METHOD AND APPARATUS FOR TWIST CONNECTING WIRES

Abstract: A method of forming an interlocking spiral twist connection between two ductile wires (28, 29) where the method comprising the steps of providing relative rotation between the two members (201, 202) of a two member connector after positioning the wires (28, 29) in side by side relationship in cavity means in both of the members (201, 202), the cavity means having a configuration such that the wires (28, 29) can only be entered into the cavity means in side by side relationship when they are in a specific orientation relative to the cavity means, the relative rotation of the members causing each wire (28, 29) to be jammed against internal surfaces of its associated cavity and during the continuance of said relative rotation maintaining both a braking effect on said wires (28, 29) to control relative longitudinal movement therebetween and a converging force on said members (201, 202).

Description: METHOD AND APPARATUS FOR TWIST CONNECTING WIRES This invention relates to the joining together of two elongated ductile elements (hereinafter called wires) by means of a spiral twist connection between the wires. The invention is concerned with the novel method of achieving the twist tie and apparatus in the form of a connector for performing the method. The invention has particular relevance to joining the conductive cores of insulated electrical cables, which are to be considered as falling within the group of elements to be called "wires" . In conceptual terms the method of the invention comprises positioning wires to be joined in side by side relationship in two members and then applying a twisting torque to the wires by means of relative rotational motion of the members and at the same time applying a brake against relative longitudinal movement of the wires and applying a converging force to the members in the longitudinal direction of the wires during the contra-rotation of the members. In order to carry out the method there is provided a connector which conceptually comprises two relatively rotatable members with cavity means in each member to receive wires to be joined in side by side relationship and in operative relationship with torque applying shoulder means to engage all wires to convert relative rotational movement of the members into a twisting torque which is resisted by torque reaction shoulder means which is engaged by all wires during the application of torque, and with brake means to brake relative longitudinal movement of the wires during the application of torque .-to form a twist connection between the wires. With the twist joining of wires (including the conductors of electrical cables) it is possible manually to twist together the ends of two or more wires to form a dead end connection or an inline connection. However, manual twisting frequently results in a poor connection because of the difficulty in applying sufficient pressure manually to make the joint firm. Frequently the connection provided is in the form of one wire twisted around the other which is a poor form of joint. In the ideal joint each wire is in the form of a spiral which interlocks with a spiral formed in the other wire(s) to give a conjoining of the wires as interlocked spirals. Frequently tools are used to ensure the twisted connection is secure, for example pliers are commonly used by both electrical tradesmen and handymen to grip the ends of the conductors in order to make a twist joint. The torque applied by the twisting of the pliers has to be countered and this frequently requires the wires adjacent the portions being twisted also to be held with pliers. Such an operation requires the necessary two tools to be at hand and for wire insulation strippers to be at hand, if the wires are insulation clad. With such an operation the person making the twist joint has to handle several items at the one time. The task can be achieved but there is considerable tool use and manual dexterity required and a tight joint does not always result. Another drawback with the use of hand tools of the above type for forming the joint is that severe metal deformation can be caused in the wires by excessive twisting or they can be damaged by the use of excess pressure. The present invention provides a simple method and apparatus for achieving a uniformly twisted joint between wires. The multi-part connector of the invention in one of its possible forms can be used to strip the insulation from the wires (conductors) of an electrical cable prior to joining the wires. After joining the wires the connector, in one of its forms, can seal and insulate the connection. Broadly stated the invention is a method of forming a twist connection between two ductile wires as hereinbefore defined, said method comprising the steps of: providing a connector comprised of two members where: (a) each member has wire receiving cavity means to receive wires to be joined in side by side relationshi , (b) each member has torque applying shoulder means in each cavity means, (c) each member has torque reaction shoulder means in each cavity means, (d) at least one member has brake means associated with its cavity means. contra-rotating said members with wires positioned in said cavity means whilst applying converging forces to the members in the longitudinal direction of the wires to be joined to cause said wires sequentially: (i) to be forced into contact with said torque reaction shoulder means by said torque applying shoulder means, (ii) to be braked against relative longitudinal movement during said contra-rotation, (iii) to engage each with the other (iv) to