Patent Publication Number: US-6908343-B1

Title: Earphone jack

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to an earphone jack, more particularly to an earphone jack that has a reliable construction. 
     2. Description of the Related Art 
       FIGS. 1 to 3  illustrate a conventional earphone jack  1  for use with a mating plug  2  of an electronic apparatus. The earphone jack  1  includes an insulative housing  11 , and conductive first, second, third and fourth contact members  12 ,  13 ,  14 ,  15  mounted on the insulative housing  11 . 
     The insulative housing  11  has opposite front and rear ends  1121 ,  1122 , and is formed with a plug insertion hole  112  that extends along a hole axis (A) from the front end  1121  to the rear end  1122 . The plug insertion hole  112  has a front hole section  1130  adjacent to the front end  1121  of the insulative housing  11 , and a rear hole section  1131  adjacent to the rear end  1122  of the insulative housing  11 . The insulative housing  11  is further formed with a first contact mounting portion  114  adjacent to the front end  1121  of the insulative housing  11 , and a second contact mounting portion  115  between the first contact mounting portion  114  and the rear end  1122  of the insulative housing  11 . 
     The first contact member  12  is mounted on the insulative housing  11  at the first contact mounting portion  114 , and includes a plug contacting portion  121  that extends into the front hole section  1130 , and a contact tab  122  that extends horizontally away from the insulative housing  11 . 
     The second contact member  13  is mounted on the insulative housing  11  at the second contact mounting portion  115 , and includes a plug contacting portion  131  that extends into the front hole section  1130 , and a contact tab  132  that extends horizontally away from the insulative housing  11 . 
     The third contact member  14  is mounted in the insulative housing  11 , and has a frame portion  141  disposed in the plug insertion hole  112 , and a resilient portion  142  extending upwardly and obliquely from the frame portion  141 . A contact tab  1411  extends from the frame portion  141  and outwardly of the insulative housing  11 . 
     The fourth contact member  15  is mounted in the rear hole section  1131  of the plug insertion hole  112 , and cooperates with the third contact member  14  to form a switch mechanism. Particularly, when the plug  2  is not inserted into the plug insertion hole  112 , a tip of the resilient portion  142  contacts the fourth contact member  15  to result in a closed circuit condition, as best shown in  FIG. 2 . A contact tab  151  extends from the fourth contact member  15  and outwardly of the insulative housing  11 . 
     Referring to  FIG. 3 , when the plug  2  is inserted into the plug insertion hole  112 , the plug contacting portions  121 ,  131  of the first and second contact members  12 ,  13  and the resilient portion  142  of the third contact member  14  contact different parts of the plug  2  to effect signal transmission. At the same time, the resilient portion  142  of the third contact member  14  is moved away from the fourth contact member  15  to result in an open circuit condition. 
     The following are some of the drawbacks of the aforesaid conventional earphone jack  1 :
         1. In view of the cantilever design of the plug contacting portions  121 ,  131  of the first and second contact members  12 ,  13 , the plug contacting portions  121 ,  131  are liable to deform after repeated insertion and removal of the plug  2 , which can lead to poor electrical contact with the plug  2 .   2. The resilient portion  142  is prone to break away from the frame portion  141  of the third contact member  14  due to stress concentration at the juncture of the frame and resilient portions  141 ,  142  after repeated insertion and removal of the plug  2 .   3. The retention force attributed to the resilient portion  142  and acting on the plug  2  is relatively weak due to the small contact area therebetween.       

     SUMMARY OF THE INVENTION 
     Therefore, the object of the present invention is to provide an earphone jack with are liable construction that can overcome the aforesaid drawbacks associated with the prior art. 
     Accordingly, the earphone jack of the present invention comprises an insulative housing and conductive first, second and third contact members. 
     The insulative housing has opposite front and rear ends, and is formed with a plug insertion hole that extends from the front end to the rear end. The plug insertion hole has a front hole section adjacent to the front end of the insulative housing, and a rear hole section adjacent to the rear end of the insulative housing. The rear hole section is larger than the front hole section. The insulative housing further has a top wall that extends from the front end to the rear end of the insulative housing, and first and second lateral walls disposed on opposite lateral sides of the top wall. The insulative housing is formed with a first contact mounting portion adjacent to the front end of the insulative housing, and a second contact mounting portion between the first contact mounting portion and the rear end of the insulative housing. The first contact mounting portion is formed with a U-shaped first contact mounting groove that has a top groove portion formed in the top wall of the insulative housing, and first and second lateral groove portions extending from the top groove portion and formed respectively in the first and second lateral walls of the insulative housing. The top groove portion of the first contact mounting groove is in spatial communication with the front hole section of the plug insertion hole. The second contact mounting portion is formed with a U-shaped second contact mounting groove that has a top groove portion formed in the top wall of the insulative housing, and first and second lateral groove portions extending from the top groove portion of the second contact mounting groove and formed respectively in the second and first lateral walls of the insulative housing. The top groove portion of the second contact mounting groove is in spatial communication with the front hole section of the plug insertion hole. 
