Abstract:
An audio jack includes a casing member defining an interior space having an opening. A cover is fixed to the casing member to seal the opening. Two sets of conductive terminal members are fixed in the interior space. Each set has a stationary member and a movable member that engages with the stationary member and is selectively disengageable therefrom. A plug receptacle is formed on the casing member for reception of a plug. A passage is defined inside the casing member for guiding the insertion of the plug. The insertion of the plug into the interior space establishes physical/electrical engagement with the movable members and forces the movable members to disengage from the stationary members. The cover has a barb engaging an opening defined in the casing and two resilient legs having barbed ends engaging shoulders formed on the casing thereby securely fixing the cover to the casing member. A positioning pin is provided on the cover to be forcibly fit into a hole defined in the casing member.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to an electrical connector, and in particular to an audio jack type connector for transmitting audio signals. 
     2. The Prior Art 
     As the computer and information industries develop, the transmission frequency of audio signals increases in computer and information processing systems. Electrical connectors are developed to facilitate transmission of such high frequency audio signals. Examples of such connectors are disclosed in U.S. Pat. No. 5,075,518 and Japanese patent publication No. 5-90863. The device of U.S. Pat. No. 5,075,518 includes three conductive terminal members for electrically engaging a mating connector and comprises a complicated structure. The Japanese patent discloses an audio jack having five conductive terminal members that are not securely arranged therein. 
     It is thus desirable to have an audio jack with a simple structure capable for effectively securing conductive terminal members therein. 
     SUMMARY OF THE INVENTION 
     Accordingly, an object of the present invention is to provide an audio jack having a simple structure. 
     Another object of the present invention is to provide an audio jack having conductive terminal members securely fixed therein. 
     To achieve the above objects, an audio jack in accordance with the present invention comprises a casing member defining an interior space having an opening. A cover is fixed to the casing member to seal the opening. Two sets of conductive terminal members are fixed in the interior space. Each set has a stationary member and a movable member that engages with the stationary member and is selectively disengageable therefrom. A plug receptacle is formed on the casing member for reception of a plug. A passage is defined inside the casing member for guiding the insertion of the plug. The insertion of the plug into the interior space establishes physical/electrical engagement with the movable members and forces the movable members to disengage from the stationary members. The cover has a barb engaging an opening defined in the casing and two resilient legs having barbed ends engaging shoulders formed on the casing thereby securely fixing the cover to the casing member. A positioning pin is provided on the cover to be forcibly fit into a hole defined in the casing member. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be apparent to those skilled in the art by reading the following description of a preferred embodiment thereof, with reference to the accompanying drawings, in which: 
     FIG. 1 is an exploded view of an audio jack constructed in accordance with the present invention; 
     FIG. 2 is another exploded view of the audio jack of the present invention taken from a different perspective; 
     FIG. 3 is a top plan view of a first casing member of the audio jack of the present invention; 
     FIG. 4 is a top plan view of the first casing member with conductive terminal members mounted therein; 
     FIG. 5 is an assembled view of FIG. 1; and 
     FIG. 6 is an assembled view of FIG.  2 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings and in particular to FIGS. 1 and 2, wherein an audio jack constructed in accordance with the present invention is shown, the audio jack of the present invention comprises a first casing member  1  and a second casing member  3 , both made of nonconductive material. The first casing member  1  has a bottom face  120  having four edges from which a front wall  110 , a rear wall  130  and two lateral walls  150  extend. An interior space  146  is defined between the walls  110 ,  120 ,  130 ,  150 . The first casing member  1  also has a top face  140  forming an opening of the interior space  146 . 
     The front wall  110  has a plug receptacle  111  formed thereon for reception of a plug (not shown) for the transmission of audio signals. The plug receptacle  111  is in communication with the interior space  146 . The bottom wall  120  of the first casing member  1  has a projection  125  formed thereon. The projection  125  is receivable in a hole formed on a substrate (not shown) for positioning purposes. 
     Also referring to FIGS. 3 and 4, the first casing member  1  has a first terminal holding slot  141 , a second terminal holding slot  142 , a third terminal holding slot  143  and a fourth terminal holding slot  144  defined in the interior space  146  for respectively receiving and retaining a first conductive terminal member  210 , a second conductive terminal member  220 , a third conductive terminal member  230  and a fourth conductive terminal member  240  therein. 
