Patent Publication Number: US-6908345-B2

Title: Electric connector and socket connector

Description:
TECHNICAL FIELD 
     The present invention relates to an electric connector including, for example, a base connector fixed onto a surface of a base and a socket connector extractable from the base connector along a direction orthogonal to the base, as well as to the socket connector. 
     BACKGROUND ART 
     The recent years have seen a dramatic proliferation of cellular phones and PHS (Personal Handyphone System). In the case of the cellular phone and the like, a user having purchased a device needs to mount a connector of an integral battery to a connector of a base or the like. Furthermore, when the life of the battery expires, the user usually replaces it with a new one. 
     Thus, the connector is mounted or removed by such a user who is not accustomed to the handling of the connectors. There may be a case where an inadequate connection between contacts results from an inadequate coupling between the connectors. If an excessive force is applied to extract the socket connector, the contact or the base may be damaged. 
     On the other hand, there is a demand for a connector having a low profile when mounted. A top-type connector assembly wherein the socket connector is extracted upward from the base connector generally has a great height of the whole connector bodies because electric wires are also located at an upper portion of the assembly. 
     A side-type connector assembly wherein the socket connector is extracted laterally from the base connector can achieve the reduction of the height of the whole connector bodies because the electric wires also extend laterally. However, it is practically difficult to laterally extract the socket connector in a state where the connector assembly is incorporated into a device. 
     In this connection, an increasing number of cellular phones employ a system wherein the socket connector is extracted upward whereas the wires extend laterally. The system is a so-called compromise between the above types of connector assemblies. 
     In the compromise system, however, the socket connector is difficult to extract because the direction of extracting the socket connector differs from the direction in which the wires extend. Furthermore, there is a fear of damaging both the connectors by forcibly extracting the socket connector. 
     DISCLOSURE OF THE INVENTION 
     A preferred embodiment of the invention for achieving the above object comprises a base connector including a base housing defining an inserting space accommodating a plurality of contacts, and fixed onto a mounting surface; and a socket connector including a socket housing accommodating a plurality of contacts, and an electric conductor extending from the socket housing in a direction generally parallel with the mounting surface. When removed from the base connector, the socket connector is extracted from the inserting space of the base connector along a predetermined extracting direction generally orthogonal to the mounting surface. The base connector and socket connector each include a cam surface, the cam surfaces capable of matching with each other. The cam surfaces serve to convert an extracting force on the socket connector into a force directed in the predetermined extracting direction, the extracting force applied via the electric conductor to the socket connector in the direction generally parallel with the mounting surface when the socket connector is removed from the base connector. 
     According to the embodiment of the invention, if the electric conductor is pulled to extract the socket connector, a force component acting generally parallel with the mounting surface can be converted into the force directed in the predetermined extracting direction by means of the cam surfaces. Accordingly, the socket connector may be smoothly extracted without causing an excessive load on both the connectors. When, on the other hand, the socket connector is mounted in place, the corresponding cam surfaces function to guide insertion of the socket connector thereby ensuring a reliable mounting of the socket connector. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic perspective view showing a base connector of an electric connector according to one embodiment of the invention; 
         FIG. 2  is a schematic perspective view showing a socket connector of the electric connector; 
         FIG. 3  is a plan view showing the base connector; 
         FIG. 4  is a sectional view taken on the line IV—IV in  FIG. 3 , omitting the hatching for representing the sections of a contact; 
         FIG. 5  is a plan view showing the socket connector; 
         FIG. 6  is a front view showing a socket housing; 
         FIG. 7  is a sectional view taken on the line VII—VII in  FIG. 5 ; 
         FIG. 8  is a front view showing a terminal; 
         FIG. 9  is a sectional view showing the connectors in connection, omitting the hatching for representing the sections of the terminal and contact; 
         FIG. 10  is a side view showing the connectors in perfect connection; 
         FIG. 11  is a side view of the connectors showing a process where a forward extracting force applied via a lead is converted into a force directed in an extracting direction X 2  for extracting the socket connector; and 
         FIG. 12  is a schematic plan view of the connectors showing a state where the extracting force applied via the lead acts laterally of the socket connector. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     A preferred embodiment of the invention will be described with reference to the accompanying drawings. 
