Electrical connector

Abstract: An electrical connector includes a receptacle connector (1) comprising an insulating housing (3) containing a plurality of contacts (4) and a shielding shell (20) disposed so as to enclose the contact portions (41) of the contacts (40) and a plug connector (2) including a second insulating housing containing a plurality of contacts and a second shielding shell (60) disposed so as to enclose contact portions of the second contacts. A mounting frame (10) for mounting the shielding shell (20) on an object defines with the shielding shell (20) a circumferential channel (12) into which a front end of the second shielding shell (60) is to be fitted. The insulating housing (30) has a front contact enclosure (31) to enclose the contact portions (41) of the contacts (40) and the shielding shell (20) has a front enclosure (21) into which the front contact enclosure (31) is fitted. The mounting frame (10) has a central opening (12) for receiving the front enclosure (21) and a stepped edge (12') around the central opening so as to define with the shielding shell (20) the circumferential channel (12) into which the front end of the second shielding shell (60) is to be fitted to make electrical connections between the shielding shells (20,60).

Description: The present invention relates generally to electrical connectors for printed circuit board (PCB) and, more particularly, to an electrical connector including an insulating housing containing a plurality of substantially L-shaped contacts, front portions of which are adapted to engage mating contacts and rear portions of which extend downwardly through the insulating housing. This application has been divided out of European patent application 0292144. A variety of electrical connectors suitable for mounting on an equipment panel or PCB are well known. For example, it is known that the rear portions of contacts such as described above are bent so that their axes become substantially perpendicular to a plane of the PCB, and the rear ends are inserted into plated-through-holes (PTH) of the PCB to mount the receptacle connector in such a manner that the mating plug connector may be fitted into the receptacle connector in a plane parallel to the plane of the PCB. The above PCB electrical receptacle connector has been assembled by bending contacts by 90 degrees either after insertion into the insulating housing or before inserting the bent contacts into the insulating housing. For this reason, an upper rear portion of the insulating housing has been cut off to handle the bent portions of the contacts. As a result, the bent portions are exposed at the cut-off portion, presenting the following problems. (1) Since the bent portions are exposed from the insulating housing of a receptacle connector mounted on a unit or the like, dust or dirt tends to adhere to the contacts, causing poor insulation or even short circuiting across the contacts. (2) The exposed contact portions are very easy to accidentally contact by the installing or maintenance personnel, creating a hazardous condition. (3) The exposed contact portions impair the electromagnetic interference (EMI) shielding action of the receptacle connector. (4) When the PCB becomes faulty, the entire electrical connector must be replaced by removing all the mounting screws. This is a very time consuming and troublesome operation when a large number of such electrical connectors are mounted on the panel. Recently, there is the increasing use of electrical connectors with a shielding shell for enclosing the contact containing insulating housing to prevent not only electromagnetic interference (EMI) but also damage to the electrical connector caused by plugging or unplugging operations or cable load itself. As the size and weight of electronic equipment decrease, there is an increasing demand for a compact and light electrical connector to be mounted on a PCB. In general, the contact portions of contacts mounted in the electrical connector may be made compact by reducing the current capacity so that it is relatively easy to reduce the size of the entire contact. In the above electrical connector, however, the shielding shells of both receptacle and plug connectors must be engaged with each other so that there is the minimum shield length for effective engagement, thus limiting reduction in the connector length. Accordingly, the present invention seeks to provide a printed circuit board, electrical receptacle connector which is free from the above problem. The invention further seeks to provide a compact electrical connector. According to the invention there is provided an electrical connector comprising: a receptacle connector including a first insulating housing containing a plurality of first contacts and a first shielding shell disposed so as to enclose contact portions of said first contacts; a plug connector including a second insulating housing containing a plurality of second contacts and a second shielding shell disposed so as to enclose contact portions of said second contacts; mounting means for mounting said first shielding shell on an object and defining with said first shielding shell a circumferential channel into which a front end of said second shielding shell is to be fitted; said first insulating housing having a front contact enclosure to enclose said contact portions of said contacts; said first shielding shell having a front enclosure into which said front contact enclosure is fitted; and said mounting means having a central opening for receiving said front enclosure and a stepped edge around said central opening so as to define with said first shielding shell said circumferential channel into which said front end of said second shielding shell is to be fitted to make electrical connections between said first and second shielding shells. In order that the invention may be better understood, several embodiments thereof will now be described, by way of example only, and with reference to the accompanying drawings in which:- Figure 1 is an exploded perspective view of an electrical receptacle connector with an electrical plug connector