DE68922279T2 - Miniature circular din connector. - Google Patents

Description

Miniature DIN circular connectors are used in computers, audio equipment, video equipment, and other electrical devices to enable one such device to be connected to another. Miniature DIN circular connectors comprise a plurality of pin and socket terminals mounted in a non-conductive housing and electrically connected to conductive leads. Such a DIN connector may be mounted on a panel or circuit board of an electrical component, with the terminals of the DIN connector electrically connected to conductive areas on the panel or circuit board. A mating DIN connector may then be mounted on a cable, with its terminals electrically connected to conductive wire leads in the cable. Typically, the board-mounted miniature DIN circular connectors form receptacles with pin-receiving terminals therein, while the cable-mounted DIN connectors form plugs with pin terminals therein. The cable may have a second DIN connector plug at its opposite end for electrical connection to a miniature DIN circular connector in an associated electrical device. In this way, for example, the keyboard or mouse of a personal computer can be connected to its central processing unit. The number and arrangement of pins or sockets in the miniature DIN circular connector can vary, with most DIN connectors containing between three and nine terminals. The particular arrangement of the terminals in the DIN connector and the design of the housings are intended to ensure a polarized coupling of the respective terminals.The circuit board mounted miniature DIN circular sockets include terminals with Ijöt lugs, surface mount contacts or similar contact devices for establishing an electrical Connection to appropriate conductive areas of the PCB. The very high circuit density on the PCB requires extremely precise positioning of the PCB contact devices of each terminal to ensure that the circuits are properly completed by the DIN connector. This accuracy becomes both more difficult and more important as circuit density increases and DIN connector size decreases.

Government agencies insist on strict electromagnetic interference standards to ensure that electromagnetic energy generated by cables and electrical equipment does not interfere with other electrical equipment or telecommunications equipment. The United States Federal Communications Commission has strict standards for controlling the level of electromagnetic interference.

DIN connectors can be a source of electromagnetic interference. Contacts in the connector can be a source of electromagnetic interference. DIN connectors are often mounted to cover an opening in the shield of the electronics for which the connector provides the external connections. The DIN connector can create the opportunity for electromagnetic interference from the electronics to pass through the connector opening if the connector is inadequately shielded. DIN connectors can cause the cable shield of a connected cable to emit electromagnetic interference if the shield is not properly grounded through the DIN connector.

The circuit density in virtually all electrical devices has increased in recent years due to a general reduction in the size of devices and/or an increase in the complexity of the circuit design. The increased circuit density has required correspondingly smaller electrical connectors of all types, including miniature circular DIN connectors. Furthermore, the increased circuit density in the vicinity of the electrical connectors has significantly reduced the choices available for achieving certain functions, such as electromagnetic interference control. In addition, the smaller electrical connectors required by the increased circuit densities have made it extremely difficult to provide female terminals that can exert an acceptable contact pressure while providing adequate resilience after multiple connections and reconnections. In this regard, it should be remembered that miniature circular DIN connectors used in computers currently on the market can define a cube of only about 1.25 cm² (0.50 square inches) in which 3 to 9 terminals and the necessary electromagnetic interference shields are arranged. The 3 to 9 terminals in this 1.25 cm² (0.50 square inch) DIN connector may be required to exert coupling normal contact forces between 50 to 100 g per contact and to demonstrate satisfactory performance after repeated coupling and decoupling operations.

An extremely effective miniature terminal that can be incorporated into a miniature DIN circular connector is described in EP-A-Q 363 170. However, EP-A-0 363 170 does not specifically address structures for dealing with electromagnetic interference in miniature DIN connectors. Similarly, EP-A-0 363 170 does not address the difficulties associated with the safe and accurate location of terminals in a DIN connector.

The prior art includes attempts to provide electromagnetic interference shielding for DIN connectors. For example, US-A-4,493,525, issued to Hall et al. on January 15, 1985, shows a DIN receptacle having an annular groove with a communicating recess adapted to receive a grounding spring for contacting the counter shield on a plug. No external shield for the connector housing is provided in US-A-4,493 b25. However, in certain embodiments, a front shield extends entirely over the front face of the connector. All of the embodiments of the ground terminal and front shield described in US-A-4 493 525 are electrically connected to the shield of a DIN plug by one or more projecting sheet metal contacts and are connected to ground by contacts extending externally from the housing to the circuit board or chassis to which one surface of the connector is attached. Formations very similar to those shown in certain embodiments of US-A-4 493 525 are also shown in DE-B-1 515 850, published January 2, 1970, and in DE-A-2 733 634, published February 8, 1979.

Another DIN connector which utilizes an electromagnetic interference shield is shown in US-A-4,637,669, issued to Tajima on January 20, 1987. The connector of US-A-4,637,669 comprises a base attachable to a circuit board, panel or the like, and a housing attachable to the base. The housing is constructed to loosely receive a plurality of conductive terminals at intermediate locations therein, and is further provided with means for receiving an annular shield around portions of the housing in which the terminals are mounted. An annular sheet metal contact having an open elliptical cross-section is provided to engage the shield of the DIN plug, providing a strong engagement force. and to shield the terminals. The engagement force generated by the ring contact is due to deformation of the opposing sheet metal parts of the ring contact by the connector shield. The DIN connector shown in US-A-4 637 669 further includes an outer shield which is electrically and mechanically connected to the annular inner contact of the connector. The outer shield is constructed to extend over the top of the DIN connector housing down two opposite side walls of the housing and into the vicinity of the printed circuit board. Both the ring contact and the outer shield of US-A-4 637 669 are electrically connected to ground only by terminals extending from the base which is mountable on a printed circuit board. The three-sided outer shield of US-A-4 637 669 and the associated annular inner contact are intended primarily to act as a single effective shield against electromagnetic interference.