twist each about the other to form interlocking spirals, The invention further provides a connector to carry out the above method where said connector comprises two members each having cavity means accessible from first ends of the respective members to receive and position wires to be joined in side by side relationship, torque applying shoulder means and torque reaction shoulder means in each cavity means adjacent the first ends of the associated member and brake means associated with the cavity means of at least one member. Several presently preferred forms of connector to carry out the method of the invention will now be described with reference to the accompanying drawings in which: Fig.l illustrates a plan view of a connector member as modified by the addition of a means for stripping insulation from electrical conductors; Fig.2 is a front elevational view of Fig.l; Fig.3 is a rear elevational view of Fig.l; Fig.4 is a partly sectioned elevation of two such members as c shown in Fig.l, coupled together in face to face abutment in order to produce inline connections; Fig.5 is an enlarged fragmentary view of a coupling between the connector members of Fig.4 to permit relative rotational movement therebetween; 10 Fig.6 is an end view of a connector intended for connections of non insulated wires and therefore excluding insulation stripping means and illustrating the formation of dogleg torque applying shoulder means; Fig.7 is a sectioned elevation of Fig.6; j ς Fig.8 is an end view of a connector illustrating variations in the internal configuration to form straight torque applying shoulder means; Fig.9 is a sectional elevation of Fig.8; Fig.10 is an isometric view of a preferred member of the 20 connector of this invention to illustrate the obliquely rearward divergent projection of the straight shoulder means of Figs. 8 and 9, wherein such dispositions are nominated to be positive shoulder means; Fig.11 is an isometric view of a further preferred member of 25 the connector of this invention to illustrate obliquely rearward convergent shoulder means shown in Figs.2- , 12-16, wherein such dispositions are nominated to be negative shoulder means; Fig.12 is a sectioned elevation of a pair of opposed connector members of one embodiment with wires mounted therein preparatory to the commencement of relative rotation between the members to form a twist connection between the wires; Fig.13 is a view similar to Fig.12 wherein members are coupled together with a connecting sleeve and illustrating an initial stage in the twist connection of wires; Fig.14 is a sectional view through the plane 14-14 of Fig.13; Fig.15 is a view similar to Fig.13 after the twist connection of the wires is complete; Fig.16 is a view similar to Fig. 13 illustrating the initial stage of twist connection between two insulated wires, the connector members being modified by the addition of the insulation stripping means; Fig.17 is a sectional elevation of a variation of the invention for the formation of a dead end connection between wires; Fig.18 is an end view of one of the members of the connector of Fig.17, featuring an alternative bayonet coupling means; Fig.19 is an elevation of one member of the connector variation of Fig.17, showing details of the bayonet lugs and corresponding mating face of the coupling means; Fig.20 is a sectional elevation showing an early stage of the formation of a dead end twist connection between wires using the connector variation of Fig.17; Fig.21 is a view similar to Fig.20, showing the dead end connection complete and the members coupled together; Fig.22 is an isometric view of a further embodiment of a connector which can be used to perform the method of the invention; Fig.23 is an isometric view of the connector of Fig.22, wherein wires to be connected are mounted in the members preparatory to the formation of a twist connection therebetween; Fig.24 is a view similar to Fig.23 after the twist connection between the wires is complete; Fig.25 is a partly sectioned isometric view of the coupled members of a connector embodying a simple cavity arrangement which will perform the method of this invention; Fig.26 is a view upon the plane 26-26 of the Fig.25 showing wires to be joined positioned in the cavity in side by side relationship in the plane of the primary dimension of the cavity; Fig.27 is an enlarged, sectioned, fragmentary view of the cavity of Fig.26 showing in ghosted lines possible relative positioning of the wires prior to relative rotation of the connector members and Fig.28 is a sectioned elevation of conjoined members showing interengaged teeth means on opposed front faces of the members to permit relative rotation in one direction only. The Fig.4 connector is comprised of two identical members 1 and 2 each having a body 3 which is wider than it is thick and at one end of the body 3 there is a head 4 of - 6 - circular cross-section having a collar 5 also of circular cross-section at the forward end thereof. The collar 5 has an annular front end face 6 with a conical face 7 extending outwardly and rearwardly from the end face 6 and terminating in an engagement shoulder 8, which is preferably angled rearwardly as shown. The two members 1 and 2 are coupled by a sleeve 9 which is generally annular in shape with inwardly directed circular ribs 10 inward of outwardly expanding conical contact faces 11. The internal diameter of the ribs 10 is less than the external diameter of the engagement shoulder 8 and thus there is an interference engagement between the inner faces 12 of the ribs 10 and the shoulders 8 which is facilitated by the engaging action