US2014211A

US2014211A - Electric drier

Info

Publication number: US2014211A
Application number: US717742A
Authority: US
Inventors: Otto R Schurig
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1934-03-28
Filing date: 1934-03-28
Publication date: 1935-09-10
Anticipated expiration: 1952-09-10

Description

P 1935- o. R. SCHURIG 2,014,211

ELECTRIC DRIER Filed March 28. 1934 2 Sheets-Sheet 1 \nventor": Otto R. schurig,

H i s Attorn egg.

Sept. 10, 1935. O R sc 2,014,211

ELECTRIC DRIER Filed March 28. 1934 2 Sheets-Sheet 2 Otto R. Schgrig,

Haw] 5. him

His Attorney.

I i l J a 19 1 5 1/29 I7 L 1 Inventor:

Patented Sept. 10, 1935 UNITED STATES PATENT OFFICE ELECTRIC DRIER New York Application March 28,

10 Claims.

This invention relates to electric driers, more particularly electric hand driers, and has for its object the provision of control means for automatically varying the temperature of the heated drying air.

More particularly my invention relates to electric hand driers wherein a current of heated air is blown over the hands. Heretofore the maximum air temperature has been limited to, for example, 120 deg. F., so as to avoid an uncomfortably hot feeling at the end of the drying operation. However, air at this temperature when applied to the wet hands produces a disagreeably cool feeling. In accordance with my invention, therefore, I provide a current of air heated initially at a relatively high temperature such as 180 deg. E, which temperature gives a feeling of warmth at the beginning of the drying operation. Thereafter the temperature of the air is automatically reduced, for example after 15 or 20 seconds, to the drying temperature of 120 deg. F. forthe completion of the drying operation.

In carrying out my invention in one form, I provide a motor driven blower or fan for circulating the drying air over an electric heating resistor, together with means for giving a low motor speed at the beginning of the drying operation, so as to give a high air temperature, and means for automatically increasing the speed of the motor after a predetermined time interval whereby a larger volume of air is circulated with consequent lower temperature.

For a more complete understanding of my invention, reference should be had to the accompanying drawings, Fig. l of which is a front elevation view of a pedestal-type electric hand drier embodying my invention; Fig. 2 is a side elevation view of the device shown in Fig. 1; Fig. 3 is a vertical sectional view of the drying mechanism 4 utilized in the device shown in Figs. 1 and 2, and

taken along the line 3-3 of Fig. 4. Fig. 4 is a plan view, partly in section, of the drying apparatus. Fig. 5 is a front elevation view of the timing control means, while Fig. 6 is a diagrammatic representation of the control circuits for the motor.

Referring to the drawings, I have shown my invention in one form as applied to a pedestaltype hand drier of conventional construction. The mechanism for circulating and heating the air is contained in a metallic casing l0 mounted on a pedestal I I. This mechanism may be started and stopped by means of a foot pedal l2 mounted on the base of the drier. The heated air is directed outward through a nozzle l3 which 1934, Serial No. 717,742.

is pivotally mounted in the casing [0, so that it may be moved up and down for convenient adjustment in height.

Referring to Figs. 3 and 4 of the drawings, the air is circulated by means of an electric motor l4 provided with a centrifugal-type fan 15. This motor is mounted in a suitable position in the casing ill, for example on a bracket l6, and at one side of the nozzle l3. On the opposite side of the nozzle is an electric resistance heater M. This heater as shown comprises a helical resistance conductor l8 which is wound on electrically insulating supports l8a. These supports are shown as strips of insulating material, such as mica, four being shown spaced equal distances apart around the axis of rotation of the motor, and converging somewhat toward each other at the end adjacent the nozzle. The supporting strips l8a are furthermore mounted in a cylindrical casing 19. 20

As shown, the nozzle l3 communicates with a cylindrical housing20 having an opening 2| at one side, into which a circular boss 2la, on the end frame of the motor, extends. The casing 20 is thereby pivotally mounted on the motor 25 frame, it being closed on that side by the motor frame. The housing 20 is also provided with an opening in its opposite side'around which is an external flange member 22 forming a support for the cylindrical heating casing 19. It will thus be 30 observed that the nozzle and its casing 20, together with the heating unit, are pivotally mounted on the boss 2 la.

