US2119161A - Electric heater - Google Patents

Description

May 3l, 1938. A. Q. HAY

ELECTRIC HEATER Filed Oct. 10, 1936 3 Sheets-Sheet l al/a7 May 31, 1938. HAY

ELECTRIC HEATER 3Sheets-Sheet 2 Filed Oct. 10, 1956 17 0. Ha y W N\ W MM 9 %\w M May 31, 1938. A Q HAY 2,119,161

ELECTRI C HEATER Filed Oct. 10, 1936 5 Sheets-Sheet 3 Patented May 31, 1938- UNITED STATES PATENT OFFICE 17 Claims.

This invention relates to heaters and particularly to electric heaters of that character where-- in air is sucked past or around an electrically energized heating element and into a chamber by asuction fan and discharged from the chamber into the room by said fan.

The general object of this invention is to pro vide a heater of this character which, by reason of its detailed structure, is particularly efie 1 and in which the air may be highly heated a relatively small heating element, thus making the heater particularly economical.

Another object is to provide a heater of this character which carries a detachable fan, this 1 fan being capable of being removed entirely from the heater and used merely as a tan.

A further object is to provide a structure of this character having a cylindrical body into which the air is drawn and heated and from -which the air is withdrawn by a suction fan and ejected into the room, the body being so mounted that it may be turned vertically into any one of a plurality of positions so as to discharge the heated air upward, downward, or horizontally.

A further object is to provide means whereby the temperature of the air ejected from the heater may be regulated so as to increase or reduce it.

A still further object is to provide a heater including an outer and an inner shell, the inner shell defining a central chamber, a heating element through and around which air must pass to enter the space between said shells, and a large number of radially disposed metallic ducts or tubes extending through the annular space be tween the shells and opening at one end upon the outer face of the outer shell and discharging air into. the central chamber.

Still another object is to provide means whereby the air entering the annular space between the shells may be caused to circulate around this space and eventually be discharged into the central chamber defined by the inner shell.

A still further object, in this connection, is to provide a suction fan which will withdraw air from the central chamber and discharge this air into the room, the suction of the fan acting to cause air to pass across the inner open ends of the radiating tubes or ducts, and thus cause the air to be drawn through these ducts. this air in turn being heated by the heated air in the annularspace between the shells.

Still another object is to provide a damper at the rear end of the shells whereby air may be admitted directly into the central chamber to temper the air which is discharged through said ducts or tubes, the damper being capable of regulation to either entirely out off this air enli-e rug from the rear end of the chamber or regulate it.

Other objects will appear in the course of the following description.

My invention is illustrated in the accompanying drawings wherein:

Figure l is a vertical sectional view of a heater constructed in accordance with my invention.

Figure 2 is a rear end elevation thereof.

Figure 3 is a side elevation of the heater fan detached from the heater and supported upon a base.

Figure 4 is a section on the line 4-4 of Figure 1.

Figure 5 is a plan view or": the heating element.

Referring to these drawings particularly to Figure i, ii! designates an outer cylindrical metallic shell and ii an inner shell which is concentric to the shell l6 spaced therefrom. to provide an annular air space 52. The inner shell at its rear end is outwardly flanged at 13 and at its forward end there is a forwardly and outwardly extending flange M. The rear end of the space i2 is closed by a web or wall l5 which has plurality of perforations ill at its upper end and the forward end of this space i2 is also closed by a wall l1.

Disposed forward of the forward ends of the outer and inner shells is a fan casing ill, the rear end of which has centrally and rearwardly in clined flange i9, this flange having ed engagement with the forward end of the outer shell I!) at 20. Disposed to surround the outer shell iii and spaced therefrom is grill work or guard 2i formed of longitudinally extending and circumferentially extending bars 2| and '22, this grill work having threaded attachment to the flange 23 of the outer shell ill at 25. This flange is screw threaded on the outer side at its end for this purpose and to allow cap 253 to be screwed thereto, said cap closing or partially closing the rear end of the heater.

