Electrical connector

[0002] The present invention relates to an electrical connector. More specifically, the present invention relates to a miniature electrical connector used for connecting electronic devices such as personal computers.

[0003] Recently, personal computers have begun to use miniature connectors referred to as USB (Universal Serial Bus) connectors.

[0004] Referring to FIG. 5, a miniature electrical connector, typically includes: a connector socket 2A mounted on a printed circuit substrate 1A. A connector plug 3A, is insertable within connector socket 2A. Connector socket 2A includes a shield case 4A, which is formed by bending a metal sheet in the shape of a rectangular column.

[0005] An insulative housing 6A, disposed within shield case 4A, supports four contact pins SA. Contact pins 5A are laterally arranged side-by-side. An intermediate section of contact pins 5A is fixed to an insulative housing base 6a. This arrangement connects external connecting ends 5ato contact pins 5A. An end support 6bis integrally molded with the upper half of insulative housing base 6a. End support 6bis formed so that its vertical thickness is roughly half that of shield case 4A. A bottom wall of end support 6b supports a contact end 5bof contact pins 5A.

[0006] Connector plug 3A connects to connector socket 2A. A shield case 7A, which is formed as a rectangular column, can be inserted inside shield case 4A. A space 8A is formed within a plug shield 7aof shield case 7A and receives end support 6b. A contactor 10 has a contact end 10apositioned directly below space 8A. Contact end 10ais supported by an end support 9aof an insulative housing 9A.

[0007] Shield cases 4A and 7A are formed by bending sheets of metal at right angles to form a rectangle. The bottom walls abut against each other to close the rectangle. However, due to “springing back” inherent in the bending) process, the left and right surfaces tend to open resulting in lowered production yields.

[0008] This springing back tendency is an obstacle to reducing the size of connector socket 2A and connector plug 3A. It is more difficult to process the shield cases 4A and 7A as their size is reduced.

[0009] An object of the present invention is to overcome the problems of the conventional miniature connector described above.

[0010] Another object of the present invention is to provide a structure that allows precise processing of shield cases into their requisite rectangular shapes.

[0011] Briefly stated, the present invention provides mutually engaging interlocking elements disposed on abutting left and right bottom walls of a shield case interlock to resist metal spring back. The shield cases arc formed by bending sheet metal into rectangular shaped columns. The shield cases surround the plug and socket in a miniature electrical connector. The socket has fixing wings and fixing legs which are soldered to a printed circuit board. The plug is removably inserted within the socket.

[0012] According to an embodiment of the invention, there is provided an electrical connector comprising: a shield case; the shield case being a sheet metal; a first end of the sheet metal being bent to form a first portion of a bottom wall; at least a first interlocking element disposed on an end of the first portion; a second end of the sheet metal being bent to form a second portion of the bottom wall; at least a second interlocking element disposed on an end of the second portion; and the first and second portions being bent to interengage whereby the first and second interlocking elements interlock to prevent the bottom wall from opening due to spring back.

[0013] According to another embodiment of the invention, there is provided an electrical connector comprising: a plug shield case; the plug shield case being a sheet metal; a first end of the sheet metal being bent to form a first portion of a bottom wall; at least a first interlocking element disposed on an end of the first portion; a second end of the sheet metal being bent to form a second portion of the bottom wall; at least a second interlocking element disposed on an end of the second portion; and the first and second portions being bent to interengage whereby the first and second interlocking elements interlock to prevent the bottom wall from opening due to spring back.

[0014] According to yet another embodiment of the invention, there is provided an electrical connector comprising: a shield case; the shield case being a sheet metal; a first end of the sheet metal being bent to form a first portion of a bottom wall; at least a first interlocking element disposed on an end of the first portion; a second end of the sheet metal being bent to form a second portion of the bottom wall; at least a second interlocking element disposed on an end of the second portion; the first and second portions being bent to interengage whereby the first and second interlocking elements interlock to prevent the bottom wall from opening due to spring back; a plug shield case; the plug shield case being a sheet metal; a first end of the sheet metal being bent to form a first portion of a bottom wall; at least a first interlocking element disposed on an end of the first portion; a second end of the sheet metal being bent to form a second portion of the bottom wall; at least a second interlocking element disposed on an end of the second portion; the first and second portions being bent to interengage whereby the first and second interlocking elements interlock to prevent the bottom wall from opening due to spring back; and the plug shield case being removably fittable within the shield case.

[0015] The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.

[0016] FIG. 1 is an exploded perspective drawing of an electrical connector according to the present invention with a section cut away.

[0017] FIG. 2 is a longitudinal cross-section drawing of the miniature connector.

[0018] FIG. 3 is a cross-section detail drawing along the 3—3 line of the miniature connector in FIG. 2.

