US2041897A - Fan-heater - Google Patents

Description

May 26, 1936.

B. A. BENSON FAN HEATER Filed Aug. 3l, 1935 v3 Sheets-Sheet l May 26? 1936, E, BENSQN v2,041,897v

FAN HEATER Filed Aug. El, 1955 3 Sheets-5h69?. 3

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Patented May 26, 1936 narran stares;

rAreNr carica FAN-acerca Bernhart A. Benson, Chicago, lll., assigner to Chicago Electric Manufacturing Company,

Chicago, Ill., a corporation of Illinois .Application August 31, 1935, sei-iai No. sasso 16 Claims. (Cl. 2219-39) My invention relates to an electric fan and heater combination, particularly suitable for use in bath rooms, for warming air and projecting the warmed air in a diverging blast of a relatively small cone angle.

Generally speaking, the objects of my invention are those of providing a relatively inexpensive, easily manufactured and efficient combination of an electric fan with a glow heater of the type in which rays o heat are forwardly deflected and vreflected bythe forward surface of the reector' so that a visualizing of the apparently glowing reflector will have the psychological eiect of enhancing the warming action of the warmed and forwardly projected air.

Moreover, my invention aims to provide a heater-fan in whicha minor portion of the propelled air, adjacent .to the axis of the heating unit, will be warmed to a less extent and propelled less forcibly than the surrounding part of the air; and in which thevarious parts are so arranged and proportioned that the said axial part of the propelled air and the surrounding'warmed air will intermingle into a stream of air in which the central Iportion is substantially as warm as the air further from the axis of the said stream.

So also, my invention aims to provide an elllcient fan heater which will afford the needed warming effect at a considerable distance from the heater and over an area of considerable diameter.

In addition, my invention aims to provide a fan heater of the above characteristics, in which all parts can readily be within a single casing and A adequately guarded against having a child reach the hot heating element with its-fingers, in which all of the cooperating parts can be assembled as a unit on the front of the casing.' and in vwhich the casing will not become unduly heated.

Illustrative of my invention,

Fig. l is a front elevation of a fan heater, with the major portion of the frontal wire vguard broken away.

Fig. 2 is a central, vertical and longitudinal section taken along the line 2-"2 of Fig. l, with the electric heating unit, fan, motor and switch shown in elevation,

Fig. 3 is a horizontal section taken along the line 3-3 of Fig. l or Fig.- 2, with some portions 5 shown in elevation.

Fig. 4 is an enlarged and fragmentary iront elevation of the central portion of the reflector and parts adjacent thereto.

Fig. 5 is a perspective View of the stamping l0 which supports the heating unit from. the reflector.

Fig. 6 is a reduced rear elevation of the fan heater.

Fig. 7 is a central and vertical section taken l5 along the line S-ll of Fig. l through the reflector and the heating unit, with full lines showing the reilection of radiated heat from the reector and with dotted lines showing how the tube of air propelled past exterior of the heating unit increases forwardly in thickness.

Fig. 8 is a diagram showing the eiective distribution of the warmed air when my fan heater is in' operation and the relative velocity ci different portions of the warmed forwardly propelled air.

Fig. 9 is a reduced vertical section allied to Fig. 2, showing a modied embodiment in which a simple pedestal is substituted for the casing.

In Figs. 1 to 3, my fan heater includes a casing 30 having its front C provided with a circular opening corresponding in diameter to the outside cliameter of the annular and forwardly concaved reflector R which extends behind the said casing front, and which recctor has a peripheral ange fastened to that front by bolts l which also fasten the peripheral portion of a wire guard G to the casing front.

Supported forwardly o f the vertical plane of the aperture A in the reflector is an electric heat- 40 ing unit comprising a forwardly flaring tubular insulating body H having an exterior spiral groove G for definitely positioning a coil of highresistance'wire W wound on the said insulating body.` This body or wire carrier is desirably supported from the reector by a stamping (formed as in Fig. 5) which includes a dat ring I bolted to lugs L on the said wire carrier and two arms a fastened respectively to diametrically opposite portions of the reilector R, and preferably by the 5 same bolts Tb which fasten the motor-supporting brackets B to the reector.

