Abstract:
An audio jack designed to be wedged between a printed circuit board and a fixed portion of an electronic device in which it is mounted, thereby obviating the need to solder contacts thereof to the printed circuit board. The audio jack includes a housing ( 1 ) and a plurality of contacts received in the housing. The housing defines a longitudinal plug-insertion hole ( 12 ) therethrough for receiving a mating plug. Each contact ( 3, 4, 5, 6 ) includes a base ( 30, 40, 50, 60 ) and a tail portion ( 32, 41, 51, 61 ). Each tail portion extends downwardly and inwardly from a bottom of the base. A contact tab ( 321, 411, 511, 611 ) is formed on a distal end of each tail portion for resiliently abutting against circuit traces of a printed circuit board.

Description:
FIELD OF THE INVENTION 
     The present invention relates to the art of electrical connectors and, particularly, to an audio jack for conveniently and reliably mounting on a printed circuit board. 
     BACKGROUND OF THE INVENTION 
     A jack normally includes an insulative housing and a plurality of terminals mounted in the housing. Each terminal usually has a contact portion for contacting a mating connector (e.g. a plug) and a mounting portion for securing the audio jack to an electronic device. 
     Such a conventional audio jack is disclosed in U.S. Pat. No. 5,919,052. In this prior art patent, a jack includes a plurality of terminals mounted in a casing. Each terminal has a contact portion and a flat mourting portion generally perpendicular to the contact portion. The mounting portion is maintained flush with a bottom cover plate for surface mounting on a printed circuit board. However, small distances between terminals are required in miniature electronic devices to minimize the overall sizes thereof. During a surface mounting process, unwanted solder bridges between adjacent mounting portions are prone to occur, resulting in short circuits. Furthermore, the surface-mounting method is troublesome and requires a high temperature, which tends to distort the printed circuit board. 
     This invention is directed to an improved audio jack having a locking means for resiliently abutting against circuit traces of a printed circuit board, which obviates distortion of the printed circuit board and formation of short circuits which otherwise might occur when the audio jack is soldered to the circuit board. 
     SUMMARY OF THE INVENTION 
     A main object of the invention is to provide a new and improved audio jack for conveniently interconnecting the audio jack with a printed circuit board. 
     Another object of the present invention is to provide an audio jack with a controlled normal force for retaining a mating plug. 
     An audio jack in accordance with the present invention comprises an insulating housing and a plurality of contacts received in the housing. The housing defines a longitudinal plug-insertion hole therethrough for receiving a mating plug. Each contact includes a base and a tail portion extending downwardly and inwardly from the base. The tail portion forms a contact tab on a distal end thereof for resiliently abutting against appropriate circuit traces on a top surface of a printed circuit board. 
     In use, the audio jack is retained between the circuit board and a portion of the electronic device, which downwardly presses the audio jack so that the contact tabs resiliently engage the appropriate circuit traces on the top surface of the printed circuit board. In this way, the audio jack is maintained in position on the circuit board without requiring solder to fix the contacts to the circuit traces. 
    
    
     Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded view of an audio jack of the present invention, wherein contacts of the audio jack are assembled together. 
     FIG. 2 is another exploded view of the present invention, particularly showing each separate contact; 
     FIG. 3 is an assembled view of the audio jack of FIG. 1; 
     FIG. 4 is a bottom view of FIG. 3; and 
     FIG. 5 is a front view of FIG.  3 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIG. 1, an audio jack according to the present invention comprises an insulating housing  1 , a pair of resilient contacts  3 , a pair of switch contacts  4 , a retention pad  5  and a grounding contact  6 . 
     Referring to FIGS. 1,  2  and  4 , the housing  1  includes a main body  10  and a cylindrical sleeve  11  forwardly extending from a front face of the main body  10 . A plug-insertion hole  12  (cf. FIG. 5) is longitudinally defined through the main body  10  and the sleeve  11  for receiving a plug (not shown) therein. 
     The main body  10  has a top wall  13 , a bottom  131 , a first sidewall  14  and a second sidewall  15  opposite the first sidewall  14 . A slot  16  is defined in the top wall  13  beside an inner side of the first sidewall  14 . A pair of cutouts  161  are respectively defined in two opposite sides of the slot  16  opposing each other. A pair of narrow slits  17  are defined in the top wall  13  far from the sleeve  11 . Two substantially rectangular openings  18  are respectively defined in the sidewalls  14  and  15 . A pair of channels  19  are respectively longitudinally defined in the inner side of the sidewalls  14  and  15 . A pair of upper notches  20  are respectively longitudinally defined in the inner side of the top wall  13  next to a corresponding channel  19 . A pair of lower notches  24  are defined through the bottom  131  and are aligned with corresponding upper notches  20 . A trough  21  is defined in the bottom  131  of the main body  10 . 
