CONNECTOR

Abstract: An in-line electrical wire connector comprises a metal insert located within a heat shrinkable sleeve. The insert comprises two overlapping portions (2, 3) for receiving wires from opposite directions. A strip of solder is disposed at the overlap and can flow through apertures in the inserts so as to effect overlapping electrical connection with the wires and the insert (2, 3). Projections (16) extend inwardly into the wire-receiving portions (2, 3) of the insert, to grip the wires and to provide a temporary electrical connection therebetween. Sealing rings (8) are provided within the heat shrinkable sleeve beyond the end of the insert (2, 3).

Description: CONNECTOR The present invention relates to a wire connector in the form of a heat shrinkable sleeve containing a solder insert. It is known to join wires end to end by inserting them into opposed ends of a sleeve of heat shrinkable material containing a solder insert. The insulation is stripped from the ends of the wires so that the conductors can make contact. The heat shrinkable sleeve is heated to cause the sleeve to shrink and grip the wires and to melt the solder insert so that the solder establishes electrical contact with the exposed conductors. Connectors for this purpose are available from Rayche under its trademark SOLDERSLEEVE. Connectors in which the wires enter from opposed ends are sometimes known as in-line connectors. WO93/ 16505 discloses such a connector comprising a heat shrinkable sleeve and a solder insert for joining wires end to end. The heat shrinkable sleeve also contains a metal insert in the form of a tube, which in turn contains the solder insert. The tube has two openings formed by depressing portions of the tube wall on the same side of the wall to form tabs which project into the tube. These tabs grip the exposed conductors of wires inserted into the sleeve but because they are formed on the same side of the tube the conductors are constrained to meet end to end. GB 1572038 discloses a crimp connector, not a solder connector. There is a central stop which prevents overlap between wires inserted from opposite ends. WO 93/17467 discloses a connector in which there is a heat shrinkable sleeve, and solder to give a permanent connection. An insert in the form of a double cone of coiled copper wire is provided. If wires with a diameter sufficiently great to be gripped by the narrowest part of each core are used then the wires will meet end to end. WO 93/11584 discloses another connector with an insert in the form of a wire coil decreasing in diameter towards the centre. There is, however, still a need for improved in-line connectors, particularly for connecting bundles of cables as is sometimes necessary in connecting wiring harnessing in the production of automobiles. It is also sometimes necessary, or at least desirable, to test the electrical continuity of wires to be connected before they are finally soldered into place. A connector which will provide sufficient electrical contact for testing before soldering is thus desirable. It is also be desirable to provide better and more reliable electrical contact than is obtained by simply aligning individual conductor ends. According to one aspect of the present invention there is provided a connector for making in-line connections between wires, said wire connector comprising : a heat shrinkable sleeve, a metal insert within said sleeve for receiving the conductors of wires to be connected, a solder blank within said sleeve disposed so as to flow, when melted, into contact with the metal insert and with the conductors when said conductors are received within the metal insert, wherein the metal insert comprises first and second conductor receiving means for receiving at least one first and at least one second conductor of at least one first and at least one second wire inserted from first and second ends of the sleeve respectively, said first and second receiving means defining openings decreasing in the direction of insertion of the first and second conductors respectively, said first and second receiving means being so disposed that parts of the first and second conductors overlap within the sleeve. References to first conductor receiving means are to be understood as referring to means which receive only the conductors from a first wire, and references to second conductor receiving means are to be understood as referring to means which receive only the conductors of the second wire. Arranging for a wire to be received by only one receiving means has the effect that the receiving means can be sized to the core and retain a given size of wire. A receiving means into which wires could be inserted from either end of the sleeve would be either too large at its narrowest