US3831520A

US3831520A - Biological bomb

Info

Publication number: US3831520A
Application number: US00727754A
Authority: US
Inventors: R Bowen; W Ford; R Sanborn; H Soini; B Lambert; W Sawyer; J Sharp; D Lull
Original assignee: US Department of Army
Current assignee: US Department of Army
Priority date: 1958-04-10
Filing date: 1958-04-10
Publication date: 1974-08-27
Anticipated expiration: 1991-08-27

Abstract

1. An aerosol bomb comprising an elongated cylindrical casing, a transverse wall in said casing having a rupturable diaphragm and defining a pressure chamber in the front end of said casing, said pressure chamber containing a compressed normally gaseous medium, a set of rotating tail vanes and a nozzle in the opposite end of said casing, a flexible sealed aerosol container within said casing adjacent said nozzle, penetrating means, within said casing, associated with said nozzle and adapted to penetrate said flexible container and conduct its contents to said nozzle, spring biased inertia means between said pressure chamber and said flexible container, said inertia means being held against the bias of the spring by means of centrifugally disengaging pawls, said inertia means serving to move forward, upon impact of the bomb, to penetrate said rupturable diaphragm and to release the gaseous pressure medium in the pressure chamber, said spring bias serving to force the inertia member in the opposite direction to impale the flexible aerosol container on the penetrating means whereby the released gaseous pressure from the pressure chamber serves to collapse said flexible container and expel its contents through the nozzle.

Description

ilnited States Patent [191 Bowen et al.

[451 Aug. 27, 1974 BHOLOGICAL BONE [75] Inventors: Russell J. Bowen, Boston; William B. Ford, ,lr., Winchester; Ralph D. Sanborn, Norwell; Winslow A. Sawyer, East Braintree; John R. Sharp, North Quincy; Herbert E. Soini, Hingham; Benjamin A. Lambert, Marshfield Hills; David B. Lull, Lexington, all of Mass.

[73] Assignee: The United States of America as represented by the Secretary 01 the Army, Washington, DC.

[22] Filed: Apr. 10, 1958 [21] Appl. No.: 727,754

[52] US. Cl. 102/6, 102/66 [51] Int. Cl. F42!) 25/12 [58] Field of Search 102/6, 1 S, 39, 90, 92,

[56] References Cited UNITED STATES PATENTS 2,128,433 8/1938 Rotheim 252/305 2,494,549 l/1950 Graumann 102/79 2,529,092 11/1950 Lodes 252/305 2,563,621 8/1951 Ritchie 252/305 2,617,359 11/1952 Van Horn et a1 102/92 2,698,215 12/1954. Peck 102/2 2,728,495 12/1955 Eaton 252/305 X 2,766,072 10/1956 Commarato 239/337 2,797,965 7/1957 McKemon 239/337 FOREIGN PATENTS OR APPLICATIONS 1,129,581 9/1956 France 102/6 Primary Examiner-Samuel W. Engle Attorney, Agent, or FirmEdward J. Kelly; Herbert Berl EXEMPLARY CLAIM 1. An aerosol bomb comprising an elongated cylindrical casing, a transverse wall in said casing having a rupturable diaphragm and defining a pressure chamber in the front end of said casing, said pressure chamber containing a compressed normally gaseous medium, a set of rotating tail vanes and a nozzle in the opposite end of said casing, a flexible sealed aerosol container within said casing adjacent said nozzle, penetrating means, within said casing, associated with said nozzle and adapted to penetrate said flexible container and conduct its contents to said nozzle, spring biased inertia means between said pressure chamber and said flexible container, said inertia means being held against the bias of the spring by means of centrifugally disengaging pawls, said inertia means serving to move forward, upon impact of the bomb, to penetrate said rupturable diaphragm and to release the gaseous pressure medium in the pressure chamber, said spring bias serving to force the inertia member in the opposite direction to impale the flexible aerosol container on the penetrating means whereby the released gaseous pressure from the pressure chamber serves to collapse said flexible container and expel its contents through the nozzle.

5 Claims, 3 Drawing Figures PATENTED EEQI @5201 lli/VE/VTORS Russell J Bowen Willa/w 8. Ford, JR. Ralph D; Samborn Win/0w A. Sawyer John R. Sharp Hwberf E Soini Bwjamin A. Lumber? flay/d B. Lu/l AT TORNE Y BIOLOGICAL BOMB This invention relates to an aerosol device. In particular, it relates to an aerosol bomb discharged upon contact.

