Patent Publication Number: US-2009233475-A1

Title: Waterproof gigabit ethernet connector

Description:
TECHNICAL FIELD 
     The present invention relates to rugged connectors for Gigabit Ethernet applications. 
     BACKGROUND OF THE INVENTION 
     Gigabit Ethernet (GbE or 1 GigE) describes technologies for transmitting Ethernet frames at a rate of a gigabit per second, as defined by the IEEE 802.3-2005 standard. Ethernet is a physical link and link layer protocol. There are several standards for transmitting Ethernet frames over twisted pair or copper-based computer networking physical connectivity methods. Currently the most widely used of these are 10BASE-T, 100BASE-TX, and 1000BASE-T, running at 10 Mbit/s, 100 Mbit/s, and 1000 Mbit/s (1 Gbit/s) respectively. 
     The most commonly used standard of Gigabit Ethernet (1000 Mbit/s) over twisted pair is 1000BASE-T, which uses Category 5e cable. Category 5 cable, commonly known as Cat 5, is a twisted pair style cable designed for high signal integrity. IEEE 802.3ab defines standards for 1000BASE-T over category  5  cable. Category 5 has been superseded by the Category 5e specification which is formally defined in the TIA/EIA-568-B standard. Category 5e cable is often used in structured cabling for computer networks such as Ethernet, and is also used to carry many other signals such as basic voice services, token ring, and ATM. 
     An 8 Position 8 Contact (8P8C hereinafter) modular connector may be coupled to each free end of a category  5   e  cable for transmitting data packets at Gigabit rates. An 8P8C connector is most commonly used for 100 Mbit/s networks, such as 100BASE-TX Ethernet. Under the naming scheme, an 8P8C connector has eight positions, each associated with a conductor. 8P8C connectors are commonly used for single Ethernet applications, basic voice services, token ring, and ATM, and have replaced many older connector types. Gigabit Ethernet applications may optionally use 8P8C modular connectors, which are commonly referred to as RJ45 in the context of Ethernet over twisted pair. 
     An 8P8C modular connector (e.g., RJ45) has two forms: the male plug and the female receptacle or jack, each having eight conductors. RJ45 connectors may not be sufficiently robust to withstand moisture, pressure, shock and/or vibration. In view of the foregoing, there is a continuing need to further develop and refine connectors intended for Gigabit Ethernet applications, in the interest of functionality, utility and performance. 
     SUMMARY OF THE INVENTION 
     According to an aspect of the invention, a mateable pair of Ethernet connector assemblies for propagating data at Gigabit rates is provided. The pair of electrical connector assemblies comprises a male Ethernet plug and a female Ethernet receptacle. The male Ethernet plug includes a substantially cylindrical hollow-body shell, an insulator body positioned within the shell and defining a mating surface, and a plurality of cylindrical pins positioned within respective apertures formed in the insulator body. One end of each pin extends beyond the mating surface of the insulator body for insertion into a respective socket of the female receptacle, and a threaded region positioned on or adjacent the shell for threadedly coupling to the female receptacle. 
     The female Ethernet receptacle includes a substantially cylindrical hollow-body shell, an insulator body positioned within the receptacle shell and defining a mating surface, and a plurality of hollow-body cylindrical sockets positioned within respective apertures formed in the receptacle insulator body. One end of each socket is substantially flush with the mating surface of the receptacle insulator body for receiving a pin of the male Ethernet plug, and a threaded region positioned on or adjacent the receptacle shell for threadedly coupling to the threaded region of the plug shell. 
     According to another aspect of the invention, a male Ethernet plug assembly for propagating data at Gigabit rates is provided. The plug assembly comprises a substantially cylindrical hollow-body shell, an insulator body positioned within the shell and defining a mating surface, and a plurality of cylindrical pins positioned within respective apertures formed in the insulator body. Adjacent cylindrical pins are spaced apart by a pre-determined distance. One end of each pin extends beyond the mating surface of the insulator body by a predetermined length for insertion into a socket of the female Ethernet receptacle. The opposing end of each pin is configured to be coupled to an electrical wire. A threaded region is positioned on or adjacent the shell for threadedly coupling to a female Ethernet receptacle. 