part to grip each wire satisfactorily or alternatively could not allow the wires to overlap. Preferably the first and second conductor receiving means are so shaped that when the solder is melted a direct conductor-to-conductor contact is obtained by means of the solder. In a preferred embodiment of the invention the first and second receiving means are of substantially the same shape and are aligned one above the other so as to present cable receiving openings facing in opposed directions. The metal insert may comprise two hollow half cones with their bases facing in opposite directions and their flat faces in contact. The metal insert may comprise two half quasi-cones. By "quasi-cones" we mean in this specification a shape with a base which is non-circular but which is symmetric about a centre and whose outer walls converge to an apex on an axis perpendicular to the centre of symmetry of the base. Thus for the purpose of this specification a pyramid, which may have 3 or 4 sides, is an example of a quasi-cone. Although reference has been made to cones and quasi-cones it should be understood that frusto-conical elements are also included when reference is made to cones or quasi-cones. While geometrically the cone or quasi-cone has a base, the geometric base in conical elements used in the metal insert in is fact open to allow insertion of conductors. The physical base of the half-cone in the sense of the side on which it will be most stable is the flat surface obtained by bisecting the cone. It may be convenient to refer to this as the half-side rather than the physical base. As indicated above a half quasi-cone will have a flat surface corresponding to a cut through the apex to the base of the quasi-cone. In the metal insert the two receiving means will be in contact along this flat surface which is preferably provided with at least one communicating aperture. At least one solder blank is preferably provided in contact with the aperture linking the two receiving means. Separate solder blanks however may be provided for each receiving means, and may be shaped so as to fit within the receiving means. It is particularly preferred to form the metal insert from two separate identical components having means for holding each other in head-to-tail relationship. With such components a single solder blank may be provided held between the two metal components constituting the first and second wire receiving means. The solder blank may be shaped so as to extend outwardly from a waisted portion of the metal insert resulting from the head-to-tail superposition of the first and second receiving means. The receiving means may be provided with projections extending into the space provided for receiving conductors. These projections help to retain the conductors in the sleeve before and while the sleeve is being shrunk to grip the wire inserted into it. The projections may be tongues of metal obtained by cutting part of the wall defining the receiving means and pressing the cut out portion inwards. Alternatively the projections, which act in a manner corresponding to the barbs of an arrow, may be provided in a separate insert which may be of different material to the metal insert used to establish electrical connection between the conductors. The barbed insert may be provided within the metal insert or may be provided within the heat shrinkable sleeve separately from the metal insert. In a particularly preferred embodiment of the present invention the metal insert comprises a cylindrical outer wall divided into the first and second conductor receiving means by an elliptical partition positioned at an angle within the cylindrical wall. The partition is at an angle to the axis of the cylinder defined by the outer wall so that the cross sectional area of each receiving means defined by the outer wall and the partition decreases in the direction of insertion of the conductor. The partition is preferably provided with at least one aperture to provide communication between the first and second receiving means so that solder can flow so as to provide a direct connection between conductors in the first and second receiving means. The aperture is preferably provided by means of at least one slot in the partition which allows a portion of the partition to be bent at an angle to the partition, so as to extend towards the rear of the receiving means into which it projects, where the front of the receiving means is defined as the end into which the conductors are inserted. The projections on the partition act as barbs allowing conductors to be inserted into the receiving means but resisting withdrawal of the conductors have been inserted inwardly. Rearwardly extending projections may be provided on the cylindrical outer wall instead of