US 3792418 A
Description (OCR text may contain errors)
United States Patent Kailus [451 Feb. 12, 1974 211 App]. No.: 177,730
US. Cl. 339/177 R, 339/278 D Int. Cl. H01! 17/06 Field of Search. 339/60, 61, 89 C, 90 C, 91 P, 339/94 R, 94 C, 94 M, 126 1,136 C, 177 R, 177 E, 278 D; 174/75 C, 88 C, 89
1,929,846 12/1970 Germany 339/177 R OTHER PUBLlCATlONS The Condensed Chemical Dictionary, 8th Ed., July 6, 1971, pages 712 & 713.
Primary Examiner-Marvin A. Champion Assistant Examiner-Lawrence J. Staab Attorney, Agent, or Firm-F. M. Arbuckle; W. Lohff [5 7] ABSTRACT A high-temperature electrical connector including interengageable mating sections each having a central and an outer-tubular metallic contact and an insulating sleeve disposed therebetvveen with the insulating sleeve of the one section having self-lubricating surfaces of a fluorocarbon engaging the sleeve or its associated outer-tubular metallic contact of the other section, the fluorocarbon having a relatively low heat deflection temperature so as to deform at high temperatures. The other insulating sleeve is composed of a material such as an aromatic polysulfone with a relatively high heat deflection temperature to provide a relatively rigid support for the fluorocarbon sleeve.
6 Claims, 6 Drawing Figures /9, \Y I /52 x my PATENTED FEB 1 2 I974 sum 1 0F 2 INVENTORJ V a 4? i,
ATTORNEYS ELECTRICAL CONNECTOR BACKGROUND OF THE INVENTION In connectors of the plug-and-receptacle type, interengageable connector sections are mated to provide electrical connection between centrally-mounted mating contacts and to interconnect protective housings surrounding these contacts. In one type of connector, the housings are composed of insulating materials with at least one housing being shaped as a sleeve to receive the other in engaging relationship.
In another type, the housings are metallic to provide electrical shielding of the central contacts and insulating members are provided to isolate the central and outer contacts. In one example of the second type of connector used at elevated temperatures (e.g. 250300 F.), one of the insulating members longitudinally extends as a sleeve between the central and outer contacts and abuts against the other insulating member rearwardly located in the connector section.
As the temperature requirements of these connectors have increased, it has been necessary to provide dielectric materials for the sleeves which are insulatively stable at the higher temperatures in addition to having other properties required for connector housings.
Some materials, while insulatively stable at temperatures of 400-5 F.,are so rigid that they do not easily mate; and in those instances where a seal is to be established, these materials .are not sufficiently yieldable to provide sealing effect.
Another problem associated with some materials insulatively stable at temperatures of 400500 F. is that they tend to distort at the higher temperatures and this distortion interferes with the desired mating of the connector sections. In some instances, it is possible for the mating surfaces of the same material to lock and resist separation of the sleeves during attempts to release the connector sections. Among the materials having heat distortion properties which can result in this problem are the self-lubricating fluorocarbons and particularly polytetrafluoroethylene.
SUM MARY This invention relates to electrical connectors with interengageable mating sections in which an insulating sleeve on one of the sections is mated within a complimentary protective housing on the other section. The sleeve is composed of a self-lubricating fluorocarbon with a relatively low heat deflection temperature and thereby heat distortable in a mating relationship with the complimentary protective housing. More particularly, the invention is directed to an electrical connector with interengageable mating sections in which the complimentary protective housing engageable with the fluorocarbon sleeve is composed of a material having a relatively high heat deflection temperature-to maintain the mating relationship while permitting the sections to be released at high temperatures. Exemplary of a material with such high heat deflection temperatures is an aromatic polysulfonc which is insulatively stable at temperatures of 400-500 F. and also has a heat deflection temperature of over 500 F. at 264 psi as measured .in ASTM D 648-56.
Several advantages result from the electrical connector of the invention. One is the utilization of a high temperature, self-lubricating fluorocarbon as an elongated insulating sleeve in the connector construction. In addition to its useful high-temperature properties, the fluorocarbon provides self-lubricating properties and thereby can be easily inserted within or over a complimentary protective housing without requiring the second housing to be similarly self-lubricating. It is also sufficiently yieldable .to form an interference fit with the complimentary housing.
Another advantage is provided by the combination of the fluorocarbon sleeve with a complimentary protective housing composed of a material comparatively rigid at the higher temperatures. The rigid housing provides a mating surface which resists distortion and permits release of the connector sections.
Another advantage is provided by the use of a complimentary protective housing mateable in an engaging relationship with the fluorocarbon sleeve and composed of a material having a high heat deflection temperature to maintain the engaging relationship without preventing the connector sections from being released.
