US2641663A - Electric switch - Google Patents

Description

June 9, 1953 A. w. KRIEGER 2,341,663

ELECTRIC SWITCH Filed July 28, 1949 2 sheets-sheet 1 I7/` MoMENTARY POSITION June 9, 1953 A. w. KRIEGER 2,641,663

. ELECTRIC SWITCH Filed July 28, 1949 2 Sheets-Sheet 2 Patented June 9, 1953 UNITED STATES PATENT OFFICE,

ELECTRIC SWITCH Alvin W. Krieger, Milwaukee, Wis.,'assignor to Cutler-Hammer, Inc., Milwaukee, Wis., a lcorporation of Delaware 7 Claims.

This invention relates to an electric switch, and more particularly to a switch adapted to selectively control a plurality of electric circuits; which, while not limited thereto, may be advantageously utilized in aircraft or the like where high capacity and a high degree of dependability and ruggedness in switches of small sizes are requisite.

A primary object is to provide a switch of the character described wherein opening and closure of its contacts is accomplished with a snap action not subject to teasing and wherein such snap action is secured by means not requiring lubrication.

Another object is to provide a switch of the character described wherein simultaneous closure of more than one of the circuits controlled is rendered impossible.

Another object is toprovide a switch of the character described affording various circuit controlling characteristics by the addition, and omission or substitution of a relatively small number of parts.

Another object is to provide an extremely simple and compact snap switch mechanism of the aforementioned character, and more particularly to improve the details of construction and assembly of the parts and the operation Of switch mechanisms affording the characteristics desired as hereinbefore described.

Another object is to provide in a switch of the character described, simplified spring means affording momentary positioning of the switch parts.

Other objects and advantages of the invention will hereinafter appear.

The accompanying drawings illustrate certain embodiments of the invention which will now be described, it being understood that the embodiments illustrated are susceptible of modication as to certain details of construction thereof without departing from the scope of the appended claims. l

In the drawings,

Figure l is a center line longitudinal sectional view of a double throw, two position switch constructed in accordancel with the invention and further illustrating means affording a momentary characteristic to one of the switch positions.

Fig. 2 is a top plan View of the switch illustrated in Fig. l with the mounting plate and operating means associated therewith removed to expose other switch parts.

Fig. 3 is a sectional View taken on the broken line 3.-3 of Fig. 2,V but with the switch parts in a .second or momentary position of the switch illustrated.

Fig. 4 islasectionalyiew taken on the broken line 4-4 of. Fig. 3.

Fig. 5 is a fragmentary sectional view of a, modified form of the switch affording a, single throw, two-position switch, the switch parts 4vbeing shown in the off position.

Fig. 6 is a side elevational View, with certain parts broken away for sake of clarity, illustrating a modification of the switch to afford fa double throw, three-position switch, and additionally illustrating means for rendering each of the two on positions momentary; the switch parts being shown in the olf position.

Fig. '7 is a top plan view of the switchy illusmuted in Fig. c but with the mounting plate and parts associated therewith removed to expose the other switch parts.

Fig. 8 is a fragmentary View similar to `that of Fig. '7 illustrating the switch parts in oneof their "on positions.

Referring to the drawings, the reference numeral ID designates a one-piece molded insulating base common to all of the Various formsof the switch to be hereinafter described, said '-b'ase being adapted to enclose and support the various switch parts. Base IG has a recess Illa opening to the upper surface thereof and to becovered by a mounting plate Il of well known form attached to the base as by rivets I2.

Referring primarily t0 Figs. 1 to 4, inclusive, illustrating a single pole, double throw, twoposition switch embodying the invention, the reference numeral I3 designates a pair ofstationary contacts preferably rigidly and permanently attached to the bottom wall of recess Il)2t andeach electrically connected to a terminal lug III'of well known form as by rivets I5. Also preferably rigidly and permanently attached to the bottom wall of recess Il!a is an electrically conductive U-shaped frame I E electrically connected to a centrally located common terminal lug I'I as by a rivet I8 (Fig. 4).