It will be seen that the inner wall or shell ll defines a central cylindrical chamber 2! which discharges into the fan chamber, the rear end of this chamber 21 being spaced from the cap 26. This cap 26 is provided with a plurality of openings 28, as shown in Figure 2, and pivotally mounted upon this cap by the rivet 29 is a damper 30 having any suitable means whereby it may be turned to more or less disclose the openings 23. The cap 26, as shown in Figures 1 and 2, is provided with an arcuate slot 31 and a headed pin 32 extends through this slot and engages the damper 36, so that the damper may be shifted to regulate the amount of air passing through the openings 2&3 and either entirely close the rear end of the heater or fully open it, or partly open it to the entrance of outside air.

Extending through the space 2 and opening at their ends to the outside air through the outer shell I6 and opening, as illustrated in Figure 1, through the inner shell to the chamber 27, are a large number of relatively small metallic tubes 33. The openings of these tubes to the chamber 21 are illustrated in Figure 1 and are designated 3 There will be hundreds of these tubes and as the tubes will be of thin metal, the walls of the tubes will conduct heat very readily, thus any exterior air passing into these tubes and passing through the tubes into the central chamher will be highly heated by the heated air in the space l2.

The air in the space 52 is heated by an electrically energized heating element designated generally 35, and shown particularly in Figures 1 and 5. As illustrated, this heating element is circular in form and provided with a plurality of passages 36 extending through the heating element. The element itself is of metal and contains any desired or required number of heating coils 37, which are adapted to be electrically connected in circuit with a source of current.

While I have illustrated a specific form of heating element, I do not wish to be limited thereto as other forms of electrically energized heating elements might be used, provided there is means whereby the air which passes into the space i2 will be caused to pass through or around or into intimate contact with the heating element. The air heated by this element circulates around the space it, as shown by the arrows in Figure 1, and as it circulates, it comes into intimate contact with the tubes 33, so that the air in these tubes will be highly heated. The heated air circulates around this space I2 and then passes out through the openings 6 into the space between the cap 26 and the rear end of the central chamber 21, and then is drawn longitudinally through this central chamber by means of the suction fan in the casing 38. The air circulating through the chamber i2 is bafiled by the tubes 33 which are disposed in staggered relation to each other so that this heated air will, to a certain extent, be held in this annular chamber l2, and thus a large portion of its heat will be given olf to the tubes 33.

The chamber 56 at its rear end carries an annular partition 38 and defines an opening whose diameter is approximately the same as the internal diameter of the chamber 21. The forward end of the casing it carries an outwardly fiared flange 33 which is slightly concave on its inner face. Fitting this concave inner face of the flange as is the returned flange 43 of a funnelshaped member 4i, which constitutes the discharge mouth of the heater. This funnel 4i at its inner end has a flange 42 which is. exteriorly screw threaded for engagement with an interiorly screw threaded ring 43 having a, plurality of supports 44 which engage a supporting plate or ring 45. This carries a plurality of inwardly and rearwardly extending radial braces 46 which in turn support the fan motor 47. This motor has, of course, a, central shaft which carries upon it the radial fan blades 48. This fan is a three speed suction fan and acts to draw the air from the chamber 27 into the fan casing and eject the air out through the funnel-shaped mouth 4|. Electric current for the fan motor is supplied by the conductor 49.

As illustrated in Figure l, the rear end of the casing of the motor 41 carries a relatively thick plate 50 to which the braces 46 are connected and this plate has a central screw threaded bore Normally disposed within the fan casing |8 rearward of the motor are a plurality of supporting legs 52 which are convergent and are rigidly engaged with a base 53 having a central screw 54 engageable in the screw threaded bore 5|. Of course, when the parts are in the position shown in Figure 1, the legs 52 perform no function, but if it be desired to use the fan separately, the fan and its frame are removed from the interior of the casing l8 and disposed, as shown in Figure 3, with the screw 54 engaging in a screw threaded aperture in a lug 55 which projects rearward from the fan frame 45, as shown in Figures 1 and 3. Thus the fan may be used as a separate unit when desired, the conductor 49 being provided with the usual plug 56 whereby it may be electrically connected to any suitable source of current. The removal of the fan from within the casing is secured by removing the set screw 51 which permits the funnel-shaped member 4| to be removed along with the fan casing. This funnelshaped member may be left attached to the ring 43, if desired, or removed, if desired, when the fan is used simply as a fan.

