JP3156737B2 - lift device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lifting device having a fall prevention device.

[0002]

2. Description of the Related Art Conventionally, a lifting device described in Japanese Utility Model Publication No. Sho 55-20007 or Japanese Patent Publication No. Sho 56-20463 is known.

[0003] These elevating devices are used in lighting devices, in which a movable table fitted on a pole is hung by a wire, and the wire is wound by a motor or the like to raise or lower the movable table. A fall prevention device is connected to the distal end of the wire so that the movable table does not fall even if the wire is cut. And this fall prevention device has a rotatable locking claw connected to the distal end of the wire, and when the wire is cut and loosened, the locking claw rotates and bites into the pole, The movable platform is stopped.

[0004]

In the above-mentioned conventional configuration,
Although the movable table can be reliably prevented from falling, there is a problem that when the movable table is subjected to strong wind, vibration, or the like during the elevating operation of the movable table, the movable table cannot slide up and down smoothly due to sliding contact with a pole.

The present invention has been made in view of the above points, and an object of the present invention is to provide a lifting apparatus capable of reliably preventing the movable table from falling and preventing the movable table from being biased so as to smoothly move up and down. I do.

[0006]

According to a first aspect of the present invention, there is provided an elevating device, wherein an upright pole whose diameter decreases in a tapered shape as it goes upward, a movable table inserted into the pole so as to be able to move up and down, and A cable for suspending the movable table, driving means for driving the cable, and a fall prevention device provided on the movable table, wherein the fall prevention device detects a tension of the cable; A swing arm that is always rotatably supported and elastically abuts on the peripheral surface of the pawl; and a rotation prevention that prevents rotation of the swing arm in accordance with an input from the tension detecting means. Means.

A lifting device according to a second aspect of the present invention is the lifting device according to the first aspect, wherein the pressing portion is provided at the distal end portion of the swing arm so as to be elastically movable forward and backward, and constantly contacts the peripheral surface of the pole. Detecting means for detecting the forward / backward state of the section;
Control means for stopping the driving means in accordance with the input from the detecting means.

[0008]

In the lifting device according to the first aspect, the rope is driven by the driving means at all times, and the movable table suspended by the rope moves up and down along the pole. At the time of this elevating operation, the swing arm of the fall prevention device is elastically abutted on the peripheral surface of the pole while rotating, so that the movable table is prevented from being biased and smoothly moved up and down. When the tension of the rope becomes inactive, the rotation of the swing arm is prevented by the rotation preventing means in accordance with the input from the tension detecting means for detecting the tension of the rope. Then, since the diameter of the pole is tapered toward the lower side, when the movable table is lowered, the swing arm, whose rotation is prevented, comes into contact with the peripheral surface of the pole and the movable table is stopped.

In the lifting device according to the second aspect, a pressing portion which is always in contact with the peripheral surface of the pole is provided at the tip of the swing arm so as to be elastically movable forward and backward. The driving means is stopped by the control means according to the input from the means. Therefore, if the movable table is deviated during the up / down operation of the movable table, the pressing portion that is always in contact with the peripheral surface of the pole moves forward and backward, the driving means is stopped, and the up / down operation of the movable table is stopped.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a lifting device according to an embodiment of the present invention.

In FIGS. 1 and 2, reference numeral 11 denotes a pole of a lighting device standing on the ground. A plurality of the poles 11 are installed, for example, on a tarmac (apron) of an airfield and have a height of 20 to 30 m. It is formed in a substantially cylindrical shape having an outer diameter smaller in a tapered shape upward. A substantially disk-shaped fixing base 12 is provided at the upper end of the pole 11, and three pulleys 14 on which a wire W as a cable is mounted are formed in a pair on the upper part of the fixing base 12. It is rotatably supported by a substantially L-shaped pulley support plate 15. In addition, these pulleys 14 are arranged at equal intervals radially with respect to the center axis of the pole 11, that is, the wires W mounted on these pulleys 14 are also arranged at equal intervals radially with respect to the center axis of the pole 11. Are located.

Further, through holes 16 are formed in the fixed base 12 at positions before and after each pulley 14, and each end of the wire W is inserted into the inside of the pole 11 and the outside of the pole 11 by inserting the front and rear through holes 16 respectively. Hanging. A drive device 18 as a drive unit having a motor M for winding the wires W and a balance weight (not shown) are connected to the inner end of each wire W.

