Abstract:
An electronic device of the type including a threaded female connector adapted to mate with a cable connector including a housing, a female connector extending from the housing, and a circuit board positioned within said housing and having a first presoldered conductor wire extending therefrom toward the female connector. The electronic device further includes a collet assembly positioned within a bore of the threaded female connector, wherein the collet assembly comprises a generally cylindrical insulating body having a first end and an opposed second end, an electrically conductive collet contact passing through the insulating body and having a first end proximate the first end of the insulating body and a second end proximate the second end of the insulating body. The first end of the collet contact includes a first gripping member for gripping an external conductor wire introduced into the female connector bore, and the second end of the collet contact includes a second gripping member for gripping the first presoldered conductor wire.

Description:
FIELD OF THE INVENTION 
     The present invention relates to an electronic device, including a collet assembly having an improved mechanical connection mechanism for receiving electrical conductor wires. 
     BACKGROUND OF THE INVENTION 
     The manufacture of electronic devices such as electronic filters, involves mass production assembly of a number of separate components. An example of such an electronic filter is disclosed in U.S. Pat. No. 5,662,494, the entirety of which is incorporated by reference herein. The &#39;494 filter housing  1  shown in FIG. 1 includes a female connector bore  2 , a pre-assembled collet assembly  3  positioned within the bore and having collet contact  4  extending from the collet assembly. The collet contact is secured to a circuit board  5  having discrete electronic components  6 A- 6 D. A conductor wire  7  is secured to the circuit board and extends from the circuit board through a male connector end  8  of the housing. 
     The filter is assembled using a multi-step process, comprising both efficient and inefficient assembly techniques. The discrete electronic components  6 A- 6 D and the conductor wire  7  are wave soldered to the circuit board  5  contemporaneously in their respective positions. This portion of the manufacturing process is highly efficient, as it is fully automated. 
     In order to complete the circuit board assembly of FIG. 1, the collet contact  4 , which is an integral part of the collet assembly, must also be soldered to the circuit board. The collet assembly  3  is a prefabricated unit from which the integrated collet contact  4  extends. Securing the collet contact  4  to the circuit board  5  requires a separate, hand-soldering step, because the heat generated during wave soldering would melt the plastic components of the collet assembly. This step is both inefficient and costly. 
     Although the overall structure of the filter in FIG. 1 is relatively simple and inexpensive to manufacture and assemble, the requisite hand-soldering step to secure the collet contact to the circuit board creates an additional, inefficient manual step. The need for such an extra, manual manufacturing step limits the speed and efficiency of the process technique, and increases the costs associated with the manufacture of electronic devices of this nature. 
     It would be desirable to provide an electronic device with a collet assembly to be mated with a circuit board which does not necessitate the extra, inefficient manual step required in the conventional manufacturing technique described above. It would also be desirable to increase production speed and efficiency, and decrease overall production costs by achieving more efficient automated assembly of the circuit board. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to overcome the drawbacks of the prior art, particularly to provide an electronic device having a collet assembly that can be secured to a circuit board without a separate, manual soldering step during assembly of the electronic device. 
     In accordance with a first embodiment of the present invention, an electronic device of the type including a threaded female connector adapted to mate with a cable connector is provided that includes a housing and a female connector bore extending from the housing. The filter also includes a circuit board which is positioned within the housing and has a first presoldered conductor wire extending therefrom toward the female connector bore. 
     The device of this preferred embodiment further includes a collet assembly which is positioned within the female connector bore and includes a generally cylindrical insulating body extending along a longitudinal direction from a first end thereof to an opposed second end thereof. The collet assembly also includes a collet contact which passes through the insulating body, and has a first end proximate to the first end of the insulating body and a second end proximate to the second end of the insulating body. The collet assembly further includes a first gripping member for gripping an external conductor wire introduced into the female connector bore, and a second gripping member for gripping a first presoldered conductor wire extending from the first end of the circuit board. 
     Since the second female socket receives the first presoldered conductor wire that extends from the circuit board, the first presoldered conductor wire can be wave soldered onto the circuit board along with the discrete electronic components and the second conductor wire in an automated manufacturing step. The first presoldered conductor wire can then be mechanically inserted into the second female socket of the collet contact. This eliminates the need for a separate hand-soldering step in the assembly of the electronic device. 
