown in FIG. 1, the hoisting machine device 1 includes a main body 2, casters 3, and a caster moving mechanism (hereinafter, simply referred to as a moving mechanism) 4, and the main body 2 is a hoisting machine 10 and hoisting. It has an upper machine base 30. The bottom surface 21 of the hoisting machine 10 and the top surface 22 of the hoisting machine base 30 each spread on an XY plane. With the bottom surface of the hoisting machine 10 mounted on the upper surface (mounting surface) of the hoisting machine base 30, the hoisting machine 10 is attached and fixed to the hoisting machine base 30 with bolts (not shown). NS.

As shown in FIG. 2, the hoisting machine 10 includes a sheave fixing base 11 and a sheave 12, and the sheave 12 is rotatably attached to the sheave fixing base 11. Specifically, the sheave 12 has a rotating shaft 13, and the rotating shaft 13 is fixed to the stationary portion 16 of the sheave fixing base 11 via a bearing 14 inside the sheave fixing base 11.

The hoisting machine 10 further includes an electric motor 17. The electric motor 17 is built in the sheave fixing base 11. The motor includes a rotor and a stator (not shown), the rotor rotating with respect to the stator. The output shaft of the rotor is located on the same straight line as the rotating shaft 13 of the sheave 12, and is integrated with the rotating shaft 13. A plurality of ropes (not shown) are wound around the plurality of rope grooves of the sheave 12. For example, one end of each rope is fixed to the upper part of a basket (not shown), and the other end of each rope is fixed to a balance weight (not shown).

By rotating the output shaft of the rotor based on the signal from the control unit of the elevator, the rotating shaft 13 rotates and the sheave 12 rotates. As the sheave 12 rotates, the rope moves from the basket side to the counterweight side, or moves from the counterweight side to the basket side, and as a result, the basket moves up and down. The electric motor may be arranged outside the sheave fixing base 11, or a speed reducer may be arranged between the output shaft of the electric motor and the rotating shaft of the sheave. Further, the portion of the rope on the balance weight side may be hung on a sheave fixed to the balance weight and then fixed to the ceiling of the hoistway.

The hoisting machine base 30 includes a machine base main body 31 made of an integral steel material, and the machine base main body 31 has an upper surface 22 on which the hoisting machine 10 is placed. As shown in FIG. 2, the machine base main body 31 includes a first I-shaped portion 32 having an I-shaped cross section and a second I-shaped portion 33 having an I-shaped cross section, and the first I-shaped portion 32 is in the Y direction. The second I-shaped portion 33 is arranged on one side and extends in the X direction, and the second I-shaped portion 33 is arranged on the other side in the Y direction and extends in the X direction. The first I-shaped portion 32 and the second I-shaped portion 33 may be connected by one or more connecting portions 35, 36 extending in the Y direction, and in this case, the handleability of the hoisting machine base 30 can be improved. Is preferable. It should be noted that one or more connecting portions 35, 36 do not have to exist, and the machine base main body does not have to have an integrated structure. The machine base body of the hoisting machine base may have any shape and structure as long as it has an upper surface and a bottom surface extending on an XY plane, and may have, for example, a flat plate shape.

As shown in FIGS. 1 and 2, the hoisting machine device 1 includes four casters 3 and four moving mechanisms 4. Each moving mechanism 4 is provided to move one caster 3 up and down in the Z direction. The caster assembly including the caster 3 and the moving mechanism 4 is arranged at the lower end of the hoisting machine device 1 in the Z direction and at the corner (corner) in the XY direction.

Next, the caster 3 and the moving mechanism 4 will be described in detail with reference to FIGS. 3 to 5. FIG. 3 is a schematic diagram showing the region indicated by R in FIG. 1 in more detail, and FIG. 4 is a schematic diagram showing the region indicated by S in FIG. 2 in more detail. Further, FIG. 5 is a schematic plan view of the moving mechanism 4 arranged in the region indicated by S when viewed from above in the Z direction.

As shown in FIGS. 3 and 4, the casters 3 have a spherical shape and are made of a metal material such as a steel material or a resin material such as a ceramic material. Further, the moving mechanism 4 has a caster mounting portion 41 and a jack bolt 42. The outer side of each moving mechanism 4 is covered with a covering plate 50. The covering plate 50 has an integral structure and has a substantially L-shaped shape in a plan view when viewed from above in the Z direction.

