Patent Publication Number: US-10770807-B2

Title: Electrical receptacle for coaxial cable

Description:
FIELD OF INVENTION 
     The present invention relates to an electrical receptacle for coaxial cable. The receptacle may be a hardline connector used in CATV networks, for example, without the need for a seizure mechanism to establish an electrical connection. 
     BACKGROUND 
     A radio frequency (RF) connector is an electrical connector designed to work at radio frequencies in the multi-megahertz range. Typically, RF connectors are used in a variety of applications, such as wireless telecommunications applications, including WiFi, CATV networks, PCS, radio, computer networks, test instruments and antenna devices. 
     CATV networks allow for the delivery of video and data to consumers and businesses. The network is typically HFC (hybrid fiber coaxial) and at least some portion for delivery to the premises is coaxial (copper-based). There are various devices in the networks, such as nodes, amplifiers, splitters, and other hardware known in the art that require connecting RF coaxial cables and connectors. There are two coaxial cable categories commonly used, i.e. flexible and hardline. Hardline connectors are typically used for longer runs on poles or for underground applications. These connectors typically interface with devices through a connector called a “KS Pin,” a “⅝-24,” or a “Stinger” connector because they feature a ⅝″-24 threaded coupling and have a protruding pin. 
     A limitation in current hardware is the KS Pin and how it is terminated to a PCB within network devices, Most KS Pins are shipped with oversized pin lengths to adapt to different hardware environments. When connecting to a device, the KS Pin is trimmed using common cutting tools and a length guide on the device. As the connector is mated to the device and the threads are properly tightened, the trimmed center pin passes into the device and through a contacting device called a pin seizure mechanism. This is a simple metal stub or block attached to the PCB with a through hole for the pin and a perpendicular threaded hole to accept a seizure screw. The screw is preassembled in the stub and the user tightens to a specified torque to clamp down on the pin. The clamping force creates the electrical connection. 
     The seizure mechanism is inherently poor at a low-loss transmission of RF, especially at higher frequencies. As result, as network frequencies increased, e.g. between 1200 and 1800 MHz, the connection provided by the seizure mechanism is a barrier to effective transmission. Further, the trimmed KS Pin itself provides connection challenges. First, the variable pin length can cause electrical or mechanical issues if it is not trimmed properly. If the pin is too long, it acts similarly to an RF antenna, increasing loss, and can contact another device component, causing mechanical damage. In addition, the pin is often trimmed with a common cable cutter, which can generate a chisel-like tip to the pin that can damage mating contacts. 
     There is a need in the market for a connector that can deliver faster data and improve video content with more choice and higher resolution. Accordingly, there is a need for a device that more effectively terminates the industry-standard KS Pin to a printed circuit board (“PCB”) internal to a network device. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention may provide an electrical receptacle that comprises a conductive body with an inner surface defining an inner receiving area and a dielectric assembly received in the inner receiving area of the conductive body. The dielectric assembly may comprise an entry dielectric portion, a distal support dielectric portion opposite the entry dielectric portion, and a reduced-diameter dielectric portion therebetween. An air region may be defined between the inner surface of the conductive body and the reduced-diameter dielectric portion of the dielectric assembly. An outer conductor may be coupled to the conductive body and receive at least part of the entry dielectric portion. An inner contact of the receptacle may have a mating interface end for receiving a corresponding mating contact, a termination end for coupling to a printed circuit board or adapter contact, and an inner through bore therebetween. The mating interface end may be received in the reduced-diameter dielectric portion. The dielectric assembly positions the inner contact along a central longitudinal axis of the conductive body. 
     In some embodiments the entry dielectric portion includes an inner ramped surface for guiding the mating contact into the mating interface end of the inner contacts; the distal support dielectric portion includes a radial flange that extends to the inner surface of the conductive body; the entry dielectric portion includes another radial flange that extends to the inner surface of the conductive body; the radial flange includes a secondary air region; the reduced-diameter portion is a sleeve configured to fit over the mating interface end of the inner contact; the air region is more than half of the inner receiving area of the conductive body; the termination end of the inner contact has an increased-diameter portion for engaging the printed circuit board; the termination end of the inner contact is elongated and receives the adaptor contact; each portion of the dielectric assembly is a separate piece; the portions of the dielectric assembly are formed of at least two pieces; and/or the at least two pieces are two identical half pieces. 
     In other embodiments, an outer surface of the conductive body includes one or more longitudinal slots configured to receive an edge of the printed circuit board; the outer conductor includes a grounding portion and a retaining portion, the retaining portion may be coupled to the conductive body such that the grounding portion extends outside of the conductive body; and/or the mating contact is a KS Pin. 
     The present invention may also provide as electrical receptacle that comprises a conductive body with an inner surface defining an inner receiving area and a dielectric assembly received in the inner receiving area of the conductive body. The dielectric assembly may comprise an entry dielectric portion, a distal support dielectric portion opposite the entry dielectric portion, and a reduced-diameter dielectric portion therebetween. An air region is defined between the inner surface of the conductive body and the reduced-diameter dielectric portion of the dielectric assembly. The air region is at least half of the inner receiving area of the conductive body. An outer conductor is coupled to the conductive body and receives at least part of the entry dielectric portion. An inner contact of the receptacle has a mating interface end for receiving a corresponding mating contact, a solder end for engaging a printed circuit board, and an inner through bore therebetween, the mating interface end being received in the reduced-diameter dielectric portion. The dielectric assembly positions the inner contact along a central longitudinal axis of the conductive body. 
