US2530721A

US2530721A - Heater or stove

Info

Publication number: US2530721A
Application number: US56215A
Authority: US
Inventors: Perlman Samuel Donald
Original assignee: Individual
Current assignee: Individual
Priority date: 1948-10-23
Filing date: 1948-10-23
Publication date: 1950-11-21
Anticipated expiration: 1967-11-21

Description

Nov. 2l, 1950 s. D. PERLMAN HEATER 0R sTovE Filed Oct. 25, .1948

Patented Nov. 21, 1950 y UNITED STATES PATENT OFFICE 2 Claims.

This invention reiates to heaters or'stoves, and while of general application, is generally designed for heating the contents of a can of food or other material while in the original can in which it was packed.

It is an object of the invention to provide for bringing the contents of a can of what is generally known as canned goods to a boiling condition, without burning or scorching the contents of the can, within a predetermined minimum of time and with the consumption of a minimum amount of fuel.

Another object of the present invention is to provide a device for supplying only that portion of the products of combustion which have not yet burst into flame to the bottom end wall of the can to be heated so as to prevent burning or scorching of the bottom portion of the contents of the can, and subsequently to supply hotter products of combustion, such as the name, to the lower portion of the upright walls of the can above the bottom end wall thereof, so as to heat gradually a larger area of the contents of the can and thus prevent burning or scorching of such contents.

It is a further object of the invention to provide a simple and improved heater or stove of minimum cost and minimum weight, and of maximum durability and effectiveness. These stated characteristics make the present invention highly useg,

ful for military personnel, particularly in heating individual canned rations.

The device may be used out of doors as well as within a house, and when used out of doors, will function satisfactorily without requiring that it be shielded from drafts. It is capable of repeat* ed use, and may be of a size to be carried in a pocket of the clothing but size is not of the essence of the invention. The heater will function properly and satisfactorily even though in a wet condition.

With these and other objects in View, the present invention consists in the combination and arrangement of parts, as will be hereinafter more fully described, shown in the accompanying drawings and particularly pointed out in the appended claims, it of course being understood that changes in the form, proportion, size and minor details may be made, within the scope of the claims, without departing from the spirit or sacrificing any of the advantages of the invention.

In the drawings:

Figure 1 is a vertical central longitudinal sectional view of a heater or stove showing one ernbodiment of the present invention.

Figure 2 is a fragmentary perspective View of a lower portion of the body of the heater.

Figure 2a is a detail fragmentary sectional View showing a different arrangement of wick for use with a liquid fuel.

Fig-ure 3 is a fragmentary vertical sectional view similar to Figure 1 but showing another embodiment of the invention.

Figure 4 is a fragmentary side elevation of means for supporting the can to be heated in accordance with the embodiment shown in Figure 3 of the drawings.

Figure 5 is a fragmentary top plan View of Figure 4.

Figure 6 is a fragmentary side elevation of Figure 3.

As embodied in Figure 1 of the drawings, the heater or stove of the present invention includes a body member I which is open at its top and at its bottom and may be of any special or preferred shape or configuration. Disposed centrally Within the open bottom portion of the body I is a hearth 2, shown in Figure l as a pan having a marginal upstanding wall 3 provided at its top edge with an outwardly directed horizontal shoulder 4 resting upon the substantially horizontal support 5 projecting inwardly from the body l of the heater. This supporting member 5 may be of any suitable nature and may consist of an annular series of members bent upwardly and inwardly from the lower edge portion of the body as well indicated in Figure 2 of the drawings. By this manner of producing the supporting meinbers 5, an annular series of feet l are provided for the body l, and between each pair of successive feet there is an opening 6 produced by the upward displacement of the part 5. These openings 6 constitute air induction ports intended for the admission of atmospheric air into the lower portion of the stove body at the outer periphery thereof, as will hereinafter be explained. While thisl specic manner of producing a support for the hearth 2 is satisfactory, any other way of supporting the hearth within the body and above the lower edges of the feet 6 may, of course, be employed. By employing a pan shaped hearth, either solid fuel or liquid fuel or both may be employed, but it will, of course, be understood that the pan form of hearth is not essential to the operation of the present invention, as other forms may be employed, such as a flat plate, particularly where solid fuel is to be employed in the heater or stove. A wick I2a may be provided in the pan and within the bottom portion of the shell l2 when liquid fuel is used. As shown in Figure 2a, the wick iZa may be positioned between the wall 3 of the pan and the bottom portion of the shell i2. Upon the top of the hearth there is a layer or lining il of heat insulation for the purpose of minimizing escape of heat downwardly from the bottom of the hearth. Likewise, a liner or" heat insulatingI material may be provided within the body i and lying snugly against the inner walls thereof to retain heat within the body and minimize radiation thereof.