As shown in FIG. 3, the covering plate 50 includes a main body portion 51 and a flat plate-shaped first mounting portion 52. The first mounting portion 52 bends inward in the Y direction from one end in the X direction and the lower end in the Z direction of the main body 51. The first I-shaped portion 32 has an upper extending portion 32a and a lower extending portion 32b. The first mounting portion 52 is fixed to the lower extending portion 32b of the first I-shaped portion 32 with bolts 55.

As shown in FIG. 5, the covering plate 50 further has a second mounting portion 53. The second mounting portion 53 extends from the main body portion 51 to one side in the X direction. The second mounting portion 53 is fixed to the sliding plate 60 with bolts 56, and the sliding plate 60 is fixed to the Z-direction extending portion 38 (see FIG. 2) of the second I-shaped portion 33 with bolts 58. The second mounting portion 53 and the bolt 56 are located above the nut 68 of the caster mounting portion 41 in the Z direction. The nut 68 will be described in more detail later. The covering plate 50 is securely fixed to the machine base body 31 by fixing the first and second mounting portions 52, 53 to the machine base body 31 with bolts 55, 56, 58. The covering plate 50 is included in the hoisting machine base 30.

As shown in FIGS. 3 and 4, the caster mounting portion 41 is a block-shaped member. The caster mounting portion 41 has a hemispherical chamber 45 and a circular opening 46 on the lower side in the Z direction. The hemispherical chamber 45 communicates with the outside through a circular opening 46. The upper portion of the caster 3 is housed in the hemispherical chamber 45. The diameter of the hemispherical chamber 45 is larger than both the diameter of the caster 3 and the diameter of the opening 46, and the diameter of the opening 46 is slightly smaller than the diameter of the caster 3. As a result, the casters 3 cannot be separated from the caster mounting portion 41. The caster mounting portion 41 includes an upper block portion 81 having a hemispherical recess and a flat plate-shaped lower plate portion 82 having a circular opening 46, and the upper block portion 81 includes joining means, for example, an adhesive, a welded portion, and the like. It is fixed to the lower plate portion 82 by a fastening member or the like.

The caster mounting portion 41 further has a plurality of steel balls 48. The plurality of balls 48 are the same, and each ball 48 has a diameter smaller than the diameter of the caster 3. Each ball 48 is arranged between the upper spherical portion 83 of the caster 3 and the facing surface 84 of the upper block portion 81 facing the upper spherical portion 83. The facing surface 84 is composed of a part of a spherical surface. Each ball 48 is freely rotatable, and as a result, the caster 3 is rotatable.

The jack bolt 42 has a bolt 67 and a nut 68. The bolt 67 includes a tip portion 72 integrated with an upper end portion of the caster mounting portion 41. Further, as shown in FIGS. 4 and 5, the nut 68 is integrally formed with the sliding plate 60. Since the sliding plate 60 is fixed to the second I-shaped portion 33 as described above, the nut 68 is integrally formed with the hoisting machine base 30 and is stationary with respect to the hoisting machine base 30. As shown in FIG. 4, the nut 68 has a screw hole 76, and the screw hole 76 is screwed with a male screw provided on the shaft portion of the bolt 67.

The upper block portion 81 of the caster mounting portion 41 is fixed to the covering plate 50 by bolts 95. When the head 77 of the bolt 67 is rotated to one side by hand or a tool with the bolt 95 removed, the bolt 67 moves upward in the Z direction with respect to the nut 68, and as a result, is integrated with the bolt 67. The caster mounting portion 41 also moves upward in the Z direction. The hoisting machine base 30 has a caster accommodating portion 88 defined by a covering plate 50 and a sliding plate 60. The caster mounting portion 41 is gradually housed in the caster storage portion 88 as it moves upward in the Z direction.

On the other hand, when the head 77 of the bolt 67 is rotated to the other side by hand or a tool or the like, the bolt 67 moves downward in the Z direction with respect to the nut 68, and the caster mounting portion 41 also moves downward in the Z direction. The caster 3 has a protruding position in which a part of the caster 3 protrudes downward in the Z direction from the hoisting machine base 30, and a caster storage in which all parts are located above the lower end in the Z direction of the hoisting machine base 30 in the Z direction. It is possible to move between the storage position and the storage position stored in the unit 88. When the caster mounting portion 41 moves up and down, it slides on the sliding plate 60 and is guided by the sliding plate 60.

