Patent Publication Number: US-7585189-B2

Title: Electrical connector

Description:
FIELD OF THE INVENTION 
     The present invention relates to connector technique in electronic or communication field, especially to a connector plug. 
     BACKGROUND OF THE INVENTION 
     In an existing data communication system, user terminals usually perform data communication with line equipment in the nearest exchange office through subscriber line and signal line, and the connector connected with data cable or communication cable serves as the interface of the subscriber line and the interface of the signal line to achieve signal transmission. 
     For an Asymmetric Digital Subscriber Line (ADSL), for example, the access equipment usually comprises two parts: Digital Subscriber Line Amplitude Module (DSLAM) and Remote Transceiver Unit (RTU) at subscriber side. As the equipment at office end, DSLAM performs functions of ADSL, such as transmitting/receiving, encoding/decoding, bandwidth multiplexing, and system maintenance and management, etc.; as the equipment at remote end, RTU provides an access port, including ordinary telephone interface, to the subscriber. On the equipment at office end, a connector interface is used to provide subscriber line interface to implement connection between the subscriber line and the equipment at office end. 
     An existing connector commonly used as a connector for subscriber line interface are a double-edged connector with a spacing of 2.17 mm, comprising a connector plug and a connector socket.  FIG. 1  is an end view of a connector plug  10 , which comprises metal interface portion  11 , insulator  12  provided in said interface portion  11 , contacts  13  evenly distributed on both sides of said insulator  12 , plastic enclosure  14  connecting data cable and metal interface portion  11 , and fixing screws  15  for connectively fixing the entire plug to a socket. 
     The profile of said metal interface portion  11  is in isosceles trapezoid shape, with the four corners of the trapezoid-shaped shell being rounded, like a inverted letter “D”; the trapezoid-shaped shell matches a female socket  30  (as shown in  FIG. 2 ) to prevent misplugging. Said plastic insulator  12  appears as a band-shaped protrusion at the center inside of said interface portion  11 , with slots that can accommodate said contacts  13  provided on both sides thereof. Said contacts  13  are provided in said slots, with a spacing of 2.16 mm between two adjacent contacts. In a connector with 64 contacts, for example, the connector is 98.43 mm (L)*15.37 mm (W), and the footprint of each pair of contacts is 47.28 mm 2 . A connector with a plug of such structure is large in entire volume, with large footprint of interface and low pin density of the contacts. 
     In addition, said data cable is electrically connected with said contacts  13  by passing through said plastic enclosure  14 ; the connection is usually achieved through press fit, i.e., there is a knife-edge provided at the end of the contact near the cable, and when assembling, the cable is pressed into the knife-edge with a tool, so that the electrical connection between the cable and the contact is achieved. However, if the cable and the contact are connected by such a press fit method, the contact is often caused to be warped, thereby affecting contact reliability. Meanwhile, connection between the contact and the cable can not be achieved by welding, thereby limiting the use of the connector. 
     SUMMARY OF THE PRESENT INVENTION 
     An embodiment of the present invention provides a connector plug with small interface footprint and high pin density. 
     A further embodiment of the present invention provides a connector plug that can be connected with the cable by welding and make the cable welding visible. 
     According to an embodiment of the present invention, a high density connector plug comprises the body of plug and a plastic enclosure for fixing said body of plug and being connected with the cable; said body of plug comprising a shielding shell, an insulator mounted in said shielding shell, and a set of contacts provided on the side of said insulator; said insulator comprising a base and upper plastic body and lower plastic body extending outwards from one side of said base; slots for mounting said contacts being provided on the upper and lower surfaces of said upper plastic body and lower plastic body respectively. 
     Said insulator of said high density connector plug also comprises a stepped welding area extending outwards from the other side of said base; there are mounting grooves communicating with the slots at said upper plastic body and lower plastic body provided on the surface of said welding area. 
