JP5976394B2 - Lifting scaffolding device - Google Patents

Description

  The present invention relates to a lifting and lowering scaffold device that can be used for a temporary scaffolding laid in, for example, a building such as a building, and in particular, a work floor can be moved up and down.

  Conventionally, a temporary scaffold is provided along a building in, for example, a building such as a building, and has a work floor for an operator to perform work. In recent years, an elevating type scaffolding device in which a work floor can be moved up and down in the vertical direction has been proposed (see, for example, Patent Document 1).

Japanese Patent No. 2881677

  Among the above-mentioned lifting-type scaffolding devices, for example, there are two towers, and a scaffolding part having a work floor is connected between these towers, and this scaffolding part moves up and down while maintaining a horizontal state. ing. That is, this lifting type scaffolding device includes, for example, two towers arranged side by side at a predetermined interval on the ground where the building is erected, and each has a lifting unit that can be moved up and down along each tower. It has been. And the scaffold part is connected between both raising / lowering parts.

  Each lifting part is lifted and lowered, for example, by rotationally driving a motor, and each lifting part is lifted and lowered at the same timing, so that the scaffold part is raised and lowered while maintaining almost horizontal. Then, when the scaffold portion is raised to a predetermined height position and stopped, the worker who is on the scaffold portion can perform the height work as it is at the predetermined height position.

  In the lifting / lowering scaffold device, a power supply voltage (for example, AC 200V) is supplied to a motor for moving the scaffolding portion up and down. In this lifting and lowering scaffold device, a power supply cable for supplying a power supply voltage to the motor is laid in a so-called basket system. That is, the power supply cable is housed in a basket provided on the ground, for example, in a state of being wrapped around a tuna, and one end thereof rises from the basket and is connected to the control panel via the air. Then, a power cable is separately laid from the control panel to the motor provided in the elevating unit, whereby a power supply voltage is supplied. Therefore, the power supply cable stored in the basket is pulled out of the basket when the lifting unit is raised, and is dropped into the basket by its own weight when the lifting unit is lowered.

  However, the power supply cable, for example, comes into contact with the upper end of the basket when the scaffolding portion is raised, or is caught by the wind or the like and hooked with the casing portion of the lifting and lowering scaffolding device. Therefore, tension is applied to the power supply cable, and the power supply cable may be disconnected. For example, a cabtyre cable is used as the power supply cable, so that the longer the length of the power supply cable, the greater the weight of the entire cable. Therefore, if the power supply cable is disconnected, the power supply cable falls due to its own weight, which may be dangerous for an operator on the ground.

  Further, for example, if the scaffold part rises to a predetermined height and the power supply cable is disconnected at that time, the power supply voltage is not supplied to the motor. Since the motor is normally provided with a brake braking function that automatically stops its rotation when the power supply voltage is not supplied, the scaffolding portion remains stopped at the height position. Therefore, the scaffold portion cannot be lowered by driving the motor, and there is a problem that it becomes difficult for an operator who has been on the scaffold portion to get down to the ground.

  The present invention has been conceived under the circumstances described above, and provides an elevating type scaffolding device capable of preventing problems such as disconnection of a power supply cable at the time of elevating operation of the scaffolding part. This is the issue.

The lifting and lowering scaffold device provided by the present invention includes a tower portion extending in the vertical direction, a lifting and lowering portion provided so as to be movable up and down along the tower portion, and a lifting and lowering portion provided in the lifting and lowering portion. Driving means for applying the driving force, a scaffold provided in a lateral direction of the elevating unit and moving up and down as the elevating unit moves up and down, an encoder for detecting a height position of the scaffold unit, A power supply cable for supplying a power supply voltage for driving the driving means from a ground facility provided on the ground, and a detection for detecting that a tension is applied to the power supply cable during the lifting / lowering operation of the scaffold unit and means, when that tension is applied is detected relative to the power supply cable by the detecting means, and control means for prohibiting the driving of said driving means, said detecting means, A long movable part supported so as to allow seesaw operation to the scaffolding part, a support part provided on one end side of the movable part for guiding and supporting a part of the power supply cable, and the other end of the movable part A contact plate supported on the side, and supported by the scaffold portion at a predetermined interval from the contact plate, and the other end of the movable portion is displaced in the vertical direction to contact the contact plate and turn on. A limit switch that operates, and based on the fact that tension is applied to the power supply cable guided and supported by the support portion, one end side of the movable portion is displaced, and the displacement of the movable portion is accompanied by the displacement. The other end side is displaced in the reverse direction and the limit switch is turned on to detect that a tension has been applied to the power supply cable. The limit switch is activated when the limit switch is turned on. The control means selects one of the plurality of limit switches according to the output of the encoder, and outputs the selected limit switch to the output of the selected limit switch. Based on the above, it is characterized in that the driving means is prohibited from being driven when it is detected that the tension is applied to the power supply cable by the detecting means .

