Method for moisture proof covering a connection point between an electrical conductor and a contact element

Abstract

A method is disclosed for moisture tight covering a connection point between an electrical conductor. The method includes exposing the conductor at its end by removing the insulation and subsequently electrically conductively connecting the end of the conductor, from which the insulation has been removed, to the contact element. After the connection point is finished, a foil of insulation material is positioned underneath the connection point, where the foil rests against the insulation of the conductor and at least partially against the contact element. Subsequently, a sealing material capable of hardening is applied from above onto the conductor, wherein the sealing material is flowable during its application and subsequently changes over by hardening into a mechanically stable state which extends beyond the insulation of the conductor and beyond the contact element and is connected tightly to the foil.

Claims

1. Method for moisture proof covering a connection point between an electrical conductor, which comprises individual wires and which is surrounded by an insulation, and a contact element of metal in a form of a flat strip with a rectangular cross section, said method comprising the step of: the wires of the conductor are initially exposed at an end of said conductor by removing the insulation, the wires then being compacted together at a distal end of the conductor; subsequently the wires from which the insulation has been removed is electrically conductively connected to the contact element in the form of the flat strip with the rectangular cross section in the connection point by soldering or welding, the contact element remaining in said form of the flat strip with the rectangular cross section; finally the connection point between the wires and the contact element is covered by following steps including, wherein after finishing the connection point, a foil of insulation material is positioned underneath the contact element which rests against the insulation of the conductor and at least partially against the contact element, a spacer member is placed between the foil and the contact element, where the spacer member constructed as at least one of a disk and ribs with a surface area which is smaller than the surface area of the contact element in the form of the flat strip, and wherein subsequently, sealing material which is capable of hardening is applied from above onto the connection point between the conductor and the contact element, where the sealing material is flowable when applied and then changes over into a mechanically stable state as a result of hardening, and where the sealing material spreads between the contact element and the foil, and extends beyond the insulation of the conductor and beyond the contact element in the form of the flat strip and is fixedly connected to the foil so that a gap between the conductor and its insulation is closed by the sealing material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The method according to the invention will be explained with the aid of an embodiment illustrated in the drawings.

(2) In the drawing:

(3) FIG. 1 is an elevation view of an electrical line with a conductor constructed as a strand and a contact element, shown separated from each other.

(4) FIG. 2 is a sectional view taken along sectional line II-II of FIG. 1, on a larger scale.

(5) FIG. 3 shows a sectional view taken through a connection point between the strand and the contact element according to FIG. 1, in a schematic illustration.

(6) FIG. 4 shows a detail of FIG. 3 on a larger scale.

DETAILED DESCRIPTION

(7) FIG. 1 shows an electrical line L which is composed of a strand 1 and an insulation 2 surrounding the strand. In accordance with FIG. 2, the strand 1 is constructed with a plurality of individual wires 3 which are preferably stranded or twisted together. The individual wires 3 may be, for example of copper or of aluminum or of a copper alloy or an aluminum alloy. The insulation 2 may be composed for example of polyethylene or polyurethane. In accordance with FIG. 1, the insulation is removed at the end of the line L, so that the strand 1 is exposed at this location and can be used for directly connecting to electrical contacts or from electrical contacts.

(8) In the present case, the strand 1 is electrically conductively connected to a contact element 4 of metal which is part of an electrical device 5 which is only shown schematically. The contact element 4 may be for example, a flat strip with a rectangular cross section. However, it may also have a different geometric shape. The strand 5 is advantageously combined and advantageously compacted at its free end in such a way that no individual wires 3 project laterally therefrom. Subsequently, the strand 1 is electrically conductively connected to the contact element 4, for example, by soldering, or advantageously by welding. Compacting and soldering or welding of the strand 1 to the contact element 4 can also be carried out in only one work step. A connection point V resulting from this treatment is shown schematically in FIG. 3 surrounded by a broken line. For example, such a connection point V is covered in a moisture proof manner by means of the method according to the invention as follows:

(9) Initially, a foil 6 of insulation material is placed from below against the connection point V or the connection point V is placed on the foil 6. In both cases, the foil 6 rests against the insulation 2 of the line L as well as to the contact element 4. Advantageously, it projects on all sides beyond the actual connection point V between strand 1 and contact element 4. Suitable materials for the foil 6 are, for example, polyethylene terephthalate, polyurethane, polyvinylchloride, polyamide and polyethylene.

(10) Subsequently, an initially flowable sealing material is placed from above onto the connection point V, preferably directly onto the strand 1. This can be carried out by casting or by drops or also by using a type of syringe. Suitable sealing materials are polyvinylchloride, polyurethane, polyamide, silicon rubber as well as fluoroethylenepropylene and perfluoroalkoxy polymer. It may consist of only one material, or it may be a material composed of two different components. The flowable sealing material penetrates between the individual wires 3 of the strand 1. The foil 6 catches the sealing material as the material moves downwardly, so that the material can only spread out in the connection point V itself and around the connection point V. The sealing material also penetrates over a short distance into the circumferential gap existing between strand 1 and insulation 2 of the line L, which closes the gap. The sealing material finally extends on one side beyond the insulation 2 of the line L, and on the other side beyond the contact element 4. After being applied, the sealing material hardens relatively quickly, so that a mechanically stable sealing member 7 is obtained which seals the connection point V effectively against moisture.

(11) In accordance with FIG. 4, a spacer member 8 may be arranged between the foil 6 and the contact element 4 before the sealing material is applied. The spacer member 8 has a smaller surface as compared to the surface of the contact element 4. If the spacer member 8 is used, the sealing material can also spread out between the contact element 4 and the foil 6, so that the contact element 4 is almost completely surrounded by sealing material in the area of the connection point 4. For example, the spacer member 8 which consists of any chosen material may be constructed as a disk, or may consist of ribs which, prior to mounting the foil 6, are arranged or fastened to the insulation 2 of the conductor 1 and to the contact element 4.

(12) No expensive tools or molding equipment are required for carrying out the method because the sealing material can be applied onto the connection point V without limiting structural componentswith the exception of the foil 6onto the connection point V.