     Said welding area of said high density connector plug has a first plastic body extending outwards from said base and a second plastic body extending outwards from said first plastic body, provided in a stepped-shape; said mounting grooves comprise a plurality of first mounting grooves provided on the upper surface of said first plastic body and communicating with the slots at the upper surface of said upper plastic body, a plurality of second mounting grooves provided on the upper surface of said second plastic body and communicating with the slots at the lower surface of said upper plastic body, a plurality of third mounting grooves provided on the lower surface of said second plastic body and communicating with the slots at the upper surface of said lower plastic body, and a plurality of fourth mounting grooves provided on the lower surface of said first plastic body and communicating with the slots at the lower surface of said lower plastic body; there are insulating spacers provided between said mounting grooves, respectively. 
     Said set of contacts of said high density connector plug comprise a plurality of short contacts mounted in said first mounting grooves and fourth mounting grooves, as well as a plurality of long contacts mounted in said second mounting grooves and third mounting grooves. 
     Said short contact of said high density connector plug comprises front contact portion provided in a slot at the upper surface of said upper plastic body or the lower surface of said lower plastic body, middle portion passing through the base of said insulator, welding portion provided in a mounting groove at said welding area, and flanged edge extending upwards from a side of said welding portion and higher than said insulating spacer; the flanged edges of said plurality of short contacts mounted in said first mounting grooves are arranged in the same orientation; the flanged edges of said plurality of short contacts mounted in said fourth mounting grooves are arranged in the same orientation. 
     The contact portion of said short contact in said high density connector plug has a guide chamfer at its front end. 
     Said long contact of said high density connector plug comprises front contact portion provided in a slot at the lower surface of said upper plastic body or the upper surface of said lower plastic body, middle portion passing through the base of said insulator, welding portion provided in a mounting groove at said welding area, and flanged edge extending upwards from a side of said welding portion; the flanged edges of said plurality of long contacts mounted in said second mounting grooves are arranged in the same orientation; the flanged edges of said plurality of long contacts mounted in said third mounting grooves are arranged in the same orientation. 
     The contact portion of said long contact in said high density connector plug has a guide chamfer at its front end. 
     Said upper plastic body of said high density connector plug is shorter than said lower plastic body; and, said upper and lower plastic bodies are in symmetry with reference to the center line, respectively. 
     Said shielding shell of said high density connector plug comprises a rear metal shell mounted in said plastic enclosure and a front metal shell provided at the front end of said plastic enclosure; said front metal shell has a round protrusion provided on its inner wall. 
     Compared to the prior art, there are upper and lower plastic bodies provided on the insulator of the high density connector plug according to the present invention, so that the footprint of the interfacing portion of plug and socket is reduced and the pin density is increased; therefore, the volume of the corresponding device is reduced significantly, so that the device can have a trend towards miniature and high density. In addition, there is a stepped welding area provided on the insulator, so that the contacts can be connected with the cable by welding, and the cable welding is visible, thereby the working efficiency is improved; the design of long and short contacts can facilitate assembling in the insulator; the flanged edge design of the welding area of the contacts and the cable, in conjunction with the pull-welding processing method that can accomplish the welding with a single action, is advantageous to improve welding efficiency and prevent the solder from flowing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an end view of the plug of a double-edged connector in the prior art; 
         FIG. 2  is an end view of the socket in a double-edged connector in the prior art; 
         FIG. 3  is a stereogram of the plug and the socket in a high density connector according to an embodiment of the present invention; 
         FIG. 4  is an exploded view of the high density connector plug according to an embodiment of the present invention; 
         FIG. 5  is an end view of the front metal shell of the shielding shell of the high density connector plug according to an embodiment of the present invention; 
         FIG. 6  is an end view of the rear metal shell of the shielding shell of the high density connector plug according to an embodiment of the present invention; 
         FIG. 7  is a stereogram of the insulator of the high density connector plug according to an embodiment of the present invention; 
         FIG. 8  is a front view of the insulator of the high density connector plug according to an embodiment of the present invention; 
         FIG. 9  is a sectional view of the insulator of the high density connector plug according to an embodiment of the present invention; 
         FIG. 10  is a stereogram of the long contacts of the high density connector plug according to an embodiment of the present invention; 
         FIG. 11  is a stereogram of the short contacts of the high density connector plug according to an embodiment of the present invention; 
         FIG. 12  is a schematic diagram of assembling of the short contacts with the insulator in the high density connector plug according to an embodiment of the present invention; 
         FIG. 13  is a schematic diagram of assembling of the long contacts with the insulator in the high density connector plug according to an embodiment of the present invention; 
         FIG. 14  is a schematic diagram of assembling of the insulator and the shielding shell in the high density connector plug according to an embodiment of the present invention; 
         FIG. 15  is a stereogram of the assembled high density connector plug according to an embodiment of the present invention; 
         FIG. 16  is a rear view of the assembled high density connector plug according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Hereunder a high density connector plug according to an embodiment of the present invention is further described in detail, with reference to the attached drawings. 