Many EMI shielded DIN connectors are designed to provide the shield for EMI emissions generated at the cable/DIN interface. However, it has now been found that in many applications a larger amount of EMI emissions is generated from the computer or other such electrical device to which the DIN connector is mounted. In many such cases, the EMI shield that the cable/DIN connector interface is designed to shield actually acts as an antenna that, instead of rejecting it, generates the larger amounts of EMI generated by the electrical device to which the DIN connector is mounted.

It is an object of the present invention to provide an improved DIN connector.

US-A-4 637 669 describes a connector according to the preamble of claim 1. The present invention is characterized by the features of the characterizing part of claim 1.

Summary of the invention

The present invention is directed in one aspect to a miniature DIN connector receptacle that may include a mating side for connection to a DIN connector plug and a circuit board mounting side for mounting to a circuit board, panel, or the like. The miniature DIN connector may define a rectangular base configuration that includes a non-conductive molded body housing having a plurality of terminals mounted therein. The terminals mounted in the housing of the miniature DIN connector may include pin-receiving contact areas configured to mate with corresponding pins on a DIN plug. In particular, the terminals may be pin-receiving terminals with resiliently supported cantilevered dual bars as disclosed in copending application Serial No. 225,001 and as further described and illustrated herein. Each terminal may include circuit board contact means, such as solder tabs, for leading to conductive areas of the circuit board. The housing may include channel means for positively positioning the circuit board contact means of the respective terminal. The housing may further be constructed to allow connection between the outer shield and the shield of the DIN connector plug.

A ring-shaped conductive shield against electromagnetic interference can be mounted in the housing so that it can be seen from the coupling side of the connector and in the substantially around the pin-receiving contact areas of the terminals therein. The annular internal electromagnetic interference shield is constructed for electrical contact with a corresponding shield on a DIN plug which is to be coupled to the present miniature DIN circular connector. The annular internal shield may include means for engaging the shield of the DIN connector plug and thereby increasing the forces required for uncoupling. The annular internal electromagnetic interference shield includes contact means for grounding the annular internal shield to the circuit board to which the present miniature DIN circular connector is mountable. The contact means for grounding the annular internal shield may further include ground contacts extending into recesses in the mating side of the housing and projecting from the mating side to contact a panel abutting the mating side of the connector. The annular barrel shield may be further shaped to include an opening allowing a direct electrical connection between the outer shield and the shield and the shield of a matable DIN connector plug.

The miniature DIN circular connector of the present invention may further comprise a non-conductive base engageable with the housing. The base may comprise aperture means for receiving the circuit board contact means of the respective terminals to be electrically connected to the conductive areas on a circuit board. The aperture means in the base may cooperate with the channel means of the housing for positively and accurately positioning the circuit board contact means of each terminal. For example, the base may comprise an array of apertures into which solder tabs of the terminals are inserted. The base may further include guide means for guiding the housing into proper position to ensure alignment of the solder tails or like circuit board contact means of the terminals with the openings in the base. More particularly, the base may include a generally upright rear wall against which portions of the housing may be slidably advanced. The base may also include resilient latch means for lockingly retaining the housing thereon. The latch means may include ramps which act both to guide the housing into proper alignment and to facilitate flexure of the resilient latch means for subsequent locking engagement with the housing.

The miniature DIN circular connector further includes an external electromagnetic interference shield that may form an external surface for the entirety of the DIN connector, excluding the front mating side and the bottom circuit board mounting side. In particular, the shield may be constructed to substantially cover the top, the two opposite sides, and the rear of the miniature DIN connector. In this regard, the top of the miniature DIN connector is defined as its area opposite the circuit board to which the miniature DIN connector is mounted. The rear is defined as its area opposite the mating side of the miniature DIN connector in which a mating DIN connector is received. The opposite sides therefore extend substantially continuously between the mating and rear sides of the miniature DIN connector. Therefore, the external shield substantially defines the external surface zone of the connector excluding the mating and mounting sides. The outer shield of the present miniature DIN connector may be formed from a subunit of a metallic material. The outer shield may comprise a contact device for grounding the outer shield to the circuit board. The outer shield may further include ground contacts extending into recesses in the mating side of the housing and projecting from the mating side to contact a panel abutting the mating side of the connector. The outer shield is electrically connected to the shield of the DIN connector plug to which the present miniature DIN circular connector is coupled by a low impedance connection. In particular, the outer shield may include a deflectable connection device arranged to be contacted by the shield of the DIN connector plug upon mating. The deflectable connection device may be arranged to extend through openings or slots in the housing and the annular inner shield of the miniature DIN circular connector. Preferably, the deflectable contact means contacts the shield of the connector plug to form a large contact area and to exert a substantial force so as to form a low impedance electrical connection from the outer shield to the shield of the DIN connector plug. The deflectable connection means may include means for engaging the shield of the DTN connector plug to increase the forces required for disengagement.

Some ways of carrying out the present invention will now be described in detail, by way of example, with reference to the drawings which show several specific embodiments.

Short description of the drawings

Fig. 1 is an exploded perspective view of a DIN connector according to the present invention.

Fig. 2 is a rear view of the housing of the present DIN connector.

Fig. 3 is a cross-sectional view taken along line 3-3 of Fig. 2.

Fig. 4 is a front view of the base of the DIN connector.

Fig. 5 is a top view of the base.

Fig. 6 is a cross-sectional view taken along line 6-6 of Fig. 5.

Fig. 7 is a perspective view of the pin contact portion of a terminal for use in the DIN connector.

Fig. 8 is a side view of an inner shield for the DIN connector.

Fig. 9 is a plan view of the bottom of the inner shield.

Fig. 10 is a front view of an outer shield of the present DIN connector.

Fig. 11 is a side view of the outer shield.

,Fig. 12 is a front view of the assembled DIN connector.

Fig. 13 is a cross-sectional view taken along line 13-13 of Fig. 12.

Fig. 14 is a plan view of the bottom of the assembled DIN connector.

Fig. 15 is a side view of the assembled DIN connector.

