US1022545A - Electric oven. - Google Patents

Description

J. G. vGRONBERG Iz/W. D. HUDSON. ELECTRIC OVEN.

PPLIGATION FILED 11:13.15, 1909.

1 ,022,545. Patented Apr. 9, 1912.

J. G. GRONBERG &'W. D.' HUDSON. BLEGTRIG OVEN. APPLIGATION FILED 213.15, 1909.

1,022,545. Patented Apr.9,1912.

5 SHEETS-SHEET 2.

J. G. GRONBERG & W. D. HUDSON. ELECTRIC OVEN. APYLIOATIUN vFILED PEB.15, 1909.

Patented Apr. 9, 1912. 5 SHEETS-SEEET 3.

J. G. GRONBERG 61: W. D. HODSON.

ELECTRIC OVEN. APPLICATION FILED P21345, 1909.

5 SHEETS-SHEET 4.

fe//zW-, f Jg W Patented Apr. 9, 1912.

JfG. GRONBERG n W. D. HODSON.

ELECTRIC OVEN.

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Patented Apr. 9, 1912.

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UNITED sTATEs PATENT oEEicE.

JANESVILLE, WISCONSIN, ASSIGN ORS TO THE CALOBIC COMPANY, F JANESVILLE, ATISCONSIN, A CORPORATION OF WISCONSIN.

ELECTRIC OVEN.

Specification of Letters Patent.

Patented A pr. 9, 1912.

Application led February 15, 1909. Serial No. 478,012.

To all whom 'it may concern:

Be it known that we, JOHN G. GRONBERG and WALTER D. HoDsoN, citizens of the llnited States, residing at Grand Rapids, in the county of Kent and State of Michigan, and Janesville, in the county of Rock and State ofl VVisconsi'n, respectively, Ahave invented a certain new and useful Improvement in Electric Ovens, of which the following is a specification.

Our invention relates to electric ovens.

It is illustrated in the accompanying drawings, wherein- Figure l is a vertical section through an oven arranged to receive our heating device: Fig. Q is a similar view at right angles to Fig. l; Fig. 3 is a plan View of the controlling switch; Fig. 4 is a section of the controlling switch showing a cut-Out magnet; Fig. 5 is a plan view of the lower section of the heater plate, with parts removed; Fig. 6 is a cross section therethrough; Fig. 7 is a plan view of the heater plate, and Fig. 8 is a diagrammatic view showing the circuits.

Like parts are indicated by thel same letter in all the figures.

A A are the frame portions of a box or receptacle having the bottom A1, the top A2. the door A, the glass panels A4, the interior compartment wallA5, the insulation packing A and the supporting legs A7. Inside the interior com artment and forming the bottom thereof 1s the depressed pan l provided preferably with a central depression B1 in which lies the terminal plate B2 which is secured in position by the bolts Bf' and is provided with the rings B4, B5 and the central pin B, whence lead respectively the conductors B7, B8 and B9 to the switch terminals. This switch is shown as contained in the box C and consists of the table C1, the terminals C2, C3, whence lead the heater conductors B2 and B7 respectively, the switch arms C4, C5 which make contact with the terminals C and C7,

whence lead the line wires C8 and Ctrespectiv'ely. The two switch armsare connected by the cross ypiece C70 and have the controlling knob C11. They are associated with a spring C12 which 'tends to force them out so as to break the contact. Mounted on the switch is a cut-olf magnet D having one end D1 of the pivoted armature exposed to it. The other end of this armature is provided with a block D2 opposed to a detent D3 which is pivoted at D* and is adapted to engage a projection D5 associated with the switch arms. These parts are secured in any desired position as indicated in Fig. l where the switch arms are shown as thrown back by thespring C12. The conductor adapted to aid in controlling the' cut-out magnet is indicated by the letter B9 and it leads from the central terminal B6 to the magnet D. The heating plate consists of the body E which is preferably of 'soapstone, and the top E1 likewise preferably of soapstone. In the body E are the conductor rings E2, E3 and E4. The conductor ring E2 is adapted, when the plate is in position, as indicated in Fig. 2, to make contact with the contact ring B,

while the conductor ring E3 makes contact 'Y with the contact ring B5, and the central terminal B makes contact with the headof a screw E5 which bears against the contact ring E4. When the plate body E is placed within the receptacle as indicated in Fig. 2, these several rings which it carries are thus in electrical connection with the severalv conductors above referred to.

