US2681962A

US2681962A - Combined circuit breaker and switch

Info

Publication number: US2681962A
Application number: US234775A
Authority: US
Inventors: Sundt Edward Victor
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-07-02
Filing date: 1951-07-02
Publication date: 1954-06-22
Anticipated expiration: 1971-06-22

Description

June 22, 1954 E V, SUNDT COMBINED CIRCUIT BREAKER AND SWITCH Filed July 2, 1951 van? VII/Ig..

Patented June 22, 1954 UNITED STATES PATENT OFFICE COMBINED CIRCUIT BREAKER AND SWITCH Edward Victor Sundt, Chicago, Ill.

Application July 2, 1951, Serial No. 234,775

This invention relates to a combined circuit breaker and switch.

The principal object of this invention is to provide an improved combined circuit breaker and switch embodying a Vsingle switch means for use in electrical circuits wherein the switch means may be operated automatically and freely upon the occurrence of a circuit overload condition, wherein manually operated means may operate the switch means to open and close the circuit as desired, wherein the manually operated means does not interfere with the opening of the switch means upon the occurrence of an overload condition, which is simple in construction and foolproof in operation, which is inexpensive to manufacture and install, and which has a long use ful life.

The combined circuit breaker and switch of this invention has many uses, particularly in low voltage circuits such as found in the automotive eld and in ranges up to about 115 volts A. C. Brieiiy, it includes an insulating base having stationary contacts carried thereby and a snap-acting bimetallic element supported by the base and carrying contacts for normally engaging the stationary contacts to complete an electric circuit through the bimetallic element. The bimetallic element operates when the temperature thereof increases to a predetermined value upon the occurrence of an overload condition to separate the contacts for opening the electric circuit. A lever is pivotally carried by the basefand has means thereon for engaging the bimetallic element when the lever is movedto one of two positions, an ofi position, to separate the contacts and open the electric circuit. When the lever is in the other position, the on position, it does not interfere with the operation of the bimetallic element. A cover is also provided for the base. The lever may be one of a pair of toggle levers, the other toggle lever being pivotally carried by the cover and extending therethrough to serve as a handle to be man-` ually manipulated for opening and closing the contacts forming the switch means.

Preferably, the switch means includes two pairs of contacts so that deterioration of the contacts in use is maintained at a minimum. The stationary contacts are preferably formed on posts extending through the base and these posts in addition to forming electrical connections also may form mounting means for the switch unit.

Further objects of this invention reside in the details of construction of the combined circuit ture-responsive, bimetallic element I8.

breaker and switch and the cooperative relationships between the component parts thereof.

Other objects and advantages of this invention will become apparent to those skilled in the art upon reference tothe accompanying speciijlcation, claims and drawing, in which:

Fig. 1 is a vertical sectional view through the combined circuit breaker and switch of this invention showing the same in off position;

Fig. 2 is a view similar to Fig. 1 but showing the combined circuit breaker and switch in on position with the electric circuit closed;

Fig. 3 is a view similar to Fig. 2 showing the combined circuit breaker and switch in on position but with the contacts separated due to the existence of an overload condition in the electric circuit;

Fig. 4 is a vertical sectional View taken substantially along the line 4--4 of Fig. 1;

Fig. 5 is a horizontal sectional View taken substantially along the line 5--5` of Fig. 1;

Fig. 6 is an exploded perspective View of the snap-acting bimetallic element and one of the toggle levers associated therewith.

The combined circuit breaker and switch of this invention is generally designated at I0. It includes a base II made of suitable electrical insulating material such as molded Bakelite or the like. Secured in the base II, preferably during the molding operation, are a pair of posts I2 having shoulders I3 and I4 and extension I5 for iirmly securing the posts in the base II.

The outer ends of the posts are preferably screwthreaded for the purpose of making electrical connections thereto and for mounting the unit. The inner ends of the posts I 2 are provided with stationary contacts IB. In this respect the contacts I6 may be formed of suitable contact material and secured to the ends of the posts as by welding or the like.

