GB2136218A - Cable cleat - Google Patents

Abstract

A cleat for use in the installation of a pressure-sensitive electric cable having at least two spaced conductors, the cleat comprising a cable-receiving guideway 12 having a longitudinal axis smoothly curved in one plane and an inner radius of curvature R which is large enough to prevent substantial transverse movement of the conductors relative to one another when the cable is positioned in the guideway. <IMAGE>

Description

SPECIFICATION Cable cleat This invention relates to cleats for use in the installation of electric cables, pipes, or other flexible elongate members, and especially, though not exclusively, for use in the installation of pressure sensitive electric cables.

Pressure sensitive cables usually comprise two spaced conductors which, when the cable is subjected to a pressure above a predetermined level (for example by compressing, bending or pulling) move towards one another and either electrically connect with one another, or alter the resistance value between one another, either of which is detected by suitable circuitry connected to the conductors. A coaxial version of this type of cable is described in UK Patent No. 1 509031.

Problems can arise when installing this type of cable because if the cable is bent through an angle having too small a radius of curvature the movement of the conductors may accidentally actuate the circuitry.

According to the present invention we provide, for use in the installation of an electric cable having at least two spaced conductors, a cleat comprising a cable-receiving guideway having a longitudinal axis smoothly curved in one plane and an inner radius of curvature which is large enough to prevent substantial transverse movement of the conductors relative to one another when the cable is positioned in the guideway.

Preferably the cable-receiving guideway is substantially enclosed. In this case, the cleat preferably comprises two separately formed parts each defining substantially half the guideway, which parts mate along a plane bisecting the curved longitudinal axis of the guideway. In this arrangement, the cable can be positioned in the half of the guideway in one part of the cleat before the other part of the cleat is fastened to it.

Alternatively the cleat may comprise three or more separately formed parts.

Where the cleat comprises two or more parts, preferably the parts are fastened together by at least one nut and bolt. Preferably the nut(s) and bolt(s) are also used to secure the cleat to a support (e.g. a cable tray).

Preferably the guideway has a substantially circular transverse cross-section, and preferably, in this case, its diameter is substantially identical to the diameter of the cable to be installed.

Where the cable-receiving guideway is not substantially enclosed, the cable may be held in position in the guideway by one or more fingers which extend across the guideway.

The guideway preferably curves through an angle of 900.

The cleat may be made from any suitable material, for example an aluminium alloy or gunmetal.

The invention is further illustrated, by way of example, by the accompanying drawings in which:~ Figure 1 is a partially exposed side view of a pressure sensitive electric cable; and Figures 2 and 3 are each side and crosssectiona! views of each part of a preferred two part cleat in accordance with the invention.

Referring to Figure 1, the pressure sensitive electric cable 1 comprises a cnre 2, an inner conductor 3, a conductive plastics layer 4 over the inner conductor 5 separated from the first layer 4 by a spacer thread 6, an outer conductor 7 and a plastics sheath 8. If the cable 1 is compressed or bent the conductors 3, 7 electrically connect with each other through the conductive layers 4, 5.

The cleat 9 shown in Figures 2 and 3 comprises two parts 10, 1 1 each defining one half of a guideway 12 for receiving the cable 1, the parts 10, 1 1 mating along a plane bisecting the curved longitudinal axis of the guideway 12. The guideway 12 has a longitudinal axis which is smoothly curved in one plane and an inner radius of curvature R which is large enough to prevent substantial transverse movement of the conductors 3, 7 relative to one another. The two parts 10, 1 1 are secured together by nuts and bolts (not shown) using bolt holes 13. On assembly, the guideway is substantially enclosed.

1. A cable for use in the installation of an electric cable having at least two spaced conductors, said cleat comprising a cablereceiving guideway having a longitudinal axis smoothly curved in one plane and an inner radius of curvature which is large enough to prevent substantial transverse movement of the conductors relative to one another when the cable is positioned in the guideway.

2. A cleat as claimed in Claim 1, wherein the cable-receiving guideway is substantially enclosed.

3. A cleat as claimed in Claim 2, wherein said cleat comprises two separately formed parts each defining substantially half the guideway, which parts mate along a plane bisecting the curved longitudinal axis of the guideway.

