Loading device

Abstract

To provide an unloading device that can reduce the labor of an operator.SOLUTION: An unloading device 100 is used for unloading operations to move a cargo 200 between a lower floor FL and an upper floor FU at a construction site. The unloading device 100 includes a base section 10, a column section 16, a loading platform section 40, a motor 14 and a chain 30. The base section 10 is installed on the lower floor FL. The column section 16 is erected on the base section 10 and arranged to extend from the lower floor FL toward the upper floor FU. The loading platform section 40 is provided to be able to move up and down along the height direction of the column section 16 on which the cargo 200 is loaded. The motor 14 outputs power for moving the loading platform section 40 up and down. The chain 30 transmits the power of the motor 14 to the loading platform section 40.SELECTED DRAWING: Figure 1

Description

[[TECHNICAL FIELD]]

[0001] The present invention relates to a lifting apparatus. [[BACKGROUND ART]]

[0002] Conventionally, lifting apparatuses have been proposed (see, for example, Patent Document 1).

[0003] Generally, multi-story buildings such as apartment buildings and office buildings are constructed sequentially from lower floors (lower regions) to upper floors (upper regions). For example, when constructing a multi-story building of RC (Reinforced Concrete) structure or SRC (Steel Reinforced Concrete) structure, first the concrete structure of the 1st floor is constructed, and then the 2nd floor, the 3rd floor, and so on are constructed sequentially.

[0004] When constructing a building as described above, various materials including temporary construction materials (hereinafter collectively referred to as "cargo") are used. Specifically, a wide variety of materials and equipment are used, such as formwork used for concrete pouring, shoring for assembling formwork, single pipes (carbon steel pipes for general structural use) used for scaffolding and the like, joint materials (clamps and the like), scaffolding boards, as well as other wooden frames and metal fittings. When construction is carried out sequentially from lower floors to upper floors as described above, these cargos are sequentially lifted to upper floors every time construction of a lower floor is completed.

[0005] Conventionally, for transporting cargo from lower floors to upper floors, methods have been used such as having workers hand-carry the cargo through an opening provided in the floor of an upper floor, horizontally moving the cargo to a main staircase or external scaffolding staircase and then transporting it by another carrier, and horizontally moving the cargo to an external elevator and then transporting it. However, all these methods have various problems: the burden on workers is heavy, considerable working time is required for transportation, and when moving horizontally over a long distance, work to climb over partitions is required.

[0006] Therefore, various improved technologies for transporting cargo have been proposed to date. For example, Patent Document 1 discloses a lifting device that can lift cargo from a lower floor to an upper floor using machinery. This lifting device comprises a support column extending to connect the lower and upper floors, sprocket gears attached to the upper and lower parts of the support column, a chain stretched across the sprocket gears, and hooks attached to the chain for hanging cargo.

[0007] When using the above lifting device to transport goods from a lower floor to an upper floor, the goods are attached to hooks on the chain, and by pressing a switch, the chain rotates, causing the goods to rise from the lower floor to the upper floor. Then, a worker waiting on the upper floor detaches the goods from the hooks, completing the transport of the goods. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2009-270414 [Overview of the project] [Problems that the invention aims to solve]

[0009] However, the lifting device disclosed in Patent Document 1 above has the disadvantage that, because loads are hung on hooks attached to a chain and transported to upper floors, hanging heavy loads on the hooks is burdensome for the worker, and it is difficult to transport multiple loads at once. For this reason, there is a need for a lifting device that can further reduce the labor of the worker when transporting loads.

[0010] The present invention was made to solve the above-mentioned problems and aims to provide a lifting device that can reduce the labor of workers. [Means for solving the problem]

[0011] To achieve the above objective, the present invention is configured as follows.

