Abstract:
The disclosure relates to a cable grasping assembly and an associated waterproof lockable disengaging swiveling electrical cable connector housing structure. The assembly includes and end cap, a cable-holding sleeve and a housing. The end cap threads onto the housing in such a way that it causes fingers of the housing to compress the cable holding sleeve onto a cable which passes through the bores of all three. The structure includes a male housing partially inserted into the bore of a female housing. Each housing has a generally cylindrical body with a cable support structure located within its bore. The two housings are free to rotate about the cylindrical surfaces of each other when locked together via a locking sleeve. The structure also includes a sealing structure carried by one of the housings that establishes a watertight seal between the housings when the male is partially inserted into the female.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
       [0001]    This application is a Non-Provisional application claiming priority to the U.S. Provisional Application No. 61/788,162, filed Mar. 15, 2013, entitled “SWIVEL CONNECTOR”, of which is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    There are robotic cleaning vehicles for liquid filled containers that are connected to an electrical power source by a cable. These vehicles often follow tortuous paths of travel in accomplishing their cleaning missions and this results in torsional stress building up in the cables as they twist to accommodate the motion of the vehicles. This torsional stress can be somewhat relieved if segments of the cables rotate with respect to other segments of the same cables. This can be facilitated by inserting swivel joints into the cables. However, such joints need to ensure good electrical contact between the cable segments, isolate the electrical contacts from the liquid in which the vehicles are immersed when in operation and prevent the separation of the cable segments from each other when an axial force is applied to the cable segments. It would also be helpful if the segments of a cable could be readily disconnected from each other at a location between the power source and the vehicle when the vehicle is not in operation. One approach is to effect the electrical connection between the cable segments using a classical stereo jack and socket that has been modified by the placement of an O-ring to isolate the electrical contacts from the immersion liquid. For instance, the socket and the jack can be extended to provide for a groove to accommodate an O-ring in one of them that is distal from the tip of the jack when it is inserted in the socket. Such an arrangement is inadequate to resist the axial forces typically experienced by the cable segments when there is not some other structure to isolate the joint from these axial forces. One such structure is a rigid right angle elbow that encompasses a cable segment but it does not always operate to allow relief of the torsional stress from the movement of the vehicle as efficiently as is desired. 
       SUMMARY 
       [0003]    One embodiment involves a cable grasping assembly having an end cap with a bore with a decreasing diameter from one end to the other, a cable holding sleeve constructed of a readily compressible material and a housing with an interior bore for accommodating a cable. The end cap has a screw thread on the interior surface of its bore and a ledge that projects inward from the interior surface of the bore adjacent to the end with the smallest diameter. The cable holding sleeve has a generally circular bore which extends over its axial length, a series of ridges which extend radially from its outer surface and which extend axially over a significant portion of its axial length and a collar at one end beyond the axial terminus of the ridges which extends radially from the outer surface of the sleeve. The housing has a series of fingers which extend from one end of the housing with gaps between them to accommodate the ridges of the cable holding sleeve and which have an axial length such that their free ends terminate at the collar of cable holding sleeve and a screw thread on the exterior surface of the housing and spaced from the free end of the fingers. 
         [0004]    Another embodiment also involves a waterproof lockable disengaging swiveling electrical cable connector housing structure having a first housing having a cable support structure located within its bore for receiving a first electrical cable segment, a second housing having a cable support structure located within its bore for receiving having a second electrical cable segment and a locking sleeve operatively slidingly secured to the second housing and movable from a first position to a second position to lock the first housing to the second housing, such that the first housing is rotatable relative to the second housing when the locking sleeve is in the locked position. 
         [0005]    In other embodiments the structure includes a male housing partially inserted into the bore of a female housing. Each housing has a generally cylindrical body with a cable support structure located within its bore. It also has an interior cylindrical recess to accommodate a cable grasping sleeve, with this recess being located adjacent to the end of the housing distal from the end involved in the partial insertion. Each housing has additionally has an engagement structure for engaging a reciprocal engagement structure on the other housing in such a way that the two housings are free to rotate about the cylindrical surfaces of each other when locked together via their engagement structures and a locking sleeve. It further has a mechanism for affixing an end cap over the exterior surface of the housing which is located adjacent to the end of the housing carrying the recess for a cable sealing sleeve. The structure also includes a sealing structure carried by one of the housings which establishes a water tight seal between the housings when the male is partially inserted into the female and a cable grasping sleeves seated in their recess the housings and constructed of a compressible material. The structure further includes two end caps, each with a mechanism which interacts with the mechanism on one of the housings to affix the end cap to the housing in such a way that the interior diameter of the cable grasping sleeve seated in the housing is decreased and each end cap having an aperture which aligns with the cable support structure located within the bore of its housing. The structure additionally includes a locking sleeve which is manually moveable into and out of interaction with the engagement structures of the two housings such that as a result of the interaction they are locked into engagement and in this locked configuration do not allow axial movement between the two housings. 