  In the lifting and lowering scaffold device according to the present invention, the contact plate may be attached to the movable portion so that the predetermined interval is adjustable.

  According to the present invention, when the scaffold part is moved up or down, tension is applied to the power supply cable when the power supply cable is hooked on the housing portion of the lifting / lowering scaffold device or the like. In this case, the detection means detects that tension has been applied to the power supply cable, and based on that, the drive means (for example, a motor) is prohibited from being driven. Therefore, since the raising / lowering of the scaffolding portion is stopped before the power supply cable is disconnected during the lifting / lowering operation of the scaffolding portion, it is possible to prevent the power supply cable from being disconnected.

It is a front view which shows the raising / lowering scaffold apparatus which concerns on this invention. The arrangement | positioning relationship of a 1st motor and a 2nd motor, and a pinion is shown, (a) is a side view, (b) is a rear view. It is a front view of a 1st control panel. It is a partial side view which shows the structure of an over tension detection mechanism. It is an AA line partial arrow line view shown in FIG. It is a BB line partial arrow directional view shown in FIG. It is a block diagram which shows the electric constitution of a raising / lowering type scaffold apparatus. It is a figure for demonstrating the effect | action of an overtension detection mechanism, (a) shows a normal state, (b) shows the state in which tension | tensile_strength was added to the power supply cable.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

  FIG. 1 is a front view showing an elevating scaffold device (hereinafter simply referred to as “scaffold device”) according to the present invention. This scaffold device is used for, for example, a temporary scaffold for construction work, and is particularly a lifting type in which a work floor is raised and lowered.

  As shown in FIG. 1, the scaffold device includes two towers. The scaffold device includes a first tower 1 having a predetermined height, a second tower 2 arranged in parallel at a predetermined interval, and a scaffold unit 3 that can be moved up and down supported by both towers 1 and 2. I have. The first tower 1 and the second tower 2 have substantially the same configuration. In the following description, members having the same configuration are denoted by the same reference numerals.

  The first and second towers 1 and 2 have base portions 4 for supporting them with respect to the ground G, respectively. The base part 4 is formed in a substantially flat plate shape, and a plurality of jack mechanisms 5 are provided at corners of the base part 4. The jack mechanism 5 maintains the base part 4 in a horizontal state by adjusting the respective heights.

  The first and second towers 1 and 2 are configured such that a plurality of frame-like members 7 whose outer shapes are formed in a substantially rectangular parallelepiped frame shape are connected. Specifically, in the first and second towers 1 and 2, the lowermost frame-like member 7 is attached at the center of the base portion 4, and another frame-like member 7 is stacked above the frame-like member 7. Configured.

  A rack 8 extending in the vertical direction is provided in the internal space of each frame-like member 7 of the first tower 1. The rack 8 is formed in a long shape, and as shown in FIG. 2 (b), a meshing portion 8a is formed on one end face thereof so that a plurality of pinions 9 are engaged. Similarly, a rack 8 extending in the vertical direction is provided in the internal space of each frame-like member 7 of the second tower 2. The pinion 9 is provided on each of rotation shafts 11a and 12a of first and second motors 11 and 12, which will be described later.