A movable table 21 which is vertically movably inserted into the pole 11 is connected to the outer end of each wire W, and the movable table 21 is suspended and supported by these wires W. As shown in FIGS. 1 to 3, the movable base 21 includes a tubular inner ring portion 22 that fits loosely on the pawl 11 and a tubular outer ring portion 23 located on the outer periphery of the inner ring portion 22. Are connected by a plurality of radially provided vertical support plate portions 24, and the upper and lower surfaces are closed by annular upper and lower plates 25 and 26, respectively. Also, this movable platform
As shown in FIG. 3, the flange 21a is formed into two parts on both sides, and a flange portion 21a is formed in a thin portion at each connection portion. These flange portions 21a are joined to each other by bolts (not shown) to form a pole 11a. It is designed to be assembled near the ground while being loosely fitted.

A plurality of lamps (projectors) for illuminating a wide area such as an aerodrome parking area (apron) are provided on the outer periphery of the movable base 21 via arms 28, respectively.
29 is installed.

The movable table 21 is provided with fall prevention devices 31 at three locations corresponding to the respective wires W. The fall prevention device 31 has tension detecting means 32 for detecting a tension state of the wire W. This tension detecting means
Reference numeral 32 denotes a detection roller 35 abutting on the inner side near the outer end of the wire W, a pair of support arms 36 for sandwiching and supporting the detection roller 35, and a cart-like linear motion supporting the support arm 36. The linear motion guide portion 37 is mounted on the upper plate 25 of the movable base 21 so as to be able to advance and retreat in the radial direction of the movable base 21. A spring support 38 is erected near the outer end on the upper plate 25 of the movable base 21, and a spring body stretched between the spring support 38 and the support arm 36 is provided.
The support arm 36 and the linear motion guide 37 are constantly urged outward by the 41, and are positioned inside and locked by the detection roller 35 in contact with the wire W.

Further, a pair of link bases 43 on both sides are fixed in the movable base 21 under the tension detecting means 32,
A link shaft 44 is provided between the link tables 43, and the vicinity of the center of a pair of link levers 45 on both sides is rotatably supported by the link shaft 44. In the vicinity of the upper and lower ends of these link levers 45, long holes 45a and 45b are provided, respectively.
Are formed, and a linear motion guide portion is provided in each of the upper long holes 45a.
Fixed shafts 37a protruding from both sides of the 37 are rotatably engaged with each other, and these link levers 45 rotate as the linear guide 37 advances and retreats.

A pair of rotation stop lever bases 46 are fixed to the movable base 21 under the link levers 45, and a rotation stop lever shaft 47 is provided between the rotation stop lever bases 46. The rotation stopper lever shaft 47 is rotatably supported in the vicinity of the lower end of a rotation stopper lever 48 as a rotation preventing means. Support shafts 49 protrude from both sides near the upper end of the rotation stop lever 48, and these support shafts 49 are rotatably engaged with the long holes 45b below the link lever 45, respectively. In addition, from the vicinity of the upper end of the rotation stop lever 48,
51 are protruding. The locking claw 51 has a lower surface formed substantially perpendicular to the longitudinal direction of the rotation stop lever 48 and an upper surface formed to be inclined.

A pair of swing arm tables 53 on both sides are fixed in the movable table 21 inside the rotation stop lever 48, that is, on the pole 11 side.
A swing arm shaft 54 is provided between the swing arm shafts 54, and the vicinity of the base end of the swing arm 55 is rotatably supported by the swing arm shaft 54. A substantially cylindrical ratchet portion 57 centering on the swing arm shaft 54 is formed at the base end of the swing arm 55, and the locking claw 51 of the rotation stop lever 48 is selectively provided on the outer periphery of the ratchet portion 57. Are formed continuously.

The vicinity of the tip of the swing arm 55 is divided into two parts on both sides, and a pair of long holes 61 on both sides are formed along the longitudinal direction of the swing arm 55. At the tip of the swing arm 55, a disc-shaped pressing roller 62 as a pressing portion is provided so as to be able to protrude and retract. The pressing roller 62 is rotatably supported by a roller receiver 63, and the roller receiver 63 has shaft portions projecting from both sides.
The roller holder 63 is urged toward the distal end of the swing arm 55 by a spring body 66 built into the swing arm 55, while the roller holders 64 are respectively supported by engaging with the long holes 61 of the swing arm 55 so as to be able to advance and retreat. The pressing roller 62 is normally supported so as to protrude from the tip of the swing arm 55.

