Abstract:
An electrical plug ( 60 ) comprising a body ( 16 ) having an end ( 40 ) carrying a plurality of first ones of corresponding pairs of male ( 14 ) and female ( 17 ) electrical connection moieties. The plug includes a sleeve ( 20 ) axially extending from the body end outwardly from the moieties. The sleeve is defined by an outer periphery and an end ( 36 ) spaced apart from the body end. Integrally molded with the sleeve is a circumferential flange ( 22 ) extending radially from the outer periphery of the sleeve at the sleeve end.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    This application claims priority to the U.S. Provisional Application No. 60/191,200, filed Mar. 22, 2000. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates to electric plug and socket assemblies and more particularly to substantially self-sealing electrical plug and socket assemblies for heavy-duty truck tractors.  
         BACKGROUND  
         [0003]    Heavy duty trucks are composed of a tractor and one or more trailers coupled in series to the rear portion of the tractor. The trailers are equipped with various electrical devices which are powered from the tractor. To establish an electrical connection between the tractor and the trailer, an electrical cable is connected between the back of the tractor and the front of the trailer. Similar connections are also made between trailers if the truck rig includes a plurality of trailers.  
           [0004]    The electrical cable has, at each end, suitable plugs configured to connect to cooperating sockets mounted, respectively, in the rear wall of the tractor cab and the front end of the trailer. The basic geometries of the electric cable plugs and the cooperating structures of the sockets are the subject of applicable SAE (Society of Automotive Engineers) standards, specifically SAE standard J560. Standardizing the geometries of the sockets and plugs ensures that any trailer can be electrically connected to any tractor using any cable assembly. SAE standard J560 is incorporated hereinto by reference.  
           [0005]    Popular cable end plug and socket arrangements are described in catalog pages 12, 15 and 16 of the current catalog (CAT100) published by Phillips Industries, 12070 Burke Street, Santa Fe Springs, Calif. 90670, which is incorporated herein by reference. According to those arrangements, the socket is adapted to mate with the plug. The plug can be molded onto the end of a seven-conductor electrical cable; see for example, Phillips Part Nos. 16-7401 and 16-7402 (catalog page 16) in which such plugs are shown mated to sockets 16-726 and 16-826, respectively. The individual conductors in that cable connect within the molded plug body to female terminals which are disposed in an array corresponding to the array of male terminals which extend from the rear of socket. The female terminals are accessible at an end wall of a cavity bounded on its sides by a sleeve which is configured internally to mate intimately with the exterior of the barrel-like rear portion of the socket. The rear portion of the socket defines a linear key portion which cooperates in a keyway formed in the sleeve to assure that the plug and the socket have the correct angular relation to each other when they are mated together. The socket has an apertured spring blade cantilevered from the rear face of a socket mounting flange; the aperture in that spring blade receives a projection on the exterior of the plug sleeve when the plug and socket are mated, thereby holding the plug and the socket in that mated engagement. The projection with which the spring blade cooperates preferably is the exterior of the sleeve keyway.  
           [0006]    The socket includes a flange which surrounds the socket barrel at its forward end and lies in a plane normal to the length of the barrel. A pair of mounting holes are formed through that flange adjacent respective sides of the socket barrel. Those mounting holes are used to mount the socket to the exterior surface of the rear wall of a truck tractor. The tractor rear wall has formed through it a corresponding pair of holes located on either side of a central larger hole which is sized to receive the barrel of the socket. A gasket, having holes through it in the same pattern as the holes in the tractor wall, also is used to mount the socket to the tractor; the gasket is interposed between the tractor wall and the socket flange, and a pair of nuts and bolts are used in the mounting holes to clamp the gasket socket to the tractor wall. The plug is then mated to the socket barrel on the other side of the tractor wall.  
           [0007]    The socket body, including its mounting flange, is made of a hard material, such as die cast metal or glass filled molded nylon. The body of the plug, on the other hand, is molded of an elastomeric material. The walls of the sleeve portion of the plug are relatively thin, and so the sleeve can stretch slightly to conform snugly to the exterior of the socket barrel as the plug and socket are mated together. It has been found, however, that despite the use of a gasket as described above and despite the snug fit between of the plug sleeve with the exterior of the socket barrel, moisture can enter into the cavity between the mated barrel and sleeve over time during use of the connection formed by the socket and the plug. That moisture can produce corrosion of the mated electrical terminals of the connection, and so cause a fault in one or more of the circuits of which the connection terminals are components. It will be appreciated that, because socket and the plug are mated together at the forward (inside) surface of the tractor wall, it is difficult to obtain access to the plug and to make repairs to it.  
