WO1996028864A1

WO1996028864A1 - High voltage low current connector interface

Info

Publication number: WO1996028864A1
Application number: PCT/US1995/016020
Authority: WO
Inventors: Christopher Warren Shelly; James David Hutchinson
Original assignee: The Whitaker Corporation
Priority date: 1995-03-10
Filing date: 1995-12-13
Publication date: 1996-09-19

Abstract

A high voltage electrical connector assembly having a first connector (10, 214) and a second connector (110, 212) with pin (14, 258) and socket (150, 244) terminals, with socket contact sections (26, 244) disposed in respective silos (28, 240) and pin contact sections (144, 256) extending forwardly within silo-receiving recesses (140, 250). A forward section (118, 266) of the second connector (110, 212) is of elastomeric material to enable sealing of the mating interface against voltage leakage upon compressive engagement with rigid material of the first housing (12, 252). A portion (154, 240) of elastomeric material extends closely along a base portion of the pin contact section (144, 256) at least upon connector mating, to be received into a portion-receiving recess (36, 250) of the rigid housing (12, 252), and in final stages of connector mating the recess bottom (38, 296) engages the portion leading end (164, 274) just prior to full mating and axially compresses the portion, with the elastomeric portion (154, 240) being deformed outwardly against side walls (40, 325) of the portion-receiving recess (36, 250) to define a discrete terminal site seal (166, 330).

Description

HIGH VOLTAGE LOW CURRENT CONNECTOR INTERFACE

The present invention relates to the field of electrical connectors and more particularly to matable connectors containing electrical contacts for high voltage low current interconnections.

Electrical connectors are frequently used to provide electrical connection in high voltage, low current energy systems, e.g., in systems carrying about 1000 volts up to about 50 Kv at one-half ampere or less, and the electrical transmission may be continuous or pulsed. Such connectors must operate with high reliability, often under severe environmental conditions. For example, connectors are frequently incorporated into high-voltage, electronic circuits located in hostile environments and must maintain peak performance within a broad temperature range and under diverse vaporous and gaseous conditions. In aircraft, such systems must having high reliability in a temperature range of from -55°C to +125°C and from sea level to 70,000 feet altitude, where ambient pressure is substantially lower than at sea level.

The primary problems with such high voltage applications are the discharge of voltage along a path from the connection to the environment, and the formation of corona (or voltage leakage) around the connection; both problems are aggravated under high altitude, extreme temperature conditions. Voltage discharge is a failure of the connector requiring connector replacement. Corona formation and voltage leakage commonly leads to degradation and possible breakdown of the dielectric insulation around the terminals and the conductors of the conductor wires, which commonly leads eventually to voltage discharge. To minimize corona formation and avoid voltage leakage and accompanying dielectric voltage breakdown, it is necessary that an assured airtight dielectric seal established about the terminals in their mated condition, and at the termination of the terminals with their respective conductors. In US-A-4,886,471, the socket terminal is terminated to a conductor wire and a respective plug housing is molded therearound of silicone rubber, and has a long axial recess extending axially thereinto from the forward face thereof to receive force-fittably thereinto the receptacle wall of the mating receptacle housing so that the silicone rubber plug wall forces practically all air from the cavity and establishes a tight grip along the inside and outside surfaces of the rigid receptacle wall; the tight air-free grip is sufficient to establish assured sealing around the mated contact interface and also adequate resistance to unintentional decoupling without other fastening means but permit intentional decoupling under sufficient axial force. It is desired to provide improved high voltage sealing in a matable electrical connector assembly having a single pair of mating terminals or a plurality of thereof.

It is desired to provide improved high voltage sealing in a matable electrical connector assembly to resist voltage leakage at above 15 kilovolts. SUMMARY OF THE INVENTION

It is an objective of the present invention to provide enhanced high voltage sealing at the mating interface by adapting the elastomeric structure immediately surrounding the contacts of one connector and the corresponding rigid structure immediately surrounding the complementary contacts of the other connector, such that the elastomeric material is selectively compressed or deformed to assure high voltage sealing immediately adjacent each mated contact pair upon full connector mating.

A high voltage electrical connector assembly has a first and second connectors with pin and socket terminals, with the socket terminals disposed in respective silos and the pin contact sections extending forwardly within silo-receiving recesses. A forward section of the second connector is of elastomeric material to enable sealing of the mating interface against voltage leakage upon compressive engagement with rigid material of the first housing. A portion of elastomeric material extends closely along a base portion of the pin contact section at least upon connector mating, to be received into a portion-receiving recess of the rigid housing, and in final stages of connector mating the recess bottom engages the portion leading end just prior to full mating and axially compresses the portion, with the elastomeric portion being deformed outwardly against side walls of the portion-receiving recess to define a discrete terminal site seal.

In a first embodiment, the first connector's housing is of substantially rigid dielectric material, with socket terminals retained within respective passageways therethrough. The second connector's housing includes a rearward housing section of rigid dielectric material including a transverse body section, and a forward housing section of elastomeric material such as silicone rubber forwardly of the rigid housing section and containing pin terminals; a silo-receiving recess open to the mating face surrounds each pin contact section. The elastomeric forward housing includes a short flange of frustoconical shape at the interior end of each silo-receiving recess surrounding the respective pin contact section and protruding forwardly a limited distance from the bottom thereof. The flange is engageable by the leading end of the respective silo of the first connector at final stages of connector mating, with the flange received into an enlarged flange-receiving recess of the silo just forwardly of the leading end of the socket contact section. The length of the flange is slightly longer than the length of the flange-receiving recess in the leading end of the silo, so that the flange becomes compressed longitudinally upon abutment with the bottom of the flange-receiving recess and radially expanded firmly against the inwardly facing surface of the flange- receiving recess to seal thereagainst. Concurrently, the inner surface of the silo-receiving recess coextends along the flange and is spaced radially therefrom to define a silo-receiving gap. The outer sidewall of the silo- receiving gap is incrementally greater in diameter than the outer diameter of the silo leading end, permitting expression of air away from the flange and the mated contact sections, and along the outer surface of the silo and rearwardly therealong.