[0019] FIG. 4 is a bottom-view detail drawing of a connector socket from the miniature connector.

[0020] FIG. 5 is a side-view detail drawing of a conventional USB connector with one section cut away.

[0021] Referring to FIGS. 1 and 2, a miniature electrical connector includes a connector socket 2. Connector socket 2 is mounted on a surface of a printed circuit substrate 1. A connector plug 3 has a plug 3athat can be inserted into an insertion opening 21 of connector socket 2.

[0022] Connector socket 2 includes a shield case 4. Shield case 4 is formed by bending a sheet of metal into a rectangular cylinder so that an end defines insertion opening 21.

[0023] Referring now to FIGS. 1 and 3, a pair of fixing wings 4care formed at the bottom edges of a left side wall 4aand right side wall 4bof shield case 4, respectively. Each Fixing wing 4cis bent to form an L-shaped structure with the foot of L-shaped fixing wing 4cfacing printed circuit substrate 1. A pair of fixing legs 4dare formed by cutting rear sections of shield case 4 so that a left and right leg 4dprojects downward towards printed circuit substrate 1.

[0024] Referring to FIG. 3, the bottom wall of shield case 4 is separated from the surface of printed circuit substrate 1 by a gap L1. Fixing wings 4cand fixing legs 4dextend past a bottom wall 4cof shield case 4 and rest on the surface of printed circuit substrate 1 ensuring that gap Ll is maintained. In this way, when connector socket 2 is mounted on printed circuit substrate 1, bottom wall 4eis prevented from making contact with printed circuit substrate 1. Only the bottom surfaces of fixing wings 4cand fixing legs 4dare in contact with the conductor layer of printed circuit substrate 1. Fixing wings 4cand fixing legs 4dare fixed to printed circuit substrate 1 using solder dipping. This ensures that connector socket 2 is firmly attached to printed circuit substrate 1. Thus, the flux from the soldering operation can be easily let out through gap L1 formed between printed circuit substrate 1 and bottom wall 4e.

[0025] Referring to FIG. 4, bottom wall 4eof shield case 4 is formed by perpendicularly bending left and right side walls 4aand 4brespectively, until their end surfaces abut each other. Two mutually engaging interlocking claw-shaped elements 4fand 4gare disposed along the ends of left and right side walls 4aand 4b. Interlocking elements 4fand 4ginterlock with each other aligning and holding shield case 4 firmly in shape against the tendency of the material to spring back after bending.

[0026] Two bridge projections, 4hand 4i, are formed along bottom wall 4e. Bridge projections 4hand 4iproject downward toward printed circuit substrate 1. Bridge projections 4hand 4iprevent bottom wall 4efrom opening even when stressed due to improper insertion or removal of connector plug 3.

[0027] Referring again to FIGS. 1 and 2, an insulative housing 6, molded from resin, is positioned inside shield case 4. Insulative housing 6 supports four contact pins 5. Contact pins 5 are arranged in a row along the lateral axis of shield case 4.

[0028] Insulative housing 6 fits within shield case 4. In order to facilitate and ensure precise positioning of insulative housing 6, shield case 4 has two slots 22. Slots 22 are formed along a rear portion left wall 4aand right wall 4b. Ridge projections 6eare integrally formed in insulative housing 6. Projections 6efit within slots 22. This arrangement guides insulative housing 6 as it is inserted within shield case 4. Because of the interlocking nature of slots 22 and projections 6e, insulative housing 6 is aligned and stabilized when inserted into shield case 4.

[0029] Insulative housing 6 is inserted into shield case 4 from the rear. Ridge projections 6eof insulative housing 6 fit into slots 22. This arrangement vertically stabilizes insulative housing 6 relative to shield case 4. Also, housing 6 is prevented from moving, forward relative to shield case 4, thereby securing the forward positioning of insulative housing 6.

[0030] Insulative housing 6 includes a base 6a. Base 6ahas a cross-sectional dimension that is roughly the same as the cross-sectional dimension of the inside of shield case 4. Two cavities (not shown) are formed on an upper surface of base 6a. Two fixing claws 4kare formed by cutting and bending an upper wall 4jof shield case 4. Fixing claws 4kfit into the two cavities (not shown.) Thus, when insulative housing 6 is inserted into shield case 4 during assembly, fixing claws 4kare inserted into the corresponding cavities. This positions insulative housing 6 relative to shield case 4 and fixes same.

