Patent Publication Number: US-8109787-B1

Title: Swivel connector

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not Applicable 
     STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT 
     Not Applicable 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates generally to components for interconnecting electrical devices, and more particularly, to a connector for a conductive cable that rotates or swivels about the terminal to which it is engaged. 
     2. Related Art 
     Electronic systems are typically comprised of several distinct sub-components or hardware device modules that are interconnected. Each of the sub-components serves a specific purpose, which together in combination provides the overall functionality of the system. There are numerous examples of such modular systems in a variety of fields. While higher-level functionalities may be incorporated into different components, a simple example is an external power supply. A battery or a generator may provide electrical power, but the form in which it is provided may not be suitable for a given electronic device. Thus, a power supply including a transformer and/or signal conditioning circuitry can be connected to the source. As one example application, a vehicle-mounted Global Positioning System (GPS) receiver may be powered by an external power supply that is connected to the primary battery of the vehicle. 
     A common connection modality between such modular components is an electrically conductive cable that has at least one line dedicated for signal transmission. One or both of the modular components may have a terminal. In some cases, the cable may be attached permanently to component, in which case a terminal would not be necessary therefor. The free end(s) of the cable have connectors that can be mated to the terminal. The connector (on the cable end) and the terminal (on the component end) are typically configured in pairs, in which a socket is fitted within a receptacle and electrical contacts of the two are connected to each other. The length of the interconnection between various components may also be increased by linking socket/receptacle pairs of multiple cables. Numerous connector standards define various dimensional features of the connectors and terminals to ensure physical interconnectivity. At a minimum, the connector standards define which contacts on the terminal correspond to the contacts of the connector, so that signals are consistently transmitted across the cable without one contact being cross-linked to a different contact. Thus, in the example of the power supply, the power line of the cable end is not shorted to ground, and so forth. In some instances, the standard may also define the contents of the signal traversing various lines within the cable. 
     For applications where the sub-components are frequently connected and disconnected, the durability of the connector between the cable and the terminal is a significant design objective. A related issue associated with the frequent movement or connection/disconnection of cables is its propensity to twist, tangle, and/or kink, leading to disorder at the very least, and possibly even damage to the cable, the connector, and the electrical components. With the vehicle-mounted GPS units mentioned in the example above, the power cable may be routed from a variety of different directions. Thus, various rotating or swiveling connectors have been developed, though weaknesses associated with the moving joints of such connectors persist. A further design parameter of connectors is the environment in which the electronic systems are deployed. In many cases, the systems are deployed under harsh conditions such as dusty/sandy environments, wet environments, and extreme cold or hot temperature environments. 
     Accordingly, there is a need in the art for an improved swivel connector that is resilient to withstand frequent engagement and disengagement from the terminal, as well as being substantially impervious to environmental conditions. 
     BRIEF SUMMARY 
     In accordance with one embodiment, there is disclosed a swivel connector for coupling a cable to a terminal. The swivel connector may include a socket contact plug in electrical communication with the terminal. Additionally, there may be a fixed joint bushing attachable to the terminal with the socket contact plug that extends therethrough. There may also be a joint housing that is rotatably engaged to the fixed joint bushing. The swivel connector may further include a primary terminal that is axially mounted to and electrically isolated from the joint housing. This primary terminal may include an inner sleeve contact that is frictionally engaged to the socket contact plug. Furthermore, there may be an outer sleeve contact that is fixed to the joint bushing. The outer sleeve contact may also be in electrical communication with the joint housing and with the terminal. The joint housing may be rotatably engaged to the outer sleeve contact. 
