US2544217A - Blowtorch - Google Patents

Description

s. c. BRoDY BLOWTORCH 5 Sheets-Sheet l Filed April 28, 1949 QN/0 a R. y n N 0 m1@ vm n HJ C /4 m 0 d /Q z, wr ...u D 1 H Q o f a M f4 y z 5 4 M. 4 H4 M m Z m A! /f/ MH I 7 /f0//| H m m 9,5/ f .w ,i f M J k am .Il /f 5 4 M 4 k 0/ 2J March 6, 1951 s. c. BRODY 2,544,217

BLOWTORCH Filed April 2B, 1949 `3 Sheets-Sheet 2 March 6, 1951 Fiied April 28,

s. c. BRODY 2,544,217

BLOWTORCH 1949 3 Sheets-'Sheet 3 IN V EN TOR.

Patented Mar. 6, 1951 UNITED STATES PATENT OFFICE BLOWTORCH Samuel C. Brody, Cambridge, Mass.

Application April 28, 1949, Serial No. 90,181

14 Claims. l

This invention relates generally to automatic blow torches of the self-generating type, and particularly to a torch of this type which produces a blast flame of uniformly great heat intensity.

An object of this invention is to provide a torch of the self generating type in which a high degree of heat transfer is obtained between the combustion tube and the torch casing containing the fuel for the purpose of realizing the optimum vaporization of the raw fuel and the consequent high fuel vapor pressures.

An additional object of this invention is to provide a self generating torch in which the danger of explosion, resulting from the contact of cool raw fuel with the intensely heated portions of the torch casing, is completely eliminated.

It is a further object of this invention to provide a blow torch of the self generating type having a positive control of the fiow of fuel vapors to the burner nozzle for the purpose of regulating the size and intensity of the blast flame and also for the complete extinguishment of the flame.

Still another object of this invention is to provide a self-generating torch in which burning and scorching of the wick is completely eliminated, obviating the difficult replacement of scorched wicks and resulting in trouble free operation of the burner nozzle due to the absence of clogging by charred portions of the wick.

A further purpose of this invention is to provide a self-generating torch in which there is direct heat transfer betweenvthe combustion tube and the fuel containing casing and particularly the top wall thereof, whereby continuous heating of the fuel in the casing is achieved producing rapid vaporization thereof and the concomitant build-up of uniformly high pressures increasing with continued operation of the torch. The heating of the fuel and the super-heating of the vapor thereof being fostered by the construction of the top wall of the casing and the placement of the barrier in Contact therewith.

In order that the many advantages of my invention may be more fully understood and appreciated, reference is made to the accompanying specification and drawings, wherein I describe- Figure 7 is a detail fragmentary sectional View of a portion of the device shown in Figure 3 illustrating a possible positioning of the elements thereof,

Figure 8 is a top plan view of a modification of my invention,

Figure 9 is a fragmentary side elevation partly in section taken on the line 9-9 of Figure 8, and

Figure 10 is a fragmentary sectional view taken on the line IIJ-II) of Figure 9.

Referring to Figures 1 through 5 of the drawings, I have there illustrated a preferred embodiment of my invention. The blow torch includes a fuel reservoir or casing I0 having a cylindrical side wall II. The bottom of the side wall II is formed with internal threads for removably receiving the bottom closure I2 which is in the shape of a disc and has threads formed on the perimeter thereof for engaging in the bottom of the side wall. The top end of the side wall is sealed by a circular stepped top wall I3 which is formed with a raised horizontal portion Ill, a depressed horizontal portion I5, and a connecting vertical portion I6. The raised portion I4 is positioned flush with the top end of the side Wall II and the depressed portion I5 extends downwardly into the casing I0 to provide, with the side wall I I, a priming chamber or well Il. The edges of the top wall I 3 are welded, brazed, or soldered to the side wall II to effectively seal the interior of the casing I Il. A horizontally disposed pressure generating tube and valve stem housing I8 extends diametrically across the top of the casing IIJ, positioned ybelow the raised top wall portion I9 and 20 are welded, brazed, or soldered to the.