of the faces 7 and 11 as the members 1 and 2 are pushed together with the sleeve 9 therebetween. As will be understood another form of connection would be to mount the sleeve 9 on one member 1 or 2 and then insert the collar of the other member into the sleeve. In an alternative arrangement the collar would be integral with one of the members 1 or 2 and would be profiled internally as just described to snap engage over the shoulder 8 of the other member. The sleeve 9 may also be resiliently deflectable to permit engagement with the collars 5. The construction of the components from a suitably elastic plastics material is envisaged so as to provide for the required ability to deflect resiliently and achieve a snap connection. The foregoing is the preferred form of engagement between the collars and the sleeve as it forms a seal to prevent the ingress of moisture or corrosive agents which could affect the joint. The seal is formed by virtue of the residual forces within the expanded sleeve causing it to bear on the annular ridge 8, Figs.4 and 5, to form a high pressure low contact area along a narrow line of contact. P = f/a, where "P" equals pressure, "f" equals force exerted and "a" equals the area on which the force is exerted. If "a" is small, the result of a narrow line of contact, the force is high and a good seal results. However an alternate arrangement may be used, for example forwardly of the collar 5 may be made up of a plurality of fingers to facilitate the snap connection, or the sleeve ends may be longitudinally slit to provide fingers, thereby to facilitate the snap connection. It will be noted that when the sleeve 9 is in the operative position illustrated the end faces 6 of the members i and 2 are in substantial abutting relationship. The foregoing construction permits the relative rotation of the members 1 and 2 as is required in one manner of performing the method of the invention. However, the relative rotation of the members 1 and 2 whilst interconnected is not essential for the performance of the method of the invention, as will hereinafter be described, and accordingly the collars and sleeve can be other than circular in shape. In one embodiment of the invention where the members 1 and 2 are relatively rotatable the faces 6 are provided with teeth to position the members in a relative rotational position. In a further arrangement the teeth are of ratchet type allowing only one direction of relative rotational movement of one member relative to the other. The reason is to prevent the unwinding of a wire joint after its formation. Internally the members I and 2 are substantially identical and include an axial cavity means configured to have a central opening 14 therethrough from the end face 6 to the rear end face 16 and at least one side opening 15 which may be channel shaped, adjoining the opening 14. The channel 15 may extend through the rear face 16 or may be blind, but is open to the front end of the members 1 and 2. As illustrated in Fig.4, the channel 15 is blind at the rear end 17 and is vee shaped in cross section, but other shapes are also possible. In a further embodiment of the invention to be described later with reference to Fig.18, the channel 15 is interconnected with the opening 14 by a slot the gap of which is less than the diameter of the wire to be joined with the wire in the opening but in the embodiment of Fig.4 the channel 15, where it adjoins the opening 14, has a width in excess of the diameter of the wire to be housed in the channel 15. A better understanding of the interaction of the components forming the snap connection can be obtained from the enlarged fragmentary view Fig.5. Referring now to Figs.6 to 9, these Figs, provide details of some possible configurations of the front end of - li ¬ the channel 15. In Figs.6 to 9 the counterbore 18 of the head 4 is parallel. The counterbore 18 can however be profiled as indicated 19 in Fig.4 and in Fig.11. A curved profile as shown 19 in Fig.4 provides different characteristics for features of the design from those which result from a parallel counterbore 18, these aspects will be discussed later but do not change the functioning of the device. They are best compared by reference to Figs.10 and 11. n Figs.6 to 9 the central opening 14 is identified and it is shown that the channels 15 may be of various Vee configurations which have different channel bottom shapes which serve only to produce a more constant wall thickness 40 (compare with 41). For example in Fig.6 (left side) the Vee bottom 20 is a moderate radius aligned with the periphery of the counterbore 18 and the sides of the Vee channel diverge at an included angle of 30 degrees to intersect with the periphery of the opening 14 at the points 21. There is a conical end enlargement 22 for the channel 15 which produces an intersection profile where the enlargement meets with the opening 14 and ' the channel 15. The intersection profile will hereinafter be called a torque applying shoulder means (SM) , a feature which plays a part in the preferred mode of functioning of the device. In the arrangement involving the channel bottom 20 the conical enlargement 22 has an axis location and maximum radius which cause the maximum radius to align with the vee bottom 20 and for it to intersect with the opening 14 at the points 23, spaced from the points 21. The conical enlargement 22 will intersect with the walls of the Vee channel at the points 24 (see Fig.7). The line 23-21-24 is dog legged, as shown clearly in Fig.7 and.