Further, spring posts 68 and 69 project from both sides near the distal end of the swing arm 55 and both sides of the linear guide 37 of the tension detecting means 32, respectively. , 69, a spring body 71 is stretched. And this spring body
Due to the urging force of 71, the vicinity of the distal end of the swing arm 55 is urged in the direction of turning upward, and the pressing roller 62 at the distal end of the swing arm 55 always contacts the peripheral surface of the pole 11 and the movable table 21 The pressing roller 62 rolls on the peripheral surface of the pole 11 with the ascent and descent. A micro switch 73 as a pair of upper and lower detecting means is attached near the tip of the swing arm 55,
The circuit is opened and closed as the roller receiver 63 supporting the shaft 62 advances and retreats.

In FIGS. 2 and 3, reference numeral 76 denotes a positioning device. The positioning device 76 has a portion exposed to the outside made of stainless steel and is provided in a pair at positions facing each other with the pole 11 interposed therebetween. Fixed base on top of pole 11
It comprises a guide mechanism 77 attached to the lower surface of 12 and a pin portion 78 attached to the upper surface of the upper plate 25 of the movable base 21 so as to face the guide mechanism 77.

The pin 78 is a disk-shaped pedestal.
81 and a positioning pin 82 protruding upward from the center of the pedestal portion 81. And this positioning pin
The upper end of 82 has a slight flat portion 82a and is cut in a tapered shape to form an inclined surface portion 82b.

The guide mechanism 77 has a substantially L-shaped bracket 84 attached to the lower surface of the fixed base 12, and a pair of upper and lower horizontal support plates 85 and 86 fixed to the bracket 84. ing. The support plates 85 and 86 are formed with vertically communicating circular holes 85a and 86a.
A columnar rod 88 is mounted in a state where 86a is inserted. A collar 89 having a large diameter is provided near the upper end of the rod 88, and the range of movement of the rod 88 downward is restricted. A substantially cylindrical guide plate 90 is attached to the lower end of the rod 88.
A substantially conical guide concave portion 92 which is expanded downward and in which the positioning pin 82 is fitted so as to be able to freely come and go is recessed. The guide recess 92 has a cylindrical shape in which the diameter of the lower opening is larger than the diameter of the positioning pin 82 and the upper part has a diameter smaller than the diameter of the flat portion 82a at the upper end of the positioning pin 82. The part 93 is formed continuously. Further, between the lower support plate 86 and the guide plate 90, a spring body 95 fitted to the rod 88 is mounted to urge the guide plate 90 downward.

As shown in FIGS. 1, 2 and 5, a driving device having a motor M
The pole 11 is provided with a window 101 used for operating the driving device 18 and the like.
Is always closed by the door 102. The drive device 18 inside the pole 11 includes a motor M, a power supply line 106 connected to a three-phase power supply via a circuit breaker (MCCB) 105, a micro switch 73, and a limit switch 83. The connected connectors 107 are provided, and a hook holder (not shown) is provided in a part of the driving device 18 or the pole 11.

In FIGS. 5 and 6, reference numeral 111 denotes a portable control device as control means.
Is connected to an engaging portion 112 which is mechanically held by being engaged with a hook holding portion of the driving device 18, a handle 114 for carrying the control device 111, and a connector 107 of the driving device 18. A connector 115 and a plurality of operation switches 116 are provided. Further, inside the control device 111, a CPU (not shown) for controlling the rotation direction and the rotation speed of the motor M, and drive programs respectively suitable for the drive devices 18 provided on the poles 11 of the plurality of lighting devices are stored. ROM and the like are provided.

The operation switches 116 include a forward command switch 116a, a reverse command switch 116b, a low speed command switch 116c, a reset input switch 116d, and a stop command switch.
116e etc., the connector 107 of the drive unit 18 and the control unit
By operating the respective operation switches 116 in a state where the connector 115 is connected to the connector 115, the movable base 21 can be moved up and down by freely controlling the motor M, and each micro switch 73 and limit switch 83
The motor M can be automatically controlled in accordance with the input from the controller.