       FIGS. 1 and 2  are schematic perspective views showing a base connector and a socket connector included in an electric connector according to one embodiment of the invention.  FIG. 10  is a side view showing the electric connector wherein both the connectors are in connection. Referring to these figures, the electric connector  1  includes a base connector  4  fixedly soldered onto a mounting surface  3  of a base  2 , and a socket connector  6  forming a pair with the base connector  4  and inserted in or extracted from an inserting space  5  of the base connector  4 . The electric connector  1  is used for connection between a base such as of a cellular phone, PHS or the like and a battery. 
     Referring to  FIGS. 1 and 2 , the inserting space  5  of the base connector  4  opens along a direction orthogonal to and away from the mounting surface  3  of the base  2  (the direction representing a direction X 2  for extracting the socket connector  6 ) as well as along a forward direction Y which is parallel with the mounting surface  3 . 
     The socket connector  6  is inserted into the inserting space  5  of the base connector  4  along an inserting direction X 1  orthogonal to the mounting surface  3 , and is extracted from the inserting space  5  along the extracting direction X 2  orthogonal to the mounting surface  3 . The socket connector  6  includes leads  7 , as an electric conductor, generally extending in the forward direction Y. 
     When the socket connector  6  is removed from the base connector  4 , the leads  7  may sometimes be pulled along a direction other than the extracting direction X 2 . However, the embodiment of the invention has a primary feature that when the leads are pulled along a direction other than the extracting direction, the tension via the leads  7  is converted into a force directed in the direction X 2  for extracting the socket connector  6  such that the socket connector  6  may be smoothly extracted without causing twist. 
       FIG. 3  is a plan view showing the base connector  4  whereas  FIG. 4  is a sectional view taken on the line IV—IV in FIG.  3 . Referring to  FIGS. 1 ,  3  and  4 , the base connector  4  includes a base housing  8 , which includes a base  9  fixed onto the mounting surface  3 , a rear wall  10  and a pair of lateral side walls  11 ,  12  which upstand from the base  9 . The inserting space  5  is defined by the rear wall  10  and the lateral side walls  11 ,  12 . 
     The inserting space  5  accommodates a plurality of plate-like contacts  13  (three contacts, for example) disposed in parallel with the side walls  11 ,  12 . Referring to  FIG. 4 , each contact  13  is retained by the base  9  and the rear wall  10  as inserted in a corresponding fixing hole  29  formed in the base  9 . The contact  13  includes a body portion  30  generally of a rectangular shape, and a lead portion  31  extending rearwardly from a lower end of the body portion  30 . The body portion  30  includes a contact portion  32  projecting upward from the base  9 , and a fixable portion  34  having press-insertion projections  33  press-inserted in the fixing hole  29 . A reference numeral  35  represents a through hole formed in the fixable portion  34  in correspondence to the press-insertion projections  33 . A reference numeral  36  represents a chamfer which is formed at an upper edge and a front edge of the contact portion  32  for facilitating the connection with a corresponding contact  14  of the socket connector  6 . 
     Each of the contacts  13  is arranged such that when the connectors  4 ,  6  are in connection, the contact  13  is retained as clamped between a pair of contact pieces  15  of a corresponding contact  14  of the socket connector  6  (see FIG.  8 ). 
     Referring to  FIGS. 1 and 3 , the rear wall  10  is formed with vertical grooves  16  which extend in line with corresponding side walls  11 ,  12 . The vertical grooves  16  are adapted to fittingly receive corresponding vertical ribs  19  (see  FIG. 6 ) on an end face  18  of the socket housing  17  when the connectors  4 ,  6  are in connection. 
     Referring to  FIGS. 1 ,  3  and  4 , the side walls  11 ,  12  are formed with fitting grooves  20  on respective inside surfaces  11   a ,  12   a  thereof, the fitting groove  20  extended vertically and located laterally of the contact  13 . The fitting grooves  20  are adapted to mate with corresponding two-step ribs  53  (see  FIGS. 2 and 6 ) formed on lateral sides  21  of the socket housing  17 . The two-step rib  53  includes an upper rib  54  of a greater thickness and a lower rib  22  of a smaller thickness. 
     Referring to  FIGS. 1 and 3 , each fitting groove  20  is shaped like an inverted triangle, progressively decreased in width toward bottom. The fitting groove  20  is defined by an inside rear wall  23  extended vertically, a cam surface  24  formed by an inside front wall extended angularly with respect to the vertical direction, and a groove bottom surface  25 . A portion of the groove bottom surface  25  that corresponds to an upper portion of the fitting groove  20  is dispensed with, so that an interior of the fitting groove  20  opens toward a lateral side of the base housing  8 . 