- is the (SM) for this arrangement. In Fig.6 to 9 other possible configurations are illustrated each resulting in a shoulder means (SM) . In Fig.6 (right side) in relation to the channel bottom 25 the shoulder means is shown as the profile 23-21-24 also. In the arrangement with the channel bottoms 26 and 27, Figs.8 and 9 (left and right side), the angles of the channels 15 and the axial location of the conical enlargements 22, are chosen so that the points 23-21 coincide. Thus the shoulder means (SM) in the Figs.8 and 9 are straight line shoulder means (SM) indicated 23/21-24. With all of the foregoing the shoulder means (SM) lie at forwardly convergent angles to the axis of the opening 14 and thus form what will be called positive (SM) , this can readily be seen from the isometric view of Fig.10. Where a profiled counterbore 19 for the head 4 is provided the junctions between the internal curved profile of the head and the ends 20,25,26 and 27 of the channels 15 will be curved. In Fig.11 there is illustrated in isometric a typical intersection wherein the shoulder means are indicated (SM) . Which (SM) is effective depends on the rotation direction. These shoulder means lie at forwardly diverging angles to the axis of the opening 14 and are called negative shoulder means (SM) . The formation of the twist joint broadly involves the mounting of alternate wires through the members I and 2 respectively and continuing into or through the second member respectively as illustrated in Fig.12, then provide relative rotational motion for the members which may be in the form of contra-rotation. As will be understood a twist joint to be effective must be a tight joint, this is particularly so with twist joints for electrical wires. The achievement of a tight twist joint involves certain considerations as will become clear from the following description, the principal objective being to provide conjoined interlocking spirals, one such consideration is the application of converging forces on the members during the formation of the twist connection. Referring to Fig.12 and assuming the "wires" are of single strand copper (or like) form. Holding portions 28 and 29 of the two wires 30 and 31 are housed respectively i the openings 14 of the members 1 and 2 and joining portions 32 and 33 of the respective wires 30 and 31 are entered into the channels 15. It will be noted that the opening 14 is larger than the diameter of each wire but less than the aggregate of the diameters of both wires. This is intentional as there is a phase in the creation of the twist tie between the wires where they are forced one over the other in overlapping relationship within the opening 14 by grip promoting means in the form of the shoulder means (SM), requiring deformation of the member, which for this reason must be of a deformable nature. Reference in this description to "means for gripping a wire" is intended to indicate a means to brake the wires being connected against relative longitudinal movement during the formation of the joint. The term "brake" is intended to mean either: a movement inhibiting force which can be overcome or a movement preventing force. Initial contra-rotational movement of the members 1 and 2 will cause first contact parts 34 and 35 of the wires 30 and 31 lying forward of the channel and opening ends to contact, see Fig.13 and Fig.14 which is a sectional end elevation on the section line 14-14 of Fig.13. It is at this stage that an overlapping engagement of the wires in the opening 14 needs to be promoted. This is achieved by the combined effects of the contra-rotation and the shoulder means (SM) previously described applying torque to the wires and forcing the wires against torque reaction shoulder means in the wire receiving openings. Without the shoulder means (SM) the wires in the channels would tend to withdraw longitudinally from the channels in response to initial relative rotation between the members 1 and 2 resulting in substantially no angular disposition of wires in opening 14 and channel 15 one relative to the other, which is an essential relationship for a spiral twist to be achieved. The overlapping within the opening 14 is essential (in this embodiment of the invention) to promote the frictional drag brake effect referred to above across the shoulder means (SM) . Experimentation has shown that unless a braking effect is present during the twisting operation a twist of acceptable tightness and spiral form will not occur. It is desirable that the braking effect is equal to or greater in force than the physical resistance in the wires in consequence of their reaction to the reforming forces exerted upon them by the shoulder means. Experimental results also indicate that an applied or consequential braking effect on each wire at both ends of the forming joint is preferred. This invention insofar as it encompasses a braking effect relates not so much to the provision of the braking effect (which is an essential component for effecting any spirally twisted joint) as to the manner in which the braking effect upon each wire is achieved. At this time the members 1 and 2 need not be joined by the sleeve 9 (see Fig.12) , although if desired the members 1 and 2 can be laterally moved to be axially aligned (with corresponding bending of the wires 30 and 31) and be joined by the sieeve 9, see Fig.13. As explained previously the form of the collar to sleeve connections will allow contra-rotation of the members 1 and 2 whilst coupled by the sleeve. Whether the offset arrangement of Fig.12 or the aligned arrangement of Fig.13 is used the initial stages of the twist formation will be substantially the same. Referring to Fig.13 it will be seen that initial contact has been made