[0012] (1) The lifting device according to the present invention is used for lifting cargo between a lower area and an upper area at a construction site, and is characterized by comprising: a base portion installed in the lower area; a support column portion erected on the base portion and positioned to extend from the lower area toward the upper area; a loading platform portion on which cargo is loaded and which is provided to be able to move up and down along the height direction of the support column portion; a drive unit that outputs power to move the loading platform portion up and down; and a power transmission unit that transmits the power of the drive unit to the loading platform portion.

[0013] With the above configuration, materials, equipment, and other items to be moved from the lower area to the upper area can be loaded onto the loading platform, and the loading platform can be moved from the lower area to the upper area using the power of the drive unit. This makes it easy to move (transport) the goods. As a result, the work of workers to directly move the goods from the lower area to the upper area is eliminated, thus reducing the workload of the workers.

[0014] (2) In the lifting device according to the present invention, preferably the loading platform is configured to allow the load to be visible from the outside when the load is loaded on it. With this configuration, the condition of the load loaded on the loading platform can be checked from the outside as appropriate. This prevents the load from falling off the loading platform, and thus ensures safety during work.

[0015] (3) In the lifting device according to the present invention, preferably the loading platform is configured to allow access to and removal of the load from the upper region. With this configuration, a worker waiting in the upper region can grasp and hold the load on the loading platform as it rises from the lower region to the upper region, or perform other tasks such as removing the load. This improves work efficiency.

[0016] (4) In the lifting device according to the present invention, preferably the loading platform is characterized in that it includes a rear portion formed to extend in the height direction of the support column and a bottom portion formed to extend away from the support column at the lower end of the rear portion. With this configuration, the load can be stably loaded onto the loading platform by loading the load in contact with both the rear portion and the bottom portion of the loading platform.

[0017] (5) In this case, preferably, the rear portion and the bottom portion are connected so as to be substantially perpendicular to each other. With this configuration, the bottom surface of the cargo can be placed against the bottom portion of the cargo bed, and the sides of the cargo can be brought into contact with the rear portion of the cargo bed and secured. This ensures the stability of the cargo relative to the cargo bed.

[0018] (6) In a configuration that includes a cargo bed including the rear portion, preferably the rear portion is formed in a rectangular shape, and the length in the height direction of the rear portion is greater than the length in the width direction. With this configuration, for example, long items can be easily loaded onto the rear portion of the cargo bed.

[0019] (7) In a configuration comprising a cargo bed including the bottom portion described above, preferably the bottom portion is formed in a rectangular shape, and the length in the width direction of the bottom portion is greater than the length in the depth direction. With this configuration, wide cargo can be easily loaded onto the bottom portion of the cargo bed.

[0020] (8) The lifting device according to the present invention is preferably characterized by being equipped with a fixing member for fixing the load loaded on the loading platform to the loading platform. With this configuration, the load can be firmly fixed to the loading platform by the fixing member. This makes it possible to prevent the load from falling off the loading platform when the loading platform is moving up and down.

[0021] (9) In the unloading apparatus according to the present invention, preferably, the driving unit is configured by a motor. With this configuration, the loading platform can be moved up and down between the lower region and the upper region using the power of the motor, so that cargo can be moved easily.

[0022] (10) In the unloading apparatus according to the present invention, preferably, the power transmission unit is configured by a chain. With this configuration, the power of the driving unit can be reliably transmitted to the loading platform, so that the loading platform can be smoothly moved up and down. Furthermore, maintainability can be improved by using a chain as the power transmission unit.

[0023] (11) In the unloading apparatus according to the present invention, preferably, the unloading apparatus comprises an operation unit for performing a driving operation or a stopping operation of the driving unit. With this configuration, the moving operation and stopping operation of the loading platform can be easily performed by operating the operation unit. For example, when it is desired to move the loading platform up or down, a driving operation may be performed on the operation unit, and when it is desired to stop the upward / downward movement of the loading platform, a stopping operation may be performed on the operation unit. In this way, the moving operation and stopping operation of the loading platform can be performed according to the judgment of an operator.

