US 2658130 A
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Description (OCR text may contain errors)
F'atented Nov. 3, 1953 EN? QEEICE:
TERMINALv Kenneth-iEi-Bondurent, Andersonalnd assgignori toiGeneralv MotorsCorporation petroit, Mich, a-co porati n.ofrDielaw re'.
Application October- 26, 1951-, Serial No.- 253,262? 5. Glaims:= (Cl. 200-168) This? invention relates. to. terminals ands a; method. r of mounting; the terminal; in an were turedwallof a casing; Terminals ofithisqch irr acter have to vpass; through aitwall fQI'r fas inglinsuch a manner, as -:to make. laisealedijeint' With ,the waili Heretofore it has.- been; the practicertoi embed a ,Vterminal, or; terminals-in: an iinsulatineg losure; which. closes. one 1 end: of a; casin and: so;- that portions of: the: terminals; extend; into the 1 a e to form stationary contacts to be,bridged;by. a movable; contact and; portions of: the termina extendmearwardwaof;the;closureand:are ad pteri to have: electrical, conductorscon-nected; to; These electrical. connections; are; commonlyi br jected to deterioration: particularly when, he connections, are. subjected, to various moisture conditions; containing sa-lt.
In many instances the; electricali apparatus; of. h yp nder consideration hasa: ylindrical metal 7, case the rear rims 1. ofv which; have; projecting spacedtangsthatgare bentgover against the outer-face of the-closur to :hold tthenl te in as-i sembledr relation; with; the case; In", such; elefifi trical apparatus the.,closurewarrifistthroughgter minals having one, end within: the; housing 1 an having the other extending outside-the-casing: which are elec ri ally; connected with; he: an: ct rs.-; v In order to protect: the; con acts with-, in the. housing; and the connections. outside: the; housing 1 between the terminal nds the: OIIdIlQ: tor from deteriorations: or; corrosion, due to; ex: posure. to. atmosphe e ontainin sa t 1: the: r ar: end of-;cas ing was covereplaor xpottedawith a body, of insulating material; about the: casin ter. minals; and cables. Thisjpracticev of; enclosing the connections with, a; body of; insulating, mas terial isobviously unhandyi-and costlyanehtheres foreobjectionable.
It is the purpose of the present invention; to; provide aclosure and ;ter,minal construction and arrangement suitable for; use: with? av casing; which must be sealed against entranceiof: mois;-.- ture between the; terminal and closure; into-J the casing; and at the, same timeform: amoisture: seal about the fixedconnection between; the: tenminaland the cable outside thecasingu It is aiurther purposeof theL invention: to provide a novel method of; securing a a; terminal; to r a closure 'fora casing which must; be; sealed; against. entrance of moisture and; to prov-idea seal about: the connection.
Further-objectsand advantages of the: present inventionwill; be apparent; from. the, following: description,- reference: being hada to the accomsl 2-1:- panying drawings wherein; a preferred embodi-r. IHGIItZOfTthS. presentginvention is; clearly shown.
In \the: drawing: Figs 111s. at side, elevational'viewiof a switch,
apparatus having the-electricalnonneetionsbe:
tween the terminal post: and the. cable seal against; entranceof moisture; portion, of 1' the switch being shown iinxsection;
Fiig. v 2.;isian exploded view of: a 1 modifrede form showing details. of each. ofrtheseparate; parts,
shown: in Fig.1 1: andiillustratesia; methodioi as: sembling 5 the, parts,
Fig, 3:issa side view: of; a; yieldablerbushin used in the present invention.
