US3011541A - Flame thrower - Google Patents

Description

Dec. 5, 1961 Filed Sept. 5, 1951 H. soRENsl-:N 3,011,541

FLAME THROWER -3 sheets-sheet 1 #rra/Me H. SORENSEN FLAME THROWER Dec. 5, 1961 5 Sheets-SheeiI 2 Filed Sept. 5 1951 MQ NSN wmww my -mwN 3,011,541 FLAME THROWER Henry Sorensen, Ralston, Sufleld, Alberta, Canada, as-

signor to Her Majesty the Queen in right of Canada as represented by the Minister of Defence Filed Sept. 5, 1951, Ser. No. 245,233 Claims priority, application Canada Aug. 3, 1951 12 Claims. (Cl. 158-28) The present invention relates to a ilam-e thrower and more particularly to a llame thrower for use as a weopon to project a burning rod of llame fuel upon a target.

The flame thrower currently used by the Canadian Army is designated the Wasp llame thrower and is described in detail in Canadian Army Flame Training Manual, Flame Thrower Transportable, No. 2 Mark 2C (Wasp 2C) 1950, the principle of operation thereof being that thickened llame fuel is supplied under pressure to the llame thrower barrel which is provided at its forward end with a nozzle closed by a pintle valve formed on the front of a pintle running longitudinally through the barrel. The pintle is hollow and is for-med in two sections which are capable of limited relative longitudinal movement with respect to each other. The rearmost section of the pintle is fixed to the body of the barrel and a supply of gas under pressure passes through the rear section of pintle and forces the front section thereof to a forward position where the pintle valve shuts ott the nozzle at the front of the barrel of the flame thrower. To operate the gun the gas pressure is released from the rea-r section of pintle and the pressure of the flame fuel forces the forward section of the pintle to the rear, opening the nozzle and allowing the flame fuel to be projected as a rod of fuel under the intluence of its own pressure. The rod of fuel is ignited by suitable ignition means timed to actuate upon opening of the pintle valve, and the stream of flaming fuel is cut off by restoring the gasV pressure in the rear section of the pintle, forcing the pintle valve forward to close the nozzle of the flame thrower barrel.

lThe yarrangement described in general terms above has proved fairly satisfactory in service but has a number of important disadvantages. It the rst place, while the principle of operation is fairly simple, the pintle formed in two sections in the manner described, and its associated mounting, required a considerable number of accurately machined parts, making production of the ilame thrower both costly, and time and labour consuming. In addition, of course, the maintenance of such weapons in action has required highly trained personnel.

More important from a tactical point of View, the Wasp flame gun has a limited range, and the rapidity of its operation is not as great `as might be desired.

The presen-t invention has, as one of its principal objects, the provision of a llame gun of simplified design which can be produced with a minimum of production time and cost, `and which requires -a minimum of maintenance and training of personnel for its operation.

It is also the object of this invention to provide a llame gun having an increased range and rapidity v of operation. I v

Further objects and advantages of the invention will become apparent as the specilication proceeds.-

Broadly speaking, the foregoing objects of the invention are achieved by forming the pintle in such ya mannerV that it functions as a single unit and providing an air cylinder mounted yon the body of the flame thrower at .the rear thereof, into which the rear portion of the pintle, which which is formed as a piston to tit said cylinder, extends, so that the entire pintle moves as a single unit to control the ilow of flame fuel. The whole structure of thepintle assembly is 1accordingly greatly simplied and the added advantage is achieved that the pintle itself may be made i td States Patent considerably slenderer to provide much better flow characteristics in the barrel of the gun, and thus a greater range of projection has been achieved.

Gas under pressure to control the movement of the pintle valve may be supplied and controlled in a number of manner, but it is preferred to supply andl control it by means of a control block assembly in'which a control spindle may be slid longitudinally of its axis simultaneously to establish communication between the cylinder and the atmosphere, and to cut off communication between a supply of gas under pressure and the interior of the cylinder. Such an arrangement lends itself readily to coupling with a second longitudinally slidable spindle within the control block, which is arranged to be slid longitudinally to operate an electric micro-switch for actuating the ignition means, and a petrol control valve controlling flow of petrol to the ignition means, in which arrangement the two -spindles may be simutaneously operated, and adjusted to provide for proper timing and sequence of the operations, whereby, the assembly being all connected to a single trigger, all operations of the llame thrower required to tire a shot will take place on pulling said trigger and will cease upon release of said trigger.