         [0006]    A further aspect of the embodiments also involves a method of connecting an electrical power cable to a robotic cleaning vehicle for a liquid filled container by providing one electrical cable segment attached to the vehicle and another attached to a power source, equipping the free end of one cable with a classic stereo jack and the free end of the other cable with a classic stereo socket and inserting these free ends into the axially opposed ends of a waterproof lockable disengaging swiveling electrical cable connector housing structure described above such that the jack becomes will become seated in the socket to create two circuit paths when the housing is assembled. The method further involves affixing the end caps of the housing structure on their respective housings such that that housing&#39;s cable grasping sleeve grasps the cable segment inserted through its end cap, inserting the male housing into the female housing such that the jack affixed to one cable segment becomes will become seated in the socket affixed to the other cable segment to create two circuit paths and moving the locking sleeve to interact with the engagement structures of the two housings such that the two cable segments are securely held together against any axial force but are free to rotate with respect to each other. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is an isometric schematic illustration of a liquid containing vessel with a robotic cleaning vessel on its floor connected to an electrical power source via a cable with a swivel connector. 
           [0008]      FIG. 2  is a cross section of a locked assembled cable connector housing structure. 
           [0009]      FIG. 3  is a cross section of a disassembled cable connector housing structure. 
           [0010]      FIG. 4  is a cross section of an unlocked assembled cable connector housing structure. 
           [0011]      FIG. 5  is an isometric view of grasping fingers on an exterior end of a housing that is a part of a cable connector housing structure. 
           [0012]      FIG. 6  is an isometric view of grasping fingers on an exterior end of a housing that is a part of a cable connector housing structure and a cable grasping sleeve mounted on a cable segment. 
           [0013]      FIG. 7  is an isometric view of the cable grasping sleeve. 
           [0014]      FIG. 8  is a cross section of the exterior end of a housing that is a part of a cable connector housing structure and an end cap adapted to be threaded on this end. 
           [0015]      FIG. 9  is a cross section of the exterior end of a housing that is a part of a cable connector housing structure with the end cap threaded onto it. 
           [0016]      FIG. 10  is a cross section of  FIG. 9  along section line  10 - 10 . 
           [0017]      FIG. 11  is an isometric view of the exterior end of a housing that is a part of a cable connector housing structure and an end cap adapted to be threaded on this end. 
           [0018]      FIG. 12  is an isometric view of an alternative cable grasping sleeve. 
           [0019]      FIG. 13  is a cross section of an alternative exterior end of a housing that is a part of a cable connector housing structure and the alternative cable grasping sleeve. 
           [0020]      FIG. 14  is an exploded view along line  14 - 14  of a finger shown in  FIG. 13 . 
           [0021]      FIG. 15  is a cross section along line  15 - 15  of  FIG. 14 . 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    Referring to  FIG. 1 , the environment of the present invention is illustrated with a liquid containment vessel  10  submerged in which is a robotic cleaning vehicle  20  connected to an electrical power source  30  by an electrical supply cable  40  whose segments  42  and  44  are joined by a cable connector housing structure  50 . 