In another aspect of the first embodiment, the side walls of the silo-receiving recesses include at least one annular embossment, and preferably a plurality of annular embossments spaced therealong, to engage under compression the side walls of the silos upon full entry thereinto upon full connector mating, with the annular embossments expanding around the silos. Preferably some of the recesses have their annular embossments defining a first arrangement axially offset from a second arrangement of annular embossments of others of the recesses that are generally adjacent thereto. In a second embodiment, the first connector contains pin terminals, and the second connector contains socket terminals. The connectors disclosed herein may take the form of inserts disposed within matable connector assemblies containing pin and socket terminals for conventional low voltage signal transmission and also coaxial terminals. The second connector includes a rearward housing section of rigid dielectric material with apertures therethrough corresponding to the socket terminals, and disposed in each of the apertures is an member of elastomeric material containing the respective socket terminal and extending rearwardly through the aperture. Each elastomeric member is shaped as a frustoconical elongate silo around the socket contact section of the socket terminal, with the leading end of the socket contact section recessed a selected distance from the silo leading end, and preferably spaced rearwardly from a silo leading end portion having a reduced inner diameter. The mating face of the second connector's housing defines frustoconical silo-receiving recesses within which the pin contact sections are exposed. The length of each silo is slightly longer than the length of the silo-receiving recess, so that the leading end portion of the silo becomes compressed longitudinally upon abutment with the bottom of the silo- receiving recess, and the silo radially expanded firmly against the inwardly facing surface of the silo-receiving recess to seal thereagainst. The air is progressively forced away from the pin and socket contact sections and is expressed essentially completely from the mating interface during final stages of connector mating.

It is an objective of the present invention to provide a matable electrical connector assembly for high voltage electrical transmission, that minimizes the formation of voltage leakage paths and corona.

It is another objective to provide a discrete terminal site seal, permitting use in a connector having a single terminal site or a plurality thereof, assuring sealing about each terminal upon full connector mating.

It is a further objective to provide a sealed mating interface around each mated terminal pair by generating substantial compression between elastomeric material and rigid material at substantially all surface-to-surface interfaces immediately about the terminal site.

It is yet another objective for such connector to provide for expression of air in a path away from the mating electrical terminals just prior to full connector mating, thus eliminating, or minimizing the amount of, trapped air along the mating interface and also locate any remaining incremental pockets of trapped air farther from the mated electrical terminals.

An embodiment of the present invention will now be described by way of example with reference to the accompanying drawings. FIGURE 1 is a longitudinal section view of the first and second connectors of one embodiment spaced from each other and containing the present invention;

FIGURES 2 and 3 are front elevation views of the first and second connectors of FIG. 1, respectively;

FIGURES 4 and 5 are enlarged partial section views of a socket terminal site of the first connector and a pin contact terminal site of the second connector of FIG. 1, respectively; FIGURES 6 to 8 are enlarged section views of the socket and pin terminal sites of FIGS. 4 and 5 during connector mating, with FIG. 6 partially mated, FIG. 7 almost fully mated and FIG. 8 fully mated and the terminal sites sealed; FIGURE 9 is an isometric view of the mating faces of matable electrical connectors of another embodiment containing inserts for high voltage low current electrical connections;

FIGURE 10 is a front view of a connector of FIG. 9 illustrating the location for an insert;

FIGURE 11 is an isometric view of the mating faces of the inserts of the connectors of FIG. 9, with one thereof containing elastomeric seals of the present invention;

FIGURE 12 is an isometric view of an elastomeric seal of FIG. 11;

FIGURES 13 and 14 are longitudinal section views of a high voltage terminal site, with FIG. 13 having the inserts and elastomeric member exploded and without terminals, and FIG. 14 being assembled with terminals and mated; and

FIGURES 15 to 17 are enlarged section views of the socket and pin terminal sites of FIGS. 13 and 14 during connector mating, with FIG. 15 partially mated, FIG. 16 almost fully mated and FIG. 17 fully mated and the terminal sites sealed. FIGS. 1 to 8 are used to illustrate a first embodiment of the present invention, and FIGS. 9 to 17 provide a second embodiment.

As seen in FIGS. 1 to 3, the matable electrical connector assembly of a first embodiment comprises a first connector 10 and a second connector 110. First connector 10 has a housing 12 of substantially rigid dielectric material and containing a plurality of socket terminals 14 terminated to respective conductor wires 16 and retained within respective passageways 18 extending from a wire exit face 20 to a mating face 22. Second connector 110 includes a housing 112 having a rearward housing section 114 having a transverse body section 116 of substantially rigid dielectric material, and a forward housing section 118 of elastomeric material affixed to a forwardly facing surface of transverse body section 116 and defining a mating face 120. Commonly the first and second connectors will include protective shells secured therearound (not shown) , with the housings comprising inserts secured therein, and with one of the shells including a coupling ring (not shown) for urging the connectors fully together to mate the terminals, as the coupling ring is rotated.