Fig. 16 is a partial cross-sectional view similar to Fig. 13, but showing a different outer and inner shield.

Fig. 17 is a cross-sectional view similar to Fig. 16, but illustrating a second alternative embodiment of the shield.

Fig. 18 is a cross-sectional view similar to Figs. 16 and 17, but illustrating a third alternative design for the shields.

Fig. 19 is a cross-sectional view of a fourth alternative design for an external shield.

Fig. 20 is a side view of an annular inner shield for use with the outer shield shown in Fig. 19.

Fig. 21 is a cross-sectional view similar to the views shown in Figs. 16 through 18, but illustrating a fifth alternative embodiment of the outer shield having means on the outer shield for engaging the shield of a DIN connector plug.

Fig. 22 is a cross-sectional view similar to Figs. 16, 17 and 18, but illustrating a fifth alternative design for the shields.

Fig. 23 is a front view of the external shield of the present DIN connector including the construction of Fig. 22.

Fig. 24 is a cross-sectional view taken along line 2-2 of Fig. 23.

Fig. 25 is a perspective view of a housing with recesses in the front surface for grounding contacts of outer and inner shields.

Fig. 26 is a perspective view of the outer shield with grounding contacts for engaging recesses in the front face of the housing.

Fig. 27 is a perspective view of the internal shield with grounding contacts for extending into recesses in the front face of the housing.

Fig. 28 is an exploded perspective view of an annular inner shield as shown in Figs. 16 to 18 and a matable DIN connector plug with means for enhancing mutual engagement forces.

Detailed description of the illustrated embodiments

The circular miniature DIN connector receptacle 20 shown in Figures 1 and 12-15 includes a housing 22 molded as a unit from a non-conductive plastic material. The housing 22 includes a plurality of through-openings for receiving the pin-receiving contact portions of electrically conductive terminals 24 and a corresponding plurality of channels for receiving the solder tabs 25 of the terminals 24. The terminals 24 and the terminal receiving formations on the housing 22 are described and illustrated in detail below. It is to be understood that not all of the terminals 24 are illustrated in Figure 1. It is further to be understood that the respective solder tabs 25 have different respective configurations.

The housing 22 is designed to receive a conductive inner shield 26 of annular basic shape, sized to substantially surround the pin-receiving contact areas of the terminals 24, to provide a ground reference contact for electrical signals, and to provide suitable shielding against electromagnetic interference at the interface between the terminals 24 of the circular miniature DIN connector 20 and the corresponding pin terminals of a mateable DIN plug (not shown). The annular inner shield 26 is provided with a ground contact 28 which enables the inner shield 26 to be grounded to a printed circuit board (not shown) to which the present DIN connector 20 is mountable. The annular inner shield 26 has an open cross-section which is aligned with an opening 55 of the housing 22.

The housing 22 is engageable in locking engagement with a base 30 which is integrally molded from a non-conductive plastic material which is preferably, but not necessarily, the same material from which the housing 22 is molded. As discussed and illustrated below, the base includes an array of apertures extending therethrough for receiving and positively positioning the solder tails 25 of the terminals through mounting openings in the circuit board.

The miniature DIN connector 20 further includes a conductive outer shield 32 which surrounds four outer sides of the housing 22 and the base 30 in the assembled state to provide further shielding against electromagnetic interference, and in particular, shielding against electromagnetic interference generated by the electrical component to which the circular miniature DIN connector 20 is attached. The outer shield 32 also provides an RF ground for the shield of a mateable DIN connector (not shown) to which the outer shield is electrically connected by a low impedance contact 57. The outer shield 32 includes a contact 33 which allows the shield 32 to be grounded to the circuit board. The inner shield and the outer shield 32 are not electrically or mechanically connected to one another. Rather, the inner and outer shields 26, 32 are separated by the housing 22 and the base 30 to perform separate but complementary shielding functions with separate grounds to the circuit board.

The housing 22 is shown in further detail in Figures 2 and 3. In particular, the housing 22 includes a rear terminal mounting face 34, a front connection face 35, a top face 36, a bottom face 37, and opposing faces 38 and 39. A plurality of terminal mounting apertures 40a-h extend entirely through the housing 22 from the rear face 34 thereof to the front connection face 35. Each mounting aperture 40a-h intersects the front connection face 35 of the housing 22 at a substantially circular connection aperture 42a-h having a tapered entrance to facilitate the coupling of a DIN plug to the circular miniature DIN connector 20. The rear portion of the mounting apertures 40a-h are shown in Figure 2 as having a basic rectangular cross-sectional shape. The rectangular cross-sectional shape of the terminal mounting openings 40 corresponds to the cross-sectional shape of the terminals as shown in Fig. 1 and in further detail in Fig. 7. Other shapes and dimensions for the terminal receiving openings 40a-h may be required for terminals having other shapes. The openings 40a-h include slots, such as slots 44b, e and g in Fig. 3, for receiving tabs on the terminals 24 to prevent vertical upward sliding of the terminals.

The rear side 34 of the housing 22 includes a plurality of tab receiving channels 46a-h that communicate with the terminal receiving openings 40a-h, respectively. The channels 46a-h are sized and arranged to receive and guide the solder tabs 25 extending from the respective terminals 24 mounted in the openings 40a-h. It will be understood that the terminals, generally designated by the reference numeral 24, have respective solder tabs 25 of dedicated length and shape depending on the particular channel 46a-h for which they are intended. As illustrated in Figure 2, the channels 46d, 46g and 46h may be spaced a first distance from the back surface 34 by about 0.051 cm (0.020 inches), while the channels 46a, 46b, 46c and 46e may be spaced a second distance from the back surface 34 by about 0.097 cm (0.038 inches). Thus, the various positions of the channels 46a-h provide the ability for the solder tails 25 of the terminals 24 to form two parallel, spaced-apart rows that may be selectively connected to electrically conductive areas on the printed circuit board. The alignment of the solder tails provided by the channels 46a-h ensures positive positioning and alignment of the solder tails 25 with respect to the sides 38 and 39 of the housing 22, thereby enabling the insertion of terminals 24 into the housing 22 to be automated and also enabling the assembly of the housing 22 to the base 30 to be readily automated. In this configuration, the slots 44 engage the tabs on the terminals 24 as set forth below to prevent top to bottom movement of the terminals 24 with respect to the housing 22, while simultaneously engaging the channels 46 with the solder tails 25 to prevent side to side movement.

