US2338440A - Fire-extinguishing and preventing system for motor vehicles - Google Patents

Description

Jan. 4, 1944. w KQCHMANN 2,338,440

FIRE EXTINGUISHING AND PREVENTING SYSTEM FOR MOTOR VEHICLES Filed June 15, 1958 53- z maxi/1111x111 gill/143 /A V 47 H gK I lnvenzor: an??? Y 4 4; [2. MMZ

Patented Jan. 4, 1944 nane FIRE-EXTINGUISHING AND PREVENTING SYSTEM FOR MOTOR VEHICLES Wilhelm Kochmann, Berlin, Germany; vested in the Alien Property Custodian Application June 15, 1938, Serial No. 213,902

1 Claim.

motor vehicle and act reliably in all circum-,

stances which might possibly arise in connection with such vehicle are not regarded in practice to constitute a safety means at all against fire, and consequently are not employed. Since now the causes of a fire and the circumstances in which the same may arise are extremely numerous and complicated in vehicles of different types, a protection against fire is not obtainable by single means, but only by a combination of different means and their adaptation to one another and to different extents of danger to form a complete fire-preventing system. To facilitate the description, but without in any way limiting the invention thereby, reference Will be made in the following to the safeguarding of aircraft, in which the possibilities of a fire occurring are the most numerous, so that in other vehicles certain simplifications may be possible, particularly as regards the means for causing the system to take effect.

A fire-preventing system according to the invention comprises one or more automatic and arbitrarily acting actuating means which, when fire is liable to occur, set the sprinkler system into operation and extinguish the fire before it has time to obtain a hold or, by the cooling of hot parts of the vehicle and/or enveloping the same in fire-preventing vapors or the like, prevents the ignition of fuel, oil or other inflammable substances. Automatic actuating means of this nature consist of devices which respond to the heat of a fire or parts which have become heated, to the light of a fire or to the jolts or the concussion produced when the vehicle strikes an obstacle. Photo-electric light responsive connections or also thermal connection systems making use, for example, of resilient switches having readily fusible portions or designed on the lines of bimetallic switches are known per se. Actuating means which respond to jolts or impact require in the case of a fire-preventing system designed to act in all possible circumstances cer tain characteristics. They must respond to jolts which may occur in any direction in any par ticular type of vehicle. At the same time,-however, they must be so adapted that they will not respond to sudden variations in position' or to sudden but harmless variations in speed, but only to jolts which are so powerful that they attain or exceed the maximum load capable of being applied to parts of the vehicle or its contents, damage to which might be liable to result in fire, so that there will be no unnecessary or possibly even dangerous actuation of the sprinkler system. Since the powers of resistance of the said parts vary in the case of jolts proceeding in different directions, so that for example the wingsof an aircraft present different resistances to impact occurring from below or from the front, these T shock-actuated means should preferably be so adjusted that they respond differently to jolts or impact occurring in different directions. It is ated devices each adapted to act in one or in two directions only that they supplement each other to form an actuating device responding universally to jolts occurring in all possible directions. In this case it is a particularly simple matter to furnish the separate shock-actuated devices with different degrees of sensitivity, for example by providing the inertia elements causing the actuation with different weights or by imparting different strengths to the springs or other retention means for these elements in respect of the different directions concerned. In certain cases, particularly in the case of aircraft of large size, it may be important to provide not only a central shock-actuated actuating means readily accessible to the pilot or the passengers, but also a plurality of independently acting shock-actuated devices at different points which are particularly endangered in the event of impact, so that these are struck with a force equal to that acting on the initially endangered parts, and are not merely acted upon, as in the case of the central device, by an impact which has already been attenuated by the deformation of certain external parts of the aircraft.

