Patent Publication Number: US-11024984-B2

Title: Contact carrier, electrical contact unit and a method of producing a cable assembly

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of the filing date under 35 U.S.C. § 119(a)-(d) of German Patent Application No. 102017105682.3, filed on Mar. 16, 2017. 
     FIELD OF THE INVENTION 
     The present invention relates to a contact carrier and, more particularly, to a contact carrier of an electrical contact unit. 
     BACKGROUND 
     A large number of electrical connectors are known which transmit electrical currents, voltages, signals and/or data with a large range of currents, voltages, frequencies and/or data rates. In the low, middle or high voltage and/or current ranges, and especially in the automotive industry, such connectors must ensure permanently, repeatedly and/or after a comparatively long service life a transmission of electrical power, signals and/or data without delay in adverse conditions. These adverse conditions can include warm, possibly hot, polluted, humid and/or chemically aggressive environments. Due to a wide range of applications, a large number of specially configured connectors are known. 
     The connector or housing of the connector can be installed on an electrical cable, a conductor, or a cable harness as a cable assembly. The connector or housing can alternatively be installed at an electrical unit or device such as a leadframe or a printed circuit board of an electronic component or mating connector. A connector disposed on a cable is commonly referred to as a plug connector and a connector disposed on an electrical component is a receptacle or socket connector. 
     Connectors corresponding to one another (connectors and mating connectors) usually have fastening or locking arrangements for long-term but releasable fastening or locking of the connector to the mating connector. Corresponding electrical contact elements or terminals must be securely received in the connector. Since the housings of the connectors are usually subject to a certain standardization, such as, for example, the FAKRA standard or a different standard, the most important dimensions of the housings have the same dimensions across different manufacturers. 
     Efforts are made to improve the cost-effective production of connectors, contact devices, and cable assemblies. In the prior art, two different kinds of joining methods, such as adhesive, soldering, or welding and crimping must be applied successively for producing an electrical cable assembly. 
     A two-pole electrical contact unit  80  according to the prior art is shown in  FIGS. 1 and 2 . The two-pole electrical contact unit  80  has a contact carrier  81  and an electrical shield contact device  82 . The contact carrier  81  includes a contact carrier body  100 , at or in which two electrical contact elements  190  or terminals  190  are embedded. The contact carrier body  100  is integrally formed and includes a connecting section  110 , a positioning section  120  or transition section  120 , and a conductor mounting section  180 . 
     The contact elements  190 , as shown in  FIGS. 1 and 2 , extend from the connecting section  110 , in which they comprise contact sections  191 , through the positioning section  120  into the conductor mounting section  180 , in which they comprise cable contact sections. The contact sections  191  are formed as spring contacts or tongue contacts and contact a mating contact element. Other types of contact sections  191  such as, for example, a pin contact, peg contact, tab contact, socket contact or hybrid contact are also possible. The cable contact sections are formed as adhesive, solderable, or weldable cable contact sections. 
     In order to connect the cable contact sections which are embedded in the contact carrier body  100  to stripped longitudinal end sections  433  of two inner conductors  430  of a coaxial cable  40  in an electrically conductive and mechanically fixed manner, the longitudinal end sections  433  of the coaxial cable  40  are adhered, soldered or welded to the mechanical cable contact sections. The conductor mounting section  180  is accessible from the outside, i.e. upwardly open, and the longitudinal end sections  433  of the coaxial cable  40  are inserted in a vertical direction H into the conductor mounting section  180 . The longitudinal end sections  433  of the coaxial cable  40  are then adhered, soldered or welded to the cable contact sections. 
     The contact carrier  81  with the coaxial cable  40  which is fastened thereon can be disposed in a contact carrier receptacle  200  of the shield contact device  82  as shown in  FIG. 2 . The contact carrier receptacle  200  has at least one electrical contact device  202 , e.g. a contact spring  202  or a contact segment  202  for a mating contact unit, and a coding device  204 . 
