Abstract:
There is provided a jack that can be easily applied to an electronic device adopting a design where an outer edge portion of a casing is formed in an arc or tapered shape.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority to Japanese Application No. 2014-132452 filed Jun. 27, 2014 which is assigned to the assignee of the present application and is incorporated by reference herein. 
     BACKGROUND 
     1. Technical Field 
     The present invention relates to a jack such as a small jack which is used to connect an external connecting terminal to an electronic device such as a mobile phone or a smartphone. 
     2. Related Art 
     Conventionally, there are electronic devices such as smartphones and portable audio players that adopt a design where an outer edge portion of a casing (set chassis) is formed in an arc or tapered shape. There is developed a jack  200  such as a small jack which is mounted on such electronic devices and is provided with a tapered sloping portion  202  at a front surface portion of a housing  201  as shown in  FIG. 10  so as to match the design of an electronic device casing (see, for example, JP 2013-85138 A). 
     Meanwhile, there is known a jack of this type having a housing made of an insulating resin and having a plug insertion portion into which a plug is inserted; and a plurality of contacts retained on the housing such that elastic contact piece portions thereof project into the plug insertion portion, and by disposing the contacts at both side portions of the housing which sandwich the plug insertion portion, a reduction in height is achieved. 
     The contacts each have a fixed piece portion fixed on both sides of the housing which sandwich the plug insertion portion; and an elastic contact piece portion supported on the fixed piece portion. A contact point at a front end of the elastic contact piece portion projects into the plug insertion portion from a side portion of the housing, and the contacts are disposed at intervals in a plug insertion direction. 
     SUMMARY 
     However, in the above-described conventional jack, when the contacts are retained on the side portions of the housing, since the inclination angle θ of the sloping portion  202  provided to the housing is naturally limited by the distance from a front end to a contact closest to the front and the height of the contact, there is a problem that the design of an outer edge portion of a casing of an electronic device to which the jack can be applied is limited. 
     In view of such a conventional problem, an object of the present invention is therefore to provide a jack that can be easily applied to an electronic device adopting a design where an outer edge portion of a casing (set chassis) is formed in an arc or tapered shape. 
     To solve the conventional problems described above and achieve the intended purpose, a first aspect of the present invention provides a jack including: a housing made of an insulating resin and having a plug insertion portion into which a plug is inserted; and a plurality of contacts retained on side portions of the housing such that contact points of the contacts project into the plug insertion portion, wherein the housing has a low-height portion on a front side thereof and is formed such that the low-height portion and a rear of the low-height portion form a step-like shape, the contacts include a low-height contact disposed at a side portion of the low-height portion; and a holding spring/contact disposed at a side portion of a rear step portion of the housing, the low-height contact has: a fixed piece portion fixed at the side portion of the low-height portion; a folded portion formed in a folded manner from an upper edge of the fixed piece portion; an elastic contact portion extending in an obliquely downward transverse direction from a front end of the folded portion; and a contact point integrally formed at a front end of the elastic contact portion, and the contact point projects into the plug insertion portion from a bottom side of the low-height portion. 
     In addition to the configuration of the first aspect, according to a second aspect of the present invention, the housing has a low-height contact accommodation portion into which the low-height contact is incorporated from an undersurface of the housing, the low-height contact accommodation portion has: a temporary fixation pressure contact portion that comes into contact with the folded portion upon incorporation of the low-height contact; and a preload portion that comes into contact with the elastic contact portion, with the low-height contact incorporated, and when the preload portion comes into contact with the elastic contact portion, the folded portion is separated from the temporary fixation pressure contact portion. 
