Patent Publication Number: US-2016240957-A1

Title: Sealed electrical cable connector

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit under 35 U.S.C. §119(a) of Patent Application No. 15154927.6 filed in the European Patent Office (EPO) on Feb. 12, 2015, the entire disclosure of which is hereby incorporated by reference. 
    
    
     TECHNICAL FIELD OF THE INVENTION 
     The invention relates to a sealed electrical cable connector for vehicles, in particular for use with in-vehicle networks, and a method for manufacturing a network cable with such a connector. 
     BACKGROUND OF THE INVENTION 
     In automotive engineering, networks have become essential that interconnect intelligent nodes. With the use of networks and intelligent nodes, it has become possible to economize on signal lines in vehicles. At the same time, there is an increase in safety and comfort. However, in networks for data transmission, the technical characteristics need to be considered in comparison to conventional wiring of vehicles. This means that lines need to be used configured to the signals to be transmitted. Thereto, coaxial cables, fiber optics, or so-called twisted pair cables are used, known from computer systems. Twisted pair cables are cables having twisted pairs of conductors that are shielded or unshielded. The conductor pairs usually have a second common isolation layer giving the cable more mechanical stability. In practice, twisted pair cables have proved to be particularly practical. The number of nodes in modern vehicles is continuously increasing with the development of new features. Since space in vehicles is limited and weight also is of importance, miniaturized connector systems are used. Miniaturized connector systems are relatively difficult to process in manufacturing of vehicles. A certain degree of robustness is required during assembly. At the same time, there is an increase in data rates that need to be transmitted over the networks. This results in additional challenges that must be mastered. The nodes, connectors and cables need to be configured to each other to avoid errors in signaling. Thereto, it is necessary to provide the conductors of the twisted pair cables as close together as possible, from the source to the target. A known solution is to construct the connectors in a modular way and to provide the cables for the networks as separate conductor sets. As a result, the handling can be facilitated in manufacturing the cable set, since the network connection cables can be pre-assembled separately. The network connection cables are supplied complete with connectors at their ends and integrated into connector housings of the cable set. 
     In vehicles, sets of cables need to be sealed against moisture and debris. Examples are seen in EP1024557 and WO2013031088. However, in this case, the modularization has a negative effect. The effort necessary for sealing increases. The sealing of modular connector systems, notably with high-speed network connections, presents the developers with major problems. 
     The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also be inventions. 
     BRIEF SUMMARY OF THE INVENTION 
     An electrical connector is presented herein. The electrical connector comprising a first connector housing having a first side configured for connection to a complementary connector, and a second side with at least one opening expanding in the insertion direction to a cavity. At least a second connector housing which can be held in the at least one cavity of the first connector housing. A seal that is attachable to the second side of the first connector housing, a seal holder that holds the seal at the second side of the first connector housing, wherein the seal comprises at least one opening aligned with the opening of the first connector housing in insertion direction. Wherein the opening in the seal is smaller than the opening in the first connector housing. 
     A method for manufacturing a connection line for a network is presented herein. The method comprises the steps of:
         a) providing a first connector housing;   b) attaching a seal to the second side of the first connector housing;   c) providing a second connector housing with an electrically connected and mechanically attached network cable;   d) inserting the second connector housing through an opening in the seal into an opening of the first connector housing;   e) moving the second connector housing until the second connector housing is received and held in the cavity of the first housing;   f) attaching a seal holder to the second side of the first connector housing so that the seal is held on the first connector housing.       

     According to an embodiment, the second connector housing comprises a front face and side faces. The side faces extend from the front face contrary to the insertion direction, wherein the transition areas between the surfaces are rounded and/or chamfered. Upon insertion of an object with sharp corners into an opening of a resilient material, the material can readily tear. By rounding or chamfering the transition areas between the front and side faces, the sliding of the second connector through the opening of the seal is made possible without damaging the seal by sharp edges and corners. The rounded or chamfered side edges (transition areas parallel to insertion direction) prevent damage to the opening of the seal when inserting the second connector housing. When using a connector housing having a circular cross-section that requirement is dispensable. In the present embodiment, however, the orientation of the second connector housing in the first connector housing is important. 
     According to another embodiment, the front edges and the side edges (transition areas), sliding along the seal during insertion of the second connector housing through the opening of the seal, are rounded and/or chamfered. By removing sharp edges by means of chamfering or rounding, the risk of damage to the opening of the resilient seal is minimized when inserting the second connector housing. However, it is sufficient to de-sharpen only the areas of the second connector housing which come into contact with the seal when sliding through. 