Moreover, the tubular body or wire carrier B of the heating unit is considerably smaller inv diameter than the aperture A of the reector, and

the bracket arms a of the said stamping are preferably shaped so as to dispose the rear end of the said wire carrier forwardly of theplane of the said aperture, as shown in Figs. 4 and 7. 'Ihus arranged, the recited assembly ai'fords an annular air outlet between the aperture of the reflector and the rear end of the wire carrier of the heating unit, and leaves the bore of this wire carrier open so that air can flow through it also from the interior of the casing.

Disposed within the casing C behind the reector R, and supported by two brackets B each of which is 'fastened to the reflector (desirably by the same bolts b which secure the heatingunit-supporting bracket arms a to the reector) is an electric motor. generallyl designated as M, having its shaft S coaxial with the reector. Fastened to the forward portion of the motor shaft, and freely spaced rearwardly from the plane of the reflector aperture A, is a fan F which has each blade thereof presenting its major portion behind the said annular air outlet between the reflector aperture and the rear end of the wire-carrying body B of the heating unit, the fan also having an imperforate portion F' connecting the inner ends of its blades.

I n practice, I desirably also employ one of the motor-supporting brackets B, as shown in Fig. 2, for supporting the circuit wires w which lead to the motor, which desirably is in series with the heating wire W, the current supply for both being controlled by a switch 2 presenting its handle I0 in front of the casing.

When this switch is closed, the operatii of the fan blows air forcibly through the said annular space between the bore the reflector aperture and the exterior of the rear end of the body B of the heating unit; but, since the generally imperforate central portion F' of the fan has an area almost equalling that of the rear end of the bore of the body B of the heating unit, air will move quite `slowly through that bore, thereby subjecting this part of the air to heat radiation from the bore of the heating unit for amuch longer period of time than the air which is forcibly propelled over the exterior of the said unit.

When arranged as heretofore described, namely with the reflector, motor. heating unit and control `switch all supported by the casing front C, my

fan-heater could be used without completing the casing, by merely providing means for supporting this sheet metal front in an upright position, as shown in Fig. 9. However, I preferably provide a complete casing (as in Figs. 2 and 3) both as a housing for the fan motor assembly and the switch, and for enabling me to control the volum and the direction of the entering air.

For this purpose, the drawings show the casing as` including an upright back C' freely spaced rearwardly from the motor M, this casing back being imperforate except for a plurality of air ports P which preferably are uniformly distributed overan annular area coaxial with the fan shaft S, the renector aperture A and the body B of the heating unit. 'I'his annular area preferably has its inner radius (r' in Fig. 3) larger than the exterior of any part of the motor, and desir.

wire-carrying body H which also becomes hot, will be redirected by the reflector, as shown partly by full lines 8 and partly by dotted lines I' in Fig. 7, so that the reflector would concentrate the heat within a tube area not m'uch greater than g the outside diameter of the reilector, (if the fan was not running).

Consequently, a user standing a few feet from a reector of say 10 inches diameter would have a warming effect concentrated over an area not l0 much more than a foot in diameter.

However, when the fan of my appliance is running, most of the air drawn towards it into the casing, as for example along lines such as d in Fig. 3, will be propelled forwards nearly parl5 allel tothe axis of the fan through the annular space i3 between the heater body H and the bore of the reector, a small portion of which air directly engages the heating wire while other parts of it brush the hot exterior of the heater body. Consequently. the major part of the air will be propelled as a tubular stream of air, which stream increases forwardly in thickness and exterior diameter as shown by the dotted lines l in Fig. '7.

Still another and relatively small part of the 25 indrawn air is propelled much more slowly by the radially inner portions of the fan blades. which, as shown in Fig. 1, present only small areas behind the bore of the said wire carrier. This air portion issues as a quite slowly moving cur- 30 rent of air of circular section and gradually merges into the bore of the said tubular stream of more forcibly propelled air to form a conical air stream which increases in diameter as it moves forwardly. Consequently, with a suitable pro- 35 portioning of the parts of my fan-heater, I can readily produce an vadequate warming effect of considerable area at a distance of three or four feet from my appliance, instead of having this eii'ect uxidesirably concentrated. 40

Since my construction conveniently allows the reilector to support the heating unit and the electric fan, these three major parts could be similarly assembled and used without the illustrated casing, as shown for example in Fig. 9, by 45 supporting the reflector on a pedestal I. Bowever, since this will allow the air to be drawn towards the fan from a wide area farther from thefanaxisthanthedottedlineslinll'ig.2,1 have found the resulting effect (with exactly the 50 same reflector, heating unit and electric fan) to be much less advantageous than it is when I also provide a casing which admits air only through a limited annular area in the back of the casing, as heretofore described. 55

