Board lifting device

Abstract

This invention provides a board lifting device that utilizes an already installed manual lifting structure, and by integrating an electric lifting structure into the manual lifting structure, it is possible to make full use of the functions of the manual lifting structure. [Solution] A box body 3, on which a board 2 is mounted so as to be able to move up and down, is fixed to the wall. A balance mechanism 10 is provided inside the box body 3, in which a drum 12 that rotates in accordance with the up and down movement of the board 2 and a spring 14 that expands and contracts in accordance with the up and down movement of the board 2 are connected by a wire 15. An electric lifting device 4 that expands and contracts by motor drive to move the board 2 up and down is installed on the floor surface 6 with the board 2 supported. The electric lifting device 4 expands and contracts while the weight of the board 2 is absorbed by the balance mechanism 10.

Description

Technical Field

[0001] The present invention relates to a board lifting device for lifting and lowering boards such as blackboards installed in school classrooms, training rooms and the like.

Background Art

[0002] Various boards such as blackboards, whiteboards, screens, and electronic boards are required to have adjustable height in order to efficiently perform writing functions and display functions. For this reason, the board can be lifted and lowered relative to the wall surface. As mechanisms for lifting and lowering the board, there are manual structures operated manually by an operator and electric structures driven by a motor. Conventional techniques for manual lifting structures are disclosed in Patent Documents 1 to 3, and conventional techniques for electric lifting structures are disclosed in Patent Documents 4 to 7.

Prior Art Literature

Patent Literature

[0003]

Patent Literature 1

Patent Literature 2

Patent Literature 3

Patent Literature 4

Patent Literature 5

Patent Literature 6

Patent Literature 7

Summary of the Invention

Problems to be Solved by the Invention

[0004] Manual lifting mechanisms can be simple in design, but they are heavy and difficult to operate for women and children. On the other hand, electric lifting mechanisms are easy to operate, but require the installation of a complex electric mechanism. Therefore, both have their advantages and disadvantages. For these reasons, conventional lifting mechanisms have been either manual or electric.

[0005] In the case of blackboards, manual raising and lowering is the primary method due to the need for easy operation within the classroom. Converting these manually operated boards to an electrically operated system would require replacing the entire system, including the existing manual structure and board, with an electric system, necessitating extensive construction work, considerable labor, and materials. Furthermore, since the manual structure and board would need to be removed from the building's wall, wall modifications are also essential.

[0006] This invention was made in consideration of these problems, and aims to provide a board lifting device that utilizes the functions of a manual lifting structure already installed in classrooms, lecture halls, etc., by incorporating an electric lifting structure into this manual lifting structure. [Means for solving the problem]

[0007] A box body to which a board is mounted so as to be able to move up and down is fixed to a wall surface, a balance mechanism is provided inside the box body in which a drum that rotates in accordance with the up and down movement of the board and a spring that expands and contracts in accordance with the up and down movement of the board are connected by a wire, an electric lifting device that expands and contracts by motor drive to move the board up and down is installed on the floor surface with the board in a position to support the board, and the electric lifting device expands and contracts while the weight of the board is absorbed by the balance mechanism.

[0008] The present invention is characterized in that a sub-board is slidably mounted on the front surface of the main board. Furthermore, the range of vertical movement of the electric lifting device is limited to the range of vertical movement of the board when the weight of the board is absorbed by the balance mechanism. Furthermore, the electric lifting device is characterized by comprising a support column to which the board is attached at the upper end and which is extendable and retractable in the vertical direction, a motor provided inside the support column, and a gear mechanism provided inside the support column that converts the rotation of the motor into extension and retraction of the support column. Furthermore, the board is characterized by being a blackboard or whiteboard installed in a classroom. [Effects of the Invention]

[0009] According to the present invention, an existing manual box structure is utilized, and an electric lifting device is assembled to this box structure, allowing the use of a known conventional structure as the box structure. Therefore, the construction of a new box structure is unnecessary, eliminating the need for construction work and removal work of the existing box structure, thus saving labor and materials. Furthermore, since there is no need to remove the existing box structure, no work on the wall surface is required. [Brief explanation of the drawing]

[0010] [Figure 1] This is a front view of a board lifting device according to one embodiment of the present invention. [Figure 2] This is a side view of the board lifting device. [Figure 3] This is a front view showing a schematic of the box-shaped body. [Figure 4] (A) and (B) are cross-sectional views showing the inside of the electric lifting device in operation. [Figure 5] This is a cross-sectional view showing another embodiment of the present invention. [Modes for carrying out the invention]

[0011] Hereinafter, the board lifting device of the present invention will be described with reference to the illustrated embodiments. FIG. 1 is a front view of an embodiment, FIG. 2 is a side view, FIG. 3 is a front view of the interior of the box body, and FIG. 4 is a sectional view of the interior of the electric lifting device.

