US2482268A - Electric heater - Google Patents

Description

mames Sept. 20, i949. B, J. GRAYCAREK ELECTRIC HEATER Filed Dec. 15, 1947 Patented Sept. 20, 1949 ELECTRIC HEATER Benjamin J. Graycarek, Manitowoc, Wis., assignor of one-half to George W. Noll, Manitowoc,

Wis.

Application December 15, 1947, Serial No. 791,914

(Cl. 21B-39) 4 Claims.

This invention relates to electric heaters and be used for other purposes.

Objects of this invention are to provide a novel form of electric heater which is arranged to be attached to the blower side of :a vacuum cleaner or to some other source of -air under a slight pressure and which is .arranged to first preheat the air by passing the Iair through the central portion of the porcelain body of an electric heater and thereafter diverting the air rearwardly and passing it over the heating wires of the heater so that the air is super heated, and thereafter directed forwardly from the device.

Further objects are to provides. heater so that it is impossible for sparks or burning dust particles to be discharged from the heater, the arrangement being such that t-he air that passes over the heated wires is caused to travel rearwardly and thereafter is deflected forwardly, thus giving a long travel for the air and causing any burning dust or `other sparks to be driven against the rear portion lof the heater and thus extinguished.

Further objects are to provide a novel form of electric heater-which is of very Asimple construction and which may be cheaply made and most easily assembled.

An embodiment of the invention isy shown in the accompanying drawings, in which- Figure 1 is .a vertical sectional view through the major portion of the heater.

Figure 2 is a iront end View partly broken away.

Referring to the drawings, it will .be seen that the heater comprises a body portion l which is generally circular :and which may be formed of plastic, if so desired, or of metal. In the event it is formed of plastic it must be of a type which will not soften under heat. If desired, the front portion or discharge end 2 of the heater may be slightly converged or contracted. The rear portion 3 of the heater is provided with an annular groove 4 which, in reality, constitutes la half torus and serves to direct the :air lforwardly as will be apparent as the description proceeds. This rear portion is provided with a reduced inwardly projecting extension 5 which is provided with a plurality of spaced pins 6 adapted to be received in bayonet slots 'l formed in the porcelain cylinder 8 4of the electric heater. This construction allows the ready insertion or removal the cylindrical porcelain member 8 which is provided with spiral grooves that receive the heating, spirally coiled wire 9. It is to be noted that the wire 9 projects outwardly a considerable distance from the porcelain cylinder 8 so that the air passing rearwardly actually passes between `the successive convolutons of the wire and thus is thoroughly heated. The :air is also preheated by vpassing forwardly from the inlet opening IU of the heater. This inlet opening I0 is supplied with air under a slight pressure from any suitable source as from the blower end Il of a vacuum cleaner.

The main .body portion of the heater is provided with an inner shell or cylindrical member I2 which is integral with the outer member I and may be joined thereto by a plurality of struts I3. This inner shell I 2 is located between the porcelain shell 8 Iof the heater and the outer body portion I. The outer end of the shell I2 is provided with a plurality of pins I4 which are received in bayonet slots I5 formed in ia front cap member I6. This Vfront cap member is preferably formed of metal Ias it i-s subjected to a considerable amount of heat from the impinging heated air. This front cap I6 is provided with an annular groove I1 which forms a half torus and which has a central cusp I8. It serves Ito direct the oncoming air passing outwardly from the porcelain tube or shell 8 rearwardly so that it crosses fthe heating wires or heating elements 9 as previously described. The heating wires or heating elements may be connected to a plurality of binding posts or bolts I9 from which the outwardly extending leads or conductors 20 may pass. It is preferable to provide a pair of insulating tubes 2l of suitable material `which are screw threaded as indicated at 22 into the shell I2. These insulating tubes 2l are provided `with notches 23 adjacent the bolts I9 so as to receive the conductors or leads 2B. When the leads 20 are connected to the binding posts or bolts I9 they are drawn up snugly and thus prevent rotation of the porcelain cylinder 8 and thus prevent detachment of the cylinder 8 from the reduced extension 5 of the body portion.

