US2512061A - Electric radiating heater - Google Patents

Description

June 20, 1950 A .j` HUCK i 2,512,061

ELECTRIC RADIATING HEATER Filed March 13, 1947 I V EN TOR.

Patented June 20, 1950 ELECTRIC RADIATING HEATER Alfred J. Huck, St. Louis, Mo., assigner to Knapp- Monarch Company, St. Louis, Mo., a corporation of Delaware Application March 13, 1947, Serial No. 734,395

My present invention relates to a heater which has a normally exposed heating element such as electric resistance wire wound on a core and located Within a reflector and to a guard for the heating element, the invention being an improvement on my co-pending application Serial No. 567,947, filed December 13, 1944, now Patent 2,467,479, issued April 19, 1949.

One of the objects of the present invention is to provide a guard in the form of a shield in front of the heating element which prevents dresses, sashes or the like, which might get through the usual wire protective cage at the front of an electric type heater, from coming into Contact with the resistance wire of the heater, the shield being protected from the heat of the heating element by a second shield interposed between the heating element and the first shield.

Another object is to provide a reflector or 4bowl type heater with means to positively roll it over on its back when it is accidentally tipped forwardly so that the reflector then points away from the rug or iloor instead of permitting the concentrated heat from the heating element to be directed toward the floor.

A further object is to provide the foregoing improvements of such character that they do not interfere with the heat radiated from the heater, and can be `much less expensively applied thereto than a ne screen outside the guard wires which, though a solution, does not produce a good appearing and saleable article.

With these and other objects in view, my invention consists in the construction, arrangement and combination of the various parts of my device whereby the objects contemplated are attained as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawings, in which:

Fig. 1 is a perspective View of a reflector type heater with my safety guard arrangement applied thereto;

Fig. 2 is a sectional view through the center of the heater showing the heating element guard or shield in place and a second or intermediate shield between it and the heating element;

Fig. 3 is a front elevation of the intermediate shield looking in a righthand direction at it in Fig. 2;

Fig. 4' is a view from the .top showing the 5 Claims. (Cl. 21S- 34) heater tipped forwardly and contacting a floor surface to illustrate an unstable position from which the heater will roll over on its back to avoid directing heat rays toward such surface.

Fig. 5 is a diagrammatic view showing different vforms of support for the shields, the shields being supported from the reflector of the heater.

Fig. 6 is a similar diagrammatic View of another modified form of support in which the shields are supported from a wire cage guard of the heater, and

Fig. 7 is a diagrammatic view showing relative radii and diameters that I have found most suitable for a guard of the character disclosed.

On the accompanying drawing I have used the reference numeral I IJ to indicate a base and I2 a reilector of a reflector type heater. The reflector I2 has the usual guard formed of wires I4 and a connecting disk Il at the center. Within the reflector I2 a heating element HE is provided. The heating element HE may be in the form of a ceramic core t6 on which is wound a resistance Wire I8, the heating element being supported by a pair of bolts 20 which also serve as terminal connectors for the resistance wire. These terminals may be connected with an electric service cord 22 extending into a housing 24 within which the electrical connections are made.

As shown in my co-pending application, a guard 25 is provided in the form of a shield which may or may not be cupped as disclosed and which may be supported on the heating element HE by means of a screw 28 threaded into a cross bar 30. The cross bar 3U has its ends received in opposite openings 32 of the core I6.

I found that when the shield 26 was supported directly against the outer or left end of the core I6 in Fig. 2 the intense heat from the heating element discolored it. The shield is preferably plated with chromium or the like for the sake of appearance and such discoloration is therefore objectionable. I have accordingly provided an intermediate shield 34 interposed between the core I6 and the shield 26 and spaced from both of them as by inturned ears 36 and outturned ears 38. The shield 34 may also be cupped as illustrated. Three of the ears 36 and three of the ears 4EIB may be provided as illustrated in Fig. 3.

- v'lhe intermediate shield 34 may become quite hot without the outer shield 26 being discolored and the shield 34 thereby shields the shield 26 from the direct rays of heat from the resistance wire I8 and also from reflected rays of heat. There is also some thermal circulation of air upwardly between the shields 34 and 26 to carry away excessive heat and thus prevent discoloration. This also prevents the shield 26 from attaining as high a temperature as it otherwise would, as the shield 34 cuts down heat transfer to the shield 26. The guard characteristics of the shield 26 are therebyenhanced.

The wire guard I4 has one wire indicated at I5 which it will be noted is bulged farther away from the reflector I2 than the others. the lowermost center wire of the guard and4 has this different shape for a specific reason, as will' hereinafter appear.

The base IU has a pointed projection indicated' at 4D and located at the front end of the base. The wire I5 and the projection 40 cooperate with each other as shown in Fig. 4 to provide a two point support for the heater if it is accidentally tipped forward onto the oor surface indicated at 42. If the heater is sidewise from the position shown in Fig. 4 when it` strikesV the floor, then it will automatically rollover on its back due to the curvature of the guard wires I4 and the curvature and weight distribution of the base I0, and the curvature of the reflectorv I2. To prevent it' from staying in theV position of Fig; 4 however the wire I5 and the projection 40 serve asl pivots so that the" heater is in an unstable position if it tips straight forward and must then of necessity tip out of that position so that it will roll over on its back. This prevents the radiated and reflected heat rays from the: heater being directed toward the surface: 42, butA in'- stead they will beA directed' upwardly and there is no danger then that the floor will belburned` by the heater.