     The shield contact device  82  is crimped onto the coaxial cable  40 . The shield contact device  82 , as shown in  FIGS. 1 and 2 , has a cover section  280  with two cover wings  282 , a shield crimping section  240  with two crimp flanks  242  and an insulation crimping section  250  with two crimp terminals  252 . During crimping, the cover wings  282  are bent on the cover section and close the upwardly open conductor mounting section  180 ; an outer conductor crimp and an insulation crimp are further established at the shield crimping section  240  and the insulation crimping section  250  as shown in  FIG. 2 . 
     Particularly in the automotive industry, simple, fast and mass-producible joining of cables to contact devices and/or contact units is desirable for an on-board electrical system which includes all electrical and electronic components in vehicles. The current two-part joining methods of electrical connectors and electrical cable assemblies are inefficient and not cost-effective. 
     SUMMARY 
     A contact carrier for an electrical contact device comprises a contact carrier body and a contact element disposed in the contact carrier body. The contact carrier body has a connecting section and a conductor clamping section. The conductor clamping section is substantially closed in a circumferential direction of the contact carrier body and extends along a longitudinal direction of the contact carrier body. The contact element has a contact section extending from the connecting section for contacting a mating contact element. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be described by way of example with reference to the accompanying Figures, of which: 
         FIG. 1  is an exploded perspective view of an electrical contact unit according to the prior art with a coaxial cable; 
         FIG. 2  is a perspective view of an electrical cable assembly according to the prior art with the electrical contact unit and the coaxial cable of  FIG. 1 ; 
         FIG. 3  is a perspective view of a crimpable contact carrier according to an embodiment of the invention; 
         FIG. 4A  is a schematic front view of a contact chamber of the contact carrier of  FIG. 3  with a top wall in a pre-crimped state; 
         FIG. 4B  is a schematic front view of the contact chamber of  FIG. 4A  with the top wall in a crimped state; 
         FIG. 5A  is a schematic front view of a contact chamber of the contact carrier of  FIG. 3  with a top wall in a pre-crimped state; 
         FIG. 5B  is a schematic front view of the contact chamber of  FIG. 5A  with the top wall in a crimped state; 
         FIG. 6  is a sectional perspective view of a contact carrier and a crimped shield contact device according to an embodiment; 
         FIG. 7  is a sectional perspective view of a contact carrier and a crimped shield contact device according to an embodiment; 
         FIG. 8  is a perspective view of an electrical cable assembly according to an embodiment; 
         FIG. 9  is a sectional perspective view of a contact carrier and a crimped shield contact device according to an embodiment; 
         FIG. 10  is perspective view of an electrical cable assembly according to an embodiment; 
         FIG. 11  is a sectional perspective view of the electrical cable assembly of  FIG. 10 ; 
         FIG. 12  is a sectional side view of a contact carrier and a contact element according to an embodiment; 
         FIG. 13  is a sectional perspective view of the contact carrier of  FIG. 12  and a crimped shield contact device; 
         FIG. 14  is a sectional perspective view of a contact carrier and a crimped shield contact device according to an embodiment; 
         FIG. 15  is a sectional perspective view of a contact carrier and a crimped shield contact device according to an embodiment; and 
         FIG. 16  is a sectional perspective view of a contact carrier and a crimped shield contact device according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENT(S) 
     Embodiments of the present invention will be described hereinafter in detail with reference to the attached drawings, wherein like reference numerals refer to the like elements. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided so that the disclosure will be thorough and complete and will fully convey the concept of the invention to those skilled in the art. 
     The following description relates to a crimp contact unit  10  according to the invention being depicted using different features to the prior art mentioned above. Like reference numbers refer to like elements and only the differences from the prior art shown in  FIGS. 1 and 2  will be described in detail herein. 
