RU2521438C2 - Spiral tension clamp - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: invention is related to electric engineering, and namely to spiral tension clamps intended for fixation of wires and cables of overhead transmission lines. The spiral tension clamp is made as spirals wound into a strand and consisting of at least two branched wound onto the wire or cable and forming in the middle part a U-shaped loop with an eye inserted into it and fixed through connecting elements to the line support equipped with a protector made as coiled wires or ribbon coils and mounted at the U-shaped loop side at a section of the wire or cable free from wound strands.

EFFECT: invention ensures reliable fixture of wires and cables to overhead transmission lines and excludes damage of wires and cables of the overhead transmission line within the whole period of its operation at minimum complication of the clamp manufacturing technology, increase of material consumption and labour costs for its installation.

3 cl, 2 dwg

Description

The present invention relates to the field of electric power, in particular to spiral tension clamps for securing wires and cables of overhead power lines.

Known spiral tension clamp for anchoring the wires of overhead power lines or cables overhead lines containing either wound on a wire or cable, or on a protector mounted on a wire or cable, a U-shaped strand of wire spirals, consisting of two branches and one the end ending with a fixing loop in which the thimble is embedded; the clamp has an additional U-shaped strand of wire spirals having the opposite direction of winding [Description of the RF patent No. 2291535 "Spiral tension clamp", H02G 7/02, filed October 12, 2005, published January 10, 2007].

 Also known is a close-in-construction tension clamp, consisting of two power strands with opposite winding directions, which can be mounted either directly on a wire or cable, or on a tread mounted on a wire or cable [Description to RF patent No. 2315408 "Spiral tension clamp", H02G 7/02, claimed August 30, 2006, published January 20, 2008].

These clamps are intended mainly for operation under very high loads (tens of tons), therefore, in addition to two power strands, they can also include a tread that is longer than the length of the power strands and is designed both to provide a given termination strength and to prevent damage wires under intense compressive loads. At the same time, due to the presence of two power strands with opposite winding directions, the phenomenon characteristic of spiral reinforcement does not occur: when the tensile load changes during operation, the wire rotates together with the clamp along the longitudinal axis of the wire. The indicated rotation can cause abrasion and deformation of the wires of the upper coil of the wire in the places of irregular contact of the wire with the U-shaped strand of wire spirals from the loop side with the thimble. Unfortunately, the construction of the clamps described is relatively complex and expensive; requires installers a certain skill when installing the clamps on the wire.

The closest technical solution to the proposed one is a spiral tension clamp for securing wires and cables of overhead power lines, made in the form of spirals, twisted into a strand consisting of at least two branches, wound on a wire or cable, and forming in the middle parts of the strand U-shaped loop with a thimble embedded in it, attached through connecting elements to the support of the overhead line [Description of the RF patent No. 2272346 “Spiral tension clamp”, H02G 7/02, filed July 29, 2004, published March 20, 2006, .].

This clamp has a simple and reliable design, but it does not solve the problem of eliminating damage to the wire or cable by the wires of the U-shaped clamp loop, which, when the tensile load changes, they begin (the clamp due to its elasticity is wound and wound off the wire) irregularly touch and move along the surface unprotected section of the wire at the point of contact with the branches of the power strand and damage the wire, up to the possible destruction of individual wires.

The technical result of the patented solution is to eliminate local damage to the wire or cable of the overhead power line under the clamp during the entire period of operation with minimal complication of the manufacture of the clamp and increase its material consumption and labor costs during its installation. The claimed technical result is achieved due to the design of the spiral tension clamp: “spiral tension clamp for securing the wires and cables of overhead power lines to the line supports, made in the form of spirals, twisted into a strand consisting of at least two branches wound onto a wire or cable, and forming in the middle part of the strand a U-shaped loop with a thimble embedded in it, attached through connecting elements to the line support, while it is additionally equipped with a tread made in the form of wire spi "rails, in the form of tape spirals or in the form of several strands of spirals and mounted on a section of wire or cable free from wound branches of the loop under the U-shaped loop, close to the wound branches of the loop." Tread spirals, wire, tape or strands of spirals (for example, wire spirals assembled into strands using glue or heat-shrink tubing) are wound onto a section of wire under a U-shaped loop close to the wound branches of the loop. During operation, when changing the magnitude of the tensile load, the wire rotates with the clamp, as well as small displacements of the clamp strands relative to the wire at the point of contact between the branches of the power strands and the wire, but twisted into a strand of the clamp spiral in the area where the shifts occur, contact not with the surface of the wire, but with the tread spirals, which ensures the safety of the wire. Since the length of the protected section of the wire is very small (the section of wire under the U-shaped loop with a thimble), and the tread shape is the simplest, the material consumption and labor costs for clamp production increase slightly; mounting the clamp is not complicated.

The clamp protector has a relatively short length, therefore, to prevent spontaneous displacement of the tread along the wire during strong initial bending of the wire coming out of the clamp, and also when the wire vibrates under the influence of the wind, “the tread with its end facing the span of the line goes under the stretch of the tension clamp on which they are wound on a wire or cable, up to 2 steps of tread spirals ”, so that the ends of the tread spirals are firmly clamped between the wire and the branches of the U-shaped loop.

The reliability of the adhesion of the tread to the wire, obviously, the greater the friction between them, which is achieved by the fact that "the inner surface of the spirals of the tread is covered with a layer of glue or a layer of glue with an abrasive."

