US 2306321 A
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Bees 22, 3942 R. N. ROBERTS AERIAL DEVICE FOR FIRE EXTINGUISHING, ETC
Filed NOV. 20, 1939 IN VENTOR.
atente en. 22, ldZ
AER DEVICE FOR FIRE EXTINGUJISG, ETC.
Ronald N. Roberts, Glendale, Calif.
Application November 20, 1939, Serial No. 305,330
(Cl. 244-l36) 6 Claims.
My invention relates to the distribution of granular materials, fluids, objects and the like from the air to the earth or other surfaces below, and applies to a wide variety of useful applications including fire extinguishing, fire prevention, dusting or spraying for pest control, seeding, fertilizing, etc., etc., as well as to any art where a timed or delayed opening parachute is useful.
A particular object of the invention is to provide for accurately timed control whereby a container or the like, dropped from an airplane, or projected by a catapult, or otherwise launched in aerial flight, may be caused to automatically stop or become retarded when at the correct altitude and location to there release its contents in a manner to spread them over a wide area.
In fire fighting, as well as in many other arts, it has become the practice to drop or hurl fragile bombs such as light metal cans or even paper bags and to depend upon their impact with the ground to burst them and distribute the contents. This method ofiers the recognized objection that the materials are distributed too closed to the ground and spreading depends upon prevailing Winds and is decided inefiicient; much material remaining close to the spot of impact.
It is an object of my invention to provide that a bomb or container falling from a given elevation will, upon reaching a predetermined lower elevation act to release its contents in a widely distributed spray. The distance above the ground at which the material is to be released depends upon conditions. Thus in a forest fire in tall timber a fire extinguishing or retarding chemical should be released at a higher elevation than would be the case in a grass fire pr brush fire. to provide that the elevation at which the contents are released shall be under control or predeterminable.
Another object of my invention is to provide an inexpensive automatic bomb, preferably devoid of explosives or expensive timing mechanisms, for carrying, releasing and distributing the material whether it be granular or fluid, and insofar as possible the bomb is to be made of paper, inexpensive fabric and the like; it being understood that many of the materials to be thus distributed are themselves quite inexpensive.
In fire fighting, mono-ammonium-phosphate is frequentlyemployed either in a solution or as a crystal. The solution is favored where impact and natural winds are depended upon for It is therefore an object of the invention distribution although it is obvious that the crystal is more concentrated. It is an object of the invention to provide for the efficient distribution of granular or crystalline materials such as the aforesaid phosphate, or any of the other well.
known chemicals in such form that upon reach ing a heated zone will melt, vaporize, sublimate, or otherwise act to form a fire-extinguishing blanket of gas, vapor, fluid, slag or the like, although it will appear hereinafter that the invention permits of the distribution of water alone.
Many other objects of my invention will appear hereinafter and will be better understood by reason of the order in which they appear. In the accompanying drawing I have illustrated various devices for carrying out the invention and while the embodiments illustrated represent some forms which I prefer they by no means indicate a limit, the ensuing disclosure suggesting to the minds of persons skilled in the art numerous other ways of attaining the objects of the invention.
In the drawing Figure 1 is a View mainly in side elevation of one embodiment.
Figure 2 is a plan View thereof.
Figure 3 shows the device in operation.
Figure 4 is a plan view of the parachute.
Figure 5 is an elevation of a modification.
In carrying out my invention, the material to be distributed is placed within a container and launched in aerial flight or descent, as by being dropped from an airplane. Where the material is fluid or finely divided or granular it is readily separated fromthe container although where it might tend to adhere to the container suitable agitating means may be provided to loosen it at the proper time.
In any event the container is arranged so that it will travel rapidly, and it may be projected from a catapult or the like. Upon the container having fallen from a given elevation, or having been in flight for a given interval of time, a
differential is caused to be set up which results in the container being separated from the material and preferably retarded in flight or brought to a complete stop.- Then, preferably by acquired energy, the material is caused to spray itself over a wide area so that-in falling to the ground or surfaces above the ground it will be efiective over a wide area.