     A crimpable contact carrier  11  of the crimp contact unit  10  according to an embodiment is shown in  FIGS. 3-5 . The contact carrier  11  has a contact carrier body  100  including an inner conductor clamping section  130  instead of a conductor mounting section  180 . The inner conductor clamping section  130  has at least one contact chamber  139  as shown in  FIGS. 4A-5B . In an embodiment, two side-by-side contact chambers  139  form the inner conductor clamping section  130 . The inner conductor clamping section  130  or the contact chambers  139  are formed substantially closed in the circumferential direction U of the contact carrier  11  along the longitudinal direction L of the contact carrier  11  and. 
     One individual contact chamber  139 , as shown in  FIGS. 4A-5B , has on a base  131  a completely closed base wall  131 , on a side  132  or middle side  133  a completely closed side wall  132  or completely closed middle side wall  133 , and on a ceiling  134  a top wall  134 . The top wall  134  is formed across at least one integral hinge  136  with at least one side wall  132  and/or at least one middle side wall  133 . The top wall  134  can be completely closed, as shown in the embodiment of  FIGS. 3 and 5A , or partially closed, as shown in the embodiment of  FIG. 4A . 
     In an embodiment, the contact carrier  11 , including the top wall  134 , is monolithically formed in a single piece. A materially one-piece contact carrier  11  is intended to be understood to mean a contact carrier  11  which cannot be separated without damaging the contact carrier  11 . In an embodiment, the contact carrier  11  is formed by injection molding. In an embodiment, the contact carrier  11  is formed from a plastic material. 
     If the top wall  134  is completely closed, the top wall  134  has a predetermined breaking point  135  as shown in  FIG. 5A  which extends substantially completely in the longitudinal direction L of the contact chamber  139 . The breaking portion  135  can be disposed laterally on a side wall  132  or middle side wall  133  or centrally as shown in  FIG. 5 . If the top wall  134  is partially closed, as shown in  FIG. 4A , the top wall  134  has a through-slot  135  which extends substantially completely in the longitudinal direction L of the contact chamber  139 . The through-slot  135  can be disposed laterally on a side wall  132  or middle side wall  133  as shown in  FIG. 4A  or centrally. 
     Depending on a configuration of the top wall  134 , the top wall  134  can be formed as an individual wing  134  with a lateral through-slot  135  as shown in  FIG. 4A , as an individual breached wing  134  with a lateral predetermined breaking point  135 , as double breached wings  134  with a middle predetermined breaking point  135  as shown in  FIG. 5A , or as double wings  134  with a middle through-slot  135 . Depending on a configuration of the top wall  134 , a wing with its lateral or middle free edge may be broken free and is movable in the contact chamber  139  with respect to an integral hinge  136 . The chamber  139  is thus deformable as the top wall  134  is movable with respect to the integral hinge  136 . As shown in  FIGS. 4B and 5B , a longitudinal end section  433  of the inner conductor  430  can be mechanically clamped onto a respective cable contact section  193  of the respective contact element  190  by the top wall  134 . 
     The contact chamber  139  or the top wall  134  is deformable or movable by an inner conductor crimping section  230  of a shield contact device  12  as shown in  FIGS. 4A-5B and 8 . The contact carrier  11  is disposed in the shield contact device  12  and the longitudinal end sections  433  of the inner conductor  430  are positioned in the inner conductor clamping section  130  of the contact carrier  11 . 
     As shown in  FIGS. 8 and 10 , the connecting section  110  and the positioning section  120  are positioned in the contact carrier receptacle  200  of the shield contact device  12 . The contact carrier  11  and the shield contact device  12  together form a contact unit  10 . The conductor clamping section  130  is positioned in an inner conductor crimping section  230  of the shield contact device  12 . The inner conductor crimping section  230  has two crimp terminals  232 . The shield contact device  12  also has the shield crimping section  240  with two crimp terminals  242  and the insulation crimping section  250  with two crimp terminals  252 . 