The combined circuit breaker and switch of this invention utilizes a snap-acting, tempera- This bimetallic element I8 is elongated and is provided with a pair of longitudinally extending slits I9 to form a central leg 2i] and a pair of outer legs 2I. The center leg 26 is slightly longer than the outer legs 2| and is also crowned to provide snap-acting characteristics to the bimetallic element. A pair of contacts made of suitable contact material are secured to the bimetallic element adjacent the ends thereof as by welding or the like. The movable contacts 22 are adapted to engage the stationary contacts IE to complete an electric circuit through the bimetallic element I8 across the contact posts I2.

The central leg 2D of the bimetallic element I8 is centrally provided with a rectangular hole 24 for receiving a rectangular post 25 having an enlarged head 26. The post 25 is adjustably received in a rectangular hole 2'! in the base II, the post being received therein by a force nt. In this respect the post Z is provided with serrations for assisting 'in maintaining the post `in proper position in the'hole 21. A spring 28 vencompasses the post and extends between the bimetallic element I`8 and the base II for maintaining the bimetallic elementagainst.theehlarged head 26 of the post. "Thus, the post25 and the spring 28 operate to mount.:the :bimetallic element I8 on the base II. Whenthe bimetallic element is being so mounted, kthe post25"is"in serted into the base I! to a predeterminedpoint properly to position the bimetallic element I8 for y.the purpose .of Calibrating. -the same .with respect to temperature.

When theicondition .ofthe electric .circuit is normal, .the .temperature .of the vbimetallic element IS is such .that theicontactsn22. .carried thereby engage the stationarycontacts I5 .for completing .the electric. circuit as illustratedfin Fig. 2; When,.however, -an .overload condition occurs inthe electriccircuit, thetemperatureof the bimetallic element .I8 increases. and when the' temperaturedncreases to apredetermined value determined .by thecalibration of the i-unit, then the bimetallic element snaps to. the position illustrated in Fig.- 3.for. .separating the-.contacts 22 :fromV the stationarycontacts I3 This breaks the electric circuit. .Whenl .the temperaturev of the bimetallic'element I8 decreasesto a precietermined lower value, thebimetallic elementthen snaps back Yto `the-.position illustrated .in Fig. 2 forre-closing .the contacts. the. .particu1ar arrangement 'illustrated -here in .the .drawingfthe bimetallicelement will continuato cycleso long as "the overload condition exists in the .circuit The substantially rectangular hole in the central leg 20. in the bimetallic element'lland.thereotangularpostZB .operate Ato prevent .rotation of the bimetallic element I3 so thatthe contacts22 and I6 -are maintained. in alignment.

.A vcover 3| is suitably securedto thefbase II and restsagainst a shoulder' .3c provided onthe peripheryof the base H."`.The.cover 3I .may be secured .tothe base II as by 'crimpingthefsame thereto.' On opposite sides ofthe centralpostl the base I l is provided with a pai-r of.recesses..32.

` A U-shap'ed lever 34 overlies bimetallic .ele, ment 18 and has its ends 35 received inthe recesees32 forthe purpose of pivotally mounting thelever 34cnth`e base I I. The lever v'34.is pro vided with a Apair `of surfaces 36 for'lengaging the Iupper surface offthe base II to limit pivotal movement in one direction offthefleverf34. A`It is also provided witha pair fof. surfaces 31 `for engaging the 'upper'.'surface of :thefbase I I lfor permitting .limitedsmovement thereof'.1in-theoppositcfdfirection. fAs .shown in .1i,thc` sure face 3l' limits the pivotal movement of the lever 34..in. one direction and-as shown in Figs. 2`and. 3 thewasurface .limits the pivotalmovernent in the .opposite direction. Thus, `the lcveri34ris pivotally..mounted .for movement between two positions. .Thelever-34 also carries a pair off-pins 38 belowthe vbimetallic.element Ivx which .are adaptedto engage .the ,i under sides .of .the outer legs 2`I "of the bimetallic element I8. When the lever34 is .in the position illustrated. in Figs. 2

l'22 thereof away from the stationary contacts I6.

Thus, when the lever 34 is in the position illusfifti'ated in Fig. l, the contacts are separated and .y .the..circuit opened .independently of overload conditions in the circuit. The top of the lever J34wis-:providedvwith a pair of projections 39 and a recess 40 therebetween which are utilized for thepurposeof moving the lever 34 between the two'xpo'sitions.