4. A cleat as claimed in Claim 3, wherein the parts are fastened together by at least one nut and bolt.

5. A cleat as claimed in any one of the preceding Claims, wherein the guideway has a substantially circular transverse cross-section.

6. A cleat substantially as hereinbefore defined with reference to, and as shown in, Figures 2 and 3 of the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Cable cleat This invention relates to cleats for use in the installation of electric cables, pipes, or other flexible elongate members, and especially, though not exclusively, for use in the installation of pressure sensitive electric cables. Pressure sensitive cables usually comprise two spaced conductors which, when the cable is subjected to a pressure above a predetermined level (for example by compressing, bending or pulling) move towards one another and either electrically connect with one another, or alter the resistance value between one another, either of which is detected by suitable circuitry connected to the conductors. A coaxial version of this type of cable is described in UK Patent No. 1 509031. Problems can arise when installing this type of cable because if the cable is bent through an angle having too small a radius of curvature the movement of the conductors may accidentally actuate the circuitry. According to the present invention we provide, for use in the installation of an electric cable having at least two spaced conductors, a cleat comprising a cable-receiving guideway having a longitudinal axis smoothly curved in one plane and an inner radius of curvature which is large enough to prevent substantial transverse movement of the conductors relative to one another when the cable is positioned in the guideway. Preferably the cable-receiving guideway is substantially enclosed. In this case, the cleat preferably comprises two separately formed parts each defining substantially half the guideway, which parts mate along a plane bisecting the curved longitudinal axis of the guideway. In this arrangement, the cable can be positioned in the half of the guideway in one part of the cleat before the other part of the cleat is fastened to it. Alternatively the cleat may comprise three or more separately formed parts. Where the cleat comprises two or more parts, preferably the parts are fastened together by at least one nut and bolt. Preferably the nut(s) and bolt(s) are also used to secure the cleat to a support (e.g. a cable tray). Preferably the guideway has a substantially circular transverse cross-section, and preferably, in this case, its diameter is substantially identical to the diameter of the cable to be installed. Where the cable-receiving guideway is not substantially enclosed, the cable may be held in position in the guideway by one or more fingers which extend across the guideway. The guideway preferably curves through an angle of 900. The cleat may be made from any suitable material, for example an aluminium alloy or gunmetal. The invention is further illustrated, by way of example, by the accompanying drawings in which:~ Figure 1 is a partially exposed side view of a pressure sensitive electric cable; and Figures 2 and 3 are each side and crosssectiona! views of each part of a preferred two part cleat in accordance with the invention. Referring to Figure 1, the pressure sensitive electric cable 1 comprises a cnre 2, an inner conductor 3, a conductive plastics layer 4 over the inner conductor 5 separated from the first layer 4 by a spacer thread 6, an outer conductor 7 and a plastics sheath 8. If the cable 1 is compressed or bent the conductors 3, 7 electrically connect with each other through the conductive layers 4, 5. The cleat 9 shown in Figures 2 and 3 comprises two parts 10, 1 1 each defining one half of a guideway 12 for receiving the cable 1, the parts 10, 1 1 mating along a plane bisecting the curved longitudinal axis of the guideway 12. The guideway 12 has a longitudinal axis which is smoothly curved in one plane and an inner radius of curvature R which is large enough to prevent substantial transverse movement of the conductors 3, 7 relative to one another. The two parts 10, 1 1 are secured together by nuts and bolts (not shown) using bolt holes 13. On assembly, the guideway is substantially enclosed. CLAIMS

1. A cable for use in the installation of an electric cable having at least two spaced conductors, said cleat comprising a cablereceiving guideway having a longitudinal axis smoothly curved in one plane and an inner radius of curvature which is large enough to prevent substantial transverse movement of the conductors relative to one another when the cable is positioned in the guideway.

2. A cleat as claimed in Claim 1, wherein the cable-receiving guideway is substantially enclosed.

3. A cleat as claimed in Claim 2, wherein said cleat comprises two separately formed parts each defining substantially half the guideway, which parts mate along a plane bisecting the curved longitudinal axis of the guideway.

4. A cleat as claimed in Claim 3, wherein the parts are fastened together by at least one nut and bolt.

5. A cleat as claimed in any one of the preceding Claims, wherein the guideway has a substantially circular transverse cross-section.

6. A cleat substantially as hereinbefore defined with reference to, and as shown in, Figures 2 and 3 of the accompanying drawings.