As shown inl my co-pending4 application, the shield 26 need not necessarily be` a cupped sheet metal guard as it may take other shapes and be formed Vof other materials. The interme'diate shield 34 may also be formed of' suitable materials other than metal, if desired, and both shields may be supported' inv any suitable manner' rather than on the heating element itself.. The-disclosed arrangement provides anV eilicient portable radiant heater from which theimajority ofthe radiated heat is emitted'outside the shield.y Tip-over objections are met with asmaller'size devicelfor the wattage used. This is an obvious economy of manufacture.

While I haveshown in Fig. 2 a means of supporting the shields 26 and'. 34 from the heating element HE, they can be supported by other methodssuchA as shown in Figs. 5i and 6. In Fig; 5 a plurality of struts 28a may extend from the reflector, past the shield 34 to the shield 26 and be suitably secured to both shields. as by spot welding or the like. Thestruts 2'8` may be formed of sheetV metal and in anyv desired numv` ber, preferably three, the outer ends being'spot welded or otherwise suitably secured to` thev reector; y

In Fig. 6I show a strut 28o in the form of' a' post (preferably tubular) extending from a central disc I'I that serves as a name plate'on the wire cage I4 to the shield 26 forsupportingit'; A second strut 28d forms an extension of the strut 28e for supporting theY shield 34v from the shield 26. Thus it is obvious that the shields 26 and-34 needf not'necessarily` be supportiaibyA the heating This ilsrv 4 element itself in order to serve as a guard against articles contacting the heating element.

I have found that certain constants produce maximum eciency in a guard of the kind herein disclosed. Referring to Figure 7, several dimensions are shown and these I find are more or less critical and bear approximately the following relations to each other:

These seem to be the critical dimensions although other dimensions such as the spacing of the heating element HE from the reflector I2 and the guards 26 and 34 from the heating element are somewhat critical and approximately of the proportions illustrated in Figure '1.

TheV arrangement including the intermediate shield 34 provides a practical construction whereinl the intermediate shield prevents discoloration to the outer shield 2S which is preferably chrome plated for appearance sake. The shape of' the inner shield 34 is a compromise between that of the outer shield and the forward end of the heating element HE. The arrangement' makes pose sible a relatively small heater and a safety shield applied thereto with the heating element rated atSOO'watts or more. I nd that not much variation from the above listed proportions can be tolerated for a practical design.

Some changes may be made' in the construction and arrangement of the parts of my device without departing from the real spirit and purpose of my invention, and; it is my intention to cover by my'claims such modied forms of structure or use of mechanical equivalents asimay be reasonably included within their scope'.

I claimY as my invention:

1. In an electric heater structure, a heater, a reflector therefor, a safety guard comprising a shield element adjacent and` spaced from the outer end of the heater in aA position opposite said Vreflector to prevent inflammable articles entering said reflector from engaging said heater, and av second shield element interposed between said rstl shield element andY said heater and thereby also opposite said reflector', said second shield: being spaced from both said first shield element' and' said heater to reduce the heat ra-l diatedv and reflected to the rst shield element.

2. In an electric heater device, a heater, a reector therefor, a' safety guardV comprising a cupped guard shield to guard articles entering the reflector from contact with said heater, saidV guard shield being supportedv in spaced relation to the forward end of said heater, and an intermediate' cupped shield to reduce heat transmission to the first guard' shield, said intermediate shield being formed of sheet metal and' having fingers extending rearwardly to engage said heater and other fingers extending forwardly to engage said first guard shield and space both shields and the heater'in relation to each other.

3. A heater structure having a heaterV and. areflector therefor, anda safety' guard for said heater comprising a cupped shield in front' of said heater and extending backv over its outer end, and an intermediate partition to reduceheat' transmission to said shield, saidV partition being cupped and also extending back over the outer end of said heater and being spaced from both" the heater' and the-shield to permit"tln'arxnal"cir-y culation in both spaces said partition terminating within said shield.

4. In an electric heater structure, a heater, a reflector therefor, a cupped shield to guard articles entering the reflector from contact with said heater, said shield being supported in spaced relation to the forward end of said heater, and an intermediate shield to reduce heat transmission to the rst shield, the dimensions of said heater, said reflector and said rst shield being substantially as follows in relation to the radius (R) of curvature of the reflector:

Diameter of reflector 1.5R,

Diameter of shield .65R Diameter of heating element .24R Radius of curvature of shield .35B

5. In an electric heater structure, having 'a heater, a reflector therefor, a cupped guard shield to guard articles entering the reflector from contact with said heater, said guard shield being supported in spaced relation to the forward end of said heater, and an intermediate cupped 6 shield to reduce heat transmission to the first guard shield, the diameter of said reliector being substantially 1.5R, the diameter of said guard shield being substantially .65R, the diameter of said heater being substantially .24R and the radius of curvature of said guard shield being substantially .35R wherein R is the radius of curvature of said reflector.

ALFRED J.HUCK.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,837,829 Noble Dec. 22, 1931 1,917,461 Rankin July 11, 1933 FOREIGN PATENTS Number Country Date 326,326 Great Britain Mar. 13, 1930 523,374 Great Britain July 12, 1940

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