The invention will be more fully appreciated from the following detailed description of an embodiment thereof inV which reference is had to the accompanying drawings wherein:

FIGURE 1 is a perspective view of a llame thrower according to the invention, fully assembled and ready for action,

FIGURE 2 is a sectional view takenalong the longitudinal axis of the gun, showing the pintle valve in closed position,

FIGURE 3 is an enlarged detail partly in section, taken along the plane 3--31y in FIGURE 1,

FIGURE 4 is a horizontal section taken through the longitudinal axis of the gas cylinder at the rear of the flame thrower barrel, illustrating the position of the pintle piston when the pintle valve is in the closed position and illustrating the arrangement of the gas control valve,

FIGURE 5 is a top view partly in section of the ignition means used to ignite the main ilow of llame fuel when the gun is fired,

FIGURE 6 is a perspective detail of the petrol nozzle, the section being taken along the plane 6-6 in FIG- URE 7, v

FIGURE 7 is a front view of the petrol nozzle, and

FIGURE 8 is a perspective view partly cutaway of the atomizer nozzle in the ignition means. Y

Referring more particularly to the drawings, a flame thrower according to the inventionl is generally of the same shape and external appearance as previous llame throwers and comprises the barrel 10 provided with the conical nozzle component 12 forming a valve seat 13 at the front end thereof and the nozzle tip 14,

The barrel 10 is screw-threaded and connects at 15 to the gun body lvwhich is formed-with the hollow elbow 17 of generally the same internal diameteras the barrel 10 and screw threaded as at 18 for connection' in conabuts Aagainst the rearfface of a sealingring '24 and sealer 24a and is secured in position by the securing ring 2K5 which is secured byA screw-threads around Vthe Vrear 3 of the portion 19 as will be best observed from FIGURE 4. Provision is made by means of the radial holes 26, the annular space 27 and the borings 28 for communication between the space 23 in the front end of the interior of the cylinder block 22 and the atmosphere.

Extending axially lengthwise of the barrel is the pintle 29 which is thickened over the forward portion 30 thereof to provide a conical portion 31 at the front end which is of larger diameter at its base than the diameter of the nozzle tip 14, so that the rear portion 32 of the conical portion 31, when pressed forward, will seat against the forward portion 13 of the conical nozzle component 12 to form the pintle valve. Mounted upon the portion 30 of the pintle 29 and uniformly spaced about the circumference thereof are the pintle guide vanes 33. These are generally three in number, spaced at 120 to each other and are designed to keep the pintle 29 in axial alignment with the barrel 10` and associated nozzle parts 12 and `14. At the rear, pintle 29 is screw-threaded as at 34 to the pintle piston 35 which lits slidably within the boring 2Q and is provided with the enlarged head 36 at its rearward end which forms a piston head slidable within the cylinder block 22. The head 36 is provided with a suitable sealer 37 secured to its rearward face by the securing screw 37a. Thus it will be observed that the pintle 29 and its connected parts are free to reciprocate to a limited extent within the barrel 10, the forward extent of such reciprccation being limited by the seating of the pintle valve in the valve seat formed by the valve seat portion 13 of the conical nozzle 12; a small lfree space is allowed for between piston head 36 and the ring 24, compressing the sealer 24a. The rearward extent of reciprocation of the pintle is limited by the end 38 of the gas cylinder 39 formed in the cylinder block 22. The rearward motion is usually further limited by placing within the gas cylinder 39 two hard fibre recoil washers 39a.

The body 16 is mounted upon a suitable mounting, which may for instance be on a weapon carrier or other vehicle, by being pivoted by pivot bolts 4i) and 40a to the arms 41 of the stirrup 42 which is pivoted at its other end upon the pin 43 which is secured upon a securing bar 44 rwhich in turn is secured by means of the slots 4S and securing screws 46 to a supporting structure. 'lfhus the gun is pivotable in a substantially horizontal plane about the axis of the pin 43 and in a substantially vertical plane about the pivot bolts 40 and 40a.

The cylinder block 22 fits against a suitably curved side 47 of the control block 48. A passageway 49 is formed in the cylinder block 22 and the control block 48 is provided with a similar passageway 5t) which is so arranged as to register with the passage 49 when control block 48 and cylinder block 22 are secured in position by means of the base plate S1 and the securing bolts 52, 52a, 53, 53a, 54, 55 and 56 which lit in suitable borings in the base plate, cylinder block and control block. A sealing ring is inserted =where passage ways 49 and 50 join.