     The seal may be integrally formed of a resilient material. With the use of an integrally formed seal, the manufacturing costs are reduced. In comparison to individual conductor sealing, the integrally formed seal is cheaper to produce and more cost-effective in assembly. Also, seal in layers may be used with which different passage geometries can be realized. The smaller second connector housings may be inserted through the resilient openings. 
     According to a yet another embodiment, the seal comprises recesses at its first side that faces the second side of the first connector and/or at its second side that faces the seal holder. The seal, which in this embodiment is made of silicone, has recesses at its first side. Depending on the design of the first housing, projections of the first connector housing may protrude into the recesses. These projections maintain the seal in the desired position. Thus, it is ensured that the openings of the seal are aligned with the openings of the first connector housing. However, the recesses may not be occupied by housing parts. The flexibility of the seal is improved when the silicone has space for expansion. The recesses at the second side of the seal also provide space for expansion of the material of the seal when a second connector housing is inserted through the opening. Since silicone is non-compressible, a possibility is provided to expand the openings without forcing the material toward the opening of the first connector housing. 
     According to an additional embodiment, the at least one opening in the seal is formed such that it sealingly surrounds a network cable. The size of the openings in the seal is determined according to the geometry of the second connector housing and the diameter of the network cable. The opening in the seal is dimensioned such that the second housing can slide through the opening without damage to the seal. Thereafter, the seal tightly surrounds the network cable. 
     The seal may comprise silicone or consist of silicone. The use of silicone has the advantage, among others, that during manufacture of silicone seal most often some oil remains on the seal, which facilitates the insertion of the second connector housings. With appropriately configured design, a silicone seal could be molded to the first housing. However, this embodiment is not further pursued here. 
     According to another embodiment, the seal holder is formed of several parts. The electrical connector is mounted in an order in which the seal holder is attached to the second side of the first connector housing in the last step of the procedure. At this point, several network cables project from the second side of the first connector housing, in particular with connectors receiving more than one second connector housing. Since the seal holder has a plurality of parts, the seal holder may be positioned around the network cables and the seal, even between the network cables, may be held at the second side of the first connector housing. 
     The parts of the seal holder may be movably connected with each other. The parts of the seal holder are connected with each other to improve the handling during assembly. The parts need not be collected to fit and cannot be easily lost. They may be connected to each other by means of film hinges, for example. The use is predefined by the position of the connection. The parts can be assembled only in a certain way, so that errors during assembly can be virtually ruled out. 
     One or more parts of the seal holder may have a recess perpendicular to the insertion direction. The seal holder may be arranged between network cables such that a network cable is received in the recesses. Another part of the seal holder is connected to the first part such that the network cable is completely surrounded by the seal holder. In particular with connectors with a plurality of second connector housings, this seal holder may be easily arranged and assembled between the network cables. The network cables do not need to be threaded through openings, which greatly facilitates the assembly. After the individual parts are connected to each other, they form a stable lid. 
     The seal holder may comprise projections in the insertion direction and/or contrary to the insertion direction. The projections of the seal holder, which project in insertion direction, are inserted into the recesses of the seal in the last step of the assembly of the seal holder. The projections occupy the space that the seal requires during insertion of the second connector housing to expand the opening. Thus, the opening of the seal cannot expand and peripherally abuts to the isolation of the twisted pair cable. This improves the sealing. The projections of the seal holder, which project from the second side of the first connector housing contrary to the insertion direction, have a mechanical stabilizing effect for the seal holder. The arrangement of the projections may be selected such that a water reservoir is formed when a jet of water splashes onto the seal holder. The water between the projections reduces the water pressure in the area between the seal and the isolation of the network cable. 
     In manufacture of the connection line, the second connector housing may be completely inserted through the opening in the seal. This facilitates the handling during assembly. These are very small connector systems which are difficult to handle in conventional manner. 
     According to another embodiment, the seal holder is first placed between the network cables and then the remaining parts are placed around the network cables. This creates a closed surface through which the network cables protrude. From the individual parts, a massive plate is formed that holds the seal at the housing and additionally seals the network cables. 