As best shown in Fig. 3, each of the upstanding arms of frame I6 is provided with a U-shaped slot I 5a extending downwardly from the top edge thereof to afford an open pivotal bearing for a toggle member i8 and more particularly for a plate-like portion thereof I9au having ears |91Y extending outwardly through the aforementioned slots 16a, as best shown in Figs. 2 and 4. As best shown in Figs. 2 and 3, said aforementioned ears I9b additionally provide a pivotal support for an electrically conductive rocking element Vor contactor 2D, the latter having openings V2l)a in the respective sides 2Gb thereof through which said ears I9b extend.

As best shown in Fig. 2, rocking .element '20 is formed of parallel side portions 2Gb positioned outside of the arms of frame I6 and pivotally supported at the center by member I9 and hence by frame I6 as hereinbefore described, and has 3 integrally formed connecting portions at each end thereof. Each of the aforementioned portions Ztc carries a contact 2l (Fig. 1) to cooperate with one of the aforedescribed stationary contacts i3.

A pair of helical over-center compression springs 22 (Fig. 3) are individually connected between each contact carrying end of rocking element 2o and plate lila of toggle member I9.

Member is additionally comprises an insulating portion it (Figs. l and 3) rigidly and permanently attached to plate lh in a well known manner. As best shown in Figs. 1 and 4, insulating portion ISC is recessed at the upper end thereof as at ltd to accommodate the lower end 23a of an operating lever of well known form and 'additionally is provided with a pin Ille extending transversely of said recess, the aforementioned lower end 23a being slotted as at 231 (Fig. l) to afford asliding linkage with pin lil@ and hence with toggle member i9. A helical compression spring 2li surrounding the lower portion 23a of lever 23 is adapted to abut pin ISe and bias toggle member l as a whole downwardly.

The upper end of operating lever Z3 extends through a suitable bushing attached to mountn ing plate i I in a well known manner, which bushing is provided with a transversely extending'lpin 25EL affording a pivotal support for lever E3.

As will be apparent, movement of operating lever 23 to and from its extreme positions will rock toggle member I9 about its centrally located pivotal point lab in frame It as aforedescribed, which rocking movement will in turn be trans mitted to contact carrying element 2i) through over-center springs 22 to rock element Eil in reverse directions selectively for engaging it through its contacts 2l with the stationary con- 4tacts I3 selectively. Oscillation of element 2Q in response to movement of toggle member I9 will, of course, occur each time the over-center springs 22 pass through center and will therefore result in engagement and disengagement of the contacts lwith a snap action which is substantially immune to teasing Moreover such snap action is achieved through the use and arrangement of parts heretofore described which require no lubrication and hence assure dependable operation in ambient temperature frequently encountered in aircraft or the like.

Similarly it will be apparent that the switch aiords a flow of electric current from one or the other of the outside terminal lugs I4 through one or the other of the stationary contacts I3 and its respective cooperating contact 2 I, according to the direction in which element 2Q is rocked. and thence through plate I 9 and frame i6 to common terminal lug I'I, wherefore the switch is adapted to selectively close one or the other of a plurality of controlled circuits. Moreover since contact carrying element Eil is centrally pivoted as at iSb it will be seen that engagement of element 2U with more than one contact I 3 at a time is rendered impossible. Furthermore over-center springs 22 bias the respective ends of element 20 in opposite directions in both positions of the switch.

.Additionally illustrated in Figs. 1 to 4, inclusive, are means to bias the switch to one of its circuit controlling positions thereby to render the remaining position momentary. As best shown in Figs. 3 and 4, such means take the form of a `pair of helical tension springs 26, the ends of which are removably connected between a pin 2l held by base ill transversely of one end of recess 50a over-center springs 22.

d and pin Ide.' respectively, said springs 25 being attached to pin Ide outside of toggle member I, as best shown in Fig. Springs it will., of course, be of sufficient strength to overcome :the bias of As will be apparent, the aforedescribed arrangement provides a simple method of rendering, according to selection, either circuit controlling position momentary only, which arrangement may easily and expe-` ditiously be altered or eliminated without alteration of the remainder of the switch structure.

In Fig. 5 is illustrated a modication of the switch heretofore described to provide a simple on, ofi snap acting switch for opening and closing a single electric circuit. The switch partel are essentially the as those hereinabove described, and where illustrated have been given like reierence numerals.

