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Publication numberUS3872769 A
Publication typeGrant
Publication dateMar 25, 1975
Filing dateJul 23, 1973
Priority dateJul 23, 1973
Publication numberUS 3872769 A, US 3872769A, US-A-3872769, US3872769 A, US3872769A
InventorsRosling Thomas H
Original AssigneeUs Navy
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Cartridge actuated flame system
US 3872769 A
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Description  (OCR text may contain errors)

1 1 Mar. 25, 1975 1 1 CARTRIDGE ACTUATED FLAME SYSTEM Thomas H. Rosling, Falls Church, Va.

{73} Assignee: The United States of America as represented by the Secretary of the Navy, Washington, D.C.

221 Filed: July 23,1973

211 Appl. No.: 381,829

[75] Inventor:

UNITED STATES PATENTS 1.304.710 5/1919 Seidler 431/91 2.943.673 7/1960 Hickman... 89/1 A X 2.952.309 9/1960 89/1 A X 3,711,223 1/1973 Schaible et a1. 417/342 X 3,718.409 2/1973 Brandenberg et al. 417/342 Primary Examiner-Benjamin A. Borchelt Assistant Examiner-C. T. Jordan Attorney, Agent, or Firm-R. S. Sciascia; P. Schneider s7 ABSTRACT A flame thrower utilizes a solid propellant grain to provide gases which force a slug of flammable fluid out a gun barrel. Two working cylinders are connected to flammable-fluid, supply tank. Working pistons, 180 out of phase, pump the fluid to a gun which ignites and directs the fluid stream. The gun is connected to a control system which actuates gas generators that supply gas to driving chambers. The driving chambers contain two driving pistons connected to the working pistons. The driving pistons are 180 out of phase, and the driving chambers are connected by an hydraulic line whereby movement of one driving piston in one direction forces the other driving piston in the reverse direction to reset and reload the mechamsm.

8 Claims, 2 Drawing Figures I 1. L i CK 1 fig 1 s2 s2 PATENTEDHARZSIQYS SHEET 2 0f 2 N QFK CARTRIDGE ACTUATED FLAME SYSTEM BACKGROUND OF THE INVENTION The present invention relates generally to flame throwers and more specifically to a flame thrower which uses an unpressurized supply of flammable fluid and provides continuous fire capability.

Existing flame throwers use compressed air to force flammable fluid from heavy-walled containers thru a gun and or nozzle. In the gun the fluid is ignited and projected thru the air to the impact zone. Support for this type of system requires a 3,000 psi air compressor, regulators for reduction to 325 psi, high-pressure air tanks, and low-pressure fuel tanks. Heavy-walled pipes with large, expensive valves connect the pressurized fuel tanks to each other and the gun. Such systems are quite heavy, since the high pressure air must be contained in strong tanks. In addition, the nearness of the flammable fluid and high pressure air present a great hazard should the system be hit with a projectile. Because of their complexity, these prior systems were difflcult to maintain, particularly the 3,000 psi compressor which is quite costly. Because of weight and size limitations. such flame throwers cannot be employed on small craft or vehicles, and their complex operation often leads to poor reliability.

SUMMARY OF THE INVENTION The present invention employs a gas generator to power a piston that drives a shaft of flammable fluid out of the barrel of a gun in a squirt gun type of action. Dual working cylinders provide a continuous fire capability. and the use of a gas generator eliminates the need for a high pressure source and its concomitant set of pressure control devices. Flammable fluid is stored in an unpressurized container and withdrawn from the container in a pumping-type action just prior to projection thru the gun barrel.

An object of the present invention is to use an unpressurized flammable-fluid supply in a flame-thrower system.

Another object is to reduce the weight of a flamethrower system and increase its reliability.

A further object is to eliminate the hazard of a highpressure. air source in a flame-thrower system.