Forward housing section 118 includes a plurality of annular projections 122 extending rearwardly from a rearwardly facing surface of transverse body section 124 thereof and extending through respective apertures 126 through transverse body section 116 to a wire exit face 128. Pin terminals 130 to be terminated to respective conductor wires 132 are disposed within projections 122, in a manner that generates a seal 134 between the elastomeric material of the projections and the body sections of the terminals. Further, projections 122 are also in sealing engagement with side walls of apertures 126, all for effective sealing between wire exit face 128 and mating face 120. Transverse body section 116 of rigid rearward housing section 114 provides support for elastomeric forward housing section 118 and stabilizes the location of the several projections 122 and thus tends to stabilize the location and alignment of pin terminals 130 disposed therethrough. Bonding of the forward housing section with the rearward housing section and with the terminal body sections eliminates air between the elastomeric material the terminals and the rigid dielectric material of the rearward housing section.

Preferably the elastomeric material of the forward housing section is molded to the rearward housing section in a conventional insert molding (or overmolding) process, with previously molded rearward housing section primed and placed into the mold cavity and the terminals also primed and held in position within the mold cavity centered within the apertures through the transverse body section of the rearward housing section for the projections to become formed therearound and bonded thereto, assuring freedom from trapped air in the resulting part; the wire connecting sections of the terminals will extend rearwardly from the wire exit face to permit soldering to wire ends; after soldering the wire ends to the terminals, potting material is preferably deposited into the connector embedding the soldered terminations and the wire end portions. Regarding first connector 10, it is preferred that the body portions of the socket terminals be coated with epoxy to bond with the passageway sidewalls, and the terminals be secured within passageways 18 by force-fit, such as the forward portion of passageways 18 being slightly reduced to be in force-fit engagement with the leading end of the hood portion of the socket terminal surrounding and protecting the spring contact arms of the socket contact section (see FIG. 4) ; and for potting material to be deposited around the wire exits after termination of the wire ends with the rearward portions of the socket terminals.

Forward housing section 118 further includes a plurality of recesses 140 forwardly of projections 122 and aligned therewith, extending to mating face 120. Leading end portions 142 of pin contact sections 144 extend forwardly into recesses 140 to be exposed for receipt into leading ends 24 of corresponding socket contact sections 26 for mated electrical engagement therewith upon full mating of first and second connectors 10,110.

Referring to FIGS. 1 and 4, housing 12 of first connector 10 includes a plurality of silos 28 associated with respective socket terminals 14 extending forwardly to silo leading ends 30, with passageways 18 extending forwardly through respective silos 28 to silo leading ends 30. Socket terminals 14 are secured in passageways 18 such as in a force fit, such that leading ends 24 of socket contact sections 26 are recessed from silo leading ends 30, disposed rearwardly of lead-ins 32 that serve to assure centering of the leading end portions 142 of pin contact sections 144 during final stages of connector mating to assure appropriate mating and electrical engagement of the pin and socket terminals. Lead-ins 32 are defined by reduced diameter constrictions having lead- in surfaces angled to face radially inwardly and toward silo leading ends 30 with an innermost dimension grater than the outer dimension of a pin contact section 144.

Silos 28 of first connector 10 are slightly or gradually tapered extending to, or almost to, silo leading ends 30, thus defining frustoconical shapes. Referring to FIGS. 1 and 5, recesses 140 of second connector 110 are generally complementarily shaped, being tapered slightly overall from recess entrances 146 at mating face 120 to recess bottoms 148. Each recess 140 also includes at least one annular embossment 150 and preferably several annular embossments 150 about its inner surface 152, spaced axially therealong, each to be eventually engaged by the outer surface 34 of a respective silo 28 upon full mating of the first and second connectors.

In one aspect of the present invention, generally, adjacent ones of recesses 140 have their annular embossments 150 relatively staggered (except at the recess entrances) , all so that the local deformation of the elastomeric material of the forward housing section 118 is distributed axially throughout the material between the plurality of recesses. The staggering of annular embossments may involve selected ones of recesses 140 radially staggered from others thereof. The annular embossments of the radially outermost recesses 140A (referring to FIG. 3) and of the centermost recess 140C may be in a first arrangement of common first axial positions, while the annular embossments of the intermediate circular row of recesses 140B are in a second arrangement of common second axial positions axially offset from the annular embossments of the first arrangement. Thus upon full connector mating (as shown in FIG. 7) , all annular embossments 150 are compressed radially outwardly by the outer surfaces 34 of the respective silos 28, and the local deformation of the elastomeric material adjacent the outermost and centermost recesses 140A,140B is axially offset from the local deformation of the elastomeric material adjacent the intermediate row of recesses 140B.

With such offset, in a multi-terminal high voltage connector where the terminals are relatively closely spaced, upon compression of all the annular embossments, the elastomeric material is locally deformed at axially spaced locations from recess to recess, rather than all at the same axial locations, thereby distributing the compressive forces more evenly. Optimal sealing occurs when each embossment seals uniformly around the silo. Without axial staggering of the locations of the annular embossments of adjacent recesses, sealing pressure of the embossments against the side walls of the silos is increased at the point of closest proximity to the adjacent recess. Stresses are reduced in the elastomeric material during the mating cycle, as compared to large stresses that would occur with embossments located at the same axial location, thus reducing mating forces and enhancing embossment durability.