     In accordance with a preferred embodiment of the present invention, the first gripping member of the collet assembly is defined by a first female socket secured within the first end of the collet contact. More preferably, the first female socket comprises a band member having contact fingers extending therefrom in a longitudinal direction of the collet contact. The second gripping member is also preferably a second female socket secured within the second end of the collet contact. More preferably, the second female socket comprises a band member having contact fingers extending therefrom in a longitudinal direction of the collet contact. 
     As an alternative, one or both gripping members could be formed integrally with he collet contact in the form of an axially split and radially compressed bore. 
     In accordance with another preferred embodiment of the present invention, the insulating body of the collet assembly includes a front insulator having inner and outer surfaces, and a rear insulator having inner and outer surfaces. More preferably, the rear insulator of the collet assembly further includes a first section having a first diameter, and a second section having a second diameter, wherein a portion of the first section of the rear insulator extends within the front insulator. 
     It is also preferred that the front insulator of the collet assembly has a cylindrical sidewall having inner and outer surfaces and an end wall substantially enclosing one end of the front insulator, wherein the portion of the first section of the rear insulator is surrounded by the sidewall of the front insulator. More preferably, the front insulator further includes a plurality of longitudinally extending ridges on the inner surface of the sidewall providing contact with the first section of the rear insulator. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description of a preferred mode of practicing the invention, read in connection with the accompanying drawings, in which: 
     FIG. 1 is a cross sectional view of a prior art filter; 
     FIG. 2 is a cross sectional view of a collet assembly in accordance with one embodiment of the present invention; 
     FIG. 3 is a cross sectional view of the collet contact of FIG. 2 before the first and second female sockets are press fit therein; 
     FIG. 4A is a view showing the stamped band member and contact fingers before rolling to form the cylindrical configuration of the first female socket as depicted in FIG. 2; 
     FIG. 4B is a view of the band member and contact fingers of the first female socket after rolling to form a generally cylindrical configuration and before being press fit into the first bore of the collet contact; 
     FIG. 5A is a view showing the stamped band member and contact fingers before rolling to form the cylindrical configuration of the second female socket as depicted in FIG. 2; 
     FIG. 5B is a view of the stamped band member and contact fingers of the second female socket after rolling to form a generally cylindrical configuration and before being press fit into the second bore of the collet contact; 
     FIG. 6A is a cross sectional view of the front insulator of FIG. 2; 
     FIG. 6B is a plan view of the open end of the front insulator of FIG. 2; 
     FIG. 7A is a plan view of a collet contact in accordance with another embodiment of the present invention; 
     FIG. 7B is an end view of an extended collet contact forming a female socket in accordance with another embodiment of the present invention; and 
     FIG. 8 is a partial exploded view showing the assembly of the circuit board and the collet assembly of the present invention within a housing for an electronic device. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 2 is a cross sectional view of a collet assembly  100  in accordance with one embodiment of the present invention. The collet assembly  100  includes a front insulator  10  having a generally cylindrical sidewall  11  and an end wall  12  substantially enclosing one end of the front insulator  10 . The end wall  12  includes a guide hole  13  through which a center conductor of a cable may be introduced into the collet assembly. The collet assembly  100  also includes a rear insulator  20 , which is generally cylindrical in shape having a first section  21  having a first diameter, a second section  22  having a second diameter, and a third section  23  having a third diameter. The first section  21  of the rear insulator  20  is surrounded by the front insulator  10  and is in contact with inner ridges  14  extending longitudinally along the inner surface of sidewall  11  of the front insulator  10 . The second section  22  of the rear insulator  20  is proximate to the second end of the collet contact  30 . The third section  23  of the rear insulator  20  is positioned between the first section  21  and the second section  22 .The front insulator  10  is made from an electrically insulating material, one example of which is polypropylene. The rear insulator  20  is also made from an insulating material, one example of which is polypropylene. 
     An elastomer seal  60  is seated on the outer surface of the rear insulator  20  at the third section  23  and forms a surface compression seal as described in commonly owned U.S. Pat. No. 5,662,494 incorporated by reference herein. The elastomer seal  60  is made from an elastomer material, one example of which is rubber. 