However, to afford the desired circuit controlling characteristics, terminal lug il' and one ci lthe terminal lugs Ifs have been omitted, the latter being replaced by a terminal lug 23 having a bus-like extension 28a for electrically connecting frame i6 through rivet it to the terminal portion 281. Also the cooperating contacts 2l and I3 at that end of the switch adjacent the terminal lug 2S, may, if desired, be omitted. As will be apparent, the aforedescribed modication may be simply accomplished to achieve the circuit controlling characteristics desired without altera- :tion of the remaining switch parts. Moreover the switch immediately described may be rendered momentary as to either of its positions by the same means heretofore described in connection with the embodiment of the invention. illustrated in Figs. l to Ll, inclusive. s

The embodiments shown in Figs. 6 to 8, nclusive, illustrate a further modification oi the switch to afford a single pole, double throw, three-post tion switch having an off position intermediate the two on positions. In :this form certain of the switch parts have been modified to accomplish the desired circuit controlling characteristics. All of the other Switch parts are the same as those hereinbeiore described and have been given like reference numerals.

Thus the three-position switch about to be described utilizes the same insulatingr base it, stationary contacts I3, terminal lug-s Ill and il, mounting plate l i and operating lever 23 with its associated parts. An electrically conductive U- shaped frameild is provided having a laterally extending ear i Ita (Fig. 7) at each corner thereof to afford pivotal bearings for a rocking element |26 to be hereinafter described. A pair of upstanding intermediate portions H51 of the contour best shown in Fig. 6 afford an interlock with and a guide for movement of a p`late-like portion H9 of a rocking toggle member IS, in other respects identical to the toggle member utilized in the switch embodiments hereinbefore described. As best shown in Fig. 7, portion It is notched on opposite side edges thereof to interlock with portions I Ib and to form pairs of outwardly eX- tending ears I I92L adapted to rest upon frame i I6 in the intermediate position of the switch as shown in Fig. G, or to afford selective pivotal points for said toggle member It when rocked to either of its extreme positions, one of such positions being shown in Fig. 8.

Electrically conductive rocking element or contactor B2i) is formed of parallel side portions |205' (Fig. 7) and integrally formed connecting portions I2@b at each end thereof. As best shown in Figs. 6 and 8, each of the aforemenm8413688VV tioned connecting: portions I20b carrie/sl at contact I2'I to cooperate-.with its` respective stationary contactA I3. Element I T is adapted" for pivotal movement about one or the =other of the pairs of ears IlIat at opposite ends of frame IIB, said pairs of ears Illia serving alternatelyu as pivotal-bearings for element |20 or asl stops to limit upward movement of the free end thereof.

The aforementioned movement of element |23 is responsive to reverse movements of toggle memberV I9 Aabout one or the other-of itsselective pivotal points afforded byv ears -I I9a as hereinbefore described, such movement'being-transmitted to element |20 by a pair of over-center helical compression springs 22 connectedY (as best shown in Fig. 7) individually between-opposite ends of element I 20 and portion IIB of toggle member I 9. As lis the case in the embodiments previously described, springs 22- upon going through center aord movement of` ele'- ment |23 with a snap action to eiect engagement and disengagement of the respective pairs of cooperating contacts. Similarly in either of the on positions, that is, when either of the pairs of contacts are engaged springs 22 bias the ends of element |25! in opposite directions, while when in the intermediate off position (Fig. 6) both springs 22 cooperate to bias element |20 upwardly against the stops afforded by ears Illia of frame ||6.

As will be apparent, the flow of electric current Ithrough either of the' circuits controlled will be substantially the same as that afforded bythe two-position, double throw switch hereinbefore described in either of the on positions, while provision of anr intermediate position in which neither of the pairs of contacts are engaged aords an off position for the switch in which both of the controlled circuits are interrupted.

It will similarly be apparent that the switch affords selective closure of one or the otherof the controlled circuits; Moreover, as'- best shown in Figs. 4 and 8, base I0 is provided with a pair of integrally formed lugs Il'Ib extending vupwardly and outwardly from the bottom and side walls of recess ma to afford a centrally located auxiliary or emergency pivotal point'for element |20 in the three-position form ofv the switch to render impossible simultaneous l engagement of both pairs of cooperating contacts. For example, should one pair of cooperating contacts stick or weld upon engagement, movement of toggle member I9 to its opposite extreme position would cause the bottom edges of element |23 to be driven against lugs Ib to prevent closure of the other pair of cooperating contacts or to pry the welded pair of contacts apart. It will therefore be seen that closure of both of the controlled circuits simultaneously is rendered impossible.