     As shown in  FIG. 3 , the connector comprises connector plug  20  and connector socket  40 . The connector plug  20  can be used to connect with data cable  60  with multiple twisted pairs; and the connector socket  40  can be used to connect with a PCB (not shown). Both the connector plug  20  and the connector socket  40  are completely shielded at the interfacing portion; wherein, the connector plug  20  is shielded by the shielding shell  21  of the plug, and the connector socket  40  is shielded by the metal shell  41  of the socket. The connector plug  20  and the connector socket  40  match with each other in interface; when the connector plug  20  and the connector socket  40  are coupled with each other, the front metal shell  211  (referring to  FIG. 4 ) of the shielding shell  21  of the plug  20  and the metal shell  41  of the socket  40  are connected with each other, thereby achieving complete shielding at the interfacing portion. 
     The connector plug  20  further comprises two fixing screws  22  used to fix the connector plug  20  to the socket  40 , and the connector socket  40  further comprises two fixing nuts  42  for fixing the connector plug  20 . When the screws  22  on the connector plug  20  are connected completely with the fixing nuts  42  on the connector socket  40 , the connector plug  20  contacts completely with the connector socket  40 , so as to achieve connection of electrical signal. 
     As shown in  FIG. 3  and  FIG. 4 , the high density connector plug  20  according to an embodiment of the present invention comprises the body of plug and a plastic enclosure  23  that is used to fix said body of plug and connect the cable. Said body of plug comprises shielding shell  21 , insulator  24  mounted in said shielding shell  21 , and a set of contacts provided on the side of said insulator  24 . Said shielding shell  21  comprises front metal shell  211  and rear metal shell  212 . Said front metal shell  211  matches with the metal shell  41  of the socket  40 ; said rear metal shell  212  is fixedly connected with the plastic enclosure  23 , so that the entire body of plug is fixed on the plastic enclosure  23 . Said set of contacts comprises a plurality of long contacts  25  and a plurality of short contacts  26 ; in this embodiment, there are 64 contacts (only 16 are shown in the figure; of course, an appropriate number of contacts may be designed as required). 
     As shown in  FIG. 5 , said front metal shell  211  is punched out on the metal shell base  110  and comprises two parts: a generally rectangular shielding shell  111  for plug interface, with four metal walls, two longitudinal sidewalls  112  and two lateral sidewalls  113 , wherein the longitudinal sidewall  112  transits to the lateral sidewall  113  via a large round corner  114  or a small round corner  115 ; the radius of the large round corner  114  is different from that of the small round corner  115 , so as to implement asymmetry of the shielding shell of the interface, in order to prevent misplugging when the connectors are coupled with each other; and some small round protrusions  116  may be provided at the inner wall of the longitudinal side wall  112 , to ensure a certain retention force when the shielding shell of the plug interface and the shielding shell of the socket interface are coupled with each other; and two fixing screw holes  117 , at both sides of the rectangular diagonal line of the shielding shell  111  of plug interface, and in the same size larger than the diameter of the fixing screws  22 , for passing through the fixing screws  22 . 