[0024] (12) In the unloading apparatus according to the present invention, preferably, a plurality of moving wheels are provided on the back surface of the base unit. With this configuration, the unloading apparatus can be easily moved to a location where cargo is easily transferred between a lower region and an upper region. Effects of the Invention

[0025] According to the aspect of the present invention, an unloading apparatus capable of reducing the labor of an operator can be provided. Brief Description of the Drawings

[0026] [Figure 1]This is an overall view of a lifting device according to one embodiment of the present invention, as seen from the right side in the width direction. [Figure 2] This is an overall view of a lifting device according to one embodiment of the present invention, as seen from the front in the depth direction. [Figure 3] This is a view from line AA in Figure 2. [Figure 4] (a) is a perspective view showing the cargo bed, and (b) is a view of the cargo bed from the front in the depth direction. [Figure 5] (a) is a view of the cargo bed from the right side in the width direction, and (b) is a view of the cargo bed from above in the height direction. [Modes for carrying out the invention]

[0027] A lifting device according to one embodiment of the present invention will be described below with reference to the attached drawings. These drawings are schematic and do not necessarily represent the sizes in exact proportions. Also, in the drawings, similar components are indicated by the same reference numerals.

[0028] The lifting device in this embodiment will be described with reference to Figures 1 to 5.

[0029] As shown in Figures 1 and 2, the lifting device 100 according to this embodiment is used for lifting materials and base materials (hereinafter sometimes collectively referred to as cargo 200) necessary for construction, loaded onto the loading platform 40 and moved between the lower floor FL (lower area) and the upper floor FU (upper area) at a construction site where a multi-story building is being constructed.

[0030] (Base) The lifting device 100 has a rectangular base portion 10 when viewed in plan. The base portion 10 is installed on the floor surface of the lower floor (FL) at the construction site. The base portion 10 is made of a material such as metal.

[0031] On the surface of the base 10 in the height direction, a control box 12, a motor 14, and a support column 16 are provided. On the underside of the base 10 in the height direction, four wheels 18 are provided for moving the lifting device 100 along the floor surface. The four wheels 18 are provided at each of the four corners of the base 10.

[0032] (Control box) The control box 12 contains an inverter, a PLC ( Programmable logic controller ), and an AVR (Automatic Voltage Regulator) are installed. The control box 12 supplies power to the motor 14 and controls the motor 14 to drive and stop in response to the operation of the foot switch 20 by the worker W, which will be described later.

[0033] (Foot switch) A foot switch 20 is electrically connected to the control box 12. The foot switch is an example of the "operation unit" of the present invention. The foot switch 20 is used to operate the motor 14. For example, the motor 14 is driven when worker W steps on the foot switch 20 with their foot, and the motor 14 is stopped when they release their foot from the foot switch 20. For example, two foot switches 20 may be provided, one located on the lower floor FL and the other on the upper floor FU. This makes it possible for each worker W waiting on the lower floor FL and the upper floor FU to operate the lifting device 100.

[0034] (motor) Motor 14 outputs power to raise and lower the cargo bed 40. Motor 14 is electrically connected to the control box 12. An output shaft 14a is provided at the end of motor 14. An output sprocket 14b is provided on the output shaft 14a. The motor 14 is configured such that the rotational drive of the output shaft 14a also drives the output sprocket 14b.

[0035] (pillar part) The support column 16 is positioned to extend from the lower floor (FL) to the upper floor (FU). The support column 16 is made of a metal material such as so-called lip channel steel. The support column 16 is set to a length that allows the loading platform 40 to move up and down between the lower floor (FL) and the upper floor (FU). In addition, four pole mounting brackets 17 are provided on the rear side of the support column 16 in the depth direction. The four pole mounting brackets 17 are arranged at equal intervals along the height direction of the support column 16. Long objects such as poles that extend along the height direction of the support column 16 are fixed to the four pole mounting brackets 17.