     According to yet another aspect of the invention, a female Ethernet receptacle assembly for propagating data at Gigabit rates is provided. The receptacle assembly comprises a substantially cylindrical hollow-body shell, an insulator body positioned within the shell and defining a mating surface, and a plurality of hollow cylindrical sockets positioned within respective apertures formed in the insulator body. Adjacent sockets are spaced apart by a pre-determined distance. One end of each socket is substantially flush with the mating surface of the receptacle insulator body for receiving a pin of a male Ethernet plug. An opposing end of each socket is configured to be coupled to an electrical wire. A threaded region is positioned on or adjacent the shell for threadedly coupling to the male Ethernet plug. 
     According to still another aspect of the invention, a twisted pair cable assembly for propagating data at Gigabit rates is provided. The twisted pair cable assembly comprises a first twisted pair cable having at least eight conductors, and a second twisted pair cable having at least eight conductors. A male Ethernet plug includes at least eight cylindrical pins, each pin having one end for insertion into a respective socket of a female Ethernet receptacle and an opposing end coupled to a respective conductor of the first twisted pair cable. The female Ethernet receptacle includes at least eight hollow-body cylindrical sockets, each socket having one end for receiving a pin of the male Ethernet plug and an opposing end coupled to a respective conductor of the second twisted pair cable. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The invention is best understood from the following detailed description when read in connection with the accompanying drawing. It is emphasized that, according to common practice, the various features of the drawing are not to scale. Included in the drawing are the following figures: 
         FIG. 1A  depicts an end view of a receptacle of a cable assembly according to one exemplary embodiment of the invention. 
         FIG. 1B  depicts a cross section of the cable assembly of  FIG. 1A  taken along the lines  1 B- 1 B. 
         FIG. 2A  depicts an end view of a plug of a cable assembly according to one exemplary embodiment of the invention. 
         FIG. 2B  depicts a cross section of the cable assembly of  FIG. 2A  taken along the lines  2 B- 2 B. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     This invention will now be described with reference to several embodiments selected for illustration in the drawings. It will be appreciated that the scope and spirit of the invention are not limited to the illustrated embodiments. 
     Referring generally to the figures, a mateable pair of Ethernet connector assemblies  12  and  32  for propagating data at Gigabit rates is disclosed. The pair of Ethernet connectors include female Ethernet receptacle assembly  12  (hereinafter receptacle assembly  12 ) and male Ethernet plug assembly  32  (hereinafter plug assembly  32 ). The receptacle assembly  12  is illustrated in  FIGS. 1A and 1B , and plug assembly  32  is illustrated in  FIGS. 2A and 2B . The plug assembly  32  and receptacle assembly  12  are releasably engageable for transferring signals at Gigabit rates as well as power, such as from a DC source (not shown). 
     Referring now to  FIGS. 1A and 1B ,  FIG. 1A  depicts an end view of receptacle assembly  12  of cable assembly  10  according to one exemplary embodiment of the invention, and  FIG. 1B  depicts a cross section of cable assembly  10  of  FIG. 1A  taken along the lines  1 B- 1 B. The cable assembly  10  generally includes a receptacle assembly  12  crimped, soldered, or otherwise fastened onto an electrical cable  14 , and an optional strain relief  18  coupled to cable  14  and receptacle assembly  12 . 
     The receptacle assembly  12  comprises a substantially cylindrical hollow-body shell  20 , an insulator body  21  positioned within shell  20 , and a plurality of hollow cylindrical sockets  24  positioned within respective apertures  25  formed in insulator body  21 . The exposed end of each socket  24  is maintained substantially flush with mating surface  22  of insulator body  21  for receiving a pin of plug assembly  32 . The opposing end of each socket  24  is configured to be coupled to a single conductor  16  of electrical cable  14 . Specifically, each conductor  16  is crimped, soldered, or otherwise coupled, to the end of a respective socket  24 , as shown. 