In the state shown in FIG. 4, the caster 3 is located at a protruding position in which a part of the caster 3 projects downward in the Z direction from the hoisting machine base 30. In this state, by fixing the covering plate 50 and the caster mounting portion 41 with the bolt 95, the state in which the caster 3 is positioned at the protruding position is stably maintained. Further, although not shown, by tightening the bolt 95 to the covering plate 50 and the caster mounting portion 41 while the caster 3 is located at the storage position, the state where the caster 3 is located at the storage position can be stably maintained. Can be maintained. By configuring the moving mechanism 4 by using the jack bolt 42, the moving mechanism 4 can be easily and inexpensively configured.

According to the above embodiment, the hoisting machine device 1 has casters 3 which partly protrudes downward from the hoisting machine base 30 in the Z direction at the protruding position, and the hoisting machine device 1 moves by the casters 3. Be free. Therefore, it is not necessary to carry the trolley at all to move the hoisting machine device 1, and the hoisting machine device 1 can be moved more easily, smoothly, and in a short time.

Further, even when centering the hoisting machine device 1 to be precisely positioned at a predetermined position, the hoisting machine device 1 can be executed in a movable state by the casters 3, and an excessive force is applied to the hoisting machine device 1. The hoisting machine device 1 can be easily moved to a predetermined position without doing so. Therefore, centering of the hoisting machine device 1 can be performed more easily and smoothly.

Further, in a state where the hoisting machine device 1 is positioned at a predetermined position, the caster 3 can be stored in the storage position by using the moving mechanism 4. Therefore, after centering the hoisting machine device 1, the bottom surface of the hoisting machine device 1 can be easily brought into contact with the machine base, and the hoisting machine device 1 can be stably and surely attached to a predetermined position of the machine base. ..

Further, the caster 3 has a spherical shape, and a plurality of balls 48 are arranged between the upper spherical portion 83 of the caster 3 and the facing surface 84 facing the upper spherical portion 83 in the upper block portion 81. .. Therefore, it is easy to move the casters 3 smoothly in a desired direction in comparison with the wheel type casters.

The present invention is not limited to the above-described embodiment and its modifications, and various improvements and modifications can be made within the scope of the claims of the present application and the equivalent scope thereof.

For example, in the above embodiment, the case where the hoisting machine device 1 includes the hoisting machine 10 and the hoisting machine base 30 and the hoisting machine 10 is fixed to the machine base via the hoisting machine base 30 will be described. The case where the caster storage portion 88 is provided on the hoisting machine base 30 has been described. However, the hoisting machine device does not have a hoisting machine stand, and the hoisting machine of the hoisting machine device may be directly mounted on the machine stand, or the hoisting machine may be provided with a caster storage portion. ..

Further, the case where the hoisting machine device 1 has the spherical casters 3 has been described. However, the hoisting machine device may have wheel-type casters used in a commercially available carriage, and the wheel-type casters may have a configuration in which the direction of the rotation axis can be freely changed.

Further, a case where the caster mounting portion 41 is fixed to the covering plate 50 with bolts 95 at the protruding position and the storage position has been described. However, as shown in FIG. 6, that is, the schematic plan view corresponding to FIG. 5 in the hoisting machine device 101 of the modified example, the caster mounting portion 141 has a flat plate-shaped mounting portion 185 at one end in the X direction. You may. Then, by fixing the mounting portion 185 to the sliding plate 160 with bolts 195, the caster mounting portion 141 may be fixed to the hoisting machine base 130 at the protruding position and the storage position.

Further, the case where the caster accommodating portion 88 is defined by the covering plate 50 and the sliding plate 60 has been described. However, the hoisting machine device does not have to have a covering plate. Then, at the storage position where the casters are located above the lower end in the Z direction of the main body of the hoisting machine device and are stored in the caster storage unit, the caster moving mechanism and the casters are visible from the outside. May be good. Further, the hoisting machine device does not have to have a sliding plate, and the caster mounting portion does not have to be guided by the sliding body when moving up and down in the Z direction. Further, a case where a part of the casters 3 is located below the main body 2 of the hoisting machine device 1 in the Z direction at the protruding position has been described. However, in the protruding position, all of the casters may be located below the main body of the hoisting machine device in the Z direction. Further, a case where the caster moving mechanism is configured by using the jack bolt 42 has been described. However, the caster moving mechanism may be configured by using an electric cylinder or a hydraulic jack.