         [0023]    Referring to  FIG. 2 , one embodiment involves a cable connector housing structure  50  which has a male housing  60  which is partially inserted into a female housing  70 . The male housing  60  carries a series of detents  61  on its outside surface arranged to provide an unobstructed circular path. The female housing  70  carries a series of protuberances  71  which engage the detents  61  thus holding the two housings  60  and  70  together against axial displacement. These protuberances  71  have a sloped rear surface  73  which allows them to be drawn out of the detents  61  upon the application of an axial separating force provided that their ability to move in the radial direction away from the axis of the housings  60  and  70  is not inhibited. The housings  60  and  70  each have a cable support structure  62  and  72 , respectively. These structures  62  and  72  serve to support the cable segments  44  and  42 , respectively, when the cable segments  44  and  42  are inserted into the housings  60  and  70 . The cable support structures  62  and  72  each have an inner bore  64  and  74 , respectively, and each of these has an end  65  and  75 , respectively. These inner bore ends  65  and  75  are touching thus providing support for the ends of the cable segments  44  and  42 . The housings  60  and  70  carry recesses  66  and  76 , respectively, which carry cable grasping sleeves  90  and  100 , respectively. These sleeves  90  and  100  are constructed of a compressible material and have corrugations about their circumference running in the axial direction to aid in their grasping the cable segments  44  and  42 . The male housing  60  carries a groove  68  in which is an O-ring  80  to provide a water tight seal between the two housings  60  and  70 . In one embodiment a four-lobed X-ring is used instead of the O-ring. X-rings are commercially available as Quad-Ring® seals. End caps  110  and  120  are threaded on housings  60  and  70  by their female screw threads  112  and  122 , respectively. These end caps  110  and  120  have inclined surfaces  114  and  124 , respectively, which press against the grasping sleeves  90  and  100 , respectively, causing them to firmly grasp the cable segments  44  and  42 , respectively. A locking sleeve  130  is in position over the protuberances  71  preventing them from moving in the radial direction away from the axis of the housings  60  and  70  and being drawn out of the detents  61  by their sloped rear surfaces  73  upon the application of an axial separating force. The locking sleeve  130  is provided with a release tab  132  which facilitates taking it out of engagement with a detent  61  in the male housing  60  when it is desired to move the locking sleeve  130  to an unlocked position. The end caps  110  and  120  seat against rubber washers  140  and  150 , respectively. 
         [0024]    Referring to  FIG. 3 , one embodiment involves the two housings  60  and  70  being separated from each other. The locking sleeve  130  is therefore in its unlocked position and the protuberances  71  of the female housing  70  are not seated in the detents  61  of the male housing  70 . The other elements are as they were in  FIG. 2  except that the inner bore ends  65  and  75  no longer touch. In one embodiment the outside cylindrical body of the female housing  70  has axial slots  77  which facilitate the radial movement of its protuberances  71  into and out of engagement with the detents  61  of the male housing  60 . One of these slots  77  aligns with the protuberance  134  carried by locking sleeve  130  allowing this protuberance  134  to engage one of the detents  61  in the male housing  60 . 
         [0025]    Referring to  FIG. 4 , one embodiment involves the male housing  60  partially inserted into the female housing  70 , as in  FIG. 2  but with the locking sleeve  130  in its unlocked position. This is the configuration intermediate between those shown in  FIG. 2  and  FIG. 3 . It is the configuration just after the male housing  60  is inserted into the female housing  70  or just before the male housing  60  is withdrawn from the female housing  70  by the application of an axial force which draws the protuberances  71  out of the detents  61  by a sliding and lifting action facilitated by the sloped rear surfaces  73 . 
         [0026]    Referring to  FIG. 5 , one embodiment involves the female housing  120  equipped with fingers  164  which interact with the ribs  171  of its cable-grasping sleeve  100 . The fingers  164  extend outward from the housing&#39;s male threads  79 . The fingers  164  have outer surface  176 . The ribs  171  have an inward taper  184 . 
         [0027]    Referring to  FIG. 6 , this embodiment involves the fingers  164  having a secured end  166  adjacent to the threads  79  and a free end  168  which taper to form a reduced diameter  180 . There are gaps  174  between the adjacent fingers  164  to accommodate the ribs  100  of the cable-grasping sleeve  100 . The taper  184  of the ribs  171  terminates in a collar  182 . 
         [0028]    Referring to  FIG. 7 , the collar  182  extends radially outward from the cylindrical surface  170  of the cable-grasping sleeve  100 . The diameter of this collar  182  is such that when the fingers  164  of the housing  120  are mated with the cable-grasping sleeve  100 , as shown in  FIG. 5 , there outer surfaces  180  are radially inward of this diameter and their free ends  168  are axially immediately adjacent to this collar  182 . 
         [0029]    Referring to  FIGS. 8 and 9 , one embodiment involves interaction between the end cap  120 , the fingers  164  and the cable-grasping sleeve  100  firmly grasp a cable segment  42  and to provide a watertight seal around it. Before the female threads  122  of the end cap  120  engage the male threads  79  of the female housing  70  the outer surface of the fingers  164  define a diameter  178  when not at the taper at the free end  168  where a smaller diameter  180  is defined. The end cap  120  is provided with a collar  183  and a taper  185  on its bore. When the two threads  79  and  122  fully engage the fingers  164  are levered inward from their secured ends  166  so that their free ends press into the cable-grasping sleeve  100  causing it to firmly grasp the cable segment  42  and its collar  182  to assume an O-ring configuration seated against the ledge  183  of the end cap  120 . 