The lever 34 forms one lever of a pair of toggle levers, the-.other toggle lever .being-designatcdat 42. This toggle lever `42 is provided withasphericalsurface 43 .whichfengages a .socket .44 .formed inthercover 3I..A..plate 45 .alsohaving a socket 48.is-.secured to the .cover 3| by any .suitable means suchasrivets 41. The .sockets 44.and 4.6 and thespherical .surface ..43 .operate pivotally. to mountthe ktoggle`lever.42. in the .cover 3I. The toggle. lever.42 extendsthrcugh thecoveril .and the. .outenend .thereof .seri/'esas ahandle .to..be manually manipulated. The toggle lever.42..is.internally .provided with abore .48.in which` is slidably .mounted plunger .49 .which is. spring pressed toward. the vtoggle lever 34 .bymeansof a .spring .5.0 within .the bore .48. .The spring pressed .plunger 49 of. thetoggle .lever .42.. engages in the recess 48 between the projections .318 ,to form an -operatingconnection between .the`v two toggle levers .34 and .42. l

.When the toggle levers .34 .and A4.2 .are in the position illustrated in Fig. 1,.that is, l.the off positionfthey .are maintained in that position by the spring .fwacting on .the plunger vII!! and.` the movable-.contacts22 are separated fromthe ystationary. contacts I 6 .for .maintaining the electric .circuitiopen .When,y however, the toggle levers 34 .and .42 :are moved to the position .illustrated in V2, .that `is,.the on position, they are maintainedin thatposition bythe spring 50. `acting. on .the plungerf49 .and .the `pins V38. are .moved away-romthe bimetallic elementl3sothat the movable contacts l.22 engage-the stationarycontacts YI6..tc.cornplete .the electriccircuit. Iincw an overload condition. should occurinth'e-z-electric` circuit, the temperature of .the bimetallic element yHzis :increased to-separate the movable contacts 22-.from the stationary contacts I.6,a'as illustrated -in Fig. .3., to .open .the electric circuit.

Thus,- the toggle levers34 and Y42 cooperating with .the .bimetallic .element `Itioperate "a manually operated switch-;foropeningand closing. the `electric Vcircuit 4as desired, this @being accomplished by,moving the toggle levers between the foi land fonapositions When, however, the toggle levers 34 and `42 :are moved to-the .fon .position, then the bimetallic element 18 operates vfreelyand `automatically as a circuit breaker` to `open .and -close the Yelectric circuit in accordance with overload .conditionstherein `While .for-.purposes of illustration one .form of this..invention.has been. disclosed, otherforms thereof may becomeapparent .to .those lskilled in the art upon reference to this disclosure and. tahereforathisA invention` is to be` limited only by thescope of' the, appended claims.

`tact to complete an electric circuit through the bimetallic element, said snap acting bimetallic element operating when the temperature thereof increases to a predetermined value to separate the contacts for opening the electric circuit and operating when the temperature thereof decreases to a predetermined value to engage the contacts for closing the electric circuit, and a pair of spring biased togglelevers including a lever pivotally carried by the base and movable between two positions and maintained at either of said two positions and having means thereon free from the bimetallic element when the lever is in one position to permit free operation of the bimetallic element but engaging the bimetallic element when the lever is in the other posivtion'to separate the contacts and open the electric circuit.

2. A combined circuit breaker and switch comprising, an insulating base, a stationary contact carried by the base, a snap acting bimetallic element supported'by the `base and carrying a contact for normally engaging the stationary contact to complete an electric circuit through the bimetallic element, said snap acting bimetallic element operating when the temperature thereof increases to a predetermined value to separate the contacts for opening the electric circuit and operating when the temperature thereof decreases to a predetermined value to engage the contacts for closing the electric circuit, a cover carried by the base, and a pair of spring biased toggle levers movable between two positions and maintained at either or" said two positions, one of the levers being pivotally carried' by the cover and extending therethrough to serve as a handle to bemanually manipulated, ,and the other lever being pivotally carried by the base and having means thereon free from the bimetallic element when the toggle levers are in one position to permit free operation of the bimetallic element but engaging the bimetallic element when the toggle levers are in the other position to separate the contactsv and open the electric circuit.