1 hoisting machine device, 2 hoisting machine main body, 3 casters, 4 moving mechanism, 10 hoisting machine, 12 rope wheel, 17 electric motor, 30 hoisting machine stand, 31 machine stand main body, 41 caster mounting part, 42 Jack bolts, 48 balls, 67 bolts, 68 nuts, 81 upper block part, 82 lower plate part, 83 upper spherical part, 84 facing surface, 88 caster storage part, Z direction height direction.

Claims (5)

A main body including a sheave around which an elevator rope is wound and an electric motor for rotating the sheave, and having a caster storage portion that opens downward and extends in the height direction.
The height is at least between a protruding position in which the lower portion in the height direction projects downward from the main body portion in the height direction and a storage position in which all the portions are stored in the caster storage portion. With casters that can move in the direction
A caster moving mechanism for moving the casters between the protruding position and the storage position in the height direction is provided .
The main body includes a hoisting machine including the sheave and the electric motor, and a hoisting machine base on which the hoisting machine is mounted and arranged between the hoisting machine and the machine base. ,
The caster storage portion is provided on the hoisting machine stand, and is provided on the hoisting machine stand.
The caster moving mechanism includes a caster mounting portion on which the casters are rotatably mounted, and a tip portion integrated with an upper end portion of the caster mounting portion, and a bolt extending in the height direction and the main body portion. Has a jack bolt, including a nut, which is fixed to the bolt and screwed into the bolt.
The hoisting machine base has an upper extending portion and a lower extending portion extending in the width direction of the hoisting machine and extending at intervals in the height direction.
The nut is located between the upper extension and the lower extension with the nut spaced apart from both the upper extension and the lower extension in the height direction.
A hoisting machine device in which all parts of the casters are located above the lower end of the lower extending portion in the height direction while the casters are located at the storage position. In the hoisting machine device according to claim 1,
It is provided with a covering plate that is fixed to the lower extending portion and covers the outer side of the caster moving mechanism.
The covering plate and the caster mounting portion can be fixed with bolts while the casters are located at the protruding positions.
Even when the caster is located in the stowed position, that has become possible to fix the caster mounting portion and the cover plate with the bolts, hoist device. In the hoisting machine device according to claim 1,
The hoisting machine base has a height extending portion extending in the height direction.
It is provided with a sliding plate that is fixed to the extending portion in the height direction and is integrally formed with the nut.
The caster mounting portion slides on the sliding plate when moving up and down, and is guided by the sliding plate .
The caster mounting portion has a mounting portion on a flat plate that abuts on the sliding plate.
The projecting position and the caster mounting portion that looks like can be fixed on machine base in the winding in the stowed position, the hoist apparatus by fixing the sliding plate the attachment portion by bolts. In the hoisting machine device according to any one of claims 1 to 3.
The caster has a spherical shape and has a spherical shape.
The caster is rotatably attached to the caster attachment portion and is attached.
The caster mounting portion includes a lower plate portion having a circular opening having a diameter smaller than the diameter of the caster, and a surface facing the upper spherical portion of the caster in the radial direction, which is composed of a part of a spherical surface. A hoisting machine device comprising an upper block portion fixed to the lower plate portion and a plurality of balls disposed between the facing surface and the upper spherical surface portion. It is a hoisting machine stand on which a hoisting machine is placed in an elevator.
The machine base body, which has a caster storage part that opens downward and extends in the height direction,
The height is at least between a protruding position in which the lower portion in the height direction projects downward from the machine base body in the height direction and a storage position in which all the portions are stored in the caster storage portion. With casters that can move in the vertical direction
A caster moving mechanism that moves the casters between the protruding position and the storage position in the height direction, and
Equipped with a,
The caster moving mechanism includes a caster mounting portion on which the casters are rotatably mounted, and a tip portion integrated with an upper end portion of the caster mounting portion, and a bolt extending in the height direction and the main body portion. Has a jack bolt, including a nut, which is fixed to the bolt and screwed into the bolt.
The machine base main body has an upper extending portion and a lower extending portion extending in the width direction of the hoisting machine and extending at intervals in the height direction.
The nut is located between the upper extension and the lower extension with the nut spaced apart from both the upper extension and the lower extension in the height direction.
Hoisting machine base you located above the height direction from the lower end of all parts of the caster in the state in which the caster is positioned in the storage position the lower extending portion.

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