side Wall II at the intersection thereof in order ami/1,2 17

3 to make the casing I both liquid and gas tight. An opening 2I is formed in the bottom of the tube I8 within that portion which is contained by the raised top wall portion I4, the vertical portion I6, and the side wall II. The end I9 of the valve stem housing and pressure generating tube I8 is threaded to receive a gland nut 22 Which with the packing 2S seals this end of the tube I8. A bushing 24 welded to the side wall I I surrounds the end 2i! of the tube I8 and is flush with the forward end thereof 'to provide a relatively large seat for the nozzle member 25. The nozzle member 25 has a body portion 28 and oppositely projecting threaded lugs 21 and 28. A longitudinal bore 29 extends through the nozzle member 25 and has a reduced orifice 38 substantially in the center thereof. The end of the bore 295 in the lug 28 is countersunk to provide a valve seat 3|. The lug 28 of the nozzle member 25 is threadedly received by the end 2 8I of the tube I Swithrthenozzle iember body portion 25 abutting againstmthe bushing 24 and the end of thetube I8 to provide intimate contact for the transfer of heat.` ,A combustion tube 32, having a thickenedwall portion 33 is threadedly mounted on thelug 21 of the nozzle member 25Vwith the thickened portion 33 abutting against the nozzle ,member body 25 tonprovidera large contact area for heat transfer. The pressure generating rtube and valve stem housing I8 has a thickened internally threaded wall portion 34, A valvemember 35 is positioned in thetube I8 and has a valve portion 35 for seating against the valve seat 3l, a valve stem 31 of lesser diameterthan the interior of the tube I8, and a threaded enlarged diameter portion 38 for engagement with thethickened wallportion 34, whereby rotation of the valve stem,31 will cause movement of the Valve portion 36 towards or awayfromuthe valve seat 3l for seating and unseating respectively. The valvestem 31 projects rearwardly through the packing 23 and glandv nut 22 and has an operatingknob 89 secured thereon. rlhe outer end of the combustion tube 32 may be formed with thread segments 4i) on the outer surface thereof for `the attachment of a soldering tip 48e as ,shown in Figure 6. As best seen in Figure 3, a barrier 4|-, which is of disc shape to tightly conform to the interior contours of the side wall II, is disposed inthe casing I0 with the top surface of the barrier 4I pressed against the underside of the depressed top wall portion I5. A spring member or prop 42 may be interposed between the barrier 4I and the bottom closure I2 for the purpose of constantly urging the barrier 4I against the top wall portion I5. The barrier is formed of a material such as felt or the like which is gas permeable and yet substantially blocks the passage of liquid fuel therethrough. A capillary wick 43 is positioned in the fuel casing IE! and extends upwardly through the passageway 44 formed inthe barrier 4I. The top end of the wick member 43 is knotted as at 45 to prevent its slipping down into the bottom of the fuel casing. The passageway d4 underlies the opening 2! formed in the pressure generating tube, and the knot 45 may be spaced from the opening 2l as shown in Figure 3, or in contact with the opening ZI substantially filling the same, as seen in Figure 7. In either case the knot 45 will be positioned in the gas chamber 4S formed by the top of the barrier 4 I, the top wall portions I4 and I6, and the side wall I I. As seen in Figure 6 the spring 42 may be dispensed with and the barrier 4I maintained in place against the top wall portion I merely bythe frictional engage- 4 ment of the side edges of the barrier with the side Wall II.

