US2675460A - Air heater - Google Patents

Description

pril 13, 1954 M. H. WINNER, JR 2,675,460

AIR HEATER Filed May 5, 1955 2 Sheets-Sheet l INVENToR.

Mae H. WMM/Ee, Je.

i BY

April 13, 1954 M. H. WINNER, JR

AIR HEATER 2 Sheets-Sheet 2 Filed May 5 1953 INVENTOR. MHRK h- //A/A/EE, Je.

Patented Apr. 13, 1954 UNITED STATES PATENT QFFICE AIR HEATER Mark H. Winner, Jr., New York, N. Y.

Application May 5, 1953, Serial No. 353,189

(Cl. 21S-39) 2 Claims. 1

This invention relates to heating devices, and more particularly has reference to an air heater of the type wherein air is circulated through the device by a blower means, and is electrically heated during its passage through said device.

Summarized briefly, the present invention includes an upstanding housing of generally ilat outer coniguration, arranged to occupy a minimum space. Formed within the housing is an air conduit, the opposite ends of which are communicated with the atmosphere exteriorly of the housing through inlet and outlet openings formed in the housing. The conduit, according to the present invention, is of spiral formation, the spiral being ofthe flat type and lying in a vertical plane. A centrifugal blower mounted in the housing at the inner end of the spiral is arranged to draw air inwardly through the inlet opening of the housing, and to force said air longitudinally of the conduit for discharge from the outlet opening. Within the conduit an elongated resistance element is mounted, said element being spiralled correspondingly to the conduit and extending substantially the full length of the conduit to warm air during the passage thereof between the inlet and outlet openings.

The extension of the air conduit through a flat, vertically disposed spiral desirably elongates the air passage, while at the same time conning the passage to a relatively small cubic area. the same time, the spiral formation of the heating element, with said element extending from end to end of the conduit, increases the eiciency with which the air is heated during passage thereof between the inlet and outlet openings of the heater.

The main object of the invention, accordingly, is to provide an air heater wherein the radiant heat of an electrical heating element will be utilized with maximum eiciency to warm air passing through a spirallng duct or conduit, thus to allow the space into which the warmed air is discharged to be evenly heated by convection, rather than by the relatively uneven heating resulting from heat radiation from a heating unit of comparable size.

Another object of importance is to provide, in a device of the type stated, a simplified construction that will facilitate the assembling of the parts. To this end, I propose to form the heating device with a housing the back of which will initially be open. Thereafter, a flat support plate is mounted in the back of the housing to close the same, and preassembled with said plate is a spirally extended conduit wall, said wall pro- All.

jecting forwardly from the plate, so as to engage against the inner surface of the front wall cf the housing. In this way, the housing, plate, and conduit wall cooperate to define the spiral duct. The centrifugal blower, the motor associated therewith, and the heating element are all mounted on the support plate, so as to be preassembled with said support plate along with the conduit wall, prior to insertion of the plate in the open back of the housing.

Another object of importance is to provide a heater of the type stated which will be so designed as to permit the same to be used not only as a room or space heater. but also, with slight modifications, as a hair dryer, drying means to be associated with a washing means, etc.

Other objects will appear from the following description, the claims appended thereto, and from the annexed drawings, in which like reference characters designate like parts through the several views, and wherein:

Figure 1 is a perspective view of a heating device formed in accordance with the present invention;

Figure 2 is an enlarged sectional view taken substantially on line 2-2 of Figure 1;

Figure 3 is a transverse sectional view taken substantially on line 3-3 of Figure 2;

Figure 4 is a diagrammatic view showing the electrical circuit embodied in the invention; and

Figure 5 is an enlarged, detail sectional View taken substantially on line 5--5 of Figure 2.

Referring to the drawings in detail, the reference numeral l0 has been applied generally to a housing, which housing can be formed from sheet metal material or the like. The housing, in the illustrated embodiment of the invention, wherein a room heater has been illustrated, includes a flat, horizontally disposed, rectangular bottom wall I2 integral or otherwise made rigid at its opposite ends with relatively short, depending legs I4. Projecting upwardly from the opposite ends of the bottom Wall I2 are side walls I6, said side walls being vertically disposed and being in tegral with the opposite side edges of a generally square, vertically disposed front wall I8.

The back of the housing l0 is formed open, but at its top, the housing has a horizontally disposed top wall 20.

Preferably, a handle 22 is secured to the top wall 2t, to facilitate movement of the heater from place to place.

Formed centrally in the front wall I8 is a circular air inlet opening 24, and mounted in said opening is a register 26 of barred or open mesh formation.

In the top wall 2l), intermediate opposite ends of the top wall, a relatively elongated rectangular opening 28 is formed, said opening comprising an air outlet opening.

Mountable within the housing I is a conduit and heating assembly 30, which assembly includes a flat support plate 32. The support plate 32 is of rectangular outer configuration, the periphery of said plate fitting snugly within the open back of the housing, thus to cause the plate to close the housing at its back when the assembly 30 is mounted within the housing.

