Method for attaching a contact element to the end of an electrical conductor

Abstract

A method for attaching a contact element to the end of an electrical conductor is provided. In the method electrically conductive material is shaped to form a contact element with a variable shape. The end of the bare conductor is firstly moved into an at least approximately vertical position. Particles of an electrically conductive material are then applied at a high speed to the upwardly projecting front-side end of the conductor in the axial direction thereof that the material of the conductor connects to the electrically conductive material to form a compact structure which is connected to the material of the conductor in a mechanically fixed and electrically conductive fashion. Additional particles of the electrically conductive material are applied to the compact structure, and the metal body is shaped mechanically to form the contact element.

Claims

1. Method for making a contact element at the end of an electrical conductor, where electrically conductive material which is present at the end of the conductor and which is fixedly connected to the conductor is shaped to form the contact element, the contact element having a variable shape, said method comprising the steps of: moving a bare front-side of the conductor into a vertical position relative to a ground surface, such that said bare-front side is accessible from above; applying particles of the electrically conductive material downwardly, at a supersonic speed, to the upwardly projecting bare front-side end of the conductor in an axial direction thereof from a likewise vertically arranged pipe which acts as a nozzle, sufficient that a material of the conductor connects with the electrically conductive material from said pipe forming a compact surface-normal structure which is connected to the material of the conductor in a mechanically fixed and electrically conductive fashion, wherein said pipe includes a constriction for obtaining said supersonic speed of said electrically conductive particles; without interruption, continuing to apply additional particles of electrically conductive material to the compact structure forming a metal body; and mechanically shaping the metal body to form the contact element.

2. The method according to claim 1, wherein the conductor is used which is constructed from a plurality of wires which are combined to form one unit and which consist of aluminium or of an aluminium alloy.

3. The method according to claim 1, wherein a copper or a copper alloy is used as a material for the particles.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The method according to the invention will be explained as an exemplary embodiment with reference to the drawings, in which:

(2) FIG. 1 shows the end of an electrical conductor with the insulation removed.

(3) FIG. 2 shows the end of the conductor according to FIG. 1 after processing with the method according to the invention.

(4) FIG. 3 shows a schematic illustration of an arrangement for carrying out the method according to the invention.

(5) FIG. 4 shows a pipe which can be used in the method according to the invention.

(6) FIG. 5 shows different contact elements which can be produced with the method according to the invention.

DETAILED DESCRIPTION

(7) In FIG. 1, the end of an insulated electrical conductor L is shown which is embodied in the illustrated exemplary embodiment as a stranded conductor which comprises a plurality of individual wires 1. The conductor can, however, also be a solid conductor. Insulation 2 which surrounds the conductor L is removed therefrom at its end. Particles of electrically conductive material are applied to the front side of the conductor L, in its axial direction corresponding to the arrow 3, at a high speed which is advantageously higher than the speed of sound. The corresponding method will be further explained below in more detail with reference to FIG. 3.

(8) The method according to the invention at first is used to generate, at the end of the conductor L, a compact structure which is indicated in FIG. 2 and illustrated as a composite body 4 which is shown in hatched form and is composed of the material of the conductor L, on the one hand, and, on the other hand, of the metal which is applied by the particles and is connected in a metallurgically fixed fashion to the material of the conductor L in the composite body 4.

(9) In addition, a metal body 5 which consists only of the material of the particles is generated on the composite body 4 by the particles of the electrically conductive material which further impinge on said composite body 4. Said metal body 5 is connected in a metallurgically fixed fashion to the composite body 4. The metal body 5 is shown in FIG. 2 with a different hatching from that of the composite body 4.

(10) The method according to the invention is carried out, for example, as follows:

(11) In order to feed, for example, particles which consist advantageously of copperreferred to below for short as particles- to a conductor L which consists, for example, of aluminium, a pipe 6 which acts as a nozzle is used which is arranged in the axial direction of the conductor L which is arranged with a vertical profile, above said conductor L. Gas coming from a gas source 7, advantageously an inert gas, is blown as a gas stream into the pipe 6, at its one end, from a gas source 7. Particles, which are contained in a reservoir 8 of particles, are fed into the gas stream before it enters into the pipe 6. The gas stream can be passed through the particles. However, in any case, the particles are arranged in such a way that they are picked up and transported by the gas stream.

(12) The conductor L is advantageously arranged in a tool 9 in such a way that only its tip projects out of the latter. The tool 9 holds together the wires 1 of the conductor L, if the latter is a stranded conductor, and protects the insulation 2 of the conductor L with respect to the particles. The tool 9 can advantageously consist of multiple parts. The gas stream 10 which is loaded with the particles exits the pipe 6 at the free end thereof at a high speed which is advantageously higher than the speed of sound. Said gas stream impinges on the front side of the conductor L. The gas stream 10 therefore has the function of a carrier for the particles which as a result impinge on the front side of the conductor L at the same speed as the gas. The metal body 5 which has already been described and which also encompasses the composite body 4 is generated by the particles.

(13) The pipe 6 is positioned at a distance from the front side of the conductor L in accordance with FIG. 3. The distance is variable. It depends on the material of the particles and is preferably between 20 mm and 105 mm.

(14) The pipe 6 which has an overall circular cross section can have, in its length corresponding to the purely schematic illustration in FIG. 4, a constriction 11 of its clear cross section, as a result of which the required speed of the gas stream and therefore the required speed of the particles can be achieved in accordance with the function of the above mentioned Laval nozzle.

(15) After the method ends, the conductor L is connected at its end in a metallurgically fixed fashion to the metal body 5, and specifically in the junction region with the compact structure which is referred to above as composite body 4. The metal body 5 which also contains the composite body 4 can then be shaped mechanically to form a contact element K with any desired shape for different applications. Six examples of possible contact elements K are shown schematically in FIGS. 5a to 5d. The contact element K according to FIG. 5a can be used, for example, as a connection to the pole of a battery as what is referred to as a battery terminal. For example, a contact element K which is embodied as a plug pin is represented in FIG. 5d.