     To position the longitudinal end sections  433  of the inner conductors  430  in the inner conductor clamping section  130 , the longitudinal end sections  433  of the inner conductors  430  must be advanced from behind into the contact chambers  139  substantially linearly in the longitudinal direction L of the contact carrier  11  and the shield contact device  12 . The longitudinal end sections  433  of the inner conductors  430  can then be mechanically clamped onto the cable contact sections of the contact element  190  by crimping. 
     During crimping, the crimping sections  230 ,  240 ,  250  of the shield contact device  12  are substantially simultaneously or partially successively crimped. The inner conductor crimping section  230  of the contact device  12  is crimped onto the conductor clamping section  130  of the contact carrier  11 , the shield crimping section  240  of the contact device  12  is crimped onto an electrical outer conductor  440  and/or a ferrule  400  of the outer conductor  440  of the coaxial cable  40 , and the insulation crimping section  250  of the contact device  12  is crimped onto an electrical outer insulation of the coaxial cable  40 . 
     The two-pole contact unit  10  with a two-pole coaxial cable  40  crimped thereon forms an electrical cable assembly  1  as shown in  FIG. 10 . The crimp contact unit  10  is a straight plug-in sleeve. In other embodiments, the crimp contact unit  10  can be formed in an angled or curved manner, or can be a flat plug-in sleeve, a flat plug, a hermaphrodite contact unit, socket contact unit, tab contact unit, peg contact unit, or pin contact unit etc., with one or a plurality of poles. 
     When crimping the inner conductor crimping section  230  of the contact device  12  onto the conductor clamping section  130  of the contact carrier  11 , the at least one crimp terminal  232  is moved onto the respective top wall  134  such that the top wall  134  begins to move and breaks the predetermined breaking point  135 . The wing, as shown in  FIGS. 4B, 6 and 9 , or the two wings, as shown in  FIGS. 5B, 7, 11 and 13-16 , of the top wall  134  are bent inwardly into the respective contact chamber  139 , where the free edge thereof or the free edges thereof meet on the longitudinal end section  433  of the respective inner conductor  430 . As a result, a crimping connection, clamping connection, press connection, tension connection or squeeze connection etc. is established between the top wall  134 , the longitudinal end section  433  of the respective inner conductor  430  and the respective cable contact section  193  of the contact element  190  by the conductor crimping section  230  of the contact device  12  or an at least one crimp terminal  232 . 
     In an embodiment, in order for the respective crimp terminal  232  to be able to actuate the top wall  134  or the wing or wings, the crimp terminal  232  can have at least one inwardly facing projection  233 ,  234  as shown in  FIGS. 4 and 5 . The at least one inwardly facing projection  233 ,  234  of the crimp terminal  232  can be formed from a wall of the crimp terminal  232  itself, for example, by a corrugation  233  as described below, a thickening of a wall of the crimp terminal  232 , or at least one impression in a wall of the crimp terminal  232 , for example, a dimple  234  as described below. A corrugation  233  is shown in  FIGS. 6, 8, 9 and 16  and a dimple  234  is shown in  FIGS. 7, 10, 11 and 13-15 . 
     The cable contact section  193  of the respective contact element  190  can be configured such that the longitudinal end section  433  of the respective inner conductor  430  is well clamped. In an embodiment, the respective cable contact section  193  can have a rounded corner region as described in greater detail below with reference to  FIGS. 6-16 . 
     In an embodiment, it is possible to fix two crimp terminals  232 ,  232  to each other, which are opposite each other in a conductor crimping section  230 , by a wedge or a dovetail joint. This mechanical connection can also be set in place using a laser welding  235 . In another embodiment, instead of a wedge or a dovetail joint, a laser welding  235  can be applied to the two crimp terminals  232 ,  232 . 
     Additional embodiments will now be described with reference to one individual contact chamber  139  shown in  FIGS. 6-16 . As described above and shown in  FIGS. 6-16 , the contact carrier  11  has two side-by-side contact chambers  139  in an embodiment in which the cable  40  is a two-pole coaxial cable  40 ; the same description applies to each of the contact chambers  139 . 