The can to be heated, shown at III, may be supported on the top of the shell I2, or on an annular shelf-like part Il, carried by the body I or by the shell I2 and located at or about the level of the top of the shell. Disposed concentrically within the body l is the cylindrical shell l2, the bottom edge of which rests within and upon the hearth member 2. This shell or drum is open at its bottom, although it could be closed at its bottom and such closed bottom could provide a hearth for the present heater or stove. A top plate E2 closes the top of the shell or drum i2 and constitutes a horizontal baiiie as will hereinafter appear. The body walls or this shell i2 are provided with an annular series of openings i3 of suitable size and shape for the passage therethrough or products of combustion as will hereinafter appear. The body I of the stove and the upright walls of the shell I2 dene an annular combustion chamber, and therefore the horizontal member i I should not seal or close the top of the combustion chamber. It may be provided with openings, one of which has been shown at iii, for upward passage of heated products of combustion. If the part II is carried by the shell i2 then said part Ii could terminate short of the wall l, so as to provide an opening or port for the upward passage of products of combustion.

In the operation of the present heater or stove, any suitable fuel is placed on the hearth 2 and then the fuel is ignited in any preferred manner, after which the can it is placed upon the top of the shell I2 or the support lI. The internal diameter of the body I of the heater should, of course, be slightly greater than the external diameter of the can to be heated. Primary air passes inwardly through the openings or ports t in the lower marginal portion of the body I, and then upwardly between successive supports 5 and thence inwardly through the bottom portions oi the ports or openings i3 so as to supply primary air for the purpose or combustion of the fuel on the hearth 2. 1f desired the parts 5 may have openings therein, as best shown in Figure 2 of the drawings, through which openings primary air may also pass. The heated products of combustion and flame rising from the fuel pass outwardly through the openings or ports i3 into the annular combustion chamber, defined by the body i and the shell i2, from which they pass upwardly through the openings lli in the shelf or support member il and thence out of the top of the body and along the upright walls of the can. The top edge portion of the body I is provided with openings or ports i5 for the inflow oi secondary air to promote combustion of the unconsumed products of combustion rising irough the body of the heater.

From the foregoing explanation, it will be seen that the maximum combustion of the fuel will be around the outer peripheral edge thereof within and close to the shell i2, and that the hottest portion of the flame will be in the annular space between the body I of the heater and the bottom 4 peripheral edge and the lower portion of the up-a right walls of the can.

The distance between the hearth 2 and the bottom of the baiile i2 or the can IEl is such that before the heated products of combustion rising from the central portion of the fuel can break into a ilame with its hottest portion at the center of the barile and the center of the bottom of the can, such baille will cause the heated products of the combustion to spread radially outward and through the ports or openings I3 into the annular combustion chamber around the shell I2 and then break into an annular flame at or slightly above the annular support il and .y around the bottom edge of the can It! and the lower portions of the upright walls of the can. Due to this handling of the heated products of combustion, there will be only a small amount of heat applied to the bottom of the can I3, for the reason that the hottest portion of the ilame is in the form of a circular band around the lower outside walls of the can upwar 'ly from the bottom edge thereof, wherefor the maximum heat generated by the device will be spread around the exterior walls of the can instead of being applied directly to the center of the bottom end wall of the can. Burning or scorching of the contents or the lower portion of the can along the bottom thereof will not occur for the reason that only a very small portion of the heat from the burning fuel will contact the bottom end wall of the can. Moreover, as the ilaine is spread out and its hottest portion applied in a circular band to the upright cylindrical walls of the can, that portion of the can to which the heat is applied is of materially greater area than the bottom end wall of the can, yet it is suicient to heat the contents of the can, without burning the same, within a minimum predetermined perod of time with a minimum consumption of fuel.