Ihatistosay,theairw'illthenmoveatso high avelocity through the bore of the heating unit that the central part of the blast of air will not be materially heated, and the relatively trivial heating of the inner portion of the pro- C9 jected air will contrast uncomfortably with the warming effect of air farther from the axis of the said air blast. Moreover, the suction of the propelled air then. will also move entirely unheated air forwardly past the peripheryof the C5 reflector, thereby increasing the uncomfortableness of the result on any one standing in front of the reflector. lbr these reasons I preferably provide a casing having vs. limited air-port area for admitting air and presenting this area in an annular formation behind the fan.

For example, I have found my fan het'er adequate at a distance of four feet from the user for spreading adequate warmth over an area fully three feet in diameter, and with a fairly uniform air velocity in the annular outer portion of this area, as indicated by the velocity lines V, V and W in Fig. 8.

I have also found that while the velocity oi the warmed air is considerably less in a relatively small central portion of this area, the warming efiect of this central portion of the stream of heated air on skin exposed toit may be fully as great as the surrounding portion of the air, whichl assume to be because the air closest to the asis of the stream moved so slowly through the bore of the hot Wire carrier as to have ample time for absorbing heat from the latter. Y

When my ian-heater is in operation, the movement of air through the casing keeps the latter from overheating, so that it can freely be vtouched even vby a child, thus making it safe for household use. Moreover, when the heating wire is of the desirable resistance which causes it to glow when hot,A this glow is reflected by the reflector,l and all the more impressively so when the latterv is paneled as shown in the drawings. Consequently, the refiectionoi this glow also has a psychological eiect-after the manner of a hearth ire-oi stimulating the feeling of warmth in a user who faces the reector.

By mounting the entire operating parts on the casing front, l simplify and cheapen the assembly; and by placing my heating coil on a tubular carrier which has many times greater exterior as well as interior heating-radiating surface and moving air over these surfaces at the above described decidedly different velocities, I obtain an approximately uniform distribution, over a considerable cone angle, which lhave been unable to obtain with fan heaters oi heretofore proposed constructions.

However, the proportioning of numerous parts of my fan-heater, as Well as the shape of the reilector, may be considerably varied, and with a -heating unit of higher wattage the cone angle of the projected stream of warm air may be increased (from the approximate 30 degree angle of Fig. 8) to about 40 degrees. So also, it will be obvious that other changes may be made without.

departing either from the spirit of my invention or from the appended claims.

I claim as my invention:

1. A ian heater comprising an annular and forwardly concaved reflector having a substantially unobstructed bore; an electric heating unit substantially housedI by the reflector, the said unit comprising a tubular body-coaxial with the reilector and of smaller exterior diameter than the bore of the reector, the said body having its rear end generally freely spaced from the said reflector bore, and a high resistance wire supported on the periphery of the said body; and an electrician disposed behind coaxial with the reflector for blowing air through the bore of the reflector and through the bore of the heating unit; the fan including a bladed member freely spaced rearwardly from both the reflector and the said body and rotating about the axis of the reector, and presenting the major part of the area of each of its blades behind the space between the bore of the reector and the rear end of the said tubular body.

2. A ian heater as per claim 1, in which the bladed member of the fan also presents blade portions directly'behind the bore of the tubular body,

the area of which blade portions is a minor fraction of the area of the blade parts disposed behind the said space.

3.A fan heater as 'per claim 1, in which the said body has a rearwardly tapering frustroconical peripheral surface and in which the heating wire is a coil of high-resistance wire wound spirally and peripherally around the said body, the said body having its rear end spaced forwardly from the plane oi the bore of the reflector by a distance less than the radial spacing of the periphery vof the said rear end from the said reector bore.

4. A fan heater as per claim 1, and in which the electric fan includesa motor and a fan-blade member rotated by the motor; the fan heater including an upright casing having its front provided with an aperture spanned by the reiiector, the said casing housing the entire electric fan, and the back of the casing having air-admitting provisions distributed over an annular area coaxial with the reflector and fan, the bore of the said area being approximately equal to the bore ofthe annular reflector.

5. A fan heater as per claim l, including an upright casing having its front provided with an aperture spanned by the reflector, 4the said casing housing the entire electric fan, and the back of the casing having air-admitting provisions distributed over an annular area coaxial with the reflector and fari; the bore of the said area being approximately equal to the bore of the annular reii ztor, and the total aroaof the said air-admitting provisions being not less than the area of the annular space betweenthe bore of the re- :dector and the rear end ott the body of the electric heating unit.

