US2897471A - High voltage connector - Google Patents

Description

July 28, 1959 D. R. DE TAR 2,397,471

HIGH VOLTAGE CONNECTOR Filed Jan. 30, 1956 1 1 T q /3 /Q #24271213 I Z5 Z6 ///X//// \\\1 Z7 7 y y//WY f /6 :l kaf/9 (/f i+1'.

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United States Patent O HIGH VOLTAGE CONNECTOR Donald R. De Tar, Stratford, Conn., assignor to Winchester Electronics, Incorporated, Norwalk, Conn., a corporation of Connecticut Application January 30, 1956, Serial No. 562,115 i 6 Claims. (Cl. 339-94) The present invention relates to an electrical connector and relates, more particularly, to an electrical connector for use at high voltages and high altitudes.

An object of the present invention is to provide an electrical connector which is capable of carrying high voltages at extremely high altitudes and in which the size and weight of the connector are kept at a minimum.

Another object of the invention is to provide an articulated high-voltage connector which will permit a small amount of relative movement between the plug and the receptacle, as will occur under conditions of severe vibration, without damage to the connector and without loss of voltage rating.

A further object of the invention is to provide a highvoltage connector in which the parts are of simple and inexpensive construction so that the connector may be made at low cost. In addition, the number and arrangement of the contacts used in the connector may be readily varied to meet various customer requirements.

Other objects and advantages of the invention will be apparent and best understood from the following description and the accompanying drawing in which:

Fig. l is a side view in vertical section of an assembled high voltage connector embodying the present invention shown on an enlarged scale;

Fig. 2 is a section view taken along the line 2-2 of Fig. l;

Fig. 3 is va section view taken along the line 3-3 of Fig. l;

Fig. 4 is a side view in vertical section of a part of the assembled connector shown in Fig. 1; and

Figs. 5 and 6 are graphical illustrations of the effect of changes in altitude on the breakdown voltage of an electrical connector and an air gap.

For use in air at an atmospheric pressure corresponding to sea level, satisfactory electrical connectors of small size may be provided for carrying electrical voltages up to several kilovolts as is commonly required for electronic equipment. Under such conditions, the voltage rating of such connectors may be increased by merely increasing the free air path between adjacent contacts in the connectors and the size of such connectors may be kept reasona-bly small by the use of telescoping barriers to provide a circuitous air path between the contacts.

However, with air under raried conditions as at the extremely low pressure encountered in present high altitude flight, electrical conditions change radically and it becomes impractical to increase the voltage rating of a connector by merely increasing the free air path between the contacts. Thus, a serious problem is encountered in providing a satisfactory high-voltage connector which is small in size and light in weight for aircraft or similar uses. Such conditions `are shown graphically in Figs. 5 and 6. In Fig. 5, the breakdown voltage in percent for an ordinary connector is plotted against altitude and from this it will be seen that the breakdown voltage at seventy thousand feet is only about 7% of the breakdown voltage at sea level. In other words, if the connector fails at 10,000 volts at sea level, it 4will fail at about 700 Volts at seventy thousand feet. As will be seen from Fig. 6, this condition cannot be satisfactorily overcome by increasing the spacing between the contacts.

In Fig. 6, breakdown voltages have been plotted against air gap distances for altitudes of zero and seventy thousand feet. It will be seen that the slope of these curves decreases as the breakdown voltage is increased and this effect becomesmuch more pronounced at high altitudes. Because of this, a high voltage connector for use at high `altitudes with free air paths between the contacts would be extremely large and heavy and therefore unsuited for most aircraft or similar `applications as a large number of connectors are generally required for such installations and their size and weight becomes an important factor.

In accordance with the present invention, it has been -found that a satisfactory high voltage electrical connector which will occupy a reasonably small space and be light in Weight may be provided for such use by interrupting the air path between the contacts with a solid dielectric material at one or more points. The construction of one form of connector embodying these principles is shown and described hereinafter.

Referring to Fig. l, there is an assembled connector which comprises -a receptacle 10 and a plug 11. The receptacle vand the plug each include a body portion 12 which may be molded from any suitable insulating material such as melamine resin. The molded body portions for the plug and the receptacle are cylindrical in shape but may be formed in any desired shape. The body portions may also be identical for economy in manufacture.

Each of the body portions has spaced bores 13 and 14 extending therethrough. Male contact members 15 are mounted in the bores in the plug body and female contact members 16 `are mounted in the receptacle body. Portions of the contact members are exposed at the mating `faces of the respective body portions so that when the plug and receptacle are brought into assembled relation, as shown in Fig. l, the exposed ends of the male contacts will engage with the exposed ends of the female contacts and make an electrical connection therewith. The other ends of the contacts also extend beyond the outer ends of the plug and receptacle bodies and are provided with the usual wiring terminals. The contacts are of conventional construction and may be held in place by C-rings `17 in the usual manner.

The mating faces of the body portions have enlarged openings 18 and 19 communicating, respectively, with the bores 13 and 14. Intermediate insulating members 20 of spool-like shape which may be made of nylon or other suitable material extend into the enlarged openings in the plug and receptacle bodies and surround the male and female contacts at their juncture points when the plug and receptacle are assembled. The spool-like members each have a bore extending therethrough and may be loosely attached to one of the contact members as by engagement of a shoulder 21 on the female contact with a shoulder 22 in the bore of the insulating member.