between the contact parts 34 and 35 as the first twist is being formed. Fig.14 is a sectional view through the plane 14-14 and shows the relationship of the contact parts 34 and 35 at this stage of the contra-rotational sequence of the members 1 and 2. The plane line A'-A' defines a plane of the assembly which coincides with the existent point of contact between the joining portion 32 of the wire 30 and the converging shoulder means (SM) and is included to illustrate the effect of the shoulder means (SM) upon the joining portion 32 to wedge it into an interference fit with the holding portion 29 of the wire 31 in the restricted opening 14. The wire 29 is thereby also wedged against the inner face of the opening 14 which face provides an abutment shoulder or torque reaction shoulder to resist the forces applied by the shoulder means (SM) . The existent relative cross-sectional positions of the portions 29 and 32 in and to the opening 14 in the plane A-A, is shown in Fig.14 by the dotted sectional lines 29(A) and 32(A). Contra rotation continues until a tight twist of suitable length is formed or until the free ends of the wires exit the channels 15. The final form twist connection is shown in Fig.15, in which the member 2 is rotated 180 degrees further relative to the member 1 that is shown in the arrangement of Fig.13 for uninsulated wire. The foregoing twist operation can also be performed with insulated conductors. In such cases the insulation covering is stripped from the joining portions 32 and 33 of said conductors and they are entered respectively through the openings 14 of the members 1 and 2 and into the channels 15 of the other members, in an arrangement similar to that illustrated in Fig.12. The openings 14 are again smaller in diameter than the aggregate of the diameters of the insulated conductor and the bared conductor covering so that when the overlapping of the adjacent insulated and bared conductor takes place in the opening 14 they become wedged in the openings and cause the bared conductors to bite into the insulation of the adjacent wires thereby providing the frictional drag brake effect required for proper twist formation, see Fig.16. In a variation of the invention the same principles can be used for dead end connections. In this regard reference to Figs.17 to 21 show how this can be achieved. A different principle for promoting frictional drag brake effects is used in this arrangement . Referring to Fig.18 which is an end view of the member 101, the openings of the previous embodiment are modified in this embodiment and comprise a blind central opening 103 connected by discrete radial slots 104 to two discrete radially offset blind ended chambers 105. The gap of the slots 104 is narrower than the diameter of the wire to be housed therein. Provision of a conical enlargement 106 at the open end of each chamber 105, correspondingly produces a convergent entrance 107 leading into the open end of each said slot 104 which results in the formation of profiled shoulder means (SM) between the points 108-109-110 in relation to each chamber 105., in similar fashion to that described in the foregoing for Figs. 6 to 9. In a twist operation (see Figs.17, 20 and 21) the holding portions 111-112 of the wires 113-114 are held in spaced relationship in openings 115 in the member 102 and the respective joining portions 116-117 of said wires reside in the chambers 105 of the member 101. Resistance of the wires to deformation when the members 101 and 102 are contra rotated, bring said joining portions into contact with the profiled shoulder means (SM) 108-109-110 which guide the joining portions into the convergent entrances 107 and thereafter, into engagement with the restrictive slots 104 thereby to generate a frictional braking effect thereupon. In combination with the continuing relative rotation between the members 101 and 102, the said braking effect causes the joining portions 116-117 to overlap and contact at intermediate portions 118-119 of said joining portions, in commencement of a twist connection between the said joining portions, which in response to further relative rotation between the said members, culminates in the formation of a tightly conjoined spiral dead end joint between said joining portions 116-117 of the wires 113-114 (see Fig.21). After completing the joint, it is housed in the blind central opening 103 in the member 101 and the members 101 and 102 are united in face to face contact by means of headed lugs 120 common to both members. The heads of said lugs may be profiled to suit co-operative engagement with corresponding surfaces upon each member, in either a snap connection or by a cammed bayonet connection. With reference to Figs. 17 to 21 the headed lugs illustrated are intended to perform the bayonet type connection referred to, whereby a tight engagement of the raised lands 125 is accomplished by passing the headed lugs 120 of the respective members 101 and 102 through respective apertures 123 in opposing said members in order to bring the said lands of opposed members 101 and 102 into radially misaligned face to face contact, then contra rotating said members (30 degrees as illustrated) , simultaneously to align the lands whilst forcing them into tight engagement by virtue of the reaction between correspondingly profiled camming surfaces, being respectively the inner edges 121 of the elevated head portions 122 of the headed lugs 120, and the rearwardly facing outwardly disposed surfaces 124 in the apertures 123. Alternatively, the members may be provided with collars 5 and coupled together with a sleeve 9 (as seen in Fig.4) prior