Other objects, advantages, and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawmgs.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a schematic diagram of the flame-thrower system of the present invention; and

FIG. 2 is a schematic diagram of one possible control system.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1, which illustrates a preferred embodiment of the flame-thrower system, shows a gun 10, or fluid release-and-aiming means, connected by a flexible line 12 to a manifold 14. Manifold lines 16 and 18 connect the gun to working cylinders 20 and 22. Within the working cylinders are working pistons 24 and 26 which are 180 out of phase. Flammable-fluid, supply tank 28 contains an unpressurized flammable fluid, Napalm for example. Supply lines 30 and 31 connect the unpressurized supply tank 28 to the working cylinders 20 and 22. Shafts 32 and 34 connect the working pistons 24 and 26 to the driving pistons 38 and 36. The driving pistons 36 and 38, like the working pistons, 'are 180 out of phase in the driving piston chambers 40 and 42. An hydraulic line 44 connects the driving piston chambers 40 and 42. Gas generators 46 and 48 are mounted on the rear of the driving piston chambers 40 and 42. The gas generators may be a cluster of individual solid propellant grains. The grains may be activated individually to produce gas and drive the pistons 36 and 38. Electrical lines 50 and 52 connect the gas generators to a control box and power supply 58. The control box 58 also controls opening and closing of the solenoid valves 54 and 56. The control box 58 is activated by the gun 10 thru electrical lines 60 and 62. I

As shown, working cylinder 22 would be filled with a flammable fluid that had been withdrawn from tank 28 when piston 26 was moved rewardly in the working cylinder 22. Driving cylinder 42 would preferably be filled with an hydraulic fluid, although simply allowing air to accumulate in the driving cylinder 42 would also work. Solenoid valves 54 and 56 would be in the open position.

One possible electrical system which could be employed to control the present invention is depicted in FIG. 2. As can be seen, control box and power supply 58 contains a battery 64 or other source of electrical power and two motors 66 and 68. The motors are synchronized and simultaneously rotate armatures 67 and 69. The armatures connect the positive battery terminal to elongated contacts 70 and point contacts 74 to activate the solenoid valves 54 and 56 and gas generators 48 and 46 in their proper sequence upon closing of the switch or trigger 11.

Operation of the invention will now be described. As shown in FIG. 1, working cylinder 22 is filled with flammable fluid and driving cylinder 48 with hydraulic fluid. Both solenoid valves 54 and 56 are closed. Pulling the trigger on the gun l0 closes switch 11 which simultaneously opens solenoid valve 78, starts motors 66 and 68 and connects armatures 67 and 69 to the power supply. Opening valve 78, which is within gun 10, allows communication between line 12 and the gun barrel. As shown in FIG. 2 when armature 67 touches contact 70, solenoid valve 54 opens and vents driving chamber 40. At the same time one of the solid propellant cartridges is activated in gas generator 48. The high pressure gas drives piston 36 and thus piston 26 forward forcing flammable fluid out of the gun barrel. Simultaneously, piston 36 forces hydraulic fluid into cylinder 40, driving piston 38 to the rear. Rearward movement of piston 38 draws working piston 24 back. Rearward movement of piston 24 draws fluid from supply tank 28 into cylinder 20. Keeping the switch or trigger 11 closed causes the motors 66 and 68 to rotate armatures 67 and 69 simultaneously. When the arm atures reach contacts 72 and 76, solenoid valve 54 will close and valve 56 will open venting cylinder 42. At the same time a propellant cartridge 82 in gas generator 46 will be activated and the firing and reloading cycle will be repeated. Continuous fire can thus be achieved.

The cylinders 20 and 22 and the pistons 24 and 26 could be made of plastic to reduce the possibility of sparks. The various lines, such as l2, l4, l6 18, 30 and 31 could be made of a rubber hose material or other suitable flexible material. Rather than a battery for a power supply, the vehicle on which the system is mounted might provide adequate power. Obviously many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

What is claimed is:

l. A fluid-ejecting system comprising:

means for holding a fluid;

first and second cylinders connected to the fluid holding means;

means within said cylinders for withdrawing fluid from the fluid holding means into the first cylinder and simultaneously forcing fluid out of the second cylinder when, and only when, fluid is flowing into the first cylinder; and

ejection means connected to said cylinders and having a barrel member for releasing from the system the fluid being forced out of either of said cylinders and for aiming the released fluid.