     Another embodiment of the present disclosure contemplates a swivel connector with various features. The swivel connector may couple a cable with a first line and a second line to a terminal with a corresponding first lead and a second lead. In various embodiments, the swivel connector may include a coupling nut with a hollow cylindrical portion. Additionally, there may be a socket body that is in a freely rotating coaxial engagement with the coupling nut. The socket body may extend through the hollow cylindrical portion. The swivel connector may further include a fixed joint bushing that is attached to the socket body and defines an axial interior first bushing contact slot. There may also be a joint body that is mounted to the fixed joint bushing and the socket body in a coaxial relationship thereto. Furthermore, there may be a joint housing that is rotatably engaged to the joint body. The swivel connector may include a first socket contact that is electrically connectible to the first lead of the terminal. The first socket contact may extend through the socket body and the first bushing contact slot. In a related feature, there may be a first connector terminal that is fixed to the joint housing in electrical isolation therefrom. The first connector terminal may be in a continuous frictional rotating engagement with the first socket contact, and may also be connectible to the first line of the cable. Another contemplated feature of the swivel connector is a second socket contact that is electrically connectible to the second lead of the terminal, and also extends through the socket body. There may also be a second connector contact that includes a sleeve portion fitted at least partially over the fixed joint bushing and between the joint body. The second connector contact may be in electrical communication with the second socket contact and electrically isolated from the first socket contact. Furthermore, the second connector contact may be connectible to the second line of the cable. The present invention will be best understood by reference to the following detailed description when read in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features and advantages of the various embodiments disclosed herein will be better understood with respect to the following description and drawings, in which: 
         FIG. 1  is an exterior side plan view of one embodiment of a swivel connector fixed to a conductive cable and a molded back shell, with select interior features being shown in broken lines; 
         FIG. 2  is a bottom plan view of the swivel connector as shown in  FIG. 1  along view A-A; 
         FIG. 3  is a perspective view of the swivel connector without the molded back shell; 
         FIG. 4  is a side view of the swivel connector with a retainer thereof being shown in broken lines; and 
         FIG. 5  is a cross-sectional view of the swivel connector taken along view B-B of  FIG. 4 . 
     
    
    
     Common reference numerals are used throughout the drawings and the detailed description to indicate the same elements. 
     DETAILED DESCRIPTION 
     Various embodiments of the present disclosure contemplate a swivel connector for coupling a cable to a terminal. In one particular application detailed more fully below, the connector is for a power supply cable to an electronic system deployed in harsh environmental conditions, such as a military vehicle-mounted Global Positioning System (GPS) receiver. Such cables are frequently connected and disconnected while being routed from a variety of different directions. The features of the swivel connector are suitable for such applications, though it is to be understood that it is not limited thereto. 
     The detailed description set forth below in connection with the appended drawings is intended as a description of the several presently contemplated embodiments of these connectors, and is not intended to represent the only form in which the disclosed invention may be developed or utilized. The description sets forth the functions and features in connection with the illustrated embodiments. However, that the same or equivalent functions may be accomplished by different embodiments that are also intended to be encompassed within the scope of the present disclosure. It is further understood that the use of relational terms such as first and second, top and bottom, distal and proximal, and the like are used solely to distinguish one from another entity without necessarily requiring or implying any actual such relationship or order between such entities. 
     With reference to  FIG. 1 , a swivel connector  10  attached to a cable  12  is shown in a state decoupled from a terminal  14 , though axially aligned with the same in such a manner to ready for coupling. The terminal  14  is understood to be fixed to an electronic component  16 . In continuing with the example above, the electronic component  16  may be a vehicle-mounted GPS receiver, though any other device may be substituted. The GPS receiver or the electronic component  16  may receive power over the cable  12 , with the end opposite to the swivel connector  10  being connected to an electrical power source (not shown). 
     Generally, the swivel connector  10  is configured for secure coupling to the terminal  14 . In further detail, there is a recess  18  defined by the electronic component  16 , within which certain portions of the swivel connector  10  are inserted. As mentioned previously, the terminal  14  is typically a receptacle, and mates with a corresponding socket on the swivel connector  10 . The recess  18  thus defines a part of the receptacle. Variously illustrated in  FIGS. 1-5 , the swivel connector  10  includes a coupling nut  20  defined by a knob section  22  and a socket section  24 . The knob section  22  is understood to be wider than the socket section  24  or any other part of the swivel connector  10 , as the end user grasps this portion to thread the swivel connector  10  on to the terminal  14 . In this regard, the outer surface of the knob section  22  can have a knurled surface for increasing grip traction. 
