US1683196A

US1683196A - Electric heating system

Info

Publication number: US1683196A
Application number: US233968A
Authority: US
Inventors: Leslie A Kempton
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1927-11-17
Filing date: 1927-11-17
Publication date: 1928-09-04
Anticipated expiration: 1945-09-04

Description

Sept. 4, 1928. 1,683,196

L. A. KEMPTON ELECTRIC HEATING ,SYSTEM Filed NOV. 17, 1927 lnve-tor`: Leslie A. Kemp-ton,

Patented Sept. 4, 1928.

UNITED STATES 1,683,196 PATENT oFFicE.

LESLIE' A. KEMPTCN', 0E BRIDGEPORT, CONNECTICUT, AssTGNoR To GENERAL ELEC- TRIC COMPANY, A CORPORATION or NEwYoRK.

ELECTRIC HEATING SYSTEM.

Appiicafion. inea November i7, i927. seriai No. 233,968.

l My invention relates to electric heating systems, inoie particularly to three-wire electric heating systems, and ha's for its object the provision of simple and reliable means for making the electrical connections for various rate'sof heat generation.

My invention relates more especially ,to

electric heating systems in which a three-Y wire supply source is used havingtwice the voltage between the two outside wires as between each outside wire and the middle or .neutral wire, for example, 22() volts between the two outside wires and 110 volts between each outside wire and the neutral. In the operation of electrical apparatus on a three-wire circuit of this character, it is desirable to connect the load across the. two4 outside wires as far as possible so as to balance the load on the circuit. In apparatus iii which a plurality of heats are provided, i. e., a pluralityv of diiierent rates of heat generation, lthe connections may be arranged so that the .heating lresistor is connected across the' two outside wires to give the high heat, whereas the lower heat' or heats may beA obtained by connecting the resistor to one side only of thev supply source. Inma-king the connections for three heats, for example, i. e., high, nicdium and low heats, the heating resistor may be divided into sections whereby one or both of the sections may -be"uti1ized. For high heat the two sections may'lbe connected in series across the two outside wires, for medium heat one .section maybe connected l across one outside wire and neutral, and

for low heat the two sections may be connected in series across one outside wire and neutral.

In accordance with my invention I provide simple and reliable means for carrying out the aforesaid connections for the three heats comprising two suitable rotatable contact members which are operated together and arranged to cooperate with suitable. stationary contacts. The stationary contacts are electrically connected to the heating resistor and to the three electrical supply wires.

For a more complete-understanding vof my invention reference should be had to the acompanying drawing in which Fig. 1 is a sectional view of means for carrying out the various connectionsln accordance with my invention; Fig. 2 is a :Era mentary plan view -of the device shownin. ig. 1; Fig. 3 is a sectional v iew taken along the line of Fig. 1 looking in the direction of the arrows;

Fig. 4 is a fragmentary perspective view such as a phenolic) condensation product.

This Abase is circular in iorm and has a tu-.

bular metallic member 11 embedded in it and' extending centrally through it, this member forming a bearing for an operating shaft 12 carrying two

electrical contact members

13 and 14 which are rotatably mounted on the shaft in electrically insulating relation with respect to the shaft and with respect to each other. As shown, the

rotatable contacts

13 and 14 are 4mounted on polygonal electrically insulating blocks 15 and 16, the contact members being provided with polygonal 'apertures which tit on the blocks.l in turn secured to a poylgonal metallic hub 17 provided with a central bore in which the shaft 12 is free to turn. vBarrier discs 18 made of insulating material are provided on each side and between the

contact members

13 and 14.

A suitable driving connection is providedv between the shaft 12 and the hub 17 whereby the hub is turned with a snap action from one position to another. As shown a metal plate 11a is embedded in the base 10 and further secured to the base by riveting the journal member 11 oin -to it. This plate 11a is provided with four'projections 19 which are equally spaced around the axis of the shaft 12 and act as stops to define four positions of the

members

13 and 14. A specially shaped pawl 20 is provided having a portion which fits between a pair ofprojections 19 and providedl also with a bore in which fits-an eccentric cam member 21 secured to .the shaft 12. This pawl 2O has a projection 22 at its end which ts in a radial slot in The blocks are 2, nasales member 23 which t in slots in a metallic with-the variousfstationary contacts. 'The memberv 241Y provided with an octagonal bore stationary contacts may also be considered as itti'ng on the hub. A spiral spring 25 is being arranged in two groups with which the also provided surrounding shaft 12 and

havmembers

13 and 14 cooperate respectively,l ing its ends bent laterally so as to terminate' member 13 cooperating with av groupcom- 70 intwo

parallel portions

26 and 27. These prising the three

stationary contacts

30, 32b portions embrace two

vprojections

28 and 29 and 33b and member l14 cooperating with a hich are secured to the shaft'12 and the Vgroup comprising the four, stationary conhub 17 respectivel i tacts 30, 31, 323L and 33a. y