[0012] As shown in FIG. 1 and FIG. 2, the board lifting device 1 includes a board 2 typified by a blackboard, a whiteboard, a screen, etc., a box body 3, and an electric lifting device 4. The board 2 is attached to the box body 3, the box body 3 is fixed to a wall surface 5 of a building, and the electric lifting device 4 is installed on a floor surface 6 of the building.

[0013] The board 2 is formed of a horizontally long rectangular board body 2a and a support frame 7 that supports the board body 2a. The support frame 7 is formed of upper and lower support rods 7b, and left and right guide rods 7a that connect the left and right ends of the upper and lower support rods 7b (see FIG. 2 and FIG. 3). The left and right guide rods 7a penetrate the box body 3 so as to be movable up and down, and the entire board 2 moves up and down on the front side of the box body 3 by the vertical movement of the guide rods 7a.

[0014] The box body 3 is fixed to the wall surface 5 of the building by anchor bolts 11. Inside the box body 3, a balance mechanism 10 capable of moving the board 2 up and down is provided. As shown in FIG. 3, the balance mechanism 10 includes a rotatable drum 12, a telescopic spring 14, left and right pulleys 16, 17, and a wire 15 connecting these components. The left and right pulleys 16, 17 are connected to the lower support rod 7b of the board 2 by the wire 15.

[0015] In the balance mechanism 10, when the board 2 moves up and down, the drum 12 rotates in forward and reverse directions to expand and contract the spring 14. The spring 14 expands and contracts corresponding to the vertical movement of the board 2. Since the expansion and contraction of the spring 14 absorbs the weight of the entire board 2, the vertical movement of the board 2 can be performed with a small force. That is, the balance mechanism 10 is in a state of absorbing the weight of the board 2 because the drum 12 is rotatable.

[0016] As the above-described balance mechanism 10, conventional structures disclosed in Japanese Unexamined Patent Publication No. 2013-10356, Japanese Unexamined Patent Publication No. 11-137362, Japanese Unexamined Patent Publication No. 2001-61580 and the like can be used. In these conventional structures, similarly to the present invention, a box body having a structure in which a brake handle is added to a balance mechanism is fixed to a wall surface, and is configured to lock and unlock the rotation of the drum 12 by the brake handle. In contrast, the present invention uses the balance mechanism 10 having a structure that is not provided with this brake handle. Therefore, the drum 12 is always rotatable, and is constantly in a state of absorbing the weight of the board 2. This allows the board 2 to always be movable up and down.

[0017] From the above, as the box body 3 provided with the balance mechanism 10 of the present invention, an existing conventional box body that is provided with a balance mechanism and fixed to a wall surface can be used as-is, and the box body can be used simply by removing the brake handle from this conventional box body. As described above, since the existing box body can be used in the present invention, there is an advantage that replacement with a new box body is not required, and replacement work of the box body and work on the wall surface 5 are not required.

[0018] FIG. 4 shows the electric lifting device 4, where (A) shows a state where the board 2 is lowered, and (B) shows a state where the board 2 is raised. The electric lifting device 4 is installed on a floor surface 6 in a state of supporting the board 2, and expands and contracts by motor drive in this installed state to move the board 2 up and down. When the electric lifting device 4 is assembled, the box body 3 is in an existing state fixed to the wall surface 5.