In Figures 8 through 10, I have disclosed a modification of the blow torch above described. In this modification of my invention, a shortened pressure generating tube and valve stem casing 41 is provided. The tube or casing 41 extends through the gas chamber 46, projecting rearwardly through the side wall II and forwardly through the` vertical portion IG of the top wall. The forwardly projecting end 48 of the tube or casing 41 is cut short just beyond the wall portion I 6. A bushing 49 surrounds the end 48 flush therewith and is welded, brazed or soldered to the end 48 and a threaded outer lug 52 for carrying 'a combustion tube 32 is positioned against the bushing 49. The combustion tube 32 is mounted on the nozzle member* lug 52 and `ex tends forwardly through the opening 53 formed in the's'ide wall IV'I.A Asr can be ,readily seen in Figure 9, a substantial length of the'combustion tube lies within the priming chamber I1 and therefore overlies the` top wallhportion I5. lThe nozzle member '58 is formed with a bore 54 extending longitudinally therethrough having a reduced diameter center portion orifice 55 and an inwardly inclined shoulder 56 between the bore 54 and the orice portion 55 to provide a valve seat. As is apparent, the valve stem 31 is shortened so as to provide for the desired seating of the4 valve portion 36 on the valve seat 56.

The operation of my device is as follows; Fuel is admitted to the interior of the casing I0 by inverting the torch and removing the bottom closure I2, the valve 36 being seated to prevent leakage of the fuel. The fuel may be alcohol Vor any like substance. After the desired quantity of fuel has been poured into the casing or reservoir I0, the closure lI2 is replaced and the torch placed Vin an upright position, A quantity of fuel is then poured into the priming chamber or well I1 and ignited. Inthe embodiment of my invention illustrated by'Figures 1 through 5, the burning priming charge will intensely heat the portion of the tube or casing I8 overlying the top wall portion l5, the top wall portion I5, the top wall portion I6, and the upper end 'of the side wall II. The heated tube or casing I8 will transmit heat to the gas chamber 45 and begin the vaporization of the fuel rising in the wick 43. 'I'he vaporizedfuel will enter the tube I8 through the opening 2| and will be further heated and pressurized as it passes therealong. When the top of the casing is suiiiciently heated 'so that substantial fuel pressure is obtained, the valve 36 is cracked open to allow the vapors to pass through the nozzle orifice 38 into the combustion tube 32. These vapors-are then ignited and the normal functioning'o'f the -torchhas commenced. During this normal functioning', heat from -the combustion tube 32. is Conducted back through the nozzle member 25 to the bushing 24 and the tube IBand through these two latter members directly to the side wall and the top wall portion I6. Ihe top wall portions I4 and E5 will be heated by conduction from the portion I6 and the tube I8. It `is* apparent, therefore, that the top wall I3 and the side wall I'I will be progressively intensely heated asA the torch is operated. Fuel rising through the wick 43 will be vaporized as it reaches the knot 45 since the knot -45 is located in lthe gas chamber which is heated by the top wall portions I4 and I6 and the side wall II. As shown in Figure '7, the knot itself may be positioned against the opening 2l in contact with the tube I8 to achieve intense heating of the knot. The barrier 4I, as had been noted, is placed against the under side of the top wall portion i5 and tightly ts against the side wall II, which results in the top surface and the side edges of the barrier being intensely heated. This heating of the barrier provides positive assurance that no liquid fuel will be allowed to come in contact with the heated top wall I3 since it creates a physical and thermal barrier to such contact. The thermal barrier is best explained by assuming that small quantities of the liquid fuel did infiltrate throughV the barrier. As the liquid fuel passed upwardly it would contact the heated portions of the barrier and be Vaporized thereby, so that by the time the intensely heated top wall was reached the entire fuel would be vaporized. This makes it possible to usemy torch in any position without the danger of explosion normally attending the contact of liquid fuel with a heated surface. Since fuel which passes through the barrier is vaporized during such transit, the heated barrier also contributes to the vaporization of fuel and increases the pressure at the nozzle thereby increasing the intensity of the flame. Rotation of the valve stem 3l by means of the knob 39 will control the amount of fuel vapor -passing through the orifice te and thus control the size of the flame in the combustion tube. By completely closing the Valve 36 on the seat 3I, the flame can be safely extinguished.