In another aspect of the present invention, and referring primarily to FIGS. 4 to 8, the silo leading ends 30 and recess bottoms 148 generally define concentrically interfitting pairs of axially extending flanges, with one thereof being of elastomeric material enabling compression for sealing against the surfaces of the rigid material of the other adjacent the terminal sites. A pressure seal is thus formed adjacent and axially coex ending along a portion of at least the pin contact section 144. Flange 154 extends forwardly from recess bottom 148, with the inner surface 152 of recess 140 coextending along outer flange surface 156 and spaced radially outwardly therefrom to define a silo-receiving gap 158. Flange 154 is generally concentric around the pin contact section 144 and preferably with an inwardly facing surface 160 spaced radially therefrom a slight distance, forwardly of a forward annular collar 162 of the terminal's body portion. Such flange definition is obtainable in the insert molding process through use of a cylindrical core pin surrounding the pin contact section and abutting the forward annular collar, with the core pin also serving to maintain the pin terminal in position and axially aligned during molding. A flange-receiving recess 36 is defined into silo leading end 30 forwardly of socket contact section leading end 24 and forwardly of lead-in 32. Gap 158 is adapted to receive thereinto silo leading end 30, while flange- receiving recess 36 receives flange 154 thereinto, upon full mating of the first and second connectors.

Preferably both flange 154 and flange-receiving recess 36 have slight complementary tapers. Also, preferably flange 154 is so dimensioned for forwardly facing surface 164 to abut against forwardly facing surface 38 of lead-in 32 prior to full connector mating, and for the elastomeric material of flange 154 to be longitudinally compressed, thereby being radially expanded, or deformed radially outwardly, to establish a pressure engagement between inner surface 40 of flange-receiving recess 36 and outer surface 156 of flange 154. It has been observed that flange 154 does not deform radially inwardly toward the terminal when compressed longitudinally. Referring specifically to FIG. 6, connectors 10,110 are partially mated together. Pin contact section leading end 142 has been received past lead-in 32 (after centering has been assured thereby) and into initial engagement with spring arms 42 within the socket's protective hood 44 and recessed from socket contact section leading end 24. Annular embossments 150 have initially engaged the adjacent portions of outer surface 34 of silo 28 and have become slightly compressed, still permitting air to be urged thereby. Silo leading end 30 has received the forward portion of flange 154 partially into flange- receiving recess 36.

Referring now to FIG. 7, the connectors are now almost fully mated. Silo leading end 30 just about fills gap 158, and forwardly facing surface 164 of flange 154 has abutted lead-in 32 which defines the bottom of the flange-receiving recess. Annular embossments 150 have entered into substantial engagement with silo outer surface 34 and have been compressed radially outwardly thereby.

In FIG. 8, the connectors are fully mated. Silo leading end 30 has been urged against recess bottom 148

(now shown in phantom) and pressed into the elastomeric material thereat. Flange 154 has been longitudinally compressed to become deformed or expanded radially outwardly tightly against inner recess surface 40 to define pressure seal 166 along a noticeable axial length adjacent the site of the mated electrical contacts 14,130. Air still trapped along pin contact section 144 within flange 154 is believed to provide pressure outwardly on flange 154 tending to enhance the compressive forces of pressure seal 166. For purposes of comparison, the original length of flange 154 is shown in phantom extending to forwardly facing surface 164. Annular embossments 150 have become greatly compressed to define a plurality of pressure seals axially along silo 28.

In the connector mating sequence depicted in FIGS. 6 to 8, the gradual progression from slight to substantial compression of the annular embossments permits expression of air therepast and outwardly from the mating interface during connector mating, as silo 28 is received progressively deeper into silo-receiving recess 140. Incremental pockets of air eventually remain trapped between the annular embossments and are shown exaggerated in FIGS. 6 to 8 for purposes of explanation, with the nominal inner diameter of the silo-receiving recesses preferably being incrementally larger than the outer diameter of the silos at any given axial location, to minimize difficulty in achieving full connector mating; the incremental amounts of air trapped between the strong pressure seals completely around the silos at the annular embossments are essentially innocuous. Pressure seal 166 and the strong pressure seals defined by greatly compressed annular embossments 150 provide an effectively sealed connector mating interface minimizing the existence of a possible voltage leakage path thereat.

Preferably the elastomeric material used for forward housing member 118 is a silicone rubber, such as SILASTIC 55U high tensile strength silicone rubber sold by The Dow Corning Company of Plymouth, Michigan. Dielectric material for housing 12 and rearward housing member 114 may be VECTRA A130 glass fiber reinforced copolyester liquid crystal polymer sold by Hoechst-Celanese of Chatham, New Jersey. The angle of taper of the silo is about 1.75°, and the complementary silo-receiving recess is preferably about 2.12°. The angle of taper of the flange is about 2.86° and that of the sidewalls of the flange- receiving recess is preferably about 6.71°. Also, preferably the distance traveled by the silo leading end beyond the nominal recess bottom is about 0.015 inches. The silo leading end may have an outer surface peripherally therearound that is tapered only sufficiently to facilitate withdrawal from the mold cavity upon molding, for an axial distance of about 0.126 inches. Flange height preferably is about 0.087 inches and the depth of the flange-receiving recess about 0.067 inches. It can be seen that the number of annular embossments may be varied from the several shown. Further axial staggering of the annular embossments may be accomplished. A pressure seal could also be formed with modified interfitting flanges to coextend along a portion of the socket contact section, such as where the elastomeric member defines a lange-receiving recess receiving a flange of the silo therewithin and is incrementally expanded thereby upon full connector mating. In a second embodiment of FIGS. 9 to 17, a cylindrical connector 210 is shown in FIG. 9 of the type having a receptacle connector 212 and a plug connector 214 matable therewith. Receptacle connector 212 is shown to be an assembly of a protective cylindrical shell 216 of durable material such as metal, a housing assembly 218 of dielectric material mounted within shell 216 and through which extend socket terminals 220 having socket contact sections 222 extending forwardly of mating face 224 into plug-receiving cavity 226 defined by a shroud 228 comprised of a forward portion of shell 216. Plug connector 214 is shown to be an assembly of a protective cylindrical shell 230 of durable material such as metal, a housing assembly 232 of dielectric material mounted within shell 230, and a plurality of pin contacts (not shown) . Plug connector 214 includes a plug portion 234 extending forwardly to a mating face 236, and the leading ends of the pin terminals are recessed from mating face 236 in respective passageways 238. During connector mating, socket contact sections 222 will enter passageways 238 and enter into electrical engagement with the pin contact sections of the pin terminals therewithin. Housing assemblies 218 and 232 preferably are comprised of forward and rearward housing sections secured within respective shells 216 and 230 by a pair of screws passing through adjacent transverse flange portions (not shown) thereof, internal to shells 216 and 230.