The plate 32, at its center, has an opening 34 through which extends the horizontally disposed shaft of an electric motor 36 mounted in back of the plate 32 upon a bracket 38 of inverted U shape Iixedly secured to the back surface of the plate 32.

Secured to the forwardly projected portion of the motor shaft is a centrifugal blower 40, said blower 40 being disposed concentrically with the inlet opening 24, and being so arranged as to draw air inwardly through said inlet opening, when the blower is in operation.

Prior to mounting of the plate 32 within the housing, I assemble with said plate an elongated strip of sheet metal or the like, said strip being designated by the reference numeral 42 and having one edge fixedly engaged in a spirally extending groove 44 formed in the plate 32.;

The strip 42, when mounted in said groove, denes a conduit wall, said strip projecting forwardly from the plate 32 into engagement with the front wall I 8 of the housing.

At one end, the strip 42 is provided with an ear 43, secured to the plate 32 by means of a screw 43 or an equivalent fastening element. Other ears U, 52, 54, 5B, 58 are spaced longitudinally of the strip 42, and are similarly secured to the plate 32, thus to dispose the strip in a spiral path. A short strip portion 60 is mounted upon the plate 32, adjacent the top edge of said plate, said strip portion 68 being secured to the plate by means of an ear 62, and being so formed as to cooperate with the outer end of the strip or conduit wall 42 in dening a widened outlet for an air duct defined by the strip, plate 32, and front wall i8.

It will be seen that on insertion of the plate 32 within the housing, there is provided a relatively elongated air conduit, the inner end of which is in communication with the inlet opening 24, and the outlet end of which is in communication with the outlet opening 28. In this connection, the outer end of strip 42 and the outer end of strip portion te are secured to the plate 32 at opposite ends of the opening 23, and spaced longitudinally of opening 28 are transversely disposed louvers 34, said louvers 64 being each provided, at one end, with an ear whereby the louvers are iixedly secured to and project forwardly from the plate 32.

Within the air conduit I mount an elongated electrical resistance unit 66, said unit 65 being disposed spirally in correspondence with the spiral formation of the conduit, and extending substantially from end to end of said conduit as best shown in Figure 2. The unit 66 is disposed medially between the opposite side walls of the conduit, and is also spaced outwardly from the inner wall of the conduit defined by the plate 32.

To mount the unit 66 in this position, I provide support posts 68, spaced longitudinally of the heating unit or element, said posts 68 being of insulating material and being formed. as shown in Figure 3, with openings in their outer ends through which the unit extends. The inner ends of the posts 68 are reduced and threaded, and extend through openings formed in the plate 32, nuts being threaded upon the reduced portions of said posts 68 to mount the posts upon the support plate.

At one end, the resistance element 66 is provided with a terminal, which has been shown to its best advantage in Figure 5. As will be noted. a support post 10 of insulating material has a reduced, threaded inner end portion or base 12 extending through a smooth walled opening formed in the plate 32, a nut 14 being threaded upon said base to secure the post 10 in position upon the support plate.

Formed in the post 10 is an axial bore. and extending through said bore is a conductive terminal screw 16, to one end of which is connected the adjacent end of the resistance element 66. To the other end of the terminal screw there is connected a lead 18.

The other end of the resistance element 66 is secured to a similar terminal 16, and extending from the last-named terminal is a second lead 18.

Referring now to Figure 4, wherein the electrical circuit embodied in the invention has been shown, it will be noted that the motor 36 is connected, through the medium of the leads 18, to the element G5, in parallel with said element. In this connection, there is extended from one of the resistance element terminals a lead 80, said lead 8U extending from one side of the house circuit. A lead 82 extends from the other resistance element terminal, to the other side of the house circuit, the leads 80, 82 being encased in the sheath of an electric cord 83 having the usual lug, whereby the device can be connected to an ordinary convenience outlet.

A switch 84, adapted to be operated either manually or thermostatically, as desired, is in series with the motor and resistance element, said switch being mounted in the lead 82 in the illustrated example of the invention.

Preferably, the device is designed to minimize heat losses through radiation, and to this end, the inner surface of the front wall I8 is covered by sheet insulation 86, which insulation may in turn be aided, in resisting heat losses through radiation, by aluminum paint or the like.

Similarly, the plate 32 is provided, over its full area, with sheet insulation 88, and again, aluminum paint may be used to further reduce radiant heat losses.

After the assembly 30 has been mounted in place within the housing l0, a back cover plate is inserted in the back of the housing, said plate 98 being spaced rearwardly from the plate 32 as shown in Figure 3. Plate 9U has a center opening 82, the motor 36 projecting rearwardly through said center opening. In this way, the motor will be partly disposed exteriorly of the housing, thereby to facilitate cooling of the motor.