For the purpose of supporting the heater and permitting it to be rocked into a plurality of positions, I provide an arcuate supporting bar 58 which at its ends is connected in any suitable manner to the guard 2| and to the flange 39. This arcuate bar 58 passes through a slot 60 in a base 6|, the slot 60 being, of course, arcuate to conform to the curvature of bar 58. This base 6| has a plurality of supporting legs 62 which conveniently are four in number and this base 6| is also provided with the upwardly and outwardly curved arms 63 which at their upper ends are pivotally connected by a pivot pin 64 to the guard 2|. It will thus be obvious that the body of the heater may be shifted upon the pivots 64 so as to incline the heater either upward or downward or to support the heater in a horizontal position or any intermediate position desired. The body of the heater is held in this adjusted position by means of the set screw 65 shown in Figure 4, which extends through the base and engages against the side wall of the bar 58.

Preferably, the arcuate bar 58 will be formed with a longitudinally extending recess 66 within which the conductors for the fan and for the heater will be disposed. This recess will be closed by a plate 6'! held to the bar by screws 68 or any other suitable means. At its rear end the bar 58 will have a socket element 69 adapted to receive a plug 1!] connected to a conducting cord 7| having therein, as usual, two conductors. Disposed within the recess 66 is a main conductor 72 which in turn is connected to a switch 13 in turn connected to a socket 74 carried upon the inner face of the plate 61 and with which a plug 15 engages, the plug being connected by a conductor 76 to the coils of the heating element 35. The switch 13 may be of any suitable or usual construction, but is one which may be shifted to secure a plurality of heating effects for the heating coils to secure a high heat, a low heat or a medium heat, as desired, and of course, be capable of cutting off the heat entirely. I have not illustrated this switch in detail as switches now on the market will be used or adapted for this purpose. The main conductor 12' extends forward through the recess 66 and is connected to a switch 11 in turn connected to a socket 18 with which the plug 56 engages, so that the fan may be turned on or off. A handle 19 is mounted upon the upper portion of the casing l8 whereby the heater as a whole may be picked up and carried from place to place. The operation of this heater will be obvious from what has gone before. Air passing into the interior of the annular space l2 will be heated by the heater 35 and as this air circulates around through the space l2, it will transmit its heat to the thin-walled tubes 33 and the air passing through these tubes will be discharged into the central chamber 21. The rotation of the fan will cause air to be drawn longitudinally through the chamber 21 and this air passing across the inner openings of the tubes 33 will draw the air out of these tubes and draw the air forward and discharge it at the forward end of the heater through the mouth 4|. The heated air Within the chamber I2 will pass around this chamber to the upper portion thereof and then be discharged out through the opening or openings l5 and then, as shown by the arrows, discharged longitudinally through the chamber 21. The space between the wall I! and the annular wall 38 will also act as a heating chamber retarding slightly the passage of air and this air will be heated by the heat transmitted to the end wall I! of the chamber E2. The wall l5 will also act to heat air which is entering through the openings 28 of the damper. It will be seen, therefore, that the air entering from outside will be very highly heated by its passage through the tubes 33 and around the space 12 and by contact with the walls of the heating chambers.

If it be desired that the heater shall discharge air at a relatively high temperature, the damper may be nearly closed or entirely closed, in which case fresh cool air will not enter through the rear end of the heater, but all the air which is drawn out by the fan must pass through the tubes 33 and thus become highly heated.