In the central region of mating face 224 of receptacle connector 212 is seen an array of (six) silos 240 extending forwardly therefrom within shroud 228 within each of which is disposed a socket contact section 242 of a socket terminal 244 (seen in FIGS. 14 to 16) . Central region 246 is better seen in FIG. 10. Correspondingly, in the central region 248 of mating face 236 of plug connector 214 is an array of (six) silo-receiving recesses 250 adapted to receive thereinto the silos 240 of receptacle connector 212 during connector mating.

Referring to FIG. 11, silo-receiving recesses 250 are defined by an insert 252 that is disposed within central region 248 of plug connector 214. Silos 240 are portions of an insert 254 that is disposed within central region 246 (FIG. 10) . Within each silo-receiving recess 250 is contained a pin contact section 256 of a pin terminal 258 (seen in FIGS. 14 to 16) .. Altogether, inserts 252 and 254 comprise a high voltage low current electrical connector that provides protection against undesirable voltage leakage and the generation of corona during transmission of high voltage low current signals. Insert 252 may also comprise a pair of three-position high voltage inserts nested together within central region 246; such arrangement allows the high voltage cables to be assembled in three-conductor cable harnesses each with a respective insert, facilitating repair and replacement. In FIGS. 11 and 13, insert 254 comprises a molded dielectric body 260 having a flange section 262 encircling it spaced from the leading end 264 of body 260 that becomes positioned between the forward and rearward housing sections in which is disposed a retention clip of appropriate configuration seated within a groove defined between the forward and rearward housing sections, with the retention clip containing arrays of locking lances engaging the flange section 262. Preferably the rearward housing section includes axial channels coextending along the insert from rearwardly thereof permitting insertion of a tool to disengage the locking lances of the retention clip from flange section 262 for removal of insert 254 during servicing and repair. Insert 252 similarly has such an encircling flange cooperable with plug connector housing assembly 232 and a retention clip thereof.

Silos 240 are portions of members 266 molded of elastomeric material such as silicone rubber, a material commonly used in high voltage connectors. Each member 266 is associated with a particular socket terminal 244 that is disposed along a passageway 268 thereof, with a socket contact section 242 thereof disposed along and within silo 240 such that leading end 272 is recessed from silo leading end 274 (FIGS. 14 to 17). Member 266 also includes a body portion 276, an annular embossment 278 spaced rearwardly of the base of the silo portion along body portion 276 and further includes a pair of small dimensioned embossments 280 proximate the rearward end thereof.

Referring now to FIG. 13, longitudinal section views of inserts 252 and 254 and of elastomeric member 266 reveal passageways thereof through which the socket and pin terminals will be disposed. In elastomeric member 266, a reduced diameter portion is defined along passageway 268 at internal annular embossment 284 to grip the socket terminal upon assembly. An annular flange 282 is shown placed at the base of the silo portion to extend along and against the adjacent portions of forward surface 264 of insert 254. Such a flange 282 effectively closes off the entrance to aperture 286 of insert 254 into which body portion 276 is inserted during assembly. Where a lead-in to silo-receiving recess 250 is not utilized to facilitate blind mating of the silos in the respective recesses, such a flange is especially useful to seal between facing surfaces 264 and 298 of inserts 252,254 upon full mating peripherally about each mated terminal pair at the base of the silos, providing enhanced sealing performance; overcompression of such a flange between surfaces 264,298 should be avoided to prevent damage to the elastomeric member and subsequent reduction in sealing effectiveness. In aperture 286 of insert 254, an annular groove 288 is seen proximate forward surface 264 of insert body 260 and is associated with annular embossment 278 of elastomeric member 266 acting as a seat therefor during assembly. Silo 240 is shown to include at its leading end 274 a reduced diameter passageway portion 290 to be disposed initially spaced forwardly of the leading end of the socket contact section prior to full connector mating, with an inner diameter selected to be just large enough for receipt of a mating pin contact section thereinto to become electrically engaged with the socket contact section. Silo-receiving recess 250 is shown to be an enlarged diameter forward portion of passageway 292, with a reduced diameter portion 294 thereof creating a forwardly facing surface 296 defining the bottom of the silo-receiving recess. The depth of silo-receiving recess 250 is selected to be less than the length of silo 240 to be eventually received thereinto and longitudinally compressed thereby when connectors 212,214 become fully mated and portions of forward surface 298 of insert 252 are adjacent forward surface 264 of insert 254 at the base of silo 240. An enlarged passageway portion 300 rearwardly of reduced diameter portion 294 will receive therealong a body portion of a pin terminal. In FIG. 14 a pin terminal 258 has been disposed in and along the passageway of insert 252 with body portion 302 disposed in enlarged passageway portion 300 and a rearward termination section 304 terminated to a conductor of a respective high voltage cable 306 such as by crimping. Preferably the pin terminal and adjacent portions of the conductor are coated with a silicone rubber adhesive prior to insertion, to establish a bond for securing in the passageway; silicone rubber RTV adhesive No. 744 by Dow Corning may be used, and the terminal should be held carefully centered within the slightly larger passageway until adhesive curing occurs. Also, a length of heat recoverable tubing 308 is preferably utilized to surround and seal the tubular flange 310 extending rearwardly from insert 252 as well as adjacent portions of the high voltage cable 306. Elastomeric member 266 has been assembled within aperture 286 of insert 254 by interference fit, with annular embossment 278 seated within annular groove 288. A socket terminal 244 has been disposed in passageway 268 of elastomeric member 266 and through aperture 286 of insert 254, with body portion 312 gripped tightly at annular embossment 284 which is radially expanded upon terminal insertion. A rearward termination section 314 of socket terminal 244 is terminated to a conductor of a respective high voltage cable 316, such as by crimping. Preferably socket terminal 244 includes an annular collar 318 adapted to abut a rearwardly facing surface 320 along a rearward aperture portion 322 of insert 254 to serve as a positive stop during insertion of socket terminal 244 aperture portion 332 after being crimped to the cable conductor. A length of heat recoverable tubing 308 is preferably used to seal the tubular flange 334 extending from insert 254 and adjacent portions of high voltage cable 316. Each of the lengths of heat recoverable tubing may utilize sealant preforms for bonding to the annular flange and cable insulation upon heating of the lengths of heat recoverable tubing to reduce the tubing diameter to conform to the encased surfaces.