     As described above, a jack according to the present invention includes: a housing made of an insulating resin and having a plug insertion portion into which a plug is inserted; and a plurality of contacts retained on side portions of the housing such that contact points of the contacts project into the plug insertion portion. The housing has a low-height portion on a front side thereof and is formed such that the low-height portion and a rear of the low-height portion form a step-like shape. The contacts include a low-height contact disposed at a side portion of the low-height portion; and a holding spring/contact disposed at a side portion of a rear step portion of the housing. The low-height contact has: a fixed piece portion fixed at the side portion of the low-height portion; a folded portion formed in a folded manner from an upper edge of the fixed piece portion; an elastic contact portion extending in an obliquely downward transverse direction from a front end of the folded portion; and a contact point integrally formed at a front end of the elastic contact portion. The contact point projects into the plug insertion portion from a bottom side of the low-height portion. By this, the low-height portion can be provided and the contact can be disposed at the side portion of the low-height portion. Accordingly, a space is created above the low-height portion, and by using the space the flexibility in the design of an electronic device casing is improved. 
     In addition, in the present invention, the housing has a low-height contact accommodation portion into which the low-height contact is incorporated from an undersurface of the housing. The low-height contact accommodation portion has: a temporary fixation pressure contact portion that comes into contact with the folded portion upon incorporation of the low-height contact; and a preload portion that comes into contact with the elastic contact portion, with the low-height contact incorporated. When the preload portion comes into contact with the elastic contact portion, the folded portion is separated from the temporary fixation pressure contact portion. By this, upon incorporation of the low-height contact, the low-height contact can be temporarily fixed, and after mounting, a load (preload) is always applied to the whole spring composed of the elastic contact portion and the folded portion and thus a stable contact state can be maintained with a plug. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1A  is a front view showing a jack according to the present invention,  FIG. 1B  is a plan view of the jack, and  FIG. 1C  is a longitudinal cross-sectional view of the jack; 
         FIG. 2  is a partially see-through perspective view of the jack; 
         FIG. 3  is an exploded perspective view of the jack; 
         FIG. 4A  is a front view showing a housing of  FIGS. 1A to 1C ,  FIG. 4B  is a right side view of the housing, and  FIG. 4C  is a bottom view of the housing; 
         FIG. 5A  is a front view showing an example of a low-height contact,  FIG. 5B  is a plan view of the low-height contact, and  FIG. 5C  is a left side view of the low-height contact; 
         FIG. 6A  is front view showing another example of a low-height contact,  FIG. 6B  is a plan view of the low-height contact, and  FIG. 6C  is a right side view of the low-height contact; 
         FIG. 7  is an enlarged cross-sectional view taken along line x-x of  FIG. 1B , showing a temporary fixing state of the low-height contact; 
         FIG. 8A  is an enlarged cross-sectional view taken along line y-y of  FIG. 1B , showing a state in which the low-height contact is mounted, and  FIG. 8B  is an enlarged cross-sectional view taken along line x-x of  FIG. 1B ; 
         FIG. 9  is a longitudinal cross-sectional view showing an example of a use mode of the jack according to the present invention; and 
         FIG. 10  is a side view showing an example of a conventional jack. 
     
    
    
     DETAILED DESCRIPTION 
     Next, an embodiment of a jack according to the present invention will be described based on an implementation example shown in  FIGS. 1A to 1C to 9 . Note that in the drawings reference numeral  1  indicates a jack such as a small jack, reference numeral  2  indicates an electronic device casing (set chassis) on which the jack  1  is mounted, and reference numeral  3  indicates a plug. 
     In addition, the present implementation example makes a description such that the front side in a plug insertion direction is referred to as “front”, and with reference to the up-down and left-right directions in  FIG. 1A  the up-down direction is referred to as “longitudinal” and the left-right direction as “transverse”. 
     The jack  1  has a housing  4  made of an insulating resin and having a plug insertion portion  41  into which the plug  3  is inserted; and a plurality of contacts  5  to  8  retained on side portions of the housing  4  such that contact points thereof project into the plug insertion portion  41 . The contact points of the contacts  5  to  8  come into contact with an outer region of the plug  3  inserted into the plug insertion portion  41 . 
     As shown in  FIGS. 4A to 4C , the housing  4  is integrally formed of an insulating resin and has a low-height portion  42  disposed on the front side thereof and a rear step portion  43  disposed at the rear of the low-height portion  42 . The housing  4  is formed such that the rectangular parallelepiped low-height portion  42  and rear step portion  43  having different heights form a step-like shape as viewed from the side, with a flat undersurface. 