The housing 22 further includes an opening 48 of annular basic shape extending into the front surface 35 thereof. The opening 48 is sized to slidably receive the annular inner shield 26. A housing opening 55 extends from the top 36 of the housing 22 to the annular opening 48. The opposing sides 38 and 39 of the housing 22 include locking bars 50 and 52 for enabling locking engagement of the housing 22 with the base 30 as discussed below. The housing 22 further includes a front flange 54 against which the outer shield 32 abuts.

The base 30 of the miniature circular DIN connector 20 is further illustrated in Figures 4 through 6. In particular, the base 30 includes a bottom wall 56 for mounting generally adjacent to a printed circuit board, panel or the like. The bottom wall 56 includes standoffs 58 which allow the main portion of the DIN connector 20 to be in a slightly spaced relationship to the corresponding circuit board to facilitate flux flushing.

The base 30 further includes a rear wall 60 which facilitates guiding the housing 22 into position and acts to insulate and protect the terminals 24 mounted in the housing 22. The rear wall 60 also acts to prevent front-to-back movement of each terminal 24, thereby retaining each lug 25 in its associated channel 46 of the housing 22. Openings 62a-h extend through the bottom wall 56 of the base 30 adjacent the rear wall 60 for receiving the solder lugs 25 of the terminals 24 extending from the channels 46a-h in the housing 22. The openings 62a-h each have tapered leads to facilitate alignment and guiding of the solder lugs 25. Alignment of the solder lugs 25 with the openings 46a-h h is further facilitated by the rear wall 60. The base 30 is further provided with deflectable latches 64 and 66 which come into locking engagement with the strips 50 and 52 of the housing 22, respectively.

As noted above, the terminals 24 for mounting in the housing 22 have contact areas substantially as described in EP-A-0 363 170. Briefly, the contact area of the terminal 24 is illustrated in Fig. 7 and has a front end 72 which is positioned generally adjacent to the front face 35 of the housing 22. A rear end 74 is not fully shown in Fig. 7, but includes the rectangular solder tail 25 as shown in Fig. 1 and further in Figs. 11 to 14 below. The stamped shape of the solder tails is chosen to follow the shape of the respective channels 46a-h in the housing 22. The rear end 74 further includes a tab 75 slidably received in the slots 44 of the housing to prevent up-and-down movement of the connector 24 with respect to the housing 22.

The terminal 24, as shown in Fig. 7, includes a recessed portion 80 and two spaced apart upright legs 82 and 84. Cantilevered contact bars 86 and 88 extend forwardly from the legs 82 and 84 to the front end 72 of the terminal 24. The contact bars 86 and 88 are shaped to form spaced apart inwardly directed convex contact surfaces 90 and 92 which are resiliently urged apart upon insertion of a pin terminal therebetween. The front ends of the contact bars 86 and 88 further include L-shaped connecting members 94 and 96 which extend generally perpendicularly from the cantilevered contact bars 86 and 88 at the front end 72 of the terminal 24. An elastic strip support 98 of U-shaped basic shape extends between the connecting links 94 and 96 and connects them. The U-shaped The resilient strip support member 98 includes two arms 100 and 102 extending integrally from the connecting portions 94 and 96, respectively, and a loop 104 integrally connecting the arms 100 and 102. The strip support member 98 has the effect of increasing the resilient response range of each strip 86, 88 to a greater outward displacement while simultaneously providing greater force contact forces against a pin inserted into the terminal 24. A more detailed description and discussion of the terminal 24 is contained in European Patent Application No. 89,31 0135.2.

The inner shield 26 of the circular miniature DIN connector 20 is shown in further detail in Figures 8 and 9. In particular, the inner shield 26 includes an outwardly flared entrance 106 which generally conforms to the shape of the mounting opening 48 in the housing 22. The inner shield 26 also has a contact 28 extending therefrom for attachment to a suitable ground on the circuit board. The contact 28 is sized to fit through corresponding slots in both the housing 22 and the base 30. As shown most clearly in Fig. 9, the inner shield 26 further includes locking tabs 110 and 112 extending from their opposite sides for locking engagement with corresponding portions of the annular-shaped opening 48 in the housing 22 for receiving the inner shield 26.

The outer shield 32 is shown in further detail in Figures 10 and 11. In particular, the outer shield 32 is formed from a unitary piece of metallic material having a thickness of about 0.041 cm (0.016 inches). The outer shield 32 includes opposed generally parallel side walls 114 and 116, a top wall 118 integrally extending between the side walls 114 and 116 and generally perpendicular to the thereto, and opposing coplanar rear wall portions 120 and 122 extending integrally from and generally perpendicular to the side walls 114 and 116. The outer shield 32 further includes a low impedance plug shield contact, generally designated 57 in FIG. 1, extending from the top surface 118. Specific embodiments of the plug shield contact 57 for providing low impedance contact with a plug shield of a DIN connector plug are described in detail below. The outer shield 32 further includes contacts 124 and 33 extending from the side walls 114 and 116 to enable the outer shield 32 to be grounded to the circuit board to which the circular miniature DIN connector 20 is mounted. The outer shield 32 further includes locking tabs 128 through 134 extending from the side walls 114 and 116, as shown in Figs. 10 and 11, which are engageable with corresponding portions of the housing 22 to prevent top-to-bottom and front-to-back movement of the outer shield 32 with respect to the housing 22, as discussed below.

