JPH11253258A - Device for elevating and lowering blackboard - Google Patents

Abstract

PROBLEM TO BE SOLVED: To elevate and lower a blackboard without bearing a portion of its load. SOLUTION: A device for elevating and lowering a blackboard is constituted of a fixed frame 2 to be fixed to a wall surface, an elevating and lowering frame 3 which can be vertically elevated and lowered with respect to the fixed frame 2, a lift cylinder device 4 disposed between the fixed frame 2 and the elevating and lowering frame 3, an electrohydraulic unit 5 capable of supplying pressure oil for the lift cylinder 43 of the lift cylinder device 4, a remote-control device 6 provided with a switch to turn the electric motor 51 of the electrohydraulic unit 5 normally or reversely. The remote-control device 6 is freely attached and detached via a connector C. The lift cylinder 43 is slide- freely fitted into outer tube 41 and 41 fixed to the fixed frame 2, and the periphery of the lift cylinder 43 is covered with an inner cylinder 42 fixed to the elevating and lowering frame 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a blackboard elevating device.

[0002]

2. Description of the Related Art Generally, a blackboard is fixed to a wall of a classroom,
The teacher writes the contents of the lesson. In the blackboard fixed to the wall in this way, there is a problem that it is difficult for a rearward student to see a sign or the like held on the blackboard by characters or magnets written on the blackboard due to the sitting height of the front student. For this reason, an ascending and descending blackboard that can be moved up and down as needed is known.

[0003] Although this elevating blackboard is not shown in detail,
Winding means having a fixed frame fixed to a wall surface, an elevating frame slidably fitted in the fixed frame, and a wire wound between the fixed frame and the elevating frame and having a spring interposed at one end. And supports the weight of the blackboard using the tension of the spring. Then, the blackboard can be stopped at an appropriate height by lifting or lowering the blackboard while holding down the brake handle provided on the elevating frame and releasing the hand from the brake handle.

[0004]

In the above-described lifting blackboard using a spring, the tension of the spring is adjusted via an adjustment chain provided on the side surface of the fixed frame in accordance with the weight of the blackboard which varies depending on the manufacturer. However, this adjustment work must be performed by putting a hand in a narrow space between the back surface of the blackboard and the wall surface, and the work is extremely difficult. The spring force can be adjusted within a certain range where the spring can be pulled, but the teacher needs to support the weight of the blackboard beyond the adjustment range. For example, a blackboard is large and weighs about 200 kgf, and about 30 kgf is a weight that the spring cannot support. Therefore, in order to lift the blackboard, it is necessary for the teacher to supplement and support about 30 kgf, which exceeds the adjustment range of the spring. This weight places a heavy burden on women, and given the remarkable advance of women into the teaching profession, there is difficulty in operation with the above-described spring-based blackboard that uses springs.

When the blackboard is moved up and down, the biasing force of the spring acts on the blackboard, causing the blackboard to move up and down at an accelerated rate, and the magnet or chalk attracted to the blackboard may fall off due to the inertia force at the time of moving up and down. is there. Furthermore, since the child can easily go up and down due to mischief or the like during a break time, there is a disadvantage that the frequency of use increases and a failure easily occurs.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a blackboard elevating device which can easily raise and lower a blackboard regardless of gender.

[0007]

According to the present invention, there is provided a fixed frame fixed to a wall surface via an anchor bolt and having guides fixed to both left and right ends, and slidably fitted to the guides of the fixed frame. The slide pipe is fixed to both left and right ends, and a lifting frame capable of fixing a blackboard, a lift cylinder device provided with a lift cylinder disposed between the fixed frame and the lifting frame, An electric hydraulic unit capable of supplying pressure oil to the cylinder, and a remote control device provided with a switch for rotating the electric motor of the electric hydraulic unit forward or reverse, the remote control device is detachable via a connector. The lift cylinder of the lift cylinder device is slidably fitted to the outer cylinder fixed to the fixed frame and the outer cylinder. Around the inner cylinder fixed to the lifting frame is characterized in that it is coated.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show a blackboard elevating / lowering device 1 of the present invention. The lifting device 1 is provided with a fixed frame 2 that can be fixed to the wall of a classroom, a lifting frame 3 that is slidably inserted into the fixed frame 2 in a vertical direction, and a fixed frame 2 and the lifting frame 3. A lift cylinder device 4, an electric hydraulic unit 5 for supplying pressure oil to a lift cylinder 43 of the lift cylinder device 4, a remote control device 6 for controlling a rotation direction of an electric motor 51 of the electric hydraulic unit 5, It is composed of

