GB1601531A

GB1601531A - Insulator

Info

Publication number: GB1601531A
Application number: GB2140678A
Authority: GB
Original assignee: BLIQUY M C DE
Current assignee: BLIQUY M C DE
Priority date: 1978-05-23
Filing date: 1978-05-23
Publication date: 1981-10-28

Description

(54) INSULATOR (71) I, MICHAEL CHRISTOFF DE BLIQUY, of South African Nationality, of 2 Lowndesgate East, Illovo, Johannesburg, Transvaal Province, Republic of South Africa, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to an insulator, particularly an insulator used for suspending high voltage power lines from pylons.

Such insulators normally comprise a capped disc of porcelain or glass, and a bell formation and a pin. The bell formation is fitted above and around the cap of the capped disc. One end of the pin is located in the cap of the capped disc to extend downwardly and the other end of the pin has a thickened region which fits into a locating formation in the bell formation of a succeeding insulator. In this manner, a number of insulators are connected together one below the other. The insulators are subjected to high mechanical loading and vibrations in use and, consequently, the bell formation and its locating formation must be strong. Heavy cast or forged bell formations have been used in the past but they are expensive and cumbersome to transport. It is an object of this invention to offer a solution to this problem.

According to the invention there is provided an insulator consisting of a capped disc, a pin secured axially to the disc and projecting downwardly from it, and means for connecting the insulator to a second, identical insulator, such means consisting of a bell formation having a body surrounding and secured to the cap of the disc, a shank adapted to receive the projecting pin of the second insulator, and means to anchor the pin in the shank.

The bell formation for the insulator may be formed by expanding or reducing the diameter of piping over a portion of its length.

Thus relatively small diameter piping can be expanded or relatively large diameter piping can have its diameter reduced over a portion of its length.

The expansion of the piping may be done by inserting a mandrel a suitable distance into one end of the piping and then expanding the mandrel. The expanding or reducing may also be done by a male or female die. It may also be done by spinning the piping with or without application of heat i.e. by spin casting.

A plurality of bell formations may be formed in succession from a length of piping by expansion or reduction of one end of the piping, then cutting the piping a suitable distance from the expanded or reduced portion, and then expanding or reducing the end of the piping upwardly of the cut, and so on.

The narrower portion of the piping may then be provided with a suitable locating formation for receiving the thickened region of the pin of another insulator.

In one embodiment, the locating formation may be in the form of a clip having limbs receivable transversely in suitable apertures provided in the narrower portion of the piping.

The clip may be U-shaped and its limbs may have tapering leading edges to facilitate a resilient interference fit insertion of the limbs around the pin inwardly of the thickened region of the pin.

In another embodiment, an axially extending slot may be provided in the wall of the narrower portion of the piping, the inner end of the slot being wider than its outer end to receive the thickened region of the pin laterally. The narrower portion of the piping would then have a smaller diameter than the thickened region of the pin.

In order to inhibit outward expansion of the narrower portion of the piping under load, a collar or washer may then be fitted around the narrower portion to reinforce it.

In still a further embodiment, the locating formation may include a transverse key element locatable in a transverse aperture in the narrower portion of the bell formation, the key element being locatable in a mating aperture in the pin.

A plug or rib may also be fitted internally of the piping at or near the junction of the narrower and broader portion of the piping to define with the broader portion a hollow recess into which the cap of the capped disc is receiv able. A cement is then usually inserted intermediate the cap and the broader portion of the piping.

Various embodiments of the invention are now described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a schematic side elevation of a number of insulators in accordance with the invention interconnected together; Figure 2 shows a sectional view of an insulator; Figure 3 shows a sectional view of a bell formation in accordance with the invention; Figure 4 shows a section along line IV-IV of Figure 3; Figure 5 shows a perspective view of a clip used with the bell formation; Figure 6 shows a perspective view of a further form of bell formation in accordance with the invention; Figure 7 shows a sectional view of the bell formation of Figure 6; Figure 8 shows a perspective view of still a further form of bell formation in accordance with the invention;; Figure 9 shows a sectional view of the bell formation of Figure 8; Figure 10 shows a sectional view of a further form of bell formation in accordance with the invention; and Figure 11 shows a perspective view of a modified form of pin used with the bell formation of Figure 10.

