The present invention is directed to electrical connectors, and more particularly to connectors containing an indication of full mating.

It is desired in certain mating electrical connector assemblies to provide an indication that the pair of connectors is fully mated. For example, in US-A-4,070,557, a shunt is contained within the receptacle connector housing having an array of signal contacts in a plug-receiving cavity, and the shunt includes a deflectable section that is spring biased in engagement with a pair of the contacts when the connector is unmated, and is deflected out of engagement upon receipt of a mating plug connector into the receptacle's cavity during mating, thereby breaking the interconnection of the pair of contacts which become mated with contacts of the plug connector. In US-A-4,725,241 a jack connector housing includes in addition to its signal contacts disposed in a plug- receiving cavity, a set of contacts in a compartment wherein one includes a spring arm in engagement with another of the set until cammed away by a cam member of the jack upon receipt of a plug connector into the cavity during mating; the contacts of the set include sections extending out of the housing for interconnection such as with a circuit board.

Certain electrical connectors are known that possess a mating interface having a selected number of electrical contacts in plug and receptacle connectors, and are sold by AMP Incorporated, Harrisburg, PA, USA as "Universal Serial Bus" connectors, Series A, Part Nos. 787616 and 95-8083-20, that are particularly useful in computer terminals at input/output ports. It is desired to provide a full mating indicator without necessitating any modification of the positions of the contacts along the mating interface.

It is also desired to provide a mating indicator contact member having a repeatedly cleaned contact surface.

The electrical connector of the present invention includes a switch contact member additional to several other contacts without necessitating modification of the contact positions along the mating face of a known connector, nor modification to the contacts thereof. The switch contact is mounted rearwardly of the mating face and includes a connector-engageable portion exposed alongside the mating face at a selected location that necessarily is engaged by a portion of the mating connector when the connectors have been moved into a fully mated condition. The switch contact also includes a contact-engaging section on a deflectable spring arm positioned to engage a selected one of the contacts when the connector is unmated. Upon full mating the spring arm is deflected moving the contact-engaging section out of engagement with the selected contact, breaking an electrical circuit therewith and thus indicating full mating. Upon unmating, the spring arm resiles into engagement with the selected contact reestablishing the circuit to indicate an unmated condition.

In one embodiment the spring arm is positioned along the rearward face of the connector, and the connector-engageable portion extends forwardly from a deflectable end of the spring arm, and the contact- engaging section is also located proximate the deflectable end of the spring arm. When the mating connector abuts the connector-engageable portion, the deflectable end of the spring arm is deflected rearwardly to disengage the contact-engaging section from the selected contact.

In another embodiment, the spring arm is positioned proximate the mating face extending to a deflectable end that defines the connector-engageable portion. The contact-engaging section is located proximate the

deflectable end, engaging a selected other contact thereat in the unmated condition. Upon mating, the deflectable end is urged rearwardly, disengaging the contact-engaging section from the selected contact. Upon unmating, the spring arm resiles into engagement with the selected contact reestablishing the circuit to indicate an unmated condition, and in resiling wipes along the selected contact to remove oxides beginning to form on the switch contact-engaging surfaces thereof. It is an objective of the present invention to provide an electrical indication of a fully mated condition and hence also an unmated condition.

It is a further objective to provide such an indication in a connector having a standard mating interface, namely, a fixed number of contacts establishing a fixed number of circuits with the mating connector, without changing the position of any thereof and thus being matable with commercially available mating connectors. Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which:

FIGURES 1 and 2 are exploded isometric views of the connector of a first embodiment of the present invention from forwardly and rearwardly thereof;

FIGURE 3 is an isometric view of the rear face of the fully assembled connector of FIGS. 1 and 2;

FIGURE 4 is an isometric view of the housing with all contacts assembled thereto including the switch contact;

FIGURES 5 and 6 are top and side longitudinal section views of the connector of FIGS. 1 to 3 after full mating with a mating connector;

FIGURE 7 is an elevation view of an electrical connector containing a second embodiment of the present invention;

FIGURE 8 is a longitudinal section view of the connector of FIG. 7 taken along lines 8-8 thereof, illustrating the switch contact and a selected signal contact in engaged relationship; FIGURE 9 is an isometric view of the housing of the connector of FIG. 7 with signal contacts and the switch contact of the present invention exploded therefrom positioned for insertion thereinto;

FIGURE 10 is a plan view of the housing of FIG. 9 after assembly of the signal contacts and switch contact thereinto;

FIGURE 11 is an isometric view of the assembly of FIG. 10 with part of the housing broken away;

FIGURE 12 is a longitudinal section view of the assembly of FIG. 10; and

FIGURE 13 is an enlarged section view of the connection of the switch contact with a selected contact.

