IL33707A - Electrical connectors - Google Patents

Description

Blectrioal oonneotore THE BUN R-RAMO CORPORATION C: 31974 This invention relates to electrical connectors and more particularly to electric connectors which are rugged in construction and highly reliable in operation under severe environmental conditions, which have a long operating life and which are readi-ly serviceable.

The invention was evolved with the general object of providing connectors suitable for use in aircraft, especially supersonic aircraft. In such applications, reliability is extremely important and environmental conditions are severe, particularly with regard to extremes in temperatures, shocks and vibrations and exposure to fuels, oils, solids and other fluids used in aircraft. It will be understood, of course, that although the connectors of this invention were designed for such applications, the principles and features of the invention are not limited thereto and may be used in various other applications.

In general, connectors of the type to which this invention, relate includes- pairs of mating electrical contacts supported in aligned passages in dielectric members which are supported within hollow shells adapted to be secured together to bring the mating ends of the contacts together, the opposite ends of the contacts being electricall connected to the ends of wire conductors. One difficulty with connectors of the prior art arises with regard to the provision of seals between the dielectric members for the purpose of preventing entry of fluids into the space around the electrical contacts and to prevent failure of the connectors and other adverse results, It is not possible to obtain proper sealing with ceramics or other hard dielectric materials and elastomeric dielectrics or elastomeric seals bonded to dielectric members of ceramic materi- have als or the like, kav*t¾g been proposed but severe difficulties have been encountered with regard to swelling and deterioration rienced with regard to servicing of prior art connectors* Usually, the failure of one contact in a connertor has required that the entire connector he scrapped.

According to the present invention an electrical connector comprises a pair of dielectric members, a pair of hollow shells supporting the pair of dielectric members therewlthln and arranged to be secured togethe to hold end surfaces of the dielectric members together in pressure engagement* the pair of dielectric members each having at least one passage therethrough, the passages being aligned in use, and contacts supported in the passages and adapted to be brought into mating electrical contact when the end surfaces are brought together in pressure engagement, the con iguration of the end surfaces and the characteristics of the material of the dielectric members bein such as to provide a fluid tight seal between the end surfaces whilst providing firm support for the contact, the end surfaces including tin integral neck about one end of a passage of each pair of aligned passages adapted to enter and be compresslvely de ormed by an end portion of the other passage, the end surfaces of the pair of dielectric members including planar portions of substantial areas in surrounding relatio to the passages, the planar portions being irmly engaged when the shells are secured together to prevent the formatio of fluid-entrapping pockets.

A feature of an embodiment of the Invention relates to a "monodlelectric" construction in which each one of a pair of contact-supporting dielectric members is i the form of a single homogeneous member and in which reliable sealing is achieved without the use of separate sealing members bonded to or otherwise associated with the dielectric member, ibis feature makes possible a simplified and economical construction. It also makes it possible to eliminate the use of elastomers in the connector and eliminates the problems encountered with the use of elastomers.

In accordance with this invention, a pair of dielectric members have end surfaces which are held together in pressure engagement when supporting shells are secured together and the configuration of the end surfaces and the characteristics of the material of the dielectric members are such as to provide a good fluid seal between the end faces of the dielectric- members while at the same time providin firm mechanical support for contacts supported In said passages.

In one embodiment of the invention, each of the dielectric members is of a substantially homogeneous semihard material,, i.e. a material having an elasticity which Is less than that o elastomers while being greater tha that of ceramic materials, examples of preferred semi^hard materials being set forth hereinafter!.

I another embodiment of the invention, the end surfaces of the dielectric members include planar portions of substantial areas in surrounding relation to the contact passages, such planar portions being firmly engaged when the shells are secured together and being operative to prevent the formation of fluid-entrapping pockets so as to prevent corona discharges.

"The invention will now he described further by way of example, with reference to the accompanying drawings, In which: lieUHE 1 is a side elevational view, partly in cross-section, illustrating a eonnector constructed in accordance with the principles of this invention; FIGURE 2 is a end view of a receptacle portion of the connecto of FIGURE 1, showing the location o keyways and contacts; FIGURE 3 Is a cross-sectional view on an enlarged scale, showing in detail the relationship of portions of mating surfaces of dielectric members be ore engagement thereof FIG¾RB 4 Is a cross-sectional view on an enlarged scale, similar to FICiOHB 3 bu showing the surfaces in initial engagement.

