Патент USA US2405881код для вставки
Aung. 13, 1946. J. R. FREI ' 2,405,881 ELECTRICAL CONNECTING MEANS AND RADIO SHIELDI'NG MEANS THEREFÓR Filed.> May 6, 1941 l n I l M È 0d .' INVENTOR ATTORNEY Patented Aug. 13, 1946 2,405,881 UNITED STATES PATENT OFFICE 2,405,881 ELECTRICAL CÜNNECTING MEANS AND RADIO SHIELDING MEANS THERE FOR i Jakob R. Frei, Sidney, N. Y., assignor to Bendix Aviation Corporation, South Bend, Ind., a cor poration of Delaware Application May 6, 1941, Serial No. 392,032 14 Claims. l (Cl. 174-35) 2 This invention relates to electrical apparatus, and more particularly to electrical connector ters refer to like parts throughout the several means adapted for use in a radio shielded ignition system of an internal combustion engine. Fig. l is a full size side elevation, partly in sec tion and with parts broken away, of apparatus embodying one form of the present invention; Fig. 2 is an enlarged detail view, partly in sec tion and with parts broken away, showing the plug portion of the connector of the apparatus of In been tems spite spite of the fact that radio-shielding has considered an essential part of ignition sys on aircraft engines for many years, and in of the fact that the connection between the views, shielded high tension supply cable and the shield Fig. 1; ed spark plug has long been recognized as the l0 Figs. 3 and 4 are enlarged detail views, partly weakest link in such systems, no truly satisfactory in section and with parts broken away, illustrat connector for this purpose has been heretofore ing other embodiments of the insulated connector devised, although innumerable attempts have constituting a part of the present invention and been made to solve this diñicult problem in a adapted for use in the apparatus of Fig. 1; and, practical manner. 15 Fig. 5 is a View similar to Fig. 2 of another em It is accordingly an object of this invention to bodiment of the plug portion of a connector. provide a novel and practical connector of the The embodiment of the invention shown, by above character. way of example, in Fig. 1 of the drawing is illus Another object of the invention is to provide a trated in conjunction with a shielded spark plug novel insulating member which is associated in a 5 of the type now in almost universal use on air novel manner with an electrical conductor and craft engines. Said spark plug may be of any radio-shielding means therefor. suitable internal construction and comprises a Still another object is to provide insulating center electrode 6 which is insulated from the means for an electrical conductor which is so con outer shell or casing ‘I’ 8 which includes a shield stl‘ucted as to _cooperate in a novel manner with a ing barrel or socket 9 that surrounds and extends radio-shielding conduit for said conductor and beyond the upper end of said electrode and is the radio-shield of a spark plug. lined with a tube of electrical insulating material A further object is to provide novel insulated I0, such as sheet mica. The upper portion of conductor means for electrically connecting a barrel 9 is externally threaded at I I for a purpose pair of conductors of high tension electrical n to appear hereafter. current. For the purpose of- conducting high tension A still further object is to provide novel means electrical current to electrode 6 of the spark plug for electrically connecting a high tension insu there is provided an insulated cable I2, the con lated cable to the center electrode of a radio ducting portion I3 of which is preferably consti shielded spark plug whereby the cable insulation tuted by several strands of stainless steel or other is protected from the deleterious effects of high suitable conducting material. 'Ille insulation I4 temperatures, hot gases and moisture, on said cable is preferably constituted by a mate Another object is to provide novel plug and rial which will resist the deleterious effects of socket connecting means for electrically connect high temperatures, such as an insulation having ing high tension electrical conductors whereby 40 a base of polymerized cashew nut shell oil. Cable good electrical contact between the conducting I2 is encased in a metallic conduit I5 to obviate parts is obtained and the possibility of arcing be the radiation of electrical disturbances which in tween the high tension conductors and the con terfere with radio reception. Said conduit may necting means is reduced to a minimum. comprise a flexible portion I6, a rigid elbow I1 The above and further objects and novel fea and a ferrule I8, said parts being secured to tures of the invention will more fully appear from gether by any suitable means, such as soldering the following detailed description when the same or brazing. In order to removably secure the is read in connection with the accompanying shielded conduit to spark plug barrel 9, ferrule drawing. It is to be expressly understood, how I8 is preferably provided with an external liange ever, that the drawing is for the _purpose of illus 50 I9 for cooperation with an internally threaded tration only and is not intended as a definition of coupling nut 20 which also cooperates with the limits of the invention, reference for this lat threaded portion II of said barrel. The space ter purpose being had primarily to the appended within conduit portions I6 and I‘I, around cable claims. I2, is preferably filled with a suitable solid in In the drawing, wherein like reference charac 55 sulating material 2| which serves to prevent vi 2,405,881 3 to obviate arcing therebetween must be assured. bration of the cable