The fixed frame 2 has an upper frame 21 and a lower frame 22 having a U-shaped cross section, and a side frame having a flange fixed to both left and right edges of the upper frame 21 and the lower frame 22 by welding or the like. 23
And upper frame 21 and lower frame 2
2 is arranged so that the arm pieces are opposed to each other,
A reinforcing frame 24 is fixed between the arm pieces of the upper frame 21 and the arm pieces of the lower frame 22 at appropriate intervals. And the fixed frame 2 is the side frame 2
The anchor bolt can be fixed to the wall surface by driving an anchor bolt through a bolt hole 23a formed in the rear flange of No. 3. Also, the upper frame 2 of the fixed frame 2
A guide (nylon bush) 25 for guiding a slide pipe 33 of the elevating frame 3, which will be described later, is fixed near the left and right ends of the lower frame 1 and the lower frame 22.

On the other hand, the lifting frame 3 comprises an upper frame 31 and a lower frame 32 having a C-shaped cross section, and slide pipes 33 fixed to both left and right ends of the upper frame 31 and the lower frame 32. The upper frame 31 and the lower frame 32 are arranged so that the arm pieces are opposed to each other.
Are guides 25 attached to the upper frame 21 and the lower frame 22, respectively, of the fixed frame 2 described above.
Is slidably fitted in And the lifting frame 3
On the upper frame 31 and the lower frame 32, mounting brackets 34 for holding the blackboard B (see FIG. 2) from above and below are fixed at appropriate intervals.

The lift cylinder device 4 has an outer cylinder 41 fixed to the center of the fixed frame 2 in the left-right direction, and is slidably fitted to the outer cylinder 41, and has an upper end mounted on the upper frame 31 of the lifting frame 3. A fixed inner cylinder 42, a lift cylinder (single-acting cylinder) 43 housed in the outer cylinder 41 and the inner cylinder 42, and having a cylinder barrel fixed to the outer cylinder 41 and a piston rod fixed to the inner cylinder 42, respectively. , Is composed of. For this reason, by supplying the pressurized oil to the lift cylinder 43, the piston rod extends, and the outer cylinder 4
The inner cylinder 42, that is, the lifting frame 3 can be raised with respect to 1. The blackboard B and the lifting frame 3
When the piston rod is reduced by its own weight, the elevating frame 3 descends, and at this time, the inner cylinder 42 is housed in the outer cylinder 41.

Further, as shown in detail in FIG. 4, the electric hydraulic unit 5 includes an electric motor 51 and the electric motor 5.
A screw shaft 52 having one end connected to one output shaft 51a and the other end pivotally supported via a bearing J, a pair of cylinders 53 arranged so as to sandwich the screw shaft 52 from both sides, and a female screw. The connecting members 5 formed and screwed to the screw shaft 52, and connected to the piston rod tips of the cylinders 53, respectively.
By rotating the electric motor 51 in the normal and reverse directions, the screw shaft 52 also rotates in the same direction, so that the connecting member 54 connected to the piston rod of the cylinder 53 moves along the screw shaft 52. 4 in the left-right direction of FIG. When the connecting member 54 advances and retreats, the piston rod of the cylinder 53 connected to the connecting member 54 expands and contracts, and supplies the pressurized oil in the cylinder barrel to the lift cylinder 43 or the pressurized oil in the lift cylinder 43. Can be recovered. The screw shaft 5 of the electric hydraulic unit 5
2. The pair of cylinders 53 and the connecting member 54 are disposed in a storage frame 55 (see FIG. 1) having a C-shaped cross section disposed between the pair of reinforcing frames 24 adjacent to the fixed frame 2.

Although not shown in detail, the storage frame 55 is electrically connected to the elevating frame 3, ie, the forward limit position and the retreat limit position of the connecting member 54 corresponding to the ascending and descending limit positions of the blackboard B. Contacts, for example
A limit switch is provided, and when the connecting member 54 reaches a forward limit position or a backward limit position, a dog provided on the connecting member 54 switches an electric contact and stops the rotation of the electric motor 51. For this reason, it is possible to prevent the lift cylinder 43 from being extended beyond the ascending limit position due to the continued supply of the pressure oil to the lift cylinder 43 and damaging the elevating frame 3 and the like.

