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Publication numberUS427574 A
Publication typeGrant
Publication dateMay 13, 1890
Filing dateDec 28, 1889
Publication numberUS 427574 A, US 427574A, US-A-427574, US427574 A, US427574A
InventorsBenjamin Chew Howard
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Electric heater
US 427574 A
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Description  (OCR text may contain errors)

(No Model.)





SPECIFICATION forming part of Letters Patent No. 427,574, dated May 13, 1890.

Application filed December 28, 1889. Serial No. 335,213. (No model.)

To all whom itmftg/ concern:

Be it known that I, BENJAMIN CHEW HOW- ARD, a citizen of the United States, residing at Baltimore, in the State of Maryland, have invented certain new and useful Improvements in Electric Heaters; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the let-` ters and figures of reference marked thereon, which form a part of this specification.

Myinvention relates to devices for heating air for warming dwelling-houses, stores, public buildings, railroad-cars, steamboats, and other habitations.

rlhe obj eet of the invention is to accomplish this result in a safer and more economical mode than has been done heretofore and place the heating appliances under complete control of the attendant. I attain these results by employing electricity as the heating agent, causing it to pass through suitable resistancecoils, through which the air to be warmed is drawn, preferably by a fan driven by an electric motor.

In the accompanying drawings, which represent one mode of carrying out my inven tion, Figure l is a longitudinal section of the heating apparatus, Fig. 2 is an enlarged view of one of the screens incomplete. Fig. 3 is a diagram of the electrical circuits and connections. Figs. 4 and 5 are views of the switch, and Figs. G and 7 illustrate in diagram two arrangements of the winding of the screens.

The same letters and numerals refer to the same part-s in all the figures.

\Vithin an inclosing-jacket A, preferably of sheet metal, is arranged a tube B, prefern ably of non -conducting material, such as earthenware. It may be of any desirable cross-sectionand of a length and diameter proportionate to the service it is to perfornr The outer end of the tube B is united air tight t0 the jacket A; but elsewhere it is preferably somewhat smaller than the jacket in order to provide an air-space cl. around it, suitable supports b being provided to retain the tube in place. The airspace is not, however, an essential. feature 'and the jacket may be omitted. At or near the mouth of the tube there maybe a netting b', to prevent the entrance of anything but air. The inner end of the jacket or of the tube communicates with a delivery-flue O, by which the air passing through the apparatus is conveyed to the desired place. A netting cmay be arranged at the entrance of the fine.

IVithinthe tube B, I place a set of resistance-coils D. I have shown six coils in the drawings, but any number may be used that experience and the exigeneies of the service may demand. The coils may consist of flat screens composed of fiat or round uninsulated wire wound in parallel lines back and forth across an open frame d, each frame holding, preferably, three layers d cl2 cl3, the wires in one layer running in a diiferent direction from those in the other layers, as clearly shown in Fig. 2. The several layers may be connected in series, as indicated in Fig. G, or two of them may be in parallel circuit with each other and the pair in series with the third layer, as in Fig. 7.

The frames (Z are tted into the tube B at suitable distances apart, and the coils are con nected up to a switch-board E, preferably in the manner shown in Fig. 3. Screens I and 4 are here shown in series, and also screens 2 and 3, while screens 5 and 6 have independ* ent connections and may be wound with finer wire to give a higher heating effect than the first four. These last two are intended to be used only in case of extremely cold weather or when the apartment is to be quickly heated.

Any suitable switch-board may be used and the connection may be made otherwise than as specified above, if desired. A convenient form of switch is shown in Figs. I and 5. Fastened upon an insulating-base F are pairs of spring-clips ff f2 fil, dsc., which are connected, respectively, with the wires c c c2 c3, dse. Mounted on ashaft is a segment G, composed of metallic faces g g', suitably insulated from each other. The main conductors X Y are connected, respectively, with the upper and lower clips f -by means of the wires e. When the segment G is turned to enter between and form contact with the two pairs of clips j' f', the current will [iow through the coils l it. If the segment G is turned to engage the next pair of clips f 2, the coils 2 and ICO 3 will be thrown into circuit, and so on. The coils will be cut out in reverse order upon turning the segment backward. A handle G outside of the box E affords aread y means of manipulating the segment.