The present invention will now be more fully described with respect to FIGS. 15 to 17. In FIG. 15, connectors 212 and 214 are partially mated, and it can be seen that leading end 272 of socket contact section 270 is spaced rearwardly a distance from reduced diameter passageway portion 290 adjacent silo leading end 274, with a substantial portion of pin contact section 256 having entered socket contact section 270 to be electrically engaged with spring arms 320 within hood 322. Silo leading end 274 is shown in abutment with bottom 296 of silo-receiving recess 250 of insert 252. Forward surface 298 of insert 252 is shown spaced from forward surface 264 of insert 254. Silo leading end 274 is seen to have an outer diameter no greater than the inner diameter of silo- receiving recess 250 adjacent recess bottom 296. The angle of taper of the silo is seen to be just less than the angle of taper of the silo-receiving recess so that a slight annular gap exists at this point between silo 240 and silo-receiving recess 250 spaced from silo leading end 274.

Referring to FIG. 16, connectors 212 and 214 are almost fully mated. Forward surfaces 298 and 264 of the inserts are now close together. Silo 240 is now undergoing longitudinal compression as a result of connectors 212 and 214 continuing to be urged toward each other after silo leading end 274 has abutted recess bottom 296. The inner surface 324 of silo 240 is not bonded to the outer surface of socket contact section 242, so that as silo 240 undergoes longitudinal compression it is not hindered by a bond or by significant frictional force with the socket contact section. Consequently, socket contact leading end 272 is seen to move relatively forwardly along passageway 268 toward reduced diameter portion 290 thereof at silo leading end 274. It is also seen that silo 240 begins to be deformed or expanded radially outwardly for outer surface 326 thereof to be engaged with and compressed against inner surface 328 of silo-receiving recess 250, beginning at silo leading end 274 and progressing rearwardly along the silo because of the shape of the frustoconical gap between frustoconical surfaces 326 and 328.

In FIG. 17, connectors 212,214 are fully mated. Forward surfaces 298,264 of the inserts have been moved adjacent each other. For purposes of comparison, the original length of silo 240 is shown in phantom extending to silo leading end 274. Preferably no gap remains between socket contact leading end 272 and reduced diameter passageway portion 290. Outer surface 326 is seen to have become pressed against inner surface 328 of silo-receiving recess 250 along the length of silo 240, thus establishing an assured compression seal 330 of the elastomeric material of the silo and the rigid material of insert 252. Additionally, the elastomeric material of silo 240 next to flange 282 has been radially expanded at the tapered lead-in entrance to silo-receiving recess 250. Further, radial expansion occurs at the entrance to aperture 86 forwardly of annular embossment 278, at annular embossment itself to press it more firmly into annular groove 288, and at base portion 276, all as elastomeric member 266 is longitudinally compressed against the bottom of aperture 286. Compression seal 330 provides an effective seal of substantial axial length about and adjacent its respective mated pair of electrical contacts minimizing the development of a possible voltage leakage path thereat. With each such mated pair of contacts of the high voltage portion of the connectors having assured seals adjacent thereto, the mating interface of the high voltage portion of the mated connectors is effectively sealed against voltage leakage and corona. As the compression of outer silo surface 326 against inner recess surface 328 progresses from silo leading end 274 rearwardly along the outer silo surface, air is effectively expressed away from the mating contact sections and outwardly of the mating interface prior to full mating as in FIGS. 14 and 17.

The inner diameter of passageway 268 of the silo portion of elastomeric member 266 is preferably incrementally greater than the outer diameter of socket contact section 242 to permit movement of the silo inner surface therealong with only modest friction as silo 240 undergoes compression. The outer diameter of silo 240 is preferably incrementally less than the inner diameter of the silo-receiving recess 250 at corresponding axial locations, except at silo leading end 274 and recess bottom 296 where the diameter of silo leading end 274 is no larger than the diameter at recess bottom 296. The angle of taper of the silo is preferably just less than the angle of taper of the sidewalls of the silo-receiving recess 250. It is believed that air trapped within the silo and adjacent (or forwardly of) the pin and socket contacts pressurizes the elastomeric material of the silo to assist in radial expansion to press the material more tightly against the inner surfaces of the silo-receiving recess.