Further, when the movable table 21 is not to be moved up and down, the control device 111 disconnects the connectors 107 and 115 from each other and removes them from the drive device 18 so that they can be stored separately. By sequentially connecting to the driving devices 18 provided on the poles 11 of the apparatus, the driving devices 18 of the respective poles 11 can be controlled.

The control device 111 is grounded on the ground E while mounted on the drive device 18.

Next, the operation of this embodiment will be described.

First, with the movable table 21 lowered to the lowermost limit, the lamp of the lamp body 29 is replaced and inspected, or the initial movable table 21 is assembled.

Then, the control device 111 is mounted on the drive device 18, and the forward rotation command switch 116a is pushed while the connector 107 of the drive device 18 and the connector 115 of the control device 111 are connected, so that the motor M Rotates forward at a predetermined speed, winds up the wire W, and raises the movable base 21 along the pole 11.

In this state, since the wire W is in tension, the detection roller 35 provided on the fall prevention device 31 is in contact with the wire W, and the tension detection means 32 provided on the movable base 21 is directly moved. The dynamic guide 37 is located radially inside the movable base 21 against the urging force of the spring body 41. At this time, the link lever 45 connected to the linear motion guide 37
, The upper end is turned inward and the lower end is turned outward. Accordingly, the rotation stop lever 48 connected to the link lever 45 also has its upper end rotated outward about the rotation stop lever shaft 47, and the locking claw 51 formed on the rotation stop lever 48.
And the ratchet portion 57 formed on the swing arm 55 are separated from each other.
It is rotatable around 54. Therefore, the tip of the swing arm 55 is rotated upward by the urging force of the spring body 71, and the pressing roller 62 provided at the tip of the swing arm 55 elastically abuts on the peripheral surface of the pole 11 and rolls. Move. Since the fall prevention devices 31 are provided at three places around the pole 11, the pressing roller 62 always elastically contacts the pole 11 from three directions, and the movable roller 21 is almost not biased. Holds horizontally.

In the event that the movable table 21 swings and tilts due to wind pressure load due to strong wind or vibration such as an earthquake, a roller receiver 63 supporting the pressing roller 62 of one swing arm 55 is provided with a spring body. Retreat against 66 forces. The movement of the roller receiver 63 is detected by the micro switch 73 attached to the swing arm 55, and the motor M of the driving device 18 is stopped. When the movable base 21 is near the lower end of the pole 11, for example, there are cases where all three micro switches 73 are activated by retreating all three roller receivers 63 that support the pressing roller 62. It is determined that there is no eccentricity of the movable base 21, and the motor M of the driving device 18 does not stop.

Then, with the movable base 21 approaching the upper end of the pole 11, the automatic low-speed command switch 116c
, The motor M is driven at a low speed to prevent the motor M from being overloaded.

Further, when the movable base 21 approaches the upper end of the pole 11, the positioning pins 82 of the pin portions 78 provided on the upper end of the movable base 21 are brought into contact with the guide plate of the guide mechanism 77 provided on the lower surface of the fixed base 12. It is inserted into the guide recess 92 of the 90. A tapered inclined surface portion 82b is formed at the tip of the positioning pin 82, and the guide concave portion 92 is also formed in a substantially conical shape expanding downward, so that, for example, a wind pressure load due to strong wind or an earthquake. In the event that the movable table 21 swings and tilts due to vibrations, etc., the movable table 21 is raised by sliding contact between the guide recesses 92 of the two guide plates 90 and the inclined surface portions 82b of the positioning pins 82. The position of the movable base 21 is restricted, and the center axis of the pole 11 and the center axis of the movable base 21 are aligned.

The guide recesses of the two guide plates 90
In a state where the 92 and the inclined surface portion 82b of the positioning pin 82 are completely fitted, the center axis of the pole 11 and the center axis of the movable base 21 are aligned, and the center axis of the movable base 21 is inserted into the rod 88 of each guide mechanism 77. The guide plate 90 is elastically supported in a state of being pressed substantially vertically downward by the biasing force of the
Regardless of the weight balance of 21, the movable table 21 is positioned and fixed while keeping substantially horizontal. Also, in this state,
The limit switch 83 is pushed, and the motor M is stopped.