3. A combined circuit breaker and switch comprising, an insulating base, a stationary contact carried by the base, a snap acting bimetallic element supported by the base and carrying a Contact for normally engaging the stationary Y contact to complete an electric circuit through the bimetallic element, said snap acting bimetallic element operating when the temperature thereof increases to a predetermined value to separate the contacts for opening the electric circuit, a cover carried by the base, and a pair of 'toggle levers including a rst lever pivotally carried by the cover and extending therethrough with its outer end serving as a handle to be manually manipulated and with its inner end provided with a spring pressed plunger, and a second lever pivotally carried by the base and engaged by the spring pressed plunger and having means thereon for engagging the bimetallic element when the toggle levers are moved to one positionto separate the contacts .and open the electric circuit.

4. A combined circuit breaker and switch comprising, an insulating base, a stationary contact carried by the base, a snap acting bimetallic element supported by the base and carrying a contact for normally engaging the stationary contact to complete an electric circuit through the bimetallic element, said snap acting bimetallic element operating when the temperature thereof increases to a predetermined value to separate the contacts for opening the electric circuit and operating when the temperature thereof decreases to a predetermined value to engage the contacts for opening the electric circuit, a cover carried by the base, and a pair or toggle levers movable between two positions and including .a first lever pivotally carried by the cover and extending therethrough with its outer end serving as a handle to be manually manipulated and with its inner end provided with a spring pressed plunger, and a second lever pivotally carried by the base and engaged by the spring pressed plunger and having means thereon free from the bimetallic element when the toggle levers are in one position to permit free operation of the bimetallic element but engaging the bimetallic element when the toggle levers are in the other vposition to separate the contacts and open the electric circuit.

5. A combined circuit breaker and switch comprising, an insulating base, a pair of stationary contacts carried by the base, a snap acting bimetallic element having a pair of contacts for normally engaging the stationary contacts to complete an electric circuit through the bimetallic element, means between the contacts of the bimetallic element for supporting the bimetallic element on the base, said snap acting bimetallic element operating when the temperature thereof increases to a predetermined value to separate the contacts carried by the bimetallic .elementfrom the stationary contacts for opening the electric circuit, and a lever pivotally carried by the base and having means thereon for engaging the bimetallic element adjacent its mounting means when the lever is moved to one position to separate the contacts carried by the bimetallic element from the stationary contacts and open the electric circuit.

6. A combined circuit breaker and switch comprising, an insulating base, a pair of stationary contacts carried by the base, a snap acting bimetallic element having a pair of contacts for normally engaging the stationary contacts to complete an electric circuit through the bimetallic element, means between the contacts of the bimetallic element for supporting the bimetallic element on the base, said snap acting bimetallic element operating when the temperature therof increases to a predetermined value to separate the contacts carried by the bimetallic element from the stationary contacts for opening the electric circuit, a cover carried by the base, and a pairof toggle levers, one of the levers being pivotally carried by the cover and extending there-'- through to serve as a handle to be manually manipulated, and the other lever being pivotally carried by the base and having means thereon for engaging the bimetallic element adjacent its mounting means when the toggle levers are moved to one position to separate the contacts carriedrby the bimetallic element from the sta'-Y tionary contacts and open the electric circuit.

'7. A combined circuit breaker and switch comprising, an insulating base, a pair of stationary contacts carried by the base, an elongated snap acting bimetallic element having a contact adjacent each end for normally engaging the stationary contacts to complete an electric circuit aaeenaec v throughy .thebimetalhc element, `said elongated "snapractingfbimetallic[element having a pair: `of

separate thecontacts carried by .the bimeta-llic v elementwfrom the .stationary contacts and :open the electric; circuit.