     In addition, a sloping portion  44  which slopes from a top surface of the rear step portion  43  toward a top surface of the low-height portion  42  is formed at a portion where the low-height portion  42  and the rear step portion  43  are connected to each other. 
     The low-height portion  42  is formed in a shape where an upper half portion of a front-side portion of the housing  4  is removed, i.e., a shape where a rectangular parallelepiped structure having, at the center thereof, a round hole opened in a front surface is halved and an upper half portion thereof is removed, and has a height that is substantially half that of the rear step portion  43 . 
     The plug insertion portion  41  is configured to have a halved portion  411  where the top-surface side of the low-height portion  42  is dented semicircularly; and a holding hole portion  412  of a round hole shape which continues with the halved portion  411  in a front-rear direction. The plug  3  is inserted such that the front end side thereof is inserted into the holding hole portion  412  and the base end side thereof is inserted into the halved portion  411  with an upper half portion thereof exposed. 
     In addition, as shown in  FIGS. 3 and 4C , the housing  4  has contact accommodation portions  9  to  12  opened in the undersurface thereof which are formed at both side portions sandwiching the plug insertion portion  41 . Into the contact accommodation portions  9  to  12  are incorporated the corresponding contacts  5  to  8  from the undersurface side. 
     Note that those contact accommodation portions disposed at the low-height portion  42  are referred to as the low-height contact accommodation portions  9  and  10 , and a contact accommodation portion disposed at one side portion of the rear step portion  43  is referred to as the holding spring/contact accommodation portion  11 . The low-height contacts  5  and  6  are incorporated into the low-height contact accommodation portions  9  and  10 , and the holding spring/contact  7  is incorporated into the holding spring/contact accommodation portion  11 . 
     As shown in  FIGS. 5A to 5C and 6A to 6C , each of the low-height contacts  5  and  6  is integrally formed by performing press working on an elastic conductive metal plate, and has a fixed piece portion  51  fixed in a longitudinal direction at a side portion of the low-height portion  42 ; a folded portion  52  formed in a folded manner from an upper edge of the fixed piece portion  51 ; an elastic contact portion  53  extending in an obliquely downward transverse direction from the folded portion  52 ; a contact point  54  integrally formed at a front end of the elastic contact portion  53 ; and a connecting terminal portion  55  extending in a transverse direction from a lower edge of the fixed piece portion  51 . The folded portion  52  and the elastic contact portion  53  form a cantilever spring structure supported on the fixed piece portion  51 . 
     The fixed piece portion  51  is formed in a rectangular plate shape standing up in the longitudinal direction and has, at both side edges thereof, catching protrusions  511  and  511  for catching which are protrudingly and integrally formed therewith. The fixed piece portion  51  is formed to have a height that matches the height of both side portions of the low-height portion  42 . 
     The folded portion  52  is formed by bending a conductive metal plate in an arc shape from the upper edge of the fixed piece portion  51 , and integrally supports the elastic contact portion  53  on the front end side thereof. 
     The width in the front-rear direction of the folded portion  52  is wider than the width in the front-rear direction of a base end of the elastic contact portion  53 . The folded portion  52  has a temporary fixation step portion  521  formed at a front end edge thereof. 
     The length from the base end to front end of the elastic contact portion  53  is such a length that the front end of the elastic contact portion  53  substantially reaches the plug insertion portion  41 , i.e., the bottom of the halved portion  411 , upon incorporation of the low-height contact  5 ,  6  into the housing  4 . The contact point  54  projects into the plug insertion portion  41  from the bottom side of the low-height portion  42 . 
     The contact point  54  is integrally formed at the front end of the elastic contact portion  53  by allowing the front end of the elastic contact portion  53  to bulge by pressing. 
     Note that the low-height contact  6  is configured in the same manner as the low-height contact  5  shown in  FIGS. 5A to 5C , but since a contact position of the low-height contact  6  with the plug  3  is a front-side position, the elastic contact portion  53  is in the shape of extending obliquely forward. 