The circular miniature DIN connector 20 is shown in exploded form in Fig. 1 and in its assembled form in Figs. 12-15. The circular miniature DIN connector 20 can be assembled by first inserting the terminals 24a-h into the corresponding openings 40a-h in the housing 22. The solder tabs 25a-h on the respective terminals 24a-h can be bent prior to insertion into the openings 40a-h or can instead be bent as part of the insertion process. A plurality of the terminals 24a-h can be inserted simultaneously using a terminal insertion device. The insertion of the terminals 24a-h into the opening 40a-h is such that their solder tabs 25a-h are positioned in the channels 46a-h, respectively.

The terminals 24a-h further include tabs 75 engageable in the tab receiving slots 44a-h of the corresponding openings 40a-h to prevent relative movement of the terminals 24a-h toward and away from the bottom 37 of the housing 22. Thus, each solder tail 25a-h is prevented from significant transverse movement through the corresponding channels 46a-h and is also prevented from moving toward or away from the bottom 37 of the housing 22 by the engagement of the tabs in the corresponding slots 41 of the openings 40a-h. As shown in Figures 12 and 13, the opposing convex contact surfaces 90 and 92 of the terminals 24a-h are in basic alignment with the openings 42a-h in the housing for receiving the pin terminals of a DIN plug (not shown) which is coupled to the connector 20.

Assembly of the miniature circular DIN connector 20 may proceed by pressing the annular inner shield 26 into the annular opening 48 of the housing 22; however, the inner shield 26 may also be attached as the last step in assembling the miniature circular DIN connector 20. The subassembly comprising the housing 22, the terminals 24a-h and the inner shield 26 may be mounted to the base 30 by inserting the solder tabs 25a-h of the terminals 24a-h into the corresponding openings 62a-h of the base 30. Proper alignment of the solder tabs 25a-h with respect to the openings 62a-h in the base 30 is accomplished both by the extended leads to the openings 62a-h and by the guiding function performed by the back wall 60 of the base 30. The solder lugs 25a-h are held laterally stationary with respect to the housing 22 by the corresponding channels 64a-h, thereby ensuring a precise assembly to the base 30. The movement of the housing 22 toward the base 30 causes the latches 64 and 66 to be bent apart. When the base 22 is fully seated in the housing 30, the pawls 64 and 66 resiliently return to their unloaded state and engage the locking bars 50 and 52 of the housing 22.

The outer shield 32 is engaged over the housing 22 assembled with the base 30, separating the inner and outer shields 26, 32. In particular, the side walls 114 and 116 of the outer shield 32 generally abut the sides 38 and 39 of the housing 22 and the corresponding sides of the base 30. The top wall 118 of the outer shield 32 engages the top 36 of the housing 22, while the rear walls 120 and 122 of the outer shield 32 engage and enclose the rear wall 60 of the base 30. The plug shield contact 57 extends through the housing opening 55 and between the ends of the annular shield 26 so that the contact 57 is separated from the annular shield 26. The outer shield 32 extends over the bottom wall 56 of the base 30 and generally to the spacers 58 thereof. Thus, the outer shield 32 approximately abuts the circuit board to which the circular miniature DIN connector 20 is attached along three sides of the DIN connector 20. The retention of the outer shield 32 to the housing 22 from top to bottom is accomplished by tabs 128 and 130 which engage corresponding recesses in the housing 22. Similarly, front to back movement of the outer shield 32 with respect to the housing 22 and base 30 is accomplished by the tabs 132 and 134.

The assembled circular miniature DIN connector 20 can be attached to a printed circuit board (not shown) in such a way that the positively positioned solder lugs 25a to 25b are inserted through corresponding openings in the printed circuit board and are connected to specified conductive areas of the circuit board. The contact 28 extending from the inner shield 26 is suitably grounded to the circuit board. Similarly, the contacts 124 and 33 of the outer shield 32 are suitably grounded to the circuit board. However, the inner shield 26 and the outer shield 32 are not electrically connected to one another in the DIN connector 20.

The external shield 32 of the DIN connector 20 functions to suppress electromagnetic emissions by providing a shield to emissions from the connector and by providing a shield that prevents emission through an opening in a shield adjacent to the mounting surface 35. DIN connectors often connect to electronic equipment contained within a shielded enclosure. When positioned adjacent to an opening in the shield, the external shield 32 of the DIN connector 20 functions to prevent electromagnetic emissions from the electronic equipment from being emitted through the opening.

The cable connected to a DIN connector plug (not shown) which is coupled to the miniature circular DIN connector 20 can become a source of electromagnetic interference emissions. To avoid such emissions, a low impedance ground connection is achieved by providing a direct, minimum path connection between the plug and the external shield of the DIN connector. Effective versions of this direct, minimum path connection between the external shield 32 and the DIN connector plug are described in the following paragraphs and illustrated in Figures 16 through 24. The construction of the embodiments illustrated in Figures 16 through 24 can best be understood by initially referring to Figure 1 above. . In particular, with reference to Fig. 1, the annular inner shield 26 shown therein is provided with a longitudinal slot 27 generally in the upper region of the inner shield 26. The slot 27 may be up to about one-third of the circumference of the inner shield 26. The embodiments of the invention illustrated in Figs. 16-24 include the annular outer shield 26 as illustrated in Fig. 1 with the longitudinal slot 27 at its top. The specific embodiments of the aperture 55 and contact 57 shown in Figs. 16-24 are described in detail below.

Referring to Fig. 16, a miniature circular DIN connector 220 is shown having a housing 222 having a top wall 236. The top wall 236 is provided with a centrally located opening 237 substantially aligned with the slot 27 in the inner shield 26. The miniature circular DIN connector 220 of Fig. 16 further includes an outer shield 232 having a top wall 218. The top wall 218 is stamped to form a deflectable contact 238 which extends through the opening 237 in the housing 222 and through the slot 27 in the inner shield 26. The length and angular orientation of the deflectable contact 238 is selected to ensure that the contact 238 provides a direct, minimal path connection between the outer shield 232 and the shield of a DIN connector plug (not shown) when the plug is mated to the miniature circular DIN connector 220.