The fan I5 is shown as cylindrical in shape, having the end adjacent the motor closed and 35 provided with a hub 25 which is secured to the shaft of the motor. The fan on its periphery is provided with a plurality of radially extended blades 26. It may be constructed, for example, from a cylinder of sheet metal, the blades 26 being formed by striking tabs of the metal inwardly at suitable intervals. The open end of the fan lies closely adjacent the side wall of the casing 20 and registers with the opening in the casing. It will be observed that rotation of the fan tends to throw the air outwardly, whereby air is drawn in over the heater, through the casing l9 and forced out through the nozzle IS. A suitable air inlet opening 21 to the casing I0 'is provided around the upper end of the pedestal I I.

Referring to Fig. 6, the heating unit I1 and the driving motor M can be connected to a suitable source of electrical supply 28 by means of a switch .29 which is operated by the foot pedal l2. As shown, the switch is connected through a pivoted arm 30 and a link 3| to the pedal. The switch is furthermore biased to its open position by means of a spring 32 encircling the rod 3|, and having its upper end bearing on a fixed member 33 secured to the pedestal, and its lower end bearing on the pedal.

The motor I4 is connected in parallel with the heating unit I! in the arrangement shown. Included in circuit in series with the motor is a resistance 35 which gives a reduced operating speed for the motor. The motor may be of any suitable type, preferably adapted for both A. C. and D. C. operation such as used on conventional fans. For example, it may be a series motor.

For the purpose of short-circuiting the resistance 35 or a portion of it after a predetermined time interval to thereby increase the speed of the motor, I have provided suitable timing means which, in the iorm shown in Fig. 6, comprises a bimetallic thermostat 38 provided with a heating resistance 31. The thermostat 36 carries on its free end a switch contact 33 which is moved upon the warping of the thermostat in response to an increase in temperature into engagement with a stationary contact 39. The engagement of these contacts closes a circuit for an operating coil 40 which when enregized operates the two switch contacts 4| and 42 to their uppermost positions. The switch contact 4| closes a shunt circuit around the resistance 35 or a suitable portion 01' it, whereby resistance is out out of the motor circuit, while the switch contact 42 opens the circuit the thermostat heater 3! whereby the heater is disconnected from the supply source and closes a holding circuit for the operating coil 40.

It will be understood that when the switch 28 is closed by depressing the foot pedal, the motor is started with the resistance 35 in series with it, and therefore operates at a relatively low speed such as 1000 R. P. M., whereby the air is circulated at a lower rate and consequently is heated to a relatively high temperature such as 180 deg. F. Concurrently with the starting of the motor, the thermostat heater 31 is connected to the supply source, this connection being through the conductor 45, the switch contact 42 in its lowermost position, the resistance 31 and conductor 46 back to the other side of the supply source. The resistance 31 is therefore heated and imparts its heat to the thermostat 36, thereby causing the upper end 01' the thermostat to move the contact 33 toward the contact 39.

Finally, after the expiration of a predetermined time interval for which the thermostat and heating coil are constructed and arranged, the contact 33 will engage the contact 39 and thus close the circuit of the operating coil 40. This circuit leads from one side of the supply source through the conductor 43, the coil, contacts-33 and 39, the thermostat 36 and the conductor 48 back to the other side or the supply source. This short-cir cuits the resistance 35 or a predetermined portion of it, establishes a holding circuit through the switch contact 42 in its uppermost position and

conductors

45 and 48 for the coil 40, and opens the circuit to the heater 31 by means of the switch contact 42. The motor then operates at a predetermined high speed such as 3600 R. P. M. and circulates the air over the heater at a higher rate of flow so that a larger volume of air is circulated with consequently reduced temperature such as 120 deg. F.

While any suitable switch 29 may be used, prererably a snap-type switch is used. As shown in Fig. 4, the switch 29 is provided with over-center springs 48 to give it a snap action irom one position to the other.

It will be understood that the shunt circuit for the resistance 35 controlled by the switch 4! may have connections with any predetermined portion or the whole of the resistance as required to give a desired high motor speed for the supply voltage available.

Obviously it desired the thermostat 36 may be adapted to be heated from the motor resistance 35 in which case the resistance 37 and the lower contacts oi the switch 42 in circuit with the resistance 31 can be eliminated. The thermostat would then be placed in suitably good thermal relation with the resistance 35.