or as well as projections on the partition. Where the partition is provided with portions extending into the two receiving means it may not be practicable to insert a solder blank along one or other faces of the partition. It is therefore preferred to provide the solder blank on the exterior of the metal insert, i.e. on the outer side of the cylindrical wall. It is then necessary to provide apertures in the cylindrical wall to allow the solder, when molten, to pass into the insert and to make contact with conductors inserted into the receiving means. The apertures may be in the form of slots in the outer wall of the insert. Such slots are preferably at an angle to the direction of insertion of conductors. Slots which are parallel to the axis of the cylinder defined by the outer wall may trap conductors, especially stranded conductors, inserted into the receiving means. Thus the slots may for example be at an angle of about 35° to the direction of insertion of conductors into the receiving means into which the slots open. Thus, according to a further aspect of the present invention there is provided a metal insert suitable for use in a wire connector comprising a heat shrinkable sleeve and a solder insert, which metal insert is in the form of a cylindrical outer wall divided into first and second conductor receiving portions by an angled elliptical wall. According to a yet further aspect of the present invention there is provided a metal blank suitable for making a metal insert for use as defined above, which blank comprises a rectangular portion joined to an elliptical portion both provided with slits defining portions bendable into projections. As indicated above the first and second receiving means required for the end to end joining of wires may consist of a single element in the form of a half-cone or a half-quasi cone which is linked head-to-tail to produce the required insert. However where butt connections between wires are required it is possible to use a single element with an appropriately shaped shrinkable sleeve and a solder blank in contact with the element to provide connections between wires inserted from the same side into the receiving means. According to a still further aspect of the present invention there is provided a wire connector for making butt connections between wires, said wire connector comprising a heat shrinkable sleeve, a metal insert within said sleeve for receiving the conductors of wires to be connected, a solder blank within said sleeve disposed so as to flow, when melted, into contact with the metal insert and with the conductors when said conductors are received within the metal insert, wherein the metal insert has a wall defining a hollow half cone or quasi-cone having a base and a flat half side resulting from the bisection of the cone or half quasi cone, said half cone or half quasi cone being open at its base and having a bendable tag at the end opposed to the base, and having at least one opening in its half-side. According to another aspect of the present invention there is provided an electrical connector element having a wall defining a hollow half cone or half quasi- cone for connection to the base of a corresponding element and having at least one opening in its half side. Instead of consisting of two half-cones or half quasi-cones the metal insert may comprise two cones with bases facing in opposed directions lying one above the other. The present invention is particularly suitable for joining together bundles of wires, either as an in-line or as a butt splice. The metal insert is preferably copper or a copper alloy, ferritic stainless steel, or ferro-nickel (Invar), to provide good electrical conduction. Heat shrinkable sleeves of polymeric material for use in making solder connections are well-known and are commercially available, for example from Raychem under trademark SOLDERSLEEVE. There is therefore no need to describe them in detail. Induction heating is a preferred method of directly heating the metal insert and the solder, thus these components are preferably formed from a material suitable for induction heating. The heat-shrinkable sleeve may be shrunk by conduction or radiation from the metal, or by other conventional heating means, such as hot air. The solder blank required for make connection between the wires may be provided as a separate item which is only combined with the metal insert and the heat- shrinkable tube at the time an electrical connection is made. Preferably however the metal insert is provided with the solder already carried on the insert so as to reduce the number of separate items which need to be handled when forming the connection. It is possible to provide the heat shrinkable sleeves with an inner layer of hot melt adhesive. When