  The 1st tower 1 is provided with the raising / lowering part 10 which can be raised / lowered up and down along it. The raising / lowering part 10 is formed in the substantially rectangular parallelepiped frame shape extended in the height direction. The elevating part 10 is raised and lowered along the outer surface of the frame-like member 7 via a guide roller (not shown). On the other hand, the second tower 2 is also provided with an elevating unit 10 that can be moved up and down along the second tower 2.

  As shown in FIGS. 1 and 2, a first motor 11 and a second motor 12 for raising and lowering the elevator unit 10 are mounted side by side in the vertical direction. The first and second motors 11 and 12 are both induction motors and can be rotated by supplying a power supply voltage. The first and second motors 11 and 12 are each provided with a brake braking function for stopping the rotation when the supply of the power supply voltage is interrupted. Thus, by providing two motors, when one motor fails, the other motor can be used, and safety in an emergency can be ensured.

  The elevating unit 10 is provided with a horizontal moving unit 13 which is disposed so as to cover it and can move horizontally in the front-rear direction (before or in the depth direction in FIG. 1). The horizontal movement part 13 is formed in a substantially rectangular parallelepiped frame shape extending in the front-rear direction. The horizontal moving unit 13 is moved up and down as the lifting unit 10 moves up and down.

  The scaffold part 3 includes an intermediate scaffold part 14 provided between the horizontal movement parts 13 of the first and second towers 1 and 2, and a left side extending in the left direction of the horizontal movement part 13 of the first tower 1. The scaffold portion 15 and the right scaffold portion 16 extending in the right direction of the horizontal moving portion 13 of the second tower 2 are configured. The left scaffolding portion 15 is provided with a leftward advancement / retraction portion 17 that can be advanced and retracted in the left direction. The right scaffolding portion 16 is provided with a rightward advancement / retraction portion 18 that is allowed to advance and retract in the right direction. (FIG. 1 shows a state in which the leftward advance / retreat portion 17 and the rightward advance / retreat portion 18 have advanced).

  Further, the left scaffolding part 15 is rotatable in a fan shape in plan view with the horizontal movement part 13 of the first tower 1 as the center. Further, the right scaffolding portion 16 is rotatable in a fan shape around the horizontal moving portion 13 of the second tower 2.

  The first and second towers 1 and 2 are each provided with a supporting mechanism 19 for supporting and supporting the intermediate scaffold part 14, the left scaffold part 15, and the right scaffold part 16 of the scaffold part 3. The left scaffold portion 15 and the right scaffold portion 16 are respectively supported by the respective supporting mechanisms 19 when they are turned.

  By the said structure, when both the raising / lowering part 10 of the 1st and 2nd towers 1 and 2 raises / lowers, both the horizontal moving parts 13 are raised / lowered, As a result, the scaffold part 3 also raises / lowers. Further, when both the horizontal moving parts 13 are moved in the front-rear direction, the scaffold part 3 is also moved in the front-rear direction.

  In addition, although the scaffold part 3 is classified into the structure of the intermediate | middle scaffold part 14, the left side scaffold part 15, and the right side scaffold part 16 by the difference in an installation site | part, as a common member structure, it forms in the frame shape of a substantially rectangular parallelepiped. A plurality of frame members, a work floor (not shown) which is disposed on the upper surface of each frame member and serves as a stepping floor for the worker, and a plurality of frame members standing on each frame member to prevent the operator from falling And a handrail 20.

  The handrail 20 of the intermediate scaffold section 14 includes a first control panel 21 for controlling the first and second motors 11 and 12 of the first tower 1, and the first and second motors 11 and 12 of the second tower 2. And a second control panel 22 for controlling 12 and the like.

  The scaffold device is provided with a power supply cable 23 (hereinafter referred to as “supply cable”) for supplying a power supply voltage (for example, AC 200 V) from the ground equipment (not shown) to the first control panel 21. The supply cable 23 is housed in the basket 24 on the ground, and one end of the supply cable 23 rises from the basket 24 in the air, and is intermediate via a clamp (not shown) provided in the first tower 1 and an over-tension detection mechanism 30 (described later). It is connected to the first control panel 21 arranged in the scaffold part 14.