The implementation of the wire spirals of the tread "of steel wire with a protective anticorrosive coating, or of aluminum wire, or of wire of a corrosion-resistant alloy or of plastic polymer material", as well as tape spirals of "metal corrosion-resistant or polymer tape" allows to increase the term clamping service, eliminating atmospheric corrosion. At the same time, regardless of the material and shape (individual wire spirals, strands of spirals, ribbons) of the tread, the tread performs its functions, eliminating local damage to the wire at the outlet of the tension clamp and increasing the life of the clamp. The choice of material and shape of the tread elements is determined based on the actual operating conditions of the clamp, taking into account the objectives of ensuring maximum strength (abrasion resistance) of the tread elements at a minimum cost.

The choice of the direction of winding of the spirals of the tread, which "coincides with the direction of winding the wires of the upper coil of wire or cable" or "opposite to the direction of winding of the wires of the upper coil of wire or cable" is determined by the design of the wire or cable itself (the material of the wires of the upper coil), the magnitude of the perceived loads, the direction of winding twisted into a strand of spirals forming a U-shaped loop.

The invention is illustrated by drawings, where figure 1 shows a General view of a set of spiral tension clamp made in accordance with the present invention; figure 2 is a General view of the clip mounted on the wire.

The inventive spiral tension clamp (figure 1), designed to secure the wires and cables of overhead power lines, consists of a strand of spirals having two branches 1 and 2 with a U-shaped loop 3 in its middle part, into which the thimble 4 is inserted. The clamp design additionally includes a tread 5 made in the form of individual wire spirals, strands of wire spirals or in the form of tape spirals. The direction of winding the spirals of the tread 5 may coincide with the direction of winding the upper winding of the wires of the wire (cable) on which it is installed, or be opposite to the direction of winding the wires of the wire (cable). The tread 5 is made in the form of wire spirals made of steel wire with a protective anti-corrosion coating, or of a wire of a corrosion-resistant alloy, for example, aluminum alloy, or of plastic polymer material, and tape spirals of the tread 5 can be made of corrosion-resistant metal or polymer tape. On the inner surface of the strands of wire spirals or tape spirals of the tread 5 can be applied a layer of glue with an abrasive.

Two options for clamp assembly are possible.

In the first case, the branches 1 and 2 of the clip strand are first wound on the wire 6, in which the thimble 4 is inserted into the U-shaped loop 3, after which the tread 5 is wound close to the wound branches of the clip strand under the loop 5. The thimble fits into the connecting fittings, on The wire is given a load. With an increase in the tensile load (the clamp is installed on an unloaded wire), the elastic part of the loop with an embedded thimble is pushed onto the end of the tread mounted from wire or tape spirals. Subsequently, during operation, when the magnitude of the tensile load changes, small movements of the clamp loop 3 relative to the wire 6 occur, but the spirals of the clamp twisted into a strand in the area where the motions occur are no longer in contact with the wire surface, but with the tread spirals, which ensures safety wires. The presence of an abrasive on the inner surface of the spirals of the tread 5 increases its adhesion to the surface of the wire 6 and ensures that the tread 5 does not move relative to the wire 6. The design of the spirals of the tread 5 made of corrosion-resistant materials ensures the clamp's resistance to weathering and increases its service life.

In the second case, on the wire 6, the protector 5 is initially mounted on the basis of the fact that part of it will be under the branches of the clamp, then the branches 1 and 2 of the clamp are mounted, in which loop 3 is embedded the thimble 4, while branches 1, 2 begin to wind on the end the tread 5 with the transition to the wire 6. In this embodiment, the tread 5 is more securely mounted on the wire 6 even in the absence of an adhesive layer with an abrasive on the inner surface of the tread 5. The clamp operation does not differ from that described in the previous embodiment.

The inventive spiral tension clamp favorably differs in that it does not adversely affect the wire or cable of the overhead power line: the wires of the U-shaped loop of the clamp strand do not touch the wire (cable) when the magnitude of the tensile load changes and, therefore, do not damage them. The clamp is simple in design, has minimal dimensions and light weight, and is also relatively cheap.

Claims (3)

1. A spiral tension clamp for securing wires and cables of overhead power lines to line supports made in the form of spirals twisted into a strand consisting of at least two branches wound on a wire or cable and forming U- in the middle part of the strand a shaped loop with a thimble embedded in it, attached through connecting elements to the line support, characterized in that it is provided with a tread made in the form of individual wire spirals or in the form of several strands of spirals made of steel wire with protection with a corrosion-resistant coating or from an aluminum alloy wire, or from a corrosion-resistant alloy wire, or from a plastic polymer material, or in the form of tape spirals made of aluminum metal or corrosion-resistant tape, or a polymer tape, while the tread is mounted on a section of wire or cable, free from wound branches of the loop, under the U-shaped loop that is close to the wound branches of the spiral and has a winding direction that is the same or opposite compared to the direction of winding portage upper helix wire. 2. The clamp according to claim 1, characterized in that the tread with its end facing the span of the line, goes under the section of the strands of the tension clamp, on which they are wound on a wire or cable for up to 2 steps of tread spirals. 3. The clamp according to claim 1 or 2, characterized in that an abrasive is applied to the surface of the spirals, strands of wire spirals or tape spirals of the tread.

Images