Figure 17 shows another alternative miniature circular DIN connector, generally designated by the reference numeral 320. The DIN connector 320 includes a housing 322 having a top wall 336 with an opening or slot 337 formed therein. The opening or slot 337 formed in the housing 322 is longer than the comparable opening 237 shown in Figure 16 above. The DIN connector 320 further includes an outer shield 332 having a top wall 318 having a deflectable contact 338 projecting from a rear location 340 on the outer shield 332 toward the front end of the outer shield 332. The front portion of the deflectable contact 338 is bent into the slot 27 of the annular inner shield 26 to form a contact surface 342 which engages the shield of the DIN connector plug when the plug is mated to the circular miniature DIN connector 320. The bending shape of the contact surface 342 of the bendable contact 338 is designed to ensure smooth entry of the DIN connector plug into the circular miniature DIN connector 320. The shape of Fig. 17 can provide a higher contact force than the shape of Fig. 16 and also provides a larger outer shield area. In particular, the initial bending of the contact 338 forces the end 344 of the contact bar 338 into contact with the top wall 318 of the outer shield 332. Further insertion of the DIN connector plug requires some bending substantially about the contact point 342, thereby achieving a high normal contact force. This interaction between the bendable contact 338 and the shield of the mateable DIN connector plug effectively and desirably increases the force required for release or uncoupling. It will be appreciated that this design also achieves a substantially minimum path length between the outer shield 332 and the shield of the DIN connector plug, the minimum path length being formed between the contact surfaces 342 and 344 of the deflectable contact 338. The circular miniature DIN connector 420 shown in Fig. 18 includes a housing 422 similar to the housings shown in Figs. 16 and 17. In particular, the housing 422 includes a top wall 436 with an opening 437 formed centrally therein. The Outer shield 432 has a top wall 418 with a contact 438 integrally extending from the front face 440 of outer shield 432. Contact 438 is positioned to extend into slot 27 formed in annular inner shield 26 for direct contact with the shield of the mateable DIN connector plug (not shown). Deflectable contact 438 is shaped to form a plug contact surface 442 and a shield contact surface 444. For the reasons explained in the previous paragraph, high contact forces can be developed between deflectable contact 438 and the shield of the mateable DIN connector plug. These high contact forces can achieve the desirable effect of increasing the forces required for decoupling. In addition, the design of contact 438 as shown in Fig. 18 provides a substantially minimal path length between outer shield 432 and the shield of the DIN connector plug.

19 and 20 show yet another embodiment for achieving a direct connection between the outer shield and the shield of the mateable DIN connector plug. In particular, FIG. 19 shows an outer shield 532 having a top wall 518 and a rear wall 536. A deflectable contact 538 projects from a location 540 on the rear wall 536 and extends forward to a contact surface 542 for engagement with the shield of the DIN connector plug. The contact 538 is shaped to form a second contact surface 544 for contacting the top wall 518 of the outer shield 532. As with the previously described embodiments, the deflectable contact 538 achieves high contact forces against the DIN connector plug and a minimal travel length between the top wall 518 of the outer shield 532 and the shield of the DIN connector plug. It is understood that the shielding of the DIN connector plug can be conveniently deformed by a dent or the like to provide means for engagement with the contact surface 542 for further increasing the release force required to uncouple a DIN connector plug from the miniature circular DIN connector utilizing the outer shield 532. To accommodate the outer shield 532, the housing of the circular miniature DIN connector 20 requires a slot in the top wall extending from the rear of the housing. In addition, an annular inner shield 526, as shown in Fig. 20, with an enlarged slot 527 at least adjacent its rear portions may be required. The slot 527 on the rear of the annular inner shield 526 is sized to allow the deflectable contact 538 to directly contact the shield of a mateable DIN connector plug.

Fig. 21 shows yet another embodiment of the miniature circular DIN connector, generally designated by reference numeral 620. In particular, the housing 622 of the DIN connector 620 includes a top wall 636 having an opening 637 centrally located and spaced from both the front and rear of the housing 622. The outer shield 632 has a top wall 618 having a central portion deformed to form a deflectable contact 638 extending through the opening 637 and through the slot 27 in the annular inner shield 26. The deflectable contact 638 forms a contact surface 642 for engagement with the shield of a matable DIN connector plug. The contact surface 642 may be bordered by an engagement surface 644 for engagement with a corresponding formation on the matable DIN connector plug in order to increase the release force required for decoupling. It is understood that the embodiment of the outer shield illustrated in Fig. 2-1 63 presents a substantially minimal path between the outer shield 63 and the mateable DIN connector plug. Additionally, the deflectable contact 638 is formed without interruptions in the outer shield 632, thereby maintaining a substantially maximum surface area for the outer shield 632.

Figures 22, 23 and 24 show yet another embodiment of a miniature circular DIN connector, generally designated by reference numeral 820. In particular, the housing 822 of the DIN connector 820 includes a top wall 836 having an opening 837 centrally located and spaced from both the front and rear of the housing 822. The outer shield 832 includes a top wall 818 having a continuous recess forming a very rigid dimple contact 838 extending from the top 818 of the shield 832 through the slot 27 in the annular inner shield 26. The dimple contact 838 has a central contact surface 842 that extends in the slot 27 of the inner shield 26 without interfering with the inner shield 26. The contact surface 842 has a significant length away from the outer shield 832 and extending axially of the inner shield 26.