On the top of the body E is formed a circular groove F. There are three sections to. this top of the body portion and we shall describe one of them. In one section of this groove is placed the terminal F1 in opposition to the terminal F2 which latter is in Contact with the outer coil of the resistance F3 which usually takes the shape of a ribbon wound with insulation between its several coils. Fromv this same terminal F1 projects a two part curved thermostat spring F5 which carries at its outer end a contact point F5. This point is in opposition to a contact point F6 associated with 'an inleading conductor F7 which makes contact with the contact ring E4 from which contact ring leads the conductor B9. Opposed to the terminal F1 is the terminal Fs whence leads a conductor F9 to the outer contact ring E2 in the bottom of the heat- 5' and 6,- we can trace these circuits. G is A a plug which, when inserted, closes the conf dicated.as C8 and C9.

nection between the otherwise separated terminals F1 and F 8. Whenthis is done a circuit is created as follows, beginning at the line wires back of the switch which are in- Assuming that the current is flowing through C9 in the direction indicated by the arrow, if the switch be closed it will pass through the switch arm to the terminal C2, thence along conductor BS to the inner ring E3, thence along the short conductor Gr2 to the inner end of the resistance coil through the resistance coil to the terminal F2, through block G to terminal F8 through conductor F to the outer ring E2, thence by the conductor B7 to the other arm of the switch, thence out onto thel line wire C8. Thus a circuit is established through the resistance and heat begins to be generated. 'As soon as sufficient heat has been generated to inwardly bend the resistL ance spring Ftanother circuit is established as follows: through'conductor C9, through the switch arm terminal C2, through the cutout magnet D, along conductor Bg to the central contact ring E4, thence along conductor F7 to the contacts F6 and F5 which are brought int-o connection by the forward flexing of the spring F, thence alongv F* to the terminal F1, plug G, terminal F 8, conductor F", outer rin E2, conductor B7, and out in the other main line. This energizes the magnet D, causing it to bring down its armature in the structure shown in Fig. 1 o r in the struct-ure shown diagrammatically in Fig. 8, whereupon the switch arm is revleased and the spring C12 forces it out as shown in Fig. l, thus breaking both circuits.

G1 G1 are stop screws to vary the tension on the springs F t and thus vary the time within which, at a given heat, they will be sutliciently flexed to close their respective circuits.` The. arrangement of these stop screws and thermostat springs is such as to give three differing results. If a temperature of a certain height will flex the first of these springs, the set screws are so adjusted on the others that one hundred degrees more of heat is required before the second one is flexed, and a still higher degree before the third is flexed, or, if the parts are properly adjusted, they may be so arranged that it will take a certain amount of time at a given temperature to flex yeach spring and they will vary among themselves as to time. The Objectis to have a variation between these several thermostatic invention. We shall set forth in the claims what appears to be essential.

`The top ofthe heating plate J is preferably inthe shape of an inverted dish, cut out at J? and it is perforated at J2. Its lower rim J3 is slotted as at J to admit air under the rim into the interior of the dish above the heating coil and to permit such air when heated to pass out the holes.

Mounted on the top of the heating plate `is the-cover K preferably corrugated as indicated at K1 and provided with a ring K2 which overhangs the top of the heating plate. It is secured in position by the bolts and nuts K3 K3. These radial corrugations leave inwardly open grooves Kx K* wherebyT the air escapes from under the cover and around its edges at the centralopening K1. For convenience we have connected the inner end of the coil with la ring L to which the conductor leads and we have surrounded the coil with a ring M to which the conductor leads.