     The first terminal member  210  is U-shaped and has a first limb and a second limb from which an internal contact section  212  and an external contact section  211  extend, respectively. The external contact section  211  extends out of the interior space  146  through a first channel  1411  defined in the first casing member  1  and projects beyond the first casing member  1  via an opening  121  of the first channel  1411  defined in the bottom face  120 . 
     The second terminal member  220  is U-shaped and has a first limb forming an internal contact section  222  and a second limb having an external contact section  221  extending therefrom. The internal contact section  222  is received in the second terminal holding slot  142 . The second limb of the second terminal member  220  is received in a second channel  1422  defined in the first casing member  1  and the external contact section  221  projects beyond the first casing member  1  via an opening  122  of the second channel  1422  defined in the bottom wall  120 . 
     The first limb of the first terminal member  210  is resilient and biases the internal contact section  212  to engage with the internal contact section  222  of the second terminal member  220 . Preferably, the internal contact section  222  comprises a plurality of projections  223  for facilitating electrical engagement between the internal contact sections  212 ,  222  of the first and section terminal members  210 ,  220 . In this respect, the first terminal member  210  may be regarded as a movable member, while the second terminal member  220  is a stationary member. The movable member  210  is selectively separated from and electrically disengaged from the stationary member  220 . 
     The third terminal member  230  is U-shaped and has a first limb from which an internal contact section  232  extends and a second limb from which an external contact section  231  extends. The external contact section  231  extends out of the interior space  146  though a third channel  1433  defined in the first casing member  1  and projects beyond the first casing member  1  via an opening  123  of the third channel  1433  defined in the bottom wall  120 . 
     The fourth terminal member  240  is U-shaped and has a first limb forming an internal contact section  242  and a second limb having an external contact section  241  extending therefrom. The internal contact section  242  is received in the fourth terminal holding slot  144 . The second limb of the fourth terminal member  240  is received in a fourth channel  1444  defined in the first casing member  1  and the external contact section  241  projects beyond the first casing member  1  via an opening  124  of the fourth channel  1444  defined in the bottom wall  120 . 
     The first limb of the third terminal member  230  is resilient and biases the internal contact section  232  to engage with the internal contact section  242  of the fourth terminal member  240 . Preferably, the internal contact section  242  comprises a plurality of projections  243  for facilitating electrical engagement between the internal contact sections  232 ,  242  of the third and fourth terminal members  230 ,  240 . Similarly, the third terminal member  230  may be regarded as a movable member, while the fourth terminal member  240  is a stationary member. The movable member  230  is selectively separated from and electrically disengaged from the stationary member  240 . 
     In the embodiment illustrated, the first casing member  1  comprises two solid portions  16 ,  17  formed in the interior space  146  and spaced from each other to define a central passage  18  therebetween. The first and second terminal holding slots  141 ,  142  are defined in the solid portion  16  and the third and fourth terminal holding slots  143 ,  144  are defined in the solid portion  17 . The central passage  18  is substantially aligned and in communication with the plug receptacle  111  for accommodating the insertion of the plug. The internal contact sections  212 ,  232  of the first and third terminal members  210 ,  230  partially project into the central passage  18 . Thus, the insertion of the plug actuates engagement between the plug and the first and third terminal members  210 ,  230  and deflects the first limbs of the first and third terminal members  210 ,  230  whereby the internal contact sections  212 ,  232  of the first and third terminal members  210 ,  230  are separated from the internal contact sections  222 ,  242  of the second and fourth terminal members  220 ,  240 . Preferably, the solid portions  16 ,  17  have an arcuate surface  160 ,  170  bounding the central passage  18  for facilitating insertion of the plug that is usually cylindrical. 
     A grounding terminal member  250  is U-shaped and fits over an internal wall  145  formed inside the interior space  146 . The grounding terminal  250  has an internal contact section  252  extending from a first limb thereof. The internal contact section  252  extends into the central passage  18  for contacting the plug. The grounding terminal member  250  also has a second limb from which an external contact section  251  extends. The external contact section  251  projects out of the first casing member  1 . 