relative to the conduit and to To this end, therefore, insulating tube 22 and prevent any accumulation of moisture in the con ferrule I8 of conduit I5 are operatively connected duit by condensation or otherwise. The filling in a novel manner. Said ferrule is provided with material also prevents any substantial axial a small number of internal threads 30 which are movement of cable I2 relative to the shielding adapted tc cooperate with external threads 3I conduit and may consist of polymerized cashew on the upper end of molded tube 22. The inner nut shell oil. This material may be inserted in diameter of ferrule I8 interiorly of threads 30 is the conduit in liquid form and permitted to set sufñciently large to accommodate the threaded through chemical reaction without appreciable portion of tube 22 so that the latter may be freely 10 shrinkage. rotated relative to the shielding conduit when the Novel means adapted to slidably extend into cooperable threads are disengaged and may be socket 9 are provided for electrically connecting conductor l2 to center electrode or conductor E of the spark plug, for spacing exposed portions of moved axially relative to said conduit to insure good electrical contact between cable I2 and 23 when the parts of the apparatus are the high tension conductors from the grounded 15 member assembled and to obviate placing said tube under portions of the radio shielding parts a suñicient a stress which might cause the same to crack. distance to prevent flash-overs under normal opn rThis relative axial movement may be limited to erating conditions and for protecting that portion the diiierence between the axial extent of threads of cable I2 which projects from elbow I'I from 3| and the distance between threads 3d and a the deleterious efîects of high temperatures, hot shoulder 32 within ferrule I8. Preferably, how gases which may leak through the spark plug in ever, said axial movement is limited to the dii~ sulation, electrical arcing from the high tension ference between the axial extent of threads 30 conductors to grounded portions of the shielded and the distance between threads 3i and an anN parts, and moisture. Said novel means in the form shown in Figs. l and 2 comprise a cylindri 25 nular shoulder 33 which is formed integrally with tube 22. cal sleeve or tube 22 of insulating material, such Although annular shoulder 33 is not absolutely as molded ceramic, “Melmac” (a synthetic resin) necessary, the same is preferably provided for or the like, which is capable of withstanding high temperatures and rough usage and has a high re `the purpose of ñxing tube 22 against move sistance to carbonization under arcing conditions. 30 ment relative to barrel S and conduit I5 when the parts are in assembled relation. Said shoul der may be covered with a gasket 34 of copper or other suitable material and is adapted to ex end of insulated cable I2 which projects from tend between the adjacent ends of said conduit conduit I5 and the lower portion thereof may be slightly enlarged for receiving a hollow metallic 35 and barrel. Cable I2 .preferably projects from the shielding conduit a sufficient distance so that it member 23, the latter being closed at its upper engages member 23, 24 just prior t0 the engage end and having a pointed projection or spike 24 , ment of ferrule I3 and shoulder 33, 34 (Fig. 2) adapted for abutting engagement with stranded so that when coupling nut 25 is screwed home conductor I3 at the end of cable I2. Cup-shaped (Fig. l) to ñrmly clamp said shoulder between 40 member 23 is iitted into the bore of tube 22 and~ the ends of barrel il and ferrule i8 the cable will held therein in substantially gas-tight relation be placed under some compression and may with the walls of said tube by cement or other buckle slightly, thereby insuring good electrical suitable means. If cement is used for this pur contact even though the cable may shrink soma pose, the outer surface of member 23 may be pro what under the action of the hea-t during use. vided with shallow annular or helical grooves or 45 Securing the parts together in the above man the like to enhance the effectiveness of the ce ner also results in the provision of a seal at ment as a retaining and sealing medium. shoulder 33, 34 against the entrance of moisture A contact pin 25, having a ball-like portion 2G from outside the shielding means and against at its lower end and a piston-like portion 2l at its any leakage of hot gases from the spark plug well 50 upper end, is slidably mounted in ‘the hollow or into the space within ferrule I8 around cable l2 recessed part of member 23 and projects from and insulating tube 22. The seal thus provided tube 22 for yieldable electrical contact with cen is effected without subjecting the insulating ma ter electrode 6. Suitable means are provided for terial of tube 22 to any twisting moments or limiting the outward movement of contact mem strains which might cause breakage thereof. Vi~ ber 25 and, in the form shown, such means is bration of the insulating tube relative to the spark constituted by a washer 28 held in member 23 by .plug is also avoided by clamping the tube in po spinning the edge of the latter inwardly. In sition. terposed between the closed end of member 23 In order to further insure against arcing or and contact pin 25 is a compression spring 2S between terminal 26 and the inter which normally holds said pin in extended posi 60 flash-overs nally exposed metal at the upper end of barrel 9 tion (Fig. 2) and is adapted to insure goed elec and between the end of cable l2 and metallic