US 2928386 A
Description (OCR text may contain errors)
March 15, 1960 Filed March 22, 1967 Fig. I
D. E. KEYT ET AL PORTABLE COOKING STOVE 2 Sheets-Sheet 1 MICHAEL M'. DUBlTZKY NORTON T. PIERCE KENWAY, JENNEY WHTER l- HILDREI'H ATTORNEYS March 15, 1960 D. E. KEYT ETAL PORTABLE cooxmc; STOVE 2 Sheets-Sheet 2 Filed March 22, 1957 2 P M 8 O 3 6 3 58 4 02 8 4 3 w 5 4 W F L E U F INVENTORS DONALD E. KEYT MICHAEL M. DUBITZKY NORTON T.
PIERCE B KENWAY. JENNEY, WITH! 81 HILDRETH ATTORNEYS m d s i PORTABLE COOKING STOVE Donald E. Keyt, Bedford, Michael M. Dubitzky, Stoneham, and Norton T. Pierce, Concord, Mass., assignors to Arthur D. Little, Inc., Cambridge, Mass., a corporation of Massachusetts Application March 22, 1957, Serial No. 647,763
6 Claims. (Cl. 126-38) Portable cooking stoves used by the Armed Forces, campers and exploration parties are usually objectionably bulky, heavy and cumbersome, andhence cannot be conveniently carried on the person. Portable stoves which use solidified alcohol, although overcoming these objections, nevertheless present the difliculty of requiring the transportation of an adequate supply of fuel which has a relatively low caloric value as compared with gasoline and motor fuels which are usually readily available in all transportation vehicles.
The principal object of the present invention is to provide a compact, light-weight efficient cooking stove suitable to supply the needs of a man in the field and designed so that it can be conveniently carried .either on the person or in a pack, thereby overcoming theaforementioned objections.
Further objects relate to features of construction and will be apparent from a consideration of the following description and the accompanying drawings'wherein:
Fig. 1 is a top plan view of a stove. constructed in accordance with the present invention;
Fig. 2 is a vertical section through the stove shown in Fig. 1;
Fig. 3 is an enlarged section through the priming pump and tank; and
Fig. 4 is an enlarged section through the control valve and associated burner assembly.
; In accordance with the present invention we provide a portable cooking stove comprising an annular-shaped fuel tank for holding a supply of gasoline or other motor fuel, the tank having a feed line that extends radially inwardly, and within the confines of the fuel tank is a valve, the lower part of which is connected with the feed line and its upper part carries a burner assembly which may be of conventional design .and construction. The upper end of the burner assembly is above the level of the fuel tank. At a level below the upper end of the burner assembly but above the level of the tank, is an annular shield having a depending skirt secured to or integral with its inner periphery and positioned between and in spaced relation tothe burner assembly and the ing a cooking utensil above the burner assembly, thereby insuring complete combustion of the fuel.
The fuel tank may be provided or 'connectedwith a priming pump for maintaining sufficient pressure to insure proper feeding of the fuel and the valve may be provided with a suitable actuator for controlling the flow of fuel to the burner assembly. If desired, the tank and valve may be mounted on a spider-like base which insures a ready flo wof air to the burner assembly and the I entire apparatus may be conveniently packed in a shallow cylindrical container which provides a cooking utensil. Due to the construction and arrangement of the above parts the entire stove may have a diameter as small as five inches and an overall height of the order of 2161 pending legs 2 and mounted on the base is a toroidalshaped fuel tank 4 having a feed line 5 which extends radially inwardly. Mounted on the base 1 and concntrically disposed relative to the tank 4 is a control valve 6 (Fig. 4), the upper part of which supports a burner assembly designated by the numeral 8 (Figs. 2 and 3). I
extends outwardly beneath the base 1 and its outer end portion projects through an opening in one of the legs 2- and is bent so as toprovide a handle 30 by means of.- which the crank may be convenientiy manipulated. By, swinging the handle 30 through an angle of 180 the;
- with av converging The valve 6 comprises a sleeve 10, the lower part of which is brazed or otherwise secured within an opening in the base 1 and its inner periphery adjacent to its upper'-' end is formed with a conical shoulder 12 (Fig. 4). valve member 14 is axially slidable within the sleeve 10 and the upper part of this member is formed with a re duced end 15, and its lower part is formed with a depending stem 16. The side wall of the sleeve is formed with an inlet opening 18 which receives the end of the feed line 5, and the construction and arrangement of the parts are such that the reduced end 15 is above the inlet 18 when the valve member is in closed position.
At the junction of the reduced end ISand body portion 14 there is a circumferential groove in which an O-ring 20 fits so that its outer periphery engages the shoulder 12 to seal off fluid flow from the inlet 18 to the chamber 22 above the valve member 14. The lower part of the valve member below the inlet 18 is formed with a circumferential recess which receives a second Q-ring 24 and its outer periphery tightly fits the sleeve 10 so as to seal off fluid flow from the inlet 18 to the lower end of the sleeve. Thestem 16 is formed with an opening which receives theoffset end 25 of an operating.crank 26 which projects through an opening 28 formed in the sleeve. The opposite end of the crank 25 valve member 14 may be raised and lowered to and from closed position.
