US916348A - Electrical heater. - Google Patents

Description

J. A. MEARS, JR. & G. ELLIS.

ELECTRICAL HEATER.

ARPLIOATION FILED APRIL 1908.

Patented Mar. 23, 1909.

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rosnrn ARCHIBALD; MEARS, 1B,, on NEW. YORK, AND; oAnLEfEoN'. ELLLS; or IQABcnMoN'r, f

OF I

NEW YORK, ASSIGNORS TO NATHANIEL: L. FOSTER, TRUSTEE, OF- NEW ROCHELLE.

NEW YORK.

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Application fled Aprilfl, 1908. Serial No. 426,794r.

To it may'concem:

Melina Jr and CARLETON ELLIS, citizens of States, "and iesidents, respec- .tively, of New York and of Larchmont, in .jthe'State of New York, have invented a new and nseful' Improvement in Electrical Heaters, of which the following is a specificat1o;jn'.fi.-

invention relates to electrical heaters especially adaptedfor heating cars,'and re- 'lates particularlyto heaters of a novel type securing perfect ventilation, involving un- Eusjial simplicity and Stability of construction and rigidity of setting all as hereinafter fully set forth; the particular points of novelty being pointed out in the appended claims. I The object of the present invention is to ,20.

supply heater consisting of a spirally coiled wire, spirally arranged on an exceedingly "well ventilated spind e or framework so as to perfectly separate the coils or helices and prov de-for a maximum amount of wire in a minimum of space, and at the same time ar- -ran ing the spindle or framework so that ,Whl 'e' the coil is rigidly sup orted it comes into contact with the spind e or framework x at a few points only, and as the air may cir-' culate freely through the coil and spindle or framework perfect ventilation is secured, so that an unusual amount of heat at a moderate temperature may be generated from a very compact heater. This efiicient heat generation we also aim to develop with the wire at a much lower tem erature than formerly employed. From t e peculiar'construction of our heating device, giving rise to perfect ventllfltlOIl, to a maximum amount of eflective heating surface of the wire and a minimum amount of contact surface We secure results of a highly satisfactory character.

In carrying out our invention, we construct our wire support, bobbin, or spindle, as indicated in the accompanying drawings which represent our invention in somewhat Y diagrammatic fashion and -wl1erein dotted lines. 6

Figure 1 shows in plan view our ventilated spindle.

Fig. 2 is an end elevation of said ventilated spindle. Fig. 3 depicts a vane of insulating material showing the ventilating openings while Fig. 4 is an end elevation with the ventilating openings shown by Fig. 5 is a plan view of the angle-iron having ventilat ng openings co.-

' incidingwith those of the vane or web shown Be'itf known that we, JosEPH'ARomnAm in Figs. 3 and 4. Fi 6 is an end elevation having a portion of the outer casing cut away to show the preferred relative osition of the heating'coils and air vents. *ig. 8 is an end elevation of said assemblage. Fig. 9

is a modified form of said ventilated spindle memenwhla racedepicted in plan view and Fig. 10 is'an end J elevation of said Fig. 9.

. In the drawings, 1 and 2 are angle ironshaving theventilating apertures 3.' These angle irons, four in number, are bolted or clamped so as to support the insulating strips 12. The latter has serrations or grooves regularly spaced in its outer edge.

The insulating strip is preferably made ofthe composition hereinafter described. 'iAs stated the angle-irons and strips are perforated at frequent intervals, as shown at 3, so as to afford ventilating spaces through which the air current rushing upward through the heater may freely pass, thus cooling the wire, extractin heat from-the inner side of the coil, as wel as from the outer. In this manner a far more perfect absorption of the heat, and much better ventilation and greater and more eflicient movement of the air currents, are secured than where the coil is wound on a solid support, such as for instance, .a porcelain tube. Such novel construction effectually provides against the overheating locally of the coil, so that its life is much longer than where non-ventilated supports are employed. The angle irons and vanes are so combined as to leave an opening or passage 4 in which may be passed a long bolt 10 for the purpose of clamping the end frames 7 of the housing or casing 6.

