Alarm system for retractable fall arrest devices

Abstract

To provide an alarm device capable of informing a worker working at height that a retractable fall prevention device is not being used properly. [Solution] The alarm device 20 is a device attached to a rope 13 extending from a reel 12 of a retractable fall prevention device 10 and includes an inclination angle detection unit that detects the inclination angle, which is the angle of the longitudinal direction of the rope 13 with respect to the vertical direction, at least one alarm unit, and a control unit that controls the alarm unit. The control unit controls the alarm unit based on the magnitude relationship between the inclination angle detected by the inclination angle detection unit and a predetermined threshold value.

Description

[Technical field]

[0001] The present invention relates to a warning device that notifies workers working at height that a retractable fall arrest device is not being used properly. [Background technology]

[0002] Conventionally, when working at height, a retractable fall arrest device 10 shown in Figures 6 and 7 has been used. The retractable fall arrest device 10 is also called a safety block.

[0003] The retractable fall arrest device 10 includes an attachment hook 11 attached to a structure 100 located higher than a worker W at a height, a reel 12 connected to the lower end of the attachment hook 11, a rope 13 extending from the reel 12, and a D-ring attachment hook 14 connected to the lower end (tip) of the rope 13. The D-ring attachment hook 14 is attached to a full harness worn by the worker W at a height. When the worker W at a height accidentally falls from a scaffold 101, the rope 13 is reeled out from the reel 12 until the automatic lock is activated.

[0004] It is said that the worker W at a height must work in a position close to directly below the reel 12 (more precisely, in a position where the angle θ of the longitudinal direction of the rope 13 with respect to the vertical line P does not exceed 30 degrees) in order to prevent the worker W from colliding with another structure in the event of a fall (see, for example, Non-Patent Document 1). For this reason, at work sites where work is carried out at height, the "range not exceeding 30 degrees" is indicated on the scaffolding 101 with colored tape. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] "Industrial Safety Institute Technical Guideline Safety Belt Usage Guideline NIIS-TR-No.37(2004)", National Institute of Industrial Safety and Health (National Institute of Occupational Safety and Health, Independent Administrative Institution, Japan Occupational Health and Safety Organization), p.17-18 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when there are multiple mounting positions for the mounting hook 11, it is very difficult to display the "range not exceeding 30 degrees" corresponding to each mounting position on the scaffold 101. Also, the worker W at a height may unintentionally deviate from the "range not exceeding 30 degrees" displayed on the scaffold 101.

[0007] The present invention has been made in consideration of the above-mentioned circumstances, and its objective is to provide an alarm device that can notify a worker working at height that a retractable fall arrest device is not being used properly. [Means for solving the problem]

[0008] In order to solve the above problems, the alarm device of the present invention is a device that is attached to a rope extending from a reel of a retractable fall prevention device, and is equipped with an inclination angle detection unit that detects the inclination angle, which is the longitudinal angle of the rope relative to the vertical direction, at least one alarm unit, and a control unit that controls the alarm unit, and the control unit is configured to control the alarm unit based on the magnitude relationship between the inclination angle detected by the inclination angle detection unit and a predetermined threshold value.

[0009] The thresholds may include a first threshold and a second threshold (wherein the second threshold is greater than the first threshold). In this case, the control unit may set the alarm unit to a stopped state when the tilt angle does not exceed the first threshold, set the alarm unit to a first operating state when the tilt angle is between the first threshold and the second threshold, and set the alarm unit to a second operating state different from the first operating state when the tilt angle exceeds the second threshold.

[0010] The alarm unit includes, for example, a light alarm unit and an audio alarm unit.