As additional means for causing reliable operation of the fire-preventing system in all circumstances arising the invention does not makeuse of a stored gas pressure for conducting the extinguishing agent to the endangered parts of the aircraft, but makes provision for generation of the gas pressure at the moment of requirement from a chemical pressure-generating reaction,

preferably by the combustion of non-explosive Chemical reactions of this nature, which are initiated for example by means of an substances.

ignition device, have the advantage that they can be initiated by very small forces, which are always present even in the case of very small mass of the inertia Weights in the shock-actuated means and in the case of unfavorable direction of the jolt or impact, and then supply independently of the force of the impact the gas pressure necessary for the propulsion of the extinguishing agent. Additional advantages consist in the fact that the chemicals producing the gas pressure at the time of requirement are durable, cannot escape or dissipate by reason of leakage and moreover, particularly when using substances producing the gas pressure by non-explosive combustion, are capable of being employed in solid and compact form. In addition, these substances react independently of the chemical nature of the extinguishing agent or of the outer temperature which, in the case of certain vehicles, is subject to considerable fluctuation. Further, the ignition of these substances is possible by means of cheap and simple electric ignition devices without mechanically moved initiating means.

In order that a fire-preventing system of the character described will operate reliably in all circumstances concerned in respect of a given type of vehicle the part of the system generating the gas pressure must be placed in communication with a container for the fire-extinguishing agent which permits of a discharge of the fire-extinguishing agent in all positions of the vehicle. For example, the container for the extinguishing agent, with corresponding connection of the pipes for discharge of the liquid, may be suspended'in universal disposal or, in the manner known per se, furnished with movable internal members which ensure a proper discharge of the liquid, for example with a flexible pipe which is loaded with a weight at its free end, so that the discharge of the liquid always occurs from the lowest point of thecontainer. Since, generally speaking, in the case of vehicles, on account of the necessity of extinguishing burning fuel and oil, aqueous extinguishing agents cannot be employed, and primarily organic substances are used, such as tetrachloride of carbon, trichloride of ethylene and the like, generation of the gas pressure by way of wet reactions must take place separately from the extinguishing agent. Special precautionary measures are then required to be taken to ensure that the gas pressure resulting from the chemical reaction is able to act on the extinguishing agent independently of the position of the vehicle.

Care is also required to be taken that the reaction producing the gas pressure proceeds steadily without disturbance, and that undesirable byproducts-of the reaction, such as heat, soot, smoke or the like, are unable to exert a detrimental effect. When employing the substances which produce the gas pressure by non-explosive combustion and are particularly suitable for protecting vehicles against fire it is desirable to provide the cartridge or container in which the substances are stored, consigned and also burnt in the extinguishing liquid itself, so that during the combustion it is surrounded on all sides by a sufficient depth of the extinguishing liquid despite the decrease in the volume of the latter owing to its discharge. It is, therefore, not desirable to provide the reaction container or the cartridge for these combustible substances in .a secondary container which is accommodated in the extinguishing agent and the wall of which is only a relatively slight distance away from that of the l 5*; vehicle.

reaction container, as in this case the space between the two containers acts in insulating fashion and impairs the assimilation of the heat of reaction by the extinguishing liquid. If on the other hand the extinguishing liquid surrounds the cartridge to a sufficient depth and the gases are compelled to pass through the same, the gases are also cooled, and the soot and smoke components or other residual products of combustion contained therein are washed out. They then remain distributed in extremely fine suspension in the extinguishing liquid and do not contaminate the same.

Additional details of construction of the new fire-extinguishing and preventing system which appreciably assist to render the system perfectly reliable under all conceivable conditions and to simplify to the utmost its arrangement and operation will be described in conjunction with the different embodiments shown in the drawing. In the latter Fig. 1 indicates diagrammatically the outlay of a fire-preventing system for a large vehicle having numerous actuating devices.

Fig. 2 is a section taken through a cartridge containing a combustible substance for supplying gas pressure, the said cartridge being mounted in a container for the extinguishing agent.

Fig. 3 is a section through a heat-consuming reaction container.

Fig. 4 is a perspective view of a shock-actuated actuating device having different degrees of sensitivity in difierent directions.