At 5 in Fig. 7 is shown the ire helix spirally arranged on the ventilated spindle and in contact with said spindle at points spaced ninety-degrees apart. '.[he almost entire portion of t 1e helix is therefore availwire support is preferably wound wi h g resistance wire, such for instance, as iron or soft, steel wire, It should be Wound tightly so as to avoid vibration, and the'insnlated stri s of enamel should be tough and thoroug ly non-conductive ofelectricity. By

constructing our heating device in this manner, practically- .allthe surface of the wire is available for heating purposes.

The conversion of electrical energy into heat takes place in accordance with Well known laws. efliciency with which it is absorbed by the atmosphere depend upon the resistance of the coil, u on its length and upon the amount of availa le heat radiating, air contacting surface of the Wire; With a" short coil of ire having an extremely high resistance and a small surface, of course, very high temperatures must needs be employed'to generate the same amount of heat as Where longer coils of Wire of a lower resistance and greater surface are used. Owing to the enormous radiating surface secured by our system of ventilated construction, very moderate tem era tures only are employed and a large vol of air is heated thus securing high heating efiiciency, and rendering the Wire resistant to the crystalliz'ing influences which prevail when higher temperatures are employed.

, A suitable composition for making the insulating strip above indicated, is made by mixing long fibered asbestos withoxid of 'zinqbrrium'chlorid and zinc sulfate. This mixture is moistened with water and pressed into shape. When it solidifies a highly insulating compound is produced. Other bindin materials for the asbestos may be similai ly employed. I

A useful enamel for coating the supporting surfaces of the spindle is secured by mixing two parts of round .glass, one part of zinc oxid, one-ha part of lime and one part feldspar, ap lying this mixture by means of an aqueous'so ution of glue or dextrin, or the like, to the surface to be enameled, and heating the s indie until the enamel fuses, when thes in le is slowly cooled to allow annealing 0 anges to progress to completion, When the spindle is then ready,to be Wound with the spiral helix.

The above described insulating composition or' enamel provider-Jinn 'efiicient and permanent insulating strueture which Withstands hard usua'ge Without 'crac'klng or chipping, thereby effectu ally preventing short circuiting and consequent loss of energy.

Having described our invention,

The heat developed and theurne to the details of which we of course do notlimit' our} selves, but claimsuch modifications therefor as We are entitled to under the dbctrineof equivalence, What We claim as ourjlinvention and desire to secure by Letters Patent, is

1. electrical. heater comprising a dle formed of a plurality of radial vanes suitably secured together each of said vanes bemg provided with transverse perforations,

intervals along its edge, and a spirally wound and with notches or serrations at regular heating element supported in said serrations.

2. An electrical heater comprisinga spindle made up of a plurality of radially disposed vanes, angle irons to which said vanes are secured near their inner edge, said vanes.

having a plurality of transverse perforations to provide ventilating openings, and also being formed with serrations at regular intervals along. their outer edge, a spirally twisted heating coil wound around said spindle and lying in said serrations, and a forarninous housing surrounding said coil. 3. An electrical heater, comprising a spin- '-dle made up of a plurality of separately formed, radial vanes, angular members to'- which said vanes are secured around a common center so as to leave an opening therethrough, a heating element spirally WOllIld on said spindle, a housing surrounding said spindle, ends for said housing, and a bolt, passing through said opening and said-ends and serving to secure the latter in position,

electrical heater comprising a spindle formed of a plurality of blades or vanes.

suitabl secured together and extending radiflilly so; mounted that longitudinal spaces are formed between them, each of said vanes being provided with a plurality of transverse ventilating openings, and a heating element Wound spirally around said spindle so as to embrace said perforatedvanes. 1

l JOSEPH AROHIBALD M'EARS, JR. v CARLETON ELLIS.

.' Witnesses: 4

NATHANIEL L. FosTER, 4 HENRIETTA ,BERKWITZ.

oma common axis, said vanes being

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