Abstract

The present invention relates to grading devices (1) for reducing electrical stress in two or more electrically insulating members (29) of an electricity network tower. Preferably, a grading device (1) for reducing electrical stress in two or more electrically insulating members (29) of an electricity network tower, each electrically insulating member (29) having means for connecting the electrically insulating member (29) to an electrical power line supported by the electricity network tower, is provided, wherein: the grading device (1) includes two or more grading rings (3, 5, 7, 9), each of which is shaped so that in use it completely or substantially surrounds a respective one of the electrically insulating members (29); and the two or more grading rings (3, 5, 7, 9) are connected together.

IPC Classes  ?

• H01B 17/44 - Structural association of insulators with corona rings
• H01T 19/02 - Corona rings

Abstract

A pipe joining device (1) for forming a junction in pressurised and rehabilitated pipes between a first pipe (2) and a branch pipe (3), the pipe joining device (1) comprising a substantially rigid body (10) at least in part of thermoplastic, the body (10) including a first pipe sealing portion (14) adapted to form a seal with the first pipe (2) and a branch pipe sealing portion (15) adapted to form a seal with the branch pipe (3).

IPC Classes  ?

• F16L 41/08 - Joining pipes to walls or pipes, the joined pipe axis being perpendicular to the plane of a wall or to the axis of another pipe
• F16L 47/28 - Joining pipes to walls or to other pipes, the axis of the joined pipe being perpendicular to the wall or to the axis of the other pipe

Abstract

An electrically insulating cross-arm is disclosed for a tower for high-voltage power networks. The cross-arm includes an insulating structural member for attachment to the tower body and to support a conductor cable. The insulating structural member comprises a solid rigid spine extending along a long axis having cross sectional profile, normal to the long axis, having a second moment of area of its cross sectional profile about every axis normal to the long axis and dissecting its centroid has a value of A2/2π or more, where A is the area of the cross sectional profile. The structural member provides resistance to bending and to compressive buckling and allows conductors to be safely supported at reduced tower height. T and Y shaped cross sections provide particularly good water run-off and inhibition of organic growth on the structural member. In addition to use in tower cross arms, the structural members are generally useful as insulator members in high voltage power networks.

IPC Classes  ?

• H02G 7/05 - Suspension arrangements or devices for electric cables or lines
• H01B 17/00 - Insulators or insulating bodies characterised by their form

Abstract

A polymer composite material (10, 110, 210, 310) is described. The material includes a settable matrix material (12), a plurality of reinforcement members (14) and a plurality of capsule members (16). Each capsule member (16) includes a shell layer (22) encapsulating an indicator material (24). The polymer composite material comprises an initial condition in which each shell layer contains the indicator material, and a damaged condition in which at least one shell layer is ruptured, releasing indicator material. The polymer composite material is changed from the initial condition to the damaged condition by the application of a predetermined force to the polymer composite material.

IPC Classes  ?

• G01L 1/24 - Measuring force or stress, in general by measuring variations of optical properties of material when it is stressed, e.g. by photoelastic stress analysis
• G01M 11/08 - Testing mechanical properties
• G01M 5/00 - Investigating the elasticity of structures, e.g. deflection of bridges or aircraft wings
• G01D 7/00 - Indicating measured values
• G01N 21/91 - Investigating the presence of flaws, defects or contamination using penetration of dyes, e.g. fluorescent ink

Abstract

Bonding apparatus (10) for bonding a thermoplastic first material (12) to a second material (14) includes a heater arrangement (22) for heating a bonding surface (16) of the first material (12) to melt the bonding surface (16) and moving means (30) for moving the first and second materials (12, 14) together to a bonded condition.

IPC Classes  ?

• B29C 65/14 - Joining of preformed partsApparatus therefor by heating, with or without pressure using wave energy or particle radiation
• B29D 24/00 - Producing articles with hollow walls
• B29C 63/00 - Lining or sheathing, i.e. applying preformed layers or sheathings of plasticsApparatus therefor
• B29K 23/00 - Use of polyalkenes as moulding material