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Publication numberUS901871 A
Publication typeGrant
Publication dateOct 20, 1908
Filing dateFeb 21, 1908
Priority dateFeb 21, 1908
Publication numberUS 901871 A, US 901871A, US-A-901871, US901871 A, US901871A
InventorsGeorge N Blanchard
Original AssigneeGeorge N Blanchard, Electric Mfg Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Electric heater and drier.
US 901871 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)




901,871. I Patented Oct. 20, 1908.




No. eoi,e71.

Specification of Letters Patent.

Patented Oct. 20, 1908.

"a iicatibn'meareb 21, 1908. Serial m. 417,077.

To all whom it may concern:

Be it'known that I, GE0RGE N. BLANCHARD, citizen of the United States,.residing in the city and county of San Francisco and State of California, have invented new and useful Improvements in Electric Heaters and Driers, of which the following is a specification.

My invention relates to an apparatus for producing currents of hot air for therapeutic and various other or similar uses where hot air is required.

It consists in the novel construction and disposition of the electrical resistance coil through which air is driven for the purpose of heating the same, and in details of construction which will bemore fully explained by reference to the accompanying drawings, in which Figure 1 is a side elevation, partfyin sec-, tion, of the device. Fig. 2 is a perspective view of the resistance coil. Fig. 3 is an end view of tube and coil. Fig. 4 is a transverse f section of a coil.

Various devices have been em loyed forv heating a current of air to be su sequently used 5 such devices usually including electrically resistant wires of small diameter so disposed that currents of air may.- be passed over these wires, which being heated by the electrical current will impart the heat to the vair which is passing. 4

D'fiiculty is experienced in maintaining an equabletemperature of the heating wires, and at the same time utilizing to the fullest extent their heating ability.

Within a suitable case, C, the fan, A, is adapted to operate throughpower communicated thereto from any well known type of electric motor, B, shown by dotted lines in Fig. 1 said fan case having a discharge pipe or passage through which the blast of air is driven. This passage may be round or rectangular as shown,

The heating coil consists ,of'fine wires 3 which are wound upon a pyramidal shaped supporting frame having a base adapted'to fit the rectangular passage 2. This base may be constructed of any suitable material, and i ductor, such as lava. The wires 3 are wound over the edges. of these plates which are notched or toothed sothat each winding of wire will be kept separate from the next adjacent one, and each winding will form a ing from the smaller to the larger end. When thus wound, the ends of theseresistant wires are respectively connected with conducting wires 5, through which a current "In my be passed, and the current being in excess of the capacity of the wires 2, the wire will be heated to as high a temperature as may be desired. This resistance coil being completed, is then inserted into the rectangular tube 2, the edges of' the cross plates at their largest dimension fitting into the angles of the tube, and the resistance wires 2 which are wound upon the largest portion ofthis frame are substantially close to the opposite end, the wires ofthis coil arenear to the center.

It has been found that Where coils of wire are disposed longitudinally within an airconveying tube, and these coils of substantially the same diameter, .the air striking and the coil at this end will be correspondingly cooled. As the heated air passes on through the coil, its temperature rises, and near the discharge end it becomes so high, that the coil itself will be unduly heated at this end; thus the coil will have a comparatively low temperature Where the air first strikes it, and a high temperature where the air is leaving it.

I If the wires are simply disposed transversely of the passage in a single' plane, it would not be possible to insert a sufficient length of resistance wire choking the air passage.

By my invention the whole surface of the resistance wire is uniformly subjected to the cold blast of air from the propelling fan, at

shape of the resisting unit, a suflicient length of resistance wire can bensed, with ample space between the turns of said resistance. wire to admit of free passage of air.

The rectangular or pyramidal form of the from the conducting tube. v

The fan case may be provided with a suitthe first coil will commence to be heated,

, without unduly the same time on. account of the pyramidal coil, renders it easy to insert and remove rectangle; theserectangles gradually enlarg- '1' inner periphery of the tube, while at the able handle D whereby the device may be freely moved about so as to dry the parts to be subjected to the current of air.

Having thus described my invention, what I claim and desire to secure by Letters Patent is 1. In an air-heating apparatus, an airforcing mechanism, a discharge tube, and a pyramidal electrical resistance coil fixed within said tube.

2. In an apparatus of the character described, anair discharge passage, a resistance coil, consisting of wires wound upon a divergent or pyramidal insulated frame, and located in said passage.

3. In an apparatus of the character described, an air discharge passa e, a frame having insulated edges adapted coiled thereon, and gradually divergent from one end to the,other,'said frame being fitted in the air discharge assage, and electrical currentconnections with the resistant coil.

In testimony whereof I have hereunto set .my hand in presence oftwo subscribing witto receive naked electrically resistant wires which are a

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2997569 *Oct 2, 1958Aug 22, 1961Vorwerk & Co Elektrowerke KgElectric hot air douche
US4225775 *Dec 15, 1978Sep 30, 1980General Electric CompanyHair dryer
US6141495 *Jan 10, 2000Oct 31, 2000Roth; AsherPortable flue heater to reduce or eliminate downdrafts
US20100111510 *Sep 26, 2007May 6, 2010Kam Tao LoEnergy-saving electrothermal blower and a manufacture method of the electrothermal element thereof
International ClassificationA45D20/10
Cooperative ClassificationA45D20/10
European ClassificationA45D20/10