       FIG. 5  best illustrates the internal configuration of the coupling nut  20 , which includes a hollow cylindrical portion  26 . The inner circumference  28  of the cylindrical portion  26  is threaded, and is engageable to a correspondingly threaded receptacle post  30  disposed within the recess  18  as shown in  FIG. 1 . The receptacle post  30  is contemplated to have a generally cylindrical configuration, and also defines inner hollow cylindrical portion  32 . 
     In accordance with another aspect of the present disclosure, the swivel connector  10  includes a socket body  34  that is in a freely rotating coaxial engagement with the coupling nut  20 . More particularly, the socket body  34  extends through the aforementioned hollow cylindrical portion  26  of the coupling nut  20 . The socket body  34  is understood to be fitted inside the inner hollow cylindrical portion  32  of the receptacle post  30 . As shown in  FIG. 5 , the coupling nut  20  is defined by an inner lip portion  36  that is in abutting contact with a corresponding radially protruding portion  38  of the socket body  34 . In this regard, the socket body  34  is understood to be retained within the hollow cylindrical portion  26  and prevented from further upward movement against the coupling nut  20 . Along these lines, the downward movement against the coupling nut  20  is also prevented, the details of which will be considered more fully below. 
     Within the inner hollow cylindrical portion  32  of the receptacle post  30 , there are a first lead  40  and a second lead  42 . These leads are understood to be electrical contacts and so are constructed of a suitably electrically conductive material such as gold plated bronze and so forth. In the contemplated exemplary configuration, the first lead  40  is associated with a power transmission path, while the second lead  42  is associated with common path. Referring to  FIG. 2 , disposed within the socket body  34  is a first socket contact  44  that is connected to a first line in the cable  12 , and the a second socket contact  46  that is connected to a second line in the cable  12 . In likewise fashion, the first socket contact  44  is associated with a power transmission path, and the second socket contact  46  is associated with a common path. Again, considering that the first socket contact  44  and the second socket contact  46  are utilized to make electrical connections, these components are likewise understood to be constructed of an electrically conductive material. To isolate one contact from the other, however, the socket body  34  is constructed of an electrically insulating material such as a composite of nylon and fiber. Although in  FIG. 2  there is illustrated a third socket contact  48 , for purposes of the presently disclosed embodiment of the swivel connector  10 , this is not tied to a corresponding line in the cable  12 . 
     The first socket contact  44  and the second socket contact  46  are disposed within a first socket contact slot  50  and a second socket contact slot  52 , respectively, and are defined by the socket body  34 . The first socket contact  44  and the second socket contact  46  are electrically conductive and flexible with slightly undersized dimensions relative to the dimensions of the first lead  40  and the second lead  42  of the terminal  14 . When the first lead  40  and the second lead  42  are inserted into the first socket contact slot  50  and the second socket contact slot  52 , respectively, it is understood that the first socket contact  44  and the second socket contact  46  expand slightly to frictionally engage the first lead  40  and the second lead  42 . In this way, electrical contact between the first lead  40  and the first socket contact  44  is maintained, as is the electrical contact between the second lead  42  and the second socket contact  46 . 
     When the swivel connector  10  is coupled to the terminal  14 , the coupling nut  20  is threaded on to the receptacle post  30  and received within the recess  18 . Furthermore, the position of the socket body  34  is fixed in relation to the receptacle post  30 , and hence the terminal  14 . As noted above, the coupling nut  20  includes an inner lip portion  36  that engages to the protruding portion  38  of the socket body  34 . As the coupling nut  20  is threaded on to the receptacle post  30 , the inner lip portion  36  exerts a downward retention force upon the protruding portion  38  of the socket body  34 , thereby temporarily fixing the swivel connector  10  to the terminal  14 . Since the socket body  34  is then disposed within the receptacle post  30  on the terminal  14 , and the first lead  40  and the second lead  42  are inserted into the first socket contact slot  50  and the second socket contact slot  52 , rotational movement of the socket body  34  is restricted. Although particular features of the swivel connector  10  as pertaining to the coupling nut  20  and the socket body  34  have been described, it will be appreciated that there are alternative configurations therefor. The dimensions and profiles of the socket body  34  and the coupling nut  20  in the illustrated embodiment are understood to comply with the Picofast®/MFS series connector produced by Hans Turck GmbH &amp; Co, KG of Germany, though any other connector standard may be substituted. 