Preferably the elastomeric material used for elastomeric member 266 is a silicone rubber, such as SILASTIC 55U high tensile strength silicone rubber sold by The Dow Corning Company of Plymouth, Michigan. Dielectric material for inserts 252 and 254 may be polyetherether ketone (PEEK) such as POLYPENCO 450G sold by Polypenco, Ltd. of Hertfordshire, England. The angle of taper of the silo may be about 0.72°, and the angle of taper of the complementary silo-receiving recess may be about 1.31°.

The space between socket contact leading end and the reduced diameter passageway portion at the silo leading end is initially about 0.050 inches at assembly, prior to connector mating. Also, where no flange 282 is used, preferably the height of the silo is about 0.10 inches longer than the depth of the silo-receiving recess, and the leading end portion 290 of the elastomeric member's silo portion is compressed about 0.050 inches. For versions where flange 282 is used but no lead-in is formed at the entrance to silo-receiving recess 250, care should be taken to engage but not overcompress such flange 282, and less longitudinal compression of silo 240 is believed necessary to obtain effective sealing since the flange abuts and seals against forward surfaces of both inserts completely about the entrance to the silo-receiving recess, and the height of the silo therefore need be only about 0.050 inches longer than the depth of the silo- receiving recess. Providing an elastomeric member having a base portion length slightly longer from the rearward end to the annular embossment than the length of the aperture between the aperture bottom surface and the annular groove, allows compression of the member's base portion at assembly thereby radially expanded the base portion against the aperture sidewalls before connector mating and serves to enhance the sealing thereat.

It may be desirable to provide elastomeric members that have no annular flange about their base portions; this would enable closer spacing of adjacent terminal sites for higher density. A variation of the present invention could utilize elastomeric portions molded about individual terminal sites, or an integral elastomeric forward housing portion defining all terminal sites instead of discrete members therefor. It can be seen that a high voltage connector utilizing the present invention can have an effectively sealed mating interface with only one mating pair of electrical terminals, as well as with a plurality thereof. Also a hybrid electrical connector may have a high voltage low current transmission portion in addition to conventional low voltage signal transmission portion, by utilizing an insert having the present invention therein. Other variations and modifications may be made that are within the spirit of the invention and the scope of the claims.

Other variations and modifications may be adopted that are within the spirit of the invention and the scope of the claims.

Claims

WHAT IS CLAIMED IS;

1. An electrical connector assembly suitable for high voltage low current transmission, of the type wherein a first connector (10,214) includes a housing (12,252) of rigid dielectric material having a first mating face (22,236), said rigid housing (12,252) including at least one first terminal (14,258) disposed therethrough extending to a first contact section (26,256) exposed along said first mating face (22,236) for electrical engagement, a second connector (110,212) includes a housing (112) including at least one second terminal

(130,244) disposed therethrough extending to a second contact section (144,242) exposed along a second mating face (120,224) for electrical engagement, and further including a forward section (118,266) of elastomeric material along each said second contact section (144,242) and therebeyond, and ones of said first and second contact sections being pin contact sections (144,256) and others thereof being socket contact sections (26,240) complementary with and matable with respective said pin contact sections upon connector mating, characterized in that: said elastomeric forward section (118,266) provides a portion (154,240) of elastomeric material extending to a leading end (164,274) along and only incrementally spaced from a base portion of each said at least one pin contact section (144,256) at least upon connector mating, and said rigid housing (12,252) providing a portion- receiving recess (36,250) along each said pin contact base portion at least upon connector mating, adapted to receive thereinto said portion (154,240) of elastomeric material during connector mating and further providing a recess bottom (38,296) associated with said portion leading end

(164,274) ; and said connectors are adapted such that in final stages of connector mating said recess bottom (38,296) engages said portion leading end (164,274) just prior to full mating, and thereafter axially compresses said portion such that said portion is deformed outwardly against side walls (40,328) of said portion-receiving recess (36,250) to define a discrete terminal site seal (166,330) adjacent and along at least said pin contact base section of each mated terminal pair (14,130;258,244) .

2. The electrical connector assembly of claim 1, wherein each said at least one first terminal is a socket terminal (14) with said socket contact section (26) disposed within a respective forwardly-extending silo (28) to a socket contact leading end (24) recessed within a leading end (30) of said silo (38) ; said at least one second terminal is a pin terminal (130) , and said second connector elastomeric forward section (118) includes a silo-receiving recess (140) extending rearwardly from said second mating face (120) complementary with each said silo (28) ; each said silo (28) defines an outer surface (34) and each said silo-receiving recess (140) defines an inner surface (152) dimensioned for sealing engagement therewith upon full connector mating; and said elastomeric material portion is a flange (154) extending forwardly from a bottom (148) of each said silo- receiving recess (140) , said flange (154) having an outwardly facing surface (156) radially spaced inwardly from a coextending portion of said inside surface of said silo-receiving recess (140) to define a gap (158) therebetween, said flange (154) having an inwardly facing surface at least not bonded to said pin contact section (144) therewithin, and each said portion-receiving recess of said first connector (10) is a flange-receiving recess (36) into said leading end (30) of a said silo (28) complementary with a respective said flange (154) to receive said flange thereinto upon full connector mating for engagement between the outer surface (156) of said flange and an inner surface (40) of said flange-receiving recess under pressure at least upon full receipt into said flange-receiving recess (36) defining a seal (166) adjacent and axially coextending along a portion of at least said pin contact section (144) .

3. A high voltage connector assembly as set forth in claim 2 wherein said housing (112) of said second connector (110) includes a rearward housing section (114) of rigid dielectric material having a transverse body section (116) adjacent and rearwardly of a transverse body section of said elastomeric forward section (118) , and said elastomeric forward section includes a plurality of projections (122) surrounding respective said pin terminals (130) therethrough, with said projections (122) extending rearwardly through respective apertures (126) of said transverse body section (116) of said rearward housing section (114) and sealingly engaged with said apertures and with respective said pin terminals (130) .