Inwhat I believe to be the simplest embodiment for use where the material is dropped from a known elevation and is of a form which readily detaches itself from the container, I provide an elongated tubular container having a weighted leading end, aerial fins, or the like, which cause it to remain with its axis perpendicular in descent. When the container has reached a given point above a fire, or above the ground, or above any zone to which the material is to be applied, the container is suddenly retarded in flight while a lower portion or the very bottom of the container is opened or allowed to be forced upon by the kinetic energy acquired by the detached material. One simple device for so retarding the container is a timed or delayed-opening parachute.
This need not be large as the container may be of paper or pasteboard and has little total weight. When the light-weight conline form of mono-ammonium-phosphate, for
example, air resistance will cause it to break into what appears to be a cloud of dust and the individual crystals will rain down over a wide area.
The same is generally true of fluids. However in some cases it is advisable to have slack strings or wires act to retain the bottom closure of the container in spaced relationship to the container to provide a distributor to better spray the material. Again where the material is not readily dislodged from the container or is of a nature to become packed in the container, I provide that movement of any part such as the parachute or the bottom closure relative to the container, during ejection, may move fingers or other agitating means thru the material and thus loosen it.
The formshown in Figures 1, 2 and 3 is most simple and in this embodiment the container is indicated at 8 and is merely a paste-board tube which may however be several inches in diameter and two or more feet in length, although larger or smaller sizes may be employed.
This container is provided at'the upper end with a simple square of cloth ll forming a parachute attached thereto by the shroud lines lli.
' The container is open at the lower end but this lower end is fitted with a readily detached closure or plug l l which forms a leading end for the bomb. The closure may be weighted or may be of the simplest light-weight construction as required, and is preferably so lightly fitted in place that the slightest retardation of the container will cause it to be dislodged, although in shipping and handling it is held in place by the clips it.
The parachute may be of any fabric or even stout paper and is folded along the lines indicated by the numeral it to bring the comers it to the center. first-folded form in which it is shown in Figure 4; it is provided with reinforcements It; iii, etc.. in the form of thin rigid strips which may be oi; thin wood, corrugated paper or the like.
Regarding the chute in this.
These are arranged to radiate from the center of the parachute as shown and to extend to or slightly beyond the lines Hi.
The container is nearly filled l1 and should this material be fluid the plug ll with'the material should be of any usual water tight construction, such as that of an expanding cup, although easily dislodged when released.
After the chute is folded as shown in Figure 4, the external reenforcements are moved into parallel relationship to the container as shown in Figure 2; these strips jointly forming a polygonal sheath around the container and being hingedly arranged by reason of being riveted, glued, or otherwise secured in place on the parachute fabric. Each is shown provided with a normal projection I8 which forms a fin or vane to guide the device in vertical descent.
When the strips I6, l6, are so disposed there remains a space 20 between same and the container in which the resultant folds of the parachute are disposed so that the parachute is totally enclosed and protected by these strips. The strips form a. sheath of slightly increasing diameter downwardly so that each strip becomes an airfoil having a slight angle of attack in vertical descent.
The strips are yieldably locked in this position with fingers l2 projecting from each strip to support the closure l I in position, although these fingers preferably require little or no energy for their release.
To yieldably hold the strips or airfoils in position, any suitable means may be employed, the drawings showing a simple elastic loop 22 fitted around the assembly'near the upper ends as by being stretched over the fins. This loop may be a rubber-encased spring with a definite tension or may be a selected. rubber band. The exact position and tension determines the "timing" of the device and this is therefore subject to accurate predetermination.
When the folded device shown in Figure 2 is launched it falls perpendicularly and acquires great speed. As it falls each "airfoil" is reacted upon by relative wind and produces for any speed a precalculated lift approximately normal to its plane. Thus the strips or airfoils tend to spread out or open up during descent. When 7 the device has fallen a given distance and has acquired a given speed, this reaction overcomes the tension of the loop 22 and the airfoils begin to spread while hinging at their upper ends. Now the elastic loop is stretched and is so elevated with respect to the hinge points of the airfoils that it finally acts to assist in spreading same although at the same instant it may be entirely dislodged.