  In the intermediate scaffold portion 14, a transition power supply cable 25 for supplying a power supply voltage from the first control panel 21 to the second control panel 22 is laid. Although not shown in the drawings, in this scaffold apparatus, a power cable for supplying a power supply voltage from the first control panel 21 to the first and second motors 11 and 12 of the first tower 1 is laid. A power cable for supplying a power supply voltage from the second control panel 22 to the first and second motors 11 and 12 of the second tower 2 is laid.

  Further, in this scaffold device, an encoder for detecting the raising / lowering position of the raising / lowering unit 10, a plurality of limit switches, a rotating lamp for notifying an operator of an abnormal state, and the like are provided. Since these are controlled by the first control panel 21 and the second control panel 22, a control cable is laid between the first control panel 21 and the second control panel 22 and the encoder and each limit switch. Yes.

  As shown in FIG. 3, the first control panel 21 is provided with a monitor unit 27 and an emergency stop button 28 on the front surface thereof. The monitor unit 27 is configured by a liquid crystal display having a touch panel, and displays the height position of the elevating unit 10 and the like. The emergency stop button 28 is for stopping the raising / lowering of the elevating unit 10 in an emergency.

  An operation box 29 is connected to the first control panel 21. The operation box 29 is used by the operator to input an operation for raising and lowering the scaffold unit 3 such as raising and lowering. The operation box 29 includes an up switch 29a and a down switch 29b (see circles in FIG. 3). The raising switch 29a is for raising the elevating part 10, and the lowering switch 29b is for lowering the elevating part 10.

  As described above, when the raising switch 29a and the lowering switch 29b are operated, the elevating unit 10 is moved up and down, that is, the scaffold unit 3 is moved up and down. The second control panel 22 has the same configuration as the first control panel 21, but the operation box 29 is not connected.

  Here, the over-tension detection mechanism 30 which is a characteristic part of the present embodiment will be described.

  The over-tension detection mechanism 30 is for preventing the supply cable 23 from being disconnected. As shown in FIGS. 1 and 4, the over-tension detection mechanism 30 is, for example, in the vicinity of the first control panel 21 disposed in the intermediate scaffold portion 14 and below the framework member 14 a constituting the intermediate scaffold portion 14. Is provided.

  The over-tension detection mechanism 30 includes a movable portion 31 that can freely operate a seesaw with a predetermined portion as a fulcrum, and a cable support portion 32 that is provided at a front end portion of the movable portion 31 to guide and support a part of the supply cable 23. And a detection unit 33 that is provided at the rear end of the movable unit 31 and detects that an overtension is applied to the supply cable 23. A buffer part 34 for absorbing a stroke in the seesaw operation of the movable part 31 is provided at the end of the movable part 31.

  The movable portion 31 is composed of a plurality of elongated prismatic members extending in the front-rear direction. One end of the movable portion 31 is supported by a pair of first support plates 35 attached to the frame member 14a of the intermediate scaffold portion 14 so that a seesaw operation is possible. In the movable portion 31, the other end portion of the first support plate 35 is pivotally supported by the support shaft 35a.

  The cable support portion 32 includes an arcuate member 36 having a substantially U shape in cross section and a curved surface member 37 provided at the base end of the arcuate member 36. One end of the arc-shaped member 36 is fixed to the front end portion of the movable portion 31. The curved surface member 37 is supported by shafts 38 a of a pair of second support plates 38 provided at the front end portion of the movable portion 31. The second support plate 38 is formed in a substantially U shape, and a shaft 38a is pivotally supported at the bent portion. A guide piece 37a is formed on the end surface in the width direction of the curved member 37 (see FIG. 5).

  The supply cable 23 is once laid along the circumferential surface of the curved surface member 37 from the first control panel 21, and the supply cables 23 are fastened at one end of the arcuate member 36 by a fastening member 39 such as a number wire. Further, the supply cable 23 is fixedly supported by a bracket 36a in the middle of the arc-shaped member 36, and is guided by the arc-shaped member 36 as it is and is hung downward. Thus, the supply cable 23 is firmly fixed to the cable support portion 32 by the fastening member 39 and the bracket 36a. In this case, since the supply cable 23 runs along the surface of the curved member 37, the damage can be suppressed as much as possible, and the tension applied to the supply cable 23 reaches the first control panel 21. Can be suppressed.