Referring to Eig. 1;ofthe drawings;- illiaclesignatesqalcasingvof anieleetr-ic. switch,- suchas a starting.=, switch adapteditocbe mountedwon an instrument panel .or; suitable. support of an aue tomotivee vehicle. The; bore 21 of the. casing; is enlarged at 22: to-iprovidev a; continuous; abut.- ment or shoulders 2 3: portion; of: the. casing is. provided with a, plu-. rality.ofr'spaced tongues or tangs25li Aigasket' 25: of :noneporous zyieltiable material .snchias rube her or other suitable yielclablematerialis posi tionediwithi-n:-theenlarged. portionof the case ing; seatingson;thea abutment. 23;. Thegaskett25i is: heldiin place by a; body 261' ofv insulating material having: anva-nnularbead: 21; onitsinner: face, A; pressure plate; 28:; abuts. the outer face; ofgtheebody ziiu The; plate-28; body: 2S;and*thegasket 2.5;1are held? firmlyrini p1ace=w-ithin the,
casing 20?: byrbending: over. the; tangsi 25'. against the router facerof the plate 28;:
It;.will': beaunderstood that. when a thectangsv 2.4
are; hentgoverntheplate 28: the bead 2l'wi11 be forcecli into the; gasket 25': forming an annular, depression. in; the; gasket 25; and the gasket will bee compressed:- between, the abutment or shoul (181323; and the-inner fa'ce of the boclyt-ztrto .form a: fluid; tight: seal: thereau. to prevent moisture,
whichzmay: creep: past ithe periphery of the-body. I
215;; and": the 1: inner; walls; of r the. enlarged portion 22;; .from entering-into theibore 2'1:
Theabodylfi ise provided-iwitha. pair of coun- The rim: of the enlarged ductor having a layer of insulation. Thi insulation is stripped from the end portion All of the conductor which is staked or otherwise fastened into the smaller bore so as to seal the conductor to the post. Two staking operations are required one to seal and the other to form an electric connection.
The lower end of the terminal post 35 is encompassed by a sleeve 4| of rubber-like resilient compressible insulating material. The sleeve ll may be constructed of natural rubbers, any known synthetic rubber, or suitable plastics which offer resistance to deterioration by oil or various moisture conditions containing salt. The sleeve 4| is threaded on the cable and over the lower end of the terminal posts as viewed in Fig. 2. The sleeve is slipped over the cable 39 and post 35 to form a tight seal. This is facilitated by use of a suitable lubricant. The lower end of the bushing is slightly larger than the bore of the sleeve fill so that it provides a good seal.
Referring to Fig. 3 the upper end of the sleeve has a head lla having a beveled portion 42 so that it will register with the beveled seat 32 in the body 26. The upper end of the bore in the sleeve is restricted as at 43 that will snap into the groove 31 formed on the terminal post The lower end of the bore will fit snugly over the lower end of the terminal and also grip the portion of the insulation of the cable 39. The lower end of the sleeve is tapered so as to facilitate entrance into the Opening 4-5 in the plate 28 surrounded by flanges 45 extending below the lower face of the plate 28.
In assembling the parts 23, 26, 2t and subassembly including the terminal post 35, cable 39 and sleeve the operation may be carried out as follows: The gasket and body are placed within the enlarged portion 22 of the casing MI. The subassembly including the post 35, cable 39 and sleeve 4! is then assembled so that the contact portion is passed through the opening 39 until the flange or roller 36 engages the shoulder. It will be noted the contact post 35 extends beyond the inner face of the body 26. The plate is slipped over the cables 39 and then by suitable fixtures, not shown, support the housing as and by movable member, not shown. The plate 28 is moved into the enlarged portion of the casing until gasket is sufliciently com-pressed to form a fluid-tight seal between it and the abutment 23 and between the gasket and the body 26. While the gasket is being compressed the collar 3i: will engage the shoulder 3| and the sleeve ll will be compressed between the collar 36 and the plate 28. Since the rubber sleeve cannot expand radially outward between the closure and terminal and between the sleeves of the plate and the terminals the sleeve within the flanges will be placed under considerable pressure forcing the sleeve in sealing engagement with the cable below the end of the terminals. Thus an effective seal is accomplished so that no moisture, air or foreign matter can pass along the inner surface of the sleeve to the connection between the cable and terminal post. Such a sealed connection will hold against either vacuum or pressure within reasonable limits.
It will be apparent that the invention above described, while providing a seal between the cable and terminal and between the flange and bushing and between the bushing and closure and also the proper insulation between the terminal and the plate it also allows for a certain amount of flexibility between the sleeve and the cable.
While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.