Referring to Figure 1, reference numeral 10 generally indicates a number of insulators interconnected together and which are suspended in use from a pylon to support high voltage power transmission lines. Each insulator comprises a capped disc 12 of glass or porcelain, a bell formation 14 and a pin 16.

As shown more clearly in Figure 2, the bell formation 14 is fitted above and around the cap 18 of the disc 12, usually with a cementitious mixture intermediate the cap 18 and bell formation 14. One end of the pin 16 is located in the cap 18 also by a cementitious mixture 20. The outwardly extending end 22 of the pin 16 is thickened to permit a further insulator to be suspended therefrom.

As shown more clearly in Figure 3, the bell formation 14 is formed of conventional piping and has an expanded portion 24 which, prior to expansion, was the same size as an unexpanded portion 26. Of course, the reverse can also be done, i.e. piping having a diameter of the portion 24 can have its portion 26 made narrower.

Expansion of the portion 24 can be achieved in a number of ways but preferably using a mandrel which is inserted in one end of the piping and then expanded.

In this embodiment, a Welsh plug 28 is fitted near the junction of the portions 24 and 26 to define with the portion 24 a hollow recess 30 for receiving the cap 18 and cementitious mixture.

The pin 16 of another insulator is located within the portion 26 by a clip 32 as shown in Figure 5. The clip 32 has limbs 34 and a junction 36. The limbs 34 have tapering leading edges 38 to facilitate a resilient interference fit insertion of the clip 32 around the pin 16. The clip 32 is held in suitable apertures 40 provided in the portion 26 of the bell formation 14.

As shown in Figures 6 and 7, in accordance with another embodiment of this invention, location of the pin 16 may be accomplished by providing an axial slot 42 in the portion 26.

The thickened portion 22 of the pin is receivable in a wider zone 44 of the slot 42. In order to inhibit outward expansion of the portion 26 under load, a collar 46 is located around the portion 26.

Again a Welsh plug 28.1 is fitted near the junction of the portions 26 and 24.

In the Figures 8 and 9 embodiment, instead of a collar 46, a washer 48 is located around the portion 26.

In Figures 10 and 11, a deeper plug 28.2 is fitted into the narrower portion 26 of the bell formation and a pin-like key element 32.1 is fitted transversely into an aperture in the narrower portion 26. The key element 32.1 is passed through registering holes in the plug 28.2 and a mating aperture 50 in the pin 16 which is suitably modified as shown in Figure 11. The key element is held in position by a split pin or the like passed through an aperture 52 in the key element 32.1.

The invention illustrated provides an insulator with a bell formation which can be inexpensively manufactured in mass production. A light weight bell formation is provided thereby reducing the overall loading on pylons yet, it is believed, the bell formation is as equally effective as the heavy expensive forged bell formations used previously.

By way of development, the portion 26 may taper inwardly in a direction away from the portion 24.

WHAT I CLAIM IS: 1. An insulator consisting of a capped disc, a pin secured axially to the disc and projecting downwardly from it, and means for connecting the insulator to a second, identical insulator, such means consisting of a bell formation having a body surrounding and secured to the cap of the disc, a shank adapted to receive the projecting pin of the second insulator, and means to anchor the pin in the shank.

2. The insulator of Claim 1 in which the bell formation is made of thin-walled tubing, a portion of which is restricted in diameter to form the shank.

3. The insulator of Claim 1 or Claim 2 in which the anchoring means consists of a device projecting through the wall of the shank to