     The insulator body  21  is cup-shaped and includes a plurality of apertures  25  that are sufficiently spaced apart for accommodating sockets  24 . A single socket  24  is positioned within a single aperture  25 . The insulator body  21  electrically insulates, i.e. isolates, sockets  24  from one another to reduce EMI and cross-talk. The insulator body  21  may be formed from polycarbonate for dry applications, polyurethane and epoxy for underwater applications, or any other material known to those skilled in the art. 
     The insulator body  21  includes a recessed portion  26  for accommodating conductors  16  of electrical cable  14 . An insulative epoxy compound  27  is applied within recessed portion  26  of insulator body  21  to maintain sockets  24  and conductors  16  in a fixed position. The insulative epoxy compound  27  seals and protects the electrical connections between each socket  24  and conductor  16 . 
     According to one aspect of the invention, receptacle assembly  12  optionally includes at least eight (8) sockets  24  for respective connection with eight (8) conductors  16  of cable  14 . The cable  14  may be classified as Category 5e, Category 6, or any other style known to those skilled in the art for propagating signals (Ethernet or otherwise) and power. Because Category 5e and Category 6 cable includes a total of (or a minimum of) eight (8) conductors and receptacle assembly  12  accommodates Categories 5e and 6 cable, receptacle assembly  12  includes at least eight (8) sockets  24 . The receptacle assembly  12  may also have nine (9) sockets  24 , as shown, for carrying Ethernet signals, master time reference signals and power circuits. 
     According to one aspect of the invention, sockets  24  are cylindrically shaped contacts composed of a conductive metallic material. According to one aspect of the invention, each socket  24  is manufactured consistent with MIL-C-39029/63C revision dated Oct. 28, 1993. Each socket  24  includes an aperture having a diameter of about 0.0415 inches for receiving a pin  44  of plug assembly  32  (see  FIG. 2B ). 
     As best shown in  FIG. 1B , adjacent sockets  24  are spaced apart by a pre-determined distance “D.” According to one aspect of the invention, the pre-determined distance “D” is maintained between about 0.08 inches to about 0.2 inches, or more preferably maintained at about 0.110 inches. Maintaining the pre-determined distance “D” between about 0.08 inches to about 0.2 inches minimizes the separation between conductors  16  connected to those sockets  24 . 
     Minimizing separation between conductors  16  maintains conductors  16  in a twisted state. Numerous benefits are achieved by maintaining conductors  16  in a twisted state. Twisted pair cabling is a form of wiring in which two conductors are wound together for the purposes of canceling out electromagnetic interference (EMI) from external sources, electromagnetic radiation, and crosstalk between neighboring pairs. Twisting wires decreases interference because the loop area between the wires, which determines the magnetic coupling into the signal, is reduced. In balanced pair operation, the two wires typically carry equal and opposite signals (differential mode) which are combined by addition at the destination. When pairs are not twisted, one member of the pair may be closer to the source than the other, and thus exposed to slightly different induced EMI. Accordingly, spacing adjacent sockets  24  by a pre-determined distance “D” is beneficial for minimizing separation between conductors  16  to maintain conductors  16  in a twisted state. 
     According to one aspect of the invention, receptacle assembly  12  is configured to be releasably mateable with plug assembly  32  for transferring power and data at Gigabit rates. The receptacle assembly  12  includes provisions for releasably coupling with plug assembly  32 . More particularly, a square-shaped alignment tab  28  is formed on an outer revolved surface of shell  20  for mating with a recess  38  (See  FIG. 2A ) of plug assembly  32 . The tab  28  slides along the internal surfaces of recess  38 . In assembly, tab  28  is aligned with recess  38  prior to mating pins  44  of plug assembly  32  with sockets  24  of receptacle assembly  12 . 
     The tab  28  and recess  38  alignment features are provided to facilitate alignment between the pins  44  of plug assembly  32  and respective sockets  24  of receptacle assembly  12  to prevent misalignment and/or potential damage to pins  44  and respective sockets  24 . Those skilled in the art will recognize that plug assembly  32  may include alignment tab  28  and receptacle assembly  12  may include recess  38  (See  FIG. 2A ) without departing from the scope or spirit of the invention. 