[0019] A plurality (two or more) of the electric lifting devices 4 are provided spaced apart from each other. The electric lifting device 4 is installed on the floor surface 6 and has a support column 20 that supports the lower surface of the board 2 (in the illustrated example, the lower support rod 7b (see FIGS. 2 and 3)). The support column 20 is formed of an upper stage 20a, a middle stage 20b, and a lower stage 20c, and is extendable and contractible. The upper stage 20a is connected to the lower surface of the board 2 by an L-shaped metal fitting. An electric actuator 21 is disposed inside the lower stage 20c of the support column 20.

[0020] The electric actuator 21 includes a motor 22 that rotates using DC power, and a gear mechanism 23 that reduces the rotation of the motor 22 and converts it into extension and retraction of the support column 20. The gear mechanism 23 includes a reduction gear 24, a ball screw 25, a lifting table 26 attached to the ball screw 25, a lifting shaft 27 connected to the lifting table 26 for raising and lowering the upper section 20a of the support column 20, and a guide 28 for guiding the lifting table 26 in the vertical direction.

[0021] In the electric lifting device 4, when the motor 22 is rotated forward, the ball screw 25 rotates via the reduction gear 24, causing the lifting table 26 to rise and the lifting shaft 27 to push up the upper section 20a of the support column 20. When the motor 22 is rotated in the reverse direction, the ball screw 25 rotates in the reverse direction via the reduction gear 24, causing the lifting table 26 to descend and the lifting shaft 27 to pull down the upper section 20a of the support column 20. As a result, the support column 20 extends and retracts, causing the board 2 to move up and down.

[0022] An operating switch 29 is provided to control the forward and reverse rotation of the motor 22. The operating switch 29 is attached to the lower support rod 7b of the board 2 (Figures 1 and 2). The operating switch 29 is a momentary switch; when pressed upwards, an up signal is output for upward movement, and when released, the signal stops in the neutral state. When pressed downwards, a down signal is output for downward movement, and when released, it returns to the neutral state. The motor 22 rotates while the up signal and down signal are output.

[0023] In this embodiment, the weight of the board 2 is absorbed by the balance mechanism 10, specifically, the drum 12 of the balance mechanism 10 is made rotatable, allowing the board 2 to move up and down. As a result, the electric lifting device 4 can be extended and retracted, and the board 2 can be raised and lowered by the electric lifting device 4.

[0024] In this embodiment, since the box body 3, which has a balance mechanism 10 inside, is already installed on the wall surface 5, and the electric lifting device that moves the board 2 up and down is installed on the floor surface 6, a known conventional structure can be used as the box body 3. Therefore, the installation of a new box body 3 is unnecessary, and the construction work for that, as well as the removal work of the existing box body, is unnecessary, saving labor and materials. In addition, since there is no need to remove the existing box body, no construction work on the wall surface 5 is necessary.

[0025] In one embodiment of the present invention, a conventional box structure fixed to a wall can be used without modification. In the conventional box structure, the balance mechanism is equipped with a brake handle for locking and unlocking the drum. In this embodiment, the brake handle is used to hold the drum's rotation in the unlocked state without removing it. As a result, the balance mechanism continues to absorb the weight of the board, allowing the board to be raised and lowered by an electric lifting device. Therefore, in this embodiment, no processing of the balance mechanism is required, and the conventional balance mechanism can be used as is, which is an advantage.

[0026] In this embodiment, it is preferable that the range of extension and retraction of the electric lifting device 4 is limited to the range of vertical movement of the board 2 when the weight of the board 2 is absorbed by the balance mechanism 10. In other words, when the balance mechanism 10 absorbs the weight of the board 2, the spring 14 expands and contracts, allowing the board 2 to move up and down. However, when the balance mechanism 10 does not absorb the weight of the board 2, the spring 14 does not expand or contract (cannot expand or contract), making it impossible to move the board 2 up and down. Since it is necessary to suppress the expansion and contraction of the electric lifting device 4 (i.e., the up and down movement of the board 2 in an overloaded state) in such an overloaded state, the lifting range of the electric lifting device 4 is restricted.

[0027] To limit the range of extension and retraction of the electric lifting device 4, a distance sensor 35 is provided, as shown in Figure 4. In this configuration, the distance sensor 35 is attached to the vertically moving lifting table 26 and measures the distance between it and the reduction gear 24 (i.e., the amount of extension and retraction of the support column 20). The measured value is transmitted to a controller (not shown) to measure the amount of extension and retraction of the support column 20 (i.e., the amount of extension and retraction of the electric lifting device 4) and compare it with a reference value set in the controller. If the amount of extension and retraction deviates from the reference value, the above-mentioned overload condition occurs, and the controller stops driving the motor 22. This limits the range of extension and retraction of the electric lifting device 4 to the range of vertical movement of the board 2 when the weight of the board 2 is absorbed by the balance mechanism 10.