  The detection unit 33 detects a vertical displacement on the other end side of the movable unit 31. That is, the detection unit 33 detects that the tension is applied to the supply cable 23 and the movable unit 31 that rotates with the support shaft 35a serving as a fulcrum has a predetermined inclination angle or more. The detection unit 33 includes, for example, a limit switch 40 supported by the frame member 14a, and a contact plate 41 supported by the movable unit 31 with a predetermined distance from the limit switch 40. The limit switch 40 includes a substantially rectangular parallelepiped main body 42 having a switch portion, and an actuator 43 connected to the main body 42 and swingable in a vertical direction. The actuator 43 has a lever and a substantially cylindrical roller provided at the tip of the lever.

  The limit switch 40 is attached to a support plate 44 provided along the vertical direction on the rear side of the frame member 14a. The limit switch 40 is supported so that the actuator 43 is bent with respect to the main body 42 in a normal state. The limit switch 40 is turned on when the actuator 43 is tilted by an external force and reaches a predetermined angle, for example, outputs a contact signal to the outside. In the present embodiment, the contact signal is sent to the first control panel 21 through the control cable 45.

  As shown in FIG. 6, the contact plate 41 is formed in a substantially L shape in a cross-sectional view, and has a horizontal surface portion 41 a and a vertical surface portion 41 b. The contact plate 41 is attached to a side surface near the rear end side of the movable portion 31 by a bolt 31a so that the horizontal surface portion 41a is positioned at a predetermined distance from the tip of the actuator 43 in a normal state. Has been placed.

  Although not shown, a through hole for penetrating the bolt 31a is formed in the vertical surface portion 41b of the contact plate 41, and the through hole is a long hole. By changing the fixing position of the bolt 31a with respect to the elongated hole, the height position of the contact plate 41 can be changed. That is, the distance between the horizontal surface portion 41 a of the contact plate 41 and the tip of the actuator 43 is adjustable.

  Thereby, the timing at which the movable part 31 turns on the limit switch 40 can be changed, that is, the degree of tension applied to the supply cable 23 to be detected can be adjusted. For example, if the distance between the horizontal surface portion 41a of the contact plate 41 and the tip of the actuator 43 is adjusted to be short, the limit switch 40 is turned on when the inclination of the movable portion 31 is small, so that the tension applied to the supply cable 23 It is possible to detect even when is small. Further, if the distance between the horizontal surface portion 41a of the contact plate 41 and the tip of the actuator 43 is adjusted to be long, the limit switch 40 is turned on when the inclination of the movable portion 31 is large. A case where the tension is large can be detected.

  The buffer part 34 consists of coil springs, for example, and absorbs the inclination of the movable part 31 that rotates around the support shaft 35a. The buffer portion 34 has an upper end fixed to the rear end of the frame member 14 a and a lower end fixed to the rear end of the movable portion 31.

  FIG. 7 is a block diagram showing an electrical configuration of the scaffold device. In this scaffold device, the first control panel 21 is provided with a control unit 26 composed of, for example, a sequencer. The monitor unit 27 and the emergency stop button 28 described above are connected to the control unit 26. The control unit 26 sends display data to be displayed to the monitor unit 27 and performs various data processing based on operation signals from the monitor unit 27 using the touch panel. When the pressing signal from the emergency stop button 28 is input, the control unit 26 controls to forcibly stop the rotational driving of the first and second motors 11 and 12.

  An operation box 29 is connected to the control unit 26, and the first and second motors 11 and 12 of the first tower 1 are connected. When the ascending switch 29a and the descending switch 29b of the operation box 29 are pressed, the control unit 26 receives these operation signals, and responds to these operation signals to the first and second motors 11 and 12. Each drive signal is sent out. Based on these drive signals, the first and second motors 11 and 12 are rotated forward or backward, whereby the scaffold 3 moves up and down.