     According to yet another embodiment, the seal holder is arranged such that the projections of the seal holder protrude into the recesses of the seal. The projections displace the seal from the recesses and press the seal against the network cables. Thus, the sealing is improved and the seal is maintained in position. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
       The present invention will now be described, by way of example with reference to the accompanying drawings, in which: 
         FIG. 1  shows a modular connector according to the prior art; 
         FIGS. 2 a  -2 c    show three views of the first housing of the connector; 
         FIGS. 3 a  -3 c    show three views of the second housing of the connector; 
         FIGS. 4 a  -4 c    show three views of the seal of the connector; 
         FIGS. 5 a  -5 c    show three views of the seal holder of the connector; 
         FIG. 6  shows a perspective view of the seal holder in the assembled state; 
         FIG. 7  shows an exploded view of the connector; 
         FIG. 8  shows a perspective view of the connector with open seal holder; 
         FIG. 9  shows a perspective view of the connector with closed seal holder; 
         FIG. 10  shows a perspective view of the connector with a seal holder attached to the first connector housing; and 
         FIG. 11  shows a cross-sectional view of the connector in the fully assembled state. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a modular connector  10 P according to the prior art. The connector has a first connector housing with chambers for receiving of contact portions attached to electrical lines. Also, the first connector housing has an opening  23 P for receiving a second connector  30 P to which a twisted pair cable  101 P is mounted. This connector concept uses single conductor seals as a seal for the second connector  30 P. However, the entire connector  10 P is not sealed. 
       FIG. 2 a    shows a perspective view of a first connector housing  20  and a connector  10 . The first connector housing  20  has a first side  21  which is configured to be connected with a complementary connector (not shown). The connector  10  is moved in insertion direction (x) to be connected to the complementary connector. The first connector housing  20  includes a second side  22 . The second side  22  comprises openings  23 . The openings  23  are configured for receiving further connector housings  30 . Cavities  24  are provided between the first side  21  and the second side  22 , in which the second connector housings  30  can be held. A collar  27  projects from the second side  22  contrary to the insertion direction x. The collar  27  surrounds the area in which the openings  23  are located. The surface of the second side  22  and the circumferential collar  27  form a receptacle for the seal  40 . Lugs  25  project from the first connector housing  20  contrary to the insertion direction (x). They serve for fastening of the seal holder  50 .  FIG. 2 b    shows a view of the second side  22  of the first connector housing  20 . A cross-sectional axis (A) extends perpendicularly through the first connector housing  20 .  FIG. 2 c    shows a sectional view of the first connector housing  20  along the cross-sectional axis (A). 
       FIG. 3 a    shows a perspective view of the second connector housing  30  of the connector  10 . The second connector housing  30  is configured such that it can be inserted into the cavity  24  of the first connector housing  20  and is held there. To be held in the cavity  24 , a detent mechanism  35  is provided at both housings  20 ,  30 . The second connector housing  30  is configured as a two-pole housing and has a substantially cuboid shape. The front part of the second connector housing  30 , relative to the insertion direction (x), comprises chamfered transition areas  33  between the surfaces  31 ,  32 . Thus, the circumferential transition area  33  surrounding the front surface  31  is de-sharpened. The angle between the front surface  31  and the side surfaces  32  of the second connector housing  30 , which is opposite to the insertion direction x, is flattened by being spread to two edges. The circumferential transition area  33  could also be rounded. The transition areas  34  of the cuboid second connector housing  30  along the insertion axis (x) are also chamfered or rounded.  FIG. 3 b    shows a side view of the second connector housing  30 . The second connector housing  30  is shown here as a two-piece component, though it is immaterial. Furthermore, the second connector housing  30  comprises a chamfered transition area  36 . The chamfered transition area  36  supports the sliding of the second connector housing  30  through the seal  40 . 
       FIG. 3 c    shows a sectional view of the second connector housing  30  wherein the section is in insertion direction. Inside the second connector housing  30 , a contact element  37  is shown having attached thereto a twisted pair cable  101 . The twisted pair cable  101  has a further isolation layer as is common with network cables  100 . 