     In the embodiment shown in  FIG. 6 , the top wall or wing  134 , a cable contact section  193  which is I-shaped in cross-section, and the longitudinal end section  433  of the respective inner conductor  430  are in the contact chamber  139  and crimped laterally onto the cable contact section  193  via a crimp terminal  232  by the wing  134 . The crimp terminals  232 ,  232 , which each have a corrugation  233 , are connected by a wedge. 
     In the embodiment of  FIG. 7 , the top wall or double wing  134 , a cable contact section  193  which is I-shaped in cross-section, and the longitudinal end section  433  of the respective inner conductor  430  are in the contact chamber  139  and crimped laterally onto the cable contact section  193  via a crimp terminal  232  by the double wing  134 . The crimp terminals  232 ,  232 , which each have dimples  234 , are mechanically connected by a laser welding  235 . 
     In the embodiment of  FIGS. 8 and 9 , the top wall or wing  134 , a cable contact section  193  which is L-shaped in cross-section, and the longitudinal end section  433  of the respective inner conductor  430  are in the contact chamber  139  and crimped onto an inner, rounded corner region of the cable contact section  193  via a crimp terminal  232  by the wing  134 . The crimp terminals  232 ,  232 , which each have a corrugation  233 , are mechanically connected by a wedge. 
     In the embodiment of  FIGS. 10 and 11 , the top wall or double wing  134 , a cable contact section  193  which is L-shaped in cross-section, and the longitudinal end section  433  of the respective inner conductor  430  are in the contact chamber  139  and crimped onto the inner, rounded corner region of the cable contact section  193  via a crimp terminal  232  by the double wing  134 . The crimp terminals  232 ,  232 , which each have dimples  234 , are mechanically connected by a laser welding  235 . 
     In the embodiment of  FIGS. 12-14 , the top wall or double wing  134 , a cable contact section  193  which is I-shaped in cross-section and substantially S-shaped in the longitudinal direction, and the longitudinal end section  433  of the respective inner conductor  430  are in the contact chamber  139 . The longitudinal end section  433  of the respective inner conductor  430  is positioned between two longitudinal sections of the cable contact section  193  which are arranged superimposed in a substantially parallel manner. The longitudinal end section  433  of the respective inner conductor  430  is clamped between the two longitudinal sections of the cable contact section  193  via a crimp terminal  232  by the double wing  134 . The crimp terminals  232 ,  232 , which each have dimples  234 , are mechanically connected by a laser welding  235 . Further, as shown in  FIG. 14 , the two circumferential edge sections of the crimp terminals  232 ,  232  are latched. In another variation shown in  FIG. 13 , it is possible to dispense with the laser welding  235 . 
     In the embodiment of  FIGS. 15 and 16 , the top wall or double wing  134 , a cable contact section  193  which is U-shaped in cross-section, and the longitudinal end section  433  of the respective inner conductor  430  are in the contact chamber  139 . A longitudinal end section of a first limb of the U-shaped cable contact section  193  is crimped by a wing of the double wing  134  onto the longitudinal end section  433  of the respective inner conductor  430 . The longitudinal end section  433  is further crimped to a longitudinal end section and a corner region of a second limb of the U-shaped cable contact section  193  opposite the first limb in the vertical direction H. 
     In the embodiment of  FIGS. 15 and 16 , a double wing  134 , a cable contact section  193  which is U-shaped in cross-section, and the longitudinal end section  433  of the respective inner conductor  430  are in the contact chamber  139 . A longitudinal end section of a first limb of the U-shaped cable contact section  193  is crimped by a wing of the double wing  134  onto the longitudinal end section  433  of the respective inner conductor  430 . The longitudinal end section  433  is further crimped to a longitudinal end section and a corner region of a second limb of the U-shaped cable contact section  193  opposite the first limb in the vertical direction H. 