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. able. A cement is then usually inserted intermediate the cap and the broader portion of the piping. Various embodiments of the invention are now described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a schematic side elevation of a number of insulators in accordance with the invention interconnected together; Figure 2 shows a sectional view of an insulator; Figure 3 shows a sectional view of a bell formation in accordance with the invention; Figure 4 shows a section along line IV-IV of Figure 3; Figure 5 shows a perspective view of a clip used with the bell formation; Figure 6 shows a perspective view of a further form of bell formation in accordance with the invention; Figure 7 shows a sectional view of the bell formation of Figure 6; Figure 8 shows a perspective view of still a further form of bell formation in accordance with the invention;; Figure 9 shows a sectional view of the bell formation of Figure 8; Figure 10 shows a sectional view of a further form of bell formation in accordance with the invention; and Figure 11 shows a perspective view of a modified form of pin used with the bell formation of Figure 10. Referring to Figure 1, reference numeral 10 generally indicates a number of insulators interconnected together and which are suspended in use from a pylon to support high voltage power transmission lines. Each insulator comprises a capped disc 12 of glass or porcelain, a bell formation 14 and a pin 16. As shown more clearly in Figure 2, the bell formation 14 is fitted above and around the cap 18 of the disc 12, usually with a cementitious mixture intermediate the cap 18 and bell formation 14. One end of the pin 16 is located in the cap 18 also by a cementitious mixture 20. The outwardly extending end 22 of the pin 16 is thickened to permit a further insulator to be suspended therefrom. As shown more clearly in Figure 3, the bell formation 14 is formed of conventional piping and has an expanded portion 24 which, prior to expansion, was the same size as an unexpanded portion 26. Of course, the reverse can also be done, i.e. piping having a diameter of the portion 24 can have its portion 26 made narrower. Expansion of the portion 24 can be achieved in a number of ways but preferably using a mandrel which is inserted in one end of the piping and then expanded. In this embodiment, a Welsh plug 28 is fitted near the junction of the portions 24 and 26 to define with the portion 24 a hollow recess 30 for receiving the cap 18 and cementitious mixture. The pin 16 of another insulator is located within the portion 26 by a clip 32 as shown in Figure 5. The clip 32 has limbs 34 and a junction 36. The limbs 34 have tapering leading edges 38 to facilitate a resilient interference fit insertion of the clip 32 around the pin 16. The clip 32 is held in suitable apertures 40 provided in the portion 26 of the bell formation 14. As shown in Figures 6 and 7, in accordance with another embodiment of this invention, location of the pin 16 may be accomplished by providing an axial slot 42 in the portion 26. The thickened portion 22 of the pin is receivable in a wider zone 44 of the slot 42. In order to inhibit outward expansion of the portion 26 under load, a collar 46 is located around the portion 26. Again a Welsh plug 28.1 is fitted near the junction of the portions 26 and 24. In the Figures 8 and 9 embodiment, instead of a collar 46, a washer 48 is located around the portion 26. In Figures 10 and 11, a deeper plug 28.2 is fitted into the narrower portion 26 of the bell formation and a pin-like key element 32.1 is fitted transversely into an aperture in the narrower portion 26. The key element 32.1 is passed through registering holes in the plug 28.2 and a mating aperture 50 in the pin 16 which is suitably modified as shown in Figure 11. The key element is held in position by a split pin or the like passed through an aperture 52 in the key element 32.1. The invention illustrated provides an insulator with a bell formation which can be inexpensively manufactured in mass production. A light weight bell formation is provided thereby reducing the overall loading on pylons yet, it is believed, the bell formation is as equally effective as the heavy expensive forged bell formations used previously. By way of development, the portion 26 may taper inwardly in a direction away from the portion 24. WHAT I CLAIM IS:

1. An insulator consisting of a capped disc, a pin secured axially to the disc and projecting downwardly from it, and means for connecting the insulator to a second, identical insulator, such means consisting of a bell formation having a body surrounding and secured to the cap of the disc, a shank adapted to receive the projecting pin of the second insulator, and means to anchor the pin in the shank.

engage the pin in the shank.

4. The insulator of Claim 3 in which the device is a clip adapted to straddle a headed pin in the shank.

5. The insulator of Claim 3 in which the device is a cross pin extending through the wall of the shank and through a hole in the pin.

6. The insulator of Claim 1 or Claim 2 in which the shank is keyhole slotted for passage into it of a pin having a head larger in diameter than the inner diameter of the shank; and a collar around the shank to occlude at least part of the slot.

7. An insulator as claimed in Claim 1 in which the bell formation is substantially as herein described with reference to Figures 1 to 4 of the accompanying drawings.

8. An insulator as claimed in Claim 1, in which the bell formation is substantially as herein described with reference to Figures 6 to 9 of the accompanying drawings.

9. An insulator as claimed in Claim 1, in which the bell formation is substantially as herein described with reference to Figure 10 of the accompanying drawings.

10. An insulator substantially as herein described with reference to the accompanying drawings.