As illustrated in Figure 23, the dent contact 838 has a substantially U-shaped cross-section in the plane parallel to the front mounting surface 35, and the contact surface 842 is substantially flat in a plane parallel to the axis of the inner shield 26. As illustrated by Figures 23 and 24, all sides of the dent contact 838 are short extensions from the top of the shield 818. The contact dent 838 is accordingly very rigid and substantially any vertical deflection of the dent contact 838 due to insertion of a DIN connector plug is a result of deflection of the top wall 818. A high normal contact force between the dent contact 838 and the shielding of a DIN plug inserted into the connector results from this design.

Figures 25, 26 and 27 show the housing 900, outer shield 930 and inner shield 960 of yet another embodiment of the miniature circular DIN connector. As shown in these figures, this embodiment of the DIN connector has outer shield extensions 932, 934 and inner shield extensions 962, 964 that extend into front surface recesses 902, 904 and 906, 908, respectively. Two such recesses 906, 908 extend from the inner shield opening 910 into the front surface 912 of the housing 900 and the other two recesses 902, 904 extend from the sides and top of the housing 900 into the front surface 912.

Referring now to Figure 26, the outer shield 930 has outer shield extensions 932, 934 that extend into the front recesses 902, 904 in the front 912 of the housing 900. As shown in Figure 27, the inner shield 916 has inner shield extensions 962 and 964 that extend into the inner shield recesses 906, 908 in the front 912 of the housing 900. The inner shield extensions 962, 964 and the outer shield extensions 932, 934 extend approximately 0.0076 cm (0.003 inches) beyond the front 912 of the housing 900. Preferably, the extensions 962, 964, 932, 934 are abutting against and electrically in contact with a conductive grounding chassis panel (not shown) in which the DIN connector is mounted. The inner shield 960 and outer shield 930 of this embodiment of the circular miniature DIN connector may therefore be grounded by contacts 966, 936 and 938 or alternatively or optionally additionally by contact with the conductive chassis panel through the extensions 962, 964, 932 and 934.

As noted above, it is often desirable to increase the force required for decoupling in order to more positively prevent inadvertent detachment of the DIN connector plug from the circular miniature DIN connector described and illustrated above. Certain embodiments of the direct connection between the outer shield of the circular miniature DIN connector and the mateable DIN connector plug can increase the forces required for decoupling. In alternative embodiments or variations of the embodiments described above, the mateable surfaces of the shield on the DIN connector plug and the annular inner shield of the circular miniature DIN connector can be suitably designed to increase the forces required for decoupling. In particular, Figure 28 shows a DIN connector plug 700 having a generally annular shield 702. The annular shield 702 is characterized by outwardly projecting lugs 704 formed therein. The DIN connector plug is mateable with a corresponding circular miniature DIN connector as described and illustrated above. However, the mateable circular miniature DIN connector includes an annular inner shield 726 having apertures 728 arranged and sized to engage the lugs 704 on the DIN connector plug 700. The engagement of the lugs 704 with the apertures 728 requires increased decoupling forces which substantially prevent accidental decoupling. Instead, the DIN connector plug could be provided with a boss 706 arranged and sized to engage slots 730 formed in the annular inner shield 726. Slots 730 are stamped during formation of locking means for locking mounting of the inner shield 726 in its housing (not shown).

Referring to the drawings, there have been described miniature circular DIN connector sockets having a housing with openings for positively receiving and securing electrical terminals therein. The housing is engageable with a base which in turn is mountable to a circuit board. An inner shield is mountable in the housing so as to substantially surround the terminals therein and is grounded to the circuit board or a conductive chassis panel. An outer shield surrounds four sides of the assembled DIN connector and is separately grounded to the circuit board or a conductive chassis panel. The outer shield is directly connectable to the cable shield of a matable DIN connector plug by a contact which applies a substantial force to the shield of the DIN connector plug over a substantial area to form a low impedance connection to an RF ground. The connection of the outer shield to the DIN connector plug is achieved through slots or openings in the housing and inner shield of the circular miniature DIN connector.

The miniature circular DIN connector can be manufactured with various numbers of terminals mounted therein. The terminals shown and described above are extremely effective, however, advantages of the circular miniature DIN connector can also be achieved with other terminal configurations. The contact extending between the external shield of the miniature circular DIN connector and the shield of the mateable DIN connector plug can take other forms than those illustrated here.

The miniature DIN circular connector sockets described with reference to the drawings have reinforced shielding against electromagnetic interference. They have a low impedance connection from the shield contact of a plug inserted into a DIN connector to an RF ground. The connectors are effective in shielding electromagnetic interference generated by both the cable/connector interface and the electrical component to which the DIN connector is attached. The connectors can be manufactured in a very small size and yet provide acceptable contact forces and the capability of repeated mating and unmating operations. The connectors accurately position the printed circuit board contact means of the terminals therein. The external shield provided can substantially cover the external surface of the connector. A direct low impedance electrical connection is provided between the external shield of the connector and the shield of a matable DIN connector plug inserted into the connector. An electrical ground connection for the shield of the connector is provided via contacts on a surface of the connector.

Claims (18)