The draft of air through the tube B may depend upon the natural tendency of heated air to rise; but I prefer to render its movement positive by means of a fan H', driven by an electric motor, which is connected with the main conductors independently of the coils.

A switch 7i gives the attendant control of the fan-motor, which is located at any convenient point in the line of the air-current.

lt is obvious that the screens D can be heated to a greater or less deg'ree by a proper system of resistances R in their respective circuits, and that the speed of the motor can be similarly governed. This gives the attendant complete control of the apparatus, and he can regulate the heating el'tect with great nicety. In summer the fan alone can be run to send a current ot' cool fresh air through the flue C.

Havin g thus described my invention, what I claim, and desire to secure by Letters Patent, 1s

l. An electrical apparatus for heating air, consisting' of a tube containing` a series ot resistance-coils, and means tor causing the air to pass through said coils, substantially as described.

2. An electrical apparatus for heating' air, consisting of a tube containing a series of wire screens, means for causing' an electric current to traverse on e or more of said screens, and a flue for conveying away the heated air, substantially as described.

3. An electrical apparatus vfor heating air, consisting of a series of wire screens, suitable connections for conveying a current of electricity to each ot them, and means for regulating the intensity of the several currents, substantially as described.

4. An electrical apparatus for heatin air,

consisting ot' a tube containing a series of resistance-coils, each composed of a frame having a line uninsulated wire wound back and forth across it in parallel lilies, and means for varying the number of coils in circuit, substantially as described.

5. An electrical apparatus for heating air, consisting of a tube containing a series of resistance-coils composed of frames, each having a tine wire wound back and forth across it in two or more layers, the wires in one layer running in a different direction from those in the next, and a switch adapted to vary the number of coils in circuit, substantially as described.

(5. In an electrical apparatus for heating air, the screen D, consisting of an open framed, having a iine wire wound upon it in layers d' d2 cl3, two of which are in parallel circuit, the other being' in series with them, substantially as described.

7. An electrical apparatus for heating' air, consisting of a jacket inclosing a tube, with an air-space between them, a series of resistance-coils in the tube, and a fan for drawing` a current of air through the coils, substantially as described.

8. In an electrical apparatus l'or heating air, a tube B, containing a series of screens D, some of which are wound with liner wire than the rest, substantially as described.

9. In an electricalapparatus Afor heating air, a tube B, containing a series of screens D, connected with a switch-board, whereby the nu mber of screens in circuit can be varied, substantially as described.

l0. In an electrical apparatus lorheatingair, the combination, with the mains X Y, of the screens D and the tanmotor li, and means for controlling them indepeinlently, substantially as described.

ln testimony whereof I afiix my signature in presence of two witnesses.



ALvIN BELT, GEO. l. WHrl."iLnsEv.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2428079 *Mar 4, 1946Sep 30, 1947Hooper Sim MAir-duct electric heater
US3025382 *Mar 9, 1959Mar 13, 1962Eisele William RAuxiliary electrical heating means
US3067316 *May 20, 1960Dec 4, 1962Worthington CorpElectrical duct heater
US4814579 *Apr 7, 1986Mar 21, 1989Innovative Scientific Development, Inc.Electric resistance air reating system for an aircraft cabin
US5925273 *Oct 20, 1997Jul 20, 1999Tutco, Inc.Electric multi-stage heater assembly
US5963709 *May 13, 1997Oct 5, 1999Micropyretics Heaters International, Inc.Hot air blower having two porous materials and gap therebetween
US6141495 *Jan 10, 2000Oct 31, 2000Roth; AsherPortable flue heater to reduce or eliminate downdrafts
US7149416 *Jun 14, 2004Dec 12, 2006Bsh Bosch And Siemens Hausgeraete GmbhClothes dryer heater with air flow increasing device adjacent the heating element
US8249439 *Nov 9, 2006Aug 21, 2012Linde AktiengesellschaftHigh-pressure gas heating device
US20090226156 *Nov 9, 2006Sep 10, 2009Peter HeinrichHigh-pressure gas heating device
Cooperative ClassificationF24H3/0405