In the modification of my invention illustrated by Figures 8 through 10 of the drawings, the depressed top wall portion VI5 is directly heated by flames ejected from the combustion air holes commonly formed in the combustion tube. Heat will be carried back to the vertical top wall portion I6 through the nozzle member 50 and the bushing 49 abutting that wall portion. Heat also will be transferred directly to the pressure generating tube and valve stem casing lil from the combustion tube thus effecting the intense heating of the tube 4l and the gas chamber 45. The side wall I I will be heated by the combustion tube 32 where it passes therethrough, and by the tube lll where it projects rearwardly through the side wall I I: The side edges and the top surface of the barrier 4I will therefore be heated in amanner similar to that described with respect to the first embodiment of my invention so as to constitute the barrier both a physical and thermal barrier to the contact of liquid fuel with the intensely heated top wall I3.

The foregoing description and the drawings disclose preferred embodiments of my invention. However, it is apparent that modifications in construction andarrangement may be resorted to without departing from the scope of my invention which is defined in the appended claims.

What I claim is:

y 1. A vblow torch comprising a fuel reservoir including a cylindrical side wall and a stepped top wall.A forming a depressed portion and a raised portion, a horizontally extending combined valve housing and'pressure generating tube member disposed adjacent the top end of said side wall `and having a portion thereof underlying said raised portion in direct heat lexchange relation to said top wall, and a gas permeable barrier disposed in said fuel reservoir with the top surface thereofl against said depressed'porheat from said tube member will be transferred through said top wall to said barrier for constituting said barrier a thermal and physical barrier to contact of liquid fuel with said top wall, and whereby said top surface and said raised portion will coact to define a gas chamber.

2. A blow torch comprising a fuel reservoir including a cylindrical side wall and a stepped top wall forming a depressed portion and a raised portion, a horizontally extending combined valve housing and pressure generating tube member disposed adjacent the top end of said side wall and having a portion thereof underlying said raised portion in direct heat exchange relation to said top wall, a gas admitting opening formed in said underlying portion, a gas permeable barrier disposed in said fuel reservoir with the top surface thereof against said depressed portion, said raised portion and said top surface coacting to define a gas chamber and a wick member extending upwardly through said barrier and having an end thereof terminating in said gas chamber, whereby when said torch is in operation, heat from said combined member will be transferred to said top wall for heating of said barrier, thereby constituting said barrier a thermal and physical barrier to contact of liquid fuel with said top wall, and for heating said gas chamber, thereby effecting vaporization of fuel rising in said wick member.

3. A blow torch comprising a fuel reservoir including a cylindrical side wall and a stepped top wall forming a depressed portion disposed downwardly from the top end of said side wall and aA raised portion disposed iiush with said top end, a gas permeable barrier in said fuel reservoir having the top surface thereof positioned against said depressed portion, said top surface of said barrier and said raised portion coacting to provide a gas chamber, a horizontally extending combined valve housing and pressure generating tube member having a portion thereof disposed within and extending across said gas chamber in direct heat exchange relation to said top wall, at least one end of said combined member extending outwardly through said cylindrical side wall, a gas admitting means formed in said combined member portion disposed within said gas chamber, and a wick member in said fuel reservoir extending upwardly through said barrier and havingY an end thereof disposed in said gas chamber adjacent to said gas admitting means, whereby when said torch is in operation, heat from said combined member will be transferred to said top wall and said side wall for heating said barrier and said gas chamber, thereby constituting said barrier a thermal as well as physical barrier to the contact of liquid fuell with said top wall and effecting the vaporization of fuel rising in said wick member.