As will best be observed from FIGURE 4, the passage Sti in the control block widens out to form a valve cylinder 57 which is disposed substantially parallel to the axis of the gun. The control block 4S is tapped at one side thereof at 58 to secure the hollow plug 59 which connects to a supply of gas under pressure (not shown) by means of a flexible hose 60. The gas inlet port 58a affords communication between the interior of the hollow plug 59 and the interior of the valve cylinder Ibore 57. Slidably tted within the cylinder bore 57 is the valve body 61 which, it will be observed, is centrally bored with the passage 62 but is closed at its forward end 63 which end is secured to, or formed integrally with, a control spindle 65. The valve cylinder bore 57 is provided with an enlarged portion 57a within which is screw-threaded the valve plug 66. This plug is hollow and'is provided with the shoulders 67 which are arranged to be in abutment with the forward face of the portion 63 which is provided with a neoprene seat, of the valve body 61 when the latter is in the forward position. At the forward end of plug 66, there is a boring 68 which is a slidable lit around the control spindle 65 so that the latter is free to slide therein. A number of radial borings 69 establish communications between the atmosphere and the interior :boring 70 of the valve plug 66. The rear of the valve body 61 is provided with a spring seat 71 and the compression spring 72 is compressed between the shoulder 73 and the shoulder 74 at the rear of the valve bore 57.

As will be seen most clearly from FIGURE 4, the valve body `61 is provided with the annular groove 75 which is arranged so that when the portion 63 of the valve body rests against the shoulders 67 of the valve plug 66, the groove 75 will register with the gas inlet port 58a, a number of radial borings 76 providing cornmunication between the base of the groove 75 and the hollow passage interior `62 of the valve body 61 Further it will be observed that there are a number of radial borings 77 near the front end of the valve body 61, establishing communication from the interior 62 thereof, to the annular space 78 between the walls of the enlarged portion 57a of the cylinder or bore 57,'and the exterior surface of the valve lbody 61.

It will be observed that, upon movement of the Avalve body 61 to the rear, communications is cut off between the gas supply and the gas cylinder 39 by reason of the groove 75 becoming out of register with the gas inlet port 58a, At the same time, however, communication is established between the gas cylinder 39 and the atmosphere through the passages 49 and 5t), the interior 62 of the valve body 61, the radial borings 77, the space 78, around the portion 63 and the hollow interior boring 7G of the valve plug `66 and radial borings 69 in the head thereof.

Secured to the rear of the base plate are the handlebars 80 and 81 which terminate in the handv gr-ips 82 and 83 respectively. Mounted in a suitable boring passing through the ibase plate 51 and the control block 48 is the trigger rod S4 in suitable position so that the bentover end S5 thereof is in proximity to the hand grip 83, in appropriate position to be grasped by an operator. On the front end of the trigger rod 84 there is secured the arm 85 by means of the nut 86.

As can best be observed in FIGURE 3, the arm 85 has a screw-threaded boring at its free end into which is threaded the adjustable screw 87 which carries the lock nut 88. The end 89 of the adjustable screw is arranged to be in axial alignment with the end of the control spindle 65 so that axial movement of the trigger rod 84 will cause the end 89 of the screw 87 to push the control spindle 65 to the rear, cutting olf communication between the gas supply and the gas cylinder 39, and opening communication between the gas cylinder 39 and the atmosphere. Also secured to the trigger rod 84, for movement therewith is the connector piece 90 which is bored to provide a sliding fit around the micro-switch actuating spindle 91 which ts slidably within the boring 92 in the `base plate 51. `The micro-switch actuating Yignition control spindle 91 is bored centrally to receive the petrol valve stem 93 and is further provided with the bevelled shoulder 94 which actuates the micro switch 95 upon movement to the rear thereof, to operate the electrical ignition. Mounted in tapped boring 97 a depending portion 96 of the control block 4S is the petrol control valve body 98 provided with the rearwardly facing valve seat 99. This valve seat is formed from synthetic rubber or neoprene and is `adapted to cooperate with the petrol valve head 100 which is secured to the end of the petrol valve stem 93. The tapping 101 and petrol port 162 provide means ffor connecting the boring 97 toa supply of petrol under pressure (not shown). The boring 97 is formed withV a shoulder against which is seated the sealing assembly 103 which is formed from a synthetic rubber sealer 104 and the t-Wo discs 105 and 106. The disk 105 is provided with a rearwardly facing annular rib 107 which aids the sealing action of the assembly to prevent escape of petrol to the rear. The sealing assembly 103 is held securely in position by means of the hollow plug 108 which is screw-threaded into the rearwardly tapped portion 109 of the boring 97. The plug 108 has an axial boring 110 which is a slidable t around the petrol valve stem 93, and mounted on the valve stern and slidable with respect thereto inside the hollowed-out portion 111 of the plug 108, is the spring retaining washer 112. Surrounding the petrol valve stem 93 within the holloWed-out space 111 is the compression spring 113 having its forward face against the washer 112 and its rearward face against the shoulder 114 at the rear end of the hollowed-out space portion 111.