     In the embodiment illustrated, one of the lateral faces  150  of the first casing member  1  is provided with a slot  151  at a location corresponding to the internal wall  145  for receiving the second limb of the grounding terminal member  250 . The slot  151  is preferably T-shaped or dovetail-shaped for securely retaining the second limb of the grounding terminal member  250  therein. A recess  152  is defined in the lateral face  150  in communication with the slot  151  to form a shoulder  153  engageable by an inward barb  253  formed on the second limb of the grounding terminal member  250  for fixing the grounding terminal member  250  on the internal wall  145  of the first casing member  1 . 
     Also referring to FIG. 5, the external contact sections  211 ,  221 ,  231 ,  241 ,  251  of the first, second, third, fourth and grounding terminal members  210 ,  220 ,  230 ,  240 ,  250  that project out of the first casing member  1  are bent and shaped to lie substantially in a common plane thereby allowing the audio jack of the present invention to be surface mounted to a printed circuit board. 
     The second casing member  3  which serves as a cover for the top opening side of the first casing member  1  is received in the opening of the interior space  146  to substantially seal the interior space  146  and form a continuous surface with the top wall  140  of the first casing member  1 . Therefore, a periphery  315  of the second casing member  3  is fittingly engaged in the opening between the front, rear and lateral walls  110 ,  130 ,  150  of the first casing member  1 . 
     The second casing member  3  has a bottom side  310  positionable on the solid portions  16 ,  17  to securely retain the terminal members  210 ,  220 ,  230 ,  240  in position in the terminal holding slots  141 ,  142 ,  143 ,  144 . The second casing member  3  also has a top side  320  opposite the bottom side  310 . A positioning pin  311  is formed on the bottom side  310 . The pin  311  is forcibly fit into a corresponding hole  147  defined in the first casing member  1  for attaching the second casing member  3  to the first casing member  1 . 
     The second casing member  3  comprises a barb  312  and the front wall  110  of the first casing member  1  is provided with an opening  112  for receiving and engaging with the barb  312 . The engagement between the periphery  315  of the second casing member  3  and the walls  110 ,  130 ,  150  of the first casing member  1 , together with the barb  312  engaging the opening  112  of the first casing member  1 , effectively prevents relative displacement of the second casing member  3  with respect to the first casing member  1  in a direction substantially parallel to the second casing member  3 . 
     The second casing member  3  also comprises two resilient legs  313  extending from the bottom side  310  thereof. The legs  313  are provided with a barb  314  that engages a corresponding shoulder  134  formed on the rear face  130  of the first casing member  1 . Thus, relative displacement of the second casing member  3  with respect to the first casing member I is prevented in a direction substantially normal to the second casing member  3 . 
     Preferably, the rear face  130  is provided with two vertical slots  133  in which the shoulders  134  are formed. The slots  133  receive the legs  313  therein and the barbs  314  engage the shoulders  134 . Thus, the second casing member  3  is securely fixed to the first casing member  1 . The first casing member  1  and the second casing member  3  together substantially enclose the terminal members  210 ,  220 ,  230 ,  240 . 
     Preferably, the second casing member  3  is provided with two spaced, elongate ribs  316 ,  317  on the bottom side  310  thereof. The ribs  316 ,  317  further define the central passage  18  to facilitate insertion of the plug. Preferably, the ribs  316 ,  317  have arcuate faces corresponding to the arcuate surfaces  160 ,  170  of the solid portions  16 ,  17  of the first casing member  1 . 
     Preferably, the second casing member  3  is provided with openings  321  (FIGS. 2 and 6) corresponding to each resilient leg  313 . The openings  321  allow a user to insert an elongate object (not shown) therein for disengaging the barbs  314  from the shoulders  134  of the first casing member  1 . 
     In the embodiment illustrated, during insertion, the plug first contacts the grounding terminal member  250  and then contacts the internal contact sections  212 ,  232  of the first and third terminal members  210 ,  230 . Thus, the internal contact sections  212 ,  232  of the first and third terminal members  210 ,  230  are separated from the internal contact sections  222 ,  242  of the second and fourth terminal members  220 ,  240  thereby disconnecting the first and third terminal members  210 ,  230  from the second and fourth terminal members  220 ,  240 . 
     Although the present invention has been described with reference to a preferred embodiment thereof, it is apparent to those skilled in the art that there are a variety of modifications and changes that may be made without departing from the scope of the present invention which is intended to be defined by the appended claims.