AU597234B2 - Cross-arms for utility poles - Google Patents

Description

&U-LI 4 7 8 8/85 PF WORLD INTELLECTUAL P ER ORG ATI PCT Internati ur& INTERNATIONAL APPLICATION PUBLISHED UNI R E P ERATI N TREATY (PCT) (51) International Patent Classification 4 (11) International Publication Number: WO 86/ 01635 H01B 17/16, 17/24, E04H 12/24 Al (43) International Publication Date: 13 March 1986 (13.03.86) (21) International Application Number: PCT/AU85/00203 (81) Designated States: AT (European patent), AU, BE (European patent), CH (European patent), DE, DE (Eu- (22) International Filing Date: 27 August 1985 (27.08.85) ropean patent), FR (European patent), GB, GB (European patent), IT (European patent), JP, LU (European patent), NL (European patent), SE, SE (Euro- (31) Priority Application Number: PG 6896/84 pean patent), US.

(32) Priority Date: 3 September 1984 (03.09.84) Published (33) Priority Country: AU With international search report.

(71) Applicant (for all designated States except US): R.F.D.

S CONSULTANTS PTY. LTD. [AU/AU]; 14 Collins Street, Melbourne, VIC 3000 (AU).

Inventor; and Inventor/Applicant (for US only) KNIGHT, John, S Keith [NZ/AU]; 15 Frederick Street, Doncaster, VIC 3108 (AU).

Agents: McCORMACK, John, David et al.; Davies Collison, 1 Little Collins Street, Melbourne, VIC 3000

AUSTRALIAN

2 4 MAlR 1986 PATENT

OFFICE

(54) Title: CROSS-ARMS FOR UTILITY POLES t a This d tu-nwi t -contaw t "I amendment made unde Sectic 419.

nd Is corroct tar printing.

(57) Abstract Ceramic elements which can be clamped together by means of a tension rod (22) so as to form a cross-arms assembly (23) for a utility for pole The elements are provided with recesses (12) which receive electrical conductors clips (16) being provided so as to retain the conductors within the recesses. The elements thus provide physical support for the conductors and also form the insulating medium for the conductors.

S WO 86/01635 PCT/AU85/00203 1 "CROSS-ARMS FOR UTILITY POLES" The present invention relates to cross-arms for utility poles, particularly cross-arms which provide support for electrical conductors. In particular, the present invention relates to a cross-arm assembly that 5 is both insulating and supportive.

Although the present invention will be described with particular reference to a cross-arm assembly of ceramic bricks or blocks which are manufactured from essentially non-conducting material, the scope of the present invention is not so limited and may extend to other applications of the bricks or blocks and support arm assembly and to other forms of the support assembly.

Cross-arms for utility poles, such as those carrying electrical conductors and insulators, are most usually made of wood and are provided with metal fittings. The wood deteriorates in time, caused by water impregnating the matrix of the wood thus destroying its structure. In addition, the wooden poles when wet or impregnated with moisture can be electrically conductive, particularly so when metal fittings are used to secure the cross-arms. Thus, existing cross-arms of power poles have at least two deficiencies, that of premature ageing and deterioration 2 1 necessitating replacement at a high cost of both labour and 2 replacement materials, and that of the unwarranted 3 conduction of stray currents to undesirable parts of the 4 pole assembly which presents a safety problem since it may cause shock or other injuries to operators or people in the 6 vicinity of the poles.

7 8 Therefore, it is an aim of the present invention to at 9 least provide a cross-arm assembly or cross-arm element which at least alleviates one of the problems of prior art 11 cross arms or cross arm elements.

12 i 13 According to the present invention there is provided a ii 14 utility pole assembly, said assembly comprising: a utility pole, a cross-arm, a bracket connecting the 16 cross-arm to the pole and a pair of stays which extend from 0 17 the pole to spaced locations on the cross-arm, said cross- 18 arm comprising a plurality of ceramic elements each i 19 including a bore therethrough, said elements being arranged so that their bores are aligned, said cross-arm including 21 spacing means located between adjacent elements, each 22 spacing means having openings therethrough, said cross-arm 23 further including a tension member which passes through said 24 bores and said openings and clamps said elements together, and wherein each element comprises a body having a top 26 portion with conductor support means for supporting an 27 electrical conductor which in use extends transversely 28 relative to the cross-arm, said bracket having an opening r 29 therein which is generally complementary in shape to the body so that the cross-arm can extend therethrough and be 31 firmly clamped by the bracket to the pole.