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

1. The combination in a hand drying device, of an electric heater, means for circulating drying air over said heater at different rates of how, and timing means for controlling said air circulating means to vary the rate of flow of air over said heater after a predetermined time interval.

2. The combination in a hand drylngdevice, of an electric heater, means for circulating drying air over said heater at an initial low rate whereby the air is heated to a relatively high 8 temperature, and timing means for controlling said air circulating means to increase the rate of how of air after a predetermined time interval whereby the air is heated to a relatively low temperature.

3. The combination in an electric hand drying device, of an electric heater, means for circulating drying air over said heater whereby the air is heated, means for operating said circulating means to give a low rate of flow of air over said heater at the beginning or the drying operation whereby the air is heated to a relatively high temperature, means for increasing the rate of flow of air, and means set in operation upon the initiation of the drying operation for operating 45 said means for increasing the rate of flow of air after a predetermined time interval to thereby give a lower air temperature for the completion of the drying operation.

4. The combination in a hand drying device air over said heater, a driving motor i'or said over said heater, means for controlling the rate of flow of air over said heater, and timing means ior operating said rate of flow controlling means a predetermined time interval after said air circulation means is started to thereby give a different air temperature.

5. The combination in a hand drying device of an electric heater, fan means for circulating air over said heater, a driving motor for said Ian means, a switch for controlling said motor, and timing means set in operation by the operation of said switch to start said motor for varying the speed of said motor after a predetermined time interval to thereby cause the air to be heated to diilferent temperatures.

6. The combination in a hand drying device of an electric heater, a blower for circulating air over said heater, a driving motor for said blower, a switch for controlling said motor, means for causing said motor to operate at a low speed whereby the air is heated to a relatively high temperature during an initial stage of the drying operation, and means set in operation at the beginning or the drying operation for thereafter increasing the speed of the motor to circulate a larger volume of air at a lower temperature to complete the drying operation.

7. The combination in a hand drying device of an electric heater, a blower for circulating air over said heater, a driving motor for said blower, a switch for controlling said motor, speed control means for causing said motor to operate at a low speed upon the closure of said switch whereby the air passing over said heater is heated to a relatively high temperature during the initial stage of the drying operation, and timing means set in operation upon the closure of said switch for operating said speed control means to increase the speed of the motor after a predetermined interval of time and thereby circulate a larger volume of air at a lower temperature to complete the drying operation.

8. The combination in a hand drying device of an electric heater, a blower for circulating air over said heater, a driving motor for said blower, a switch for controlling said motor, speed control means for causing said motor to operate at a low speed upon the closure of said switch, a

thermostat for operating said speed control means, a heater for said thermostat connected to be energized with said motor whereby said thermostat operates said control means to increase the speed of said motor after a predetermined time interval.

9. Automatic time control means for an electric hand drying device provided with a motor for circulating drying air, comprising a resistance for connection in circuit with said motor to 10 reduce its speed, a switch for short-circuiting said resistance, and timing means for operating said switch a predetermined time interval after the starting of the motor.

10. Automatic time control means for an eleo- 15 tric hand drying device provided with a motor for circulating drying air, comprising means for varying the speed of the motor, a switch for controlling said speed varying means, and an electric timing device arranged to be energized con- 20 currently with the motor for operating said switch a predetermined time interval after the starting of the motor.

OTTO R. SCHURIG.

CERTIFICATE OF CORRECTION.

Patent No. 2,014,2l1. September 10, 1935.

OTTO R. SCHURIG.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2. second column, line 5i, claim 4, strike out the words "air over said heater, a driving motor for said" and insert instead of an electric heater, means for circulating air; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 8th day of October, A. D. 1935.

Leslie Frazer (Seal) Acting Commissioner of Patents.

CERTIFICATE OF CORRECTION.

Patent No. 2,014,211. September 10, 1935.

OTTO R. SCHURIG.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2. second column, line SI, claim 4, strike out the words "air over said heater, a driving motor for said" and insert instead of an electric heater, means for circulating air; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 8th day of October, A. D. 1935.

Leslie Frazer (Seal) Acting Commissioner of Patents.