     The receptacle assembly  12  includes a cylindrically-shaped nut  29  for releasably fastening to plug assembly  32 . The nut  29  is slideably captivated to shell  20  and rotates with respect to shell  20  for mating receptacle assembly  12  to plug assembly  32  after insertion of pins  44  into respective sockets  24 . According to one aspect of the invention, nut  29  is permanently captivated (i.e., non-removable) to shell  20 . 
     The nut  29  includes a threaded region (not shown) defined on an interior surface thereof for threadedly engaging exterior threaded region  52  of plug assembly  32  (see  FIG. 2B ). According to one aspect of the invention, the threaded region (not shown) is positioned adjacent shell  20 . Those skilled in the art will recognize that receptacle assembly  12  may include a threaded region positioned on shell  20  (similar to threaded region  52 ) and plug assembly  32  may include a slideably captivated nut having internal threads adjacent shell  40  (similar to nut  29 ) without departing from the scope or spirit of the invention. Furthermore, those skilled in the art will also recognize that other ways exist to releasably couple receptacle assembly  12  with plug assembly  32 . 
     The exterior surface of nut  29  is knurled, as shown, to allow easy hand tightening or loosening of nut  29 . The nut  29  may also include a hex shaped surface, or other surface, for receiving a wrench. 
     The optional strain relief  18  is mounted to cable  14  and receptacle assembly  12  for absorbing mechanical forces applied to cable  14 . One end of strain relief  18  includes a threaded region (not shown) for coupling to threads  23  of shell  20 . The opposing end of stain relief  18  includes a strap  17  positioned about the perimeter of cable  14 . Two fasteners  19  are fastened to strap  17  of strain relief  18  and a fixed component (not shown) for strain relieving cable  14 . 
     Referring now to  FIGS. 2A and 2B ,  FIG. 2A  depicts an end view of plug assembly  32  of cable assembly  30  according to one exemplary embodiment of the invention, and  FIG. 2B  depicts a cross section of cable assembly  30  of  FIG. 2A  taken along the lines  2 B- 2 B. The cable assembly  30  generally includes a plug assembly  32  crimped, soldered, or otherwise fastened onto an electrical cable  34 . Although not shown, cable assembly  30  may optionally include a strain relief for absorbing mechanical forces applied to cable  34 . 
     The plug assembly  32  comprises a substantially cylindrical hollow-body shell  40 , an insulator body  42  positioned within shell  40 , and a plurality of cylindrical pins  44  positioned within respective apertures  46  formed in insulator body  42 . The pins  44  are releasably engageable with respective sockets  24  for establishing an electrical connection between cable  34  and cable  14 . As compared with traditional RJ45 connectors, the pin and socket design described herein limits loss of data packets during shock and vibration. More particularly, upon exposure to vibration or shock, loss of electrical contact between the pins and sockets is minimized by virtue of the contact therebetween. 
     One end of each pin  44  extends beyond mating surface  48  of insulator body  42  by a predetermined length “L” for insertion into a respective socket  24  of receptacle assembly  12 . According to one aspect of the invention, the predetermined length “L” is between about 0.1 inches and 0.35 inches. Additionally, by virtue of the predetermined length “L,” plug assembly  32  is configured to propagate Ethernet signals at Gigabit rates. The opposing end of each pin  44  is configured to be coupled to a single conductor  36  of electrical cable  34 . Specifically, each conductor  36  is crimped, soldered, or otherwise coupled, to the end of a single pin  44 . 
     As best shown in  FIG. 2A , adjacent pins  44  are spaced apart by a pre-determined distance “D.” The pre-determined distance “D” is equivalent to the pre-determined distance “D” shown in  FIG. 1A , such that pins  44  align and mate with sockets  24 . According to one aspect of the invention, the pre-determined distance “D” is maintained between about 0.08 inches to 0.2 inches, or more preferably maintained at 0.110 inches. Maintaining the pre-determined distance “D” between about 0.08 inches to 0.2 inches minimizes the separation between conductors  36  connected to those pins  44 . As noted previously, minimizing separation between conductors  36  maintains conductors  36  in a twisted state, which reduces electromagnetic interference (EMI) from external sources, electromagnetic radiation, and crosstalk between neighboring pairs. 