     The first contact member is mounted on the insulative housing at the first contact mounting portion. The first contact member includes: a first leg portion received in the first lateral groove portion of the first contact mounting groove and engaging the first lateral wall of the insulative housing; a plug contacting portion extending laterally from the first leg portion, received in the top groove portion of the first contact mounting groove, and extending into the front hole section of the plug insertion hole; and a second leg portion extending downwardly from the plug contacting portion, received in the second lateral groove portion of the first contact mounting groove, and engaging the second lateral wall of the insulative housing. 
     The second contact member is mounted on the insulative housing at the second contact mounting portion. The second contact member includes: a first leg portion received in the first lateral groove portion of the second contact mounting groove and engaging the second lateral wall of the insulative housing; a plug contacting portion extending laterally from the first leg portion of the second contact member, received in the top groove portion of the second contact mounting groove, and extending into the front hole section of the plug insertion hole; and a second leg portion extending downwardly from the plug contacting portion of the second contact member, received in the second lateral groove portion of the second contact mounting groove, and engaging the first lateral wall of the insulative housing. 
     The third contact member has a pair of prongs that extend into the rear hole section through the rear end of the insulative housing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which: 
         FIG. 1  is an exploded perspective view of a conventional earphone jack; 
         FIG. 2  is a sectional view of the conventional earphone jack of  FIG. 1 ; 
         FIG. 3  is another sectional view to illustrate the conventional earphone jack of  FIG. 1  in a state of use; 
         FIG. 4  is an exploded perspective view of the preferred embodiment of an earphone jack according to the present invention; 
         FIG. 5  is an assembled perspective view of the preferred embodiment; 
         FIG. 6  is a sectional view of the preferred embodiment, taken along line  6 — 6  of  FIG. 5 ; 
         FIG. 7  is another sectional view of the preferred embodiment, taken along line  7 — 7  of  FIG. 5 ; and 
         FIG. 8  is a view similar to  FIG. 7 , but illustrating the preferred embodiment in a state of use. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 4 to 8 , the preferred embodiment of an earphone jack  3  according to the present invention is adapted for use with a mating plug  4  of an electronic apparatus. The earphone jack  3  includes an insulative housing  5 , and conductive first, second, third contact members  6 ,  7 ,  8  mounted on the insulative housing  5 . 
     The insulative housing  5  has opposite front and rear ends  590 ,  591 , and is formed with a plug insertion hole  52  that extends along a hole axis (a) from the front end  590  to the rear end  591 . The plug insertion hole  52  has a front hole section  53  adjacent to the front end  590  of the insulative housing  5 , and a rear hole section  54  adjacent to the rear end  591  of the insulative housing  5 . The rear hole section  54  is larger than the front hole section  53 . The insulative housing  5  further has a top wall  511  that extends from the front end  590  to the rear end  591  of the insulative housing  5 , and first and second lateral walls  512 ,  513  disposed on opposite lateral sides of the top wall  511 . The top wall  511  is formed with a pair of engaging holes  58  proximate to the rear end  591  of the insulative housing  5 . The insulative housing  5  is further formed with a first contact mounting portion  56  adjacent to the front end  590  of the insulative housing  5 , and a second contact mounting portion  57  between the first contact mounting portion  56  and the rear end  591  of the insulative housing  5 . 
     The first contact mounting portion  56  is formed with a U-shaped first contact mounting groove that has a top groove portion  561  formed in the top wall  511 , and first and second lateral groove portions  564 ,  565  extending from the top groove portion  561  and formed respectively in the first and second lateral walls  512 ,  513 . The top groove portion  561  of the first contact mounting groove is in spatial communication with the front hole section  53  of the plug insertion hole  52 . Like the first contact mounting portion  56 , the second contact mounting portion  57  is also formed with a U-shaped second contact mounting groove that has a top groove portion  571  formed in the top wall  511 , and first and second lateral groove portions  574 ,  575  extending from the top groove portion  571  and formed respectively in the second and first lateral walls  513 ,  512 . The top groove portion  571  of the second contact mounting groove is in spatial communication with the front hole section  53  of the plug insertion hole  52 , as best shown in  FIG. 6 . 
     The first contact member  6  is mounted on the insulative housing  5  at the first contact mounting portion  56 , and includes a first leg portion  61 , a plug contacting portion  62 , and a second leg portion  63 . The first leg portion  61  is received in the first lateral groove portion  564  of the first contact mounting groove, and engages the first lateral wall  512  of the insulative housing  5 . The plug contacting portion  62  extends laterally from the first leg portion  61 , is received in the top groove portion  561  of the first contact mounting groove, and extends into the front hole section  53  of the plug insertion hole  52 . The second leg portion  63  extends downwardly from the plug contacting portion  62 , is received in the second lateral groove portion  565  of the first contact mounting groove, and engages the second lateral wall  513  of the insulative housing  5 . The first contact member  6  further includes a first contact tab  64  extending horizontally from the second leg portion  63  away from the insulative housing  5 . 