In those instances where a seal is desired, a further advantage is provided at the high temperatures when the fluorocarbon sleeve includes a raised collar which tightly bears against the mating surface of the rigid complimentary housing. Although the raised collar is under stress and distorted by the heat, it tends. to conform to the mating surface of the rigid material and maintains some sealing effect.
DESCRIPTION OF THE DRAWING In the drawings FIG. 1 is a side view in cross section of the electrical connector of the invention.
FIG. 2 is a side view in cross section of a second embodiment of the connector of the invention.
FIG. 3 is a side view of a third embodiment of the connector of the invention.
FIG. 4 is a side view partially in cross section of one of the mating sections of the connector of FIG. 1.
FIG. 5 is a side view partially in cross section of the second mating section of the connector of FIG. 1.
FIG. 6 is a side view in cross section of a socket contact of FIG. 2.
GENERAL DESCRIPTION The electrical connector of the invention is designed for high temperature use and comprises first and second interengageable mating sections, each with a protective body containing one or a plurality of contactreceiving bores and contacts mounted therein. In one mating section, the body includes one or a plurality of yieldable sleeves extending around the contacts in the bores with self-lubricating surfaces adapted to easily slide against surfaces in the other mating section while being insulatively stable at temperatures in the order of 400-500 F. The protective body of the second mating section includes a similar number of bores and complimentary contacts mounted therein to mate with those contacts in the first section. Advantageously, the second protective body provides one or a plurality of insulating surfaces insulatively stable at the higher temperatures and relatively rigid to accept the self-lubricating surfaces of the sleeves and form insulated enclosures around the mated contacts.
Preferably, the self-lubricating surfaces are composed of a fluorocarbon such as polytetrafluoroethylene and provide self-lubrication at temperatures of 400500 F. Since the fluorocarbons with these characteristics tend to be heat distortable as illustrated by low heat deflection temperatures (e.g. below about 300 F. at 66 psi as measured in ASTM D 648-56), the adverse effects of heat distortion on the mating surfaces of the connector are reduced by including as the complimentary mating surface, a material which is relatively rigid at the higher temperatures. Advantageously, when the mating is accompanied by bearing stress on the adjacent surfaces, the fluorocarbon surface includes a raised portion as a bearing surface which can be heat distorted while maintaining engagement with the adjacent surface which can be formed to permit easy release of the mating sections.
Connectors according to the present invention are applicable to a wide variety of constructions but in a typical installation will comprise one or a plurality of pairs of interengageable mating sections and 12 with mating contacts 14 and 16 made of leaded copper and centrally mounted in their respective sections.
As illustrated in FIG. 1, first section 10 includes central contact 14 with forward pin 18, rear socket 20, and intermediate cylindrical portion 21 for mounting the contact in section 10. Second section 12 includes central contact 16 with forward socket 22, rear pin 23 swagged in a bussing ring 24, and intermediate irregular surfaces 25 for mounting in section 12. Bussing ring 24 is part of a bussing assembly described in my copending application entitled CONNECTOR MOD- ULE" and filed Sept. 7, l971 as Ser. No. l78,097.
Disposed around and laterally spaced apart from contact 14 are protective sleeve 26 of plastic such as the described fluorocarbon and sleeve 27 of berryllium copper which serve respectively for insulating and electrical shielding purposes. Sleeve 26 is disposed between contact 14 and outer-tubular contact of sleeve 27 and includes mating end 28 which engages section 12 when sections 10 and 12 are mated. As illustrated, sleeve 26 includes an outer peripheral surface 29 with laterally projecting riser 30 which extends around surface 29 in a direction normal to the longitudinal axis 31 of sleeve 26 and is designed to telescopingly engage with surface 34 of section 12. Mating end 28 except for riser 30 is sized so as to be spaced apart from sleeve 27 to permit release of the sleeves. As illustrated, sleeve 26 extends longitudinally beyond contact 14 and is laterally spaced apart from the contact.
Section 12 also includes protective sleeves 32 and 33 which provide insulative and electrical protection for central contact 16 in a similar manner to sleeves 26 and 27 in respect to contact 14. The combination of sleeves 32 and 33 provides at least one surface illustrated in FIG. 1 as surface 34 on sleeve 33 for snug engatement and more advantageously an interference fit with riser 30 of sleeve 26. Sleeve 33 includes mating end 35 from which surface 34 extends rearwardly as a smooth annular shape with a minimum cross section at mating end 35 in order that the heat deflection and distortion in sleeve 26 will not result in the interlocking of sleeves 26 and 33 together. Since riser 30 also serves for sealing purposes, it is preferred that surface 34 be circular with its diameter remaining essentially constant for length 36 over which riser 30 passes.