All this takes place almost instantly when a given speed is reached and the parachute snaps open quite suddenly. Now the closure H is unsupported and when the parachute becomes effective the material in the container exerts no weight on the parachute and the parachute is opposed only by the slight mass of the container itself. Thus the relatively large parachute will quickly retard the container and in fact the peculiar reaction is often such that the tube or container is actually brought to a stop.
Now the objects of the device have been largely attained for the bottom is wide open insofar as escape of material is concerned, and the many pounds of material continue to travel at practically uninterrupted speed, which may be more than several hundred feet per second. Infect 33 pounds of such material falling from more. than 1000 feet will have the energy equal to one horse power operating for one minute. When material such as phosphate crystals are ejected into the atmosphere .with such acquired velocity, and with aaoasai no container to constrain them, they will, by reaction of the static air, spread over awide area, although each individual crystal will have sufficient downward trend to keep it from being blown too far away by prevailing winds.
In this way the container is opened with considerable accuracy a given point above a fire, for example, not so .close but that the material is well sprayed over a large area and yet not so far away as to allow prevailing winds or thermals to interiere.
Of course there are a great many other arts to which this device can be applied, particularly since it includes an accurately timed parachute devoid of explosive charges, moving parts and the like. Where the material is of a nature which will not spread suitably, I provide, as shown in Figure 5, that the plug it: be attached by long string it so as to remain under the container to act as a spreader. tainer may be fitted with the internal agitators 21 carried by either the parachute or the plug and here shown as carried by the plug.
it will be apparent now that I have provided for proiecting a constrained mass of material in aerial flight and forits timed separation from the container while still above the surface to which the material is to be applied, and for then spreading the material as required.
1. The hereindescribed method for fighting tires from the air which consists in dropping a receptacle containing a mass of extinguishing material from an elevation above the fire, constraining the mass during a part of the fOllOWiIlg aerial descent to allow same to acquire considerable velocity, and then suddenly retarding the receptacle while releasing the constrained mass thereby promoting its dissemination over a wide area by its reaction against the relatively static air of the atmosphere.
2. m a parachute device, a central body having a vertical axis, a plurality of vertical airfoils arranged parallel to said body and each hinged at the upper end relative thereto and forming a sheath around said body, a parachute fabric attached to said body and disposed in spaces between said airioils and said body, and yieldable means responsive to a predetermined normal thrust of said airfoils acting to hold said airfoils parallel of said body until a predetermined airspeed shall have been acquired.
3. In a device of the class described, a tubular open-end container, a detachable closure fitted over the lower end thereof, a plurality of airfoils Also if conditions require the coneach hinged at its upper end relative to said body and each originally parallel to the axis of said container with its lower end adjacent said closure, means carried by said airfoils engaging said closure to temporarily retain the closure in position, and yieldable means responsive to a given normal thrust of said airfoils normally holding the airfoils parallel to said container.
4. In an aerial device for extinguishing fire, a container having an open lower end and adapted to contain a mass of fire extinguishing material which will spread out when aerially released, means associated withthe container for guiding it in axially vertical aerial descent, means responsive to air pressure developed when the container attains a predetermined air speed for suddenly retarding the container while in aerial descent, including a parachute attached to the container, and a detachable closure for said lower open end arranged to continue its descent together with the mass of material and thereby release said material due to the inertia of said mass of material and said closure, when the descent of the container is suddenly retarded.
5. In an aerial device for extinguishing fire, a container for enclosing a mass of fire extinguishing material which when aerially released will spread over a wide area, means responsive to air pressure developed when the descending container attains a predetermined air speed for suddenly retarding the speed of descent of the container, and means responsive'to said sudden retarding of the container for causing the material to continue its descent due to inertia and thereby become released from the container.
6. In an aerial device for extinguishing fire, a container having an open lower end and adapted to contain a mass of fire extinguishing material which will spread out when aerially released, means associated with the. container for guiding it in axially vertical aerial descent, means responsive to air pressure developed when the container attains a predetermined air speed for suddenly retarding the container while in aerial descent, including a parachute attached to the container; and a detachable closure for said lower open end arranged to continue its descent together with the mass of material and thereby release said material due to the inertia of said mass of material and said closure, when the descent of the container is suddenly retarded, and deflector means carried by said closure for spreading material discharging from the container.
RONALD N. ROBERTS.