according to an embodiment of the invention; Figure 2 is a sectional view of the plug connector plugged into the receptacle connector of Figure 1 which is mounted on a printed circuit board; Figure 3 is an exploded perspective view of an electrical receptacle connector according to another embodiment of the invention; and Figure 4 is a sectional view of the receptacle connector of Figure 3 mounted on a printed circuit board. In Figure 1 there is shown a receptacle connector 1 adapted to mount on a PCB. The receptacle connector 1 includes a mounting frame 10 with generally L-shaped side profiles, a shielding shell 20 to be fitted into the mounting frame 10 to form a shielding housing, and an insulating housing 30 for holding a plurality of female contacts 40 in place. The mounting frame 10, a part of the receptacle connector for receiving a mating plug connector 2, is preferably made of metal by die casting so as to have a generally rectangular front flange 11. The front flange 11 has a central mount opening 12 of an inverted substantially trapezoidal shape. The mount opening 12 is provided with an stepped edge 12'. A pair of latch arms 13 extend forwardly from the front flange 11 on opposite sides of the mount opening 12 for engagement with a pair of latch devices 80 of a mating plug connector 2. A pair of threaded holes 14 are provided on opposite sides of the front flange 11 for mount on a panel of a unit or the like with bolts or screws. A pair of mounting legs 15 extend rearwardly from the back of the front flange 11 on opposite sides. Each mounting leg 15 has a vertical wall 15A and a horizontal wall 15B. The vertical wall 15A is adapted to engage a latch device 33 of the insulating housing 30 for integration. That is to say, the vertical wall 15A has a tapered rear portion 15A-2 and a latch recess 15A-1 adapted to engage a latch boss 33-2 of the latch device 33 to lock the insulating housing 30 to the mounting frame 10. It also has a guide rim 15A-3 on the inside for fitting into a guide groove 33-4 of the latch device 33. The horizontal wall 15B has a threaded hole 15B-1 into which a bolt or screw is threaded to mount the receptacle connector 1 on a PCB. It is also possible to ground the mounting frame 10 to a ground conductor of the PCB through the bolt or screw. The shielding shell 20 is formed from sheet metal so as to have a front enclosure 21 for enclosing a front contact enclosure 31 of the insulating housing 30. The front enclosure 21 has a plug receptacle 22 through which a front end of the insulating housing 30 is accessible. A rear flat cover 23 extends rearwardly from an upper rear end of the shielding shell 20 to cover the L-shaped rear portions 42 of female contacts 40 which are exposed from the insulating housing 30. A plurality of resilient bosses 24 are provided on the top of the shielding shell 20 to eliminate any play when the shielding shell 20 is inserted into the mount opening 12 of the mounting frame 10. These resilient bosses 24 also serve to electrically connect the mounting frame 10 and the shielding shell 20. A stopper jaw 25 is provided at the lower rear end of the front enclosure 21 to abut the back of the front flange 11 of the mounting frame 10 to stop further advancement of the shielding shell into the mount opening 12 of the mounting frame 10 beyond a certain point and electrically connect the shielding shell 20 to the mounting frame 10. A pair of latch apertures 26 are provided on the top of the shielding shell behind the resilient bases 24 to receive a pair of latch bosses 35 for locking the shielding shell 20 and the insulating housing 30. The insulating housing 30 may be integrally made of an insulating material such as a plastic so as to have a front contact enclosure 31 with a contact receptacle 32 for receiving the plug connector 2. The front contact enclosure 31 encloses the contact portions 41 of contacts 40. A pair of latch devices 33 are provided on opposite sides of the insulating housing 30. The insulating housing 30 has a rear base plate 34 at its lower rear end. As best shown in Figure 2, a plurality of contact receiving apertures 34' are provided on the rear base plate 34 in the same pattern as that of PTHs of a PCB 95. The rear ends 42 of female contacts 40 extend downwardly and pass through these apertures 34'. The free ends of the contacts 40 projecting from the rear base plate 34 are inserted into respective PTHs of the PCB when the receptacle connector 1 is mounted on the PCB 95. A latch lever 33-1 is cantilevered on top of the latch device 33 with a slot 33-3. The latch lever 33-1 has a tapered latch boss 33-2 on its outside. A guide groove 33-4 is provided on the outside below the latch lever 33-1 to receive the guide rim 15A-3. A pair of tapered latch bosses 35 are provided on the upper rear edge of the front contact enclosure 31. The plug connector 2 may be a conventional shielded plug connector and will be described briefly. In Figures 1 and 2, the plug connector 2 consists mainly of an insulating housing 50, a metal shell 60 for covering the contact portions of male contacts 55 which are mounted in the insulating housing 50, and a pair of case parts 70A and 70B for holding the insulating housing 50 and the metal shell 60 between them. A pair of latch devices 80 are provided on opposite sides of the case parts 70A and 70B. A cable 90 extends from the rear of the case parts 70A and 70B. The respective conductors 91 of the cable 90 are terminated to the rear portions of the corresponding male contacts 55. A method of assembling the receptacle connector 1 will be described. (1) The insulating housing 30 having an array of female contacts 40 is inserted into the shielding shell 20 from the back so that the latch apertures 26 of the shielding shell 20 engage the latch bosses 35 of the insulating housing 30 for locking them to form an insulating-shielding housing assembly. (2) This assembly is then inserted into the mount opening 12 of the mounting frame 10 such that the guide rims 15A-3 may fit into the guide grooves 33-4 of the latch device 33. Consequently, the latch bosses 33-2 of the latch levers 33-1 are