US1209862A

US1209862A - Electric heating appliance.

Info

Publication number: US1209862A
Application number: US7289216A
Authority: US
Inventors: Tiodolf Lidberg
Original assignee: Chicago Surgical & Electrical Co
Current assignee: Chicago Surgical & Electrical Co
Priority date: 1916-01-19
Filing date: 1916-01-19
Publication date: 1916-12-26
Anticipated expiration: 1933-12-26

Description

T. LIDBERG.

ELECTRIC HEATING APPLIANCE.

APPLICATION FILED JAN-19,1916- Patented Dec. 26,1916.

zap 22%,

UNITED STATES PATENT OFFICE.

'IIODOLE LIDBEBG, OF CHICAGO, ILLINOIS, ASSIGNOR. TO CHICAGO SURGICAL & ELECTRICAL COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

ELECTRIC HEATING APPLIANCE.

Specification of Letters Patent.

Patented Dec. 26, 1916.

To all whom it may concern Be it known that I, TIoboLr LIDBERG, a citizen of the United States, residing at Ohicago, in the county of Cook and State of Illino1s, have invented certain new and useful Improvements in Electric Heating Appliances, of which the following is a specification.

My invention relates to improvements in electric heating appliances and has especial reference to devices of this character, wherewith to produce and to maintain constant temperature within an area to be heated.

One of the objects of my invention is to provide an appliance especially adapted for heating a liquid bath to maintain it at a substantially constant temperature, under varying extraneous atmospheric conditions, and especially adapted for maintaining a water bath at a constant temperature, within a very small variation, such as used in bacteriological research, in which the culture tubes are required 'to be kept for periods of time at selected temperature, without material change.

Another object of my invention is to generally improve appliances of this character to render them accurate and reliable; to reduce the cost and to simplify their construction.

Other and further objects of my invention will become readily apparent, to persons skilled in the art, from a consideration of the following description when. taken in conjunction with the drawings, wherein Figure 1 is an elevation of the appliance and a water bath showing parts in section. Fig. 2 is a transverse section taken on line 22 of Fig. 1. Fig. 3 is a transverse section taken on line 3-3 of Fig.1.

In all the views the same reference characters are employed to indicate similar parts. In the drawings 5 is a vessel containing a Wvater bath 6, which it is desired to maintain at a constant temperature. The electric heater 7 comprises an electric heating coil 8 wound back and forth upon pins 9 that are driven into a wafer-like disk of insulatingmaterial 10. The heating'unit is placed within a liquid tight envelop or casing 11 and surrounded by a suitable mastic insulating mass 12. A verticall extending conductor carrying tube 13 1s secured to the casing 11 by means of a nut 14, or in any other suitable manner. Upon the upper end of the tube 13 is a cruciform fitting 15, provided with insulating bushings 16 and 16'. The tube 13 enters the opening in the extension 17, of the fitting 15, and a lamp socket 18 is screwed into the extension 19 of the fitting. An indicating lamp 20 is screwed into the socket 18. A thermo-responsive device 21, for controlling the heater, consists of a tube 22, closed at its lower end, as at 23, and secured to the tube 13, as by the clamp 24. The bushing 25, of insulatingmaterial serves as a closure for the upper end of the tube 22. From the bushing 25 is suspended a rod 26 which is only slightly shorter than the entire length of the tube 22. The screw threaded portion 27, of the rod, makes electrical contact with the screw threaded bushing 28, in which the wire 49 is to be inserted and clamped by the screw 30. A similar terminal bushing 31, is diametrically opposite the bushing 28, and is held in place by a screw 32 which supports a bracket 33. A bell-crank lever 34 is pivoted to the bracket 33, as at 35, and is provided with a laterally extending arm 36 and with a downwardly extending arm 37, which latter carries a contact 38. A spring 39 yieldingly maintains the arm 37 in position substantiall central of the tube. 22. The normal position of the contact 38 of the arm 37, however, is determined by an adjusting screw 40 which asses centrally through the bushing 25 and 1s provided with a reduced end, 41,-which engages the arm 36 of the lever 34. The screw 40 is threaded into an insert metallic bushing 42, which is securedaxially'of the bushing 25. A check nut 43 holds the screw 40 in adjusted position and athumb turned, knurled head 44 is the means by which the screw may be rotated for the purpose of adjusting the position of the contact 38, on the arm 34.

On the lower end of the rod 26, is a. lug 45 to which a thermostatic expansion bar 46 is secured, as by screws or rivets 47. The bar 46 carries on its free'end a contact 48, which electricallyconnects with the contact '38, on the arm 34.

Wires 49 and 50 are intended for connection with a suitable source of electric current. The wire 49 is inserted in an opening in the bushing connector 28 and clamped in place by screw 30. The wire 50 is connected to the vertically extending wire 51, as at 52, the downwardly extending branch being connected to the terminal 53, of the heater wire 8. The upwardly extending branch 51 of wire 51 is connected to one terminal of the socket 18 in which the signal lamp 20 is contained. A wire 55 is connected at one end in the bushing connector 31, of the regulator and at its other end to a vertical wire 52 positioned Within the tube 13. The Wire 52 is connected at its lower end to the terminal 53 of the heating coil 8, and its upper end 53, is connected to a terminal of the lamp socket 18.