The rear end of the ignition control spindle is bored out as at 115 and the valve stem 93 extends centrally through said boring to extend beyond the rearmost face 116 of the micro-switch actuating control spindle 91, and is screw threaded at its extremity to provide for the mounting of the adjustment nuts 117 and 118. Mounted upon the rearward end of the petrol valve stem 9'3 is the compression spring 119 which is compressed between the nut 118 and the shoulder 120 in the bottom of the boring 115. The compression spring 119 is considerably weaker than the compression spring 113 and accordingly it will be observed that, as the micro-switch actuating ignition control spindle 91 is moved to the rear, it will merely compress the spring 119 until the face 116 contacts the nut 118 at which point the valve stem 93- will be drawn to the rear to unseat the valve head 160 from the valve seat 99. It will 'be observed, however, that the amount of movement of the ignition control spindle 91 which will take place before the valve stern 93 Will be moved lto open the petrol valve can be adjusted by adjust- ,ing the position of the nut 118 and its associated lock nut 117. In this manner the timing of the actuation of the micro switch 95 and the opening of the vpetrol valve may be correlated so that a spark is produced in the ignition device immediately before petrol commences to issue :forth therefrom.

The forward end of the petrol control Valve body is provided with screw threads 120 for connection of the petrol conduit 121. Similarly the micro switch 95 connectselectrically a suitable transformer which connects tothe forwardly extending high tension cables 122.

Mounted underneath the barrel at the front thereof, `as illustrated in FIGURES l and 2, is the ignition assembly 123, details whereof are best illustrated in FIGURES 5., 6, 7 and 8.

- The ignition; assembly 123 comprises the ignition'block 4124 which is bored to lit around the forward end of the barrel and besecured in position thereon in the manner illustrated in 1 FIGURE 1. The ignition block 124 is bored and tapped on both sides to provide mounting for ,the insulators 1 25 and 126 which are held firmly against 136 is outwardlythreadedto receive the cap piece 138 -which holds infposition thegnozzlejgpiece139, of which thev main nozzle 135 fo11ns .a.part.Y yAsMw-illkbe seen most clearly from FIGURE-6,the nozzle piece 139 consists of thel disk-shapedI portion-140 which l is j heldrlin position between the cap piece 138an`d lthe nozzlehe'a'd l136 which .electrodes-.133 ,and B4-extend from the insulators 125 f and126 throughwhich they pass, to connect to the high .tension cables 122 and arebent around toterminate in positions on opposite. sidesV adjacent to the main petrol Vnozzle 135- which extendsfforwardly and upwardly from `the petrol nozzle head-i136whichis silver soldered into 'the forward end ofthe ;boring :137;which is centrally located 'betweenthe borings1129 Aand'llhtl.` The nozzle head 6 contains two small borings 141 and 142 which form the auxiliary petrol nozzles.

The main ignition nozzle extends Vcentrally from the disk-shaped portion and is substantially tubular in shape, but the flow channel therein forms a right angle near the base thereof as at 143, and in its mounted position the entrance 144 to the rear of the main ignition nozzle 135 faces upwardly. The rear of the boring 137 is tapped to receive the petrol pressure valve 145 which is provided with a screw threaded rearwardly facing extension 146 for connection to the coupling 147 at the front end of the petrol conduit 121. The petrol pressure valve 145 is bored centrally and the interior thereof is provided with the forwardly facing shoulder 148 against which the spring driven valve plunger 149 is urged by the compression spring 150. The valve plunger 149 is provided with the synthetic rubber seat 151 in its rearward end, to effect a proper seal with shoulder 148, and is formed with a plurality of longitudinally flattened faces 151 to provide flow channels for petrol past the valve plunger 149 when the'same has been unseated from the shoulder 148.

