JPH0343849B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] This invention relates to a free center suspension clamp for overhead lines.

[Conventional technology]

An example of a conventional free center suspension clamp for overhead lines of this type is shown in FIG.

In the figure, reference numeral 1 denotes an overhead wire holder, 3, which is provided with a mounting surface 2 whose longitudinal direction and cross-section in a direction perpendicular to the longitudinal direction are formed in an arc shape, in order to suspend the overhead wire. 5 is an overhead wire holding device having a holding surface 4 that cooperates with the above-mentioned mounting surface 2 to hold the overhead wire; 5 is a strap provided on both sides of the overhead wire holder 1 so as to be tiltable; and 6 is an overhead wire holding device. This is a mounting bolt that tightens the overhead wire holding device 3 to the wire receiving metal fitting 1 and tightens and fixes the overhead wire inserted between the mounting surface 2 and the holding surface 4.

The conventional free center type suspension clamp for overhead lines is constructed as described above, so when installing an overhead line, the overhead line is passed between the straps 5, and then the overhead line holding device 3 is attached to the overhead line receiver. Metal fittings 1
At the same time, the overhead wire holding tool 3 was tightened and fixed to the overhead wire receiving metal fitting 1 using the mounting bolts 6.

[Problem that the invention seeks to solve]

The conventional free center type suspension clamp for overhead lines is constructed as described above, and the mounting bolt 6
Since the overhead wire is tightened and fixed to the overhead wire free center type suspension clamp only by tightening force via the overhead wire holding device 3, it is difficult to tighten uniformly with a predetermined tightening pressure. Even after tightening, the tightening force decreases over time due to creep in the bolts, wires, and various parts of the clamp.
In order to anticipate this decrease, excessive tightening force is required, and furthermore, if the tightening is strong, the external force applied to the overhead line in the track direction is directly applied to the fixed parts such as steel towers, and furthermore, this excessive tightening Depending on the force, the overhead wires may be deformed or their strength may be reduced.

This invention was made in order to solve the above-mentioned problems. It can be tightened uniformly with a predetermined tightening pressure, and even if various parts creep, the tightening force does not decrease excessively over time. The present invention aims to provide a free center type suspension clamp for overhead wires that does not require any additional tightening force and is flexible against the action of large external forces.

[Means for solving problems]

The free center type suspension clamp for overhead wires according to the present invention has a holding device having a holding surface having an arcuate cross section in the right angle direction that presses down the overhead wire in cooperation with the mounting surface of the overhead wire receiving fitting on the lower surface. a wire holding device; a shaft portion having an engaging portion at one end that engages with the upper end of the overhead wire holding device; and a holding portion that holds the elastic member in a compressed state at the other end; The elastic member fitted into the section engages with the opposite side of the above-mentioned elastic member from the overhead wire holding device side, and a preset pressure is applied to the elastic member, and one end of the mounting bolt is engaged. The cap is provided with an engaging portion.

[Effect]

Since the free center suspension clamp for overhead lines according to the present invention is constructed as described above,
The overhead wire is held between the mounting surface and the holding surface, and is pressed and fixed under constant pressure by the overhead wire holding device which receives the pressing force of the elastic member. Note that this constant pressure is adjusted by the tightening force of the elastic member prior to assembly. Note that this holding portion is released from the shaft portion after assembly.

〔Example〕

The present invention will be explained below based on the drawings showing one embodiment thereof.

In FIGS. 1, 2 and 3, reference numeral 1
Reference numeral 1 denotes an overhead wire receiving metal fitting, which has substantially the same structure as the conventional device, and is also provided with a similar strap 12.

Reference numeral 13 is a presser device, and the presser device 13
As shown in FIG. 3, the overhead wire holding tool 14 and
It is composed of a shaft portion 15, an elastic member 16, and a cap 17, and the holding device 13 is attached to the mounting bolt 1.
8 is attached to the overhead wire holder 11.

The overhead wire holding device 14 has a holding surface 19 formed in an arc shape on its lower surface, and the overhead wire holding device 1
In cooperation with the overhead wire mounting surface 20 of No. 1, the overhead wire is clamped and pressed to tighten. Further, a screw hole 21, which is an engaging portion that engages with the shaft portion, is formed on the upper surface.