On the other hand, the remote control device 6 includes an ascending switch 6a and a descending switch 6b for rotating the electric motor 51 forward and reverse to move the elevating frame 3 up and down. Electric motor 51
A connector (male) C1 that is directly connectable to a connector (female) C provided on the fixed frame 2, the elevating frame 3, or the blackboard B is provided. Therefore, when the remote control device 6 is unnecessary, the connector C1 of the remote control device 6 can be pulled out from the connector C and stored outside the classroom, so that children are not allowed to raise and lower the blackboard B due to mischief. ing.

The upper frame 21 of the fixed frame 2
On the upper surface of the left and right ends, a nylon upper stopper 7 loosely fitted to the slide pipe 33 is provided, and on the upper surface of the left and right ends of the lower frame 32 of the elevating frame 3, the slide stopper 33 is loosely fitted. Nylon lower stopper 71
Is provided. Therefore, when the lifting frame 3 moves up and reaches the ascending limit position, its lower frame 32
Abuts on the lower frame 22 of the fixed frame 2 via the lower stopper 71, and when the elevating frame 3 descends and reaches the lower limit position, the upper frame 31 is moved to the upper part of the fixed frame 2 via the upper stopper 7. Frame 21
And the blackboard B immediately stops at the contact position. At this time, as described above, the dog of the connecting member 54 comes into contact with an electric contact (not shown) to switch the electric contact.

When the lifting device 1 for the blackboard B is constructed, an anchor bolt is driven into a wall through a bolt hole 23a formed in a rear flange of the side frame 23 of the fixed frame 2 and fixed. Then, the blackboard B carried into the classroom may be sandwiched and fixed via attachment members 34 fixed to the upper frame 31 and the lower frame 32 of the elevating frame 3, respectively. The electric motor 5
The plug connected to 1 is plugged into a classroom outlet.

When the blackboard B is lifted, the connector C1 of the remote control device 6 is connected to the blackboard B or the lifting device 1
Connected to the connector C attached to the
When a is pressed, the electric motor 51 starts normal rotation.
In this case, the screw shaft 52 connected to the output shaft 51a of the electric motor 51 also rotates forward, and the connecting member 54 screwed to the screw shaft 52 is advanced leftward in FIG. As a result, the connecting member 54 pushes the piston rod of the cylinder 53 and supplies the pressurized oil to the lift cylinder 43 to extend it. In this case, the cylinder 53 functions as a hydraulic pump. Lift cylinder 4
When the extension 3 is extended, the elevating frame 3 is elevated with respect to the fixed frame 2, and eventually the blackboard B is elevated. Here, if the pressing operation of the raising switch 6a is stopped, the electric motor 51,
That is, since the rotation of the screw shaft 52 is stopped, the connecting member 54 does not move, the supply of the pressurized oil is stopped, and the lift cylinder 4, that is, the blackboard B is stopped at a position in the middle of its upward movement.

When the ascent switch 6a is continuously depressed and the connecting member 54 reaches the forward limit position, the dog of the connecting member 54 switches the electrical contact and stops the rotation of the electric motor 51. B stops at the ascending limit position. In this case, the lifting frame 3 is
1 and is in contact with the fixed frame 2.

On the other hand, when lowering the blackboard B, when the lowering switch 6b of the remote controller 6 is pressed, the electric motor 51 starts reverse rotation, and the screw shaft 52 connected to the output shaft 51a also reverses. Then, the connecting member 54 screwed to the screw shaft 52 is retracted rightward in FIG. As a result, the connecting member 54 pulls the piston rod of the cylinder 53 and allows the lift cylinder 43 to be reduced by the weight of the blackboard B and the lifting frame 3. In this case, the cylinder 53 is
It functions as an oil reservoir that stores return oil from the tank. When the lift cylinder 43 is reduced, the lifting frame 3
Descends with respect to the fixed frame 2, and eventually the blackboard B descends. Here, if the pressing operation of the down switch 6b is stopped, the electric motor 51, that is, the screw shaft 5
Since the rotation of No. 2 is stopped, the connecting member 54 does not move, the return of the pressure oil is prevented, and the lift cylinder 4, that is, the blackboard B, is stopped at a position on its way down.