The boring 137, internally threaded to receive parts 145 and 153 is provided with the rearwardly facing shoulder 154, providing a seating for the forward end of the compression spring 150. Four angularly disposed borings 155 substantially at right angles to each other are provided in the front of the part 153, for flow of petrol therethrough, when the pressure valve is open, so that a sudden rush of petrol through them will be atomized initially to provide a readily igniteable mixture issuing from the auxiliary nozzles 141 and 142 for ignition by the spark as described below.

The ignition device operates as follows:

When petrol under pressure is applied to the petrol conduit 121 the seat 151 is forced away from the shoulder 148 and petrol flows through the channels 152, through the centre of the petrol pressure valve145, through the angularlydisposed borings 155, and into the boring 137. The pressure of the petrol is relatively great and it moves through the borings 155 and forms an atomized mixture as it proceeds forward towards the nozzle with considerable speed, its momentum carrying two tine sprays of atomized petrol through the auxiliary nozzles 141 and 142 before the petrol has been able to enter the entrance 144 to the main nozzle 135, flow. around the elbow 143, and reach the end of the main nozzle 135. The exceed- `ingly ne spray issued from the auxiliary nozzles 141 'the time petrol. issues from themain igniter nozzle 135,

there is 'a hot flame available to ignite itso that it proceeds forward asa burning rod of petrol which is appropriately positioned to' ignitey the main rod of thickened flame fuel which, by that time, will ybe issuing from the nozzle at vthe forward end of the barrel 10. This ignition flame is continuous as long as the trigger is pressed.

The supply of electrical energy'neces'sary to provide spark to ignite the petrol, the supply of petrol, the supply of gas .and the supply of flame fuel are all accomplished, in connection with the ame throwerl of the present invention, in well known and conventional manner so that it is not believed necessary to describe the particular means of supply herein, suitable apparatus being illustrated in the aforementioned Canadian Army Training Manual.,r

The completely assembled ame thrower operates as follows: v Y l fWhen the operator pulls the trigger rod 84 to the rear,

by pulling on the arm 85,'three actions take place in timed sequence. V v Y (l) Ony moving to the rear, the trigger rod 84 carries with it the micro-switch actuating spindle 91 which moves tension current through the high tension cables 122, up to the electrodes 133 and 134. The circuit grounds itself on the main petrol nozzle 135, creating a continual electrical spark.

(2) The nut 118 and the lock nut 117 are so adjusted on the petrol valve stem 93 that, immediately upon actuation of the micro switch 9S and establishing of the electrical spark, the face 116 contacts the front of the nut 118, moving the petrol valve stem 93 to the rear and opening the petrol valve by moving the valve head 100 otf the seat 99. As previously explained, the petrol issues in very ne jets from the two auxiliary nozzles 141 and 142, and is ignited by the spark, and the ignited spray then ignites the stream of petrol which, by that time, is issuing from the main nozzle 135, producing a continuous ignition flame.

(3) The adjustable screw 87 is so adjusted that, irnmedately upon the creation of the ignition flame, the end 39 thereof contacts the control spindle 65, pushing the valve body 61 to the rear, shutting off supply of gas pressure to the gas cylinder 39, and opening communication between the gas cylinder 39 and the atmosphere.

This reduces the pressure against the head 36 of the pintle piston 3S, and as this pressure drops, the pressure of the liame fuel within the barrel 10 of the gun, pressing on the front face of the pintle piston 35, moves the whole pintle to the rear, unseating the conical portion 31 at the front of the pintle, from the valve seat 13 of the conical nozzle component 12, and allowing the fuel to be ejected as a rod, through the nozzle tip 14. The fuel passes through the ignition flame and is ignited by it.