If, however, it be desired to temper this air and reduce the amount of heat, this can be readily accomplished by opening the damper and allowing a greater circulation of fresh cool air into the chamber 31. This reduction or increase of heat may also be secured by the proper manipulation of the switch 13 to increase or decrease the amount of current passing to the electrical heating element. Thus the heat discharged from the heater may be easily regulated so as to secure a low degree of heat, a medium degree of heat or a relatively high degree of heat. By adjusting the heater upon its base, the heat may be discharged downward against the floor, upward into the room, or horizontally.

If it be desired to cut off the heat and allow the heater to cool, this is readily accomplished by shutting off the fan and the supply of current to the heating element and then turning the heater so that the forward end points downwardly. The fan will no longer create a suction through the heater and as a consequence, if the damper 30 be opened fully, the heated air contained within the space 21 will pass upward through the damper openings into the room and thus the heater will become readily cooled. As before remarked, it is an easy matter to remove the fan from the interior of the fan casing and then detach the base 53 from the member 54 and apply this base to the lug 55 in the manner shown in Figure 3, so that the fan may be used by itself.

Attention is particularly called to the fact that in my structure, while the air entering through the openings in the heating element is positively circulated through and around the shell 12 by the suction of the fan, yet too rapid circulation of the air is impeded by the very numerous air tubes 33 and by the wall l5 which is provided with only a few perforations disposed in a restricted area remote from the electric heater. Thus the heated air in the annular space l2 gives off its heat not only to the tubes 33 but to the outer shell as well, and to the rear plate or cap 26. The fan casing also is heated by the passage of the hot air therethrough and gives off its heat by conduction through the wall of the fan casing. The motor may be heat insulated, if necessary.

By using an exhaust or suction fan at the forward end of the heater, the air will be carried through the heater more effectively than if a blower is used at the rear end of the heater, because there will be less resistance to the movement of the air and a better projection of the heated products into the room.

It is to be particularly understood that a very large number of tubes 33 will be used. In order that the drawings shall not be confused, I have illustrated relatively few of these tubes, but it is to be understood that I may use any number of these thin-walled radiating tubes 33, that the electric heating element may be of any desired size and secure any desired degree of heat, and that the detailed construction might be modified in many ways without departing from the spirit of the invention as defined in the appended claims.

What is claimed is:--

l. A heater of the character described, including an outer and an inner shell, the inner shell defining an approximately cylindrical, central chamber, tubes extending radially between said shells and opening at one end through the wall of the inner shell to the outer air and at the other end into the central chamber through the walls of said shells, means for heating the air in the space between the shells, a fan casing forming a continuation of the open end of the outer shell, and a suction fan mounted in said casing and drawing air axially through the central shell and through said tubes.

2. A heater of the character described, including an outer and an inner shell, the inner shell defining a central cylindrical chamber open at one end, tubes extending radially through the space between said shells and opening at one end to the outer air and at the other end into the central chamber, means for heating the air in the space between the shells, a fan casing forma continuation of the outer shell at the open end thereof, a suction fan mounted in said casing and drawing air through the central shell and through said tubes, and means for regulatably admitting air to the rear end of the central chamber.

3. A heater of the character described, including an outer shell and an inner shell defining between them an annular space closed at its opposite ends, the inner shell defining a central chamber, an electrically energized heating element carried by the outer shell and having openings through which air may pass into said annular space, a plurality of thin-walled metallic tubes radial to the axes of the shells extending through the annular space and opening at their ends to the exterior of the outer shells and into the interior of the inner shell, and. means for forcing air through the central chamber.

4. A heater of the character described, including an outer shell and an inner shell defining between them an annular space closed at its opposite ends, the inner shell defining a central chamber, an electrically energized heating element carried by the outer shell and having openings through which air may pass into said annular space, a plurality of thin-walled metallic tubes extending radially through and transverse- 1y of the annular space and opening at their ends to the exterior of the outer shells and into the interior of the inner shell, means for forcing air through the central chamber, a cap engaging the rear end of the outer shell and spaced rearward of the inner shell, the cap having air openings, a damper controlling the passage of air into said openings, and means for discharging air from the annular space into the rear end of the central chamber.

