JP4321741B2 - Ladder lifting assist device safety device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lifting assist device for reducing a burden when a worker moves up and down a ladder attached to a steel tower or the like, for example, when a device that pulls a worker descends at a predetermined speed or more for some reason Further, the present invention relates to a safety device that detects this and stops the device.
[0002]
[Prior art]
A ladder raising / lowering assisting device that raises and lowers a traction device by meshing a motor or engine-driven gear with a rack rail provided so as to extend along the ladder is known (for example, JP-A-10-131655). . In such a conventional lift assist device, there is no safety device that detects this when the device descends at a predetermined speed or more for some reason and stops the device.
[0003]
[Problems to be solved by the invention]
Therefore, an object of the present invention is to provide a safety device for a ladder raising / lowering assisting device that detects and stops the apparatus when the apparatus descends at a predetermined speed or more for some reason.
[0004]
[Means for Solving the Problems]
In the present invention, in order to solve the above problem, the rack rail 31 is provided with a row of vertical openings 31b for meshing the teeth of the gear 5, and the traction device 2 is opposed to the row of openings 31b of the rack rail 31. The photoelectric sensor 18 for detecting the opening 31b is provided at a position where the opening 31b is detected, the opening detection signal from the photoelectric sensor 18 is received, and the lifting speed of the traction device 2 is calculated from the number of detection signals per predetermined time, A control device 19 that activates the stop mechanism 11 when it exceeds a certain speed is provided to constitute a safety device for the ladder lifting assist device 1.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings. 1 is a front view of the lifting assist device, FIG. 2 is a side view thereof, FIG. 3 is a plan view thereof, FIG. 4 is a front view of an emergency stop mechanism, FIG. 5 is a side view of the emergency stop mechanism, and FIG. FIG.
[0006]
In the figure, the rack rail 31 is laid in the vertical direction along a ladder (not shown). The rack rail 31 is a steel rectangular tube body having a vertical dividing groove 31a at the center of the front surface, and has openings 31b arranged at equal intervals in the vertical direction on the left and right side plates.
[0007]
The lifting / lowering assisting device 1 includes a traction device 2 and a traction band 3 connected thereto. The traction device 2 can be moved up and down by engaging the gear 5 with the rack rail 31 by driving the motor 4 with a battery power source. An operator wears the traction belt 3 and raises and lowers the ladder by himself / herself with the assistance of the traction force of the traction device 2. Sensors (not shown) are provided at the upper and lower portions of the apparatus, and the motor 4 is stopped by detecting stoppers provided at the upper and lower portions of the rack rail 3. The rack rail 3 may be provided with a fall-preventing moving piece that is connected to a safety belt. Even if there is this moving piece on the rack rail 3, the sensor also detects the moving piece and prevents it from getting on.
[0008]
The traction device 2 is assembled on the base 6. On the top and bottom of the center of the base 6, bearing plates 7 and 8 project so as to be inserted into the split groove 31 a of the rack rail 31. Guide rollers 9 and 10 that roll inside the rack rail 31 are attached to the bearing plates 7 and 8.
[0009]
As shown in FIGS. 4 to 6, the emergency stop mechanism 11 is provided on the bearing plate 7. A bracket plate 12 is fixed to the left and right side surfaces of the bearing plate 7, and a shaft 13 is rotatably supported by the bracket plate 12. A link plate 14 is fixed to the shaft 13 between the bracket plates 12, and a cam 15 is fixed to the outside of the bracket plates 12. A solenoid 17 is attached to the base 6 via an arm 16, and the tip of a shaft 17 a is pivotally attached to the link plate 14. The cam 15 faces the front side of the rack rail 31 through the opening 6 a of the base 6.
[0010]
Thus, when the shaft 17a of the solenoid 17 is pulled, the cam 15 rotates via the link plate 14 and the shaft 13, and the front end of the cam 15 engages with the front surface of the rack rail 31. The traction device 2 is stopped across the rack rail 31.
[0011]
A photoelectric sensor 18 for detecting abnormal lowering of the traction device 2 is mounted on the base 6 (FIGS. 3 and 6). The photoelectric sensor 18 is attached at a position where laser light is irradiated toward the side surface of the rack rail 31, detects the opening 31 a of the rack rail 31, and sends a detection signal to the control device 19. The control device 19 receives the opening detection signal from the photoelectric sensor 18, calculates the lifting speed of the traction device 2 from the number of detection signals per predetermined time, and when it exceeds a certain speed, the solenoid of the stop device 11. 17 is activated and the traction device 2 is stopped in an emergency.
[0012]
【The invention's effect】
As described above, in the present invention, the rack rail 31 is provided with the vertical row of openings 31 b for meshing the teeth of the gear 5, and the traction device 2 is opposed to the row of openings 31 b of the rack rail 31. In addition, the photoelectric sensor 18 for detecting the opening 31b is provided, the opening detection signal from the photoelectric sensor 18 is received, and the lifting speed of the traction device 2 is calculated from the number of detection signals per predetermined time. Since the safety device of the ladder raising / lowering auxiliary device 1 is configured by providing the control device 19 that activates the stop mechanism 11 when a certain speed is exceeded, the speed of the traction device 2 is reliably detected by the photoelectric sensor 18, and in the event of an abnormal fall, etc. The traction device 2 can be reliably stopped to ensure safety.
[Brief description of the drawings]
FIG. 1 is a front view of a lifting assist device.
FIG. 2 is a side view of the lifting assist device.
FIG. 3 is a plan view of the lifting assist device.
FIG. 4 is a front view of an emergency stop mechanism.
FIG. 5 is a side view of an emergency stop mechanism.
FIG. 6 is a plan view of an emergency stop mechanism.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Lifting assistance apparatus 2 Pulling apparatus 3 Pulling belt 4 Motor 5 Gear 6 Base 6a Opening 7 Bearing plate 8 Bearing plate 9 Guide roller 10 Guide roller 11 Emergency stop mechanism 12 Bracket plate 13 Shaft 14 Link plate 15 Cam 16 Arm 17 Solenoid 17a Shaft 18 Photoelectric sensor 19 Control device 31 Rack rail 31a Split groove 31b Opening

Claims (1)

A rack rail provided so as to extend along the ladder, emergency stop engaging Oite the lift assist device ladder for raising and lowering the traction device to engage the gear motor drive, the traction device for abnormal lowering the rack rails A safety device that is stopped by a mechanism ,
A vertical opening row of the rack rail meshing with the gear teeth ;
A photoelectric sensor that is provided at a position facing the opening row of the rack rail of the traction device and detects the opening;
A control device that receives the opening detection signal from the photoelectric sensor, calculates the lifting speed of the traction device from the number of detection signals per predetermined time, and activates the emergency stop mechanism when it exceeds a certain speed , provided to the safety device of the ladder lift assist apparatus according to claim Rukoto.

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