4. A blow torch comprising a fuel reservoir including a cylindrical side wall and a stepped top wall forming a depressed portion disposed downwardly from the top end of said side wall to provide a priming chamber, and a raised por- 'heat exchange relation to said top wail, at least one end of said combined member extending outwardly through said side wall, nozzle means carried by one end of said combined member, a combustion tube mounted 'on said nozzle member in direct heat exchange relation to said side Wall, and said combined member, gas admitting means formed in said combined member portion disposed in said gas chamber, and a wick member in said fuel reservoir extending upwardly through said barrier and having an end thereof disposed in said gas chamber adjacent to said gas admitting means, whereby when said torch is in operation, heat from said combustion tube will be transferred through said side wall and said combined member to said top wall and said gas chamber for heating said barrier and said wick end, thereby constituting said barrier a thermal as well asa physical barrier to the contact of liquid fuel with said top Wall, and effecting the vaporization of fuel rising in said wick member.

5. A blow torch comprising a fuel reservoir including a cylindrical side wall and a stepped top wall forming a depressed portion disposed downwardly from the top end of said side wall to provide a priming chamber, and a raised portion, a gas permeable barrier in said fuel reservoir having the top surface thereof positioned against said depressed portion, said top surface of said barrier and said raised portion coacting to denne a gas chamber, a horizontally extending combined valve housing and pressure generating tube member having a portion thereof disposed within and extending across said gas chamber in direct heat exchange relation to said top wall, at least one end of said combined member extending outwardly through said side wall, nozzle means carried by one end of said combined member having a valve seat formed therein, valve means threadedly carried in said combined member and adapted to engage said valve seat for regulating the passage of vapor-ized fuel through said nozzle member, a combustion tube mounted on said nozzle member in direct heat exchange relation to said side wall and said combined member, gas admitting means formed in said combined member portion disposed within said gas chamber, and a wick member in said fuel reservoir extending upwardly through said barrier and having an end thereof terminating in said gas chamber adjacent to said gas admitting means, whereby when said torch .is 'in operation, heat from said combustion tube will be transferred through said side wall and said cornbined member to said top wall and said gas chamber for heating said barrier and said wick end, thereby constituting .said barrier `a thermal as well as a physical barrier to the contact -of liquid fuel with said top wall, and effecting `the vaporization of fuel rising in said wick member.

6. A blow torch comprising a fuel reservoir including a cylindrical side wall and a stepped top wall forming a raised portion and a depressed portion, a combined valve housing and pressure generating tube extending transversely across -the top end of said side wall in direct 'heat exchange relation to said top wall, said tube overlying said depressed portion for a substantial portion of the length thereof and underlying said raised portion for another substantial portion of the length thereof, and a gaspermeable barrier disposed in said fuel reservoir with the top surface thereof against said depressed portion and the side edges thereof sealingly'engaging said 'cylinvdrioal side wall, a portion of said top surface 8, and said raised portion coacting to denne a gas chamber, whereby when said torch is in operation, heat from said tube will be transferred through said top wall to heat said barrier thereby constituting said .barrier a thermal as well as a physical barrier to the contact of liquid fuel with said top wall, and whereby said underlying portion of said tube will heat said gas chamber thereby vaporizing fuel rising thereto.

'7. A blow torch comprising a fuel reservoir including a cylindrical side wall and a stepped top wall forming a raised portion and a depressed portion, a gas permeable barrier in said fuel reservoir with the top surface thereof positioned against said depressed portion and the side edges thereof sealingly engaging said cylindrical side wall, a portion of said top surface coacting with said raised portion to define a gas chamber, a combined valve housing and pressure generating tube extending transversely across the top end of said side wall in direct heat exchange relation to said top wall, a portion of the length of said tube being disposed within said gas chamber and another portion of the length of said tube overlying said depressed portion, whereby heat from said tube will be transferred through said top wall to heat said barrier thereby constituting said barrier a thermal as well as a physical barrier to the Contact of liquid fuel with said top wall, and whereby said portion of said tube disposed within said gas chamber will effect the heating thereof thereby vaporizing the fuel rising thereto.