trical contact between ball 25 and electrode 5 conduit I5, the annular spaces 35 and 36 between when the plug and socket portions of the inven tube 22 and barrel 9 and between cable I2 and tion are assembled (Fig. l). The parts 23, 25 and said tube, respectively, may be sub-stantially iîlled 29 thus constitute axially yieldable means for 65 with a viscous insulating material, such as “Tite electrically connecting conductors 6 and I3, said Seal,” which is a mixture comprising castor oil means having abutting engagement with said and mica powder and having the consistency of conductors to facilitate disassembly of the parts. grease. This material also avoids the formation It is highly desirable that the insulating sleeve of moisture paths along the insulating materials 70 22 be operatively secured to conduit I5 for re which might promote flash-overs between the moval therewith from spark plug 5 and yet be high tension conducto-rs and the grounded metal readily removable from said conduit for purposes lic parts. of inspection and replacement. At the same time rI’he embodiment illustrated in Fig, 3 differs a sufficiently good contact between the conduce from that above described in that spike 24 is re tors 6 and I3 and the connecting means therefor The upper portion of the bore in sleeve 22 is pref erably just large enough to slidably receive the 5 2,405,881 6 \ placed by a spirally coiled spring 31. The latter has the largest turn thereof interposed and clamped between member 23 and an internal shoulder 38 in the bore of insulating tube 22. When this embodiment is used, good electrical contact with conductor i3 is doubly insured. In order to prevent any possible catching between conductor I3 and spring 3l, a tack 39 with a smooth, enlarged head may be stuck into the end of cable l2. In the modiiication illustrated in Fig. 4, an open-ended cylinder 4D is provided in lieu of member 23 of Fig. 1. lI‘he upper end of said cyl inder is closed by a cup-like member 4| having an external ñange or bead 42 at the open end thereof which is slidable in the cylinder and re tained therein by an internal iiange 43. A co-m .pression spring 44 is interposed between mem ber 4l and contact plunger 25, thereby providing out departing from the spirit and scope of the invention as the same will now be understood by those skilled in the art. For a deñnition of the limits of the invention, reference is had primarily to the appended claims. What is claimed is: l. In apparatus of the class described a me tallic socket lined with electrical insulating ma terial and having an electrical conductor therein, a radio shielding conduit, means for securing said socket and conduit together in axial align ment with each other, a tube of electrical insu lating material removably mounted in said con duit and slidably extending into said socket, said 15 tube having an enlarged annular portion inter posed between and in sealing relation with the adjacent ends of said conduit and socket, an in sulated electricalr conductor extending through said conduit into said tube, means in said conduit yielding contact means for both conductors 6 and 20 for holding said insulated conductor against sub i3, Member 4| may, of course, be replaced by a stantial axial movement relative thereto, a hol plunger similar to plunger 25 or by any other low metallic member filling a portion of the bore suitable equivalent structure. in said tube at the end of the latter within said In Fig. 5 there is illustrated still another em socket, the closed end of said member being ad bodiment of the plug portion of the connector- in 25 jacent said insulated conductor and having abut which an insulating spacer sleeve 22a is remov ting electrical contact therewith, resilient means ably mounted by means of cooperating screw in said member, a contact plunger slidably mount threads in a metallic ferrule [8a that is secured ed in said member and interposed between said to metallic shielding elbow Il to form a shield resilient means and the conductor in said socket, ing conduit. The cooperating screw threads on and cooperable screw threads on said tube and parts |8a and 22a are coextensive and the latter in said conduit, said threads being disengaged is screwed home, so to speak, in the ferrule so when the conduit and tube are assembled to that the upper end of the insulating tube or sleeve thereby permit limited axial movement of the engages an internal shoulder 32a of the shielding tube relative to the conduit. conduit to thereby form a gas-tight seal and 35 2. In connector means for radio-shielded con prevent the leakage of gases and moisture from ductors of high tension electrical current, a metal the spark plug well into the space around cable lic conduit, an electrical insulating tube project l‘2. When this embodiment is assembled with a ing from one end of said conduit and removable spark plug 5 (Fig. l), the lower face of flange Illa is pressed into sea-ling engagement with the 40 therefrom through said end, and cooperable means integral with said conduit and tube for upper end of shielding barrel 8 by nut 23, thus normally retaining the end of said tube in said obviating any strains or stresses on insulating conduit while permitting rotational and limited tube 22a. Any suitable electrical conducting axial movements of said tube relative to the con duit, said rotational and axial movements being 22a, the means shown being identical with that 4.5 adapted to take place independently of each other. illustrated in Fig. 3. means may be provided in the lower end of tube There is thus provided