5. A heater of the character described, including an outer metallic shell and an inner metallic shell defining between them an annular space, forward and rear walls closing the ends of said space, an electric heating element carried by the outer shell and having apertures through which air may pass into said annular space, a plurality of tubes extending radially through and transversely of the annular space and opening at their ends to the outside air and into the central chamber, a cap having detachable engagement with the rear end of the outer shell and spaced from the rear wall extending between the outer shell and inner shell, said rear wall at a point remote from the heater having an apening discharging toward the cap, a fan casing forming a continuation of the outer shell, and a suction fan in said casing.

6. A heater of the character described, includ ing an outer metallic shell and an inner metallic shell defining between them an annular space, forward and rear walls closing the ends of said space, an electric heating element carried by the outer shell and having apertures through which air may pass into said annular space, a plurality of tubes extending radially through the annular space and opening at their ends to the outside air through the peripheral walls of the outer and inner shells and into the central chamber, a cap having detachable engagement with the rear end of the outer shell and spaced from the rear wall extending between the outer shell and inner shell, said rear wall at a point remote from the heater having an opening discharging toward the cap, a fan casing forming a continuation of the outer shell, and a suction fan in said casing, said casing being detachable from the outer shell.

'7. A heater of the character described, including an outer metallic shell and an inner metallic shelldefining between them an annular space, forward and rear walls closing the ends of said space, an electric heating element carried by the outer shell and having apertures through which air may pass into said annular space, a plurality of tubes extending radially through the annular space and opening at their ends to the outside air into the central chamber, a cap having detachable engagement with the rear end of the outer shell and spaced from the rear wall extending between the outer shell and inner shell, said rear wall at a point remote from the heater having an opening discharging toward the cap, a fan casing forming a continuation of the outer shell, a suction fan in said casing, said casing at its forward end having an outwardly and forwardly directed flange, and an outwardly flaring member detachably engaged with said flange and affording a support for the fan.

8. A heater of the character described, including outer and inner metallic shells spaced from each other, a multiplicity of radially disposed tubes extending radially in all directions from the inner shell to the outer shell and opening at their inner ends through the inner shell and at their outer ends through the outer shell, said tubes being disposed at spaced distances longitudinally of the outer and inner shells, a heating means carried by the outer shell and having apertures whereby air may be allowed to enter past said heating means into the space between the shells, an element having a damper and disposed rearward of the rear ends of the outer and inner shells, means for causing the air in the space between the shells to circulate around the inner shell past said tubes and out into the space between the rear end of the inner shell and said element, and a suction fan casing forming a continuation of the outer shell and having a suction. fan therein.

9. A heater of the character described, including an air heating chamber and a suction fan casing in advance of said chamber, a suction fan therein, a base, means for tiltably supporting the air heating chamber and the suction fan casing for tilting movement in a vertical plane, said means including uprights extending from the base and pivotally connected to the heater, an arcuate bar fixed to and supported by the heater, the base having a groove through which the arcuate bar slides longitudinally, and means for locking the arcuate bar to said base in any tilted position of the heater.

10. A heater of the character described, including an air heating chamber and a suction fan casing forming a forward continuation of the chamber, electrical means for heating the air within said chamber, an electric motor for the fan, a base, supports extending upward from the base and pivotally connected to the heater on each side thereof, an arcuate bar carried by the heater, the base having a channel for the bar whereby the heater may be tilted in a vertical plane, the arcuate bar being channeled upon one face, conductors for the heater and for the motor mounted within said channel, switches mounted on the arcuate bar for controlling the flow of current to the motor and to the heater, and means for connecting said conductors to a source of current and including a socket carried by the arcuate bar.