the sleeve is heated to shrink it the adhesive melts and helps to seal the sleeve to the wires inserted in it. Such adhesives are known and there is therefore no need to describe them here. In a preferred form of the present invention the meltable sealing material is provided as one or more rings carried on the metal insert, for example one mounted at each end of a substantially cylindrical insert. In this way a sleeve can be provided with only two components, namely a heat shrinkable sleeve, and a metal insert carrying both solder and sealing material. This facilitates installation of the sleeve. The invention will now be illustrated by reference to the accompanying drawings in which Figure 1 is a perspective view of a metal insert in accordance with one embodiment of the invention; Figure 2 is a perspective exploded view of another form of metal insert according to the invention showing solder pellets; Figure 3 is a perspective view of a wire connector according to the invention using the metal insert of Figures 1 and 2; with the heat shrinkable sleeve partially cut away; Figure 4 is a side elevation in cross section of another embodiment of a connector according to the invention; Figure 5 is a side elevation in cross section of a single receiving means as used in the connector of Figure 4; Figure 6 is an end elevation looking from the wider end of the receiving means of Figure 5; Figure 7 is a side elevation in cross-section showing a butt connector having a single receiving means (as shown in Figures 5 and 6); Figure 8 is a side elevation, corresponding to Figure 4 but with two sealing rings carried by the metal insert; Figure 9 is a side elevation in cross-section corresponding to Figure 7 but with a sealing ring carried on the metal insert; Figure 10 is a perspective view of another wire connector in accordance with the present invention, with the heat shrinkable sleeve shown as being transparent to show details of the metal insert; Figure 11 is a diagramatic cross-sectional elevation (not to scale) of the metal insert (and associated solder and adhesive) of Figure 10 ; and Figure 12 is a plan view of a metal blank suitable for making a metal insert according to Figure 11. Referring to Figure 1, a metal insert 1 comprises two conductor receiving means 2, 3. The cross-sectional area, of generally rectangular configuration, for receiving conductors of receiving means 2 decreases from front to back, while the cross sectional area of receiving means 3 decreases from back to front. An opening 4 is present in the junction between the two conductor receiving means. An alternative form of insert is shown in figure 2. In this the two receiving means are in the form of half cones. The opening between the two receiving means can be closed by the insertion of solder blanks 5, 6, shaped so as to fit within the receiving means 2, 3. Figure 3 shows an insert as shown in figure 2 in place within a heat shrinkable sleeve 7. The sleeve has an insert 8 of hot melt adhesive towards each end thereof, beyond the metal insert. Two bundles 9 10 of insulated wires are inserted into the opposed ends of the sleeve 7. The insulation is cut away from the ends of the wires to expose bundles of conductors 11 12. To install the wires in the connector the wires are pushed in so that the conductors enter the wide end of the receiving means facing the respective bundle of wires. As the conductors are pushed into the receiving means they are compressed against the inner half of the receiver means, where it abuts on to the other receiving means, and against the solder blank, which blocks the opening between the receiving means. The compression of the conductors within the receiving means helps to retain the bundle of wires in the sleeve prior to the heating of the sleeve to shrink it and also allows pre-contact for checking electrical continuity between the conductors before shrinkage of the outer sleeve. Heating of the connector is now carried out to shrink the sleeve and to melt the solder to bond the conductors to the metal insert and to each other through the opening between the receiving means. There is a considerable degree of overlap between the conductors which facilitates a good electrical connection by means of the solder. The adhesive inserts 8 melt and flow when the sleeve is heated and help to seal the sleeve to the cables and to eliminate water ingress to the electrical connection. It is, of course, possible to omit the adhesive inserts if this sealing of the sleeve is not required. A wire connector according to the invention with an alternative form of metal insert is shown in figure 4. This metal insert 1 comprises two parts 2, 3 which can be joined together, with a solder blank 5 being sandwiched between them. The two