to commencement of the twist connection, whereby the joining portions 116 and 117 of the wires 113 and 114 to be joined, are dragged through the restricted radial slots 104 from the chambers 105 as contra rotation of the members 101 and 102 begins, thereafter to progressively transfer into the central opening 103 and said joining portions 116 and 117 spirally conjoin towards the blind bottom of said central opening 103 during the continued contra rotation of the members 101 and 102; and whereby the interference fit of said joining portions in the slots 104 imposes a frictional grip upon each said joining portion as they drag through said slots, thereby to maintain the required braking effect to both wires to ensure a tightly twisted spiral joint. Other forms of end to end connection could also be provided as might be preferred for particular configurations of the members 1 and 2/101 and 102. In a further variation of in-line connections, the braking arrangement to provide the frictional drag needed to ensure a tightly twisted connection as described in the foregoing, may be modified so that the brake effect can be total. With reference to Figs. 22 to 24 the opening 14 and adjoining radial extension 15 of Fig.4 are replaced by or have their equivalents in the openings 53-54 in members 51-52 and may be joined by the slots 55. With reference now to Fig.23 it can be seen that as with the foregoing, holding portions 58 and 59, and, 60 and 61, of respective wires 56 and 57 are located in the openings 53 and 54 of the members 51 and 52 and respective joining portions 62 and 63 are subsequently located in between the respective openings 53 and 54 with the free ends 64 and 65 of said joining portions 62 and 63 protruding from the rear ends 66 of the respective members 51 and 52. The brake effect in this embodiment is achieved as follows. The free ends 64 and 65 are bent across the rear ends 66 of the members 51 and 52 in the slots 67 and are then further bent forwardly along the sides of said respective members, in the further slots 68. The resisted bends provide the brake effect by resisting axial movement of the free ends 64 and 65 needed thereby to ensure a tightly twisted connection as said opposed housings are axially contra-rotated. Fig.24 illustrates a final form connection. Other features of the members 1 and 2 which facilitate the use of the connector include an insulation stripper for insulated electrical wires, see Figs. 1,3,4,10,11,16 and 25. It comprises an end extension 36 of the members 1 and 2 preferably coupled thereto by a frangible zone 37. The extension has a slot 38 therealong and a tapered entry 39 to the slot. The edges of the slot 38 and entry 39 are angled to provide a cutting edge 40. The slot 38 ideally is slightly greater in width than the diameter of the conductor of the wire and the tapered entry 39 has a maximum width greater than the diameter of the insulation. The procedure is to place the wire with the required length to be stripped above the extension 36 and then force the insulated wire into and through the tapered entry 39 into the slot 38 preferably with a part or full rotation to cause the cutting edge to sever the insulation. Then by holding the wire and pulling the member 1 away from the wire the severed insulation is stripped from the conductor leaving it bared for insertion into its channel in the member 1. If desired the wire can be inserted into the slots of the extensions of two oppositely opposed relatively inverted members 1 and 2 and then by pulling the members apart the stripping is effected. Either form of stripping can be adopted. Subsequently the extensions 36 can be broken off, if desired. As a further feature of the invention it is desirable to seal the opening 14 around the wire passing therethrough. In Fig.l there is shown an inwardly and forwardly projecting annular sealing flap 42 which will, as can be readily understood, embrace a wire passing through the opening 14. The forward angle of the flap facilitates the passage of the wire through the opening 14. An alternative rear opening seal arrangement is illustrated in Fig.17, 20, 21 and 28. It is preferred when material inflexibility of the moulded member prevents the proper functioning of the flap type seal and when a modified embodiment, utilising a wire to wire overlap, as opposed to a wire to insulation overlap in the openings 14 , is used for electrical wires. The alternative seal relies upon a gradual tapered entry into the through opening in the rear end of the member wherein the minimum diameter cf the entry is less than the insulation diameter of the wire. The insulation is pushed into the tapered entry as far as it will go when mounting the wire in the member. Thereafter the formation of the spiral joint draws upon this portion of the wire, dragging the insulated shrouding tightly into the tapered entry thus forming a watertight seal. For electrical conductors the members can be formed from material which can be moulded and which has appropriate heat and electrical insulation properties. The material should also be sufficiently hard to allow the cutting edges of the slot and entry thereto, 38-39, to sever the insulation around a conductor. A typical material would be glass filled PET, such as DuPont "Rynite" (trade mark) grade FR530 and FR515. It will be clear from the several embodiments described that these connectors can have more than one channel associated with the opening 14 in order to join more than two wires in one connection. Other variations can be adopted without departing from the inventive concept and method as hereinbefore defined.