The upper end of the sleeve 10 is secured to or formed integral with a dish-like pre-heating reservoir 32 (Figs. 2 and 4) and above this reservoir the sleeve is formed with a threaded portion which terminates in a beveled tube being rigidly secured in position by a nut 40 formed upper end 42 which clamps the end 38 in position.
The upper end of sleeve 10 and the tube 36 define a fuel chamber which communicates with the supply line Sjwhen the valve member is lowered and within this chamber is a roll ofmetallic screen 45 which provides, in
effect, a heating coil or distributor for insuring vaporization of the fuel after the parts have been pre-heated,
as hereinafter'more fully described. Threaded within, the upper end ,of the tube 36 is a fuel nozzle 46 having.
a central opening through which the fuel is. metered.
The lower end of a needle-like tapered pin 48 is suit ably secured to the upper end of the valve member 14 and the body portion of this pin extends upwardly through P ed .M 5. 9 9,.
lie .6 hen the al e is closed Since the valve mem ber 14, pin 48 and whisker 50 are movable as a unit, the whisker serves to prevent clogging of the nozzle by products of combustioniof the fuel 3 wThe burner assembly comprises a generally hetnispherical burner 52 having an open upperend anda lower end, formed with an opening tightly fitting about the peened over upper endsof a nut 54 which is threaded to the upper end of the tube 36. Thatportion of the burner 52 which surrounds the peened 'overend of the nut is provided with a plurality of spaced weep openings aeaasss "I V The cap 84 isfprovided with a small vent opening 97 (Fig; 3) so that the piston may be reciprocated without forced through ports .94 and 95 during -the pressure.
building up a positive or negative pressure within the chamber surrounding the rod 86. When the piston is reciprocated air is drawn into the cylinder through the rod 86 and valve 91 during the intake stroke and is stroke into thefinterior of the tank to build up a pressure .su'fiicient' to force the-fuel through the'inlet 5, valve 6 into the burnerjassem'bly, 8. The piston is reciprocated by means of an operating arm 98 secured to "the '55. through which liquid fuel may pass so as to run down into the reservoir 32, and between these openings and itsupper end the burner 52 is providedwith spacedair; intake openings 56. Across the top of the burner 52 is a circular plate 62 carrying tabs 64 which are connected to the burner so as to provide a loose fitting cover for flame retention.
Surrounding the burner is a frusto-conical radiant heat shield 58 which is connected to the burner by a plurality of .inwardly extending tabs .60. Extending about .-'.the
radiant heat shieIdSSand in spaced relation totheup'per part of the tank is. another annular radiant heat shield 66, the inner periphery of which is shaped to provide adepending frusto-conical skirt 68' which extends between and in spaced relation'to the burner assembly 8 and the inner periphery of the tank 4. The two reflective shields partially isolate the fuel tank from the heat of the burner and preventobjectionable overheating of the fuel tank.
Depending fromthe brazed or otherwise su'itablyse cured to the outer periphery of the shield 66 are a plurality of circumferentially spaced sockets '70, the
lower ends of which are brazed to the tank 4 Each socket receives the lower endof a retractable arm 72 consisting of a length of stiff wire bent at its central,
portionto provide an offset 74 engageable with the upper face of the shield when liftedffrom retracted positi on,-'shown by the broken lines of Figs. 1 and-2, and thenswung to cooking or utensil-supporting position, shown by the full lines of Figs. 1 and 2, in order to upper end of the piston rod, and the piston 88 and parts carried thereby are rotatable within the cylinder so that the operating arm 98 may be swung from pumping position (full lines of Fig. 1) to non-operating position (brokenrlines of Figgl). An additional port 99 is located at in thepump piston rod 86 so that the inlet valve will not be inadvertentlyjclosed ofi by thefinger of the operator,-and'a port100 in the cap 84 is provided so thatthepressure in the ta'nk 4 can be released before the i cap 84 is completely removed;
A summary o'ftheoperation of the stove is as follows: Assuming :that the-tank 4 contains a supply of gasoline or'thelike motor fucl as shown in Figs. 2 and 3, that the legs 76 and operating arm 98 are positionedas shown in the full lines of Figs. 2 and 3, and that the 'valve 6 is closed, the piston-88 is reciprocated a few times so as to build up a pressure within the tank 4,
1 after which the-handle is swung to open position-to permit "fuel to pass. through the supply .line into the burnersa'sjsernbly and then trickle down into the-preheating reservoir 32.: 'Whent'he reservoir has been filled the valve 6; is closed and fuel in the reservoir is ignited.
yjthetimethe fuelin'the reservoir has burned away, the generator 36hasibeenheated to fuel vaporizing tem perature and the valve 6 may thenfbe turned on. The
heated generator 36 andscreen 45 vaporize fuelpas sing from the chamber 22 sot'hat vaporized fuel is discarged provide an adequate supporting surface for the cooking utensil '75. The upper ends of the arms are bent inwardly, as indicated by'76, so as to overlie the shield-66.