The shaft portion 15 has a threaded portion 22 formed at its lower end, which is an engagement portion that screws into the screw hole 21 of the overhead wire holding device 14, and a washer 23 provided at the upper end of the threaded portion 22. In addition, a nut threaded part 25 is formed at the upper end, into which a nut 24, which is a holding part shown in FIG. 4, is screwed. A grip portion 26 is provided.

The elastic member, for example, the disk spring 16, is one piece or a combination of two or more pieces, and the washer 23 of the shaft portion 15
A washer 23 is fitted on the shaft portion 15 between the nut 24 and the nut 24, and a washer 23 is also provided on the upper part.

The cap 17 has a hole 2 in its top portion through which a nut 24 screwed into the nut threaded portion 25 of the shaft portion 15 passes.
7 is provided, and its shoulder portion 28 presses the disc spring 16 via the washer 23, and the hole through which the mounting bolt 18 passes is formed so that the head of the mounting bolt 18 passes through in one direction. It can be freely rotated, and when turned at right angles, the above-mentioned head will turn into cap 1.
7.

The nut 24 is used to apply a tightening force to the disc spring 16 in advance as shown in FIG. 4 in order to apply a predetermined pressing force to the overhead wire holding device 14. It is removed when assembled to the wire receiving fitting 11.

The embodiment of the free center type suspension clamp for overhead lines according to the present invention is constructed as described above, and the procedure for attaching it to the overhead line will be described next.

(1) Before installation, the washer 23, disc spring 16, and washer 23 are fastened to the shaft portion 15 by the nut 24 with a predetermined tightening force so that a predetermined pressing force is applied to the overhead wire holding tool 14. It is assembled by tightening it. This assembled shaft part 15
and a disc spring 16 are screwed into the overhead wire holding device 14 and attached by screwing the entire length of the screw hole 21 or the entire length of the threaded portion 25, and the cap 17 is covered and placed on the overhead wire holding device 11. is placed on the overhead line holder 1 with the mounting bolt 18.
It is attached to 1.

(2) To attach the overhead line clamp of the present invention to an overhead line from the state of (1) above, first loosen the mounting bolt 18, rotate it approximately 90 degrees, and then tighten the cap 17.
can be removed from the mounting bolt 18, and the holding device 13 is pulled out. In this case, naturally, the overhead wire holding device 14 is also pulled out at the same time by screwing the screw hole 21 and the screw portion 22 together.

(3) After placing the overhead line on the mounting surface 20 of the overhead line holder 11, the free center type suspension clamp for the overhead line is suspended using the strap 12.

(4) Next, after placing the holding device 13 on the overhead wire holder 11, insert the mounting bolt 18 into the cap 17, turn it, and tighten it to fix it.

(5) Rotate the nut 24 screwed into the nut threaded portion 25 of the shaft portion 15 in the loosening direction. Due to this rotation, the tension of the disc spring 16 is applied to the nut 24, so at first, there is no mutual rotation between the nut 24 and the threaded part 25 for the nut, and the overhead wire holding tool 14 screw holes 21 and shaft part 1
5, and the shaft portion 15 having the disc spring 16 moves in the direction of removal.

(6) By further rotating the nut 24, the washer 23 on the disc spring 16 is attached to the shoulder 2 of the cap 17.
8, and subsequent rotation of the nut 24 transfers the tension of the disc spring 16 that was applied to the nut 24 from the nut 24 to the mounting bolt 18 via the cap 17, and finally the full tension is applied to the mounting bolt 18. Since the load is transferred to the bolt, the load on the nut is also zero.

(7) When the tension load of the disc spring 16 on the nut 24 becomes zero, the nut 24 will idle, so the nut 24 can be pulled out. In this state,
The full tension of the disc spring 16 is applied to the overhead wire holding device 14 through the threaded portion 22 and the threaded hole 21,
The overhead wire is tightened and fixed between the mounting surface 20 and the holding surface 19.