     Each of the low-height contact accommodation portions  9  and  10  has a main body accommodation hole  91  of a rectangular hole shape; and an elastic contact portion accommodation hole  92  which communicates with the main body accommodation hole  91 . The fixed piece portion  51  and the folded portion  52  are inserted into the main body accommodation hole  91 , and the elastic contact portion  53  is inserted into the elastic contact portion accommodation hole  92 . 
     In addition, in the low-height contact accommodation portions  9  and  10 , as shown in  FIGS. 1A to 1C and 4A to 4C , projection windows  94 ,  94 , and  101  communicating with the plug insertion portion  41  are disposed in a staggered manner at a bottom portion of the plug insertion portion  41 , i.e., the halved portion  411 . The contact points  54  of the low-height contacts  5  and  6  project into the plug insertion portion  41  from the bottom side of the low-height contact accommodation portions  9  and  10 . 
     As shown in  FIGS. 4C and 7 , each main body accommodation hole  91  makes a longitudinal hole opened in the undersurface, at a side portion of the low-height portion  42 . Press-fitting grooves  911  and  911  into which both side edges of the fixed piece portion  51  are press-fit are formed on the outer side of both end portions in the front-rear direction of the main body accommodation hole  91 . The catching protrusions  511  are engaged and caught in the inner surfaces of the press-fitting grooves  911 , by which the fixed piece portion  51  is fixed to the housing  4 . 
     The main body accommodation hole  91  and the elastic contact portion accommodation hole  92  are disposed such that boundary portions thereof are shifted from each other in the front-rear direction so as to match the shape of the low-height contact  5 ,  6 . By the shift in the front-rear direction, an inner surface of the main body accommodation hole  91  forms a temporary fixation pressure contact portion  93 . 
     Then, upon incorporation of the low-height contact  5 ,  6  into the low-height portion  42 , as shown in  FIG. 7 , the temporary fixation step portion  521  of the folded portion  52  comes into contact with the temporary fixation pressure contact portion  93 , by which the folded portion  52  bends. 
     By this, in the low-height contact  5 ,  6 , by a spring reaction force of the folded portion  52 , the temporary fixation step portion  521  and the fixed piece portion  51  press an inner surface of the main body accommodation portion. By the pressing force, the low-height contact  5 ,  6  is retained on the housing  4 , enabling temporary fixation of the low-height contact  5 ,  6  to the housing  4  upon assembling. Accordingly, assembling work can be smoothly performed. 
     Meanwhile, as shown in  FIG. 8A , the elastic contact portion accommodation hole  92  is made in a shape where a top surface thereof slopes from the main body accommodation hole  91  toward the central bottom side of the low-height portion  42 . The central bottom side communicates with the plug insertion portion  41  by the projection window  94 , and the contact point  54  projects into the plug insertion portion  41  through the projection window  94 . 
     Each of the projection windows  94  and  101  is formed to match the shape of the elastic contact portion  53 , and an outer opening edge portion thereof on the accommodation hole side forms a preload portion  95 . 
     As shown in  FIG. 8A , the preload portion  95  comes into contact with an area near the contact point  54  of the elastic contact portion  53 , with the low-height contact  5 ,  6  incorporated. The preload portion  95  presses the elastic contact portion  53  downward. 
     Then, when the preload portion  95  comes into contact with the elastic contact portion  53 , the folded portion  52  and the elastic contact portion  53  which are supported on the fixed piece portion  51  bend, and as shown in  FIG. 8B , the folded portion  52  is separated from the temporary fixation pressure contact portion  93 , generating a gap t between the folded portion  52  and the temporary fixation pressure contact portion  93 . 
     Note that, the low-height contact accommodation portion  10  slightly differs from the low-height contact accommodation portion  9  in the shapes of the elastic contact portion accommodation hole  92  and the projection window  101  so as to match the shape of the contact, but is configured in substantially the same manner as the low-height contact accommodation portion  9 . 