8. A blow torch comprising a fuel reservoir including a cylindrical side wall and a stepped top wall form-ing a raised portion and a depressed portion, a gas permeable barrier in said fuel reservoir with the top surface thereof positioned against said depressed portion and the side edges thereof sealingly engaging said cylindrical side wall, a portionvof said top surface coacting with said raised portion to define a `gas chamber, la transversely extending combined valve housing and pressure generating tube disposed for a portion of the length thereof within said gas chamber and `overlying said depressed portion in heat exchange relation thereto, the opposite ends of said tube extending outwardly through said side wall, a nozzle member carried by one of said ends in direct heat exchange relation to said side wall, a combustion tube mounted on said nozzle member, 'gas admitting means formed in said tube portion disposed within said gas chamber, and a wick member disposed in said fuel reservoir extending upwardly `vthrough said barrier and having an end thereof terminating in said gas chamber, whereby when said torch is in operation, heat from said `combustion tube will be transferred through said nozzle member to said side wall and through said tube to said top wall and said gas chamber for heating said barrier and said wick end thereby constituting said barrier a thermal as -well as a physical barrier to the contact of liquid fuel with said top wall, and effecting the vaporization of fuel rising in said wick.

9. A blow torch comprising a fuel reservoir including a cylindrical side wall and a stepped top wall sealing the top end thereof, said stepped top wall forming a raised portion and a depressed portion, a gas permeable barrier in said fuel reservoir having the top surface thereof positioned against said depressed portion and the side edges thereof sealingly engaging said side wall, a 'portion of said top surface -coacting with said raised portion to define algas chamber, a combined valve housing and pressure generating tube member extending transversely across the top of said side wall in direct heat exchange relation to said top wall, a portion of said combined member being disposed within said gas chamber and another portion of the length thereofoverlying said depressed portion, the opposite ends of said combined member extending outwardly through said side wall, a nozzle member carried by one of said ends in direct heat exchange relation to said side wall, a valve seat formed in said nozzle member, a combustion tube mounted on said nozzle member, gas admitting means formed in said portion `of said combined member disposed within said gas chamber, valve means carried by said combined member adapted to engage said valve seat for controlling the flow of fuel vapor to said combustion tube, and a wick member in said fuel reservoir extending upwardly through said barrier and having an end thereof terminating within said gas chamber, whereby when said torchy is in operation, heat from said combustion tube will be transferred through said nozzle member to said side wall and through said combined member to said top wall and said gas chamber for heating said barrier and said wick end, thereby constituting said barrier a thermal as well as a physical barrier to the contact of liquid fuel with said top wall, and effecting the vaporization of fuel rising in said wick.

10. A blow torch comprising a fuel reservoir including a cylindrical side wall and a stepped top wall forming a raised portion, a depressed portion and a vertically extending connecting portion, a gas permeable barrier in said fuel reser- Voir with the top surface thereof positioned against said depressed portion and the side edges thereof sealingly engaging said side wall, a horizontally disposed combined valve housing and pressure generating tube member underlying said raised portion and having an end thereof extending through said connecting portion, a nozzle member carried by said end in direct heat exchange relation to said connecting member, a combustion tube mounted on said nozzle member and extending horizontally therefrom, said combustion tube overlying said depressed portion in heat exchange relation thereto and extending out.. wardly through said side wall, whereby when said torch is in operation, heat from said combustion tube will be transferred through said nozzle member to said top wall, directly through said top wall, and through said side wall for heating of said barrier, thereby constituting said barrier a thermal as Well as a physical barrier to the contact of liquid fuel with said top wall.