The above is a procedure for attaching a free center type suspension clamp for an overhead line to an overhead line, but conversely, when removing an overhead line, the above procedure can be reversed.

Since this embodiment is constructed, assembled, and installed as described above, the clamping force of the overhead wire is
This is the tightening force of the disc spring 16, and the tightening force can always be made uniform.

In the above embodiment, a disc spring was used as the elastic member, but the elastic member is not limited to this, and any elastic member may be used. Also, the engagement between the cap and the mounting bolt, and the shape and configuration of the mounting bolt are also as described above. Further, the washer on the threaded portion may also be built into the shaft portion.

In addition, this free center suspension clamp for overhead lines can be used for overhead lines in general, but
In particular, it can be used for optical fiber composite overhead ground wires in that it does not apply excessive tightening force, does not cause damage to overhead wires, and can prevent transmission loss.

Further, in the above embodiment, the overhead wire holding device 14 and the shaft portion 15 are engaged with each other by a screw, but the screw may not be provided and the shaft portion 15 may be simply abutted. Although the holding portion is formed by the nut threaded portion 25 and the nut 24, the preset pressure may be applied by a cam or a hook instead of screw engagement.

〔Effect of the invention〕

According to this invention, the electric wire is tightened by the elastic member configured so that the tension is set in advance, and the elastic member eliminates the backlash in each part and the clearance required during installation. Since the preset force is automatically absorbed before it is released, the clamping force on the overhead wire is uniform and does not vary, and the decrease in clamping force over time due to creep of the overhead wire or various parts of the clamp is small. In addition, there is no need to set the initial tightening force excessively, and it can be set to a small value.Therefore, the design strength of each part can be reduced, resulting in a compact structure. Even in this case, since only one nut, cam, and hook are required, the work is simple and easy, and there is an effect that a free center type suspension clamp for an overhead line can be obtained in which the tightening force does not change due to the work.

In addition, since the clamping force of the overhead wire is constant,
The gripping force of the overhead wire, which is proportional to the clamping force, is also stable, so it is possible to prevent support structures such as steel towers from being damaged due to slipping of the overhead wire even under abnormal loads due to snow accumulation, etc. It also has the effect of providing a free center suspension clamp for overhead lines.

[Brief explanation of drawings]

FIG. 1 is a partially sectional plan view of an embodiment of the present invention, FIG. 2 is a partially sectional front view of FIG. 1, FIG. 3 is a sectional view taken along the - line in FIG. FIG. 1 is a front view of the elastic member in a pre-assembled state, and FIG. 5 is a front view of a conventional overhead line suspension clamp. 11... Overhead wire holder, 14... Overhead wire holding tool, 15... Shaft portion, 16... Elastic member (disc spring),
17...Cap, 18...Mounting bolt, 19...
... Pressing surface, 20 ... Placement surface, 21 ... Engagement part (screw hole), 22 ... Engagement part (thread part), 23 ... Washer, 24 ... Holding part (nut), 25 ... Holding part (threaded part for nut), 27...hole, 28...shoulder part.

Claims (1)

[Scope of Claims] 1. A free center type vertical clamp in which an overhead wire gripping device for gripping an overhead wire by an overhead wire holder and an overhead wire holding device is rotatably supported on a strap by a pivot, as described above. a cap provided above the overhead wire holding device and having an opening at the center of the top; an elastic member whose upper and lower sides engage with the inner shoulder of the cap and the overhead wire holding device; and the above overhead wire receiving metal fitting. It is characterized by comprising a mounting bolt that interconnects the cap and the cap, and a shaft portion whose lower end engages with the overhead wire holding device and which passes through the elastic member and also through the central opening of the cap. Free center suspension clamp for overhead lines. 2. The engagement between the lower end of the shaft and the overhead wire holder is achieved by a female thread provided on the overhead wire holder and a male thread provided at the lower end of the shaft that is screwed into the female thread. A free center type suspension clamp for an overhead line according to claim 1, wherein 3. The free center type suspension clamp for overhead wires according to claim 1 or 2, wherein the shaft portion has a nut threaded portion formed at its upper end into which a nut is screwed.