A first embodiment of connector with switch is illustrated in FIGS. 1 through 6, and a second is illustrated in FIGS. 7 through 13.

In FIGS. 1 and 2, connector 10 includes an insulative housing 12, a surrounding shell 14 for shielding, an array of contacts 16,18 and a switch contact 100, that upon full assembly is matable to a mating connector (FIGS. 5 and 6) at a mating face (FIG. 4). Contacts 16,18 include first portions 20,22 defining first contact sections 24,26 exposed along the mating face, body sections 28,30 disposed along passageways 32,34 of housing 12, and legs 36,38 bent at right angles to the body sections rearwardly of housing 12 to conclude in second contact sections 40,42 depending below the connector for connection to circuits of the circuit board (not shown) . It is seen that body sections 28,30 of contacts 16,18 include barbs 44 for self-securing the contacts within passageways 32,34 of housing 12 upon full

insertion, and legs 36,38 include embossments 46 seating atop ledges along leg-receiving channels 48 of the housing to maintain the legs in respective desired positions after assembly and during mounting to a board. Housing 12 is shown to include latches 50 for seating in recesses 52 of shell 14 for retention of the housing within the shell upon insertion into rear end 54 of the shell during assembly (FIG. 3) . Also seen are keys 56 of housing 12 receivable into keyways 58 of shell 14, for stabilizing the housing's position within the shell upon assembly.

Shell 14 is shown to include a pair of integral board locks 60 for retention of the connector to a circuit board, as is known, and also a plurality of fingers 62 extending into a plug-receiving cavity 64 with free ends 66 of fingers 62 adapted to seat within recesses into outer surfaces of the mating connector upon mating to mechanically retain the connectors in a mated condition. Further, shell 14 is shown at forward end 68 to include panel-engaging flanges 70 when mounted in an electronic apparatus (not shown) within an input/output port to provide shielding around the cutout thereof. Additionally, shell 14 includes a pair of rearwardly extending ground fingers 72 having free ends engageable under spring bias with the outer surface of the shield of the mating connector (FIGS. 5 and 6) upon mating.

Switch contact 100 is seen in FIGS. 1 and 2 to include a body section 102, a contact section or leg 104 depending therefrom, and an elongate cantilever beam spring arm 106 extending from body section 102 at a right angle remote from leg 104. A connector-engageable portion 108 extends from a deflectable end of spring arm 106 at a right angle and is in an operative relationship therewith. Switch contact 100 is insertable into housing 12 along rear face 110, with body section 102 oriented axially to be received into a vertical slot 112

of the housing and including several barbs 114 for retention therein upon insertion. Spring arm 106 extends along rear face 110 transversely to the deflectable end, and connector-engageable portion 108 is oriented axially to be received into a channel 116 of housing 12 during assembly. Switch contact 100 is inserted into slot 112 to a controlled depth to assure that all portions of the spring arm remain spaced rearwardly of contacts 16; optionally slot 112 may include a stop surface to define the insertion depth.

Referring now to FIGS. 3 and 4, switch contact has been assembled to housing 12 along rear face 110. Leg 104 is seen to depend below mounting face 118 of connector 10 for electrical engagement with a circuit of a circuit board (not shown), alongside legs 36,38 of contacts 16,18. A contact-engaging section 120 is defined at the spring arm's deflectable end and is offset forwardly from the remainder of spring arm 106 to be engaged under spring bias against contact 18 at an upper end of its leg 38, while assuring that the remainder of the spring arm is spaced sufficiently from the rear face to be electrically isolated from contacts 16. Connector-engageable portion 108 extends forwardly into housing 12 within channel 116 and spaced from the remainder of contact 18. Channel 116 is sufficiently wide to define a clearance enabling connector-engaging portion to be moved rearwardly and also partially pivot by reason of the deflection of spring arm 106. Preferably portion 108 is offset vertically from body section 30 of contact 18 to assure nonengagement therewith at any position of deflection, so that channel 116 may be in communication with passageway 34 but is generally offset therefrom. It can be seen in FIG. 4 that portion 108 is preferably offset vertically from body section 30 and first portion 22 of contact 18. Leading end 124 of portion 108 is shown to extend forwardly of forwardly facing wall 126 of housing 12 for