parts 2, 3 constitute receiving means for electrical conductors. The two receiving means 2, 3 each consist of an identical metal part which is shown in cross-sectional side elevation in figure 5 and in end elevation, looking from the wider end, in figure 6. The receiving means comprises a flat metal base 13 with an opening 14 running along a major part of the length of the base 13. The base terminates at its narrow end with a tag 15. This is shown as extending downwardly from the base but can be bent round as shown in figure 4 to grip another receiving means to form a two part metal insert for an end-to-end wire connector. A solder blank is inserted between the two receiving means before they are joined together. It is a preferred feature of the insert that the solder blank is shaped to extend laterally beyond at least part of each receiving means when the receiving means are joined together. Thus if the solder blank is made in the form of a rectangular sheet with width corresponding to the widest part of each receiving means it will extend beyond the insert in its central portion. If sufficient heat is applied to shrink the sleeve and melt the solder the sleeve will shrink to fit the metal insert. If insufficient heat is supplied to melt the solder then the projecting edge of the solder blank will be visible through the sleeve. Such a blank can thus act as an indicator of when to terminate the heating process. The individual receiving means are provided with fingers or tabs 16 formed by bending portions of the wall of the receiving means inwardly so as to leave openings 17. The tab 16 have sufficient resilience to allow conductors to be forced past them into the receiving means, then act so as to help to hold the conductors in place before heat is applied to shrink the sleeve. The individual receiving means as shown in figures 5 and 6 have the advantage that they can be used singly to make butt connections between wires, i.e. connections in which the wires are inserted into the connector from the same direction. When used in a butt connection the solder blank will usually be inserted inside the receiving means so as to lie along the base. The tag 15 is bent parallel to the base of the receiving means and a heat shrinkable sleeve is inserted around the receiving means. The sleeve may be preshaped so as to fit the receiving means before the final shrinking and solder melting steps. Figure 7 shows a butt end wire connector using a receiving means in accordance with the invention prior to insertion of the wires to be joined. An alternative sleeve according to the invention for use in in-line connection is shown in Figure 8. The metal insert is the same as that shown in Figures 4, 5 and 6. The insert carries rings of sealing material 8. These are an interference fit on the ends of the insert so that the insert and sealing material can be handled as a unit e.g. for insertion in the heat shrinkable sleeve 7. When the connector is heated the sealing material melts and seals the wires in the connector. Figure 9 shows the corresponding arrangement for a butt end (side-by-side) connector. Referring to Figure 10 and 11 a metal insert 21 comprises a cylindrical outer wall 22 which is divided into first and second conductor receiving means 23, 24 by an angled partition 25. The central portion of outer wall 22 is provided with angled slots 25. A ring of solder 27 surrounds the slots on the outside of wall 22. Rings of adhesive 28 are mounted on the ends of inserts 21 and extend outwardly beyond the insert 21. A sleeve 29 of heat-shrinkable material surrounds the insert. Inwardly extending projections 30 are formed in the wall 22 which extend inwardly (towards the axis of the insert) and rearwardly (away from the direction of insertion of conductors) adjacent each end of the wall. The partition 24 is elliptical in shape and is also provided with projections 31 extending inwardly and rearwardly into respective conductor receiving means. Figure 12 shows a metal blank suitable for forming the metal insert of Figures 1 and 2. The blank comprises a generally rectangular portion 32 which when rolled up will form the outer wall 22 of insert 21. A plurality of cuts 33 adjacent opposed edges of the blank define tongues 34 from which the projections 30 can be formed. A plurality of slots 35, only one of which is shown, are provided at an angle of 35° to the axis of the cylindrical portion of the blank. These slots correspond to slots 26 in the insert 21. Attached to the rectangular portion of the metal blank is an elliptical portion 36 which corresponds to the partition 25. The portion 36 has a plurality of slots 37, 38 therein. The metal left between each pair of slots 37, 38 can be bent to form the projections 31 of the partition 25.

