AU611864B2

AU611864B2 - Insulated mounting assemblies

Info

Publication number: AU611864B2
Application number: AU79817/87A
Authority: AU
Inventors: Felix Haar
Original assignee: PEKO GOLD Ltd
Current assignee: PEKO GOLD Ltd
Priority date: 1986-10-30
Filing date: 1986-10-30
Publication date: 1991-06-27
Anticipated expiration: 2007-10-15
Also published as: AU7981787A

Description

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4m i 111!11 6 COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION (Original) FOR OFFICE USE Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: SPriority: o Related Art: 0.

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f' ~r P-rek-t&~-nana-l-L 4-t-ed- -1,ame of Applicant:

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.00 Address of Applicant: 0 6Actual Inventor 00 Address for Service: o a -Fai-rban-k- Road, e t( t O CC Clayton 3-168, i-n-t-he--St-ate-of- V-ictoria-, C if I Commonwealth- -of-Austra-lia DAVIES COLLISON, Patent Attorneys, 1 Little Collins Street, Melbourne, 3000.

Complete specification for the invention entitled: "INSULATED MOUNTING ASSEMBLIES" The following statement is a full description of this invention, including the best method of performing it known to us 1 (a member of the firm ot UAVJ a& COLLISON for and on behalf of the Applicant).

Davies Collison, Melbourne and Canberra.

r 7 c~i -II- -CI~ Ir- i -r-ll--ni I I 0 1 0 0 o ooo 0 o o 0 00 000 on 0 0 a o Q 0 a 80 e 0 0 00 0 0 0 00 0 0 0 0 0 "INSULATED MOUNTING ASSEMBLIES" The present invention relates to insulated mounting assemblies, and more particularly to aerial platforms incorporating such assemblies.

Transportable aerial platforms for use in servicing power lines usually comprise an articulated hydraulic boom assembly supported at its inner, lower, end from a vehicle, and carrying at its outer, upper, end an insulated open-topped personnel carrier, known as a basket, which is raised and lowered by means of the boom. Typically, the basket is formed of fibre reinforced plastics (FRP). For high voltage work, the outer section of the boom is composed of an insulated material, typically also fibre reinforced plastics, to ensure there is no risk of an electric current leakage path being established from the inside and top surfaces of the basket down to earth. For lower voltage work, the boom is typically of all-steel construction, this being less expensive and requiring less maintainance and inspection than the steel-FRP composite boom used for

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Signature of declarant(s) (no aftcstation required) Note- Initial all alterations.

-AVIS O MELBOURN and CANBERRA DAVH..S ('OLLISON. MELBOURN" and CANBERRA.

Irp -3- 0, 44 0 0 4 040009 0 0 0 0 0 0 0 00 0 0 44 0 00a O QO 0 0 0 o 0 o0 0 0 a ou 4 400 0 4 004004 o 0 4 o o o 0 4 0 04 00 0 4 o o a« o a high voltage work. Insulation is provided just by the insulated basket, and it has been found that on occasions, an electric leakage path may be established to earth.

According to the present invention, there is provided an aerial platform comprising an insulated personnel carrier, a boom, and a plurality of insulated mounting assemblies mounting the carrier from the boom, each said mounting assembly comprising bolt means for securing the carrier to the boom, an electrically insulated casing enclosing in a sealed manner at least that part of the bolt means extending between the carrier and boom, and sealing means operative to prevent access of moisture and dirt to the external surface of at least that portion of the casing extending between the carrier and boom.

An embodiment of the invention will now be described by way of example only, with reference to the accompanying drawing, the sole figure of which is a cross section through a connection between an insulated basket and a mounting plate at the end of a boom of an aerial platform.

With reference to the accompanying drawing, a basket of an aerial platform comprises a metal frame including a mounting plate 2 and tubular frame members of which one is shown at 4 in the drawing. The frame is incorporated within a shell (not shown) of insulated material, for example of molded plastics or fibre-reinforced plastics, which constitutes the main body of the basket. The mounting plate 2 is exposed at the rear of the basket and is adapted for bolted connection to a plate 6 at the end of the outer section of the boom. The plate 6 is pivotally connected to the boom for limited pivotal movement about a horizontal axis and is controlled to remain in a substantially vertical plane at all inclinations of the boom.