     As shown in  FIG. 6 , said rear metal shell is punched out on the rear metal shell base  120  and comprises two parts: a rectangular shielding shell  121  for plug interface, with four metal walls, two longitudinal sidewalls  122  and two lateral sidewalls  123 , wherein the longitudinal sidewall  122  transits to the lateral sidewall  123  via a round corner; and the rectangle matches the rear half part of the plastic insulator  24  of the plug in size, forming a rear metal shielding; and fixing screw holes  124 , at both sides of the rectangular diagonal line of the shielding shell of plug interface, and in the same size larger than the diameter of the fixing screws, for passing through the fixing screws. 
     As shown in  FIG. 7  and  FIG. 8 , said insulator  24  comprises a base  241 , an upper plastic body  242  and a lower plastic body  243  extending outwards from one side of said base  241 ; there are slots  244  for mounting said contacts provided on the upper and lower surfaces of said upper plastic body  242  and lower plastic body  243 . Said upper plastic body  242  is different from said lower plastic body  243  in length, but they are symmetric with reference to the center line thereof, respectively, in order to achieve the function of preventing misplugging; of course, said upper and lower plastic bodies can be in an asymmetric structure to prevent misplugging. There are 16 slots  244  of the same size distributed on each side of the upper plastic body  242 , respectively, for mounting the contacts; also, there are 16 slots of the same size distributed on each side of the lower plastic body  243 , respectively, for mounting the contacts; said base  241  is in a rectangular shape, with the four corners chamfered into round corners of different radius, in order to match the front metal shell  211  (as in  FIG. 5 ) of the connector plug; and position data  245  for the metal contacts is labeled on said base  241 , for reference during mounting. 
     Said base  241  is in the stepped welding area extending outwards from the other side of said upper plastic body  242  and lower plastic body  243 ; there are mounting grooves provided on the surface of said welding area, communicating with the slots  244  at said upper plastic body  242  and lower plastic body  243 . Said welding area comprises the first plastic body  246  extending outwards from said base  241  and the second plastic body  247  extending outwards from said first plastic body  246 , provided in a stepped shape. As shown in  FIG. 9 , said mounting grooves comprise a plurality of first mounting grooves  461  provided on the upper surface of said first plastic body  246  and communicating with the slots  244  at the upper surface of said upper plastic body  242 , a plurality of second mounting grooves  462  provided on the upper surface of said second plastic body  247  and communicating with the slots  244  at the lower surface of said upper plastic body  242 , a plurality of third mounting grooves  463  provided on the lower surface of said second plastic body  247  and communicating with the slots  244  at the upper surface of said lower plastic body  243 , and a plurality of fourth mounting grooves  464  provided on the lower surface of said first plastic body  246  and communicating with the slots  244  at the lower surface of said lower plastic body  243 ; there are insulating spacers  465  provided between said mounting grooves, respectively. 
     As shown in  FIG. 10 , said long contact  25  comprises front contact portion  251  provided in a slot  244  at the lower surface of the upper plastic body  242  or the upper surface of the lower plastic body  243 , middle portion  252  passing through the base of said insulator  24 , welding portion  253  provided in a mounting grooves at said welding area, and flanged edge  254  extending upwards from a side of said welding portion  253 . There is a guide chamfer  255  provided at the front end of the contact portion  251 , designed to provide guide function when plug  20  is connected with socket  40 , to facilitate fitting of plug  20  and socket  40 . Said front contact portion  251  is designed to connect with the contact portion of socket  40 , forming reliable electrical connection; the middle portion  252  of said contact is designed to match a slot on the plastic insulator  24  of the plug, in order to hold the contact in the insulator  24  stably; said welding portion  253  is designed to match the cable  60 , the cable  60  being fixable to the contact by welding to establish electrical connection; said flanged edge  254  is higher than the insulating spacer  465  between the grooves for fixing metal contact in the insulator  24  (as shown in  FIG. 16 ), for effectively blocking the solder from flowing across separate contacts during the pull-welding process. 