!PICUHE 5 is a croBS-sectlonal view taken substantially along line V-V of FI&UEB 1, on an enlarged scale and showing the mating surfaces of the dielectric members in pressure engagemen and also showin the construction and operation of contac retention members; and FIGURE 6 is a cross-sectional view similar to a portion of FIGURE 5 , and showing one method of removal of contacts.

Reference numeral 10 generally designates a connector constructed according to the principles of this invention. The illustrated connector 10 comprises four pairs of mating electrical contacts, one pair of contacts 11 and 12 being shown connected to the ends of wires 13 and 14 in the cross-sectional portion of FIGURE 1 . It will be understood that the principles of the invention may be applied to connectors arranged to connect only a single pair of wires or any desired number of pairs of wires and that the wires may be enclosed within suitable shields of casings to form cables. For instance, a one inch diameter insert 17 18 (such as & or -3 · will accept nineteen size twenty mating contacts-. .

Contacts 11 and 12 are supported in aligned passages 15 and 1β in a pair of dielectric members 17 and 18 which are supported within a pair of hollo shells 19 and 20 , respectively referred to hereinafter as plug and receptacle shells. The plug shell 19 is adapted to be secured to the receptacle shell 20 by means of a coupling ring 21 connected to shell 19 through a spring arrangement described hereinafter and having an internally threaded portion 23 engaging an externally threaded portion 24 of the receptacle shell 20 . The plug and receptacle shells 19 and 20 are also provided with externally threaded portions 25 and 26 on which cable connectors may be threaded or on which grommet-carrying nuts may be threaded.

In assembly of the conneotor 10 , a portion 28 of the plug shell 19 is inserted part way within the receptacle shell 20 and is rotated, if necessary, until a master key 29 > projecting radi-ally outwardly from an intermediate point of the portion 28 is properly aligned with an axially extending keyway 30 formed in -to interengage the threads of the portions 23 and 24 after which the coupling ring 21 is turned to fully interengage the contacts 11 and 12 to provide a seal between the dielectric members 17 and 18 as hereinafter described.

As shown in FIGURE 2, four additional polarizing keyways 31 - 34 are preferably provided in the receptacle shell 20 with corresponding keys being formed in the plug shell 19 < Preferably, the master keyway 30 is wider than the additional keyways 31-34 as illustrated. Such additional keys and keyways may be arranged in one of a number of selected patterns to permit the connection of only those plug and receptacle shells having the proper pattern. Preferably, the angular relationship of the keyways 31-3^ are changed with respect to the master keyway 30 which has a fixed position relative to the contacts. By way of example, the angles in degrees from the centerline of the master keyway 30 to the centerlines of the keyways 31 -3^ measured in a counter-clockwise direction as illustrated may be 62 , 1 5, 180 and 280 in one arrangement as illustrated, 79 , 153 , 197 and 272 in a second arrangement, 135 , 170 , 200 and 310 in a third arrangement, 49, 169, 200 and 244 in a fourth arrangement, 66, l40, 200 and 257 in a fifth arrangement, and 80, 142, 196 and 293 in a sixth arrangement .

As also shown in FIGURE 2, the receptacle shell 20 may be formed with a radially projecting integral plate portion 36 having a generally square peripheral shape and formed with holes for. mounting on a panel.

To hoi/ d the dielectric members 17 and 18 within the plug and receptacle shells 19 and 20, they are formed with enlarged diameter portions 37 and 38 defining shoulders which are disposed be- tween shoulders 39 and 40 and retaining rings 41 and 42 on the inside of the shells 19 and 20. The portions 37 and 38 may be rotation of the dielectric members 17 and 18 relative to the shells 19 and 20.

A seal 44 is provided between the plug and receptacle shells 1 and 20 which is disposed in an annular recess 45 in the inner surface of the receptacle shell 20 spaced a short distance from the forward end of the plug shell 19 when the connector is assembled* The seal 44 comprises an annular member 46 of resilient material, preferably material known under the trade name "Teflon", which is of ϋ-shaped cross-section to define inner and outer walls. Disposed within the member 46 is an annular tubular member 4 preferably of metal and preferably of elliptical cross-section which serves to hold the inner and outer walls of member 44. in pressure sealing engagement with the outer cylindrical surface of the shell 19 and the inne cylindrical surface of the shell 20.

An additional seal is provided between end surf ces 49 and 50 of the dielec ric members 17 and 18 and according to an important feature, this seal is obtained with the "monodielectrie" construction in which each of the dielectric members 17 and 18 is a single homogeneous member, reliable sealing being obtained without the use of separate sealing members bonded to or otherwise associated with the dielectric members 17 and 18. In accordance with this feature, the surfaces 49 and 50 are held together in pressure engagement when the connector is assembled and the configuration o the en surfaces 49 and 50 and the characteristics of the dielectric material are such as t provide a fluid-tight seal between the end surfaces, while the contacts are firmly supported in the members 17 and 18.

