GB2306364A

GB2306364A - Metal_arc welding contact tip

Info

Publication number: GB2306364A
Application number: GB9522430A
Authority: GB
Inventors: Christopher Selby Kirk; Antony Roy Mileham
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-11-02
Filing date: 1995-11-02
Publication date: 1997-05-07
Also published as: GB9522430D0

Abstract

A contact tip as illustrated in Figure 1, with a central body 10 made of electrically conducting material and centrally bored to permit the passage of a consumable electrode, with an electrically non-conducting extension 12 of tubular construction or an electrically conducting extension 12, the central core of which encases an electrically non-conducting material 14, centrally bored to permit the passage of a consumable electrode, whereby the extension segment of the device may be made to varying lengths to permit maintenance of a predetermined electrode extension with or without a gas shield.

Description

METAL=ARC WELDING CONTACT TIP This invention relates to a contact tip for use in metal-arc welding Many semi-automatic and automatic welding processes utilise a contact tip to transfer electricity from the power source to a consumable electrode. This consumable electrode is normally in the form of a solid or tubular wire. Research into semiautomatic welding processes proves that electrode extension (the distance between the electrical contact tip and the workpiece), must be carefully controlled if welding quality is to be maintained. With the use of consumable electrode wires which require long electrode extensions in order to function correctly, it is important to assist welders or welding operatives maintain the correct electrode extension consistently.

The Lincoln Electric Company of the United States of America produce a support shroud for their welding machines, but this can only be used for cored wires which do not need a gas shield. Many wire electrodes require a gas shield together with a long electrode extension. This device assists maintenance of the correct electrode extension, permits the use of a gas shield, and is furnished with a screw thread or other connection, which allows it to be connected to any welding gun.

According to the present invention there is provided a contact tip for consumable electrodes for use in welding, joining, cutting or allied processes, which essentially includes an electrical contact section, through the medium of an electrically conducting material, together with an extension tube, orifice, or axial support arrangement, consisting of, in whole or in part, a non-conducting material, inserted into, or otherwise attached to the electrical contact, which provides guidance to the aforementioned consumable electrode, and which enables, by varying the length of the non-conducting extension, a number of electrical or physical distances between the said electrical contact on the one part, and the welding or joining electrical arc or plasma emission on the other, the whole, being finished with a connecting device in the general form of an internal or external screw thread or socket, enabling connection to all types of welding and joining equipment or apparatus howsoever called, named or described. In particular, the device, being of slim construction, enables the passage of shielding gas around both the consumable electrode and the aforementioned contact tip device, through, or by the use of, gas nozzles or shrouds howsoever called, surrounding in part or in whole, which therefore, and as a result of, permits the use and application of, any number and extent of electrical or physical extensions or distances between the electrical contact and the arc or plasma, with or without an active or inert gas shield.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing detailed in Figure 1.

Referring to the drawing expressed in Figure 1, the main body of the contact tip 10 is made of an electrically conducting material which has been centrally bored from point 18 to point 20, to a diameter suitable for the passage ofthe consumable electrode wire.

This diameter will vary, depending on which diameter wire the contact tip is manufactured for. In this example the contact tip is made with a screw thread 16 but it may be made with any one of a number of different connection types.

The contact tip body 10 is fitted with an extension tube 12, made either of nonconducting material or from the same or similar material as the contact tip body 10, but fitted with a non-conducting insert 14, which must be capable of withstanding the heat transferred from the arc which may occur by radiation, convection or conduction.

This non-conducting extension is bored from point 20 to point 22 to a diameter which permits the passage of the consumable electrode wire and will be manufactured in varying lengths to permit a change of electrode extension by changing the contact tip.

The whole device is of slim construction to enable it to fit inside a shroud or gas nozzle through which shielding gas flows. The whole device is therefore able to be used with or without shielding gas.

Claims

1 A contact tip for consumable electrodes for use in welding, joining, cutting or allied processes, which essentially includes an electrical contact section, through the medium of an electrically conducting material, together with an extension tube, orifice, or axial support arrangement, consisting of, in whole or in part, a non-conducting material, inserted into, or otherwise attached to the electrical contact. The whole being finished with a connection in the form of an internal or external screw thread or socket.

2 A contact tip as claimed in Claim 1, being of slim construction.

3 A contact tip substantially as described herein with reference to Figure 1 ofthe accompanying drawing.