brought into contact with the tapered rear ends 15A-2 of the vertical walls 15A, flexing the latch levers inwardly. Finally, the latch bosses 33-2 are snapped into latch recesses 15A-1 of the vertical walls 15A to lock the insulating housing 30 to the mounting frame 10. This completes an assembly of the receptacle connector 1. The structure in which the shielding shell 20 is inserted through the mounting frame 10 is advantageous. That is, since the shielding shell 20 and insulating housing 30 are easy to attach to or detach from the mounting frame 10, when the PCB becomes faulty, it is easy to replace the PCB without removing the mounting screws of the mount frame 10 which has been secured to a panel or the like. As best shown in Figure 2, there is defined a circumferential channel 12'' between the stepwise extended edge 12' of the mounting frame 10 and the shielding shell 20. When the plug connector 2 is plugged into the receptacle connector 1 mounted on the PCB 95, the shielding shell 60 of the plug connector 2 is fitted into the circumferential channel 12". This tends to increase the length of the shielding shell 20 fitted into the shielding shell 60 and decreases the length of the receptacle connector 1 by that much, thus providing a compact electrical connector. In Figures 3 and 4, there is shown a PCB receptacle connector according to another embodiment of the invention. A shielding shell 20A and an insulating housing 30A are similar to those of Figures 1 and 2, and like reference numerals denote identical or equivalent parts or components of Figures 1 and 2 and repetitious description will be omitted. As best shown in Figure 3, the shielding shell 20A has a longer flat rear cover 23A than the rear cover 23 of Figure 1. This rear cover 23A has a bending groove 28A along a line parallel to the rear edge. As best shown in Figure 4, the rear cover 23A is bent by 90 degrees along this bending groove 28A to form a vertical section 27A for covering the rear portions of contacts 40. A pair of latch lugs 29A are provided on opposite lower sides of the vertical section 27A. On the other hand, a pair of latch grooves 33A-5 are provided on both latch devices 33A. To mount the shielding shell 20A over the insulating housing 30A, first of all, insert the insulating housing 30A into the shielding shell 20A from the back and then bend the rear cover 23 by 90 degrees along the bending groove 28A. Finally, bend the latch lugs 29A into the latch grooves 33A-5 of the latch devices 33A by means of a simple tool. The invention has been described by way of a PCB electrical connector but it should be noted that the invention is applicable to electrical connectors of other types such as attached to an equipment panel without mounting on a PCB or not attached to any panel at all. The electrical connector according to the invention has the following advantages. (1) The simply structured shielding shell covers the exposed portions of contacts, thus preventing the adhesion of dirt and dust to the contacts and accidental touching by the operator as well as providing EMI shielding. (2) The shielding shell and insulating housing are simple in structure, easy to attach or detach and assemble, low at the unit manufacturing cost, and easy to replace the insulating housing or shielding shell with a new one. (3) With the structure shown in Figures 3 and 4, the rear portion of the insulating housing is covered completely with the vertical section so that there is less possibility that dirt and dust adhere to the contacts. In addition, more effective EMI shielding is provided. (4) Since the insulating housing containing contacts is detachable from the shield housing, it can be replaced without difficulty, with the shield housing attached to the equipment panel or mating connector. Consequently, when the contact-containing insulating housing becomes faulty, it can be readily replaced with a new one so that it is not necessary to discard the entire electrical connector. (5) The front end of the shielding shell of a plug connector is fitted into the circumferential channel of the receptacle connector, ensuring the necessary length for the shielding shells to engage each other and sufficient resistance to plugging and unplugging forces and/or cable load. (6) Since the front end of the shielding shell of the plug connector is fitted into the circumferential channel of the receptacle connector, the axial length of the receptacle connector can be decreased by that much, thus making the entire connector smaller and lighter and the mounting density on a PCB higher.

Claims: An electrical connector comprising: a receptacle connector including a first insulating housing (30) containing a plurality of first contacts (40) and a first shielding shell (20) disposed so as to enclose contact portions of said first contacts (40); a plug connector (2) including a second insulating housing (50) containing a plurality of second contacts (55) and a second shielding shell (60) disposed so as to enclose contact portions of said second contacts (55); mounting means (10) for mounting said first shielding shell (20) on an object and defining with said first shielding shell (20) a circumferential channel (12") into which a front end of said second shielding shell (60) is to be fitted; said first insulating housing (30) having a front contact enclosure (31) to enclose said contact portions of said contacts (40); said first shielding shell (20) having a front enclosure (21) into which said front contact enclosure (31) is fitted; and said mounting means (10) having a central opening (12) for receiving said front enclosure (31) and a stepped edge (12') around said central opening (12) so as to define with said first shielding shell (20) said circumferential channel (12") into which said front end of said second shielding shell (60) is to be fitted to make electrical connections between said first and second shielding shells.

Inventors: NAKAMURA MASARU, YAMAGUCHI MASAO, NAKAMURA, MASARU, YAMAGUCHI, MASAO
Applicants: HIROSE ELECTRIC CO LTD, HIROSE ELECTRIC CO., LTD.
Application year: 1988
Main classification: H01R13
IPC codes: H01R12