     In certain embodiments, the entry dielectric portion includes an inner ramped surface for guiding the mating contact into the mating interface end of the inner contacts and the distal support dielectric portion includes a radial flange that extends to the inner surface of the conductive body; the entry dielectric portion includes another radial flange that extends to the inner surface of the conductive body and each radial flange has a secondary air region; the reduced-diameter portion is a sleeve configured to fit over the mating interface end of the inner contact; the solder end of the inner contact has an increased-diameter portion for solder engagement with the printed circuit board; the solder end includes a distal step portion; an outer surface of the conductive body includes one or more longitudinal slots configured to receive an edge of the printed circuit board; the outer conductor includes a grounding portion comprising spring fingers which extend outside of the conductive body and a retaining portion comprising a radial extension for engaging a retaining ring in the inner receiving area of conductive body; the portions of the dielectric assembly are formed of two or three pieces; and/or the mating contact is a KS Pin. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein; 
         FIGS. 1A and 1B  are front and rear perspective views, respectively, of an electrical receptacle according to an exemplary embodiment of the invention; 
         FIGS. 2A and 2B  are front and rear perspective views, respectively, of the electrical receptacle illustrated in  FIGS. 1A and 1B , showing the receptacle mounted to a printed circuit board; 
         FIG. 3  is a cross-sectional view of the electrical receptacle illustrated in  FIGS. 2A and 2B ; 
         FIG. 4  is an exploded view of the electrical receptacle illustrated in  FIGS. 1A and 1B ; 
         FIG. 5  is a cross-sectional view of an electrical receptacle in accordance with another exemplary embodiment of the present invention; 
         FIG. 6  is an exploded view of the electrical receptacle illustrated in  FIG. 5 ; 
         FIG. 7  is an exploded view of an electrical receptacle in accordance with yet another exemplary embodiment of the present invention; and 
         FIG. 8  is a cross-sectional view of the electrical receptacle illustrated in  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION 
     In describing the preferred embodiments of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents that operate in a similar manner to accomplish a similar purpose. Several preferred embodiments of the invention are described for illustrative purposes, it being understood that the invention may be embodied in other forms not specifically shown in the drawings. 
     Referring to the figures, the present invention generally relates to an electrical receptacle  100  for coaxial cable that has a simplified design and improved performance, e.g. with regard to increased bandwidth, synergy with industry-standard protocols, new hardware, and higher frequency requirements, e.g. 1200 MHz up to 3 GHz, for a wider available channel bandwidth. The receptacle  100  of the present invention is configured to improve low-loss transmission of RF, especially at higher frequencies, optimize impedance (e.g. a 75 Ohm impedance), and minimize leakage of the RF signal. 
     The receptacle  100  generally comprises a conductive body  102 , a dielectric assembly  104  received in body  102 , an outer conductor  106  coupled to body  102 , and an inner contact  108  received in dielectric assembly  104 . Body  102  may have inner and outer surfaces  110  and  112 , front and rear open ends  114  and  116 , and an inner receiving area  118  therebetween. One or more longitudinal slots  119  may be located on the body&#39;s outer surface  112 , as seen in  FIGS. 1A and 1B , to facilitate the mounting of receptacle  100  to a printed circuit board  10 . In a preferred embodiment, the longitudinal slots  119  are located one either side of body  102  and are open at the front  114  to receive an edge of the printed circuit board  10 , as seen in  FIGS. 2A and 2B . An air region  120  may be defined between the body&#39;s inner surface  110  and dielectric assembly  104 , as seen in  FIG. 3 . In a preferred embodiment, air region  120  takes up at least half or more than half of the inner receiving area  118  of body  102  to optimize impedance. 
     The dielectric assembly  104  is configured to facilitate assembly and captivation of the receptacle and configured to provide mechanical robustness and large air regions to the receptacle  100  for optimal impedance. Dielectric assembly  104  is received in inner receiving area  118  of conductive body  102  and supports inner contact  108  along a central longitudinal axis L of conductor body  104 . A portion of dielectric assembly  104  may be received in outer conductor  106 . 
     Inner contact  108  may comprise a mating interface end  122 , such as a socket, for receiving a corresponding mating contact C ( FIG. 2A ), such as a KS Pin or Stinger, a termination end  124  for coupling to printed circuit board  10 , and an inner through bore  126  therebetween through which the mating contact C may extend. Inner contact  108  is preferably captivated coaxially within conductive body  104  and supported by dielectric assembly  104  to achieve optimized mechanical and electrical function of receptacle  100 . Through bore  126  allows mating contact C to extend all the way through inner contact  108 , even if mating contact C is not trimmed properly. This prevents mechanical damage to receptacle  100  that could be caused by a relatively long mating contact. Termination end  124  may be a solder end with an increased-diameter part  128  for a more robust solder attachment to printed circuit board  10 , as seen in  FIG. 3 . Termination end  124  may also have a step  129  at is most distal end and adjacent to part  128  for preventing solder migration into through bore for  126 , and possible interference with the mating contact C. 
