US1751754A - Electric heater - Google Patents

Description

March 25, 1930. E. B. ovERsl-HNER-`v` l j 1,751,754

ELECTRIC HEATER Filed Jan. 24, 192`9 2 SheetsvSheet l .g March 25, 1930. E. B. ovERsHlNER ELECTRIC HEATER 2 sheets-sheet 2 Filed Jan. 24, 1929 W.. Y UB Y M @l a d f L@ Patented Mar. 25, 1930 UNITED STATES PATENT OFFICE ELLSWORTH B. OVERSHINER, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF TO FLORENCE IVI. JACKSON, OF CHICAGO, ILLINOIS ELECTRIC HEATER Application led January 24, 1929.

My invention relates to heaters of the type which are dependent upon electricity as t-he source of energy, and has to do more particularly with suoli devices which are particularly adapted for heating a room or other enclosure such asa garage, factory, shop, etc.

Modern theory and practice in heating engineering have proven that a heating device is most efficient when the heat generated thereby is directed, as by a. fan or the like, in the form of a current of heated air to the point where the heat is desired, or into the room where it is required. It has been found diiiicult, however, to apply this principle to electric heaters for the reason that a device of this type does not begin to function efiiciently until the heating coils thereof begin to glow at a substantially red heat and if a current of air is continually played upon the coils they are never permitted to attain such a degree of heat as to become efcient. The result is that the air eurent which is directed over the heating coils is so slight-ly warmed thereby that, when diluted with the cold air of the room, its effect in imparting heat to the room is negligible.

I have found that an electric heater may rbe made exceedingly eificient if, instead of playing a continuous stream of cold air upon the heating coils, the coils are permitted to become incandescent and a gust or stream of air then blown over or through the coil, the stream discontinued, and the cycle repeated. The time required for a coil to become heated to incandescence may be made very brief, and hence the operating cycle may be very rapid.

An object of my invention, therefore, is to provide such a heater of the electric type which will be extremely eiiicient, simple in construction, inexpensive to manufacture,

and durable.

Another object of my invention is to provide a device of the type referred to which will furnish a series of intermittent gusts or blasts of heated air at very short intervals which. in effect, will constitute substantially a continuous current of heated air.

Many other objects and advantages of the Serial No. 334,639.

construction herein shown and described will be obvious to those skilled in the art from the disclosure herein given.

To this end my invention consists in the novel construction, arrangement and combinati-on of parts herein shown and described, and more particularly pointed out in the claims.

In the drawings, wherein like reference characters indicate like or coresponding parts:

Fig. 1 shows a top plan view of a device embodying my invention;

Fig. 2 is a side elevation of the same;

Fig. 3 is a front elevation of the same taken from the side opposite the motor;

Fig. 4 is a sectional View taken on the line 1 4L of Fig. 3; and

Fig. 5 is a sectional view taken on the line 5-5 of Fig. 3.

In the preferred embodiment shown in the drawings, I provide a bed plate 10 upon which is mounted a suitable bracket 11 supporting a motor 12. -his motor is preferably electrical and may be of any suitable type, Attached to one end of the shaft 13 of the motor is a fan 14 and the other end of the shaft carries worm 15 which meshes with a worm gear 16. The worm gear 16 is secured to a shaft 17 rotatably mounted in a bearing` sleeve 18 which is preferably integral with a bracket 19 secured to the motor 12 and secured to the other end of the shaft 17 is a disk 21 having a cam groove 23 therein. (See Fig. 1.) This cam comprises circular dwell 23a and a pair of radial grooves 23h.

It will be noted from an inspection of Figs. 1 and 2 that the disk 21 has a bearing pin 25 extending axially from its hub, which pin rides in a slot 26 forme-d adjacent one end of a link 27. A pin 28 secured to the link 27 is slidably disposed in the cam slot 2% of the disk 21.

A casing 30 is mounted on the bed plate 10 for housing an electric heater 32. The heater 32 may be of any suitable type or arrangement, but as shown, preferably comprises a plurality of coils 33 arranged in spaced relation in a plane transverse to the direction of `shutters nearest it.

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flow of air from the fan lll, the coils being supported by means of plates 35 disposed at the tops and bottoms thereof. A plurality of shutters 37 are pivotally mounted in the casing 30 on opposite sides of the heating unit 32, each of the shutters 37 having an axial pin 38 disposed in suitable bearings` at the top and bottom of the casing. At the top, the pins 38 are secured to levers 40. At their opposite ends, the ylevers l() carryV bearing pins 4l which are slidably disposed in slots liof a spider-like member 45, The member l5 comprises a central plate i6 (see Fig. l) and a series of oppositely ldisposed arms 4e? having slots 42 therein. rthe central plate l-of the member l5 has a pair of longitudinal slots 43 therein which slidably engage guide pins i9 secured to the top of the casing 30.

A-pin secured to the top of the plate 46 of the member i5 slioably engagesa slot 52 formed in one arm of a bell-crank lever 53 which is pivoted to the casing 30 as at 55. rlhe otheriend of theV bell crank lever 53 is pivotallyV secured to the link 27 as at 56.