     Referring now to  FIG. 5 , the features of the swivel connector  10  that enable the attached cable  12  to rotate about axis  1 - 1  relative to the terminal  14  will be described. The socket body  34  extends through a central opening  54  defined by the coupling nut  20 . The socket body  34  is attached to a fixed joint bushing  56 , which like the socket body  34 , is constructed of an electrically insulating material. The fixed joint bushing  56  has a generally cylindrical configuration coaxial with the axis  1 - 1 . Furthermore, the fixed joint bushing  56  defines an axial interior first bushing contact slot  58 , through which the first socket contact  44  is routed. The axis of the first bushing contact slot  58  is centered on and aligned with the axis  1 - 1 . The first socket contact slot  50  has an axis that, while extending in a parallel relationship to the axis  1 - 1 , is offset therefrom. In other words, the first socket contact slot  50  is not centered within the socket body  34 . Accordingly, the first socket contact  44  is routed in an angular relationship between the first socket contact slot  50  and the first bushing contact slot  58 ; the first socket contact  44  thus has an angled section  59 . In some contemplated embodiments, the angled section  59  may be a separate and independent component from the first socket contact  44  that is mechanically attached to establish an electrical connection. Along these lines, while the first socket contact  44  (and the second socket contact  46 ) has been previously referenced as a single contiguous part aside from the foregoing angled section  59 , this is not necessary feature and the socket contacts may be divided into one or more other separate parts. Reference to a single socket contact is for purposes of simplification only. Any other suitable configuration may be employed for routing a conductive path from the socket body  34  to the center of the fixed joint bushing  56 . 
     The socket body  34  and the fixed joint bushing  56  remain stationary relative to the terminal  14  when coupled thereto, so the first socket contact  44  likewise remains stationary. The swivel connector  10  further includes a first connector terminal  60  that is in continuous frictional rotating engagement with the first socket contact  44 . In further detail, the first connector terminal  60  includes a sleeve portion  61  that is fitted over a plug portion  63  of the first socket contact  44 . The sleeve portion  61  freely rotates around the plug portion  63  while remaining in electrical contact therewith. The sleeve portion  61  may be have slightly undersized dimensions relative to the plug portion  63 , and being constructed of a flexible, electrically conductive material (metal), the sleeve portion  61  compresses against the plug portion  63 . Although the sleeve portion  61  need not completely enclose the plug portion  63 , it is understood that at any given rotation point, electrical contact between the two is maintained. 
     The first connector terminal  60  is attached to a joint housing  62 , and more specifically, to a joint insulator  64  that is fixed to the joint housing  62 . The joint insulator  64  is defined by a flanged portion  66  and a journal portion  68 , with the first connector terminal  60  extending through a central axis thereof. The flanged portion  66  is mounted to the joint housing  62 , and the journal portion  68  is rotatably engaged to a corresponding cylindrical bearing portion  70  defined by the fixed joint bushing  56 . That is, the journal portion  68  of the joint insulator  64  is received in the cylindrical bearing portion  70  of the fixed joint bushing  56 , and is rotatable about the axis  1 - 1 . As indicated above, the first connector terminal  60  rotates, and the joint insulator  64  and the joint housing  62  to which it is attached, rotates as well. While the first connector terminal  60  is mechanically attached to the joint housing  62 , it is electrically isolated therefrom. In this regard, the joint insulator  64  may be constructed of a non-conductive material such as polytetrafluouroethylene (PTFE). 
     The joint housing  62  is also rotatably engaged to a joint body  72 , which is mounted to the fixed joint bushing  56  and the socket body  34  in a coaxial relationship thereto. Similar to the first socket contact slot  50  discussed above, the second socket contact slot  52  is parallel with the central axis  1 - 1  but offset therefrom. The second socket contact  46  is routed through the second socket contact slot  52 , and is routed externally from the socket body  34  to electrically connect the same to a second connector contact  74 . The second socket contact  46  is thus understood to include an angled section  76  for this purpose. 