In some instances, as illustrated in FIG. 2, connector sections 13 and are provided in which section 15 includes metallic, sleeve 37 with surface 38 for mating with riser 39 of sleeve 40 and no separate insulating sleeve is provided. Metallic sleeve 37 also includes outer surface 41 for mating with metallic sleeve 42 to provide electrical connection between the two outer contacts. Sleeve 42 includes mating end 43 shaped as a spring 44 which resiliently bears against metallic sleeve 41. As illustrated, section 15 is formed with glass insulator 85 as part of a hermetic seal (not shown).
As illustrated in FIG. 3, insulating sleeve 45 can provide surface 46 upon which riser 47 engages during the mating. In this embodiment, central contacts 48 and 49, insulating sleeves 45 and 50, and outer tubular contacts 51 and 52 respectively become mated. As illustrated, sleeve 50 is sized so as to telescope over surface 46 of sleeve 45 with riser 47 engaging surface 46.
Mating sections 10 and 12 of FIG. 1 are releasable and separately illustrated in FIGS. 4 and 5 respectively. Contact 14 is centrally mounted on internal collar 53 of sleeve 26 and locked into its position along longitudinal axis 31 by retainer clip 54 of beryllium copper which includes a forwardly extending inwardly tapered end 55 which engages shoulder 56 of cylinder 21 on contact 14 and resists movement in a rearward direc tion. Rear sleeve 57 of clip 54 serves to prevent contact 14 from moving in a forward direction by engaging outer flange 58. Clip 54 includes outer collar 59 snugly positioned between shoulder 60 of sleeve 26 and surface 61 of rear insulator 62 of a high-temperature plastic to retain clip 54 in section 10.
After an external contact (not shown) is connected to socket 20 and its shielding cable is connected to rear ferrule 63, connector section 10 is potted by pouring a potting compound into aligned apertures 64 and 65 in sleeves 26 and 27 respectively. In this operation, the rear internal end 66 becomes potted and retains rear insulator 62, sleeve 26, and contact 14 in position. The potting compound is prevented from entering socket end 20 by the presence of the external contact. Outer metallic sleeve 27 is formed as spring 67 on mating end 68 and when mated with sleeve 33 (FIG. 5), bears against its surface 69 with sufficient force to prevent accidental removal of the sections 10 and 12. Spring 67 is conveniently formed with an inwardly depressed bow 71 which extends to a forwardly positioned, inwardly bent hook 72.
FIG. 5 is illustrateive of mating section 12 without central contact 16 and includes internal collar 73, retainer-clip 74, and rear insulator 75 similar to those members described for section 10. Sleeve 32 is cylindrical shaped and extends forwardly with smooth inner and outer surfaces 76 and 77 to mating end 78.
Central socket 79 for the mating section 13 of FIG. 2 is illustrated in FIG. 6 and includes forward and rear sockets 80 and 81 separated by cylindrical mounting portion 82. Forward socket 80 includes pressure spring 83 to bias socket 80 inwardly. A forwardly hooked hood 84 is fastened over socket 80 and limits the outward deflection of socket 80.
The foregoing description of the present invention is only illustrative of an exemplary form which the invention may take. Still other modifications and variations will suggest themselves to persons skilled in the art. It is intended, therefore, that the foregoing detailed description be considered as exemplary only and that the scope of the invention be ascertained from the following claims.
1. An electrical connector comprising first and second interengageable mating sections, each including at least one central metallic contact and outer protective longitudinally elongated sleeve therefor, the sleeve of the first section being composed of a self-lubricating fluorocarbon having a heat deflection temperature below about 300 F. at 66 psi and having a mating end with an inwardly projecting lateral riser sized to telescope over and engage the sleeve of the second section with said mating end except for said riser being sized so as to be spaced apart from the second sleeve to permit release of the sleeves, the second sleeve'having a mating end with a periphery of an essentially constant cross-sectional dimension along the longitudinal axis for engagement with said riser and being composed of a material having a heat deflection temperature above about 400 F. at 264 psi, the riser bearing against said periphery with a laterally directed force when said sections and sleeves are mated.
2. The electrical connector of claim 1 wherein each of said sections includes a second metallic contact outwardly disposed about said sleeve as a shield for the central contact with the shield for one of the central contacts including an inward curve to form a spring means for engagement with the shield for the other of said central contacts, and thesleeve of said second section is a thermoplastic polysulfone.
3. The connector of claim 1 wherein said sleeve with said riser extends longitudinally beyond said central contact and is laterally spaced apart therefrom.
4. The electrical connector of claim 3 wherein said second sleeve is a plastic sleeve disposed around and spaced apart from said central contact and said plastic is a polysulfone.
5. The electrical connector of claim 4 wherein said riser extends radially around said mating end for sealing engagement with the mating end of the sleeve of the second section.
6. The electrical connector of claim 5 wherein said fluorocarbon is polytetrafluoroethylene.