[0036] (Sprocket, chain) As shown in Figure 3, an input sprocket 22 and two lower sprockets 24 are positioned at the lower end of the support column 16 in the height direction. These input sprockets 22 and the two lower sprockets 24 are each pivotally supported via pillow blocks 25. A chain 28 is connected between the input sprocket 22 and the output sprocket 14b of the motor 14, and the power (rotational force) of the motor 14 is transmitted to the input sprocket 22. The power input to the input sprocket 22 is then transmitted to the two lower sprockets 24.

[0037] As shown in Figure 2, two upper sprockets 26 are positioned at the upper end of the support column 16 in the height direction. The two upper sprockets 26 are pivotally supported by each other. Two chains 30 are stretched between each of the two upper sprockets 26 and two lower sprockets 24, and as the two lower sprockets 24 rotate, the two upper sprockets 26 rotate as well. The two chains 30 also transmit power from the motor 14 to the loading platform 40, allowing the loading platform 40 to move up and down.

[0038] (Support member) As shown in Figure 1, support members 32 are positioned at predetermined height locations on the two chains 30. The support members 32 support the support column 16 so that the loading platform 40 can move up and down. The support members 32 are made of a material such as metal. In a side view, the support members 32 have a substantially L-shape.

[0039] The support member 32 includes a vertical surface portion 34 extending along the direction in which the support column portion 16 extends, and a horizontal surface portion 36 extending from the lower end of the vertical surface portion 34 toward the front in the depth direction. The vertical surface portion 34 and the horizontal surface portion 36 are connected so as to be substantially perpendicular to each other.

[0040] (Cargo bed section) The loading platform 40 is for loading cargo 200 such as materials and equipment, and is provided to be able to move up and down along the height direction of the support column 16. The loading platform 40 is fixed to the support member 32 by fastening members such as screws. The loading platform 40 is made of a material such as metal.

[0041] As shown in Figures 1, 4, and 5, the cargo bed 40 includes a rear portion 42 formed to extend in the height direction of the support column 16, and a bottom portion 44 formed at the lower end of the rear portion 42 to extend away from the support column 16 (towards the front in the depth direction). The rear portion 42 and the bottom portion 44 are connected substantially perpendicularly. The rear portion 42 and the bottom portion 44 can be formed from a single material, or from multiple materials.

[0042] The rear section 42 is formed in a rectangular shape when viewed from the depth direction. The length of the rear section 42 in the height direction is greater than the length in the width direction. As shown in Figures 4(a) and 5, a rear-side projection 46 is formed at the upper end of the rear section 42 in the height direction, projecting toward the back in the depth direction. The rear-side projection 46 can prevent accidental contact and injury to workers W waiting on the upper floor FU when the loading platform 40 rises.

[0043] The bottom portion 44 is formed in a rectangular shape when viewed from the height direction. The width of the bottom portion 44 is greater than the depth. As shown in Figures 4 and 5, a bottom-side projection 48 is formed at the front end of the bottom portion 44 in the depth direction, projecting upward in the height direction. The bottom-side projection 48 can prevent the cargo 200 from unintentionally falling off the front side in the depth direction when loading cargo 200 onto the cargo bed portion 40.

[0044] The cargo bed 40 is configured to allow the cargo 200 to be visible from the outside when it is loaded. Specifically, the cargo 200 can be seen from directions where the rear portion 42 and bottom portion 44 are not located (such as the front side in the depth direction, the width direction, and the top side in the height direction) of the cargo bed 40.

[0045] The loading platform 40 is configured to allow access to and retrieval of the cargo 200 from the upper floor FU. Specifically, since the loading platform 40 is open at the top in the height direction, when the loading platform 40 is raised from the lower floor FL to the upper floor FU, a worker W waiting on the upper floor FU can grab and retrieve the cargo 200 as it rises.

[0046] (Fixing member) As shown in Figures 1 and 2, the rear portion 42 of the cargo bed 40 is provided with fixing members 50 for securing the cargo 200 loaded on the cargo bed 40 to the cargo bed 40. Examples of fixing members 50 include chains, rubber bands, and wires.