32 33 34 36 37 38 900216.gcpdat.014.47788.c2.2 WO 86/01635 PCT/AU85/00203 3 conductor, and wherein at leact one of th c connected to the pole in use.

According to another asp of the present invention there is pr vied a utility pole having at least one cro s-rm assembly wherein the cross-arm assem comprises a plurality of similar insulating The present invention will now be described by way of example with particular reference to the accompanying 10 drawings in which:- S e Figure 1 is a perspective view of one form of the ceramic block of the present invention; Figure 2 is a cross section view of the block of Figure 1 taken along the line 2-2 of Figure 3; 15 Figure 3 is a view of a utility pole having a cross-arm assembly in accordance with the present invention; Figure 4 is a cross-section view along 4-4 of Figure 3; and Figure 5 is a more detailed front view of the block in the cross arm assembly.

In Figure 1 there is shown a block 2 made of a ceramic material which is non-conductive and may be glazed or impregnated with polymer so as to be moistureor water-proof. The composition of the ceramic block is such that even if the glaze is damaged or deteriorates, water may not WO 86/01635 PCT/AU85/00203" 4 ingress into the matrix of the material to any significant extent and certainly not to such an extent that substantial leakage currents may be conducted through the body of the block.

The block 2 has a base 4 being generally cuboid in shape but having curved longitudinal edges 6. The block 2 has a curved top portion 5 having a relatively thin neck portion 8 and a relatively thicker.head portion The top portion 5 of the block 2 has a transversely extending straight groove 12 which extends through both the neck an- head portions. In use, an electrical conductor 14, such as one of the wires of the electrical supply network, is received in the transverse groove. A slidable locking clip 16 of generally C-shaped cross-section and of complementary contour to the upper contour of the head portion 10, is located on the head portion above the groove 12. The clip 16 can be slid along the head portion so that the conductor 14 may be placed in groove 12. However, once the conductor 14 is located in the groove 12 the locking clip is slidably moved to span the groove 12 and thereby retain the electrical conductor'in the groove, as shown in Figures 2 and 5. *i 99 The base 4 of the block has a longitudinally extending bore 20 located at or near its centre for receiving a tensioning rod 22 or similar tensile member therethrough so as to secure adjacent blocks together (as will be described in more detail later). The reinforcing rod or tensile member is preferably coated or provided with a suitable surface coating or plastic insulating sleeve so that in the event that water enters the central bore 20, the rod 22 will not conduct WO 86/01635 PCT/AU85/00203 electricity. Further the coated rod will not undergo electrolysis reactions, such as rust or other corrosive mechanisms, which would tend to cause deterioration thereof and thus loosen the cross-arm assembly.

Figures 3 to 5 show a cross-arm assembly 23 mounted on a utility pole 24, typically a timber pole, of conventional form by a bracket 26. In assembly the cross-arm assembly 23, the rod 22 is passed through the aligned bores 20 of the blocks and tensioned by means of 0 10 tightening nuts 25 so as to apply compressive forces to 0 the blocks to retain them in a rigid structure. Metal plates 52 are located at the free ends of the blocks in the assembly 23 to evenly distribute the load applied by the tensioning rod 22.

The cross-arm assembly 23 includes a pair of resilient washers 44 and spacer 46 sandwiched *therebetween located between adjacent blocks. The washers and spacers may be formed from rubber or plastics material or material having a surface coating of silicon rubber or sealer. The spacer 44 preferably extend vertically above the plane of the upper surfaces 0 of the heads of the blocks so that birds or workman are unlikely to inadvertently contact two adjacent S. conductors so as to create a short circuit and thereby damage or otherwise disrupt the power supply or conductors or pole assembly.