When the trigger rod is released by the operator, the compression springs 72 and 113 re-assert themselves, returning the trigger rod 34 to its normal position of rest, ready for another shot. In doing this the sequence of events is as follows:

The Valve body 61 reseats itself, cutting off communication between the gas cylinder 39 and the atmosphere, and establishing communication with the exible hose gas line 60, lling the gas cylinder 39 with gas under pressure, which moves the pintle 29 forward to seat the portion 31 thereof, against the valve seat portion 13 of the conical nozzle component 12, shutting E the stream of flame fuel. In moving forward, the petrol valve stem 93 seats the valve head 100 on the valve seat 99 to shut oif the petrol, and at the same time the micro-switch actuating ignition control spindle 91, in moving forward, operates the micro switch to cut off the electrical current. On closing of the petrol valve 99, the petrol pressure valve 150 moves against the shoulders 148, preventing escape of the petrol within the conduit 121, so that petrol does not escape and drip from the nozzles between shots.

From the foregoing it will be seen that the action of the gun according to the invention is exceedingly simple and rapid, permitting shots to be tired in extremely rapid succession.

Normally speaking, the working pressure employed will be approximately 280 pounds per square inch, but higher or lower working pressures may be used with good results.

What I claim as my invention is:

1. In a amethrower of the type wherein a rod of ame fuel is projectable from a nozzle at the front of a barrel to which flame fuel is supplied under pressure and wherein the projection of said rod of flame fuel is controlled by a pintle having a conical tip situated within the barrel and arranged for movement into and out of seating engagement with a conical seat in said nozzle, said flame thrower comprising electrically ignited petrol ignition means for igniting said rod of flame fuel and control means for actuating said pintle and said ignition means in timed sequence, in combination; a unitary pintle comprising; a forward portion having a conical tip thereon adapted for cooperation with the conical seat in the nozzle, and having mounted thereon a plurality of uniformly spaced apart radial vanes arranged to bear against the inner wall of the barrel to keep said pintle axial aligned therewith; a rearward portion in axial alignment with said forward portion and united therewith, said rearward portion being more slender than said forward portion and projecting rearwardly of said barrel; and a pintle piston, having a head and a body portion, the latter portion being larger in diameter than said rearward portion of said pintle and being secured to the end of said rearward portion; a generally elbow-shaped gun body having a passage therethrough for supply of flame fuel to said barrel and formed with a rearwardly extending portion having a boring extending therethrough in axial alignment with said gun barrel and of a diameter adapted to provide a freely sliding t with the body portion of said pintle piston; a cylinder block having a gas cylinder formed therein and secured to said rearwardly extending portion of said gun body with said gas cylinder in axial alignment with the boring therein, said gas cylinder being of suitable diameter to provide a sliding t around the head of said pintle piston; and means, including a `gas port formed in said cylinder block for supplying Igas under pressure to said gas cylinder rearwardly of the head of said pintle piston and exhausting gas under pressure therefrom; the length of said pintle piston being such that when the conical tip of the forward portion of the pintle is seated in said conical seat, the head of said pintle piston is in the forward end of said gas cylinder.

2. The combination defined in claim l including a recess in said boring to accommodate an oil sealing ring, and an oil sealing ring seated therein which wipes the surface of the body portion of the pintle piston to seal the flame fuel in the barrel against escape to the rear.

3. The combination defined in claim 2 including a gas sealing washer on the head of the pintle piston adapted to prevent passage of gas between the surface of the gas cylinder and the pintle piston head, and vent means at the front end of the gas cylinder communicating the interior thereof to the atmosphere.

4. The combination defined in claim 1, including at least one recoil washer within the rearward end of the gas cylinder.

5. The combination defined in claim 1 in which said means for supplying gas under pressure to said gas cylinder rearwardly of the head of said pintle piston and exhausting gas under pressure therefrom comprises; a control block secured to a side of said cylinder block, said control block having a boring therein extending from the forward end thereof part way through said control block in a direction generally parallel to the axis of the gas cylinder, said boring having VVan enlargement at the forward end thereof, said control block having a gas port arranged to lie in register with the gas port in said cylinder block leading to the rearward end of said boring and a -gas supply port adapted for connection to a supply of gas under pressure leading into a central portion of Said boring; a valve body having a hollow centre and axially slidable within said boring, said valve body being formed with a disc shaped valve head at the forward end thereof, centrally positioned port means affording communication between the periphery of said valve body and the hollow centre thereof and radial vents aifording communication between the hollow centre of said valve body and the forward end of the annular space formed between the walls of "said enlargement of said boring and the periphery of said valve body; a plug secured in the forward end of said boring, said plug having a central passage therein vented substantially radially to the atmosphere and having an axially disposed bushing of smaller diameter than said central passage at the forward end thereof and being provided at its'rearward end with an annular valve seat for said disc shaped valve head; a valve stem axially slidable in said bushing, united tosaid valve head and extending through said bushing forwardly thereof; spring means urging said valve body forward to Aa position in which said valve head is seated on said annular valve seat, said centrally positioned port means on said valve body being so positionedas to register with said gas supply port when said valve head is so seated; and means for displacing said valve stem to the rear against the pressure of said spring means simultaneously to cut olf said -gas supply port and unseat said valve head from said annular valve `seat to establish communication between the hollow centre of said valve body and the atmosphere.