1. Miniature DIN circular connector socket (20) for attachment to a circuit board and for receiving a DIN connector plug with a shield extending around it, the DIN connector socket (20) being provided with a non-conductive housing (22) with a coupling side (35) for receiving the connector plug, a bottom side (37), a plurality of further outer sides (34, 36, 38, 39), an inner shielding opening (48) adjacent to the coupling side (35) for receiving an inner shielding (26) of the DIN socket (20) and an area of the shielding of the DIN plug, a plurality of conductive connections (24) mounted in the housing (22), a conductive inner shield (26) mounted in the inner shield opening (48) and having a first contact device (28) for grounding the inner shield (26) to a ground circuit of the circuit board, and a conductive outer shield (32) with a plurality of walls (114,116,118,120,122) substantially surrounding a number of the further outer sides (34,36,38,39) of the housing (22) and a second contact device (33,124) for grounding the outer shield (32) to a ground circuit of the circuit board, characterized in that the housing has a channel (237,337,437,637) between one of the further outer sides (236,336,436,636) and the inner shield opening (48) and the outer shield (32) has a third contact device (238,338,438,538,638,838) which extends through the channel (237,337,437,637) and into the inner shield opening (48) for direct contacting of the Shielding of the DIN plug when the plug is coupled to the socket (20). 2. Miniature DIN circular connector according to claim 1, wherein the inner shield opening (48) extends generally around the coupling regions (86,88) of the conductive terminals (24) and the outer shield (32) forms at least three outer sides of the miniature DIN circular connector. 3. A miniature DIN circular connector according to any preceding claim, further comprising an insulating base (30) having an array of openings (62a-h) extending therethrough for receiving circuit board contact areas (25) of the terminals (24), the base (30) being mountable adjacent the circuit board and having means (64,66) for locking engagement of the housing (22) with the base (30). 4. A miniature circular DIN connector according to any preceding claim, wherein the outer shield (32) extends generally adjacent the bottom (37) of the housing (22) such that the outer shield (32) is generally in abutting relationship with a circuit board to which the DIN connector (20) is mounted. 5. A miniature DIN circular connector according to any preceding claim, wherein the housing (22) has a rectangular parallelepiped basic shape and includes a top wall (36) generally parallel to the bottom (37) of the housing (22), a pair of opposed generally parallel side walls (38,39) and a rear wall (34) generally parallel to the bottom (37) of the housing (22), the outer shield (32) generally conforming to the shape of the housing (22) and including a top wall (118), a pair of opposed generally parallel side walls (114,116) generally perpendicular to the top wall (118), and a rear wall (120,122) which is generally perpendicular to the top wall (118) and to the side walls (114,116), and wherein the third contact means extends through the channel (55) in the housing (22) for contacting the shield of the DIN connector plug coupled to the miniature DIN connector (20). 6. A miniature DIN circular connector according to any preceding claim, wherein the outer shield (32) and the inner shield (26) are electrically and mechanically separated from each other prior to mounting to a circuit board. 7. Miniature DIN circular connector according to any preceding claim, wherein the outer shield (32) forms four outer sides of the DIN connector (20), the DIN connector (20) comprises a socket of rectangular parallelepiped basic shape with a top (118), a bottom (37), opposite sides (114,116), a rear (120,122) and a coupling side (35) for coupling with a DIN connector plug, and the outer shield (32) essentially forms both opposite sides (114,116), the top (118) and the rear (120,122) of the DIN connector (20). 8. Miniature DIN circular connector according to any preceding claim, wherein the third contact means (238) of the outer shield comprises a bendable contact arm (238) punched out of the region of the outer shield (32) adjacent to the top surface (36) of the housing (22) and projecting therefrom for contact with the shield of the DIN connector plug coupled to the miniature DIN connector (20). 9. Miniature DIN circular connector (20) according to any preceding claim, wherein those areas of the outer shield which cover the further outer sides of the housing surrounded, are substantially continuous, and wherein the third contact device (238) of the outer shield (32) is a bendable contact arm (238) which projects from the upper side (218) of the outer shield (232). 10. A miniature DIN circular connector according to any preceding claim, wherein the third contact means (238,438) of the outer shield (232) projects from a region of the outer shield (232,432) generally adjacent the front coupling end (35) of the connector (20). 11. A miniature DIN circular connector according to any one of claims 1 to 9, wherein the third contact means (338,342) of the outer shield projects from a portion of the outer shield (332) generally adjacent the rear surface thereof. 12. A miniature DIN circular connector according to any preceding claim, wherein the third contact means (338,438,538) of the outer shield (432) comprises means (344,444,544) for preventing slight elastic deformation of the third contact means when engaging the shield of the DIN connector plug, so as to increase the forces required to decouple the DIN connector plug from the miniature DIN connector (20). 13. A miniature circular DIN connector according to any preceding claim, wherein the third contact means (838) comprises an indentation in the outer shield (832) extending through the outer shield opening (27) and contacting a conductive shield of a DIN plug to form a current path from a conductive shield of a DIN plug to the outer shield (852) of the DIN connector (20). 14. Miniature DIN circular connector according to claim 13, wherein the indentation forms a substantially flat surface (842) penetrating the inner shield opening (27) for has a contact with a conductive shield of a DIN connector in the inner shield opening (27) along a contact line which runs from the front end (35) of the housing (22) towards the inner shield opening (27). 15. A miniature DIN circular connector according to any preceding claim, wherein (i) the housing (900) has at least one outer shield recess (902,904) in the front end (912) of the housing extending from one side and the top of the housing, and (ii) the outer shield (930) has at least one further contact means in the form of an outer shield extension (932,934) extending from the outer shield into the outer shield recess (902,904) and projecting outwardly from the front end (912) of the housing (900), whereby the outer shield extension (932,934) can abut a panel adjacent the front end of the DIN connector. 16. A miniature DIN circular connector according to claim 15, wherein (i) the housing (900) has at least one inner shield recess (906,908) extending from the inner shield opening (910) in the front end (912) of the housing (900), and (ii) the inner shield (960) mounted in the inner shield opening (910) has a slot aligned with the channel between one of the outer sides and the inner shield opening and at least one inner shield extension (962,964) extending into the inner shield recess (906,908) and projecting outwardly from the front end (35) of the housing (900). 17. A miniature DIN circular connector according to claim 16, wherein (i) the housing (900) has a second outer shield recess in the front end of the housing extending from one side and the top of the housing, and (ii) the outer shield has a second outer shield extension extending from the outer shield into the second outer shield recess and projecting outwardly from the front end of the housing. 18. The miniature DIN circular connector of claim 17, wherein: (i) the housing has a second inner shield recess in the front end (912) of the housing extending from the inner shield opening (910) in the front end of the housing, and (ii) the inner shield has a second inner shield extension extending into the second inner shield recess and projecting outwardly from the front end of the housing.