       FIG. 4 a    shows a perspective view of the seal  40  of the connector  10 . The seal  40  here is shown as an integrally-formed flat block sealing. Sealing lips  46 ,  47  are formed on the outer periphery and within the openings. The sealing lips  47  on the outer periphery cooperate with the inner surface of the collar  27  to seal the second side  22  of the first connector housing  20 . The sealing lips  46  within the openings  43  are formed such that they cling to the network cables  100 . At the first side  41  and the second side  42  of the seal  40 , recesses  44 ,  45  are formed. The recesses  44 ,  45  serve as reservoir for the seal material during assembly of the connector  10 . At the point at which one of the second connector housings  30  is inserted through the opening  43 , the displaced seal material can flow into the recesses  44 ,  45  and the opening  43  may be easier to expand. A recess  48  at the upper edge of the opening  43  serves for alignment of the second connector housing  30  when being inserted through the seal  40 .  FIG. 4 b    shows a view of the second side  42  of the seal  40 . The sectional axis (A) shows the sectional cut through the seal  40 .  FIG. 4 c    shows a sectional view of the seal  40 . 
       FIG. 5 a    shows a perspective view of the seal holder  50  of the connector  10 . The seal holder  50  is formed in several parts. The individual parts  60 ,  61 ,  62  of the seal holder  50  here are held together by film hinges  56 . The arrangement of the film hinges  56  results in a predetermined sequence of movements to assemble the seal holder  50 .  FIG. 5 b    shows the first side  51  of the seal holder  50 . The seal holder  50  has projections  53 ,  54  on its first side  51  and second side  52 . The projections  53  protruding from the first side  51  protrude into the recess  44 ,  45  of the seal  40  when in the assembled state. The seal holder  50  comprises recess  70  through which the network cable  100  may be passed through the seal holder  50 . A detent mechanism  63 ,  64  is provided to hold together the parts  60 ,  61 ,  62  of the seal holder  50  after assembly. The detent mechanism  63 ,  64  includes a detent  63  and a closing tab  64  with which the detent  63  can engage.  FIG. 5 c    shows the second side  52  of the seal holder  50 . The second side  52  comprises projections  54  extending contrary to the insertion direction (x). 
       FIG. 6  shows the seal holder  50  in the assembled state. The detent mechanism  63 ,  64  and the hinges  56  hold together the parts  60 ,  61 ,  62  such that a lid-shaped structure is formed. The seal holder  50  comprises, at its edge, a circumferential collar  57  extending in the insertion direction x. Detents  58  are arranged on the outer side of the collar  57  with which the seal holder  50  can be fastened to the lugs  25  of the first connector housing  20 . 
       FIG. 7  shows an exploded view of the connector  10 . This view illustrates the method for mounting the connector  10 . The seal  40  is attached to the first connector housing  20 . Then, the second connector housings  30  with attached network cables  100  are inserted through the seal  40  into the first connector housing  20 . Thereafter, the seal holder  50  is arranged between the network cables  100 , assembled into a lid-like structure and connected to the first connector housing  20 . 
       FIG. 8  shows an exploded view of the connector  10 . The figure shows the connector  10  with the seal holder  50  arranged between the network cables  100 . The seal holder  50  is not yet folded into its lid-like shape. 
       FIG. 9  shows an exploded view of the connector  10 . The figure shows the connector  10  with the seal holder  50  arranged between the network cables  100 . The seal holder  50  is folded into its lid-like shape. In the next assembly step, the seal holder  50  is moved in insertion direction x until the collar  57  of the seal holder  50  is pulled over the collar  27  of the first connector housing  20  and the detent  58  of the seal holder  50  is locked into the lug  25  of the first connector housing  20 . 
       FIG. 10  shows a perspective view of the connector  10  in the assembled state. The network cables  100  protrude from the openings  23  of the first connector housing  20 , through the opening  43  of the seal  40 . The seal holder  50  is arranged between the network cables  100  and connected to the second side  22  of the first connector housing  20 . The connection is made by means of a snap mechanism  25 ,  58 . 
       FIG. 11  shows a sectional view of the connector  10  in the assembled state. The second connector housing  30  is received and held in the cavity  24  of the first connector housing  20 . The contact elements  37  in the second connector housing  30  are aligned in the insertion direction x and the conductors of the twisted pair cable  101  of the network cable  100  are connected to the contact elements  37 . The seal  40  is in contact with the second side  22  of the first connector housing  20 . The network cable  100  protrudes through the opening  43  of the seal  40 . The seal holder  50  is connected to the first connector housing  20  by a snap mechanism  25 ,  58 . The projections  53  of the seal holder  50  protrude into the recesses  45  of the seal  40  and hold the sealing lips  46  on the outer side of the network cable  100 . 
     While this invention has been described in terms of the preferred embodiments thereof, it is not intended to be so limited, but rather only to the extent set forth in the claims that follow. Moreover, the use of the terms first, second, etc. does not denote any order of importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items.