Bach of the dielectric members is of a substantially By way of example, the material of the dielectric members 17 and 18 has a modulus of elasticity on the order of 300,000 pounds per square inch, i.e. from 30,000 to 3*000,000 pounds per square inch, preferably in a range of from 250,000 to 350,000 pounds per square inch. A material which is particularly suitable is a polymer manufactured by the 3M Company and identified as "Polymer 3βθ" or "P-36O" . This material and mechanical, electrical, thermal and other properites . thereof are described in a paper presented by Morneau and Bringer of the 3 Company at a conference of the Society of Plastics Engineers on "Stability of Polymers", at Washington, D.C., September 7-8, 1967. In general, this material is useful over a temperature range of from minus 400 degrees P. to plus 500 degrees F., has good long term resistance to oxidative degradation and maintains useful structural strength up to 500 degrees F., and it has very good dielectric and other electrical properties. The basic polymer structure consists of phenyl and biphenyl units linked by oxygen and sulfone groups. The non-aliphatic character of this structure is responsible for its resistance to oxidative attack at high temperatures while its aromatic nature contributes to strength at high temperature. The flexural modulus of elasticity of the material varies from about 400,000 pounds per square inch at about 70 degrees F. down to about 250,000 pounds per square inch at 500 degrees F. and the tensile modulus and compressive modulus are comparable.

The polymer 360 material is particularly suitable where the environmental conditions of operation vary widely and especially when the connector must be operable continuously at relatively high temperatures. If the requirements are not so severe, other materials may be used.. For example, a semi-hard rubber material having a modulus of elasticity on the order of 300,000 pounds per square inch may be used when operation at high temperatures is 49 and 50 include planar portions 51 and 52 of substantial area which surround the ends of the contact passages, the planar portions 51 and 52 being brought into firm pressure engagement when the connector is assembled and being operable to provide a sealing action and also to preven the formation of fluid-entrapping pockets. 11th the use of a semi-hard material as above described, the surfaces ca readily conform to each other to obtain such results with only a moderate amount of force exerted* while slight inaccuracies in the surface portions can be accommodated.

The surface 50 includes an integral riser 53 which may be also called an "integral neck" about the end of the passage 16, adapted to enter an end portion 54 of the passage 15, with the oute surface of the riser 53 and the inner surface of the end portion 54 being in pressur sealing engagement.

Preferably, one of such surfaces is frusto-conlcal In shape while the other is cylindrical with the diameter of the cylindrical surface being intermediate the diameters of the frusto-conical surface at the opposite ends thereof, This facilitates alignment during assembly while insurin a pressure seal. Most preferably, it is the outer surface of the rise 53 which Is frusto-conical in shape and with the base or largest diameter portion of the riser 53 being surrounded by the planar surface 52, the maximum pressure point is at the junction between the planar surface 52 and the surface of the rise 53 so tha the ormation of luid pockets is obviated.

T e manner of interengagement of the surfaces is illustrated in FIGURES 3, 4 and 5. FIGHJRB 3 shows the relation of the surfaces 49 and 50 before they are brought into engagemen , FIGURE 4 shows the relation of the surfaces when initial contact is made and F10UBE 5 shows the surfaces fufl Interengaged. It will be noted that before the surfaces are brought into engagement, surface of the riser 53* while being greater than the smaller diameter terminal end of the frusto-conical surface of the riser 53 . Thus with the parts prefectly aligned, the initial contact is at an intermediate point of the frusto-conical surface of the riser 53 , as shown in FIGURE 4. Due to the fact that the diameter of the frusto-conical surface of the riser 53 at the terminal end thereof is less than the diameter of the inner cylindrical surface of the portion 54 , slight inaccuracies in alignment can be accommodated and the surfaces are moved into proper engagement when moved together. As shown in FIGURE 5» when. the surfaces 9 and 50 are fully interengaged, the riser 53 is deformed at the base portion of the frusto-conical surface thereof and there is also a deformation at the end of the inner surface of the portion 54 , resulting in increased pressure and a tight fluid seal. It should be noted, also, that the planar surface portions 51 and 2 are brought into pressure engagement so that there can be no fluid-entrapping pockets in which corona discharges might occur.