[0011] The second threshold is, for example, 30 degrees. Effect of the Invention

[0012] According to the present invention, it is possible to provide an alarm device that can notify a worker working at height that a retractable fall arrest device is not being used properly. [Brief description of the drawings]

[0013] [Figure 1] 1A and 1B are diagrams showing a retractable fall prevention device equipped with a warning device according to an embodiment of the present invention, in which (A) is a front view and (B) is a right side view. [Diagram 2] 1 is a block diagram showing a schematic configuration of an alarm device according to an embodiment of the present invention; [Diagram 3] FIG. 1 shows the use of an alarm device according to an embodiment of the present invention, where (A) is a diagram showing the state in which the inclination angle, which is the angle of the longitudinal direction of the rope relative to the vertical direction, is 0 degrees, (B) is a diagram showing the state in which the inclination angle is +30 degrees, and (C) is a diagram showing the state in which the inclination angle is -30 degrees. [Figure 4] 5 is a diagram showing the control of the alarm unit performed by the control unit in the alarm device according to the embodiment of the present invention; FIG. [Diagram 5] 10A and 10B are diagrams showing control of an alarm unit performed by a control unit in an alarm device according to a modified example of the present invention. [Figure 6] 1A and 1B are diagrams showing a conventional retractable fall arrest device, in which (A) is a front view and (B) is a right side view. [Figure 7] 1A and 1B are diagrams relating to problems associated with conventional retractable fall prevention devices. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an alarm device according to the present invention will now be described with reference to the accompanying drawings.

[0015] [Example] As shown in Fig. 1, an alarm device 20 according to an embodiment of the present invention is used by being attached to an existing retractable fall arrest device 10. As described above, the retractable fall arrest device 10 includes an attachment hook 11 that is attached to a structure 100 (see Fig. 3) that is located higher than a worker at height, a reel 12 connected to the lower end of the attachment hook 11, a belt-like rope 13 extending from the reel 12, and a D-ring attachment hook 14 connected to the lower end (tip) of the rope 13.

[0016] The alarm device 20 is attached to the rope 13 at a position near the lower end thereof by a suitable fastener 30.

[0017] 2, the alarm device 20 includes a tilt angle detection unit 21, a memory unit 22, a control unit 23, an optical alarm unit 24, an audio alarm unit 25, and a power supply unit 26. These are housed in a box-shaped housing.

[0018] The inclination angle detection unit 21 is composed of a sensor that outputs a signal related to its own inclination with respect to the vertical direction. In the state shown in Fig. 3(A) (i.e., the state where the inclination angle θ, which is the angle of the longitudinal direction of the rope 13 with respect to the vertical direction, is 0 degrees), the inclination angle detection unit 21 outputs a signal corresponding to 0 degrees, in the state shown in Fig. 3(B) (i.e., the state where the inclination angle θ is +30 degrees), and in the state shown in Fig. 3(C) (i.e., the state where the inclination angle θ is -30 degrees), it outputs a signal corresponding to -30 degrees.

[0019] The storage unit 22 is made of a non-volatile memory. The storage unit 22 stores a predetermined threshold value. In this embodiment, the threshold value is "30 degrees."

[0020] The optical alarm unit 24 is made up of an LED.

[0021] The acoustic alarm unit 25 comprises a buzzer.

[0022] The power supply unit 26 is composed of a non-rechargeable dry cell, a button cell, or a rechargeable lithium-ion battery. The power supply unit 26 supplies the necessary power to each component of the alarm device 20.

[0023] The control unit 23 is composed of a microcontroller (MCU, Micro Controller Unit). The control unit 23 controls the two alarm units 24 and 25 based on the magnitude relationship between the absolute value |θ| of the tilt angle θ detected by the tilt angle detection unit 21 and a threshold value stored in the storage unit 22.

[0024] Specifically, the control unit 23 stops the optical alarm unit 24 when |θ| does not exceed the threshold value of 30 degrees, and activates the optical alarm unit 24 when |θ| exceeds 30 degrees (see FIG. 4). In this embodiment, the optical alarm unit 24 that is activated turns on in red, but this is merely an example.

[0025] Furthermore, the control unit 23 stops the acoustic alarm unit 25 when |θ| does not exceed 30 degrees, and activates the acoustic alarm unit 25 when |θ| exceeds 30 degrees (see FIG. 4). In this embodiment, the acoustic alarm unit 25 that is activated continuously outputs a buzzer sound at a volume that will not be drowned out by the noise at the work site, but this is merely one example.