[0047] (Method of transporting luggage) Next, with reference to Figures 1 and 2, a method for transporting cargo 200 using the lifting device 100 of this embodiment will be described.

[0048] When moving cargo 200 from the lower floor (FL) to the upper floor (FU), the loading platform 40 of the lifting device 100 is moved to its lowest position. Next, the cargo 200 is loaded onto the loading platform 40, and the cargo 200 is secured to the rear surface 42 of the loading platform 40 using fixing members 50 according to the size of the cargo 200.

[0049] Next, worker W, who is waiting on the lower floor (FL), operates the foot switch 20 to drive the motor 14. As a result, the power (rotational force) of the motor 14 is transmitted to the chain 30 attached to the support column 16, causing the chain 30 to rotate. Consequently, the loading platform 40 (support member 32) rises from the lower floor (FL) towards the upper floor (FU).

[0050] Subsequently, when the bottom surface 44 of the loading platform 40 moves to approximately the same position as the floor surface of the upper floor FU, the worker W on the lower floor FL stops operating the foot switch 20. Finally, the worker W waiting on the upper floor FU removes the cargo 200 from the loading platform 40, thereby completing the transport of the cargo 200.

[0051] When moving cargo 200 from the upper floor FU to the lower floor FL, the loading platform 40 of the lifting device 100 is moved to a position horizontal to the floor surface of the upper floor FU. Next, the cargo 200 is loaded onto the loading platform 40, and the cargo 200 is secured to the rear surface 42 of the loading platform 40 using fixing members 50 according to the size of the cargo 200.

[0052] Next, the worker W, who is waiting on the upper floor FU, operates the foot switch 20 to drive the motor 14. As a result, the power (rotational force) of the motor 14 is transmitted to the chain 30 attached to the support column 16, causing the chain 30 to rotate. Consequently, the loading platform 40 (support member 32) descends from the upper floor FU towards the lower floor FL.

[0053] Subsequently, when the bottom surface 44 of the loading platform 40 moves to approximately the same position as the floor surface of the lower floor FL, the worker W on the upper floor FU stops operating the foot switch 20. Finally, the worker W waiting on the lower floor FL removes the cargo 200 from the loading platform 40, thereby completing the transport of the cargo 200.

[0054] According to the embodiment described above, the following effects (1) to (12) can be obtained.

[0055] (1) In the lifting device 100 according to the above embodiment, a support column 16 is erected on a base 10 installed on the lower floor FL, and the support column 16 is arranged to extend from the lower floor FL towards the upper floor FU. Power from the motor 14 is transmitted to the loading platform 40 via a chain 30, allowing the loading platform 40, on which the cargo 200 is loaded, to move up and down along the height direction of the support column 16. As a result, cargo 200 such as materials and equipment to be moved from the lower floor FL to the upper floor FU can be loaded onto the loading platform 40, and the loading platform 40 can be moved from the lower floor FL to the upper floor FU using the power of the motor 14. This makes it easy to move (transport) the cargo 200. As a result, the worker W does not have to directly move the cargo 200 from the lower floor FL to the upper floor FU, thus reducing the workload of the worker W.

[0056] (2) In the lifting device 100 according to the above embodiment, the loading platform 40 is configured so that the load 200 can be seen from the outside when the load 200 is loaded. This allows the condition of the load 200 loaded on the loading platform 40 to be checked from the outside as needed. This prevents the load 200 from falling off the loading platform 40, thus ensuring safety during operation.

[0057] (3) In the lifting device 100 according to the above embodiment, the loading platform 40 is configured so that the cargo 200 can be accessed and retrieved from the upper floor FU. This allows a worker W, who is waiting in advance on the upper floor FU, to grab and hold the cargo 200 on the loading platform 40 as it rises from the lower area to the upper area, or to retrieve the cargo. Therefore, the lifting device 100 enables stable transport of cargo and improves work efficiency.

