JPH0241982B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that protects the safety of workers who ascend and descend utility poles by preventing them from falling. The performance required for this type of safety device is to have the strength to withstand the impact load when stopping a fall, and not only to stop and hold a falling human body, but also to absorb and alleviate the impact load that the human body receives when stopping a fall. The Ministry of Labor's standards for safety belts require safety devices to be designed so that the impact load applied to the human body is 900 kgf or less, taking into account the safety limits of the human body against falling impact. Since this is stipulated, the device must have excellent cushioning properties.
In view of the current situation, the present invention provides a fall prevention device installed on utility poles, etc., which has a rigid structure up to a predetermined load, and when an impact load exceeding a predetermined value is applied, the upper fixing metal part deforms plastically to absorb and soften the impact. Its purpose is to provide.

Aspects of the invention will now be described in detail with reference to an embodiment illustrated in the accompanying drawings.

As shown in the figure, this embodiment consists of a main body A and a supporting member B, and the main body A is an approximate T having a crown part 15 and a leg part 16 by press working using a plate material.
A utility pole support piece is punched out in a letter shape, a notch 18 is provided at the center outer edge of the top piece 15, the edges on both sides of the notch 18 are bent to one side, and then welded to each other. 19 are provided at both ends of the top piece 15, respectively, and support member attachment holes 6, 6 are provided inside the pole band attachment holes 5, 5, and the leg piece 16 has a notch at the center of its tip. 20, guideline mounting holes 7, 7 are provided on both sides thereof, and a side wall portion 17 is formed by bending both sides of the leg portion 16 in the same direction as the utility pole support piece 15, leaving a bottom portion at the center in the longitudinal direction of the leg portion 16, and opposing side wall portions 17. , 17, the part that used to be the leg part 16 becomes the arm part 2, and the part that used to be the crown part 15 becomes the base part 1, and the base part 1 and the arm part 2 form an approximate L-shape. The side wall portions 17, 17 of the arm portion 2 are formed in a tapered shape that becomes narrower from the base portion 1 side toward the tip.

The supporting member B is made by cutting a bar material into a predetermined length as shown in Fig. 4, and forming a narrow diameter part 11 in the middle part of the bar material by press working or lathe work, which is thinner than other parts, and forming a small diameter part 11 in the middle part, which is thinner than other parts, and in both ends. In this example, a connecting hole 9 is formed in a bulging connecting portion, and the supporting member B is connected between the supporting member mounting hole 6 of the base 1 of the main body A and the guideline mounting hole 7 of the arm portion 2. The base 1 of the main body A, the arm 2, and the support member B form the upper fixing fitting of the present invention having a truss structure. Incidentally, when the distal end of the arm portion 2 and the distal end of the support member B are pivotally connected, the connecting fitting 8 of the guideline 13 is also pivotally connected.

To use the present invention, as shown in FIG. The upper fixing metal fitting is attached to a predetermined position on the electric pole by inserting and tightening the electric pole band to fix the electric pole band, and the upper end of the guideline 13 is attached to the connecting metal fitting 8 which is riveted together with the support member B to the guideline attachment hole 7 at the tip of the arm part 2. The lower end of the guideline is attached to the lower end of the guideline by a lower mounting bracket C separately attached to the lower part of the utility pole P. In this way, the upper fixing metal fitting for a fall prevention device of the present invention is permanently installed on a utility pole.

A worker who performs construction work on a utility pole carries a safety device 14 to the site and attaches the safety device 14 to the guideline 13. After that, the hook of the safety belt attached to the worker's body is attached to the safety device (not shown).
combine. When a worker moves up and down the utility pole in this state, the safety device 14 moves up and down on the guideline as the worker moves.

When a worker slips and falls while ascending or descending, the safety device 14 immediately grabs the guideline 13 to stop the worker and restrain the worker. At this time, a high impact load of around 1200 kgf is applied to these fall prevention devices, including the upper fixing bracket, and to the body of the worker. The upper fixing metal fitting for a fall prevention device of the present invention has a plastic design for the purpose of buffering this impact load.

Normally, a tension of about 200 kgf is applied to the guideline 13 by a lower retaining metal fitting. Under this load of around 200Kgf, the upper fixing bracket is still in the elastic range due to its truss structure, so it does not deform.
However, when a high impact load is applied to the tip of the arm part 2 of the upper fixing metal fitting when stopping the fall, the narrow diameter part 11 of the support member B that supports the arm part 2 breaks due to the tensile load, and then Due to its tapered shape, the arm portion 2 gradually curves and deforms from the tip, and this deformation absorbs and relieves the impact load. The waveform of the impact load measured at this time using an oscilloscope is
As shown in Figure 3, it can be held at around 600Kgf. The first conspicuous mountain-like waveform (600Kgf) is the load when the small diameter portion 11 of the support member B is cut, and the second gentle mountain-like waveform is due to the load when the arm portion 2 bends and deforms. It is a load. In this way, in the present invention, the impact load is absorbed and alleviated by using plastic design to convert the impact load energy into cutting of the support member B and deformation of the arm part 2, thereby prolonging the time it takes to stop the fall. This helps keep workers safer. Moreover, this buffering effect not only protects the worker but also relieves the impact load applied to the utility pole P itself, thereby preventing the utility pole from being cut or damaged.