It will be noted that any suitable means can be employed to mount the assembly 30 and cover plate 30 in place, and as one example of such a means, I show connecting bolts 94, one bolt 94 being provided at each corner of the housing. The bolts 94 would extend through suitable openings formed in plates 32, 98, and may be threaded in sockets formed in the corner portions of the front wall i3.

In the illustrated example of the invention, there has been shown a space heater, which can be used to advantage at any desired location within an enclosure such as a room. It will be observed that when the device is in operation, the blower will draw air inwardly through the opening 2li, and will cause said air to travel through a spiral path, from the inner to the outer end of the conduit. At the outer end of the conduit, the air is diffused, passing through the outlet opening 28, thus to eiiciently warm the space surrounding the heater. It is important to note, in this regard, that radiant heat losses are cut down to a minimum, thus to cause the heater to warm the space by convection, rather than by radiation. Efhcient use is made of the heating element, by formation of the heating element as a spiral, extending in correspondence with the spiral duct formation and formed to a length generally approximating that of said duct.

Further, it is important to note that the heating element is so disposed as to be spaced outwardly from the several walls of the duct, the heating element extending longitudinally and centrallyT of the duct. In this way, the radiant heat emanating from the element will warm the duct walls, thus causing the air passing through the duct to become heated by impingement thereof upon the walls and element.

I believe it is sufficiently obvious as not to require special illustration that the device could be used not only as a room heater, but also as a hair dryer, dryer means for a clothes washing machine, etc. Some small modifications might, of course, be necessary in these instances, but the basic construction illustrated and described would, I believe, remain unchanged. When used as a hair dryer, the device could be iitted with an elongated attachment mountable upon the top wall 20, said attachment extending from the outlet opening 28 to a discharge head through which air can be directed against the hair of a user. When the device is to be used as a main or supplementary drying means associated with a clothes washer, the device could be mounted directly within the outer casing of the washer, with a duct extending from the outlet opening Zd to the interior of the washer, where it will Warm clothes during, for example, a spin-dry cycle.

Apart from the spiral design of the duct and heating element, the construction which I have devised has other advantages which are thought worthy of note. Among these is the construction wherein the assembly 3d can be manufactured as a separate unit, with all the parts thereof being pre-assembled prior to insertion of `said assembly within the housing Iii. Since the assembly 3B is secured in the housing only by the connecting bolts 94, removal of said bolts will permit the entire assembly 3e to be removed bodily, for performance of necessary maintenance, repair, or cleaning operations.

Further, it is to be noted that at the duct outlet, the duct widens substantially. The effect of this arrangement is to decrease blast and extreme temperatures at the outlet, and to provide, instead, an air distribution that is characterized by its evenness and the comfortable level of the air temperature.

It is believed apparent that the invention is not necessarily confined to the specific use or uses thereof described above, since it may be utilized for any purpose to which it may be suited. Nor is the invention to be necessarily limited to the specific construction illustrated and described, since such construction is only intended to be illustrative of the principles of operation and the means presently devised to carry out said principles, it being considered that the invention comprehends any minor change in construction that may be permitted within the scope of the appended claims.

What is claimed is:

1. An air heater comprising an upstanding housing generally hat in respect to the outer configuration thereof and having an open back; a ilat support plate mounted in the open back of said housing to close the same; a spiral conduit carried by said plate and lying in a vertical plane, the housing having an air inlet opening in one of its side Walls communicating with the inner end of said conduit and an air outlet opening in its top wall communicating with the outer end of said conduit; a centrifugal blower mounted in the inner end of the conduit and arranged to pull air inwardly through said inlet opening and force the same longitudinally of the conduit for discharge from the outlet opening; and a heating element spiralled correspondingly to the air conduit and extending longitudinally of the conduit substantially from end to end thereof, for warming said air during passage thereof through the conduit.

2. An air heater comprising an upstanding housing generally fiat in respect to the outer configuration thereof and formed with an open back, an outlet opening in its top wall, and an inlet opening disposed centrally in its front wall; a flat support plate removably mounted in the open back of the housing to close the same; a spira-liv formed conduit wall mounted upon said plate and projecting forwardly therefrom into engagement with the front wall of the housing, said front wall, plate, and conduit Wall cooperating to form, withi the housing, a spirally extending air conduit, said inlet opening communicating with the inner end 0f said conduit and said outlet opening communicating with the outer end of the conduit; a centrifugal blower mounted upon said plate at the inner end of the conduit and arranged to draw air inwardly through said inlet opening and force the same longitudinally of the conduit, for discharge of the air through the outlet opening; and a heating element mounted upon said mounting plate and extending spirally within the conduit substantially from end to end thereof, for warming said air during the passage thereof through the conduit.

References Cited in the file of this patent UNITED STATES IATENTS Number Name Date '745,507 De Mare Dec. 1, 1903 2,479,571 Hewitt Aug. 23, 1949

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