Similarly to the two-position form of the switch previously described, the three-position form illustrated may, if desired; be'additionally provided with spring means similar to those heretofore described to render any one or more of the circuit controlling positions of the switch momentary. In the switch shown in Figs. 6 to 8, inclusive, two pairs of springs -29 are removably connected respectively between pins 21 and pin |9e as hereinbefore described, to bias toggle member I9 to its intermediate or oi position, thus rendering each of the on positions momentary only. As will be apparent, either one of `said pairs of springs-could be omitted thus to. render; only one f of there. "011 positionsf moimentary, or the relatively stronger pair? of springs-'utilized "in the i two-position form. of `the switch couldbe used tobias member |9 to one or thefother of'its extremepositions to render one offthe on and the intermediateiorY off position both momentary. Thus it will' be seen that the immediately aforedescribed circuit controlling characteristics may be simply and expeditiously Varied without disturbance of the remainder of-the switch parts, the means provided being easyto assemble and relatively simple-'to' manufacture.

The mounting plates II common to all forms off'the Vswitch may be provided with self-locking nuts 13D-fof Well known form (Fig. l) for attachment of'f the switches to suitable supporting structure. Additionally each of the switches may (as illustrated in Fig. 1) be provided with a dust boot assembly of the type disclosed in my copending application lS.' N. 64,077, filed December 8, 1948, now abandoned, and comprising a dust boot 3| and clamping means therefor 32. An insulating gasket 33 (Fig. 3) is also interposed between the mounting plate II and the top` surface of base It to electrically insulate the former fromvthe switch parts and to aid in rendering the switches dust-proof.

I claim: y

l. A multi-position snap acting switch adapted to selectively controla plurality of electric circuits comprising, in combination, a pair of cooperating contacts' for each electric circuit controlled,v a rocking element having a plurality of pivotal points and carrying at each of its ends one contact of each of said pairsof contacts, snap acting means for oscillating said element alternately about one or the other of its pivotal points, said means comprising a toggle member having selective pivotal points and a pair' of over-center springs individually connected'between opposite ends or" said element and said toggle member for selective movement of one orthe'other of said contact carrying ends oi said element into and out of engagement with its'cocperating contact in response to reverse movements of said toggle member about its pivotal points selectively, said over-center sprin'gsbiasing the respective ends of said element in opposite directions upon engagement of any' of said pairs of contacts.

2. A multi-position snap acting-switch adapted to selectively 'control a plurality of electric circuits comprising, in'combination, a pair of cooperating contacts for each electric circuit controlled, an.' element having 'a plurality of pivotal points and carrying at each of its ends Vone contactof each ofsaid pairs of contacts, snap acting means for oscillating said element alternately aboutkone orthe rother of its pivotal points, a frame` having* plural parts each affording a pivotal bearingor said'element or alternatively affording a stop'to limit movement of said element aboutV the other of said pivotal points, said snap. acting. means comprising a toggle member havingselective pivotal points and .a pair of over-center springs individually connected between-opposite ends of said element and said toggle -member for selective movement of one or the other of said. contact carrying ends of said .element intoand vout. of engagement with its cooperating contact inv response to reverse.V movements Iof .said toggle Vmember about its; pivotal-points selectively, said over-center springs biasing the respective ends of said element in opposite directions upon engagement of any of said pairs of contacts and biasing said aforementioned element vends in the same direction upon disengagement of all of said pairs oi contacts by movement of said snap acting means to a position intermediate its extreme positions. f

3. A multi-position snap acting switch adapted to selectively control a plurality of electric circuits comprising, in Combination, a pair of cooperating contacts for each electric circuit controlled, a rocking element having a plurality of pivotal points and carrying at each of its ends one contact of each of said pairs of contacts, snap acting means for oscillating said element alternately about one or the other of its pivotal points, said means comprising a toggle member having selective pivotal points a pair of over-center serings individually connected between opposite ends of said element and said tog; gle member for selective movement of one or the ther of said contact carrying ends cf said elerient into and out oi engagement with its co operating contact in response to reverse movements of saio toggle member about its pivotal points selectively, said overcenter springs biasing the respective ends of said element in op posite directions upon engagement of any of said pairs of contacts, and spring means connected to said toggle member biasing said snap acting means to render at least one of its circuit controlling positions momentary.