           [0008]    Accordingly, there is a need for an improved socket and plug arrangement which makes their connection more secure against the entry of moisture into the cavity between the socket and the plug where their electrical terminals are located. This improvement would also assure that the socket and the plug are correctly mounted to the tractor wall in the first instance.  
         SUMMARY OF THE INVENTION  
         [0009]    The present invention provides an electrical plug and socket assembly which seeks to avoid those and other deficiencies and problems found in currently available products. A presently preferred embodiment of the new assembly is described below with reference to the accompanying drawings. The drawings depict the cooperating structures for use in establishing an electrical connection between a tractor and trailer. However, as noted below, a assembly embodying features and principles of this invention can be configured differently for use in other contexts and utilities.  
           [0010]    Generally speaking, a socket and plug assembly according to this invention includes an electrical plug comprising a body having an end carrying a plurality of first ones of corresponding pairs of male and female electrical connection moieties. The plug includes a sleeve axially extending from the body end outwardly from the moieties. The sleeve is defined by an outer periphery and an end spaced apart from the body end. Integrally molded with the sleeve is a circumferential flange extending radially from the outer periphery of the sleeve at the sleeve end.  
           [0011]    In another aspect of the present invention, the socket and plug assembly comprises a socket comprising a barrel having a first end which is surrounded by a mounting flange and a second end having a plurality of first ones of corresponding pairs of male and female electrical connection moieties. The assembly also includes a plug having a body comprising a plurality of second ones of the corresponding pair of moieties for mating with the plurality of first ones and a plug sleeve axially extending from the body outwardly from the second ones of the connection moieties. The sleeve carries a peripheral flange which has substantially the same outer perimeter shape as that of the socket mounting flange to mate in sealing contact with the mounting flange.  
       
    
    
     DESCRIPTION OF THE DRAWINGS  
       [0012]    These and other features and advantages of the present invention will be better understood by reference to the following detailed description when considered in conjunction with the accompanying drawing, wherein:  
         [0013]    [0013]FIG. 1 is a fragmentary cross-sectional elevational view of the improved socket and plug connection provided by this invention. 
     
    
     DETAILED DESCRIPTION  
       [0014]    [0014]FIG. 1 shows the an electrical plug and socket assembly  50  of the present invention installed on a rear tractor wall  11 . As shown, the plug is connected with the socket by way of a socket barrel receiving hole  12  provided in the tractor wall. When connected, the socket rear male terminals  14  are mated with plug female terminals  17 .  
         [0015]    In a preferred embodiment, the socket  10  includes a generally circumferential mounting flange  18  having a rear face  31  and a front face  32 , respectively. The socket terminals  14  extend from a front end of a socket barrel  13  which projects beyond flange front face  32 . Such a socket is similar to Phillips Part No. 16-724 described in CAT100. The mounting flange  18  is generally heptagonal and made of a hardened material, such as die cast metal or glass filled molded nylon.  
         [0016]    A socket sleeve  15  is generally annular and integrally formed from the same material as the mounting flange. The socket barrel  13  carries seven male pins (not shown) in an array per SAE standard J650. The seven pins extend into the inside of the socket sleeve  15  and form a socket into which can be plugged an end of the electrical cable connecting the tractor to a trailer. The socket is closeable by a spring loaded cap  19  hinged from the rear face  31  of the socket mounting flange  18 .  
         [0017]    The socket barrel  13  is generally circular and carries seven male terminals  14 . Terminals  14  can be the opposite end of the pins accessible in socket sleeve  15 , and so terminals  14  can be arranged in an array like that of the terminal array according to SAE standard J650. The barrel  13  is adapted to mate with a sleeve of a corresponding electrical plug  60 .  