Since this apparatus'requires fuel to be under pressure, any suitable pressurizing'means maybe employed and to this end a small priming pump 80 (Figs. l 3) may advantageously be used. This pump comprises a cylindri- 7 cell sleeve 81 which extends downwardly through suite able openings formed in the shield 66 and tank the upper endof the tube 81 having a sliding fit within a collar .82 which; extends into the tank. The collar '82 from the nozzle 46 and readily mixed with air drawn in through the openings 56,, Both 'the,.inner;and outer 7 members '52 and:58 'Fbecomeheated' and transmijteenough.
heat to the tank 4 to'maintain the fuel thereinv under sutficient'pressureto'insure continuous feedingo'f the fuel to the burner assembly. In order to shut off the burner it is merely necessary to turn the handle 30 to closed position, thereby cutting off the fuel supply.
. Since an adequate amount of air is drawn inthrough the spider-like base 1 and the. depending skirt 68,..com-
is 'brazed- 'orotherwise. suitably secured to the tank 41 and its upper end is threaded to receive a cap '84 which carriea sealing ring $5. The cap 84- has a sliding fit about the "upper end of thejsleeve, and the sleeve, cap
and parts carried thereby may be removed as a unit when the tank is to; be replenished because of the friction f 7 between the sleeve 81 and piston ring 90.
"A tubular piston rod 86 loosely passes,through*the upper end of the cap and its lower end carries apiston 88 which may be of conventionaldesign and construe tion, being provided with the usual piston ring 90 anda floating flap valve 91 which opens the. air intakein the} piston during the return orupstroke, but closes this opening during the pressurestroke. The lowerJend of :thecylinder 81-"is provided with a plug 92 which is brazed or otherwise suitably secured theretoandabushmess isthreaded into the'end of the plug.9 2; theplug 92 and bushing 93ibeing provided with registering'jinlet openings 94mm 95, respectiyely, The inlet opening 94 v isclosed by a springJoaded valve 96Yseated on the lower end of fthe bushing 93, theloading of the valve 96 being such as to maintain it-in closed position during the return oi-upstroke of the piston, but, insufficient to hold itelosed duringthe pressnre stroke.
plate combustion is assured. and the v, fuel-burnslwith a. blueflame. Thelegs 76 hold the cooking utensil i at ,a, level sufiiciently above the. burner assembly to prevent inte fiference with the eificient burning of the fuel. and hence the generation of carbon monoxide and the for-ma tion of semis-prevented. 1
available in all formsof transportation vehicles it "is unnecessary to-carrya supply of a specially prepared fuel such as -solidifid alcohol: I -While we have shown. andfdescribed one ldesira'ble em'bodiment of the invention it is to bejunderstood that this disclosure is for the purpose ofiillustration and that various fihanges and; modifications may bernadewithout set forth in theappendedclaims;
departing fro'mthe spirit and scope of the invention absence We claim:
1. VA cooking stove comprising a fixed, shallow annular-shaped fuel tank having a vertical axis, a feed line extending from the bottom of said tank radially inwardly, a valve coaxially disposed relative to said tank and positioned between parallel planes passing through the upper and lower boundaries of said tank, the lower part of said valve being connected with said feed line, a burner assembly mounted on the upper part of said valve, an annular shield including a generally fiat annular horizontal portion coaxial of and disposed above the. tank in closely spaced relation thereto, the shield including a central annular portion coaxial of the tank depending from said horizontal portion into the region between the tank and the burner and extending around the burner, and means for supporting a utensil above the burner with the flat portion of the shield intermediate the utensil sup-' porting means and the tank.
2. A stove according to claim 1 having the generally fiat portion of the shield above the annular tank substantially coextensive with the outside configuration of said tank.
3. A stove according to claim 1 wherein the generally flat portion of the shield is supported in spaced relation on the tank by connecting means extending therebetween and wherein the utensil-supporting means are retractibly associated with said connecting means.
, 4. A stove according to claim 1 wherein the burner portion comprises an outwardly-flaring cup-shaped eon- Y figurationand wherein the depending portion of the shield includes a frusto-conical portion disposed in substantially equi-spaced relation to said cup-shaped portion f of the burner.
5. A stove according to claim 1 wherein the depend ing central portion of the shield extends downwardly between the burner and the surrounding tank to a pointlower than the mid-height of the tank.
6. A stove according to claim 1 wherein the utensil is adapted to be supported in closely spaced relation above the burner and at a distance above the top of the tank approximating the separation between the upper and lower boundaries of said tank.
References Cited in the tile of this patent UNITED STATES PATENTS