Patent Publication Number: US-2003224658-A1

Title: Electrical connector

Description:
FIELD OF THE INVENTION  
       [0001] The present invention relates in general to electrical connectors, and in particular to an electrical connector having a center conductor pin for forming a press-fit electrical connection with a transmission line cable.  
       BACKGROUND OF THE INVENTION  
       [0002] Coaxial cable connectors are, of course, widely known and used for making connection between coaxial cable assemblies, or from a coaxial cable assembly to electrical equipment. Those skilled in the art recognize, however, that the process of affixing a coaxial cable connector to a cable assembly can be cumbersome and time consuming. The assembly method varies with the type of connector assembly used. Typically, the cable must be stripped to expose the cable center conductor. The center conductor may then be soldered or crimped to a center conductor of the connector. Once the cable center conductor is soldered to the center conductor of the connector, the cable braid may be secured to the connector and a shrink-wrap dielectric may be installed over the braid. An end portion of the connector may then be mechanically secured to a body portion of the connector to complete the assembly.  
       [0003] Certainly, each of the assembly steps in attaching a coaxial cable connector to a coaxial cable must be completed accurately by a trained individual. The laborious assembly process adds to the manufacturing cost of the assembly, and thus to the end cost of the assembly to a consumer. The soldering step, in particular, requires time and expertise to ensure an appropriate electrical connection between the cable and the connector. Failure to make a reliable electrical connection between the cable center conductor and the connector center conductor can defeat the utility of the assembly. Worse yet, if the connection is intermittent, then intermittent electrical energy may be supplied on the cable assembly during use. This can result in damage to equipment and/or personal injury, especially in high-power radio frequency applications.  
       [0004] There is therefore a need for a coaxial connector that allows for facile and reliable connection to a coaxial cable.  
       SUMMARY OF THE INVENTION  
       [0005] An electrical connector consistent with the invention generally includes a body including a connector end configured to mate with a mating connector and a cable receptacle end having a cable opening therein for receiving at least a portion of a transmission line cable, such as a coaxial cable. A center conductor pin is disposed in the connector body. The center conductor pin includes a receptacle structure having portions defining a receptacle opening extending therethrough. The receptacle opening is aligned with the cable opening and is dimensioned for receiving a conductor to make electrical contact between the conductor and the center conductor pin. The conductor may be a center conductor of the cable or an adapter pin electrically connected to the center conductor of the cable.  
       [0006] One exemplary method of electrically connecting a cable connector to a transmission line cable consistent with the invention includes: providing the connector with a connector body including a cable receptacle end having a cable opening therein for receiving at least a portion of the cable; providing a center conductor pin in the body, the center conductor pin including a receptacle structure having portions defining a receptacle opening extending therethrough; and inserting the center conductor of the cable into the receptacle opening through the cable opening.  
       [0007] Another method of electrically connecting a cable connector to a transmission line cable consistent with the invention includes: electrically connecting a first end of an IQ adapter pin to a center conductor of the cable; providing the connector with a connector body including a cable receptacle end having a cable opening therein for receiving at least a portion of the cable; providing a center conductor pin in the body, the center conductor pin including a receptacle structure having portions defining a receptacle opening extending therethrough, the receptacle opening being configured to receive a second end of the adapter pin; and inserting the adapter pin into the opening. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
     [0008] For a better understanding of the present invention, together with other objects, features and advantages, reference should be made to the following description of the preferred embodiment which should be read in conjunction with the following figures wherein like numerals represent like parts:  
     [0009]FIG. 1: is a side sectional view of an exemplary connector assembly consistent with the invention;  
     [0010]FIG. 2: is a bottom view of the exemplary connector illustrated in FIG. 1 with a bottom cover removed;  
     [0011]FIG. 3: is an end view of the connector illustrated in FIG. 1 showing an opening in a center conductor pin for receiving a cable center conductor consistent with the invention;  
     [0012]FIG. 4: is top view of an exemplary center conductor pin consistent with the invention;  
     [0013]FIG. 5: is a side view of the exemplary center conductor pin illustrated in FIG. 4;  
     [0014]FIG. 6: is a bottom view of the exemplary center conductor pin illustrated in FIG. 4.  
     [0015]FIG. 7: is a side, partial-sectional view of an exemplary connector and coaxial cable assembly consistent with the invention showing a center conductor of the coaxial cable extending into a center conductor pin of the connector;  
     [0016]FIG. 8: is a side sectional view of an exemplary connector assembly consistent with the invention incorporating an adapter pin consistent with the invention;  
     [0017]FIG. 9: is a side view of an adapter pin consistent with the invention affixed to a center conductor of a coaxial cable; and  
     [0018]FIG. 10: is side, partial-sectional view of an exemplary connector and coaxial cable assembly consistent with the invention showing an adapter pin connected to a center conductor of the coaxial cable and extending into a center conductor pin of the connector. 
    
    
     DETAILED DESCRIPTION  
     [0019] The present invention will now be described in connection with an exemplary embodiment. The exemplary embodiment described herein is configured as a right angle connector. Those skilled in the art will recognize, however, that the advantages of the invention could be incorporated into many connector configurations. It is intended, therefore, that the invention not be limited to the specific embodiment described, but include any variation thereof associated with use in varied connector schemes and designs.  