[0028] Figure 5 shows a board lifting device 1A of another embodiment of the present invention. In this board lifting device 1A, a sub-board 31 is attached to the front of the board 2, so that the sub-board 31 is added to the board 2. The sub-board 31 can use a monitor display, which allows it to display information other than the information on the board 2.

[0029] The sub-board 31 is slidably mounted on the front of the board 2. To enable the sub-board 31 to slide, a sliding member 32, assembled in a grid pattern, is slidably provided on the front of the board 2, and the sub-board 31 is attached to this sliding member 32. In addition, a guide rail 33 extending in the longitudinal direction of the board 2 is attached to the upper and lower positions on the front of the board 2. As the sliding member 32 slides along the guide rail 33, the sub-board 31 slides along the front side of the board 2. In the solid line state shown in Figure 5, the sub-board 31 is in use, having slid to the center of the board 2. In the dashed line state, the sub-board 31 is retracted to the right edge of the board 2, and in this retracted state, almost the entire surface of the board 2 can be used.

[0030] In the embodiment shown in Figure 5, as in Figures 1 and 2, a box body 3 with a balance mechanism 10 (see Figure 3) inside is fixed to the wall surface 5 (see Figure 2), and a board 2 is attached to this box body 3 so as to be able to move up and down. In this embodiment as well, an electric lifting device 4 for moving the board 2 up and down is provided on the floor surface 6. The electric lifting device 4 uses the same structure as in Figures 1 and 4, and extends and retracts by motor drive to move the board 2 up and down. At this time, the sub-board 31 moves up and down together with the board 2.

[0031] In the configuration where the sub-board 31 is attached to the board 2, the weight increases due to the addition of the sub-board 31. Therefore, the balance mechanism 10, which is only designed to handle the weight of the board 2, becomes overloaded, preventing the board 2 from being raised or lowered. In this embodiment, since the power of the electric lifting device 4 is used to raise and lower the board 2, the board 2 with the sub-board 31 attached can be raised and lowered reliably and smoothly. [Explanation of Symbols]

[0032] 1 1A Board Lifting Device 2 boards 3 Box Body 4. Electric lifting device 5 Wall surface 6 Floor surface 7 Support Frame 7a Guide Rod 7b Support rod 10. Balance mechanism 11 Anchor bolts 12 drums 13 Handle 14 Springs 15 wires 16 17 Pulley 20 Support pillar 21 Electric Actuator 22 motors 23 Gear mechanism 24 reduction gear 25 Ball screw 26 Height-adjustable tables 27 Lifting shaft 28 Guide 29 Operation switches 31 Subboard 32 Sliding member 33 Guide rails 35 Distance Sensor

Claims

1. A box-shaped structure with a board that can move up and down is fixed to the wall. A balance mechanism is provided inside the box body, in which a drum that rotates in accordance with the vertical movement of the board and a spring that expands and contracts in accordance with the vertical movement of the board are connected by a wire. An electric lifting device that extends and retracts by motor drive to move the board up and down is installed on the floor surface with the board in a position that supports the board. The electric lifting device is characterized in that it extends and retracts while the weight of the board is absorbed by the balance mechanism.

2. The board lifting device according to claim 1, characterized in that a sub-board is slidably mounted on the front surface of the aforementioned board.

3. The board lifting device according to claim 1, characterized in that the range of extension and retraction of the electric lifting device is limited to the range of vertical movement of the board when the weight of the board is absorbed by the balance mechanism.

4. The electric lifting device is characterized by comprising a support column to which the board is attached at the upper end and which is extendable and retractable in the vertical direction, a motor provided inside the support column, and a gear mechanism provided inside the support column that converts the rotation of the motor into extension and retraction of the support column.

5. The board lifting device according to claim 1 or 2, characterized in that the board is a blackboard or whiteboard installed in a classroom.

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