-;8. .1A combined circuit breaker and. Vswitchcon'iprising; :in-.insulating ibase,` a pair of stationary contactsfcarried bythe base, an elongated snap actingk bimetallic lelement having a contact ladjacent 'each end `for. normally engaging fthe stationary contacts to `complete an `electric circuit through the biinetallic element, `said elongated snap acting birnetallic element having apair'of longitudinal slitsridefining a pair of outer legs andwawcentral Aleg and 'the' `central leg being crowned,means for .mounting the central-leg of the bimetallicielementon the basa-said snapacting bimetallic element Roperating when the teinperature thereof :increases to4 a predetermined value-torseparate the contactscarried by the oimetallic'i-element 4from the 'stationary contacts .forcopeningithe electric circuit, a cover carried .bythe base-,wand `a pair oftoggle levers, one :of

thealeversr-being pivotally carried bythe cover andrextending therethrough* to serve as ar'handle to ibevmanually manipulated, Vand 'the-other lever being ,-pivotally'carried` by the4 base `and having means,thereonforengaging theouter. legs of the bimetallic elementwhen thetogglelevers are moved ritoione position to separate, the contacts carried-by Ythe birnetallic element from the stationarv contacts :and iopen the lelectric circuit.

9. A circuit breaker comprising, ian insulating baseshaving acentral rectangular opening, a pair of #posts -rsecured` to and extending through the baseion'opposite sidesfof the central-opening and eachrhaving a'stationarycontact on its end,.an elongated-snap v,acting birnetallic `element ihaving a contact'adjacent4 each-,end for normally engaging therstationaryv contactsV to .complete an electric i circuit through` the bimetallic element,` ysaid elongated snap acting bimetallic element having apair o'flongitudinalI slits defining a .pair ofouter legs iafnd azcentral leg and `the central legbeing crowned and provided with a central: rectangular opening; a'central'postof rectangular cross section `having a head "and extending through `the central'opening .in th'ebimeta-llic element and adjustablyfsecured in the central opening inthe base-springmeans on the central post between thewbimetallio element and the base for maintainingthe bimetallic element against the head on theI central post; said snap acting bimetallic elementoperating when the temperature thereof increases to a :predetermined value to separate the contacts ecarriedfby the' bimetallic "element from' the stationary contacts 'for opening the elecm tric circuit.

10.- 'A fcombined circuit breaker `and switch comprisingyan insulating beschaving a central rectangular opening,I a pairr of posts securedl to and extending through thebase on opposite sides 'of-'the centrall opening :and each having astav tionary contact on its :endwanielongatedyeinap .acting .fbimetallic elementl having .a Contact r adja- `centzeaclogenrl foranormallyengaging .the stationary -contacts :to-rcomplete. Yannlelectric :circuit through the bimetallic element,` said elongated snap 1 acting `bimetallic element having. a. .'pairfiof longitudinal slitsfdening a pairfof outerlegszand a central leg and .the centralleg 4being:crowned and provided with a central rectangular opening, a centralipost of reotangularlcrossfsectionx-having a head and extending through .thefoentraiff'opening in the birnetallic:elementiandadjustablyxse- 4cured in the central .opening-.inthe.baseaispring :means on thecentral `post between the 4bimetallc element and- .thebaseffor'maintaining thepbimetallic element against; theJ head ,on z the `central post, said snap` acting `bimetallic element zoper'atling when the-temperature thereof fincreasessto a `nredetermined val-ue toseparateithe contacts .carried bylthe :bimetallic elementgfrom the Astationary contacts for :opening 'the .electrica` circuit, a

pair of .recesses :in the base :on oppositesides'fof the central post, Aal U shaped leverextending 'over the birnetallic element and having its ends pivotally .mounted :in thefrecesses, and Ameans `onthe leverior engaging theouter legs ofrthetbimetallic element when the lever .is moved'toloneposition to'separate the oontactscarried bythelbimetallic element `from the `stationary contacts .l and zopen the lelectric circuit.