     A substantially three-stage method of producing a two-pole coaxial cable  40  with a contact unit  10  will now be described in greater detail with reference to  FIGS. 4 and 5 . 
     In Step I, the coaxial cable  40  is prepared by mounting of a ferrule  400 . Step I includes up to four or more substeps and a prefabricated coaxial cable  40  is obtained at the end of Step I. 
     In Substep I.1, the coaxial cable  40  is stripped from an outer insulation  450  at its free longitudinal end section and thus a longitudinal end section  443  of the outer conductor  440  of the coaxial cable  40  is exposed as shown in  FIG. 1 . 
     In a Substep I.2, the ferrule  400  shown in  FIG. 1  is then fastened to a rear section of the longitudinal end section  443  of the exposed outer conductor  440 . The rear section of the longitudinal end section  443  of the exposed outer conductor  440  is inserted into the ferrule  400 , which is located on a carrier strip, and is then crimped thereon. Subsequently, the ferrule  400  is separated from the carrier strip. 
     In another embodiment, the ferrule  400  is first separated from the carrier strip, then the ferrule  200  is moved onto the rear section of the longitudinal end section  443  of the exposed outer conductor  440  and crimped thereon. The rear section of the longitudinal end section  443  of the exposed outer conductor  440  and the ferrule  400  may also be moved towards each other. 
     The ferrule  400  is plastically deformable and integrally formed. The ferrule  400  is open and has two crimping flanks prior to mounting on the coaxial cable  40 . Each crimping flank of the ferrule  400  has a circumferential edge section. The two circumferential edge sections are formed substantially complementary or substantially in a form-fitting manner with each other such that an enclosure is formed in a light-tight manner between the crimping flanks of the mounted ferrule  400  in the longitudinal direction L. 
     In a Substep I.3, a free section of the outer conductor  440  is disposed outside of the ferrule  400 . In an embodiment in which the Substep I.3 is omitted, it is obligatory to make the ferrule  400  from an electrically conductive material. In another embodiment, a free end of the outer conductor  440  substantially coincides with a free end of the ferrule  400  in the longitudinal direction L. 
     In a Substep I.4, a free longitudinal end section of an electrical inner insulation  410  of the coaxial cable  40 , which protrudes at the free end of the outer conductor  440 , is stripped. Subsequently, two free longitudinal end sections  433  of two inner conductors  430  protrude from the coaxial cable  40  as shown in  FIG. 1 . In this Substep I.4, the inner conductors  430  are freed from the inner insulation  410 , except for one comparatively short rear section. 
     In Step II, the free longitudinal end sections  433  of the two inner conductors  430  are positioned in the two contact chambers  139  of the conductor clamping section  130  of the contact carrier  11  and are linearly advanced therein. The contact carrier  11  is already disposed in the shield contact device  12 , which has not yet been crimped. In another embodiment, the inner conductors  430  are initially disposed in the two contact chambers  139  and subsequently provide the contact carrier  11  together with the coaxial cable  40  in the shield contact device  12  which has not yet been crimped. The crimp contact unit  10  including the contact carrier  11  and the contact shield device  12  is then ready to be crimped. 
     In Step III, a single crimp action is carried out which connects the coaxial cable  40  in an electrically conductive and mechanically fixed manner to the contact carrier  11  and also in an electrically conductive and mechanically fixed manner to the shield contact device  12 . Three crimps, including an inner conductor crimp, an outer conductor crimp and an insulation crimp, are established substantially simultaneously as described above. When carrying out the crimp method, the contact device  12  can still be located on a carrier strip  290  shown in  FIG. 1  or may already have been separated from the carrier strip  290 . 
     In other embodiments, the elements described above can be applied to all contact carriers, crimp contact units and production methods of cable assemblies. Embodiments including the features described herein can be applied anywhere that crimp connections are to be produced or established, including in applications beyond the automotive industry and beyond coaxial cables.