     In further detail, the second connector contact  74  includes a sleeve portion  78  that is fitted at least partially over the fixed joint bushing  56 . The sleeve portion  78  is thus sandwiched between the joint body  72  and the fixed joint bushing  56 . The second connector contact  74  is fixed to the joint body  72  and the fixed joint bushing  56  in a non-rotating relationship, but the joint housing  62  is understood to rotate around the sleeve portion  78  as well as the joint body  72 , as mentioned above. The second connector contact  74  is also routed to an external portion of the joint body  72  for electrically connecting to the second socket contact  46 . 
     The joint body  72  is constructed of an electrically conductive material, which according to one embodiment is brass that may be coated with a layer of nickel. Thus, the joint body  72  is also electrically connected to the second connector contact  74 . Indeed, this connection is maintained across the entire rotational range of the joint housing  62  relative to the joint body  72 . Again, like the sleeve portion  61  of the first connector terminal  60 , the sleeve portion  78  of the second connector contact  74  need not be completely encompassed by the joint housing  62 , just that the electrical connection between these components is consistently maintained. It is noted that although there is a mechanical connection between the joint body  72 , the second connector contact  74 , and the fixed joint bushing  56 , the first socket contact  44  is isolated therefrom, as the fixed joint bushing  56  is constructed of a non-conducting material. According to the one exemplary configuration discussed above, the second connector contact  74 , as well as the other components noted herein as being electrically connected thereto including the joint body  72 , the joint housing  62 , and the second socket contact  46 , are associated with a common signal path for the power supply. 
     With reference again to  FIG. 1 , the first connector terminal  60  is connected to a first line  80  that is associated with a signal or power transmission path, while the joint housing  62  is connected to a second line  82  that is associated with a common signal path. In some embodiments, the common signal is carried over a conductive sheath surrounding a non-conductive sheath, and has been depicted thus in  FIG. 1 . As shown in  FIG. 3  and  FIG. 4 , the joint housing  62  includes a wire anchoring recess  84 , to which an extension from the conductive sheath of the second line  82  can be attached. 
     As noted above, protection from harsh external environments is one pertinent consideration for the swivel connector  10 . One of the contemplated features, then, is a backshell  86  that substantially encloses the joint housing  62  and several other components of the swivel connector  10 . It is understood that the backshell  86  is rigidly molded on to the joint housing  62  and related components. The cable  12  is attached to the backshell  86 , and the junction between the two components includes relief collars  88  for strengthening the joint and limiting flex. For ease in manipulation, the backshell  86  may have a grip depression  90 . 
     For further enclosing the otherwise exposed portions of the socket body  34 , the joint body  72 , and the second socket contact  46  is a retainer member  92 . In particular, the retainer member  92  is fitted over and fixed to the socket body  34 , and is axially interposed between the coupling nut  20  and the joint housing  62 . It was previously noted that the upward, axial movement of the socket body  34  is limited by the inner lip portion  36  of the coupling nut  20 . The downward, axial movement of the socket body  34 , in turn, is understood to be limited by the retainer member  92 . Being fixed to the socket body  34  and the joint body  72 , the joint housing  62  and the backshell  86  rotate relative to the retainer member  92 . 
     Partly in order to prevent environmental intrusion of the sleeve portion  78  of the second connector contact  74  and the first connector terminal  60 , the joint body  72  defines a circumferential groove  94 , within which a sealing member  96  is disposed. According to one contemplated embodiment, the sealing member  96  is an O-ring. As a further sealing measure, in addition to lubrication for smooth swiveling of the joint housing  62 , the interface between the joint body  72  and the joint housing  62  includes a film of silicon grease, though any other suitable material may be substituted. 
     The particulars shown herein are by way of example and for purposes of illustrative discussion of the embodiments of the present disclosure only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects. In this regard, no attempt is made to show details of the present invention with more particularity than is necessary, the description taken with the drawings making apparent to those skilled in the art how the several forms of the present invention may be embodied in practice.