     As best seen in  FIGS. 3 and 4 , dielectric assembly  104  may comprise an entry dielectric portion  130 , a distal support dielectric portion  134  opposite entry dielectric portion  130 , and a reduced-diameter dielectric portion  132  therebetween. The portions  130 ,  132 , and  134  of dielectric assembly  104  may be separate pieces, as seen in  FIG. 4 , which are assembled around inner contact  108  to position contact  108  within conductive body  104  along its central longitudinal axis L, as seen in  FIGS. 2B and 3 . 
     Entry dielectric portion  130  may comprise a lead-in geometry at a front end  140  and a generally cylindrical main body  142 . The front end  140  includes an inner ramped surface  144  configured to receive and guide the mating contact C, such as a KS Pin or Stinger, into receptacle  100  for engagement with a mating interface end  122  of inner contact  108 . The front end  140  may also fit inside of outer conductor  106 . 
     Reduced-diameter portion  132  may be a sleeve  146  sized to both closely cover the inner contact&#39;s mating interface end  122  and be received within main body  142  of entry dielectric portion  130 . The sleeve  146  may have an inner lip  148  at is distal end for engaging the inner contact  108 , such as via a snap-engagement. Air region  120  is preferably defined between reduced-diameter portion  132  and the inner surface  110  of conductive body  102 . 
     Distal support dielectric portion  134  may comprise a center bore  150 , through which inner contact  108  extends, and a support member  152  configured to provide support and mechanical strength to receptacle  100 . In a preferred embodiment, support member  152  is a radial flange  154  extending radially from center bore  150  to the inner surface  110  of conductive body  104 . The main body  142  of entry dielectric portion  130  may also include a support member, such as another radial flange  156 , positioned behind front end  140 . Both flanges  154  and  156  may include a secondary air region  158  defined therein. 
     Outer conductor  106  generally comprises a grounding portion  160  and a retaining portion  162 . Retaining portion  162  may be configured to engage conductive body  102 . In a preferred embodiment, retaining portion  162  is an end wall  164  received inside the front end  114  of conductive body  102  that may cooperate with a retaining ring  166  to couple outer conductor  106  to body  102 . Alternatively, end wall  164  may engage a corresponding groove in the body&#39;s inner surface  110 . Grounding portion  160  may comprises a plurality of spring fingers  168  that extend outside of the front end  114  of body  102  for grounding contact with the system&#39;s housing. The housing may be, for example, a common ground that is part of the transmission line carrying the RF ground signal from the mating KS Pin cable connector through the KS Pin port integrated in the node housing. 
       FIGS. 5 and 6  illustrated another exemplary embodiment of the present invention in which a receptacle  200  is substantially the same as receptacle  100  described above, except its dielectric assembly  204  is formed of only two portions  230  and  232 . In a preferred embodiment, the two portions are identical half pieces and may be injection molded, for example. When the two portions  230  and  232  are assembled for supporting inner contact  108 , dielectric assembly  204  comprises a front entry end  240 , a distal support end  234 , and a reduced-diameter cylindrical main body  242 , therebetween. Front end  240  may have lead-in geometry, such as an inner ramped surface  244  and distal end  234  may have a radial flange  254 , like in receptacle  100 . Main body  242  is sized to closely receive the mating interface end  122  of inner contact  108  and may have an inner lip  248  configured to engage inner contact  108 , similar to receptacle  100 . A retaining ring  260  may be provided to secure the two portions  230  and  232  of dielectric assembly  204  together. 
       FIGS. 7 and 8  illustrate yet another embodiment of the present invention in which a receptacle  300  is similar to receptacle  100 , except that it is configured to engage an adapter  20  instead of a printed circuit board. The adapter may be used when the printed circuit board in the node, for example, is not conveniently positioned by the KS Pin port. The node includes the printed circuit board to process the signal entering or exiting the node. In some cases, the signal is sent to the printed circuit board with a cable assembly routed to the printed circuit board position in the node. The adapter may convert the KS Pin interface into a common high-performance RF interface, such as “SMB” or “MCX”. This interface adapts efficiently to a small flexible cable assembly for routing within the node. 
     The conductive body  302  and inner contact  308  of receptacle  300  are elongated to accommodate the maximum length of the mating contact C. Inner contact  308  has a mating interface end  322  supported by dielectric assembly  104 , like in receptacle  100 , and a termination end  324 . Termination end  324  of inner contact  308  is configured to engage a contact  22  of the adaptor  20 , as seen in  FIG. 8 . 
     The foregoing description and drawings should be considered as illustrative only of the principles of the invention. The invention is not intended to be limited by the preferred embodiment and may be implemented in a variety of ways that will be clear to one of ordinary skill in the art. Numerous applications of the invention will readily occur to those skilled in the art. Therefore, it is not desired to limit the invention to the specific examples disclosed or the exact construction and operation shown and described. Rather, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.