US1804130A - Electric range - Google Patents

Description

May 5, 1931. c. D. STARR 1,804,130

ELECTRIC RANGE Filed Nov. 14. lsza N .Nrr) A w 67 Il ff 7 @isl A6 27 AAA Ann Patented May 5, 1931 i UNITED STATES PATENT OFFICE OLARENCED. STARR, 0F BARRDGTON, RHODE ISLAND, ASSIGNOR T0 BARSTOW STOVE GOIPANY, 0l' PROVIDENCE, RHODE ISLAND, A CORPORATION 0F RHODE ISLAND ELECTRIC RANGE Application led November 14, 1928. Serial No. 819,859.'

My invention relates to electric heating apparatus, and particularly but not exclusively to electric ranges and other electrical devices for heating cooking vessels.

The invention, which has among its ob- -jects the control of the electric heater by laccompanying `drawing showing one example of the invention, while the scope of the invention will be more particularly pointed out in the appended claims.

. In the drawing Fig. 1 .shows an elevation, with parts in cross-section, of a fragment of an electric range with a cooking vessel in operative relation to the heater;

Fig. 2 is a somewhat diagrammatic section on the line 2-2 of Fig..1; and

Figs. 3, 4, 5 and 6 are schematic wiring diagrams showing the main controlling switch in diierent operative positions.

Referrin to the drawing, the range illustrated is o the common construction which comprises a frame having a top 1, the latter supporting anfelectric resistance heating element 3, said element, as will be understood by those skilled in the art, commonly comprising a disk or the like of heat refractory material carrying wire coil resistors in grooves on its upper face. The particular form of the electric resistance heating element does not form part of the present invention, and therefore will be described with only such particularity as is necessary to explain how it coacts with the present invention.

Referring particularly to Figs. 3, 4, 5 and 6, the electric heating element, as herein indicated, comprises the resistors 5 and 7 which may be of different heat generating capacity, the resistor 5, for example, being of small heat generating capacity and the `resistor 7 of large heat generating capacity. As indicated in Fig. 1, at the front of the` range is positioned a controlling switch 9 having a rotary operating knob 11. As shown (Figs. 3 to 6) the switch 9 is of the 3 point type having the three operating c ontacts 13, 14 and 15. One side 17 of the line, say a house lightingv circuit, is connected to the switch contact 15, while the other side 19 of this line is connected by a lead 21 to the common mid-terminal 23 of the resistors 5` and 7. The other terminal 25 of the resistor 7 is connected by a lead 26 to the switch contact 13, and the other terminal 27 of the resistor 5 is connected by a lead 28 to the switch contact 14.y The switch 9, which may be of the snap type, comprises, as schematically indicated in Figs. 3 to 6, the contact plate 29 which may be rotated by the knob 11 about an axis 31 into the different positions shown by these figures. Fig. 3'is the olf position in which no current iiows through the resistors 5 and 7.. In the position of parts shown by Fig. 4 current iiows through the low capacity resistor 5 to generate the smallest temperature of which the heater is capable. In

the position of parts shown by Fig. 5 the resistors 5 and 7 are connected in parallel across the line, and in this position of parts the heater illustrated generates the highest temperature oit' which it is capable. In thel position of parts shown by Figs. 6 only the high capacity resistor 7 is connected into the line, and in this position of parts the heater generates a temperature between the low temperature generated when the parts are in the position shown by Fig. 4 and the high temperature generated when the parts are in the position shown by Fig. 5.

As herein indicated, the cooking vessel is `in the form of a coiee pot 33 havmg a handie 35 through which extends a downwardly directed tube 37. As shown, the tube 37 opens into the coffee pot adjacent its top through a port 39, While the tube terminates at its lower end at a point above the bottom of the coffee pot. As will be obvious, when steam is generated in the cooking vessel, a jet ofA steam will discharge downwardly from the lower end oi the tube 37, and to facilitate this the spout 41 of the pot is herein provided with a lid 43 hinged at 45 and so constructed as to prevent escape of steam from the spout during normal boiling of the contents of the pot without inter- IUU fering. with the pouring of such contents through the s ut.

As shown, neath the top of thel range is a casting or the like 4 7 havin a horizon.- tal bore 49 o en at one end an intersected by a vertica bore 51. As shown, a short tube 53 is provided for extending the bore 51 to above the top of the range, this tube being readily removable from the bore 51, and the latter being provided with a shoulder 55 for determining the extent of pro'ection of the tube thereinto. As willbe o vious, when steam'is generated in the pot 33 a jet of steam will pass through the tube l37, tube 53, bore 5l, and bore-49 and discharge to the atmosphere through the open end 50 of the latter, while if the lid 57 of the pot is raised a current ofv air will enter -the open end 50 of the bore- 49 yand pass upwardly through the bore 51, tube 53, and tube 37. l

As herein illustrated, the bore 49 contains a thermostatic element 59 which in ay be of any suitable type, but as herein lndlcated is a coiled bi-metallic strip ixedly supported at one end 61 to a switch casing 63, and at its opposite end 65 connected to a rotary shaft 67 which extends into this switch casing. As shown, the casing 63 closes one end of the bore 49 and supports or forms part of the casing of the controlling switch '9.