There has been a long standing need for a small, air to surface missile intended for employment as an aerosol generator in the dissemination of water borne, biologically active agents. This missile primarily should be an anti-personnel munition for delivery against area targets by means of air borne clusters. Previous designs for pressurized mixture containers have not been found successful essentially for the reason that it is not desirable for the propellant and the biologically active agents to be pressurized in the same container. it is known that many biologically active agents are sensitive to variations in pressure, thus precluding the use of even the minimum pressures necessary for the known low pressure aerosols. Further, it is obvious that there is a greater danger of leakage in this latter type of aerosol and also an accidental set off would naturally result in far greater contamination of the environment with these agents when in a pressurized container than when in separate and independent containers from the propellant. It should be evident at this point that further problems would be encountered which involve effectively setting off the aerosol after being dropped from the air, as well as the propellant to be used to maintain a constant desirable aerosol spray. It is believed that the present invention proves itself to be a solution to these problems, and thus has the following objects.

The primary object of this invention is to provide an aerosol bomb that is safe in ordinary handling and activated solely upon sufficient minimum contact.

Another object of this invention is to provide separate closed containers for the propellant and the dispersed material and provide novel means for producing an aerosol spray.

Another object is to provide a novel means to restrain the arming of the bomb which is released only by rotation imparted during flight.

A further object is to provide novel container penetrating means activated by inertia movement of a container.

A further object is to provide a novel propellant composition.

A still further object is to provide novel means whereby the vapor pressure of the propellant is controlled within limits.

Further and more specific objects will be evident and a clear understanding of the invention will be had from the following detailed description and drawings.

In the drawing:

FIG. 1 is a top view of the assembled device showing the fin structure.

FIG. 2 is an elevation view in section of the preferred embodiment of the invention.

FIG. 3 represents the top plan view of platform 40 showing gas port holes.

The present invention is shown in a preferred embodiment to be composed of a body shown generally at 10. This body comprises a lower section 12 into which is snugly fitted a container ring 14 having an elongation adapter 16 screwed thereon and which receives at its upper end a collar 18. Fitted into the collar 18 is an upper section 20 which has disposed inside its uppermost portion a nozzle assembly 22. Secured to the upper and outer portion of the upper section 20 in a conventional manner are two pairs of fins, 24 and 26 respectively, which are of a wrap around spring steel type designed (1) to permit efficient packaging in a cluster, (2) to provide stability and a satisfactory terminal velocity in flight, and (3) to impart rotation for arming the device in a manner hereinafter set forth. This particular embodiment of the invention is designed to be 9.75 in. long, 1.5 in. diameter and weighs 1.6 pounds.

Disposed securely within the container ring 14 is a stationary container 28 for the propellant and may be of any suitable construction such as metal, plastic etc. able to withstand pressure. The container maybe covered and closed by a sealing diaphragm 30 made of rubber or the like. Above container 28, is an upper container 32 which holds the material to be dispersed such as the biologically active agents of the instant invention. Container 32 is constructed of a flexible impervious material such as rubber, polyethylene, etc. which enables a biologically active aqueous slurry contents to be squeezed out of an opening made therein by the exertion of a pressure on the outside of the container. Screw holding means 34 supports the container 32 and is in turn secured to an annular flanged ring 36 resiliently engaged by a barrel power spring 38 to a stationary platfrom 40 having a plurality of gas port holes 74 which permit the passage of the gaseous propellant from container 28 to the nozzle. Reciprocally fitted within a suitable opening in the platform 40 is a plunger 42 which terminates at one end in a blunt penetrating point 44. The plunger is of such length that point 44 is immediately above diaphragm 30. At its other end plunger 42 is fitted within the annular space of the annular flanged ring 36 and abuts the screw holding means 34.

Vertical movement of the plunger 42, and thus of the container 32, is prevented by a novel restraining means which comprises a pair of flyweight detents 46 urged by springs 48 into corresponding recesses 50 in plunger 42 to dog the plunger. Springs 48 are designed to be of such strength that the detents are urged into the recesses 50 until the detents are subjected to a sufficient centrifugal force that will compress the springs 48. In order to prevent any inward radial movement of the detents 46 when they have compressed their corresponding springs 48, pins 52 are provided in openings in the platform 40. These pins are engaged by the depending flange of the annular flanged ring 36 upon the latters downward movement subsequently described. Upon engagement by the flange, pins 52 are forced into an abutting relationship with an enlarged portion 54 of the detents 46, such that the plunger 42 will not be restricted in its reciprocal motion.

Disposed in the upper portion of upper section 20 is the nozzle assembly 22 which comprises ports 56 in fluid communication with annular gas passage 58 which surrounds a conically shaped feed tube 60, both of which discharge at nozzle 62. In communication with the feed tube 60 is orifice plate 64, having a sharp edged flow controlling orifice 66. A hypodermic needle 68, disposed below the orifice plate, is adapted to penetrate the top of the upper container 32 upon its upward movement to thus feed the contents thereof through the orifice 66 into feed tube 60, and to an ultimate discharge through nozzle 62.

The bomb contains several safety features such as pin 70 and pin 72 both preventing any movement of the plunger 42 until sheared off by the contact of the bomb with the ground.

The operation of the bomb is as follows.