     Returning to  FIG. 2 , the lower rib  22  of the socket connector  6  has a cam surface  37  defining a slope of an equal inclination to that of the cam surface  24  of the base connector  4 . With the lower rib  22  fitted in the fitting groove  20  of the base connector  4 , the cam surface  37  of the lower rib  22  matches with the cam surface  24  of the fitting groove  20 , so that a tension via the leads  7  along the forward direction Y of the base connector  4 , for example, is converted into a force directed in the direction X 2  of extracting the socket connector  6 . 
     Referring to  FIGS. 1 ,  3  and  4 , the inside surfaces  11   a ,  12   a  of the side walls  11 ,  12  are each formed with a fitting projection  26  at a front-side upper place thereof. When the connectors  4 ,  6  are in connection, the fitting projections  26  fit in corresponding fitting recesses  27  in the lateral sides  21  (see  FIG. 2 ) of the socket housing  17  whereby the connection between the connectors is retained by a predetermined holding force. 
     Returning to  FIG. 1 , a reference numeral  28  represents a reinforcing tab as a metallic reinforcing member, which is press-inserted in a press-insertion groove formed at each lower front portion of the base housing  8  while having one part thereof exposed from each corresponding lateral side of the base housing  8  so as to be soldered to an electric conductive portion of the surface  3  of the base  2 . 
     Returning to  FIG. 2 , the socket connector  6  includes the socket housing  17  generally shaped like a rectangular parallelpiped. The socket housing  17  includes a plurality of terminal receiving holes  38  which are extended along an anteroposterior direction and laterally arranged.  FIG. 5  is a plan view of the socket connector whereas  FIG. 6  is an end elevation of the housing of the socket connector.  FIG. 7  is a sectional view taken on the line VII—VII in FIG.  5 . 
     Referring to  FIG. 7 , each of the terminal receiving holes  38  accommodates a terminal  39  crimped onto an end of each lead  7 . The terminal  39  includes an insulation barrel  41  crimped onto a jacket  40  of the lead  7 , a wire barrel  43  crimped onto a conductor  42  of the lead  7 , a box  44  shaped like a square ring to be fitted in an inside surface of the terminal receiving hole  38 , and the contact  14  having the aforesaid pair of contact pieces  15 . 
     A reference numeral  45  represents a lance comprising a resilient projection which engages a corresponding engagement hole  46  of the socket housing  17  for preventing the disengagement of the terminal  39  from the terminal receiving hole  38 . The engagement hole  46  opens into a top surface  47  of the socket housing  17  so that an engaging state of the lance  45  can be visually inspected from above. Each of the terminal receiving holes  38  defines an elongate slit  48  (see FIGS.  6  and  7 ), which opens to the forward end face  18  and a forward bottom surface  49  of the socket housing  17 . Each slit  48  accommodates a corresponding contact  14 . 
     Now referring to  FIG. 8  showing a front view of the terminal  39 , the contact  14  includes a pair of contact pieces  15  extended parallel with each other in opposed relation. The contact pieces  15  are each provided with a contact portion  50  on their opposite surfaces, the contact portions projecting toward each other. Each of the plate-like contacts  13  (represented by the two-dot-dash line in  FIG. 8 ) of the base connector  4  is inserted in a gap S between the pair of opposite contact portions  50 , so that the contact  13  is resiliently retained as clamped between the pair of contact pieces  15 ,  15  for ensuring contact pressure between the contacts  13 ,  14 . 
     Returning to  FIG. 2 , the socket housing  17  is formed with a frame  51  at a front portion thereof, the frame generally forming a groove opening downwardly as viewed from the front side as shown in FIG.  6 . The frame  51  includes a protrusion  52  protruded relative to the top surface  47  of the socket housing  17  serving as a pressure surface and corresponding to the position of the contacts  14 , and the aforesaid pair of two-step ribs  53  projecting from the respective lateral sides  21  of the socket housing  17 . As shown in  FIGS. 2 and 5 , a rib-like mark  58 , for example, is provided on a surface of the protrusion  52  for indicating that a portion carrying the mark should be pressed for mounting the socket connector  6 . 
     As shown in  FIG. 10 , the lower rib  22  of the two-step rib  53  fits in a lower portion (where the groove bottom portion  25  exists) of the fitting groove  20  of the base connector  4 , whereas the upper rib  54  is received by an upper portion (where the groove bottom portion  25  does not exist) of the fitting groove  20 . The coupling via the two-step ribs  53  ensures that the housings  8 ,  17  of the connectors  4 ,  6  are firmly connected together. 