     The collet assembly  100  also includes a collet contact  30  extending longitudinally from the front insulator  10  toward the rear insulator  20 . The collet contact  30  is made from an electrically conductive material, one example of which is brass. 
     A first female socket  40  is press fit within the collet contact  30  proximate to the front insulator  10  and extends longitudinally toward the rear insulator  20 . The first female socket  40  comprises a generally circular band member  45  (FIG. 4A) from which a plurality of contact fingers  42 A-D extend cylindrically and longitudinally within collet contact  30 . The contact fingers  42 A-D are bent inward to provide an elongated surface for contact with a conductor wire to be received therein, and to provide two points of contact between the contact fingers  42 A-D and the collet contact  30 . The contact fingers  42 A-D of the first female socket  40  are made from an electrically conductive material, one example of which is beryllium copper. 
     A second female socket  50  is press fit within the collet contact  30  proximate to the end of the rear insulator  20  and extends longitudinally toward the front insulator  10 . The second female socket  50  comprises a generally circular band member  55  (FIG. 5A) from which a plurality of contact fingers  52 A-D extend cylindrically and longitudinally within collet contact  30 . The contact fingers  52 A-D of the second female socket  50  are bent to taper inwardly along the length of the fingers to provide an elongated surface for contact with a conductor wire to be introduced therein. The contact fingers  52 A-D of the second female socket  50  are made from an electrically conductive material, an example of which is phosphor bronze. 
     The collet assembly  100  of the present invention may be appreciated in conjunction with the prior art filter of the &#39;494 patent shown in FIG.  1 . Because of the placement of the second female socket  50 , the overall length of the collet assembly  100  may be longer than the collet assembly  3  in FIG.  1 . To accommodate the longer collet assembly  100 , the female connector bore  2  of the filter housing  1  may be longer as well. The increased length of the female connector bore  2  also accommodates placement of an integral fastening device on the outside surface of the connector bore  2  as shown and described in co-pending U.S. patent application Ser. No. 09/641,989, entitled Electrical Signal Filter Housing With Hexagonal Drive Section, filed Aug. 18, 2000. 
     FIG. 3 is a cross sectional view of the collet contact  30  of FIG. 2 before the first female socket  40  and the second female socket  50  are press fit therein. A first bore  40 A is provided for receiving the first female socket  40 . A second bore  50 A is provided for receiving the second female socket  50 . 
     FIG. 4A is a view showing a substantially flat stamped piece  49  comprising a band member  45  from which the contact fingers  42 A-D extend. The flat piece  49  is rolled to form the cylindrical configuration of the female socket  40  as depicted in FIG.  2 . The length of the band member  45  must be long enough so that when it is rolled into the generally cylindrical shape of the female socket as shown in FIG. 4B, the outer diameter of the rolled band  45  is slightly greater than the inner diameter of the first bore  40 A of the collet contact  30 . This is necessary to facilitate the press fit of the rolled first female socket  40  into the first bore  40 A of the collet contact  30 . 
     Chamfer sections  44 A and  44 B are cut out on the edge of each of the contact fingers  42 A-D so that when the stamped piece is rolled, the outer profile of each contact finger is generally circular. The stamped piece  49  is made from an electrically conductive, spring tempered material, an example of which is beryllium copper. 
     FIG. 4B is a view of the band member  45  and contact fingers  42 A-D of the first female socket  40  of FIG. 2 after rolling the substantially flat stamped piece  49  of FIG. 4A to form a generally cylindrical configuration and before being press fit into the first bore  40 A of the collet contact  30 . The contact fingers  42 A-D are bent inwardly along the length of the fingers such that the cylindrical shape roughly resembles an hour glass and forms a center socket column  46  for receiving a center conductor wire. The inner diameter of the socket column  46  varies along the length of the contact fingers  42 A-D, providing a waist  46 A at the point where the distance between the converging contact fingers  42 A-D is the smallest. The inner diameter of the waist  46 A of the socket column  46  is also less than the outer diameter of the smallest center conductor wire to be received in order to facilitate electrical contact upon insertion of the wire into the socket  40 . 