     According to one aspect of the invention, plug assembly  32  optionally includes at least eight (8) pins  44  for respective connection with eight (8) conductors  36  of cable  34 . The cable  34  may be classified as Category 5e, Category 6, or any other cable style known to those skilled in the art for propagating signals (Ethernet or otherwise) and power. As stated previously, because Category 5e and Category 6 cable include a total of (or a minimum of) eight (8) conductors and plug assembly  32  accommodates Categories 5e and 6 cable, plug assembly  32  includes at least eight (8) pins  44 . The plug assembly  32  may also include nine (9) pins, as shown, for carrying Ethernet signals, master time reference signals and power circuits. 
     According to one aspect of the invention, pins  44  are cylindrically shaped contacts composed of a conductive metallic material. Each pin  44  may be manufactured consistent with MIL-C-39029/64C revision dated Feb. 10, 1992, for example. The diameter of each pin  44  may be 0.04 inches for insertion into socket  24  of receptacle assembly  12 . 
     Similar to insulator body  21  of  FIG. 1B , insulator body  42  is cup-shaped and includes a plurality of apertures  46  (nine shown) disposed on a surface thereof for receiving pins  44 . The apertures  46  are sufficiently spaced apart for electrically insulating the pins  44  from one another to reduce EMI and cross-talk and to maintain conductors  16  in a twisted state. 
     The insulator body  42  further includes a recessed portion  49  for accommodating conductors  36  of electrical cable  34 . An insulative epoxy compound  50  is applied within recessed portion  49  of insulator body  42  to maintain pins  44  and conductors  36  in a fixed position. The insulative epoxy compound  50  seals and insulates the electrical connections between each pin  44  and conductor  36 . The insulator body  42  may be formed from polycarbonate for dry applications, polyurethane and epoxy for underwater applications, or any other material known to those skilled in the art. 
     The plug assembly  32  includes provisions for releasably coupling with receptacle assembly  12 . More particularly, recess  38  is formed on an interior revolved surface of shell  42  for mating with alignment tab  28  of plug assembly  32 , as described previously with reference to  FIG. 1B . The plug assembly  32  includes a threaded region  52  positioned on (or adjacent to) shell  42 . In assembly, tab  28  is positioned within recess  38  and shell  20  of receptacle assembly  12  is positioned within shell  42  of plug assembly  32 . Once pins  44  are sufficiently mated with sockets  24 , nut  29  of receptacle assembly  12  is threaded onto threaded region  52  of shell  40  until end surface  60  of nut  29  bears against flange  54  of plug assembly  32 . 
     The flange  54  extends from the exterior revolved surface of shell  42  and is oriented perpendicular to a longitudinal axis of shell  42  and proximal to threaded region  52 . The flange  54  includes a recess  56  revolved about flange  54  for accommodating a circular o-ring  58 . Rotating nut  29  onto threaded region  52  compresses end surface  60  of nut  29  with o-ring  58 , creating a waterproof or moisture-proof seal therebetween. Limiting the introduction of moisture at the interface between o-ring  58  and surface  60  prevents electrical shorting of pins  44  and sockets  24 . 
     Accordingly, the connector assemblies  12  and  32  may be utilized for underwater applications, such as outboard of a submarine or undersea systems on oil and gas exploration platforms. The connector assemblies  12  and  32  may also be utilized for surface or inboard applications of ships, submarines, tanks and aircraft and land systems. 
     According to one aspect of the invention, the mated cable assemblies  10  and  30  are rated to propagate voltage of less than or equal to 5 volts, and current of less than or equal to 1 milliamp. While the connector assemblies  12  and  32  described herein may be tailored for propagating Ethernet signals, the connectors are not limited to such use. 
     Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the spirit of the invention.