One form of the bracket 26 is shown in Figure 4 and comprises a first portion 29 which is generally U-shaped in cross section and having one arm 30 substantially longer than and interconnected to the other arm 32 by a web portion 34 extending substantially at right angles WO08601I635 from the pole. In located in the firs central block snug] web portion 34. A a first flange port the upper end of ax 4 second portion 36 i arranged at right a contacting the uppe the block 2 and an engages the upper e portion 29 of the I substantially enclc Thus, the cross-anc present invention i the bracket is sect bolt and nut asseil A pair of forE further secure the movement relativeI the stays are secu PCT/AU85/O20i use the cross-arm assembly 23 is ;t portion of the bracket with the engaged by the arms 30 and 32 and second portion 36 of the bracket has :ion 38 which abuts, in use, against .m 30 of the bracket portion 29. The .ncludes a top flange portion ngles to first portion 38 for ~r surface of the head portion 5 of inclined side portion 42 which ~nd of the shorter arm 32 of the first ~racket to thereby define a sed loop surrounding the block 2.

tassembly 23, in accordance with the Ls clamped within the bracket 26 and ired to the top of the pole by the 1y as shown in Figure 4.

Sstays 48 are optionally provided to cross-arm assembly 23 against pivotal to the pole 24. The lower ends 49 of red to the pole 24 and extend from the irm. The cross arm is provid~ed with which depend downwardly therefrom and Detween adjacent blocks 2. The aferably replace the spacers 46 at the for connection to the stays 48.

p p p p p p p p. .p.

pp p p p p p p p. p YO L.J C41 XO mounting plates 50 which are clamped mounting plates pr selected locations t 4

".M'J

In another embodiment, rear stays (not shown) are located on the opposite side of pole 24 to fore stays 48 and extend from the pole 24 to the cross arm 23 in a manner similar to fore stays 48 and plates 50. The rear stays are substantially in the common plane of blocks 2 forming the cross-arm assembly 23 to prevent twisting or I 7 WO 86/01635 PCT/AU85/00203 rotation of the cross-arm about central longitudinal extending axis of the pole.

In one embodiment the block is 300 mm long, 100 mm in height and 90 mm wide.

Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the invention includes all such variations and modifications which 10 fall within its spirit and scope. For instance, cash block may include two or more grooves 12 for receiving conductors.

0

Claims (3)

1. 4. A utility pole assembly as claimed in claim 3 wherein 31 each conductor support means includes a recess which extends 32 transversely relative to the longest dimension of the body 33 and wherein, in use, a conductor is located in the recess. 34
2. 5. A utility pole assembly as claimed in claim 4 wherein 36 each recess is open to the upper surface of the top portion 37 and the conductor support means includes a clip which is 38 D 900216.gcpdat.014.47788.c2.8 f& A rii r 9 1 resiliently engageable with the top portion and operates in 2 use to hold a conductor captive in the recess. 3 4 6. A utility pole assembly as claimed in claim 5 wherein the top portion includes a rounded head and the clip is 6 slidable along the head. 7 8 7. A utility pole assembly as claimed in claim 1 wherein 9 each spacing means comprises a pair of resilient washers and a spacing element sandwiched therebetween, the tension 11 member passing through the washers and spacing element. 12 13 8. A utility pole assembly as claimed in claim 7 wherein 14 said washers project above and below the top and bottom surfaces of the elements of the cross-arm. 16 17 9. A utility pole assembly as claimed in claim 1 wherein 18 each stay is connected to the cross-arm by means of a stay 19 mounting bracket which is clamped between adjacent elements of the cross-arm. 21 22 10. A utility pole assembly substantially as hereinbefore 23 described with reference to the accompanying drawings. 24 26 27 28 29 DATED this 16th day of February, 1990 R.F.D. CONSULTANTS PTY. LTD. 31 By its Patent Attorneys 32 DAVIES COLLISON 33 34 36 37 SL 38
3. 900216.gcpda.014 .47788.c2.9