As illustrated, the thermostatic element' 59 o erates a switch 69, schematically shown in igs. 3 to 6, this switch herein being placed in the lead 26 which connects the terminal 25 of the high capacity resistor 7 to the switch contact 13, so that o ening and closing of the switch 69, with t e parts in the position shown by Figs. 5 and 6, will be effective to establish or interrupt flow of current through the high capacity resistor 7.

Herein that end of the shaft 67 which is within the casing 63 has rotatably mount-- ed thereon an arm 71 of insulating material, the lower end of said arm carrying a pair of pins 73 between which extends one end of a leaf spring 75, theopposite end of which is rigidly connected to the end of the shaft 67. As shown, the arm 71 has interally formed therewith a lateral projection 6 which pivotally supports at 77 a metal block 78 cooperating with a pair of contacts 79, the latter mounted on a block 81 of insulating material and having theterminals 82 to permit the switch to be placed in the lead 26, as schematically indicated at 69 in Figs. 3 to 6. As shown, the upper end of the arm 71 is provided with a rounded projection 83 cooperating with the downwardly projecting cam surface 85 formed by the reversely curved end of a leaf spring 87, the latter secured at its opposite end to the peripheral wall of the casing 63.

The position of parts shown by Fig. 2 is that which exists when the thermostat is.

.Any

cold. If under these conditions the pot-boils, and the thermostatic element is heated,

latter will tend to uncoil and rotate the shaft 67 clockwise, as viewed in Fig. 2. This clockwise rotation will flex the spring 75, .and when the alfort exertedwby this spring on the arm 71 overcomes lthe resistance oered by the' spring 87 to clockwise rotation of the arm, the rojection `83 will sna past the downward y-projecting cam l sur ace 85 and cause the plate 78 to move out 4tion of parts/indicated by 5 and 6.

When the thermostatic switch 1s o and the thermostatic element cools and t us tends to coil up, the spring 75 will be put under suicient flexure to snap the arm 71 into the position of parts illustrated by Fig. 2. further counter-clockwise movement of the shaft 67, after the thermostatic switch is closed, will result only in lexure of the spring 75, and the same is true of clockwise movement after the switch. is opened and the arm 71 is brought up against the stop'- 89. It will thus be observed that the spring 75 not only acts to cause a snap action of the thermostatic switch, but pre` form of thermostat disclosed is only one example of numerous thermostats that may be employed, also that the resistance heating element may consist of various arrangements o resistors controlled by the main switch in any desired manner. Preferably,

however, the resistance heatin Velement is so constructed and,so controlla Ab the main switch that operation' of the t ermostatic switch into open position will permit suficient heat being generated to maintain a low temperature conditio 4when the main controlling switch is in the position in which the heating element generates the maximum heat. It will also be understood that other deviations from the specific embodiment .of the invention herein disclosed may be made without departing from the spirit of the invention.,

I claim:

1. An electricy range for cooking vessels having, in combination, an electric heating element, a frame carrying said heatingY element, a vertically directed flue for connection to a cooking vessel,`s aid flue being carried by said frame and having open ends, a thermostatic switch for controlling current flow through said heating element, said -element in said iue, an

thermostatic switch having a heatI sensitive element in said ue.

2. An electric range` for vessels having, in combination an electric heating element, a frame ca said heating element,.a vertically directed iue for connectionl to a cooking vessel said iue being carried by said frame and having o n ends, a thermostatic switch for contro 'ng current flow through said heating element, said thermostatic switch havin a heat sensitive connections between said thermostatic switch and said heating element for causing ascending air currents thro heatin ei'ect of said heating element and deseen 'n steam currents to -decrease the heatinge ect of said heating element.

3. An electric range for cooking vessels having, in combination, Aa frame, an electric heating element at the upper side of said frame, a vertically directed iiue for connection to a cooking vessel, 'said flue -ha open ends and be' carried by said frame, the lower end of sai flue bein at the under side of said frame below sai heating element, a thermostatic switch for controlling current flow through said heating element, said switch having a heat sensitive element in saidflue, and connections between said switch and said heating element for causing ascending air currents throu h saidiiue to increase the heatingeiiect o said heating element and descendin steam currents to decrease the heating eect of said heating element. l'

4. An electric range for cooking veels having, in combination, a frame, an electric heating element carried bg said frame, a thermostatic switch carrie by said frame .for controlling current flow through said heating element, said switch having a heat sensitive element at the under side of said frame below said heating element, and av vertically directed open-ended iue for connection to a cooking vessel, said ue carried ,by said frameand arranged to direct ascending air currents and descend currents against said heat sensitive e ement.

In testimony whereof, I have signed my name to this specification.

` CLARENCE D. STARR.

ugh said iiue to increase the' steam Y

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