  Further, the above-described limit switch 40 for detecting overtension is connected to the control unit 26. The control unit 26 controls to stop the rotational driving of the first and second motors 11 and 12 when a signal indicating that an overtension is applied to the supply cable 23 from the limit switch 40. At the same time, the fact is transmitted to the second control panel 22, and the second control panel 22 stops the rotational driving of the first and second motors 11 and 12 of the second tower 2. Thereby, the raising / lowering of the scaffold part 3 is forcibly stopped.

  Next, the operation of the overtension detection mechanism 30 will be described.

  For example, when an operator inputs an operation of the ascending switch 29a on the first control panel 21, the first and second motors 11 and 12 of the first and second towers 1 and 2 are both rotationally driven. Thereby, the raising / lowering part 10 is raised, ie, the scaffold part 3 is raised.

  In this case, the power supply voltage is supplied to the first control panel 21 from the ground facility via the supply cable 23. Further, the weight of the supply cable 23 is applied to the cable support portion 32 of the over-tension detection mechanism 30 as a load.

  Here, for example, when the supply cable 23 is tensioned for some reason (for example, hooked on the basket 24), and the scaffold part 3 is further lifted in this state, the supply cable 23 is further tensioned. Therefore, the supply cable 23 is likely to be disconnected by this tension. Since the overstrength detection mechanism 30 is provided in the scaffold device of this embodiment, the disconnection of the supply cable 23 can be prevented in advance.

  That is, when a tension is applied to the supply cable 23 as shown in FIG. 8B with respect to the normal state shown in FIG. 8A, it is also applied to the cable support 32 (see arrow C). ), The tip of the arcuate member 36 is pulled downward. Therefore, one end of the movable part 31 is displaced downward, and rotates in the clockwise direction with the support shaft 35a as a fulcrum. As a result, the other end of the movable portion 31 is displaced upward, and the surface of the horizontal surface portion 41 a of the contact plate 41 contacts the tip of the actuator 43.

  And if the raising of the scaffold part 3 is continued and further tension is applied to the supply cable 23, the movable part 31 further rotates in the clockwise direction. Therefore, the horizontal surface portion 41a pushes the tip of the actuator 43 and the other end of the movable portion 31 is displaced upward (see arrow D) until the actuator 43 is inclined to approach the horizontal state.

  As a result, the limit switch 40 is turned on, and a signal indicating that an overtension is applied to the supply cable 23 is output from the limit switch 40 to the first control panel 21, and the control unit 26 of the first control panel 21. Outputs a drive stop signal to the first and second motors 11 and 12. Therefore, the rotation of the first and second motors 11 and 12 is forcibly stopped, the ascending operation of the elevating unit 10 is stopped, that is, the ascending operation of the scaffold unit 3 is stopped. Therefore, no further tension is applied to the supply cable 23, and disconnection of the supply cable 23 can be prevented in advance.

  As described above, according to the present embodiment, when tension is applied to the supply cable 23 while the scaffold unit 3 is moved up and down, the movable unit 31 performs a seesaw operation, which is appropriately detected by the limit switch 40, and the scaffold unit 3. Therefore, it is possible to prevent the supply cable 23 from being disconnected with a simple structure.

  For example, a commercially available load cell may be used to detect the tension applied to the supply cable 23, but the load cell is generally expensive. In the present embodiment, since the tension applied to the supply cable 23 can be detected without using such an expensive load cell, the disconnection of the supply cable 23 can be prevented at a low cost.

  The scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. In the above embodiment, only one limit switch 40 is provided, but instead of this, a plurality of limit switches having different inclination angles of the movable part 31 at the time of the on operation are provided, and the control part 26 is an encoder One of the limit switches may be selected according to the value (height position), and the first and second motors 11 and 12 may be stopped based on the output of the selected limit switch.