The overall result is a highly effective and reliable fluid seal about each of the pairs of mating contacts, it being noted that the telescoping riser arrangement is provided about each of the pairs of mating contacts of the connector. spring arrangement for obtaining optimum pressure engagement between the surfaces 49 and 50 of the dielectric members 17 and 18.· In accordance with this feature, an annular wave spring 56 is disposed between an outwardly extending integral annular flange 57 of the plug shell 19 and. an inwardly extending integral annular flange 58 of a member 59 which, for convenience in assembly, is threaded into the coupling ring 21 , the member 59 and the flange 58 thereof being rigidly secured in the ring 21 after assembly. The wave spring 6 is of a type known in the art and is like number of equi-angularly spaced points.

Before assembly of the connector, movement of the flange 57 away from the flange 58 is limited by an inwardly extending integral annular flange 60 of the coupling ring 21 . In assembly, the keys and keyways are aligned and the mating contacts are brought into initial engagement after which the coupling ring 21 is rotated to be screwed onto the receptacle shell 20 , bringing the contacts 11 and 12 and also the sealing surfaces 49 and 50 into full engagement. Movement of the coupling ring 21 is limited by engagement of the flange 60 with the end of the receptacle shell 20 and metal bottoming action results, the torque required to turn the coupling ring 21 quickly escalates and can be readily felt by the operator so as to Indicate by feel that the connector is fully mated.

When so mated, the wave spring 56 exerts the required forces to obtain optimum pressure sealing engagement between the surfaces 49 and 50. It should be noted that due to differences in temperature coefficients of expansion and contraction, the force exerted may vary to a small degree but the relative dimensions are such as to maintain the forces within an optimum range of values.

With regard to dimensioning, it is noted that the configuration of the end surfaces 49 and 50 of the dielectric members 17 and 18 is important, particularly with respect to the telescoping risers and with a semi-hard material having characteristics as above set forth, the outside diameter of the dielectric members 17 and 18 may be on the ' order of one inch and other dimensions are in the same proportion as illustrated in the drawings.

As shown in FIGURE 5 , the contact 11 is in the form of a male contact having a reduced diameter portion 62 extending with-in an opening 63 in a main conductive body part 64 of the female contact 12 . The body part 64 is formed with a pair of diametri- 65, call o osed slots /to rovide a air of tines en a in th or disposed around the tines so formed and a shroud 67 is preferably disposed around the portion of the body 64 having the opening 63 and slots 65 therein. Preferably, the terminal end of the portion 62 of contact 11 is beveled or pointed, the terminal end of the shroud 67 is turned inwardly and a frusto-conical surface 68 is formed in the passage 15, extending inwardly from the portion 54, with the relative size and dimensioning being such that the contacts 11 and 12 will engage and mate even though bent out of position when the connector is assembled.

It may be noted that a dual spring action results from the combination of the tined construction and the pressure band 66, the tined construction providing a soft spring action which encompasses the complete maximum deflection range while the band 66 provides a hard spring action to produce adequate force for minimum deflection range. The shroud 67, which may be of stainless steel, limits the deflection of the tines and provides a closed entry restriction for oversized probes.. in the passages of the dielectric members in a manner such as to permit removel and replacement of contacts without destruction of parts and without requiring the scrapping of an entire connector, plug or receptacle.. The illustrated contact 11 is held in place by means of a retention member 70 surrounding a portion of the contact 11 and having an annular 71 groove/in its outer surface which receives an inwardly extending ,72 annular projection/ formed in the contact passage 15. Movement of the contact 11 to the right as illustrated in FIGURE 5 Is limited by engagement of an annular flange 73 of the contact 11 with one end of the retention member 70. To limit movement in the oppo-site direction, to the left as viewed in FIGURE 5, the retention member 70 has a pair of diametrically opposed slots to define a a o s o 4 ach o wh ch for d w th a on the contact 11 .

In assembly, the retention member 70 is first installed after which the contact 11 is inserted from the left, as viewed in FIGURE 5 , the spring tines or fingers 74 of the retention member 70 being engaged initially by a frusto.-conical surface 77 of the contact 11 . When the contact 11 reaches a position as illustrated in FIGURE 5, the fingers 74 spring inwardly to engage the shoulder 75 thereof with the shoulder 76 of the contact 11 .

T ¾^a&»egga¾ee-w 4^^-opo' It will be appreciated that the sharp blow required for such removal is much greater than would be encountered in operation of the connector, but can be applied when removal and replacement of the contact is required,. It is important to note that the retention member is not damaged, nor is the dielectric member 17 damaged, by contact removal and it is not necessary to scrap the entire connector plug.