6. A fan heater as per claim l, including an uprightcasing having its iront provided with an aperture spanned by the reflector, the saidA casing housing the entire electric ian, and the back of the casing having air-admitting provisions distributed over an annular area coaxial with the reflector andan; the electric fan and the said tubular body being both supported by the saidI iront of the casing, and the fan being freely spaced forwardly from the back of the casing.

7. A ian heater as per claim 1, including an upright casing member having an aperture spanned by the said reflector, the reector being supported by the said 'casing member and the electric fan being supported by the reflector.

8. A fan heater comprising an annular and forwardly concaved reector having a substantially unobstructed bore; an electric heating unit comprising a tubular body of insulating material coaxial with and substantially housed by the reflector, the said body having its rear end of smaller exterior diameter than the bore of the annular reflector so as to leave an annular space between the said rear end and bore; an electric heating member supported on the periphery of the said tubular body; and means behind the said body for simultaneously blowing air forwardly through the said annular space and also propelling a relatively much smaller volume of air, at a minor fraction of the velocity of the aforesaid air forwardly through the bore of the said tubular body.

9. A fan heater as per claim 8, in which the v tubular body is a rearwardly tapcring-frusto-conical tube, the rear end of the bore of the said tube being larger in diameter than the Width of the said annular space.

10. A fan heater as per claim 8, including a owing having a frontal aperture spanned by the said reflector and having a. back provided with air ports disposed radially 4outward of a circular and imperforatecasing back area coaxial with the renector, the diameter of the said area being not materially less than that of the bore of the annular reflector.

11. A fan heater as per claim 8, in which the parts are proportioned so that the air blown propeiled through the bore of the tubular body is warmed to approximately the same temperature, by heat radiation from the said body, as'the temperature to which the air blown through the said annular space is warmed conJointly by contact with the heating member, by radiation from the said body and through the reflection of radiated heat by the reflector.

12. A fan heater as per claim 1, in which the said bladed member has a central and effectively lmperforate portion of a diameter at least equal to the radius of the bore of the rear end of the said tubular body.

13. A fan heater comprising a tubular and axially horizontal electric heating unit; means for propelling a tube of air at considerable velocity coaxial with and contiguous to the exterior of the said unit, and simultaneously therewith causing air to ilow in the same direction through the bore of the said unit at a small fraction of the aforesaid velocity; and means for reilecting heat radiated by the heating unit indirections radially outward of that unit, the heat-reflecting means being arranged for reflecting the said heat in a tubular formation coaxial with the said unit and in the aforesaid general direction.

14. A fan heater comprising an axially horizontal tubular `wire carrier, a coil of heating wire supported on the periphery of the wire carrier, and

i an electric fan disposed behind and near the said wire carrier and including a blade member coaxial with the wire carrier and having the major portion of each blade farther from the axis of the wire carrier than the radius oi' the rear end of the said carrier; an annular reflector coaxial with the said carrier and having an unobstructed bore of a diameter intermediate that of the peripheral reach of the blades and of the rear end of the wire carrier; and means for supplying current to 5 the electric ian. and to the heating wire at such a rate as to cause the latter to glow, the reflector being formed for forwardly reflecting the said glow and the fan being arranged for blowing air forwardly.

15. A Ian heater comprising'a forwardly flaring tube of insulating material disposed with its axis horizontal; a' coil of high resistance wire wound spirally on the periphery of the said tube; a Iorwardly concaved annular reflector coaxial with and substantially housing the said tube; the reilector having a bore diameter considerable larger in diameter than the rear end of the said tube and having its bore portion in a plane spaced rearwardly from the said rear tube end; and an electric fan disposed behind the reflector and includinga blade member coaxial with the said reilector and tube; the blade member being formed so that by far the greater part of the air propelled by the blades will flow at considerable velocity through the annular space between the rear of the said tube and the bore of the reflector at a much higher velocity than that at which the remaining portion of the air is propelled through the bore of said tube.

16. A fan heater as per claim 8, in which the said means comprise a rotating fan coaxial with the reflector and spaced rearwardly from the plane of the aperture in the reflector by a distance less than the radial spacing of the rear end 35 'of the said body from the bore of the said aperture.

BERNHART A. BENSON.

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