Figs. 5 and 6 illustrate possible embodiments oi the manner in which the sensitivity of the actuating device can be readily varied during the movement of the vehicle.

In Fig. l, l is the container for the extinguishing agent having inserted therein the cartridge 2 containing the substance which generates the gas pressure by combustion. 3 is the conventional internal arrangement by means of which the extinguishing agent is discharged from the container independently of the position of the 4 is the pipe which conducts the extinguishing agent to the single points of dis charge 5 situated in the vicinity of the endangered parts. 5 is a current source provided on the vehicle, and l is a central shock-actuated actuating device (for example as illustrated in Figs. 4 to 6), which is effective in all possible directions and the sensitivity of which can readily be varied by the occupants of the vehicle when the latter is in motion. Shock-actuated actuating 3 devices 8 are provided at particularly endangered points of the vehicle, so that in the case of collision with any obstacle they receive practically the same impact as the said parts, and not merely an attenuated impact such as that imparted to the central device I. There are provided two thermal contacts t of the conventional kind, whilst H3 is a photo-electric switch of the kind known per se which responds to the light of a fire. H is an arbitrary actuating device for the whole system. The leads 12 are in part common to all of the actuating devices and acted upon by suitable means, such as an electrical ignition device, for the purpose of initiating the reaction generating the gas pressure. i3 is a switch fitted in the pipe 4, for example a small cylinder having a piston and a spring, which is moved by the extinguishing agent under pressure .and exerts an auxiliary efiect, for example closes the fuel pipe or disconnects the current in the vehicle.

If one of the devices 1 to H closes the circuit of the current source 6, the ignition device of the cartridge 2 is set into operation and in turn ignites the combustible substance in the cartridge. The gas pressure thus generated forces the extinguishing liquid from the container l through the pipe 6 to the endangered points.

Fig. 2 shows on larger scale the cartridge 2, which projects into the extinguishing agent and is thus cooled.

I4 is a socket adapted to receive the cartridge 2, which contains the substance 16 compressed into compact form and generating the gas pressure by non-explosive combustion. This substance is acted upon by the two independent electrical ignition devices Ho and I'll) which, proceeding from the rear end of the cartridge, terminate in the insulated contacts l8a and I82). I9 is the screw-on cover, which is adapted to be applied in gas tight fashion, for example by means of the packing 29, and in which the contacts Zia and 2H1 are so mounted in insulated fashion that by the application of the cover the ignition device is connected up with the circuit. I is a small air pocket in the cartridge 2 formed by the distance piece 22, whilst 23 is a moistureproof cover having the gas outlet aperture 25, which is closed, for example, by a destructible foil 24 soldered thereto. This outlet aperture may also be provided in the form of a plurality of smaller apertures. The strength of the seal is preferably such that it does not open until the pressure in the reaction chamber has reached such a degree that it is capable of overcoming not only the hydrostatic pressure but also the pressure of the mass arising from any movement of the system (pressing pressure from acceleration or retardation). 26 is a screen through which the gas is compelled to pass for the purpose of better distribution in the liquid. 21 is a plug which is composed of clay or the like and is furnished with a passage and which ensures that the part of the cartridge in which the combustion takes place extends to a sufiicient degree into the extinguishing liquid, e. g., near its center, independently of the position of the vehicle and the progressive discharge.

28 (Fig. 1) is the usual air pocket in the container l. 29 is the filling device for the extinguishing agent, which device is so arranged that when pouring in the extinguishing agent the air pocket is maintained automatically.