910108,RSHDAT.022,79817.res,3 4 In accordance with the invention, the bolted connection between the two plates is formed by insulated mounted assemblies to obviate the risk of tracking between the basket and the boom. Each such mounting assembly comprises a stepped, tubular, insulated casing 8 which substantially encloses the bolt 10. The enlarged inner end portion of the casing 8 shown at 12 is located internally of the plate 2 and opens into the interior of the basket, this end portion being of a size to receive and fully enclose the inner end of the bolt 10, a clamping nut 14, and a clamping washer 16. An external shoulder o 18 at the base of the enlarged end portion 12 engages othe mounting plate 2 whereby the base is clamped between the washer 16 and the mounting plate 2.

An annular spacer 20, also of insulated material, surrounds the main body of the casing 8 between the opposed surfaces of the two mounting plates 2, 6. The outer end of the casing 8 stops a slightly short of the outer surface of the mounting oo plate 6 for reasons which will be discussed shortly.

A clamping washer 22 is interposed between the head 24 of the bolt and the outer surface of the plate 6.

A cap 26 closes the free end of the enlarged inner end portion 12 of the casing 8, an O-ring seal S° 28 being provided between the cap 26 and the casing 8 to prevent ingress of moisture or dirt from that end into the casing. An O-ring seal 30 is interposed between the outer, end of the casing 8 and the washer 22 to prevent ingress of dirt or moisture from that end into the casing. This latter O-ring seal also seals the external surface of the casing against ingress of moisture and dirt between that surface and the mounting plate 6. Further O-ring seals 32 at the 1 I il..l-l. U end faces of the spacer and at the shoulder 18 of the casing 8 also act to prevent penetration of moisture and dirt at the external surface of that portion of the casing extending between the inner surface of the mounting plate 2 and the mounting plate 6.

The insulated connection between the two mounting plates 2,6 is thus sealed both internally and externally against moisture and dirt penetration which diminishes the risk of tracking.

As will be readily apparent, in an alternative arrangement, the bolt head may be housed within the enlarged end portion 12 of the casing, o with the nut being exposed behind the plate 6.

SThe casing 8 and the spacer 20 are o- preferably formed from a strong, insulating, plastics OaeOmaterial such as "ERTALYTE" (Trade Mark) which is an unreinforced partly crystalline thermoplastics '4 polymer based on polyethylene terephtalate.

o The plates 2 and 6 are connected by several ~such mounting assemblies. Existing aerial platforms °comprising plates 2 and 6 bolted directly together 0. may readily be converted to include the insulated 4c4L mounting assemblies The embodiment has been described by way of 0o example only and modifications are possible within the scope of the invention.

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Claims

2. A platform according to claim 1, wherein each c mounting assembly further comprises a tubular spacer between opposed surfaces of the carrier and boom to separate the carrier and boom, the spacer surrounding a portion of the casing which extends between the carrier ,and boom, and said sealing means comprising a seal interposed between each respective end of the spacer and the adjacent surface of the carrier or boom.
3. A platform according to claim 1 or claim 2, wherein 4 the bolt means comprises a nut or bolt head within an .0 oOno~ enlarged end portion of the casing, the nut or bolt head being accessible via a removable sealed cap which closes said end portion. 0 0
4. A platform according to claim 3, wherein the 0o enlarged end portion of the casing is seated and sealed relative to a surface of one of said carrier or boom, said surface facing away from the other of said carrier or boom. A platform according to any one of the claims 1 to 4, wherein the bolt means comprises a bolt having a head C q 910108,RSHDAT.022,79817.res,6 -7- or nut externally of the casing, the casing having an end terminating within one of said carrier or boom short of the head or nut and adjacent to the head or nut, and the sealing means comprises a seal on the shank of the bolt between the head or nut and the adjacent end of the casing, said seal also engaging a surrounding surface of the said one of said carrier or boom component.
6. A platform according to any one of claims 1 to wherein the casing is composed of a partly crystalline thermoplastics polymer.
7. An aerial platform comprising insulated mounting assemblies substantially as hereinbefore described with reference to the accompanying drawings. Dated this 4th day of January, 1991 By their Patent Attorneys DAVIES COLLISON 0 0 .00 0 0 0 0 00 00 0 Od 0 ol o 0 00 000000 o 0 0 0 a C 0 00 910108,RSHDAT.022,79817.res,7 p1