In the operation of the device described above,fthe heating unit 32 and the motor l2 are connected to suitable source of electrical energy (not shown). Assuming that, in its initial condition the shutters 3Tare closed, as shown clearly in Fig. 3, the fan 14 will be functionless, inasmuch as it will merely direct a iiow of air against theoutside of the Hence, the coils 33 of the heating unit 32 will be permitted to heat up to the glowing point. Meanwhile, the motor shaft will have been rotating the disk 21,*through the worm and worm wheel constituting a speed reducing device, and the pin 23 of the linlr 27 will have been following one of the radial portions 23b of the cam groove v23 inthe dislr. Hence, by the time the coils have become heated to the glowing point, the link 27 will have been moved to tie left (Figs. i and 2) by means of the cam slot and the bell crank lever 53 will have been rotated on its pivot 55, moving the spider-like member Li5 and the levers l0 and shutters secured thereto. Therefore, when the pin 23 is traveling in the circular dwell 23a of t ie cam'groove '23, the shutter 37 will be maintained for an appreciable length `f :time in the open position as shown in Fig. and in dotted lines in `Fig. 5. During .this ime, of course, a. current of air is being blownby the fan 14 through the heating coils 33 and outfinto the roomV or other points where the heat is desi-red. is soon as the pin .8 reaches the end of the circular dwell and `follows one lof the radialportions 23h of the camgroove, the iinlr El? will be drawn to the right (Figs, l and 2) andthe shutters quickly closed. ".ihe cycle will then befrepeated.

it will be understoodof course, `that the device is so designed witlrrespectto the cam groove 23 and the various gearings that the shutters will be maintained in the open posi-- tion just sufficiently long for the heating coils to become cooler, and tiat the shutters will be maintain-et in the closed position a suiii' cient Vlength oftime for the coils to become incandescent andno longer. In other words, the shutter operation will be so timed to afford the most ethciency. Y

it will be readily apparent that the sequence of theioperations of opening and closing the, shutters may be made so rapid that in effect a more or less or substantially continuous currentof heated air is maintained. This construction permits smaller coils to be employed with increased efficiency, andreduced cost of operation. In fact, va small heater embodying my improvements, gives more satisfactory heat at less cost `than the larger heaters without my improvements. it will also be apparent that the heating unit 35 is not necessarily restricted to an electrical device, although my invention is particularly applicable to such a type of heating unit. @ther types 0f Aheaters which are rapidly cooled may be substituted for the electrical heating` unit shown and "described, and itrwill be understood that I am limited to this type of Yheater only tothe extent indicated in the appended claims.

Having thus described my invention, itis obvious that various immaterial modifications may be made inthe same without departing from the spirit .of my invention; hence do not wish to be understood as-limit,V ing myself to the exact form, construction, arrangement and combination of parts yherein shown and describethoruses mentioned.

Vilhat I claim as Anew and r,desire to secure by vliet-ters Patent is:

l. ln a device of theclass described, -a heating unit, means for projecting a current of :air over said unit, and means for 'intermittently interrupting said currentfso as to permit said unit to acquire incrementsof heat l between successive blasts.

2. ln a device ofthe class described, a

4heating unit, means for projecting a current of fair over said unit, and means for intermittently shielding said heating unit from said air current so asto permit saidunit to acquire increments of y-heat betweensuccessive blasts.

3. ln a device ofathe class described, a heating unit, means for projecting, a current of` Vsides of saidcasing in the pathof airfrom said projecting means, and automatic means for intermittently opening and closing said shutters simultaneously.

5. In a device of the class described, a heating unit, means for projecting a current of air over said unit, and means operated by said air projecting means for intermittently shielding said heating unit from said air current so as to permit said unit to acquire increments of heat between successive blasts.

6. In a. device of the class described, a heating unit, means for projecting a current of air over said unit, a shutter disposed between said heating unit and said air projectlng means, and means operated by said air projecting means for intermittently opening and closing said shutter.

7. In a device of the class described, a casing, a heating unit disposed Within said casing, means for projecting a current of air through said casing and over said heating current, a movable shutter disposed on the opposite sides of said casing in the path of air from said projecting means, and means operated by said air projecting means for intermittently opening and closing said shutters simultaneously.

8. In a device or' the class described, a heating unit, means for projecting a current of air over said unit, means comprising a cam and controlled by said air projecting means for intermittently shielding said unit from said air current so as to permit said unit to acquire increments of heat between successive blasts.

9. In a device of the class described, a heating unit, means for projectinga current of air over said device, a shutter disposed between said heating unit and said air projecting means, and means comprising a cam and controlled by said air projecting means for intermittently opening and closing said shutter.

l0. In a device of the class described, a casing, a heating unit disposed Within said casing, means for projecting a current of air through said casing and over said heating unit, a movable shutter disposed on opposite sides of said casing in the path of air from said projecting means, and means comprising a cam and controlled by said air projecting means for intermittently opening and closing said shutters simultaneously.

In Witness whereof, I hereunto subscribe my name this 8th day of January, A. D. 1929.

ELLSIORTH B. OVERSI-IINER.

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