11. A heater of the character described, including a fan casing, a motor therein and a fan carried by the motor, the motor and fan being removably mounted within said casing, the motor including a frame surrounding the motor and having a lug extending parallel to the axis of the fan, a base plate detachably mounted upon the rear end of the motor and legs extending outward and radially from the base plate and normally disposed within the fan casing, the base plate being detachable from the motor and engageable with said lug to thereby support the fan when removed from the casing.

12. A heater of the character described, including an outer shell and an inner shell spaced from each other, walls connecting the outer shell with the inner shell at the ends of said space, an electrical heating element mounted in the outer shell or wall and having openings whereby air may enter said space, a plurality of radially directed thin-walled metallic tubes disposed between the outer and inner walls and opening through said walls, an upwardly and outwardly extending flange on said exterior shell, a cap detachably engaged with said flange and having damper controlled openings, a rear wall of the space between the shells having an opening disposed remote from the heating element and discharging against said cap, a cylindrical fan casing flanged at its rear end and detachably engaging the forward end of the outer shell, said fan casing at its forward end being flanged, an outwardly flaring throat member detachably engaged with said last named flange and extending into the fan casing and having a screw threaded flange at its inner end, a fan and motor supporting frame including a ring having screw threaded engagement with the flange on the flaring element, a motor and fan supported by said frame within the fan casing, a base, and means carried by the fan casing and outer shell for tiltably engaging said base.

13. A heater including outer and inner spaced shells, the inner shell defining a central chamber open at its forward end, a plurality of metallic tubes passing through the space between the shells and opening through the outer and inner shells, the tubes extending transversely of the length of the chamber and being disposed at spaced distances longitudinally along said shells, means for drawing air through the tubes and expelling it on the forward open end of the chamber, a heating element associated with the shells constructed and arranged to heat the space between the shells, and means for admitting air to the space between said shells and into intimate contact with the heating element.

14. A heater including outer and inner approximately concentric shells, the inner shell defining a central chamber open at its forward end, a plurality of thin-walled metallic tubes passing through the space between the shells, each tube being open at its outer end to the exterior air and at its inner end opening into the central chamber, the tubes extending transversely of the length of the chamber and being disposed at spaced distances longitudinally along the length of the shells, means disposed within the central chamber for drawing air through the tubes and expelling it from the forward open end of the chamber, and means for heating the air in the space between the outer and inner shells.

15. A heater including outer and inner approx imately concentric shells, the shells being spaced from each other to provide an air space between the shells, the inner shell defining a central chamber open at its forward end and a plurality of metallic tubes passing through the space between the shells, the tubes opening at their outer ends to the outside air and at their inner ends opening into the central chamber, said tubes extending transversely of the length of the chamber, a rotary fan disposed at the forward end of the chamber for drawing air through the chamber and thus drawing air through the tubes, a heating element disposed between the outer and inner shells, and means for admitting air into the space between the outer and inner shells and into intimate contact with the heating element.

16. A heater of the character described, including an outer shell and an inner shell spaced from each other, the inner shell defining a central chamber open at the forward end, a plurality of metallic tubes passing through the space between the shells and opening through the outer and inner shells, the tubes being disposed transversely of the length of the chamber and being disposed at spaced distances longitudinally of the length of the shells, means for causing a current of air to pass longitudinally through the central chamber to thereby draw air inward through the tubes and expel it from the forward end of the chamber, a heating element associated with said shells and constructed and arranged to heat the air in the space between the shells, means for causing air to enter into the space between the outer shell and the inner shell and into intimate contact with the heating element, a member closing the rear end of the outer shell, the inner shell terminating short of said member and said member having apertures, and a damper controlling the passage of air through said apertures.

1'7. A heater of the character described, including an elongated casing, a fan disposed adjacent one end of the casing, means for admitting air to the interior of the casing and heating said air, a base, a pair of uprights extending from the base and pivotally connected at their upper ends to the center of gravity of the casing, the base being longitudinally slotted and an arcuate bar attached to the casing adjacent its opposite extremities and sliding through said slot, and means for clamping the arcuate bar in any adjusted position within said slot.

ALVAN O. HAY.

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