novel means for elec 3. In connector means for radio-shielded con ductors of high tension electrical current, a radio shielding conduit, an insulated electrical con ductor in said conduit, means in said conduit for nection and the connection of the shielding means GO ñxing said conductor against substantial move therefor may be readily and quickly effected and ment relative thereto, a tube of insulating mate~ whereby good electrical connections are assured. rial extending into the end of said conduit and Novel means of the above character are also pro surrounding a projecting portion of said conduc vided whereby the effects of high temperatures, tor, and means including cooperable screw threads moisture, arcing and rough handling are eilec 65 on said tube and in said conduit for removably tively minimized. A novelly constructed insulat retaining an end of said tube in said conduit ing and spacer sleeve adapted for use in connect independently of said conductor, said screw ing means of the above character is also com threads being out of cooperating screw-thread en bined in a novel manner with radio shielding gagement when said tube and conduit are assem means for high tension conductors whereby said 60 bled. sleeve may be readily installed or removed for 4. In apparatus ci the class described, a pair inspection or replacement in the field without the ‘of axially aligned radio shielding conduits, an aid of tools of any kind. Said spacer sleeve is electrical conductor ñxed in and insulated from also combined in a novel manner with yieldable each of said conduits, the end or" one of said means for eñecting an electrical connection be conductors projecting from one of said conduits tween two high tension conductors, the parts into the other of said conduits, means for secur being so constructed and assembled that no me ing said conduits together, a sleeve of insulating chanical connections to the spark plug ends of material removably mounted in said one conduit the shielding harness cables are necessitated. Although only a limited number of modifica for free angular movement and limited axial tions of the invention are illustrated and de movement relative thereto and slidably extend scribed, it is to be expressly understood that the ing into said other conduit, said sleeve loosely same is not limited thereto. The invention may surrounding said projecting end of the conductor be adapted to other applications, and the arrange and said axial movement being independent of ment and design of the parts may be varied with 75 said angular movement, and axially yieldable trically connecting radio shielded conductors of high tension electrical current whereby such con 2,405,881 7 means having abutting engagement with said con ductors for electrically connecting the same. 5. A radio shielded plug and socket connector for high tension electrical conductors comprising a metallic socket having an insulating lining and a conductor therein, a plug adapted to cooperate with said socket comprising a metallic conduit having an electrical conductor therein, said last named conductor projecting from said conduit, an insulating tube surrounding the projecting por tion of said last-named conductor and having a portion intermediate its ends disposed between said socket and conduit, means for removably securing said tube in said conduit for limited gas-tight manner, and axially yieldable conduct ing means interposed between said first-named conducting means and said conductor. 10. In apparatus of the class described, a me tallic socket lined with electrical insulating ma terial and having an electrical conductor there in, a metallic conduit, means for securing said socket and conduit together in axial alignment with each other, a tube of electrical insulating material removably mounted in said conduit and slidably extending into said socket, said tube hav ing an enlarged annular portion interposed be tween and in sealing relation with the adjacent ends of said conduit and socket, an insulated electrical conductor extending through said con duit into said tube, a hollow metallic member iill able means mounted in the bore of said tube in ing a portion of the bore in said tube adjacent abutting contact with said conductors for elec-_ the end of the latter within said socket, the closed trically connecting the latter, and means for se end oi said member being adjacent said insu curing said conduit to said socket. lated conductor, yieldable means interposed be 6. Insulated connector means for radio shielded 20 tween said member and insulated conductor for conductors of high tension electrical current Com electrically connecting the same, resilient means prising an .insulating tube having a differential in said member, a contact plunger slidably mount bore therein, a recessed conducting member ed in said member and interposed between said mounted in the larger portion of said bore in sub resilient means and said first-named conductor, stantially gas-tight relation with the walls there and cooperable means on said conduit and tube of, a spiral coil spring in the smaller portion of for removably retaining the end of said tube in said bore and having a portion thereof securely said conduit while permitting rotary and limited clamped between said member and an internal axial movements or said tube relative to said shoulder in said tube, plunger means slidable in conduit. the recess of said member and projecting from l1. In apparatus of the class described, a me axial movement relative thereto, and axially yield one end of said tube, means for limiting