If the wire W is loosened by cutting or the like, the detection roller 35 provided on the fall prevention device 31
Is released, and the linear guide 37 of the tension detecting means 32 provided on the movable base 21 is moved radially outward of the movable base 21 by the urging force of the spring body 41. Then, the link lever 45 connected to the linear motion guide portion 37 rotates around the link shaft 44 at the upper end side outward and the lower end side inward, and the rotation stop lever connected to the link lever 45. 48 rotates inward at the upper end side around the rotation stop lever shaft 47. Then
The locking claw 51 formed on the rotation stopping lever 48 selectively engages with one of the engaging concave portions 58 formed on the ratchet portion 57 of the swing arm 55, and prevents the swing arm 55 from rotating at least upward. It is fixed. The movable platform in this state
When 21 moves downward, the diameter of the tapered pole 11 gradually increases downward, so that the pressing roller 62 provided at the tip of the swing arm 55 is pressed against the peripheral surface of the pole 11 and gradually retracts outward. Then, the tip of the swing arm 55 comes into contact with the peripheral surface of the pole 11, engages and engages, and the movable table 21 is stopped.

As described above, according to the elevating device of the present embodiment, the fall prevention device 31 which abuts on the peripheral surface of the pole 11 in a state where the wire W is relaxed, bites and engages to stop the movable base 21 is provided. Since three positions are provided, even in the event that the wire W is cut, the movable stand 21 can be securely stopped by the fall prevention device 31 with a simple configuration to prevent the fall, thereby improving safety. .

Since all of the fall prevention devices 31 operate mechanically, they can be reliably stopped regardless of the presence or absence of a power supply.

When the movable table 21 is moved up and down, the pressing roller 62 provided on the fall prevention device 31 is always elastically contacted with the pole 11 from three directions. The movable table 21 is supported without being in direct sliding contact with the pole 11 and without being eccentric while maintaining a substantially horizontal position. Therefore, the swing, eccentricity, rotation of the pole 11 in the circumferential direction, and the like during the raising and lowering operation of the movable base 21 are suppressed, and the raising and lowering operation of the movable base 21 can be stabilized, and the reliability can be improved. The replacement of the lamp of the lamp body 29, the inspection work and the like can be facilitated quickly.

When the movable table 21 is moved up and down,
If 21 is eccentric, this eccentricity is
Is detected and the motor M of the driving device 18 is immediately stopped, so that sliding contact between the movable base 21 and the pawl 11 is prevented, and safety can be further improved.

Further, a positioning mechanism 76 comprising a guide mechanism 77 attached to the fixed base 12 at the upper end of the pole 11 and a pin 78 attached to the upper surface of the movable base 21 is provided at two places. The sliding contact between the guide recess 92 of 90 and the inclined surface 82b of the positioning pin 82 makes the center axis of the pole 11
The center of the movable plate 21 can be aligned with the center axis of the movable plate 21, and the movable table 21 can be positioned and fixed in a state of being kept substantially horizontal by the elastic force of the spring body 95 supporting the guide plate 90. Therefore, the positioning and fixing of the movable table 21 can be performed easily and smoothly, as compared with the conventional case where the roller provided on the movable table is pressed against the fixed guide plate to perform positioning.
The movable table 21 can be positioned and fixed while maintaining a substantially horizontal state regardless of the weight balance of the 21.

The control device 11 for controlling the driving device 18
1 can be carried separately from this drive device 18. Therefore, even when a large number of poles 11 are erected, each drive device 18 can be controlled and operated by one control device 111. Therefore, the cost can be reduced by sharing the control device 111. Further, the control device 111 having a semiconductor such as a CPU and a ROM can be stored indoors, not in the pole 11 exposed to the outside air.
The life of 111 can be extended and its reliability can be improved.
In addition, since the control device 111 can be stored indoors in this manner, it is not necessary to increase the waterproof performance or the like more than necessary, and the control device 111 having a simplified structure can be used. Since the movable table 21 is raised and lowered for inspection and replacement of the lamp body 29 and the lamp, the frequency of the vertical movement is low, and it is rare that the plural movable tables 21 are raised and lowered at the same time. Therefore, no problem occurs even if the control device 111 is shared in this way.