11. A blow torch comprising a fuel reservoir including a cylindrical side wall and a top wall forming a raised portion, a depressed portion, and a vertically extending connecting portion, a gas permeable barrier in said fuel reservoir with the top surface thereof positioned against said top Wall and the side edges thereof sealingly engaging said side wall, a portion of said top surface coacting with said raised portion to define a gas chamber, a combined Valve housing and pressure generating tube member extending horizontally across said gas chamber and having the opposite ends thereof extending through said side wall and said connecting portion, a combustion tube mounted on said nozzle member overlying said depressed portion in heat exchange relation thereto, said combustion tube extending outwardly through said side wall, gas admitting means formed in said comb-ined member cornmunicating with said gas chamber, and a Wick -member in said fuel reservoir extending upwardly through said barrier and having an end thereof terminating in said gas chamber, whereby when said. torch is in operation, heat from said combustion tube Will be transferred directly to -said"s'ide wall and said top wall and through said nozzle member to said combined member and e end.

12. A blow torch comprising a fuel reservoir including a cylindrical side wall and a stepped top wall forming a raised portion, a depressed portion and a connecting portion, a gas permeable barrier in said fuel reservoir with the top surface thereof positioned against said depressed portion and the "side edges thereof sealingly 'engaging said side wall, a portion of said surface, said raised portion, and said connecting portion coacting .to define a gas chamber, a combined valve housing and pressure generating tube dis posed in said gas chamber and extending horizontally thereacross, one end of said combined member extending outwardly through said connecting portion and the other end thereof extending outwardly through said side wall, a nozzle member carried by said one end in direct heat exchange relation to said connecting portion, a combustion tube overlying said depressed portion having one end thereof mounted on said nozzle member and the other end thereof extending outwardly through said side Wall, a valve seat formed in said nozzle member, gas admitting means formed in said combined member comm-unicating With said gas chamber, Valve means carried by said combined member adapted to engage said seat for regulating the flow of vaporized fuel to said combustion tube, and a Wick member in said fuel reservoir extending upwardly through said barrier and having an end thereof terminating in said gas chamber, whereby when said torch is in operation, heat from said combustion tube Will be transferred through said side wall, top Wall, nozzle member and combined member for heating said barrier and said gas chamber, thereby constituting said, barrier a thermal as well as a physical barrier to the contact of liquid fuel With said top Wall, and eifecting the vaporization of fuel rising to said Wick end.

13. A blow torch comprising a fuel reservoir including a side wall and a stepped top wall forming a depressed portion and a raised portion, a gas permeable barrier disposed in said fuel reservoir with the side edges of said barrier sealingly engaging said side wall and a substantial portion of the top surface of said barrier bearing against said depressed portion of said top wall, the remainder of said top surface and said raised portion of said top Wall defining a gas chamber, pressure generating tube member extending transversely across said side Wall adjacent the top end of the` latter and disposed in direct heat exchange relation to said top Wall, and means communicating said tube member with said gas chamber, whereby when said torch is in operation, heat from said tube member will be transferred through said top wall to said gas chamber and to said top surface of the barrier for constituting the latter a physical and thermal barrier to the contact of liquid fuel with said top wall.

lll. A blow torch comprising a fuel reservoir 'Il including a side Wall and a stepped top Wall forming a depressed portion and a raised portion, a gas permeable barrier disposed in said reservoir with the side edges of said barrier sealingly engaging said side wall and a substantial portion of the top surface of said barrier bearing against said depressed portion of said top wall, the remainder of said top surface and said raised portion of said top Wall dening a gas chamber, a combined valve housing and pressure generating tube member extending transversely across said side wall adjacent the top end of the latter and disposed in direct heat exchange relation to said top Wall, and means communicating said tube member with said gas chamber, whereby when said torch is in operation, heat from said tube member will be transferred through said top wall to said barrier for constituting the latter a physical and thermal barrier to the contact of liquid fuel with said top Wall, and to said gas chamber,

for pre-heatirlf,r the gaseous fuel therein prior to its entrance into the combined tube member.

SAMUEL C. BRODY.

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

UNITED STATES PATENTS

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