The operation of the device is as follows z-VVhen the heater 7 and the regulator 21 are placed in a water bath, 6, as shown in Fig. 1, the contacts 38 and 48 are together and the circuit is thereby closed through the heater conductor 8 and the lamp20 in parallel. The circuit connection between the contacts 38 and 4&8 will remain closed until the temperature of the water 6 has been raised sufficiently to cause the bar 46 to expand laterally and break connection between said contacts. At this time the lamp 20 will be extinguished and the current will be withdrawn from the heating coil 8. When the temperature of the bath decreases, or

tends to decrease, the bar 46 will contract into its original position until connection 1s again established between the contacts 38' and 48 and the circuit will be thereby closed and the current will again How through the heater coil 8 to raise the temperature of the water. The temperature of the waterbath may be varied by turning the screw 40. When it is turned to the left, the screw end 41 is raised so that the contact 38 may be moved further over toward the opposite side of the tube 22 by the spring 39. Contact 48, on the expansion bar 46, will then break connection with contact 38 at a lower temperature. The spring 39 holds the arm 36 of lever-34z at all times in contact with the end of screw 40 so that upward and downward movement of the screw is converted into sidewise movement of contact 38. lit a higher temperature in the bath 6 is desired, the screw is manually rotated to the right and the contact 38 is moved over toward the left, and the expansion bar is thus put under greater tension, requiring higher temperature to cause it to break connection between contacts 38 and 48.

The tube 22 is substantially air tight and, therefore, the air within the tube, that is heated by the water cannot escape and the expansion bar 46 is therefore heated to a uniform temperature, substantially throughout its entire. length, partly bycirculation of air within the tube, thereby rendering it very sensitive to changes of heat, and causing it to respond instantly to the slightest variation thereof,

naoaeea The casing 11, containing the heater 10,

is made fiat and of large diameter so as to serve as a base support for the device, and resting upon the floor of the container 5 it is in the best location for the purpose of heating the liquid contained therein.

Having described my invention, what I claim is 1. Tn a portable electric heater, the combination of a relatively broad flat casing, a heating coil inclosed therein, a conductor carrying tube projecting upwardly from: the casing, and a thermostatic controller supported by the tube.

2. Tn a portable electric heater, the combination of a relatively broad flat casing, a heating coil inclosed therein, a conductor carrying tube projecting upwardly from the casing, a substantially air-tight tube supported by the first mentioned tube, and a thermostatic controller contained within the last mentioned tube.

3. In a portable electric heater, the combination of a relatively broad fiat casing, a heating coil inclosed therein, a conductor carrying tube projecting upwardly from the casing, -a substantially air-tight tube sup ported by the first mentioned tube, and e2rtending downwardly to a point adjacent the flat casing, a thermostatic controller contained within the last mentioned tube, and an electric circuit connecting the heating coil and thermostatic controller in series.

1. A device of the character described comprising a heater provided with a relatively broad flat heating element; a vertically disposed tube extending therefrom; an indicating lamp, mounted on the top of the tube; in combination with, a thermoresponsive device, for controlling the heat produced by said heater, said thermo-responsive device comprising a closed tube, parallel with the heater tube and connected thereto; an expansion bar carrying a contact, and a cooperating contact, within the latter tube; a screw at the top of the latter tube to adjust the position of the coiiperating contact, and wires passing through the heater tube to connect said thermo-responsive device and lamp in circuit with said heater.

5. A. device of the character described comprising an electric heater element; a vertically disposed tube connected .therewith; a cruciform fitting on the upper end of the tube a socket for a lamp mounted on one arm of the fitting, conducting wires extending through the horizontal arms of the fitting; branch wires in said tube connecting said lamp and heater element in parallel connecting said switch in series with said 1.30

heater and said lamp to extinguish the lamp when circuit through the heater is thereby opened.

6. A device of the character described comprising a heater provided with a heating element; a tube extending therefrom; an indicating lamp mounted on the tube; in combination with, a thermo-responsive device, for controlling the heat produced by said heater, said thermo-responsive device comprising a closed tube, connected with the heater tube; an expansion bar carrying a contact, and a cooperating contact, within the latter tube; a screw on the top of the latter tube to adjust the position of the cooperating contacts, and wires passing through the heater tube to connect said thermo-responsive device and lamp in circuit with said heater.

7. A device of the character described comprising a heater provided with a heating element; a tube extending therefrom;

an indicating lamp, mounted on the tube;

in combination w1th, a thermo-responsive device, for controlling the heat produced by said heater, said therr'no-responsive device comprising a closed chamber, connected with the heater tube; an expansible member carrying a contact,'and a cooperating contact, within the chamber; means projecting outside of the chamber to adjust the position of the cooperating contact, and wires passing through the heater tube to connect said thermo-responsive device and lamp in. circuit with said heater.

In testimony whereof I hereunto set my hand in the presence of two subscribing wit nesses.

TIODOLF LIDBERG. In the presence of- FoRfiE BAIN, MARY F. ALLEN.