     In a state where the two-step ribs  53  are fitted in the fitting grooves  20  to bring the cam surfaces  37  of the lower ribs  22  into the matching relation with the corresponding cam surfaces  24 , relieves  55  shaped like an inverted triangle are defined between the upper ribs  54  and the cam surfaces  24  of the fitting grooves  20 . 
     The embodiment of the invention is designed based on the combination of the top-type connector assembly with the side-type connector assembly having the leads  7  extended horizontally, thereby achieving a low profile of the connectors mounted on the base. Furthermore, the embodiment is arranged such that when the leads  7  are pulled along a direction other than the extracting direction X 2  in order to extract the socket connector  6 , a component of the tension that acts generally parallel with the surface  3  of the base  2  can be converted into a force directed in the extracting direction X 2  by virtue of the cam surfaces  37 ,  24 . Therefore, the socket connector  6  may be smoothly extracted without subjecting the connectors  4 ,  6  to an excessive load. The cam surfaces  37 ,  24 , in particular, are positioned laterally of the group of contacts  13 ,  14  and hence, the cam surfaces  37 ,  24  provide the converted force directed in the extracting direction X 2  which is applied to places on the opposite sides of the group of contacts  13 ,  14  and relatively close thereto. This results in a smoother extraction of the socket connector  6 . 
     When, on the other hand, the socket connector  6  is mounted in place, the cam surfaces  24 ,  37  function to guide the insertion of the socket connector  6  thereby ensuring a reliable mounting of the socket connector  6 . 
     The inserting space  5  of the base connector  4  opens both in the upward extracting direction X 2  and the forward direction Y, so that the socket connector  4  inserted in the inserting space  5  is confined by the side walls  11 ,  12  while being allowed of a degree of freedom of movement with respect the above two directions. On the other hand, the plate-like contact  13  positioned parallel with the side walls  11 ,  12  is retained as clamped between the pair of contact pieces  15 ,  15  of the corresponding contact  14 . Therefore, the socket connector  6  may be moved in either directions of the free movement without twisting the contacts  13 ,  14 . 
     If the socket connector  6  in perfect connection with the connector  4 , as shown in  FIG. 10 , is moved a little along the extracting direction X 2 , the relieves  55 ,  56  are formed on the opposite sides of the lower rib  22 , as shown in  FIG. 11 , so as to increase the freedom of movement of the socket housing  17 . As a result, it becomes easier to extract the socket connector  6 . 
     The rear wall  10  and the lateral side walls  11 ,  12  of the base connector  4  define a section of an open-ended square, while the side walls  11 ,  12  are coupled with the socket connector  6  via the two-step ribs  53 . Hence, a part of the connector housing  8  is combined with a part of the connector housing  17  via the two-step ribs  53  to form a box structure, which is effective to prevent the twisting of the housings  8 ,  17  which may cause an unwanted load on the contacts  13 ,  14 . 
     Further, the top surface  47  serving as a pressure surface to be pushed with a finger for inserting the socket connector  6  into the inserting space  5  has the protrusion  52  in correspondence to the position of the contacts  14 . Thus, whenever the socket connector  6  is mounted in place, the protrusion  52  is depressed strong enough to ensure the positive connection between the contacts  13 ,  14 . 
     As shown in  FIG. 10 , a part of the socket housing  17  projects from the side walls  11 ,  12  of the base housing  8  along the direction in which the leads  7  extend. Hence, if the leads  7  are pulled along a lateral direction of the socket housing  17  as seen in  FIG. 10  (or a direction perpendicular to a longitudinal direction of the drawing surface), the socket connector  6  may be extracted easily. This is because, as shown in the schematic diagram of  FIG. 12 , the tension produces a moment of turning the socket housing  17  about a front edge  57  of the side wall  11  (or  12 ) of the base housing  8 , the moment converted by the pair of cam surfaces  24 ,  37  on the opposite side into the force acting in the extracting direction X 2 . 
     Although the above embodiment has the arrangement wherein the socket connector is attached to the leads from a battery, the invention is not limited to this. The socket connector may be applied to any of the common repair parts that may be handled by users. 
     The electric conductor connected with the socket connector may include a solid wire, multi-core cables, flexible printed circuits such as called FPCs, flexible flat cables and the like. Other various changes and modifications may be made within the scope of the invention.