Claims: CLAIMS: 1. A wire connector for making in-line connections between wires, said wire connector comprising a heat shrinkable sleeve, a metal insert within said sleeve for receiving the conductors of wires to be connected, a solder blank within said sleeve disposed so as to flow, when melted, into contact with the metal insert and with the conductors when said conductors are received within the metal insert, wherein the metal insert comprises first and second conductor receiving means for receiving at least one first and at least one second conductor of at least one first and at least one second wire inserted from first and second ends of the sleeve respectively, the first and second receiving means defining openings decreasing in the direction of insertion of the first and second conductors respectively, said first and second receiving means being so disposed that parts of the first and second conductors overlap within the sleeve. 2. A connector according to claim 1 , wherein the first and second conductor receiving means are so shaped that when the solder is melted a direct conductor-to- conductor contact is obtained by means of the solder. 3. A connector according to claim 1 or claim 2, wherein the first and second receiving means are of substantially the same shape and are aligned one above the other so as to present cable receiving openings facing in opposed directions. 4. A connector according to any one of the preceding claims wherein the metal insert comprises two hollow half cones having a base, and a flat half side resulting from bisection of the cone, with the bases facing in opposite directions and the flat half sides in contact. 5. A connector according to any one of claims 1 to 3, wherein the metal insert comprises two hollow half cones having a base and a flat side resulting from the bisection of the quasi cone with the bases facing in opposite directions and the flat half sides in contact. 6. A connector according to claim 4 or claim 5, wherein the two receiving means are in communication with each other through at least one aperture in the half side of each receiving means. 7. A connector according to claim 6, wherein the solder blank is in contact with the said aperture. 8. A connector according to any one of the preceding claims wherein the metal insert comprises two separate substantially identical components having means for holding each other in head-to-tail relationship. 9. A connector according to claim 8 wherein a solder blank is held between the two conductor receiving means. 10. A connector according to claim 9 wherein the solder blank is so shaped as to extend outwardly from a waisted portion of the metal insert resulting from head-to-tail superposition of the first and second receiving means. 11. A connector according to any one of the preceding claims wherein the receiving means has projections extending into the space for receiving conductors. 12. A connector according to any one of claims 1 , 2 and 3, wherein the metal insert comprises a cylindrical outer wall divided into the first and second conductor means by an elliptical partition positioned at an angle within the cylindrical wall. 13. A connector according to claim 12, wherein the partition is provided with at least one aperture to provide communication between first and second receiving means so that solder can flow to provide a direct electrical connection between conductors in the first and second receiving means. 14. A connector according to claim 13, wherein the aperture is provided by means of a slot in the partition enabling a portion of the partition to be bent at an angle to the partition. 15. A connector according to any one of the preceding claims wherein solder is located outside the metal insert and slots are provided in the wall through which the solder can pass when molten, said slots being at an angle to the direction of insertion of the wires. 16. A wire connector for making butt connections between wires, said wire connector comprising a heat shrinkable sleeve, a metal insert within said sleeve for receiving the conductors of wires to be connected, a solder blank within said sleeve disposed so as to flow, when melted, into contact with the metal insert, wherein the metal insert has a wall defining a hollow half cone or half quasi-cone having a base, and a flat half side resulting from bisection of the cone or quasi-cone, said half cone or half quasi-cone being open at its base, and having a bendable tag at the end opposed to the base, and having at least one opening in its half side. 17. An electrical connector element having a wall defining a hollow half-cone or half quasi-cone having a base, and a flat half side resulting from bisection of the cone of quasi-cone, said half cone or half quasi-cone being open at its base and having a bendable tag at the end opposed to the base, and having at least the opening in its half side. 18. A metal insert suitable for use in a wire connector comprising a heat shrinkable sleeve and a solder insert, wherein said metal insert is in the form of a cylindrical outer wall divided into first and second conductor receiving portions by an angled elliptical wall. 19. A metal blank suitable for making a metal insert for use in a wire connector comprising a heat shrinkable sleeve and a solder insert, said blank comprising a rectangular portion and an elliptical potion, both provided with slots defining portions bendable into projections.

Inventors: BRIENS SYLVAIN, DELALLE JACQUES, DELAMOTTE JEAN-CHRISTIAN, DIDOLLA PATRICK, BRIENS, SYLVAIN, DELALLE, JACQUES, DELAMOTTE, JEAN-CHRISTIAN, DIDOLLA, PATRICK
Applicants: BRIENS SYLVAIN, DELALLE JACQUES, DELAMOTTE JEAN CHRISTIAN, DIDOLLA PATRICK, RAYCHEM LTD, RAYCHEM SA NV, BRIENS, SYLVAIN, DELALLE, JACQUES, DELAMOTTE, JEAN-CHRISTIAN, DIDOLLA, PATRICK, RAYCHEM LIMITED, RAYCHEM S.A.
Application year: 1995
Main classification: H01R4
IPC codes: H01R4, H01R43