1l. A `combined `circuitbreaker iandwswitch comprising, an insulating .base having acentral rectangular opening, a Vpair ofzposts vsecuredzto .and extending through the base onaopposite'sides of the central `opening andeach 4l'iavingaYstationary contact on its end; an ='elongated.;snap

`acting .himetallic element havingxa :contactU ad- `iacent each end for normally engagingthenstationary contactsto 'complete annelectric circuit through vthe.'bimetallic element; saidfelongated snap acting bimetallicel'ement having a :pair lof Ylongitudinal slits .defining a pair Vof outer legs and a 'central leg and `the 4.central-:leg` being crowned and providedwith i a centralrectangular opening, a 4central post of ^rectangularicrossasec- `tion lzaving a `head 'and 1 extending throu'ghlthe central openingin the ibimetallicrelementiand adjustably `secured in the central openingcin :the base, spring `means ont-he central post lbetvsreeu thebimetallicel ementand the base f'ormaintainingizthe `bimetallic element :against theuhe'a-:son the central post, i said acting Abirrretallic element -operating when the temperaturethereof increases -to a `predetermined'.value to separate the contacts carried ibythe bimetallic element from the stationary contacts `fortopening"theaelectric circuit, a pair of recesses 'in :thebase ron oppositesides of the centralr post, Aa 'Ueshaped lever extending :over :the birnetallic :element .and having endspivotally 'mounted` infthe recesses, and means ontheilever forengaging theiouter legs of the bimetallic element whenathe-"leverpis moved to `one position to separate theicontacts carried by the bimetallic `element from the stationary contacts and open theelectricfrcircuit a cover carried by the basefsaid U-shaped `lever formingone of a pair of toggle'levers, theiother toggle lever being pivotallycarried byfthe Icover and extending therethrough with its .outer end serving a handle to be manuallyamanipulateo' and with its inner end provided with` a 4spring pressed plunger engaging the U-shaped' lever.

.12.-A combined circuit breaker` .and switch comprising,l an insulating base, a 7pairdof Astationary contactscarried by the base, asnap. acting bimetallic element having a pair of contacts for normally engaging the stationary contacts to complete an electric circuit through the bimetallic element, means between the contacts of tne bimetallic element for supporting the bimetallic element on the base, said snap acting bimetallic element operating when the temperature thereof increases to a predetermined value to separate the contacts carried by the bimetallic element from the stationary contacts for opening the electric circuit, a pair of recesses in the base on opposite sides of the mounting means for the bimetallic element, a Ushaped lever extending over the bimetallic element and having its ends pivotally mounted in the recesses, and means on the lever for engaging the bimetallic element adjacent its mounting means when the lever is moved to one position to separate the contacts carried by the bimetallic element from the sta-- tionary contacts and open the circuit.

13. A combined circuit breaker and switch comprising, an insulating base, a pair of stationary contacts carried by the base, a snap acting bimetallic element having a pair of contacts for normally engaging the stationary contacts to complete an electric circuit through the bimetallic element, means between the contacts of the bmetallic element for supporting the bimetallic element on the base, said snap acting bimetallic element operating when the temperature thereof increases to a predetermined value to separate the contacts carried by the bimetallic element from the stationary contacts for opening the electric circuit, a pair of recesses in the base on opposite sides of the mounting means for the bimetallic element, a U-shaped lever extending over the bimetallic element and having its ends pivotally mounted in the recesses, and means on the lever for engaging the bimetallic element adjacent its mounting means when the lever is 4 moved to one position to separate the contacts carried by the bimetallic element from the stationary contacts and open the circuit, a cover carried by the base, said U-shaped lever forming one of a pair of toggle levers, the other toggle lever being pivotally carried by the cover and extending therethrough with its outer end serving as a handle to be manually manipulated and with its inner end provided with a spring pressed plunger engaging the U-shaped lever.

14. A combined circuit breaker and switch comprising, an insulating base, a stationary contact carried by the base, a snap acting bimetallic element supported by the base and carrying a contact for normally engaging the stationary ccntact to complete an electric circuit through the bimetallic element, said snap acting bimetallic element operating when the temperature thereof increases tc a predetermined value to separate the contacts for opening the electric circuit and operating when the temperature thereof decreases to a predetermined value to engage the contacts for opening the electric circuit, a cover carried by the base, and spring biased lever means carried by the base and extending through the cover and movable between two positions and maintained at either of said two positions and having means thereon free from the birnetallic element when the lever means is in one position to permit free operation of the bimetallic element but engaging the bimetallic element when the lever means is in the other position to separate the contacts and open the electric circult.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 2,249,837 Lee July 22, 1941 2,462,244 Wise Feb. 22, 1949 2,520,873 Bean Aug. 29, 1950 2,520,874 Bean Aug. 29, 1950