The use and operation of our invention is as follows: An oven of the type shown in Fig. 2 having been provided, the switch is in position on the side and the three conductors are brought down inside and secured to the three terminals or contacts in the tei'- minal plate in' the bottom of the receptacle. The heating plate, having its several parts properly arranged and associated together as indicated, for example, in Fig. 6, is then placed in position in the bottom of the receptacle on top of the terminal plate, its two terminal rings and terminal center piece being placed in position so as to make electrical contact with the three contact rings on the bottom ot the plate body. This leaves the parts in the position where the heating plate is resting on the terminal plate in the bottom of the receptacle indicated in Fig. 1. The switch is open as indicated in Fig. 1. The plug G is inserted between the predetermined pair of coil and cut-out terminals. The operator will select that pair which will bring into play the particular thermostatic spring which he desires to have acted upon. The objects or materials to be subjectedvto the heat are then placed in position on the cover of the heating plate and the switch is closed. Thereupon the current, as previously described throuv h the switch or lnleading wires C and C", 1s supplied which traverses the heating coil until the plate has been raised to a certain temperature or kept at a certain temperature for a certain predetermined time. Thereupon the thermostaticspring F, associated with the plug G, is moved forward until the points F5 and F 5 contact, whereupon a circuit is made through the cut-out magnet D. This magnet throws down its armature, releases the handle and permits the spring C12 to open the switch and the current is cut off from both the mag: net and heating coil. It will be understood that these heating plates could be 'arranged in any desired manner or that there might be a series of them in the receptacle, 'for eX- ample, one at the top and one at the bottom. It will also be understood that these receptacles and plates while shown as circular in outline, may be ofany desired shape. Any species of switch can be used. Soapstone is the preferred material though other substances might be employed.

Broadly speaking, our invention embraces a switch, a cut-out, a heating coil, circuit closers whereby )a current' can be made to traverse the heating coil, a .thermostatic circuit closer whereby a currentmay be made to traverse the cut-out responsive to variations in heat of the heating coil, and means whereby the cut-out can shut ofthe current from the heating coil.

The dish shaped bottom of the oven is intended to receive and drain away from the eenterthe grease or other liquid whichmay tend to collect in the bottom of the oven. The series of thermostatic devices, and there may of course be any number of them, are to be adjusted and adapted sothat when a sufficient degree of heat has been obtained or when the ,heat is continued for a suilicient length of time, the supply of current will be automatically cuthotl" after which, of n course, the heat remains without further '1ncrease and practically at. a uniform stage for an indefinite period. One advantage of this arrangement is that no attention is required# as the user may, upon applying the current by throwing the switch, the oven being closed and the cooking utensils in position, go away and leave the apparatus, knowing that there is no danger of overheating, and even assured that the requisite amount of heat will be obtained and that the device will then automatically cut itself out of further current supply.

Our invention can be used for enameling ovens, hot water heatin systems, and other purposes as well as for eless cook stoves.

We claim:

1. In a heater, the combination of a heating plate comprising abody and a top.with intermediate space with a heating coil associated therewith, anelectric supply circuit connected with the heating coil, a circuit breaker therefor, an electric circuit for said circuit breaker, additional means for closing the supply circuit and means yresponsive to the temperature for operating the circuit breaker to stop the heating process when any predetermined temperature has once been reached. v

2. In a heater, the combination of a heating plate comprising a body and a top, with an air circulating space between them, a heating coil associated therewith, an electric supply circuit connected with the heatin\g coil, a circuit breaker therefor, additional means for closing the supply circuit, and means responsive to the temperature for operating the circuit breaker to stop the heating process when once any predetermined temperature has been reached.

3. In a heater, the combination of a heating plate comprising a body and a top having discharge openings therethrough with an air space between them, and side inleading openings, a heating coil associated therewith, an electric lsupply circuit connected with the heating coil, a circuit breaker therefor, additional means for lclosing the supply circuit, and means responsive to the temperature for operating the circuit breaker to stop the heating process when any predetermined temperature has once been reached.

4. In a heater, t-he combination of a heating plate comprising a body, a top and cover, with air circulating spaces between them, a heating coil associated therewith, an 'electric supply circuit connected with the heating coil, a circuit breaker therefor, additional means for' closing the supply circuit, and means responsive to the temperature for operating the circuit breaker to stop the heating process when any 'predetermined 'temperature has once been reached.

5. In a heater, the combination of a heating plate comprising a body and a top, with a space .between them and a corrugated cover on the top, with a space between it and the top, a heating coil associated therewith, an electric supply circuit connected with the heating coil, a circuit breaker therefor, additional means for closing the supply circuit, and means for operating the circuit breaker responsive to variations' in heat.

6. In a heater, the combination of a heating plate comprising a body, a top and a cover having opening therethrough, an air space between the top and cover and' the `body and top, said space having outside openings, a heating coil, associated therewith, any electric supply circuit connected with the heating coil, a circuit breaker therefor, additional means for closing the supply circuit and means for operating the circuit breaker responsive to variations in the temperature.