It is a very easy matter to assemble this device for it is apparent that the heating element, consisting of the porcelain cylinder 8 and the wires 9, is iirst inserted from the front of the device and the bayonet slots 1 `are interlock-ed with the pin 5. Thereafter the conductors 20 are clamped to the bolts or binding posts I9 and are threaded through the tubes 2| which are screwed into the of the heating unit. The heating unit comprises shell l2 as stated. After this the front cap I6 3 o1' front air de'ector is locked to the shell I2 by the interengagement of the bayonet slots I and the pins I4 as described hereinabove.

If desired, the body portion may have integrally or otherwise formed clamping means indicated generally by the reference character 24 so that it may be clamped to any suitable support.

It is to be distinctly understood that the main body portion consisting of the shells I and 2 and the rear portion 3 and the struts or spacers I3 may be formed of any suitable material whether it be metal or plastic or other suitable material. The front cap I6 likewise can be formed of any suitable material, though it is preferable to form this member of metal.

It will be seen that a novel form of electric heater has been provided by this invention which is of simple construction and which is very effective and highly efficient in heating the air as the air is rst preheated and thereafter super heated by rst being passed through the heating unit and thereafter being passed around the heating unit so that a high degree of heat transfer from the heating unit to the air is obtained.

It is to be understood that this device can be used as a hair drier or as a space or room heater and can be made in any size desired.

It is to be understood that while a cylindrical body portion and cylindrical shells have been illustrated, that nevertheless the expression cylindrical is not to be interpreted in a limiting sense but is intended to cover any tubular shape whatsoever whether it be truly circular in cross section or whether it be polygonal, or whether it have some other shape.

Although this invention has been described in considerable detail, it is to be understood that such description is intended as illustrative rather than limiting, as the invention may be variously embodied and is to be interpreted as claimed.

I claim:

1. An electric heater for heating a large volume, low pressure stream of air comprising a body portion having an outer shell and an inner shell spaced from said outer shell to provide a discharge passageway for heated air, an electric heater having a central tubular body portion and a heating element on the outer side of said tubular body portion, said electric heater being located within said inner shell and spaced from said inner shell,

d means for directlng a current of air successively forwardly through said central tubular body portion, rearwardly over and in direct contact with the heating element between the heater and the inner shell, and forwardly and outwardly between said inner and outer shells.

.2. An electric heater comprising a body portion having outer and inner spaced shells, an electric heater within said inner shell, and means for directing a current of air forwardly through said electric heater to preheat the air, rearwardly over the outer side of said electric heater in direct contact therewith to super heat the air, and forwardly between said inner and outer spaced shells to discharge the heated air through a zone separated off from said electric heater.

3. In a device of the class described for heating a large volume, low pressure stream of air, a hollow cylindrical heater, means for directing a current of air forwardly through said heater, a half torus-shaped deflector located in front of said heater for directing the current of air rearwardly over the outer side of said heater, and means for directing the current of air away from said heater.

4. An electric heater comprising a cylindrical body portion, anjnner cylindrical member supported from said body portion and spaced from the inner wall thereof to provide an annular air discharge passageway, said body portion being open at the iront and having a closed rear portion provided with an air inlet opening for directing a current of air inwardly, a hollow electric heater detachably supported from the rear of said body portion with therhollow interior of said heater in alignment with said inlet opening and located within said inner cylindrical member and spaced therefrom, and a circular cap member detachably attached to the front of said inner cylindrical member and having an annular recessed portion'for receiving the heated current of air from the interior of said heater and directing such heated air rearwardly between said heater and said inner cylindrical member to super heat said air, the rear part of said body portion having an annular recessed portion for receiving the air from between said inner cylindrical member and said heater and arranged to direct the super heated air outwardly through the discharge passageway between said inner cylindrical member and said body portion.

BENJAMIN J. GRAYCAREK.

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

UNITED STATES PATENTS Number Name Date 1,252,614 Pieper et al Jan. 8, 1918 1,949,658 Remseth et al Mar. 6, 1934 2,028,095 Tully et al Jan. 14, 1936 2,042,264. Levenhagen May 26, 1936

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