Claims: — i — CLAIMS : 1. A method of forming an interlocking spiral twist connection between two ductile wires where said method comprises the steps of providing relative rotation between the two members of a two member connector after positioning the wires to be joined in side by side relationship in cavity means in both of said members, the configuration of the cavity means in each member being such that each wire is jammed against internal surfaces of its associated cavity means by the relative rotation of said members, and during the continuance of said relative rotation maintaining both a braking effect on said wires to control relative longitudinal movement therebetween and a converging force on said members. 2. A two member connector to forrr. a twist connection between two wires where each member has wire receiving cavity means configured to receive the two wires to be connected in specifically oriented side by side relationship therein such that relative rotation between the members will cause said wires to be jammed against surfaces of the cavity means of the respective members. 3. A method of forming a twist connection between two ductile wires, said method comprising the steps of: providing a connector comprised of two members where: (a) each member has wire receiving cavity means to receive wires to be joined in side by side relationship, (b) each member has torque applying shoulder means in each cavity means, (c) each member has torque reaction shoulder means in each cavity means, (d) at least one member has brake means associated with its cavity means, contra-rotating said members with wires positioned in said cavity means whilst applying converging forces to the members in the longitudinal direction of the wires to be joined to cause said wires sequentially: (i) to be forced into contact with said torque reaction shoulder means by said torque applying shoulder means, (ii) to be braked against relative longitudinal movement during said contra-rotation, (iii) to engage each with the other (iv) to twist each about the other to form a twist connection of interlocking spirals. 4. A connector to form a twist connection between two ductile wires where said connector comprises two members each having cavity means accessible from first ends of the respective members to receive and position wires to be joined in side by side relationship, torque applying shoulder means and torque reaction shoulder means in each cavity means adjacent the first ends of the associated member and brake means associated with the cavity means of at least one member. 5. A connector as claimed in claim 4 wherein at least part of the cavity means of said one member has a cross-sectional configuration with a primary lateral dimension exceeding the aggregate of the diameters of the wires to be joined and a secondary lateral dimension in a direction transverse to the primary dimension which is less than said aggregate thereby to allow entry of the wires in side by side relationship substantially in the plane of said primary dimension, and said torque applying shoulder means and said torque reaction shoulder means are the inner surfaces of said cavity means against which said wires become jammed in consequence of the relative rotation of said members and said brake means is the friction applied by said cavity inner surfaces to said wires in consequence of said jamming during the relative rotation of the members to form a twist joint. 6. A connector as claimed in claim 5 wherein said cavity means includes, a counterbore into said one member from the first end thereof with a first wire housing portion which extends into said one member from said counterbore, a further wire housing portion which is aligned with and connects said first portion to a rear end of said one member and has a cross-sectional configuration preventing both wires passing therethrough. 7. A connector as claimed in claim 6 wherein said first wire housing portion includes two zones interconnected in the direction of the primary lateral dimension, one zone is defined by an arc of a circle greater than 180 degrees and the other zone is defined by two radially outwardly convergent surfaces, chamfers along lines of intersection of said surfaces with said counterbore thereby to provide an enlarged entry end for said other zone and further provide within said first wire housing portion intersection lines between said chamfers and said one zone, said intersection lines constituting said torque applying shoulder means and a component of said brake means acting on said wires. 6. A connector as claimed in any one of claims 4 to 7 wherein both members are as claimed in the claims 4 to 7. 9. A connector as claimed in any one of claims 4 to 8 including a coupling in the form of an extended collar at the first end of a connector member as claimed and said collar has a bore adapted to pass over and releasably resiliently engage with a co-operative annular flange extending from the first end of the other connector member thereby to link the members together. 10. A connector as claimed in any one of claims 4 to 8 including a coupling in the form of a sleeve, a coupling collar at the first end of each of the connector members with which said sleeve is adapted to releasably resiliently engage thereby to link the connector members together. 11. A connector as claimed in claim 9 or claim 10 wherein the coupling permits the members to be relatively rotated whilst linked together. 12. A connector as claimed in claim 11 wherein the members first ends are provided with and are interengaged by detent means when the members are linked together to thereby rotationally position the members, said detent means being able to be forcibly over-ridden during relative rotation of said members. 