[0058] (4) In the above embodiment of the lifting device 100, a loading platform 40 is provided, which includes a rear portion 42 formed to extend in the height direction of the support column 16, and a bottom portion 44 formed at the lower end of the rear portion 42 to extend away from the support column 16. As a result, by loading the cargo 200 in contact with both the rear portion 42 and the bottom portion 44 of the loading platform 40, the cargo 200 can be stably loaded onto the loading platform 40.

[0059] (5) In the lifting device 100 according to the above embodiment, the rear portion 42 and the bottom portion 44 of the loading platform 40 are connected so as to be substantially perpendicular. This allows the bottom surface of the load 200 to be placed against the bottom portion 44 of the loading platform 40, and the sides of the load 200 to be in contact with and fixed against the rear portion 42 of the loading platform 40. This ensures the stability of the load 200 relative to the loading platform 40.

[0060] (6) In the lifting device 100 according to the above embodiment, the rear portion 42 of the loading platform 40 is formed in a rectangular shape, and the length in the height direction of the rear portion 42 is made greater than the length in the width direction. This makes it possible to easily load cargo 200 such as long items onto the rear portion 42 of the loading platform 40.

[0061] (7) In the above embodiment of the lifting device 100, the bottom surface 44 of the loading platform 40 is formed in a rectangular shape, and the length in the width direction of the bottom surface 44 is made greater than the length in the depth direction. With this configuration, wide cargo 200 can be easily loaded onto the bottom surface 44 of the loading platform 40.

[0062] (8) In the lifting device 100 according to the above embodiment, a fixing member 50 is provided for fixing the load 200 loaded on the loading platform 40 to the loading platform 40. This allows the load 200 to be firmly fixed to the loading platform 40 by the fixing member 50. This prevents the load 200 from falling off the loading platform 40 when the loading platform 40 is moving.

[0063] (9) In the lifting device 100 according to the above embodiment, the drive unit of the present invention is configured with a motor 14. As a result, the load platform 40 can be raised and lowered between the lower floor FL and the upper floor FU using the power of the motor 14, making it possible to easily move the load 200.

[0064] (10) In the lifting device 100 according to the above embodiment, the power transmission section of the present invention is configured with a chain 30. This ensures that the power from the motor 14 is reliably transmitted to the loading platform 40, allowing the loading platform 40 to move up and down smoothly. Furthermore, the use of the chain 30 improves maintainability.

[0065] (11) In the lifting device 100 according to the above embodiment, a foot switch 20 is provided for driving or stopping the motor 14. This makes it easy to move and stop the loading platform 40 by operating the foot switch 20. For example, to move the loading platform 40 up or down, the operator W should drive the foot switch 20 (by pressing the switch), and to stop the loading platform 40 from moving up or down, the operator should stop the foot switch 20 (by taking their foot off the switch). In this way, the operator W can decide whether to move or stop the loading platform 40.

[0066] (12) In the above embodiment of the lifting device 100, four wheels 18 for movement are provided on the underside of the base portion 10. This makes it possible to easily move the lifting device 100 to a location where it is easy to move the cargo 200 between the lower floor FL and the upper floor FU.

[0067] (modified version) The above embodiment can also be configured with the following modifications.

[0068] In the above embodiment, an example of using a motor as an example of a drive unit was shown, but the present invention is not limited thereto. In the present invention, it is also possible to use a drive unit other than a motor as long as it is possible to move the loading platform along the height direction of the support column.

[0069] In the above embodiment, an example of applying two chains as an example of a power transmission section was shown, but the present invention is not limited thereto. In the present invention, it is possible to apply one or three or more chains as long as it is possible to move the loading platform along the height direction of the support column. This makes it possible to configure a lifting device that can raise and lower the loading platform according to the weight of the load and the speed of movement.