engagement by a forwardmost portion of a mating connector, and is free to be urged rearwardly thereby to become disengaged from contact 18 upon full mating. FIG. 4 also illustrates the mating face of the connector. A planar forward portion 128 of housing 12 projects forwardly of wall 126, and defines a plurality of channels 130 within and along which extend first portions 20,22 of contacts 16,18, with first contact sections 24,26 defined on convex leading ends to protrude out of channels 130 and beyond surface 132 of housing portion 128 to be assuredly engaged by corresponding contacts of the mating connector.

In FIGS. 5 and 6, mating connector 200 is shown in fully mated relationship to connector 10. Plug portion 202 has been received into cavity 64 of connector 10 and coextends along forward housing portion 128 adjacent surface 132 thereof, for corresponding contacts 204 to electrically engage contacts 16,18 at their first contact sections 22,24. The forward portion of plug shell 206 has been received within cavity 64 and within shell 14 of connector 10 while correspondingly receiving forward housing portion 128 of housing 12 into cavity 208 defined by plug shell 206. Latch recesses 210 are defined into plug shell 206 and leading ends 66 of fingers 62 of shell 14 are seated therewithin to retain the connectors in mated relationship. Ground fingers 72 of shell 14 of connector 10 are in engagement with plug shell 206.

Upon full mating, leading end 212 of plug portion 202 has abutted leading end 124 of connector-engageable portion 108 of switch contact 100 of connector 10 and has urged it rearwardly. Concurrently, contact-engaging section 120 of spring arm 106 is moved rearwardly and out of engagement with contact 18 to break the previously existing electrical circuit sensed by a component of the circuit board (not shown) to which connector 10 is mounted. Preferably, at least contact-

engaging section 120 of switch contact 100, and the engaged surface of contact 18, are gold plated for assured electrical engagement for long-term in-service use. Connector 310 in FIGS. 7 and 8 is shown to be of the type having a housing 312 disposed within a shell 314 and containing a plurality of signal contacts 316,318 having first contact sections 320,322 arrayed across a mating face at a connector portion forwardly of housing wall 324 and within a plug-receiving cavity 326 of the connector. Contacts 316,318 also include second contact sections or board-connecting posts 328,330 depending from board-mounting face 332 of the connector, for receipt into through-holes of a circuit board (not shown) for connection to circuits of the board.

Shell 314 is shown to include board-mounting legs 334 also depending from board-mounting face 332 to secure the connector to the board. Shell 314 extends forwardly to a leading end and defines plug-receiving cavity 326 forwardly of vertical wall 324 enclosing the forward connector portion, and provides retention arms 336 having embossed leading ends 338 that seat within corresponding recesses into the outer surfaces of a mating plug connector (see FIGS. 5 and 6) upon mating to retain the connectors in mated relationship. Shell 314 also includes grounding arms 340 that extend rearwardly to free ends 342 that engage outer surfaces of the shell of the plug connector upon mating.

Housing 312 provides a contact support wall 344 that extends forwardly in plug-receiving cavity 326 and contains channels 346 within and along which first contact sections 320,322 of contacts 316,318 extend, with intermediate convex contact portions 348 protruding above the surface of support wall 344 to be engaged by complementary contacts of the plug connector. Free ends 350 of contacts 316,318 are trapped beneath undercuts 352 at leading ends of channels 346 for precise

positioning and protection, and are spring biased against the undercut upon assembly, all as is known. Body sections 354 provide barbs to engage side walls of passageways 356 for retaining the contacts in the housing.

A switch contact 370 (best shown in FIG. 9) is inserted into the housing and engages a selected signal contact 318 when the connector is in an unmated state, and becomes disengaged therefrom when in a mated state. Switch contact 370 includes a body section 372, contact or board-connecting section 374, spring arm 376 extending to a free or deflectable end at or near which is a forwardmost surface comprising a connector- engageable portion 378, and a contact-engaging section 380 located proximate the free end. Body section 372 includes a slot 382 having barbs 384 along opposed edges thereof to grip therebetween rib 358 in contact- receiving slot 360 of housing 312, best seen in FIGS. 11 and 12. Board-connecting section 374 is to be electrically connected to a circuit of the circuit board utilized to indicate whether or not a fully mated condition exists.