fi. A snap acting switch comprising, in comn bination, a rocking element having a plurality of longitudinally spaced pairs of supports and having at one end a contact portion, a current carrying support for said. element upon which said element has pivotal bearing, a stationary contact to be engaged disengaged by said contact of said element upon reverse pivotal movements of said element, a rocking toggle member, springs providing an operating connection between said toggle member and said element, a pair of wiring terminal elements respectively electrically connected with said sta tionary contact current carrying sup port.

5. A multi-position snap acting switch adapted to selectively control a plurality of electric circuits comprising, in combination, a pair of cooperating contacts ior each electric circuit con-y trolled, a rocking element pivotable at either end carrying at each of its ends one contact of each of said pairs of contacts, snap acting means for oscillating said element alternately about one or the other oi its pivotal points, a frame having plural parts each aiioroing a pivotal bearing for said element or alternatively affording a stop to limit movement of said element about the other of said `pivotal points, said snap acting means comprising a rocking toggle member having selective pivotal points and a pair of over-center springs individually connected between opposite ends of said element and said toggle member for selective movement of one or the other of said contact carrying ends of said element into and out of engagement with its cooperating contact in response to reverse movements of said toggle member about its pivotal points selectively, said over-center springs biasing the respective ends of said element in opposite directions upon engagement oi any of said pairs of contacts, and an auxiliary centrally located pivotal point for said element to render simultaneous engagement of more than one of said pairs of contacts impossible.

t 6. A multi-position snap acting switchV adapted to selectively control a plurality of electric circuits comprising, in combination, an insulating base for enclosing and supporting the switch parte, a pair of cooperating contacts for each electric circuit controlled, a plurality of terminal lugs attached to said insulating base exteriorly thereof, pairs of contacts comprising a stationary contact rigidly and permanently attached to said insulating base and to one of said terminal lugs, an electrically conductive rocking element pivotable at either end and carrying at each of its ends one contact of each of said pairs of contacts, snap acting means for oscillating said element alternately about one or the other of its pivotal points, an electrically conductive frame attached to said base and to a common terminal lug and having plural parts each affording a pivotal bearing for said element or alternatively aiording a stop to limit movement of said element about the other oi said pivotal points, said snap acting means comprising a rocking toggle member roclringly supported by said frame and having selective pivotal points thereon, and a pair of over-center springs individually connected between opposite ends of said element and said toggle member for selective movement of one or the other of said contact carrying ends of said element into and out of engagement with cooperating stationary conttact in response to reverse movements o1" said toggle member about its pivotal points selectively, said overcenter springs biasing the respective ends of said element in opposite directions upon engagement of any of said pairs of contacts and biasing said aforementioned element ends in the same direction upon disengagement of all of said pairs of contacts by movement of said snap acting means to an'intermediate position, said insulating base having projections affording centrally located auxiliary pivotal point for said element to render simultaneous engagement of more than one of pairs of contacts impossible.

7. A three position snap acting switch comprising, in combination, a movable current carrying element having contact portions at opposite ends thereof, stationary contacts positioned for alternative engagement by said movable element, a movable toggle member, compression springs positioned between opposite ends of said toggle member and corresponding contact ends of said movable element, and a current carrying support in electrical contact with said movable element and affording for selective movements of said movable element and said toggle member a plurality o1" pivotal axes, said switch being convertible to a two position snap acting switch by limiting said movable element and said toggle member to movement about a single axis.

ALVIN W. KRIEGER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 435,093 Herrick Aug. 26, 1890 1,538,938 Hulse May 26, 1925 l,l56,338 Meuer 1 Apr. 17, 1928 1,329,037 Bobroi Oct. 27, 1931 2,362,906 Krieger Nov. 24, 1936 2,374,868 Krieger May l, 1945 FOREIGN PATENTS Number Country Date 28,120 Great Britain Dec. 24, 1908

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