AS thus arranged, it will be observed that Referring to Figs. 5 -8 inclusive, the. elec- 75 when the shaft 12'is turned by knob 12'JL in tric heating resistor,'which, for example, either direction, the spring is compressed by may be a hot `plate or oven heating unit of.,

' the engagement of the projection 28 with it an electric range, is provided with an interand a force thereby applied to the hub mediate connection pointJ or tap 35 wherebyA through the agency of the projection 27. At it is divided into sections 36- and 37. As 80 the same time the pawl 2O is withdrawn from shown the tap 35 is in the center so that the between the projections 19. by the turning l'

sections

36 and 37 have equal resistance's,

of' the cam 21, and when the shaft 12 has -although obviously the 'tap may be `at some been turned approximately '90 the pawl will other point whereby the sections are of .r

. be withdrawn sufficiently to clear theprojecunequal resistances, if desired. The central 35 tion 19 against which it is pressed by the point 35 is electrically connected toy the'con-4 spring, and it will then snap into the space tact 31, one of the outside terminals, as between the next two projections' 19. In' shown theoutside terminaljofsec'tion 36,'.is

' this manner Ithe contact

members

13 and 14 connected to the'contact32", while-the other v fare snapped from one position to another. outside terminal isconnected to the station-` 9 l The contact member 13 is provided with a tary contacts 33EL and 331. The neutral .wire

relatively long radial contacting projection of the three-wire supply source 38, shown or arm 13a (Fig. 5), a relatively short proas the middle wire, is co ectedV to the stajection 13h situated diametrically opposite tionary contact 32a, while the two outside 3 the projection 13', and with a shorter radial wires are connected respectivelyto the sta- 9E contact projection 13 at right angles thereto. tionary contacts 30a and 30". n The contact member 14 is rovided with a With the connections previously described,

. single relatively long radialJ contact projec- Awhen the switch is. turned to the position .tion 14a and witli two shorter projections shown in Fig. 5, i. e., the

members

13 and 14 3 5 14,7 'and '14 at right angles to projection 14EL turned to the positions indicated, the heating 1( l and diametrically opposite each other. The resistor is disconnected from the supply:

' vvtwo

members

13 and 14 are secured to the source,this position being the oil posit-ion;v

'hub 17 so as to rotate in parallelplanes but- For high heat, i. e. highest rate of heat gen-I with' ai 90"4 displacement, 1. e., with the coneration, the switch is turned to the 'next 40" tact projection 13 extendin'g at right angles position in a clockwise direction which Ais 1 with the projection 148%, as shown in Fig. 5. shown in Fig. 6, whereby it will be observed Sets of

stationary contacts

30, 31, 32, and that the two ends of the resistor are con- 33 (Fig. 2) are secured to the base member nected throughIl the two. switch members 13 in (position to be engaged by the members 13 and=14, respectively,"to the outside wires of t an 14 in their. four positions, these stationthe supply source. This connects the twol `1A ary contacts being eglually spaced at 90 sections of the resistor in series across thet angles on the base T e set 30 comprises an higher voltage wires of the supply source, l

upper'short contact 30 and alower long conno connection with the central tap 35 being l tact 30",*-the set31 comprises a single short provided. For medium heatthe switchis upper contact, while the /set 32 comprises an turned in a clockwise direction to the next 1 -upper long contact 32a` and a lower long' position, as indicated inF ig. @whereby the \c0ntact 32. 4 The set 33 comprises an upper central tap 35 is connected through. the -long contact 33a and a lower short contact switch member 14 to the neutral wire, and 33"; It will be understood that the 'lower the outside terminal of the section 37 is 4constationary contacts are engaged by lthe .rotatnected through the switch member 13'to one 1 able contact 'member 13, whilethe upper of the outsi e wires of the supplysource.

' stationary contacts are engaged -by Vthe con- This connects the section 37.l acrossone side tact member 14 the short stationar contacts of the supply source, thesection 36 being being engaged y the long rota-tab e'contact deenergized. For low -he'at the s'witch is 0.1 projections, and vice versa. In the sets 30 turned in a clockwise'direction to its next l and 32 e contacts are electrically insulated position in whichi one end of the resistor is from ea other,but the two contacts of the. connected through the member 13 to set 33 are .electrically connected together. oneoutside wire and the other endof the Suitable binding screws 34 are frovided resistor is connected through the g switch u whiereby electrical connections maylbe made member 14 to the neutral wire. This donneel tion puts the twov sections in seriesl across one side of the supply source. l

It should `be noted that the rotating contact member 13 serves the purpose of connecting one end of the resistor to one of the outside wires .in all three of the operating positions. rThe same end of the resistor is connected in thehigh and low heat connections, while for the medium heat connection the opposite end of the resistor 'is connected. The, rotary contact member 14; serves the purpose of making the connections for the remaining outside wire and the neutral wlre. For-high .heat it-will be observed that thls contact member connects one end` of the resistor to one outside wire, for medium heat it connects the central point to the neutral wire, and for low heat it connects one end of the resistor to the neutral wire.