4. A high voltage connector assembly as set forth in claim 2 wherein said inner surface (140) of each said flange-receiving recess (36) has a gradual taper and said outer surface of each said flange (154) has a complementary taper.

5. A high voltage connector assembly as set forth in claim 2 wherein each said silo (28) includes a reduced diameter constriction defining a lead-in (32) along a passageway (18) therethrough proximate said leading end (30) thereof just forwardly of said socket contact leading end (24) , and having a lead-in surface with an inner dimension greater than an outer dimension of a said pin contact section (144) for assuring the centering of a respective said pin contact leading end (142) prior to electrical engagement with said socket contact section

(26) , and said flange-receiving recess (36) is disposed between said silo leading end (30) and said lead-in (32) .

6. A high voltage connector assembly as set forth in claim 2 wherein selected ones of said silo-receiving recesses (140) each include at least one annular embossment (150) along said inner surface (152) thereof, said annular embossments of said selected ones (140A) of said recesses being all at a common first axial location defining a first arrangement, and selected others (140B) of said silo-receiving recesses generally alternating with said selected ones (140A) thereof across said second mating face (120) and each including at least one annular embossment (150) along said inner surface thereof, said annular embossments (150) of said selected others (140B) of said recesses being all at a common second axial location defining a second arrangement axially staggered from said first arrangement, whereby said annular embossments (150) of said first arrangement deform at an axial location staggered from said annular embossments (150) of said second arrangement, and when the locations of said selected ones (140A) and said selected others (140B) of said silo-receiving recesses are closely spaced across said second mating face

(120) , deformation of said elastomeric material of said forward section (118) is more evenly distributed for improved sealing of the mating interface of the connectors upon full mating thereof.

7. An electrical connector assembly as set forth in claim 1, wherein each said at least one second terminal is a socket terminal (244) with a socket contact section

(242) disposed within a respective forwardly-extending silo (240) of said elastomeric forward section (266) to a socket contact leading end (272) , with said socket contact section (242) not bonded to adjacent surfaces of said elastomeric forward section (266) ; each said first terminal is a pin terminal (258) and each said portion-receiving recess of said first connector housing (218) is a silo-receiving recess (250) extending rearwardly from said first mating face complementary with each said silo (240) ; each said silo (240) defines an outer surface (326) and each said silo-receiving recess (250) defines an inner surface (328) dimensioned for sealing engagement therewith upon full connector mating, and said inner surface (328) of each said silo-receiving recess (250) has a gradual taper and said outer surface (326) of each said silo (240) has a complementary taper; and each said silo (240) extends forwardly of said second mating face (224) a first selected distance, and said recess bottom (296) of each said silo-receiving recess

(250) is spaced a second selected distance from said first mating face (236) , all such that said silo leading end

(274) abuts said recess bottom (296) prior to full connector mating and is longitudinally compressed upon complete connector mating and is radially expanded for said outer surface (326) of said silo (240) to be compressed tightly against said inner surface (328) of said silo-receiving recess (250) upon full connector mating.

8. A high voltage connector assembly as set forth in claim 7 wherein said adjacent surfaces (324) of said elastomeric forward section (266) are incrementally spaced from outer surfaces of said socket contact section (242) therewithin, and said adjacent surfaces of said elastomeric portion includes an annular constriction (284) dimensioned to grippingly engage an outer surface of a body portion (312) of a said socket terminal (244) inserted into and along said passageway for sealing thereagainst.

9. A high voltage connector assembly as set forth in claim 7 wherein a leading end portion adjacent said silo leading end (274) extends forwardly beyond said socket contact leading end (272) a third selected distance.

10. A high voltage connector assembly as set forth in claim 9 wherein a passageway portion (290) through said leading end portion is less in diameter than an outer diameter of said socket contact leading end (272) .

11. A high voltage connector assembly as set forth in claim 7 wherein a rigid portion (254) of said second connector housing is disposed rearwardly of each said elastomeric portion (240) providing a support assisting in longitudinal compression of said silo (240) upon full connector mating.

12. A high voltage connector assembly as set forth in claim 7 wherein said housing of said second connector (212) includes a housing section (254) of rigid dielectric material having a transverse body section including apertures (286) extending therethrough, and said silos

(240) are discrete members (266) having body portions

(276) adjoining said silos (240) , said body portions (276) being inserted into and secured in respective said apertures (286) in sealing engagement with side wall surfaces of said apertures (286) and in a manner preventing axial movement with respect thereto during connector mating and unmating.

13. A high voltage connector assembly as set forth in claim 12 wherein said elastomeric member (266) includes an annular flange (282) surrounding a base portion of said silo (240) and extending laterally along a forward surface (298) of said housing section (252) of said first connector (214) , said annular flange (282) being larger in diameter than an entrance (250) to a respective said aperture of said housing section (252) , and said housing section (252) of said first connector (214) and said housing (254) of said second connector (212) are adapted to be moved together at full mating thereof such that an adjacent portion of a forward surface (264) of said rigid housing section (254) of said second connector (212) at least abuts said annular flange (282) without overcompression thereof, and said elastomeric member (266) includes an annular embossment (278) therearound proximate a base of said silo (240) positioned axially to be disposed within a respective said aperture (286) of said second connector rigid housing section (254) and seated within an annular groove (288) of said aperture (286) in interference fit to stabilize the axial location of said elastomeric member (266) with respect to said aperture and enhance a sealing engagement between said elastomeric member (266) and said rigid housing section (254) .