  That is, when the height range in which the scaffold part 3 moves up and down is increased, the weight applied to the arc-shaped member 36 due to the weight of the supply cable 23 may vary greatly depending on the height position of the scaffold part 3. Specifically, the higher the elevation of the scaffold part 3 is, the greater the weight of the supply cable 23 is applied to the arc-shaped member 36. In this case, the movable part 31 is easily inclined and the limit switch is also easily turned on. Therefore, the control unit 26 selects a limit switch that is less likely to be turned on from the plurality of limit switches as the lifting / lowering height of the scaffold unit 3 is higher, and the first and second limit switches are selected based on the turn-on operation of the limit switch. If the two motors 11 and 12 are stopped, it is possible to perform control in consideration of the weight of the power supply cable 23.

  Further, for example, the number, form, configuration, and the like of the members constituting the overtension detection mechanism 30 in the above embodiment are not limited to those in the above embodiment. For example, a limit switch is used for the detection unit 33, but the present invention is not limited to this. Moreover, in the said embodiment, although the movable part 31 was set as the structure suspended from the intermediate | middle scaffold part 14, it may replace with this and the structure deferred may be sufficient. Further, in the above embodiment, the limit switch 40 is provided in the intermediate scaffold part 14, but instead, the limit switch 40 is provided in the movable part 31 and the contact plate 41 is provided in the intermediate scaffold part 14. It may be.

  According to the above-described embodiment, when detecting that the tension is applied to the supply cable 23 and stopping the raising operation of the scaffold part 3, the operator may be notified of this. For example, a rotating lamp may be operated. In the above embodiment, when tension is applied to the supply cable 23, one end of the movable part 31 is displaced downward. However, instead of this, one end of the movable part 31 may be displaced upward.

  The configurations of the first and second towers 1 and 2, the scaffold unit 3, the elevating unit 10, and the first and second motors 11 and 12 can be appropriately changed in design. For example, in the above embodiment, the two towers 1 and 2 are provided, but the lifting and lowering scaffolding device may be configured by one or three or more towers.

DESCRIPTION OF SYMBOLS 1 1st tower 2 2nd tower 3 Scaffolding part 10 Lifting part 11 First motor 12 Second motor 13 Horizontal moving part 14 Intermediate scaffold part 21 First control panel 23 Power supply cable 26 Control part 30 Over tension detection mechanism 31 Movable part 32 Cable support part 33 Detection part 40 Limit switch 41 Contact plate

Claims (2)

A tower portion extending vertically, and
An elevating part provided so as to be movable up and down along the tower part;
A driving means provided in the elevating unit for applying a driving force for elevating the elevating unit;
A scaffold part that is provided in a lateral direction of the lifting part and that moves up and down as the lifting part moves up and down;
An encoder for detecting a height position of the scaffold part;
A power supply cable for supplying the power supply voltage for driving the drive means from ground equipment provided on the ground, and
Detecting means for detecting that a tension is applied to the power supply cable during the lifting and lowering operation of the scaffold part;
Control means for prohibiting driving of the driving means when it is detected by the detecting means that a tension is applied to the power supply cable;
Equipped with a,
The detection means includes
A long movable part supported on the scaffold part so as to freely operate a seesaw; and
A support portion that is provided on one end side of the movable portion and guides and supports a part of the power supply cable;
A contact plate supported on the other end of the movable part;
The scaffold portion is supported with a predetermined distance from the abutment plate, and the movable portion other end side is displaced in the vertical direction so that it comes into contact with the abutment plate and is turned on.
Based on the tension applied to the power supply cable guided and supported by the support portion, one end side of the movable portion is displaced, and the other end side of the movable portion is displaced in the reverse direction along with the displacement. When the limit switch is turned on, it detects that a tension is applied to the power supply cable.
The limit switch is
It consists of a plurality of limit switches with different tilt angles of the movable part when turning on,
The control means includes
Select one of the limit switches according to the output of the encoder,
A lifting and lowering scaffold characterized in that , based on the output of the selected limit switch, the detection means prohibits driving of the driving means when it is detected that a tension is applied to the power supply cable. apparatus. The contact plate is
The lifting and lowering scaffolding device according to claim 1 , wherein the predetermined interval is attached to the movable part so as to be adjustable.

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