     [0020] Turning to FIG. 1, an exemplary embodiment  100  of a connector consistent with the invention generally includes: a connector body  102 , a coupling nut  104 ; a dielectric insulator  106 ; a center conductor pin  108 ; a cover  110 ; a retaining gasket  112  between the coupling nut and the body, and a gasket  114 . In the illustrated exemplary embodiment, the body  102  includes a connector portion  116  configured at a right angle to a cable receptacle portion  118 , thus establishing a right angle connector configuration with a connector end  120  and a cable-receiving end  122 . Those skilled in the art will, of course, recognize that the features of the present invention are not limited right angle connectors, but may be incorporated into a variety of straight and angular connector configurations.  
     [0021] The body may be formed as an integral structure or from multiple separate and interconnecting portions. A variety of other construction and assembly configurations are possible. For example, the connector portion  116  may be constructed separately from the cable receptacle portion  118 , and then joined thereto during assembly, as shown for example in FIG. 8. In one embodiment, the body  102 , coupling nut  104 , and cover  110  may be machined from brass and plated with nickel. The center conductor pin may be formed from brass and plated with silver. The insulator portions may be formed from a known insulating material such as TEFLON.  
     [0022] In the illustrated exemplary embodiment, the center conductor pin  108  includes portions defining a receptacle opening  124  at an end thereof. The opening  124  is dimensioned for receiving a center conductor of a cable, or an adapter pin affixed to the cable center conductor. When the cable center conductor pin, or an adapter pin affixed thereto, is disposed in the opening  124  an electrical connection is made between the center conductor pin  108  and the cable center conductor. Advantageously, the electrical connection is made simply by inserting the cable center conductor, or the adapter pin attached thereto, into the opening  108 . No soldering is required to make the electrical connection between the pin  108  and the center conductor or adapter pin. This significantly reduces assembly effort, while ensuring a reliable electrical connection.  
     [0023] With reference also to FIG. 2, the body  102  includes an assembly opening  126  at an elbow thereof to facilitate assembly of the connector. In the illustrated embodiment, the pin  108  may be press fit into the insulator  106 , which includes a central opening therein for receiving the pin  108 . Axial placement of the pin  108  relative to the insulator  106  may be determined by engagement of a surface of the pin with a surface of the insulator  106 . In the illustrated embodiment, for example, engagement of the pin  108  with the insulator  106  at point A fixes the axial location of the pin relative to the insulator.  
     [0024] The assembly of the pin  108  and insulator  106  may then be press fit into opening  126 . The axial location of the pin and insulator within the opening  126  may be determined by engagement of a surface of the insulator with a surface of the body  120 . In the illustrated exemplary embodiment, engagement of the insulator with the body at point B fixes the axial locations of the pin and insulator relative to the body. Once the pin  108  and insulator  106  are assembled through opening  126 , the cover  110  may be press fit over the opening to prevent contaminants from entering the opening.  
     [0025] The engaging surfaces between the pin, insulator, and body may be positioned so that, when assembled, the opening  124  is generally in axial alignment with a cable receiving opening  128  of the cable receptacle portion  118 , as shown particularly in FIG. 3. With reference also to FIG. 7, the cable center conductor  706 , or an adapter pin affixed thereto, may enter the opening  124  in the pin  108  via the cable receiving opening  128 .  
     [0026] The cable receptacle portion may  118  be dimensioned to allow a cable braid of the coaxial cable to be installed over the exterior surface  130 , which may be knurled to resist axial movement of the braid relative to the portion  118 . The end  122  may be tapered to facilitate installation of the braid over the surface  130 . As shown, for example, in FIG. 7, when the cable center conductor is positioned in the opening  124  and the braid  700  is positioned over the exterior surface, a crimp sleeve  132  may be compressed over the braid and over an end the cable jacket  702  to secure the cable  704  to the connector  100 .  
     [0027] The coupling nut  104  may be affixed to the body by installing the retaining gasket  112  in associated annular slot  134  in the body and then positioning the nut over the body and gasket, until the gasket engages an associated slot  134  in the nut  104 . The coupling nut, of course, facilitates removable connection of the connector  100  with a mating connector to make electrical contact between the pin  108  and a center conductor pin of the mating connector. A variety of coupling mechanisms will be known to those skilled in the art. It is to be understood, therefore, that the present invention is not limited to the illustrated coupling nut or coupling mechanism. Also, although the illustrated embodiment is configured as a plug-type connector, those skilled in the art will recognize that the advantages of the present invention may also be incorporated in a receptacle-type connector.  
     [0028] Those skilled in the art will also recognize that the center conductor pin may be provided in a variety of configurations. FIGS.  4 - 6  illustrate an exemplary center conductor pin  108   a  consistent with the invention. In the illustrated exemplary embodiment, the pin  108   a  includes: an elongate shaft  400  terminating in a beveled end  402 ; a receptacle structure  404  having portions defining an opening  124   a;  and a shoulder  406  for establishing the axial position of the pin relative to an insulator by engagement of a surface on the insulator. The beveled end  402  is configured for making electrical contact with a center conductor (not shown) of a connector that mates with the connector in which the pin  108   a  is installed.  