The intermediate insulating members have annular grooves 23 in their outer surfaces in which resilient rubber O-rings 24 surrounding the members are retained. The resilient rings 24 are under compression between the sides of the enlarged openings in the mating faces of the plug and receptacle and effect an air-tight seal between the body portions and the intermediate insulating members which interrupts the free air path that would otherwise exist between the exposed portions of adjacent contact members or other points to which there might be leakage.

In this arrangement, the intermediate insulating members have a limited movement or oat which compensates Y forslight rnisalignment of the twoconnector halves, Aand which also insures maintenance of an air-tight seal under conditions causing small relative motion between the plug andthe receptacle. f f 1 he outer-ends of the-plug'andrreceptacleaodylportions are zpirovide'd with round `bosses 2S through lwhihthe bores 13 and 14 extend. After-a connectionf'has 'been' made'to the terminal of acontact, one fof arubber sleeve 26 isstretched over 1the bossthroughlwhichithe'con# tact vextends and the other end-fof the rubber-sleeveis placed 'over the jacketofthe cable Z7 which-lis 'attached-to theflterminal :of the-contact. 'the fexposed-fteminiconnection to thefcoritact isthus enclosedin 4 arltgh'tlm'ahner which interrupts *the air path betweenthe terminal endsof adjz'tcent contacts vor-So'ther leakage ipoiltts. v It will be lunderstood that various changes fand modifi; cations -may'fbe made in the embodiment offtheiinvention illustrated and described herein withoutdepartingfromth'e scope of the invention as defined by the following claims. I claim: y

il. ylllrniniature type electrical #connector for-use athig'h voltages and at v'high altitudes which comprises 3a' pair Ior" bodies of insulating Imaterial `forming a`fplug" and a receptacle, i' said* connector lbodies having mating ffa'ces opposing spaced recesses 4formed Ain `mating faces, spaced contact members carried "by each ofthe connector bodies, said contact members having exposed bontact portions wlocated in the `spaced recesses 'in "the connector bodies, `the contact portions of the contact 'members carried by one of the "connector bodies entering into fengagement with the contact portions of the opposing-contact members carried by the other connector' body,- Ia separate member of insulating material surrounding'the-interengaged portions of each set of contact members and extending'into the opposing recesses in thematingffaces of the vconnector bodies, and means for forming `"an 'air-'tight seal between said separate-'members andeac'h 'ofthe 'connecto'r-bodies, said sealing means comprising'rnembers-o'f resilient insulating material loca-ted: between andengaging with the 'sides 'of the'recessesjin Veach o'fthe connector bodies andthe` separate insulating members. 2. ln a miniature type electrical connector -fort'xs'efat high voltages and at high altitudes, the combination which comprises a pair of connector bodies "oT insulating material `forming a plug and a'receptaclefsaidconnector bodies having mating faces with'opposed spaced recesses formed therein, aplurality ofspaced contacts carriedby eachV ofthe connector bodies, each of said contactshaving an exposed portion located in one ofthe spaced recesses in the respective connector bodies with the exposed portionsof'the'contacts carried by one of thefconnector bodies entering'into engagement 'with theexposed portions 4 of the contactscarr'ied by the 'other Yconnector body the matingfaces of the connector bodies are brought -into engagementwi'th Aeach other, ak separate member-vof insulating material surrounding the interen'gaged 'portions of each 'set of contacts and extending into theopposing recesses in the mating faces of the Vconnectorbodies, and resilient sealing means engaging with sai'dseparate members and surfaces of the connector `bodies defining 'the reasoman l cesses in the .mating Y:faces .thereof and forming van airtight seal therebetween whereby air-paths between exposed portions of the spaced contacts are interrupted.

3. In a miniature type electrical connector as defined in claim 2 wherein the resilient sealing means includes a ring of resilient material vextending around each end of t the separate insulating members.

4. A miniature type electrical connectorforuse at high voltages and at high .altitudes which .comprises a connector body formed from a'relatively rigid insulating Imaterial, said body having a plurality of spaced recesses in vone'face thereof, a plurality of contacts extending through said Y body in spaced "relation to each other, 'eachbf said conairtight seals between 'the 'separate insulating 'members and the connector 'body whereby the ir-fpathalongthe face of the connectorbody between the exposed petitions of the 'contacts is interrupted. y 5. miniature type electrical connector as delin'ed'i'n claim 2i whereinthe separate members 'of insulating ina# terial 'project beyond theface of the connector "body containing the recesses. Y

L6. A miniature 'type electrical connectorffor use 'at high voltages and at 'high attitudes which comprises a connectorbody'formed from a relatively rigid insulating frnaterial, said body having a'plurlity o'f spaced recesses in one'face thereof, a. plurality of contacts extending through said `body. in spaced relation to eac'h other, each of said contacts having an 4exposed portionprojecting into one of the recesses, `a separate member ormed vfrom a relatively rigid'insulatingmaterial surrounding the exposed portion of each of the contacts and extending into therecesses in which 'said exposed portion is located and a sealing ring of resilient material interposed'between each of the separate members and the surfaces of the connector body `forming the sides of said recesses, said rings being under compression and forming airtig'h't selsfbetween the separate insulating members andthe connector body whereby the air-path along the face of the connector body between the exposed :portions of `the contacts is interrupted.

References Cited inlth'e il'e'of' this rrpatent UNITEDLSTATES PATENTS.

Kirk Feb. `19, 11957

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