13. A connector as claimed in claim 12 where said detent means can be over-ridden only in one rotational direction. 14. A connector as claimed in claim 4 wherein the cavity means of said one member includes two zones interconnected in a radial direction and the cross-sectional areas of the zones is such that the two wires to be joined cannot occupy either of said zones simultaneously, and the interconnection between the two zones is a slot means with a gap adjacent each zone less than the diameter of either of said wires, and wherein said torque applying shoulder means and said torque reaction shoulder means are the inner surfaces of said cavity means against which said wires become jammed during the relative rotation of said members and said brake means is the friction applied to said wires as they are forced into the gap of said slot means by the relative rotation of said members during the formation of a twist joint. 15. A connector as claimed in claim 14 including chamfers around entry ends of said zones adjacent said one member first end to provide an enlarged entry end for said zone and further provide within said slot means intersection lines between said chamfers and said slot means, said intersection lines providing said torque applying shoulder means and a component of said brake means acting on said wires. 16. A connector as claimed in claim 14 or claim 15 wherein the other of said members includes a cavity means through which said wires to be joined are passed prior to entry into the cavity means of said one member. 17. A connector as claimed in claim 16 wherein said cavity means comprises two separate openings each having first parts adjacent said first end of the other of said members of a size to allow a bared wire to pass therethrough and second parts of a larger size through the remainder of the other of said member to accept insulation shrouding of said wire, the junction between each opening first and second parts being in the form of a fusto-conical shoulder directed towards said first opening part to apply constricting forces on an end of the insulation shrouding of said wire as said insulation is forced into contact with said fusto-conical shoulder by said wire being drawn into a twist connection with the other wire thereby to seal the insulation against said fusto-conical shoulder and to seal the insulation onto said wire. 18. A connector as claimed in any one of claims 14 to 16 wherein said one member and the other of said members are provided at their first ends respectively with releasable catch means including resilient fingers with latch lugs and openings with co-operating catch lugs. 19. A connector as claimed in any one of claims 14 to 16 wherein said one member and the other of said members are provided at their first ends with fingers with latch lugs and openings with co-operating ramped latch faces so that insertion of said fingers in said openings followed by partial relative rotation of the members will cause engagement of said latch lugs with said latch faces in a camming action pulling said members into abutting relationship. 20. A connector as claimed in claim 19 including sealing surfaces surrounding the cavity access from the first end of both members which surfaces are forced into contact by said camming action. 21. A connector as claimed in claim 20 where the sealing surface on the first end of at least one of said members is a continuous raised land. 22. A connector as claimed in any one of claims 4 to 21 wherein said members are each comprised of two mating pieces adapted to be connected together, thereby to allow said wires to be entered laterally into said cavity means. 23. A connector as claimed in claim 22 wherein the pieces of each member are hinged together so as to be hingedly openable for the entry therein of the wires to be connected. 24. A connector as claimed in any one of claims 4 to 13 including an insulation cutter extending from at least one of said members at an end opposite the first end thereof, said cutter comprising a pair of fingers with a spacing between the first finger portions adjacent said opposite end of said member which is substantially equal to but no less than the diameter of the wire to be mounted in the cavity means of the member and a spacing between further finger portions extending from said first finger portions to free ends of said fingers remote from said first finger portions which is divergent away from said first finger portions, cutting profiles on facing edges of said fingers whereby insulated wires forced between said fingers into the space between said first finger portions and rotated will have the insulation circumferentially severed. 25. A connector as claimed in claim 24 wherein said insulation cutter is frangibly connected to its associated member. 26. A connector as claimed in any one of claims 4 to 25 which includes cavity means with associated torque applying shoulder means, torque reaction shoulder means and brake means for more than two wires to be twist connected. 27. A connector as claimed in claim 6 including in said further wire housing portion a resilient seal to sealingly embrace a wire mounted in said further wire housing portion in an interference relationship.

Inventors: MACKANESS JAMES BELLAMY, PUCHY DAVID WILLIAM PETER, MACKANESS, JAMES, BELLAMY, PUCHY, DAVID, WILLIAM, PETER
Applicants: MACKANESS JAMES BELLAMY, PUCHY DAVID WILLIAM PETER, MACKANESS, JAMES, BELLAMY, PUCHY, DAVID, WILLIAM, PETER
Application year: 1991
Main classification: H01R43
IPC codes: H01R4, H01R43