In the. modified form of my invention shown in Fig. 9, the electrical connection between t-he Contact 33b and the contact 33a is eliminated and in place thereof a connection is provided between the contact 33b and the contact 32h.- Vith this arrangement'the connections for the resistor are the same as previously.I described in 'connection with F igs..5 to 8 inclusive, with the exception that on the medium heat connection shown lin Fig. 7 the reverse end of the resistor as compared with- Fig. 7 is connected to one outside wire. This energizes section 36 of the resistor instead of section 37, as shown in Fig.' 7. This will be understood with reference to Fig. 7'. In Vother words, with the` connections shown in Fig. 9 the switch blade 13 connects the same endof the resistor to the same outside wire for all three heats, this end ofl the resistor being that end whichis shown connected by the switch blade 13 in Figs. 6 and` 8.

While I have described my invention as embodied in concrete form and as operating in a specific manner in accordance with the provisions of the patent statutes, it'

should be understoodl that I do not limit my invention thereto since Various modifications thereof will i suggest themselves to those skilled in the art without departing from the spirit of my invent-ion, the scope of which is set forth in the annexed claims.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. The combination with a heating resistor provided with an intermediate connection point, of a supply source provided with two outside wires and a neutral wire, a switching member for connecting one end of said resistor to one of said outside wires in any one of three positions, and a seco-nd switching member for controlling the connections from said intermediate point and one end of said resistor to said neutral wire and one of said outside' wires in three positions so asto give three different rates of heat generation.

2. The combination with a heating resistor provided with an intermediate connection point, of a supp source prov1ded wlth two outside wires an a neutral wire, a switching member for connecting one end of said resistor to one of said outside wires in any one of three positions, a second switching 'member for cont-rolling the connections from the other .end of said resistor and saidi'ntermediate point to the other outside wire and said neutral -wire iri said three positions so as to givethree different rates of heat generation,

.and means for operating said switching members simultaneously.

3. The combination with a heating resistor provided with an intermediate connection point, of a supply source' provided with two outside wires' and a neutral wire, a rotary switching member for connecting one end of said resistor to one of said outside wires in any oneof three positions, a second switching member for controlling the connections from said intermediatepointand o-ne end of said resistor to said neutral wire and one of said outside wires in said three positions so as to give three different rates of heat gen' eration, and means for operating said switching member simultaneously from one position to another.

,4. The combination with a heating resistor provided with an intermediate connection. point, of a supply source provided with two .outside wires' and a neutral wire, two rotary l,outside wires and a neutral wire, switching means for controlling the connections of said reslstor to such supplysource comprising -a group of three stationary contacts connected respectively to thev two ends of said resistor 1 and one of said outside wires, a rotary contact member cooperating with said stationary contacts in any one of three positions so as to 'connectone end of said resistor to said. outside wire, a second group of four stationary contacts connected, respectively, to said intermediate point, one end. of said resistor,. said neutral wire, and the remaining outside wire, a second rotary contact member arranged to cooperate with said second group of stationary cont-acts in any one of three positions so as to connect one end of 'said resistor to one outside wire for high heat, said intermediate point to said neutral wire for medium heat, and one end of, said resistor to said neutral point for low heat, and means for operating said rotary contact members simultaneously.

6. "The combinationV with a heating resistor provided with an intermediate connectiony point, of a` three wire source of power supswitching means for controlling the conv ber'seach provided with three contacts having anv angular arrangement corresponding -to the angular spacing of said stationary contacts, electrical connections between the ends' of said resistor-and two contactsl in saidglirst group respectively, an electrical connection between the third contact of said first group and an, outside wire of said supply source, electrical' connections respectively between .twov of the stationary contacts 1n said second group and said intermediate point and the neutral w'ire of said supply source,A an electrical connection between one end of said resistor and another stationary contactv in said second group, and an electrical connection between the fourth contact in saidsecond group and the remaining out-v side supply wire, and means'for operating said rotary contact members simultaneously to various positions to give various heats, whereby for high .heat thel ends of said resistor are connected to the outside wires of saidrsupplyV source by said rotany contacts, respectively, for medium heat one end of said resistor is connected to one outside wire by said first rotary contact and said interme-l diate point is connected to the neutral wire by saidsecond rotary contact, and for low heat one end of said resistor is connected to one of said outside wires by saidfirst rotary Contact and the other endof said resistor is connected to said neutral wire by said second rotary contact- In witness whereof, I have hereunto set my hand-this 12th day of November, 1927.

LESLIE A. KEMPTON.