What is claimed is as follows:
1. In an electrical unit comprising; a casing having a continuous internal abutment; a body of insulating material; a ring of yieldable material under compression disposed between the abutment and the body, said body having at least one counterbored opening therein to provide a shoulder; a terminal having one end extending through the opening and having a collar engaging the shoulder the other end of the terminal providing spaces below the collar between the terminal and the body; a cable having an electrical connection with said other end of terminal; a plate having a sleeve portion separated from said other end of the terminal and the cable by a substantial clearance; a flanged bushing of yieldable compressed material disposed about said other end of the terminal and the adjacent end of the cable, said bushing completely filling the spaces between the terminal and body and the spaces between the sleeve of the plat and the terminal; and means including associated portions of the casing to associate the plate with the casing and for keeping the yieldable ring and the bushing under compression and also for maintaining the lower end of the bushing in sealing engagement with the cable.
2. In an electric switch construction, the combination of a tubular casing having an enlarged portion at one end to provide a continuous internal abutment; a movable contact supported within the casing; a sealing gasket adjacent the abutment; a body of insulating material having a pair of stepped bores to provide internal shoulders; a conducting element for each bore, said elements extending through the bores and havin an end forming switch contacts adapted to be engaged by the movable contact and having a radially extending annular flange positioned in the larger portion of their respective bores and having the other end provided with a socket; a cable extending into each socket and electrically to their respective element; a bushing of resilient non-porous insulating material surrounding each socket end of the elements and a portion of the cables, said bushings having a head at one end extending into the larger portion of stepped opening of the body; a plate having a pair of flanged openings to receive the other ends of the bushing; and means including portions of the casing engaging the plate for compressing the gasket into scaling engagement with the abutment and the body and for compressing both bushings in sealing relation against both elements and cables to prevent fluid creepage to said electrical connections.
3. In a switch ccnstruction the combination of a tubular casing having an internal continuous abutment; a body of insulating material located within the casing; a gasket member of compressed yieldable material disposed between the abutment and body; a terminal associated with the body and having one end exposed beyond the inner face of the body and having the other end provided with a socket which is exposed beyond the outer face of the body; a cable having one end encompassed by the socket end of the terminal and electrically connected to the terminal within the confines of the socket; a plate located within the housing, said plate providing at its outer face sleeve-like flanges, a bushing member of yieldable material highly compressed surrounding the socket portion of the terminals and portions of the cable and completely filling the space between the flange and the terminal and causing one end of the bushings to grip the cables to prevent fluid creepage to said electrical connection; and means including associated Portions of the housing'ior holding the plate in position and for keeping all of the yieldable members under compression 4. In a sealing arrangement for an electrical apparatus comprising a tubular casing having an internal continuous abutment; a body of insulating material located within the casing; a resilient gasket disposed between the abutment and body; a terminal associated with the body and having one end exposed at the inner face of the body and having the Other end exposed beyond the outer face of the body, said body being formed with tapered seat surrounding the terminal; an insulated conducting wire electrically connected to the terminal; a plate located within the casing having a flange opening; a grommet surrounding the other end of the terminal and portions of the insulated wire, said grommet being made of rubber-like material with one end w forming an enlarged seating portion and the other end forming a tapered sleeve portion, there being an annular shoulder between the ends of the said grommet, said tapered portion passing through the flanged opening and the enlarged portion being seatable on the edge of the opening in said plate and also extending into said seat of the body surrounding said terminal; and mean including associated parts of the casing for holding the plate in position and also to deform the gasket and the grommet to produce a sealing relationship between the gasket, the abutment, and the body, and also a sealing relationship between the grommet, the body, the terminal, and the insulated wire.
5. In a sealing arrangement for an electrical apparatus comprising a tubular casing having an internal continuous abutment; a body of insulating material having a stepped bore to provide an internal seat located within the casing; a resilient gasket disposed between the abutment and the body; a terminal extending through the bore of the body and having one end exposed within the casing and having the other end exposed outside the body, said terminal having a collar contacting the seat in the body; an insulated conducting wire electrically connected to the terminal; a plate located within the casing having a flanged opening; a flanged grommet surrounding the other end of the terminal and portions of the insulated wire, said grommet being made of yieldable rubber-like material and having the flange seated against the collar of the terminal and having portions passing through the flanged opening of the plate; and means to draw up said plate in firm engagement with the body and also to deform the gasket and the grommet to produce a sealing relationship between the gasket, the abutment, and the body, and also a sealing relationship between the grommet, the body, the terminal, and the insulated wire.
KENNETH E. BONDURANT.
References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,984,275 Mallory Dec. 11, 1934 2,574,698 Hall Nov. 13, 1951