[0026] In this way, the warning device 20 according to this embodiment can inform the worker at height by light and sound that he is too far from directly below the reel 12 and that there is a high possibility that he will fall into a pendulum state if he continues in this position. In other words, the warning device 20 can inform the worker at height that the retractable fall arrest device 10 is not being used properly.

[0027] [Variations] Although the embodiment of the alarm device according to the present invention has been described above, the present invention is not limited thereto.

[0028] For example, the storage unit 22 may store "20 degrees" as the first threshold and "30 degrees" as the second threshold. In this case, the control unit 23 may stop the optical alarm unit 24 when |θ| does not exceed 20 degrees, may set the optical alarm unit 24 to a first operating state (flashing red at a predetermined cycle) when |θ| is between 20 degrees and 30 degrees, and may set the optical alarm unit 24 to a second operating state (illuminating red) when |θ| exceeds 30 degrees (see FIG. 5). The control unit 23 may also stop the acoustic alarm unit 25 when |θ| does not exceed 20 degrees, may set the acoustic alarm unit 25 to a first operating state (intermittently outputting a buzzer sound) when |θ| is between 20 degrees and 30 degrees, and may set the acoustic alarm unit 25 to a second operating state (continuously outputting a buzzer sound) when |θ| exceeds 30 degrees (see FIG. 5). This configuration can notify a worker at height that the use of the retractable fall arrest device 10 is becoming inappropriate.

[0029] The alarm device 20 may include either one of the light alarm unit 24 and the sound alarm unit 25 as an alarm unit, or may further include another alarm unit (for example, a vibration alarm unit). In other words, the alarm device 20 may include at least one arbitrary alarm unit.

[0030] The alarm device 20 may be attached to the rope 13 by means other than the tie 30. For example, the alarm device 20 may be attached to the rope 13 by adhesive.

[0031] The threshold value, the first threshold value, and the second threshold value stored in the storage unit 22 may be changeable from the outside.

[0032] The retractable fall arrest device to which the alarm device 20 is attached is not limited to the retractable fall arrest device 10 shown in Fig. 1. For example, the alarm device 20 may be attached to a retractable fall arrest device of a type that has a metal fitting such as a carabiner and an attachment rope instead of the attachment hook 11, or may be attached to a retractable fall arrest device of a type that has a rope-like bail 13 instead of the belt-like bail 13. The alarm device 20 may also be attached to a retractable fall arrest device of a type that has a shock absorber. [Explanation of symbols]

[0033] 10 Retractable fall arrest device 11 Mounting hook 12 Winder 13 ropes 14 D-ring mounting hook 20 Alarm device 21 Tilt angle detection unit 22 Memory section 23 Control Unit 24 Optical alarm unit 25 Acoustic alarm unit 26 Power supply section

Claims

1. A warning device that is attached to a rope extending from a reel of a retractable fall arrest device, An inclination angle detection unit that detects an inclination angle, which is an angle of the longitudinal direction of the rope with respect to a vertical direction; At least one alarm unit; A control unit for controlling the alarm unit; Equipped with The control unit controls the warning unit based on a magnitude relationship between the tilt angle detected by the tilt angle detection unit and a predetermined threshold value.

1. An alarm device comprising:

2. The threshold value includes a first threshold value and a second threshold value (wherein the second threshold value is greater than the first threshold value), The control unit sets the alarm unit to a stopped state when the tilt angle does not exceed the first threshold, sets the alarm unit to a first operating state when the tilt angle is between the first threshold and the second threshold, and sets the alarm unit to a second operating state different from the first operating state when the tilt angle exceeds the second threshold.

2. The alarm device according to claim 1.

3. The alarm unit includes a light alarm unit and an audio alarm unit.

3. The alarm device according to claim 2.

4. The second threshold is 30 degrees.

4. The alarm device according to claim 3.

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