         [0018]    The electrical plug  60  comprises a generally round body  16  optionally formed in the shape of an L-shaped elbow having a first end  40  and a second end  42 . The first end  40  carries seven female terminals  17  that extend into the body  16  in an array which matches the array of the socket terminals  14 . The body  16  is made of an elastomeric material and includes an annular sleeve  20  which axially extends from the first end  40  of the plug outwardly from the female terminals  17  to form a annular cavity  34 . The cavity  34  is of suitable diameter to receive the socket barrel  13  with a snug fit. The second end  42  of the electrical plug is coupled to a multi-conductor electrical cable.  
         [0019]    Male terminals  14  and female terminals  17  are respective moieties of axial engage/disengage electrical connector arrangements. In the practice of this invention, the position of those moieties can be reversed if desired. So long as those moieties provide axial engage/disengage cooperation, they can be of any form or design which may be desired.  
         [0020]    As shown in FIG. 1, a forward end  36  of plug sleeve  20  carries a peripheral integral flange  22  radially extending circumferentially from the outer perimeter of the sleeve 20 . The flange  22  preferably has the same outer perimeter shape as that of the perimeter of socket flange  18 . A forward face of the plug flange  22  may be adapted to have a contour which is a mirror image of the contour of the rear face  32  of the socket flange  18 . It will be recalled that the body of plug  16  is molded of an elastomeric material. The walls of the plug sleeve  20  and flange  22  are relatively thin such that those portions of the plug are readily deformable by hand. That deformability of the plug sleeve and flange makes it easy for them to be deformed and forced through the hole  12  in the tractor wall from the rear (interior) side, if desired, of the tractor wall so that the plug flange forward surface can abut the rear surface of the tractor wall circumferentially about hole  12 . Accordingly, the sleeve  20 , as so disposed in hole  12 , can return to its as-molded shape.  
         [0021]    The connection of the socket to the plug is completed by inserting the socket barrel  13  into the cavity  34  in the plug sleeve to cause mating of the socket and plug terminals and mating of the forward face of the socket flange  18  with the rear face of plug flange  122 . The connection is mechanically secured together by bolts and nuts, the bolts passing through corresponding holes formed in the socket flange, the tractor wall, and the plug flange. In that way the plug flange is securely clamped between the tractor wall and the socket flange to hermetically seal the space between the socket barrel and the plug sleeve and body.  
         [0022]    An orienting key projection  38  can be defined in the exterior of the socket barrel  13  for cooperation with a mating keyway  42  in the inner surface of the plug sleeve  20 .  
         [0023]    It also is within the scope of this invention that the plug flange  22  can be made larger in size and area than the socket flange  18 . In that instance, the outer margins of the plug sleeve can be formed to fit over the edges of the socket sleeve, as shown in the accompanying drawings.  
         [0024]    The preceding description of the use of this invention has been in the context of the mounting of a socket to the rear wall of a truck tractor. Persons knowledgeable about the heavy duty truck industry will readily understand and appreciate that similar improvements in socket mountings can be applied to the mounting of electrical sockets to the rear ends of trailers adapted to be used in tandem truck rigs. The advances and improvements provided for mounting of electrical sockets in trucks can also be used in the mounting of sockets to the front ends of trailers even if the trailer front end socket connections include circuit breaker arrays associated with the sockets. Such circuit breaker arrays are mounted on a carrier which also mounts the socket electrical terminals to which SAE standard J560 is pertinent. That carrier can have mounted to it, as by bonding, an elastomeric molding which has features analogous to plug sleeve  20  and plug flange  22  and which also seals against the rear end of the socket body about the array of terminals mounted to the carrier. Persons knowledgeable about the heavy duty truck industry also will appreciate and grasp the ready adaptability of this invention to the mounting of electrical connection sockets to dollies which are used to support and to secure trailers in tandem truck rigs. Those dollies have their own brake and brake light systems.  
         [0025]    The foregoing references to existing products of Phillips Industries have been used only for the sake of convenience and brevity of explanation of this invention; such references are not to be interpreted or construed as limitations or restrictions upon the scope of this invention.  
         [0026]    It is believed that the best utility of this invention is in the context of original manufacture of truck tractors, trailers and dollies, as opposed to the modification or repair of existing tractors, trailers and dollies where the invention also has utility.  
         [0027]    While the invention is disclosed in conjunction with specific embodiments thereof, it is to be evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations as falling within the spirit and broad scope of the appended claims.