         [0030]      FIG. 10  is a cross section along line  10 - 10  of  FIG. 9  that also shows the cable grasping assembly engaging the cable segment  42 . The outer surfaces  176  of the fingers  164  define a diameter  178  to which the ridges  171  conform. 
         [0031]    Referring to  FIG. 11 , one embodiment involves a cable grasping assembly involving the male housing  60 . It has fingers  164  with secured ends  166 , free ends  168  and gaps  174 . The secured ends  166  project out from the male threads  69  and provide a first diameter  178 . The free end  168  provide a second, smaller diameter  180 . The housing  60  has molding apertures  190  which facilitate the molding of the housing  60  and are sealed by the rubber washer  140  when the end cap  110  has been secured to the housing  60  by the male threads  69 . The fingers  164  define a cavity  172  that accommodates the cable-grasping sleeve  90  with the exception of its ridges  173 , which are accommodated by the gaps  174 . When secured together the assembly firmly grasps the cable segment  44  and provides a watertight seal around it. 
         [0032]    Referring to  FIG. 12 , in one embodiment the female housing cable sleeve  100  has a cylindrical outer surface and a collar  182 . 
         [0033]    Referring to  FIGS. 13-15 , one embodiment involves the fingers  164  having an inner surface  175  especially adapted to interact with the female housing cable sleeve  100  with a cylindrical outer surface. In one embodiment the sleeve  100  and the inner finger surface  175  are both a rubbery material. In one embodiment the sleeve  100  has a very high coefficient of static sliding friction with the inner surface  175  of the fingers  164 , similar to that observed between two flat pieces of common rubber. 
         [0034]    One embodiment involves constructing the sleeve  100  out of a heat shrinkable material. In this embodiment the sleeve  100  may be secured to the cable segment  42  by the application of heat. 
         [0035]    One embodiment involves a composite cable grasping sleeve in which a cylindrical sleeve inner component is initially heat shrunk onto a cable segment and then an outer sleeve component with radial ribs like that illustrated in  FIG. 7  is placed over the inner component. Either the inner component or the outer component may carry a collar  182 . 
         [0036]    In one embodiment, one or more of the elements of the housing structure  50  are fabricated from a thermoplastic material. In one embodiment the thermoplastic material is injection molded to yield one or more of the elements. In one embodiment, the housings  60  and  70 , the end caps  110  and  120  and the locking sleeve  130  are fabricated from thermoplastic materials. In one embodiment the cable grasping sleeves  90  and  100  are fabricated from an elastomeric material. 
         [0037]    In one embodiment, the housing  50  facilitates connecting cable segments  42  and  44  which run from the robotic cleaning vehicle  20  and the electrical power source  30 , respectively, such that the segments  42  and  44  may rotate with respect to each other, with a water tight connection that can be submerged in the liquid in which the vehicle  20  is submerged. In one embodiment, one cable segment is terminated with a classical stereo jack and the other is provided with a classical stereo socket such that when the jack is inserted in the socket two circuit paths two circuit paths are created. These two segments  42  and  44  are inserted through apertures in the end caps  110  and  120  into the cable support structure  62  and  72  of housings  60  and  70 , respectively, such that when the inner bore ends  65  and  75  are brought into contact with each other the jack seats within the socket to create two circuit paths. The end caps  110  and  120  are screwed onto their respective housings  60  and  70  and their inclined surfaces  114  and  124 , respectively, cause a decrease in the diameter of the cable grasping sleeves  90  and  100  causing them to grasp the cable segments  44  and  42 . The male housing  60  is partially inserted into the female housing  70  until the ends  65  and  75  of the inner bores  64  and  75  touch and the protuberances  71  of the female housing  70  seat in the detents  61  of the male housing  60 . The locking sleeve  130  is moved into locking position so that it covers the protuberances  71  of the female housing  70  and the protuberance which it carries seats in a detent  61  in the male housing  60  through a slot in the female housing  70 . The two cable segments  42  and  44  are now securely held together against any axial separation force but are free to rotate with respect to each other. In one embodiment, the release tab of the locking sleeve  130  is used to disengage the protuberance of the locking sleeve from its detent  61  in the male housing  60  and the locking sleeve  130  is moved into an unlocked position so it no longer covers the protuberances  71 . An axial separating force is applied which causes the protuberances  71  of the female housing  70  to be drawn out of the detents  61  of the male housing  60  by their sloped rear surfaces  73  and the male housing  60  is withdrawn from the female housing  70 . In this way the two cable segments  42  and  44  are separated from each other and the stereo jack is withdrawn from the stereo socket. 
         [0038]    While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.