As the top of the shell l2 is closed, and in order to facilitate the placing of fuel on the hearth, the shell may be removably fitted within the body of the heater. If fixed within the heater, then the baffle top i2 thereof shouid be displaceable so as to permit the introduction of fuel through the top of the shell and on to the hearth.

The present invention has been designed to meet certain specications requiring the heating of the contents of the can to the boiling point, without burning or scorching the contents thereof, within a predetermined minimum of time, and with the consumption of a minimum amount of fuel.

When the heater is in operation, there is no noticeable flame in the space between the top edge portion of the body of the heater and the can, yet a very definite blue flame is noticeable within the body or" the heater below the top edge thereof and at or about the lower marginal edge of the can, or in other words, at about the elevation or the support Il for the can. Accordingly, neither smoke, flame nor haze is visible at a short distance from the heater for the reason that the present invention accomplishes perfect combustion or, in any event, combustion of such a character that neither name, smoke nor haze is noticeable at a short distance from the heater.

By reason of the fact that the hearth 2 and the annular combustion chamber between the body I and the shell I2 are surrounded by a shield defined by the walls of the body, it is not necessary to provide some sort of a shield around the heater or at one side thereof nor to protect it against drafts when used in the open. Furthermore, the comparative lightness of the device is such that it cools off rapidly by radiation in a short period of time. In practice, it has been found that where the device is wet, even to the extent of where it has been plunged into a body of water, the fuel will ignite promptly, the heater will dry off quickly and function the same as where the device is dry at the outset.

While the construction shown in Figures 1 and 2 is strong, durable and light, nevertheless, its weight may be materially reduced without impairing its strength and durability, as will be seen by reference to the structure shown in Figures 3 to 6, inclusive, wherein it will be noted that the body and other parts of the device are embodied in reticulated or openwork form such as expanded metal. In this latter form of the device the body I6 is formed of a sheet of expanded metal which is folded upon itself so that the bend or fold I'I thereof constitutes the top edge of the body, whereby the body of the heater has spaced outer and inner walls I6 and I8, the latter terminating short of the bottom edge of the outer wall I6. Between the walls I6 and I8 there is a sheet of heat insulating material I9 which extends at its bottom belowthe lower edge of the inner wall I3 and terminatesl short of the top edge of the body.

The expanded metal sheet is bent along a line of openings therein so as to provide open top notches around the top edge of the body, comparable to the notches or openings I5 shown in Figure l of the drawings, for the introduction 1- of secondary air, as hereinbefore described. The inner wall I8 has its lower portion bent inwardly and upwardly as at 2| into a horizontal position so as to provide an internal annular shelf or support for the pan 2, which constitutes the hearth of the device just as shown in Figure 1 of the drawings. The pan 2 has an upstanding marginal wall 3 at its outer edge terminating at its top in an outwardly directed horizontal shoulder 4 resting on the shelf-like support 2| whereby the pan is supported in place. A sheet of heat insulating material 8 is disposed within the pan and supported on the bottom thereof as in Figure 1.

Within the body there is a cylindrical shell 22 of expanded metal having its lower edge seated within the pan 2 and its upper portion 23 bent outwardly into a substantially horizontal position so as to provide a support for the can I0. The

parts

22 and 23 of Figure 3 serve the same purpose as the parts I2 and II as embodied in Figure l.

In the expandedmetal form of the device, it will be seen that the sheet of heat insulating material I9 closes the openings in the inner and outer walls of the body from a point near the top of the body downwardly below the inturned shelf-like support 2l on the inner wall I8. By this arrangement, the burning fuel on the hearth 2 is protected against drafts while at the same time primary air may ow inwardly through the openings 24 in the bottom portion of the wall I6 beneath the lower edge of the insulating sheet I9 and thence through the openings in the shelflike support 2I and finally through the openings 25 in the cylindrical part 22 of the support for the can to be heated, thus admitting primary air over the top of the pan 2 and to the marginal portion of the fuel in the pan, so as to maintain combustion of the fuel around the outer 6 marginal portion thereof as distinguished from the central portion of the fuel, just as occurs in the embodiment shown in Figure 1 of the drawings. Secondary air ilows inwardly through the notches or ports 2l] at the top of the expanded metal body and over the top edge of the insulating sheet I9 as in Figure 1 of the drawings. It will, therefore, be understood that the fundamental features of the heater as illustrated in Figure 1 are also present in the expanded metal form, and the only difference resides in the physical condition of the materials. The reticulated or expanded metal form of the device materially reduces the weight of the heater while at the same time the strength thereof is preserved.