6. The combination defined in claim in which said control block includes a second boring passing completely therethrough from front to rear and said means for displacing said valve stem to the rear comprises a trigger rod slidable within said second boring, an arm secured to the front end of said trigger rod, and a contact member mounted on the end of said arm and in axial alignment with said valve stem and arranged on withdrawal of said trigger rod to the rear to contact said valve stern and carry it to the rear.

7. The combination defined in claim 6 in which said 1o micro-switch as said spindle is moved rearwardly may be adjusted; and spring means urging said Valve stem forwardly with respect to said spindle.

10. The combination defined in claim 9 in which said control block includes a depending portion and said petrol valve is positioned therein.

barrel to which flame fuel is supplied under pressure and wherein the projection of said rod of flame fuel is controlled by a pintle having a conical tip situated within the barrel and arranged for movement into and out of seating engagement with a conical seat in said nozzle, said llame thrower comprising electrically ignited petrol Vigtrigger rod is coupled to actuating means for the ignition Y means.

8. The combination defined in claim 7 including a longitudinally slidable spindle mounted parallel to said trigger rod; means connecting said spindle to said trigger rod whereby said trigger rod and said spindley may be moved rearwardly as a unit; a micro-switch electrically connected in a high tension circuit forming a part of said electrically actuated petrol ignition means and mounted in operative association with said spindle, said spindle having means arranged to engage an actuating member of said micro-switch upon movement of said spindle to the rear.

9. The combination defined in claim 8 in which said spindle has a longitudinal boring, and said combination further comprises a petrol valve for controlling supply of petrol to said ignition means mounted in alignment with said spindle forwardly thereof in a fixed part of said amethrower, said petrol valve comprising a petrol inlet port and a petrol outlet port, said outlet port leading forwardly of said petrol valve and comprising a rearwardly facing annular valve seat; a valve head arranged for cooperation with said valve seat; a valve stem united to said valve head and passing through said boring in said spindle to project to the rear thereof; means carried by the rearwardly projecting end of said valve stem for contacting the end of the spindle whereby the valve stem and valve head will be carried rearwardly with said spindle; said means on the end of said valve stem being axially spaced apart from the end of said spindle, and being axially adjustable whereby the time of opening of said petrol valve relative to the time of actuation of said nition means for igniting said rod of flame fuel and control `means for actuating said pintle and said ignition means in timed sequence, in combination; ignition means comprising a body portion secured beneath thebarrel of the amethrower at the forward end thereof, said body portion having a boring formed therein substantially parallel to said barrel; means for supplying petrol under pressure to the rear end of said boring; secured within said boring a plug formed with a plurality of outwardly directed atomizer passages therethrough; jet means secured in the forward end of said boring, said jet means comprising a centrally located forwardly directed main jet nozzle consisting essentially of a tube extending forwardly of said body portion and having a flow channel ypassing up the centre thereof and havinga radially'disposed inlet port opening into the interior of said boring; and said jet means having two secondary jet passages of very small diameter disposed parallel to said main jet nozzle in proximity thereto; electrical ignition means including two electrodes disposed to provide a spark gap on either side of vsaid. main jet nozzle intermediate the ends thereof; and means for supplying high tension electricity to said electrical ignition means.

V12. The combination defined in claim 11 including a pressure valve mounted in said boring rearwardly of said plug, said pressure valve being arranged to allow passage of petrol to `said jet means only when the pressure thereof exceeds a predetermined value.

References Cited inthe file of this patent UNITED STATES PATENTS 1,304,710 Seidler May 27, 1919 j 1,340,012 Cave May 11, 1920 1,851,263 Roach Mar. 29, 1932 2,331,388 Graham Oct. 12,1943Y Y 2,417,981 Graham Mar. 25, 1947 2,569,887 Goddard Oct. 2, 1951

Images