     Referring to FIGS. 1 and 2, each resilient contact  3  comprises a substantially rectangular and planar base  30 , a cantilevered spring contact arm  31  bending and reversely extending from an end of the base  30 , and a tail portion  32  downwardly and inwardly extending from a bottom of the base  30 . A substantially rectangular protrusion  301  is formed in approximately a middle of the base  30  for engaging with the opening  18  of the housing  1 . The contact arms  31  each form a curve portion  311  in substantially a middle part thereof. A contact portion  312  extends from a free end of the curve portion  311  and is substantially parallel to the base  30 . A contact tab  321  is formed on a distal end of the tail portion  32  for resiliently engaging an appropriate circuit trace on a top surface of a printed circuit board (not shown). 
     Each switch contact  4  is provided to cooperate with the contact portion  312  of a corresponding resilient contact  3 . Each switch contact  4  comprises a substantially rectangular and planar base  40  and a tail portion  41  downwardly and inwardly extending from a bottom of the base  40 . A barb  42  is formed on an upper side of the base  40  for securely fixing in a corresponding slit  17  of the housing  1 . A contact tab  411  is formed on a distal end of the tail portion  41  for resiliently engaging an appropriate circuit trace on a top surface of the printed circuit board (not shown). 
     The retention pad  5  comprises a substantially rectangular and planar base  50  and a tail portion  51  downwardly and inwardly extending from a bottom of the base  50 . An arcuate protrusion  501  is formed on the base  50  for biasing against a plug. The protrusion is formed in any known manner, such as by stamping or coining. The base  50  forms a pair of barbs  52  on opposite edges thereof for respectively latching with the corresponding cutouts  161  of the housing  1 . A contact tab  511  is formed on a distal end of the tail portion  51  for resiliently engaging an appropriate circuit trace on the top surface of the printed circuit board. 
     The grounding contact  6  comprises an elongated base  60  and a tail portion  61 . A contacting protrusion  62  is upwardly convex at an end of the base  60 . The tail portion  61  downwardly bends and laterally extends from an opposite end of the base  60 . A contact tab  611  is formed on a distal end of the tail portion  60  for resiliently engaging an appropriate circuit trace on the top surface of the printed circuit board. 
     In assembly, with reference to FIGS. 3,  4  and  5 , the resilient contacts  3  are fixed in the channels  19 , the protrusions  301  latching with the corresponding openings  18  for retaining the resilient contacts  3  in the housing  1 . The curve portions  311  project into the plug-insertion hole  12 . The tail portions  32  respectively extend downwardly and inwardly out of the housing  1 . 
     Each switch contact  4  is mounted in both a corresponding upper notch  20  and lower notch  24  and contacts the contact portion  312  of the corresponding resilient contact  3  when the plug is not inserted into the housing  1  (shown in FIG.  1 ). The barb  42  of each switch contact  4  is respectively retained in the corresponding slit  17 . The tail portions  41  each extend downwardly and inwardly out of the housing  1 . 
     The retention pad  5  is fixedly retained in the slot  16 . The barbs  52  of the retention pad  5  are respectively retained in the corresponding cutouts  161  of the slot  16 . The tail portion  51  extends downwardly and inwardly out of the housing  1 . 
     The grounding contact  6  is fixed in the trough  21  and the contacting protrusion  62  of the grounding contact  6  projects into the plug-insertion hole  12 . The tail portion  61  extends downwardly and inwardly out of the housing  1 . 
     The contact tabs  321 ,  411 ,  511  and  611  of the tail portions  32 ,  41 ,  51  and  61  substantially lie in a common plane. 
     When the plug is inserted into the housing  1  the plug pushes curve portions  311  sideways and the contact portion  312  of each resilient contact  3  is deflected to move away from the corresponding switch contact  4 , thereby breaking an electrical connection therebetween. The curve portion  311  of each resilient contact  3  contacts a corresponding constituent electrode of the plug to establish an electrical connection between the plug and the audio jack. At the same time, the contacting protrusion  62  of the grounding contact  6  and the protrusion  501  of the retention pad  5  bear against the plug. The protrusion  501  of the retention pad  5  abuts against the plug with a predetermined force. Preferably, the protrusion  501  of the retention pad  5  applies just enough force against the plug to protect the resilient contacts  3  from being overstrained by the forces exerted against them by the plug. Thus, permanent distortion of the resilient contacts  3  can be avoided. The height of the protrusion  501  of the retention pad  5  measured with respect to the base  50  can be adjusted during its manufacture by, for example, precision stamping to meet requisite criteria. 
     In use, the audio jack is retained between the circuit board and a fixed portion of an electronic device, for example, a casing of a mobile phone. By wedging the audio jack between the circuit board and a portion of the electronic device, the audio jack is downwardly pressed slightly and the contact tabs  321 ,  411 ,  511  and  611  resiliently engage with appropriate circuit traces on the top surface of the printed circuit board. In this way, the audio jack is maintained in position on the circuit board without requiring soldering of the contacts to the circuit traces. 
     It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.