[0070] In the above embodiment, an example of a cargo bed including a rear section and a bottom section was shown, but the present invention is not limited thereto. In the present invention, a cargo bed consisting only of a bottom section may be used, or a cage-type cargo bed provided with a bottom section and side sections surrounding the bottom section may be used. This makes it possible to configure a cargo bed that matches the size and shape of the cargo.

[0071] In the above embodiment, an example was shown in which the rear and bottom portions of the cargo bed are connected so as to be substantially perpendicular, but the present invention is not limited to this. For example, the angle between the rear and bottom portions of the cargo bed may be obtuse or acute. This makes it possible to configure a cargo bed that is suited to the size and shape of the cargo.

[0072] In the above embodiment, an example was shown in which a lifting device is constructed using a single support column, but the present invention is not limited to this. For example, it is also possible to construct the device by connecting multiple relatively short support columns along the height direction. This allows the support column to be divided, making it easier to transport.

[0073] The embodiments described above are all illustrative examples of the application of the present invention, and it goes without saying that any other embodiments within the scope of the claims are also included in the technical scope of the invention. [Explanation of Symbols]

[0074] 10: Base 14: Motor (drive unit) 16: Strut part 18: Wheels 20: Foot switch (control unit) 30: Chain (power transmission part) 40: Cargo bed section 42: Back part 44: Bottom part 50: Fixing member 100: Unloading equipment 200: Luggage FL: Lower floor (lower area) FU: Upper floor (upper area) W: Worker

Claims

1. It is used in construction sites for lifting cargo between lower and upper areas. A base portion installed in the lower region, A support column is erected on the base and positioned to extend from the lower region toward the upper region, A loading platform is provided on which cargo is loaded and which is capable of moving up and down along the height direction of the support column, A drive unit that outputs power to raise and lower the aforementioned cargo bed, The system includes a power transmission unit that transmits power from the drive unit to the cargo bed, The cargo bed portion includes a rear portion formed to extend in the height direction of the support column portion, and a bottom portion formed at the lower end of the rear portion to extend in a direction away from the support column portion. At the upper end of the rear portion in the height direction, a rear-side projection is formed that protrudes toward the back side in the depth direction, which is toward the support column side. The aforementioned rear protrusion is designed to prevent accidental contact and injury to workers waiting in the upper area when the cargo bed rises. The bottom portion has a bottom-side projection that protrudes upward in the height direction at the end closer to the front in the depth direction than the rear portion. A lifting device characterized in that the bottom protrusion is capable of preventing the cargo from falling off the loading platform towards the front in the depth direction.

2. The lifting device according to claim 1, characterized in that the cargo bed is configured to allow the cargo to be visible from the outside when the cargo is loaded on it.

3. The lifting device according to claim 1 or 2, characterized in that the cargo bed is configured to allow access to and removal of the cargo from the upper area.

4. The lifting device according to any one of claims 1 to 3, characterized in that the rear portion and the bottom portion are connected in a substantially perpendicular manner.

5. The aforementioned back portion is formed in a rectangular shape, The lifting device according to any one of claims 1 to 4, characterized in that the length in the height direction of the rear portion is greater than the length in the width direction.

6. The bottom portion is formed in a rectangular shape. The lifting device according to any one of claims 1 to 5, characterized in that the length in the width direction of the bottom portion is greater than the length in the depth direction.

7. A lifting device according to any one of claims 1 to 6, characterized in that it is provided with a fixing member for fixing the cargo loaded on the cargo bed to the cargo bed.

8. The lifting device according to any one of claims 1 to 7, characterized in that the drive unit is composed of a motor.

9. The lifting device according to any one of claims 1 to 8, characterized in that the power transmission section is composed of a chain.

10. The lifting device according to any one of claims 1 to 9, characterized in that it is provided with an operating unit for driving or stopping the drive unit.

11. The lifting device according to any one of claims 1 to 10, characterized in that a plurality of wheels for movement are provided on the back surface of the base portion.

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