     The holding spring/contact  7  is integrally formed by performing press working on a conductive metal plate, and has a fixed piece portion  71  fixed in the longitudinal direction at a side portion of the rear step portion  43 ; an elastic contact portion  72  in the shape of being folded inward from a side edge of the fixed piece portion  71 ; and a connecting terminal portion  73  extending outward from a lower edge of the fixed piece portion  71 . A contact point  74  bulging inward is integrally formed on the front end side of the elastic contact portion  72 . 
     The holding spring/contact accommodation portion  11  communicates with the plug insertion portion  41  through a projection window  111  which is opened so as to communicate with a side surface portion of the plug insertion portion  41 . The contact point  74  projects into the plug insertion portion  41  in the transverse direction through the projection window  111 , and thereby comes into contact with an outer surface of the plug  3  inserted into the plug insertion portion  41 . 
     The holding spring/contact  7  is accommodated in the rear step portion  43 . By the elastic contact portion  72  having the shape of being folded from the side edge of the fixed piece portion  71 , the longitudinal width of the elastic contact portion  72  can have a width that matches the height of the rear step portion  43 , enabling to ensure high spring pressure. Thus, a sense of clicking upon inserting or removing the plug  3  and holding power can be obtained. 
     In the jack  1  thus configured, the low-height contact  5 ,  6  has the folded portion  52  and the elastic contact portion  53  extending in the obliquely downward transverse direction from the front end of the folded portion  52 . By the contact point  54  projecting into the plug insertion portion  41  from the bottom side of the low-height portion  42 , while a sufficient spring span is ensured, even if a downward reaction force acts from the outer surface of the plug  3 , the downward force is distributed by the provision of the folded portion  52 , enabling to reduce the load on the fixed piece portion  51 . Thus, even if the height of the fixed piece portion  51  is made lower than that of conventional ones, the downward force can be counteracted. 
     Therefore, the low-height portion  42  can be formed to have a height substantially half that of the rear step portion  43 . For example, as shown in  FIG. 9 , a space  21  inside the casing which is created by the provision of the low-height portion  42  can be used freely, increasing the degree of flexibility in the design of the electronic device casing (set chassis)  2 . 
     In addition, by separately providing the temporary fixation pressure contact portion  93  and the preload portion  95  to the low-height contact accommodation portions  9  and  10 , upon incorporation of a contact, the contact can be temporarily fixed, and a spring composed of the elastic contact portion  53  and the folded portion  52  is allowed to bend, enabling to bring a state in which a spring reaction force is always acting (preload). Thus, a stable contact state can be maintained with the plug  3  inserted into the plug insertion portion  41 . 
     Note that although the above-described implementation example describes an example in which the sloping portion  44  is provided to the housing  4 , the low-height portion  42  and the rear step portion  43  may form a step-like shape. 
     Note also that the contact  8  is not particularly limited to the mode of the above-described implementation example. For example, the contact  8  may have the same mode as the holding spring/contact  7  or may have other modes. 
     DESCRIPTION OF REFERENCE NUMERALS 
     
         
           1 : jack 
           2 : electronic device casing (set chassis) 
           3 : plug 
           4 : housing 
           41 : plug insertion portion 
           411 : halved portion 
           412 : holding hole portion 
           42 : low-height portion 
           43 : rear step portion 
           44 : sloping portion 
           5 : low-height contact 
           51 : fixed piece portion 
           511 : catching protrusion 
           52 : folded portion 
           521 : temporary fixation step portion 
           53 : elastic contact portion 
           54 : contact point 
           55 : connecting terminal portion 
           6 : low-height contact 
           7 : holding spring/contact 
           71 : fixed piece portion 
           72 : elastic contact portion 
           73 : connecting terminal portion 
           74 : contact point 
           8 : contact 
           9 : low-height contact accommodation portion 
           91 : main body accommodation hole 
           911 : press-fitting groove 
           92 : elastic contact portion accommodation hole 
           93 : temporary fixation pressure contact portion 
           94 : projection window 
           95 : preload portion 
           10 : low-height contact accommodation portion 
           101 : projection window 
           11 : holding spring/contact accommodation portion 
           111 : projection window 
           12 : contact accommodation portion