     In this embodiment, the first leg portion  61  of the first contact member  6  is shorter than the second leg portion  63 , and the plug contacting portion  62  of the first contact member  6  extends upwardly and obliquely from the first leg portion  61 . Moreover, the first contact mounting portion  56  is further formed with a first stop flange  562  that extends from the first lateral wall  512  into the first lateral groove portion  564  of the first contact mounting groove, and a second stop flange  563  that extends from the second lateral wall  513  into the second lateral groove portion  565  of the first contact mounting groove. The first leg portion  61  of the first contact member  6  is formed with a first locking tab  611 , such as by punching, for engaging a bottom side of the first stop flange  562 . The second leg portion  63  of the first contact member  6  is formed with a second locking tab  631 , such as by punching, for engaging a bottom side of the second stop flange  563 . 
     The second contact member  7  is mounted on the insulative housing  5  at the second contact mounting portion  57 , and includes a first leg portion  71 , a plug contacting portion  72 , and a second leg portion  73 . The first leg portion  71  is received in the first lateral groove portion  574  of the second contact mounting groove, and engages the second lateral wall  513  of the insulative housing  5 . The plug contacting portion  72  extends laterally from the first leg portion  71 , is received in the top groove portion  571  of the second contact mounting groove, and extends into the front hole section  53  of the plug insertion hole  52 . The second leg portion  73  extends downwardly from the plug contacting portion  72 , is received in the second lateral groove portion  575  of the second contact mounting groove, and engages the first lateral wall  512  of the insulative housing  5 . The second contact member  7  further includes a second contact tab  74  extending horizontally from the second leg portion  73  away from the insulative housing  5 . 
     As best shown in  FIG. 6 , like the first contact member  6 , the first leg portion  71  of the second contact member  7  is shorter than the second leg portion  73 , and the plug contacting portion  72  of the second contact member  7  extends upwardly and obliquely from the first leg portion  71 . Moreover, the second contact mounting portion  57  is likewise formed with a first stop flange  572  that extends from the second lateral wall  513  into the first lateral groove portion  574  of the second contact mounting groove, and a second stop flange  573  that extends from the first lateral wall  512  into the second lateral groove portion  575  of the second contact mounting groove. The first leg portion  71  of the second contact member  7  is formed with a first locking tab  711 , such as by punching, for engaging a bottom side of the first stop flange  572 . The second leg portion  73  of the second contact member  7  is formed with a second locking tab  731 , such as by punching, for engaging a bottom side of the second stop flange  573 . 
     Preferably, the plug contacting portions  62 ,  72  of the first and second contact members  6 ,  7  are formed with a respective contact boss  621 ,  721  to enhance contact engagement with the plug  4 . 
     The third contact member  8  is a unitary body formed by punching, and has a base portion  83  with upper and lower edges  831 ,  832 , and a pair of prongs  81  that extend from the upper edge  831  of the base portion  83 . The prongs  81  extend into the rear hole section  54  through the rear end  591  of the insulative housing  5 , are substantially flat, form a plug insertion space therebetween, and have distal end parts  811  remote from the base portion  83  and contoured to form a restricted access into the plug insertion space. Each of the prongs  81  is formed with an engaging tab  82 , such as by punching, that extends into a respective one of the engaging holes  58  in the top wall  511  of the insulative housing  5 , thereby retaining the third contact member  8  in the insulative housing  5 . The third contact member  8  further has a set of third contact tabs  84  extending horizontally from the lower edge  832  of the base portion  83  away from the rear end  591  of the insulative housing  5 . 
     As shown in  FIG. 6 , the insulative housing  5  further has a bottom wall formed with a positioning post  59  to facilitate anchoring of the insulative housing  5  during manufacturing. Since the feature of the invention does not reside in the positioning post  59 , further details thereof will be omitted herein for the sake of brevity. 
     Referring to  FIG. 8 , when the plug  4  is inserted into the plug insertion hole  52 , the first, second and third contact members  6 ,  7 ,  8  contact different parts of the plug  4  to effect signal transmission. Particularly, due to the configurations of the first and second contact members  6 ,  7 , the plug contacting portions  62 ,  72  contacts parts of the plug  4  that are angularly and axially spaced apart relative to the hole axis (a). Moreover, the tip  42  of the plug  4  is gripped firmly by the prongs  81  of the third contact member  8  to result in a secure and reliable connection therebetween. Furthermore, since each of the first and second contact members  6 ,  7  has first and second leg portions  61 ,  63 ,  71 ,  73  that engage the lateral walls  512 ,  513  of the insulative housing  5 , stable electrical connection between each of the first and second contact members  6 ,  7  and the plug  4  can be ensured even after repeated insertion and removal of the plug  4 . 
     While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.