7. In a heater, the combination of a receptacle with a terminal plate in the bottom thereof, a heating plate resting on such terminal and in electrical contact therewith,` a heating coil associated therewith, an electric supply circuit connected with the heating coil, a circuit breaker therefor, and means responsive to the temperature for operating the circuit breaker to stop the heating process lwhen any predetermined temperature has once been reached. y

8.'In a heater, the combination of a heating plate with a heating coil associated therewith, an electric supply circuit connected with the heating coil, a circuit breaker therefor, additional means for closing the supply circuit, and means responsive to the temperature for operating the circuit breaker to stop the heating process when any predetermined temperature has once been reached, a terminal plate on which the heating plate rests, and with which it is in electrical contact, and conductors leading from the outside to the terminal plate and forming part of the electric supply current.

9. Ina heater, the combination of a heating plate with a heating coil associated therewith, an electric supply circuit connected with the heating coil, a circuit breaker therefor, additional means for closing the supply circuit, means responsive to the temperature for operating the circuit breaker to stop the heating process when any predetermined temperature has once been reached, an inclosing receptacle, a terminal plate in the bottom of the same on which the heating plate rests and which is in electrical contact therewith, and conductors from the terminal plate to the circuit breaker operating devices.

10. In a heater the combination with a heating plate of heating means therewith, comprising a pair of terminal rings one within theother a coil surrounding said rings and terminating at either end in one of them, av switch, and a conductor connecting said switch andA said rings and means connecting` said switch with any suitable source of power. 1

11. In a heater the combination with a heating plate of heating means therewith,

A comprising apair of terminal rings one `within the other, a coil surrounding said rings and terminating at either-end in oneo them, a switch and a conductor connecting saidswitch and said rings and a connection between said switch and any suit-able source of power, and electric magnetically controlled operating means for saidswitch.

12. In a heater' the combination with a heating plate of heating-means therewith,

p 1,022,545 l l comprising a pair of terminal rings one within the other, a coil surrounding said rin s and terminating at either end in one of t em, a switch and a conductor connecting said switch and said rings and a connection between said switch and any suitable source of power, and electromagnetically controlled operating means for said switch, a terminal concentric with said rings and a circuit from one of the terminals of said switch through said magnetic means to said terminal, thermostats disposed about said coil and communications from said center terminal to one of the terminals of said thermostat a removable connection between the other terminalof said thermostat and the outer terminal ring.

13. In a heater, the combinationl of a heating plate with a heating coil associated therewith, an4 electric supply circuit connected with the two ends of the heating coil, a circuit breaker therefor, means including an electric circuit for operating the circuit breaker, and means consisting of a removable plug for simultaneously closing the two circuits.

14. In a heater, the combination of a heating plate with a heating coil associated therewith, an electric supply circuit connected with vthe two ends of the heating coil, a circuit breaker therefor, means including anvelectric circuit for operating the circuit breaker, and a thermostatic circuit closer in such circuit, and means consisting of a removable plug for simultaneously c osing the two circuits. 1

15. In a heater, the combination of a heating late with a heating coil associated therewit an electric supply circuit connected with the two ends of the heating coil, circuit breaker therefor, means including anelectric circuit for operating the circuit breaker, and a thermost-atic circuit closing device in proximity to the heating plate and responsive to variations in heat, and means consisting of a removable plug for simultaneously closing the two circuits.

16. In a heater, the combination of a heating plate with a heatingcoil associated therewith and laid thereon, an outer conducting riiig within the coil, an inner conducting ring within the coil, a supply circuit connected at its terminals with the inner and outer rings respectively, a switch in the supply circuit, and a series of means for throwing the switch unequally, responsive to variations inthe heat of the plate.

17. In an electric oven, the combination of a receptacle with a central terminal block therein, a heating plate supported thereon, and mutually contacting rings on plate and block whereby the electric circuits are estab- Y of a receptacle with a central terminal block thereof, a heating plate 'resting upon the 10 therein, a heating plate supported thereon support, and an outwardly inclined collectund mutually contacting rings on plate and ing dish-in the bottom of such oven.

block whereby theelectric circuits are estab- JOHN G GRONBERG lished when the plate is put in position on the block, and a supply current with a switch WALTER D' HODSON' on the outside of the oven. Witnesses:

19. In an electric heater, the combination H. K. DEAN,

of an oven with a support in the bottom A. T. THoR'rs.

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