Moreover, the main body A of the upper fixing metal fitting of the present invention is
Since it is integrally formed by press working, it is lightweight but reinforced by the side walls 17, 17, etc., and the utility pole support pieces 19, 19 of the base 1 prevent the utility pole from separating in the direction of the outer circumference. Because it is welded, it is both durable and economical.

In addition, the arm portion 2 of the main body A is formed in a tapered shape that becomes thinner from the base 1 side toward the tip, so when stopping an impact load, the deformation starts from the tip and gradually changes depending on the size of the load. The deformation moves toward the thicker side of the base 1, thereby preventing damage to the main body A itself and providing a smooth cushioning effect.

Fig. 5 shows a second embodiment of the support member B of the present invention, in which a bar cut to a predetermined size is used, and three holes are punched in series at both ends of the bar so that each side has a hole. This embodiment differs from the first embodiment in that the center hole of the joint fitting 10 pressed into a shape is fixed by welding or screwing after fitting, and the other two holes are used as connecting holes 9. However, other aspects and work effects are equal.

FIG. 6 shows a third embodiment of the support member B of the present invention, and shows the coupling fitting 1 used in the second embodiment.
This embodiment differs from the first and second embodiments in that a round ring made of the same material as the main body of the support member B is used for the portion corresponding to 0 and is welded, but the other working effects are the same.

FIG. 7 shows a second embodiment of the present invention, which differs from the first embodiment in that the arm portion 2 is provided obliquely upwardly protruding from the base portion 1. In this case, the arm portion 2 is deformed. By increasing the (exercise) range, you can gain buffer time by that amount,
Further, the dimensions of the support member B are also the same as in the first embodiment except that a shorter one can be used.

FIG. 9 shows a third embodiment of the present invention,
The guideline attachment hole 7 at the tip of the arm portion 2 provided in the first embodiment is used as a support member attachment hole 22 and a guideline coupling hole 23, and is made independent for each purpose, and the above-mentioned connecting fitting 8 is riveted. This differs from the first and second embodiments in that the assembly time and product weight are reduced, and the narrow diameter portion 11 of the support member B is provided within the base 1.
Other things are equal.

Furthermore, the conditions for plastic deformation during buffering according to the present invention can be easily adjusted by changing the thickness or material of the plate forming the main body A. In addition, the function of the support member B, that is, the arm portion 2
The ability to maintain the elastic range of the material can be easily adjusted by changing the cross-sectional area of the narrow diameter portion.

[Brief explanation of the drawing]

Fig. 1 is a front view showing the present invention attached to a telephone pole, Fig. 2 is an exploded view of the main body, Fig. 3 is a front view of the main body, Fig. 4 is a support member, and Fig. 5 is a view of the support member. Embodiment 2, FIG. 6 shows the third embodiment of the support member, and FIG.
The figure shows a second embodiment of the main body, FIG. 8 is a waveform diagram showing an oscillographic impact load value when the embodiment is used, and FIG. 9 shows a third embodiment of the main body. Symbols in the figure: 1 is the base, 2 is the arm, 5 is the utility pole band attachment hole, 6 is the support member attachment hole, 7 is the guideline attachment hole, 9 is the connection hole, 10 is the coupling metal fitting,
11 is a small diameter part, 12 is a mounting bolt, 13 is a guideline, 14 is a safety device, 15 is a top piece, 16 is a leg piece, 17 is a side wall, 18 and 20 are notches, 19 is a utility pole rest Piece 21 is a telephone pole band, 22
23 is a support member mounting hole, 23 is a guideline coupling hole,
24 is the confirmation window, A is the main body, B is the support member, C is the lower mounting bracket, and P is the utility pole.

Claims (1)

[Claims] 1. A main body A is formed by a base 1 and an arm 2 protruding from the lower part of the base 1, and the tip of the arm 2 in the main body A and the middle part of the base 1 are supported by a support member B. They are combined to form a truss structure, and when a downward impact load of more than a predetermined value is applied to the tip of the arm part 2, the support member B loses its support function and the arm part 2 curves downward to buffer the impact. An upper fixing bracket for a fall prevention device, characterized by: 2 The main body A is a press-molded product using a plate material, and when unfolded, it forms an approximate T-shape, and by bending the leg part 16 to one side, the base part 1 and the arm part 2 are formed. The upper fixing metal fitting for a fall prevention device according to claim 1, characterized in that it has an approximate L-shape. 3 The base 1 is bent to have a utility pole band attachment hole 5 in the opposing upper end and a support member attachment hole 6 in the middle, and the arm 2 has a tapered shape that becomes thinner from the base 1 toward the tip. The upper fixing metal fitting for a fall prevention device according to claim 1 or 2, characterized in that a guideline attachment hole 7 is bored in the tip. 4 Support member B is forged and has connecting holes 9 at both ends.
The supporting member B is rod-shaped and has a narrow diameter part 11 in the middle part, and when a tensile load of more than a predetermined value is applied to the support member B, the narrow diameter part 11 is damaged and loses its function. Range 1st, 2nd, or 3rd
Upper fixing bracket for fall arrest device as described in . 5. The support member B is made of a bar material, to which a coupling fitting 10 having a connecting hole 9 is fixed to both ends thereof, and a narrow diameter part 11 is provided in the middle part, which is thinner than other parts, and a predetermined shape is attached to the support member B. The upper fixation for a fall prevention device according to claim 1, 2, or 3, wherein the narrow diameter portion 11 is damaged and loses its function when a tensile load of the above amount is applied. Metal fittings.