Further, since the movable base 21 is formed in two parts on both sides and assembled near the ground in a state where the movable base 21 is inserted into the pole 11, it is possible to lift the movable base 21 above the pole 11 by a crane truck, Guidance work or the like on the bucket part of the aerial work vehicle is not required, so that work safety can be improved and construction time and construction costs can be reduced.

In this embodiment, one pressing roller 62 is supported at the tip of the swing arm 55, but a plurality of pressing rollers 62 may be supported on the pole 11 to contact the pole 11. Alternatively, the distal end of the swing arm 55 can be brought into sliding contact with the pole 11 without providing the pressing roller 62.

In this embodiment, a substantially conical guide concave portion 92 is formed on the lower surface of the guide plate 90, and the upper portion of the guide concave portion 92 is continuous with the diameter of the flat portion 82a at the upper end of the positioning pin 82. Although the cylindrical portion 93 having a small diameter is formed, the cylindrical portion 93 does not have to be formed, and the diameter of the cylindrical portion 93 is formed substantially equal to the positioning pin 82,
The cylindrical portion 93 and the positioning pin 82 can be fitted to each other to ensure reliable positioning.

In this embodiment, the lamp 29 is mounted on the movable base 21.
The arm 28 is supported by an arm 28 projecting from the side of the movable table 21. However, the arm 28 can be protruded from the upper surface of the movable base 21.

Further, in this embodiment, the wire W is used as the cord, but a chain or a fiber rope may be used.

[0049]

According to the first aspect of the present invention, the rope is constantly driven by the driving means, and the movable table suspended by the rope moves up and down along the pole. During this elevating operation, the swing arm of the fall prevention device is elastically brought into contact with the peripheral surface of the pole while rotating, so that the movable table can be prevented from being biased and the movable table can be raised and lowered smoothly. . When the tension of the rope becomes inactive, the rotation of the swing arm is prevented by the rotation preventing means in accordance with the input from the tension detecting means for detecting the tension of the rope. Then, since the diameter of the pole is tapered toward the lower side, when the movable table is lowered, the swing arm, whose rotation is prevented, comes into contact with the peripheral surface of the pole.
Then, the movable table is stopped by the frictional resistance between the swing arm and the pole, so that the movable table can be reliably prevented from dropping and safety can be improved.

According to the lifting device of the second aspect, the pressing portion which is always in contact with the peripheral surface of the pawl is provided at the tip end of the swing arm so as to be able to reciprocate elastically. The driving means is stopped by the control means according to the input from the detecting means. Therefore, if the movable table is biased during the up and down operation of the movable table, the pressing unit that constantly contacts the peripheral surface of the pole advances and retreats, so it is possible to stop the driving means and stop the up and down operation of the movable table. And safety can be improved.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing one embodiment of a lifting device according to the present invention.

FIG. 2 is a side view of the lighting device.

FIG. 3 is an exploded perspective view of the gantry.

FIG. 4 is a side view of the positioning device.

FIG. 5 is a configuration diagram of a driving device and a control device according to the embodiment.

FIG. 6 is a perspective view of the control device.

[Explanation of symbols]

 11 Pole 18 Driving device as driving means 21 Movable table 31 Fall prevention device 32 Tension detecting means 48 Non-rotating lever as rotation preventing means 55 Swing arm 62 Press roller as pressing part 73 Microswitch as detecting means 111 Control means Control device W Wire as cable

Claims (2)

(57) [Claims] An upright pole whose diameter decreases in a tapered shape as it goes upward, a movable base fitted to the pole so as to be able to move up and down, a rope hanging the movable base, and a drive of the rope. And a fall prevention device provided on the movable base, wherein the fall prevention device includes: a tension detection unit that detects a tension of the cable; An elevating device comprising: a swing arm elastically abutting on a peripheral surface of the pawl; and a rotation preventing means for preventing rotation of the swing arm in accordance with an input from the tension detecting means. 2. A pressing portion, which is provided at the tip of the swing arm so as to be elastically movable back and forth, and constantly contacts the peripheral surface of the pawl; detecting means for detecting the advancing / retreating state of the pressing portion; The lifting device according to claim 1, further comprising control means for stopping the driving means in accordance with the input.