When the lowering switch 6b is continuously pressed and the connecting member 54 reaches the retreat limit position, the dog of the connecting member 54 switches the electric contact and stops the rotation of the electric motor 51. B stops at the lower limit position. In this case, the lifting frame 3 is in contact with the fixed frame 2 via the upper stopper 7.

As a result, the switch 6 of the remote control device 6
The blackboard B can be raised or lowered only by operating the buttons a and 6b, and the blackboard B can be raised and lowered without partially sharing the weight of the blackboard B regardless of gender. Also,
Since the blackboard B rises and falls quietly at a constant speed, no inertial force acts on the blackboard B, and the magnets, chalks, and the like adsorbed on the blackboard B do not fall off and do not hinder the class. Further, since the periphery of the lift cylinder 43 is covered by the outer cylinder 41 and the inner cylinder 42, chalk powder does not adhere to the lift cylinder 43 and does not hinder the expansion / contraction operation. Further, since the remote control device 6 can be pulled out from the connector C and stored outside the classroom when not in use,
The child does not raise or lower the blackboard due to mischief or the like, and the structure is simple, so that a failure can be prevented for a long time.

[0023]

As described above, according to the present invention, a fixed frame fixed to a wall surface via an anchor bolt and having guides fixed to both left and right ends, and slidably fitted to the guides of the fixed frame. The inserted slide pipe is fixed to both left and right ends, and a lifting frame capable of fixing a blackboard, a lift cylinder device provided with a lift cylinder disposed between the fixed frame and the lifting frame, and mounted on the fixed frame. An electric hydraulic unit capable of supplying pressure oil to the lift cylinder, and a remote control device having a switch for rotating the electric motor of the electric hydraulic unit forward or reverse, and the remote control device is detachable via a connector. The lift cylinder of the lift cylinder device is an outer cylinder fixed to a fixed frame and slidably fitted to the outer cylinder. In addition, since the surrounding area is covered by the inner cylinder fixed to the elevating frame, regardless of gender, the blackboard can be easily raised and lowered, and chalk powder adheres to the lift cylinder to prevent expansion and contraction operation. In addition, the failure can be prevented for a long time, and the remote control device is pulled out of the connector and stored outside the classroom, so that the child does not move up and down the blackboard due to mischief. Further, since the blackboard rises and lowers quietly at a constant speed, chalk and the like do not fall off and do not hinder the class.

[Brief description of the drawings]

FIG. 1 is a front view showing a blackboard elevating device according to the present invention.

FIG. 2 is a side view of the blackboard elevating device of FIG. 1;

FIG. 3 is a perspective view showing a blackboard elevating device of the present invention with a part thereof omitted;

FIG. 4 is a plan view illustrating an electric hydraulic unit constituting the blackboard elevating device of the present invention.

FIG. 5 is an explanatory diagram showing a relationship between an electric hydraulic unit and a remote control device which constitute the blackboard elevating device of the present invention.

[Explanation of symbols]

 Reference Signs List 1 lifting device 2 fixed frame 21 upper frame 22 lower frame 23 side frame 25 guide 3 lifting frame 31 upper frame 32 lower frame 33 slide pipe 4 lift cylinder device 41 outer cylinder 42 inner cylinder 43 lift cylinder 5 electric hydraulic unit 51 electric motor 52 screw shaft 53 cylinder 54 connecting member 6 remote control device 6a, 6b switch C, C1 connector

Claims (1)

[Claims] 1. A fixed frame fixed to a wall surface via anchor bolts and having guides fixed to both left and right ends, and a slide pipe slidably fitted to the guide of the fixed frame is provided at both left and right ends. An elevating frame that is fixed and that can fix the blackboard, a lift cylinder device that is provided between the stationary frame and the elevating frame, and that is equipped with a lift cylinder, and that is installed on the stationary frame and can supply pressure oil to the lift cylinder An electric hydraulic unit, and a remote control device having a switch for rotating the electric motor of the electric hydraulic unit forward or reverse, the remote control device being detachable via a connector, and The lift cylinder was slidably fitted into the outer cylinder fixed to the fixed frame and the outer cylinder, and was fixed to the lifting frame. An elevating / lowering device for a blackboard, the periphery of which is covered by an inner cylinder.