Although a wick has not been shown in Figure 3 of the drawings, it will, of course, be understood that a wick may be employed just as is shown in Figures 1 and 2a for the purpose of burning a liquid fuel.

The shell or drum I2 of Figure 1 and the shell or drum 22 of Figure 3 perform identical functions, the most important of which is to confine the products of combustion in a ring or band within and at the interior Walls of the shell or drum as distinguished from spreading radially outward in an irregular manner as would occur in the absence of the shell or drum. The products of combustion will eventually pass outwardly through the openings in the drum and in the form of a band and thence upwardly through the ue provided by the bottom side walls of the can and the top side walls of the body I where they will meet secondary air admitted through the openings I5 at the top of the body of the heater.

It will here be explained that it is necessary to prevent the direct upward escape of products of combustion through the top of the shell or drum, and for this purpose the latter is provided with a top I 2 as shown in Figure 1 so as to form a baie which spreads the products of combustion radially outward before they reach their a, highest degree of temperature, which high degree occurs in the annular space between the upright side walls of the can Ill and the body I. It now should be understood that the shell or drum I2, together with its closed top I2' provides a baille functioning as above described. The top member I2 of the drum could be omitted, in which event the bottom under wall of the can will constitute a horizontal balle in place of the part I2. In Figure 3 a baiile corresponding to the one designated I2 is not shown so as to illustrate how the bottom of the can I0 will function as a baille closing the top of the shell or drum. However, the shell or drum 22 may be provided at its top with a horizontal baille as indicated at I2 in Figure 5 of the drawings.

While a can supporting member II is shown in Figure 1 and at 23 in Figure 3, such supporting means are not' essential to the operation of the present invention and may be omitted, as the can to be heated may rest upon the top member I2' of the shell or drum or upon the top edge of the shell or drum in the absence of the parts II and 23. These parts II and 23 are provided primarily to center the top portion of the shell or drum within the body I of the heater and may or may not be connected to said body I.

Having thus described my invention, what I claim is:

1. A heater comprising a body having an open top, a hearth supported within the body, a mar- .'ner walls of the body, and having ports for the passage of products of combustion, the top por tion of the body having air induction ports located adjacent and above the top of the bale.

2. A heater comprising a body having an open top, said body being formed of a sheet of ex'- panded metal bent to form spaced upright walls with the bend of the material at the top of the body, the inner wall of the inner member of the expanded material terminating short of the bottom of the outer member thereof, insulating material between the Walls of the body to close the openings in said walls and terminating short of the top and bottom of the outer wall, a hearth supported within the body of the heater, a marginal baie formed of expanded metal and rising from the hearth, the top of the baiile terminating short of the top of the body and constituting a support for a receptacle to be heated, the openings in the upright walls of the baffle constituting ports for the inward admission 'of air to the hearth and for the outward escape Lof products of combustion, the openings in the outer wall of the body below the insulating material constituting ports for the inward admission of air to the vports -of the baiile, and the 'openings in the walls vof the body above the top of the -insulating material constituting ports for the ine ward admission of air.

SAMUEL DONALD PERLMAN.

REFERENCES CITED rifhe following references are of record in the iile 'of this patent:

UNI/TED STATES PATENTS Number Name Date 1,238,080 Ball d Aug. 28, 1917 1,487,474 Rhodes ca 1.-." Mar. 18, 1924 1,622,494 Cranston r Mar. 29, 1927 2,464,817 Laliberte Mar. 22, 1949 FCREIGN PATENTS Number Country Date 2,475 Great Britain of 1915 33,142 Norway Oct. 3, 1921 54,396 Switzerland July 12, 1911 480,588 France July 22, 1916 599,185 Germany J'une '27, 1934