Contact-engaging section 380 is of limited length preferably extending laterally from a lower edge of spring arm 376 and is formed to extend arcuately rearwardly, defining a forwardly-facing bearing surface 386 for engagement with selected contact 318. The engagement surface of selected contact 318 is along transition section 362 somewhat steeply angled extending from body section 354 to intermediate section 348. For simplified manufacture, all contacts 316,318 are identical and thus all are shown to have transition sections 362.

Prior to loading of switch contact 370 into housing 312, spring arm 376 has been formed to extend from body section 372 at less of an angle, represented in FIG. 10 as 376a in phantom, so that upon loading, contact-

engaging section 380 will be spring loaded against transition section 362 of contact 318 as spring arm 376 is moved to a sharper angle more transverse, represented as 376b. The leading end of switch contact 370 comprising the connector-engageable portion 378, is so positioned in the plug-receiving cavity 326 as to be abutted by the forward end of the mating plug connector (not shown) and urged rearwardly thereby toward vertical housing wall 324 during final stages of connector mating when the plug connector is being inserted, and the deflected position of the spring arm of the switch contact is represented as 376c in phantom.

As shown in FIGS. 9 and 10, housing 312 includes clearance area 364 into vertical wall 324 providing clearance for spring arm 376 and tooling for loading the switch contact into the housing, where the tooling holds the spring arm in position 376b. Housing 312 also includes relief area 366 into vertical wall 324 for receipt of the spring arm thereinto when deflected. Contact-engaging section 380 extends laterally for a short distance from an edge of spring arm 376 to engage contact 318, with the remainder of spring arm 376 being spaced substantially from the other contacts 316 and also from selected contact 318 when deflected in position 376c for assured electrical isolation therefrom. Housing 312 further preferably includes relief areas 368 along side walls of channel 346 for selected contact 318 to assure freedom from any interfering engagement of housing 312 with contact- engaging section 380 when spring arm 376 is being moved into or out of its fully deflected position 376c.

Referring now especially to FIG. 13, during mating and unmating, bearing surface 386 wipes along portions of the surface of transition section 362, thus cleaning both surfaces of any corrosion layer. Preferably, both bearing surface 386 and the surface of transition section 362 are plated with gold to optimize the assured

electrical engagement therebetween and minimize corrosion buildup. In FIG. 13, the unmated state is illustrated, with the position of selected contact identified as contact 318a; the fully deflected position thereof is shown in phantom and identified as contact 318b. The preferred relatively sharp or steep angle of transition section 362 provides a more positively defined forwardmost location for the contact-engaging section 380 of the switch contact 370 even as the intermediate section 348 of selected contact 318b has been initially engaged and deflected toward support wall 344 and relatively completely into channel 346 by a mating contact during plug mating while still defining a surface engaged by contact section 380. The steep transition section 362 provides control over the location of the contact-engaging section 380, preventing the spring arm from inadvertently moving forwardly along intermediate section 348 when the plug connector has deflected contact 318 but prior to abutting leading end 378.

Similarly, when the plug connector is being withdrawn during unmating, the contact 318 remains deflected but the switch contact leading end is spring biased to move forwardly as the leading end of the plug connector retreats: steep transition section 362 permits only incremental forward movement of the contact-engaging section 380 until contact 318 resiles out of channel 344. Finally, the steep angle of transition 362, although it is not preferred to be vertical, still effectively creates a distinctly limited range of positions of the contact-engaging section 380 so that a distinct engaged/nonengaged relationship is established to indicate a fully mated as opposed to unmated or only partially mated relationship between the connectors.

The embodiments described hereinabove require minimal modification to a commercial connector, and no

modification to the shape of the contacts nor their spacing along the mating interface, nor any modification to the shell of the connector, nor any modification to the commercially available mating connector. The commercially available mating connector is sold by AMP Incorporated, Harrisburg, PA, USA, under the identification "Universal Serial Bus" plug connector having Part No. 95-8083-20. The previous connector to which modification has been made, is similarly sold as "Universal Serial Bus" receptacle connector having Part No. 787616, by AMP Incorporated.