     [0029] In the illustrated embodiment the receptacle structure includes first  408  and second  410  generally semi-spherical portions connected to a body  412  portion of the pin. The body portion  412  includes a slot  414  formed therein. The first semi-spherical portion  408  extends from the body portion  412  on one side of the slot  414 , and the second semi-spherical portion  410  extends from the body portion on another side of the slot  414 . An end slot  416  is provided between the portions  408  and  410  at the receptacle end  418  of the pin, generally in alignment with the slot  414 .  
     [0030] The end slot  416  and the slot  414  allow expansion of the opening  124   a  for receiving a cable center conductor  700  or an adapter pin affixed thereto. In one embodiment, the opening  124   a  may be dimensioned to have a diameter slightly less than the cross-sectional diameter of the cable center conductor  700  or adapter pin. In this configuration, when the center conductor pin or adapter enters the opening  124   a,  the slots  414  and  416  allow expansion of the opening and establish a spring tension of the portions  408  and  410  against the pin or adapter. A reliable electrical connection between the pin  108   a  and the center conductor pin or adapter is thus formed.  
     [0031] Those skilled in the art will recognize that the end structure  404  may be provided in a variety of configurations. In the illustrated embodiment, the end structure extends axially from the body to define an opening  124   a  having an axis that is generally perpendicular to the axis of the center conductor pin. The end structure may, however, extend radially, or from a side surface of the pin, to allow a shorter overall length for the center conductor pin. In such an embodiment, the opening may have an axis that is angularly oriented, e.g. perpendicular, to the axis of the center conductor pin, or the opening may be axially aligned with the center conductor pin in a straight or in-line connector embodiment. In addition, the shape and size of the receptacle structure may be chosen to electrically compensate for a matched electrical line.  
     [0032] Turning now to FIG. 8, there is illustrated an exemplary embodiment  800  of the present invention including an adapter pin  802 . In the illustrated embodiment, a cable receptacle portion  118   a  of the connector  800  is joined to a separate connector portion  116   a  by a press fit connection. The cable receptacle portion  118   a  includes an outer shell  804  and an insulator  806 . The end surface  808  of the outer shell engages an abutment  810  on the connector portion  116   a  to fix the position of the connector portion relative to the receptacle portion  118   a.    
     [0033] The insulator  806  includes a central opening  812  for removably receiving the adapter pin  802 . Engaging surfaces of the insulator and the adapter pin, e.g. at point C, fix the axial position of the adapter pin  802  relative to the insulator  806  to allow extension of the adapter pin  802  into the opening  124   b  of the center conductor pin  108   b.  As shown, the insulator  806  may extend inward to contact, or be in close proximity to, the center conductor pin  108   b.    
     [0034] Generally, the adapter pin  802  has a first end  814  dimensioned to extend into the opening  124   b  in the center conductor pin  108   b  with a press fit, as shown in FIGS. 8 and 10. A second end  816  of the adapter pin is includes an opening  818  dimensioned for receiving a center conductor of the coaxial cable. As shown in FIG. 9, for example, the adapter pin  802  may be affixed to a center conductor of the cable  900  by inserting the cable center conductor into opening  818  in the end  816  of the adapter pin. The adapter pin may include a solder opening  902  through an exterior surface thereof in communication with the opening  818  for receiving the cable center conductor. When the center conductor is installed in the opening  818 , the adapter pin may be soldered to the center conductor by inserting solder into the solder opening  902 .  
     [0035] Once the pin is affixed to the center conductor, the cable may be installed to the connector  800  by inserting the end  814  of the pin into the opening  124   b  in the center conductor pin, and placing the cable braid  904  over the exterior surface  130   a  of the portion  118   a.  A crimp sleeve  132   a  may then be compressed against the braid  904  and the cable jacket  906 . A shrink-wrap dielectric  908 , of the type known to those skilled in the art, may then be installed over the crimp sleeve  132   a,  over a projection  1000  on the portion  118   a,  and over a further portion of the cable jacket  906 .  
     [0036] Advantageously, an embodiment including an adapter pin allows use of a connector assembly consistent with the invention with a variety of coaxial cable sizes. To accommodate different cable sizes, an adapter pin dimensioned to receive the cable center conductor is chosen and secured to the cable center conductor. Electrical connection between the center conductor pin and the cable center conductor is then made by simply press fitting the end  814  of the adapter pin into the opening  124   b  in the center conductor pin.  
     [0037] There is thus provided an electrical connector that allows for facile and reliable assembly of a coaxial cable to the connector. The embodiments that have been described herein, however, are but some of the several which utilize this invention and are set forth here by way of illustration but not of limitation. For example, although the invention is described herein with a right angle coaxial connector, it will be readily apparent to those skilled in the art that the features of the present invention could be incorporated into a wide variety of connector designs, e.g. straight or angular connectors, triaxial connectors, etc. It is obvious that many other embodiments, which will be readily apparent to those skilled in the art, may be made without departing materially from the spirit and scope of this invention.