the move ment of the plunger means out of said tube, and resilient means in said recess for yieldably re sisting movement of said plunger means into said tube. 7. In apparatus of the class described, a tube of insulating material, a recessed electrically con ducting member mounted in the bore of said tube, tallic socket lined with electrical insulating ma terial and having an electrical conductor there in, a metallic conduit, means for securing said socket and conduit to each other, a tube com prising electrical insulating material removably mounted in said conduit and slidably extending yinto said socket, said tube having an enlarged external portion interposed between and in seal a coil spring in said bore having a portion at one end thereof securely clamped between the closed 40 ing relation with adjacent end portions of said end of said member and an internal shoulder in said tube, and a spring pressed contact plunger slidably mounted in the recess in said member. 8. In combination with a spark plug having a center electrode and a shielding barrel surround ing the upper end of said electrode, a metallic radio shielding conduit, an insulating tube ex tending from said conduit into said barrel, an enlarged annular portion or" said tube being dis posed between and engageable with the adjacent ends of said conduit and barrel, screw threads on said tube, screw threads in said conduit adapt ed to cooperate with said ñrst-named threads and normally disposed between the latter and said annular portion, whereby said tube may have limited axial movement relative to said conduit, an insulated conductor extending from said con duit into said tube, axially yieldable means mounted in said tube for electrically connecting said conductor and said electrode, and means en conduit and socket, an insulated electrical con ductor extending from said conduit into said tube, an electrically conducting member filling a por tion of the bore of said tube and being in sub ` stantially gas-tight relation with the walls there of, separate yieldable means at opposite ends of `said member for electrically connecting said mem ber with said conductors, and cooperable means `on said conduit and tube for removably retaining the end of said tube in said conduit while per mitting rotary and axial movements of said tube relative to said conduit. l2. Connector means for radio-shielded con ductors of high tension electrical current com prising an electrical insulating tube, a recessed conductor member mounted in the bore of said tube in substantially gas-tight relation with the walls thereof, resilient means secured within said ,bore and having electrical contact with a portion 60 of said member nearest one end of said tube, gaging said conduit and barrel for securely clamp ing said annular portion therebetween. plunger means slidable in the recess of said mem conductor against substantial movement relative thereto, a tube of insulating material extending a metallic conduit for receiving said one end of ber and projecting from the other end of said tube, means for limiting the movement of the 9. In connector means for radio-shielded con plunger means out of said member, resilient ductors of high tension electrical current, a ra means in said recess for yieldably resisting move 65 dio-shielding conduit for an insulated electrical ment of said plunger means into said member, conductor, means in said conduit for fixing said said tube, an insulated conductor extending from said conduit into said tube for engagement with into one end of said conduit and surrounding a projecting portion or" said conductor, cooperable 70 „said first-named resilient means, and means in ‘said conduit for ñxing said conductor against means formed integrally with said tube and con 'appreciable longitudinal movement relative to said duit for removably securing said tube in said con duit independently of said conductor, electrical conducting means sealing the bore of said tube adjacent the outer end thereof in a substantially i conduit. 13. In apparatus of the class described, a tube of electrical insulating material, an electrically 2,405,881 conducting member having a recess in one end thereof mounted in the bore of said tube in sub stantially gas-tight relation with the Walls there cf, yieldable means secured Within said bore and having electrical contact with the end of said member opposite said recess, a spring pressed contact plunger slidably mounted in said recess and projecting from said tube, a metallic conduit 10 lic conduit, an electrical insulating tube project ying from one end of said conduit, cooperable means integral with said conduit and tube for normally retaining an end of said tube in said `conduit While permitting rotational and limited axial movements of said tube relative to the con duit, said rotational and axial movements being independent of each other, a metallic socket for for receiving an end portion of said tube, an in -"receiving the projecting end of said tube, the lat sulated conductor extending from said conduit l0 ter having an enlarged annular portion thereof into said tube for electrical contact with said .interposed between adjacent surfaces of said con yieldable means, and means in said conduit for duit and socket, and means for securing said ccn '-_fixing said conductor against appreciable move Vduit and socket together for holding said surfaces ment relative to the conduit. in sealing engagement with Said enlarged por 14. In connector means for radio-shielded con tion. ductors of high tension electric current, a metal JAKOB R. FREI.