     The generally cylindrical, hourglass-like shape of the first female socket  40  provides two points of contact a and b with the collet contact  30  after the socket is press fit within the first bore  40 A. The dual contact points a and b facilitate electronic communication between the collet contact and the center conductor wire. The overall resistance of the collet contact is also reduced by having each finger  42 A-D contact the inner surface of the bore  40 A at points a and b. The support provided by the dual contact points also insures more reliable retention of the mating contact with the incoming conductor wire. 
     FIG. 5A is a view showing a substantially flat stamped piece  59  comprising a band member  55  from which the contact fingers  52 A-D extend. The flat piece  59  is rolled to form the cylindrical configuration of the female socket  50  as depicted in FIG.  2 . The length of the band member  55  must be long enough so that when it is rolled into the generally cylindrical shape of the female socket as shown in FIG. 5B, the outer diameter of the rolled band  55  is slightly greater than the inner diameter of the second bore  50 A of the collet contact  30 . This is necessary to facilitate the press fit of the rolled second female socket  50  into the second bore SOA of the collet contact  30 . 
     FIG. 5B is a view of the band member  55  and contact fingers  52 A-D of the second female socket  50  of FIG. 2 after rolling the substantially flat stamped piece  59  of FIG. 5A to form a generally cylindrical configuration and before being press fit into the second bore  50 A of the collet contact  30 . The contact fingers  52 A-D are bent inwardly along the length of the fingers forming a tapered center socket column  56  for receiving a presoldered conductor wire. The inner diameter of the tapered socket column  56  varies along the length of the contact fingers  52 A-D, providing a point  56 A where the distance between the converging contact fingers  52 A-D is the smallest. The inner diameter of the point  56 A of the socket column  56  is also less than the outer diameter of the smallest presoldered conductor wire to be received in order to facilitate electrical contact upon insertion of the presoldered conductor wire into the socket  50 . 
     FIG. 6A is a cross sectional view of the front insulator  10  of FIG.  2 . The front insulator  10  includes a generally cylindrical sidewall  11  and an end wall  12  substantially enclosing one end of the front insulator. The end wall  12  includes a guide hole  13  through which the center conductor of a cable may be introduced into the collet assembly. The front insulator  10  also includes a plurality of inner ridges  14   a-d  extending longitudinally along the inner surface of sidewall  11 . FIG. 6B is a plan view of the open end of the front insulator  10  of FIG. 2, showing the plurality of ridges  14   a-d  located on the inner surface of sidewall  11 . The guide hole  13  is centered on the end wall  12 . 
     FIG. 7A is a plan view and FIG. 7B is a bottom view of a collet contact  70  in accordance with another embodiment of the present invention. The collet contact  70  is substantially cylindrical in shape. A first bore  80  is provided for receiving a first female socket, such as the first female socket  40  shown in FIG. 2. A second female socket  90  is provided by the elongated contact fingers  71 A-B which are an extension of the collet contact  70 , and which are bent to taper along the length of the contact fingers. The diameter of the female socket  90  decreases along the length of the tapered contact fingers to a neck point  91 . The inner diameter of the neck point  91  is less than the outer diameter of the smallest presoldered conductor wire to be received in order to facilitate electrical contact upon reception of the presoldered conductor wire into the socket  90 . The collet contact  70  of this embodiment of the present invention is made of an electrically conductive material, an example of which includes brass. 
     FIG. 8 is a partial exploded view showing the assembly of a circuit board  200  and the collet assembly  100  of the present invention within a housing  300  for an electronic device. The conductor wires  210  and  220  are contemporaneously wave soldered to the circuit board unit  200  as described above. The first presoldered conductor wire  210  is inserted into the collet assembly  100  by mechanical insertion into the second female socket  50  shown in FIG.  2 . The collet assembly-circuit board unit  110  is then inserted into the housing  300  such that the collet assembly  100  is positioned within the female connector bore  302  and the circuit board is positioned within the center bore  301 . 
     While the present invention has been particularly shown and described with reference to the preferred mode as illustrated in the drawings, it will be understood by one skilled in the art that various changes in detail may be effected therein without departing from the spirit and scope of the invention as defined by the claims.