2. The system of claim 1 wherein the withdrawing and forcing means comprises:

first and second pistons within said first and second cylinders, 180 out of phase;

means for simultaneously moving said first and second pistons in opposite directions;

first flow line means connected between the fluid holding means and the cylinders; second flow line means connected between the cylinders and the fluid releasing-and-aiming means; and

valve means in the first and second flow line means for only allowing flow from the fluid holding means to the cylinders, and from the cylinders to the fluid releasing-and-aiming means.

3. The system of claim 2 wherein the means for simultaneously moving said first and second pistons comprises:

third and fourth cylinders having forward and rear ends;

gas generating means connected to said third and fourth cylinders for selectively producing gases in said third or fourth cylinder; and

driving means within said third and fourth cylinders responsive to said gases for moving said first and second pistons simultaneously in opposite directions.

4. The system of claim 3 wherein the gas generating means is connected to the rear of said third and fourth cylinders and wherein said driving means comprises:

third and fourth cylinders 180 out of phase and connected to said first and second pistons; and

a transfer line means connected between the front ends of said third and fourth cylinders.

5. The system of claim 4 wherein the fluid releasingand-aiming means comprises a gun having a barrel connected to said second flow line means.

6. The system of claim 5 wherein said gas generating means includes a plurality of gas generators connected to the rear of said third and fourth cylinders and a control means connected between said gun and said gas generators for selectively activating said gas generators.

7. A fluid-ejecting system comprising, in combina' tion:

means for holding a fluid;

first and second working cylinders individually coupled with said fluid-holding means, each cylinder having a piston therein;

third and fourth drive cylinders, each having a piston therein. the pistons of the third and fourth cylin ders and being mechanically connected to drive the pistons of the first and second cylinders. respectively, one of the drive cylinders being filled with fluid;

pipe means for connecting corresponding ends of said drive cylinders so that, when the piston in one cylinder moves forward. it drives the fluid through the pipe means into the other cylinder thereby moving the piston of the latter backward, and vice versa, the movements therefore being conjoint and l out of phase, the coupled pistons in the working cylinders being driven simultaneously to withdraw fluid from the fluid-holding means into each working cylinder when its piston moves backwards and to move fluid out of the cylinder when its piston moves forwards;

gun means, coupled to receive the fluid moved out of each working cylinder, said gun means having a barrel member for releasing said fluid and for aiming said fluid;

means, coupled to said driving cylinders, for moving each driving piston forward individually and alternately; and

triggering means coupled to said moving means for causing said moving means to operate.

8. A system as in claim 7, wherein said triggering means is located on said gun means.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1304710 *Apr 20, 1918May 27, 1919Frederick CAutomatic itbe-thboweb
US2943673 *Mar 27, 1945Jul 5, 1960Hickman Clarence NFlame thrower
US2952309 *Jan 16, 1958Sep 13, 1960Fay Bernard FFlamethrower
US3711223 *Jan 11, 1971Jan 16, 1973Case Co J IHydraulic control system for concrete placer
US3718409 *Oct 9, 1970Feb 27, 1973Aro CorpReciprocating pump control system
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4247281 *Jun 7, 1979Jan 27, 1981Western Helicopter Services, Inc.Slash burning
US4276661 *Jan 30, 1979Jul 7, 1981Baker William HWave-making apparatus
US4276664 *Jan 30, 1979Jul 7, 1981Baker William HApparatus for wave-making
US4527954 *Jan 14, 1983Jul 9, 1985Halliburton CompanyPumping apparatus
US5429494 *Oct 1, 1993Jul 4, 1995Plum Creek Timber Co., L.P.Low pressure transportable igniting device using volatile liquid fuel
US7578451 *Jan 11, 2006Aug 25, 2009Sulzer Metco AgApparatus for thermal spraying
CN102207360BMar 31, 2010Oct 30, 2013深圳华强智能技术有限公司Natural gas flaming device
U.S. Classification89/1.11, 417/342, 431/91
International ClassificationF41H9/00, F41H9/02
Cooperative ClassificationF41H9/02
European ClassificationF41H9/02