The construction is such that the contacts can be removed using hand tools which slide in. and engage the fingers 74 to move them outwardly in which case the contacts are not damaged. The however, such hand tools are not conveniently available. The contact 12 may be held in place by means of a retention member 81 identical to the retention member 70 and operable in a manner operable and identical thereto. It is noted that the male and female or pin and socket connectors 11 and 12 along with their respective dielectric bodies may be reversed relative to the plug and receptacle shells 19 and 20. Thus the male or pin contacts 11 may be disposed within the receptacle shell 20 and the female or socket contacts 12 may be disposed within the plug shell 19. In this connection, it is noted that the positions of the enlarged diameter portions 37 and 38 of the dielectric member 17 and 18 and the positions of the shoulders 39 and 40 and retainer rings 41 and 42 are the same relative to the ends of the shells.

It is additionally noted that although not forming part of the present invention, special seal members 83 and 84 are provided around the wires 13 and 14 in the passages 15 and 16 and similar members are provided about the other wires.

It will be understood that modifications and variations may be effected without departing from the spirit and scope of the novel concepts of this invention. 33707/2

Claims (8)

1. An electric connector comprising a pair of dielectric members, a pair of hollow shells supporting the pair of dielectric members therewithin and arranged to be secured together to hold end surfaces of the dielectric members together in pressure engagement, the pair of dielectric members each having at least one passage therethrough, the passages being aligned in use, and contacts supported In the passages and adapted to be brought into mating electrica contact when the end surfaces are brought together in pressure engagement, the con iguration of the end surfaces and the characteristics of the material of the dielectric members being such as to provide a fluid tight seal between the end surfaces whilst providing firm support for the contact, the end surfaces including an integral neck about one end of a passage of each pair of aligned passages adapted to enter and be p, compressively deformed by an end portion of the other passage, the end surfaces of the pair of dielectric members including planar portions of substantial areas in surroundin relation to the passages, the planar portions being firmly engaged when the shells are secured together to prevent the formation of fluid-entrappin pockets.

2. An electrical connector as claimed in Claim 1, in which an outer surface portion of the neck and an inne surface portion of the end portion of the other passage are in pressure sealin engagement when the shells are secured together.

3. An electrical connector ae claimed in Claim 2, in which one of the inner and outer surface portions is of generally fusto-conical shape and the other is generally cylindrical, the diameter o the cylindrical surface portion having a value between the values of the minimum and maximum diameters of the frusto-conical surface portion,

4. An electrical connector as claimed in Claim 3# in which the oute surfce portio of the neck is frusto-conical in shape and the inner surface portion of the end portion of the other passage is generally cylindrical.

5. An electrical connector as claimed in Claim 1, in which coupling ring is provided, spring means acting between the coupling ring and one of the pair of shells, the coupling ring and the othe of the pair of shells being adapted for threaded inter-engagement to cause; the spring means to exer a force urgin the end surfaces of the dielectric members into pressure engagement.

6. An electrical connecto as claimed in Claim 5» in which the coupling rin and the other of the pair of shells have stop surfaces adapted to interengage to limit their relative movement and to cause a predetermined engagement force to be exerted between the end surfaces o the dielectric members.

7. An electrical connector as claimed in Claim 1* in which each of the dielectric members is of a substantially homogeneous semi-hard material as herein defined,. 55707/2 - 1 - 8. A electrical connector as claimed in Claim 1, in which the contacts in the passages have annular recesses therei between the opposite ends thereoff the connector further, including a retention member around each of the contacts withi the passages and interengagin means between each of the retention members and its respective passage for locking the retention member against movement along the passage, the retention member being of a hard spring metal and having spring inge means loekingly engaging the respective contact to retain it, which contact is of a relatively soft conductive metal to permit the contact to be forcibl driven out from the retention member without damage to the retention member Or the dielectric members, 9» An electrical, connector as claimed in Claim 8, in which each of the contacts has an annula shoulder and the sprin means has a shoulder means adapted to normally engage the annular shoulder of the contact, the shoulder means of the spring finger means being adaptsd to cut throug the shoulder of the contact when the contact is forcibl driven out from the retention member, 10. An electrical connector as claimed i Claim 7» in which each of the dielectric members has a modulus of elasticit of the order of 500,000 poundB per square inch. 11· An electrical connector as claimed in Claim » i which each of said dielectric members is of a polymer material having a basic polymer structure consisting of phenyl and biphenyl units linked by oxygen and sulfone groups. 1 33707/2 - 18 - 12. An electrical connector constructed and arranged to operate substantially as herein described with reference to and as illustrated in the accompanying drawings. For the Applicants ARTNER

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