In Fig. 3 there is shown another embodiment of the cartridge in which the combustion reaction producing the gas pressure does not take place within the extinguishing liquid. Other means are accordingly employed for making the heat of the combustion gases and the radiation of the hot cartridge harmless. 30 is the pressure-resisting wall of the reaction container, in which the cartridge 2 with the electrical ignition means Ila and 11b and the cover i9 is mounted in a manner similar to the embodiment in Fig. 2. In the cartridge the substance I5 producing the gas pressure upon combustion is surrounded by a jacket composed of heat-oonsuming material, for example by a pressed hollow cylinder 3| consisting of sodium bicarbonate with or without the addition of a catalyst, which is decomposed by the heat of the reaction, thereby producing additional carbonic acid with the consumption of heat. About the container 38 there is disposed a second wall 32 consisting, for example, of thin sheet metal. The intermediate space between the two walls, whilst leaving room for expansion,

is filled out with a heat-consuming, for example fusible substance, such as wax, fusible salts or the like. 33 is the pipe for conducting the generated pressure gas to the container for the extinguishing agent. The outlet aperture is closed by a movable filter device, which consists, for example, of the fixed screen plates 34a and 3412, a loosely disposed intermediate layer of asbestos 34c, and a ring 34d. After removal of the cover the two screen plates and the intermediate layer can be readily withdrawn by the ring with the aid of a hook for cleaning purposes. At the same time they scrape from the walls of the container 39 any traces of soot, smoke or ash or any other undesirable components.

Fig. 4 shows a possible embodiment of a shockactuated actuating device, which comprises a plurality of small and simple single actuating devices supplementing one another to form a shockactuated means which is effective in all directions. Owing to its cheapness, simplicity and ready adjustability an embodiment of the nature is to be preferred to a shock-actuated device in which an inertia element is shiftable in all directions. Six tubes 39 composed of insulating material are preferably united to form a block or common container. In each of these there is located, in accordance with, Fig. 5 or 6, a spring at and an outwardly shiftable inertia weight 42 composed of metal, in which connection the sensitivity of actuation may be made to vary in different direction by making the springs of different strength or the inertia weights of diiTerent size. In the path of the resiliently held inertia members, as shown in Fig. 5, there are provided in difierent spacial disposal two pairs of contacts so, ll. The pair of contacts 40 situated nearer to the weight 42 are normally not connected up with the circuit. If an impact is so powerful that the inertia weight reaches the outer pair of contacts 4!, the circuit is completed and the chemical reaction caused to be initiated. If for certain reasons, for example in the event of a forced landing, it is desired to make the shockactuated device more readily responsive, the circuit is switched over to the inner pair of contacts M. A slight movement of the inertia weight is then sufiicient to complete the circuit and cause the system to take effect.

In the embodiment of the actuating device according to Fig. 6 the inertia weight 42 possesses a boring 43 extending through the casing or an outwardly projecting eye. Through the boring or eye and the casing there is passed in splintlike fashion a wire or needle 44 consisting of brittle steel, which holds the weight in position. In the event of a sufiiciently powerful jolt or impact the needle is broken, and the weight moves in opposition to the weak spring 45 against the contacts ii. If the wire is out or the splint-like needle M withdrawn When the vehicle i in mo tion, the inertia weights are merely held by the weak springs t5, and a comparatively slight jolt or shock is sufficient to cause the actuation. It is also possible to secure to the one end of the Weights wires in loop-like form having a specific breaking strength, and to pass a splint-like pin through all loops, so that the weights are all readily operable when the pin is withdrawn and it is no longer necessary for the wires first to break for the purpose of the actuation.

What I claim as new and desire to secure by Letters Patent is:

In a fire-extinguishing and preventing system for motor vehicles, a container having an extinguishing agent therein, a reaction container having a substance therein adapted to produce pressure gas by chemical reaction, means for initiating the said reaction, means for actuating the said initiating means, said reaction container being provided with an outlet for conducting the said pressure gas to the said extinguishing agent for discharging the said extinguishing agent from the said first container, and a seal in the said outlet which is only opened when the pressure in the said reaction container exceeds both the hydrostatic pressure as well as the pressing pressure of the said extinguishing agent caused by acceleration o1 retardation of the vehicle on which the system is mounted.

VVILHELM KOCHMANN.

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