     As shown in  FIG. 11 , said short contact  26  is substantially in the same structure as said long contact and comprises front contact portion  261  in a slot  244  provided on the lower surface of the upper plastic body  242  or the upper surface of the lower plastic body  243 , middle portion  262  passing through the base  241  of said insulator  24 , welding portion  263  provided in a mounting groove at said welding area, and flanged edge  264  extending upwards from a side of said welding portion  263  and higher than said insulating spacer  465 . And, there is a guide chamfer  265  provided at the front end of said contact portion  261 . Compared to said long contact, the short contact is different in length of the middle portion, orientation of the chamfer, and slot for mounting. 
     When the high density connector plug according to an embodiment of the present invention is assembled, first, as shown in  FIG. 12 , 16 short contacts  26  are arranged together according to the spacing between the first mounting grooves  461  in the welding area with a clamp, with the flanged edges  264  of the contacts arranged in the same orientation; then, the short contacts are pressed into said first mounting grooves  461  with an appropriate press-fit tool and reach the slots  244  at the upper surface of said upper plastic body  242  so as to be fixed. 
     Next, as shown in  FIG. 13 , 16 long contacts  25  are arranged together according to the spacing between the second mounting grooves  462  in the welding area, with the flanged edges  254  of the contacts arranged in the same orientation; then, the long contacts  25  are pressed into said second mounting grooves  462  with an appropriate press-fit tool and reach the slots  244  at the lower surface of said upper plastic body  243  so as to be fixed. 
     Next, as shown in  FIG. 12  again, 16 short contacts  26  are arranged together according to the spacing between the fourth mounting grooves  464  in the welding area, with the flanged edges  264  of the contacts arranged in the same orientation; then, the short contacts  26  are pressed into said fourth mounting grooves  464  with an appropriate press-fit tool and reach the slots  244  at the lower surface of said lower plastic body  243  so as to be fixed. 
     Next, as shown in  FIG. 13  again, 16 long contacts  25  are arranged together according to the spacing between the third mounting grooves  463  in the welding area, with the flanged edges  254  of the contacts arranged in the same orientation; then, the long contacts  25  are pressed into said third mounting grooves  463  with an appropriate press-fit tool and reach the slots at the upper surface of said lower plastic body  243 . 
     Next, as shown in  FIG. 14 , the front metal shell  211 , the insulator  24  with 64 contacts  25  and  26 , and the rear metal shell  212  are assembled together, and then the screw holes in both of the metal shells are riveted together, to complete the assembling of the connector plug; the assembled connector plug is shown in  FIGS. 15 and 16 . 
     Through providing the upper plastic body and the lower plastic body on the insulator for mounting contacts, the present invention reduces the spacing therebetween with a little increase in width, resulting in reduced footprint of connector interface and increased pin density. In a 64-Pin connector, for example, with the same number of contacts, the interface footprint is reduced from 512.9 mm 2  (98.43 mm×15.37 mm) to 554.8 mm 2  (38 mm×14.6 mm), i.e., reduced to about ⅓. Meanwhile, the pin density of the contacts is increased from 47.28 mm 2 /2 Pins to 16.27 mm 2 /2 Pins, i.e. increased to almost 3 times. Reduced interface footprint and increased pin density reduce the volume of the corresponding device, so that the devices have a trend towards miniature and high density. 
     In addition, there is a stepped welding area on the insulator, so that the contacts can be connected to the cable by welding, and, in conjunction with the pull-welding processing method, quick manual welding of multi-core cable is achieved; and the cable welding is made visible, thereby the working efficiency can be improved; the design of long and short contacts facilitates quick assembling in the insulator; the flanged edge design of the contacts and the welding area, in conjunction with the pull-welding process, is advantageous to improve welding efficiency and prevent the solder from flowing; and since the flanged edges of the contacts are arranged in the same orientation, the insulating clearance between contacts is increased effectively, and thereby the insulating strength of the connector is increased.