[0031] An end support 6cis formed integrally with base 6aas a cantilevered projection within shield case 4. Four attachment (grooves 23 are formed along the length of end support 6cand base 6a. Attachment grooves 23 are arranged parallel to each other along the lateral axis of shield case 4. Elastic metal contact pins 5 are positioned in each attachment groove 23. An intermediate section of contact pins 5 is fixed within corresponding attachment grooves 23. External connection ends 5a, formed as L-shaped bends in contact pins 5, extend out from the rear of shield case 4. External connection ends 5aare soldered to the conductor layer of printed circuit substrate 1.

[0032] Contact ends 5bare formed as arcuate bends in contact pins 5. Contact ends 5bare exposed upwardly from within attachment grooves 23 to an upper surface of end support 6c. Contact ends 5bare held by engagement pieces 6d. Engagement pieces 6dare formed integrally with an end of end support 6c. Engagement pieces 6dprevent external connection ends 5afrom freely projecting outside corresponding attachment grooves 23.

[0033] Referring to FIGS. 2 and 3, connector plug 3 is covered with an outer insulative resin covering. Plug 3aand a shield case 7 are also covered with an insulative resin. Plug 3aincludes a plug shield 7a. Plug shield 7ahas an outer dimension that corresponds to the inner dimension of shield case 4. Plug 3afits within insertion opening 21. As with shield case 4 described above, plug shield 7ais formed by bending a sheet of metal into a rectangular column. All end support 9aof an insulative housing 9 is positioned inside plug shield 7a. End support 9asupports four contactors 10. Contactors 10 and contact pins 5 are aligned with each other.

[0034] Contact ends 10aof contactors 10 are exposed at a bottom wall of end support 9a. Contact ends 10aextend along an upper wall of plug shield 7a. A space 24 is bounded by end support 9aand plug shield 7a. Space 24 receives end support 6cof insulative housing 6 described above. Thus, when plug 3aof connector plug 3 is fitted into insertion opening 21, end support 6cand end support 9aare brought close together. End support 6cis positioned just below end support 9afacing each other. As a result, contact ends 10aof contactors 10 come into contact with corresponding contact ends 5bof contact pins 5.

[0035] Shield case 7, described above, includes a cord shield 7b. Cord shield 7bis formed integrally with plug shield 7a. Cord shield 7bis formed to enclose a comparatively large volume. A cord connector 9b, which is connected to end support 9a, is positioned inside cord shield 7b. Cord connection ends 10bof contactors 10 are positioned within cord connector 9b. Cord connection ends 10bare fixed via solder to wires 25ain a connection cord 25. Connection cord 25 feeds in from an end of cord shield 7b.

[0036] Referring again to FIGS. 1 and 2, assembled connector socket 2 is mounted on the surface of printed circuit substrate 1. Shield case 4 is formed using a sheet metal blank. The sheet metal blank is bent at right angles. However, due to the spring-back effect of metal inherent in the bending process, a bottom wall 4eof shield case 4 will tend to open outward when the two ends are abutted against each other. This is why the abutting surfaces of bottom wall 4eof shield case 4 are formed with mutually engaging claw elements 4fand 4g. Claw elements 4fand 4gengage each other and reliably prevent bottom wall 4efrom opening.

[0037] A bottom wall 7cis formed with claw elements 7danalogous with claw elements 4fand 4g(FIG. 4) described above. This prevents the abutting left and right bottom walls 7cfrom opening.

[0038] As insulative housing 6, to which contact pins 5 are attached, is inserted into shield case 4, it is guided and supported by ridge projections 6e. Insulative housing 6 is firmly fixed to shield case 4 due to the interaction of slots 22 with ridge projections 6e. Fixing claws 4kengage insulative housing 6 and prevent insulative housing 6 from disengaging from shield case 4.

[0039] Connector socket 2 is soldered to printed circuit substrate 1 using solder dipping. Fixing) wings 4cand fixing legs 4dof shield case 4 are soldered to the conductor layer of printed circuit substrate 1. Thus, even if a large external force is applied to connector socket 2 during insertion or removal of connector plug 3, connector socket 2 remains firmly fixed to printed circuit substrate 1. Fixing legs 4dfirmly hold external connection ends 5aof contact pins 5 against the conductor layer of printed circuit substrate 1.

[0040] If shield case 4 is “forced” by an external force during insertion or removal of connector plug 3, bottom wall 4eof shield case 4 will tend to open. If this happens, the bottom surfaces of projections 4hand 4iwill come into contact with the surface of printed circuit substrate 1. Once this happens, any further opening is prevented. This prevents bottom wall 4efrom being forced open and coming into contact with the conductor layer of printed circuit substrate 1.

[0041] As the description above makes clear, interlocking claw-shaped elements 4f, 4gand 7ddisposed on bottom walls 4eand 7crespectively, allow bottom walls 4eand 7cto be precisely aligned while minimizing spring back. The resulting connector can be made very small.

[0042] Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.