At rest condition the bomb is unarmed in that the detents 46 engage the plunger 42 and prevent any movement thereof. Upon being dropped from the air, the

fins

24 and 26 cause the bomb to rotate about its long axis with sufficient radial velocity to produce the centrifugal force necessary for the detents 46 to compress the springs 48. The bomb is thus armed. When the bomb strikes the ground, the inertia of container 32 causes relative movement between the body and itself and compresses and energizes barrel power spring 38. This downward movement is designed especially to allow point 44 to penetrate diaphragm 30 and thus release the propellant in container 28 which passes through platform 40 by means of gas port holes 74, thereby entering upper section which houses container 32. Also upon the downward movement of the flange, annular ring 36 strikes the pins 52 which engage the enlarged portion of the detents 46 thereby dogging them in their outer armed position. The energized spring 38 then exerts an upward force on the container 32 which causes the latter to be impaled upon hypodermic needle 68 and remain there. The pressure of the propellant is such that the flexible slurry container 32 tends to collapse thus forcing its aqueous contents through the hypodermic needle 56 through orifice 66 into feed tube 60 and to discharge through nozzle 62. At the same time as the gas propellant causes the gradual collapse of the container 32, the gas is forced through ports 56 and annular passage 58 and is discharged with the aqueous biologically active slurry from the feed tube 60 through the nozzle 62 in a fine aerosol spray. The sizes of the nozzle and ports are such as to produce a free volume of gas to liquid slurry ratio of approximately 1200 to 1. Conventional nozzles may be used for this purpose.

The propellant suited especially for this particularly shaped and sized missile and for the operating condition expected to be encountered, viz., 35F 60F, aqueous slurry of approximately unit density and a viscosity of l to 50 cp at standard conditions, has been found to be propylene. Other propellants used in aerosol devices e.g., C l-l CO CH Cl, S0 and fluorochloro fluorinated hydrocarbons such as Freon ll (CFCl l2 (CF Cl 22 etc. have been tested, but all except CgHg had high storage pressures compared to propylene and propane. Propylene, due to its higher vapor pressure which produced better aerosol was found to be idea].

In order to maintain the desirable flow rate of l ml/sec and 2 CFM of gas and liquid respectively for a proper aerosol spray, as well as a pressure of at least 40 psig for proper container collapse during much of the operating cycle, it was found that the novel use of the latent heat of fusion of Water would prevent the temperature, and thereby the vapor pressure, of the liquid propylene from falling below a fixed level controlled both by freezing point of water and the rate at which heat can be transferred from the water to the propylene. The desired rate of heat transfer has been found to be obtained by absorbing the water on a finely divided fibrous material such as low density balsa wood splinters thereby providing a large area of contact between the two liquid phases. lt need hardly be stated that other finely divided solids may be used, eg asbestos, pine chips. However, due regard must be given to the density of the material so as not to effect an undesired weight increase.

A typical composition of propellant has been found to be 29.5 gm propylene, 22 gm water and 2.2 gm balsa wood sawdust.

lt should be noted that this device is not limited to two containers, but may have any number of them containing different propellants and/or different biologically active slurries, nor need there be only one nozzle, but rather a plurality may be used.

From the foregoing detailed description, it will be evident that there are a number of changes, adaptations and modifications of the present invention that come within the province of those skilled in the art; however, it is intended that all such variations in structure, modes of usage and materials be considered to be within the scope of this invention as limited solely by the appended claims.

We claim:

1. An aerosol bomb comprising an elongated cylindrical casing, a transverse wall in said casing having a rupturable diaphragm and defining a pressure chamber in the front end of said casing said pressure chamber containing a compressed normally gaseous medium, a set of rotating tail vanes and a nozzle in the opposite end of said casing, a flexible sealed aerosol container within said casing adjacent said nozzle, penetrating means, within said casing, associated with said nozzle and adapted to penetrate said flexible container and conduct its contents to said nozzle, spring biased inertia means between said pressure chamber and said flexible container, said inertia means being held against the bias of the spring by means of centrifugally disengaging pawls, said inertia means serving to move forward, upon impact of the bomb, to penetrate said rupturable diaphragm and to release the gaseous pressure medium in the pressure chamber, said spring bias serving to force the inertia member in the opposite direction to impale the flexible aerosol container on the penetrating means whereby the released gaseous pressure from the pressure chamber serves to collapse said flexible container and expel its contents through the nozzle.

2. A structure in accordance with claim 1 wherein said normally gaseous medium is a hydrocarbon.

3. A structure in accordance with claim 1 wherein said normally gaseous medium includes a heat of fusion supplying material combined with a finely dispersed solid whereby the vapor pressure of the gaseous medium is controlled.

4. A structure in accordance with claim 1 wherein said flexible aerosol container is made of a flexible polyethylene.

5. A structure in accordance with claim 1 including dogging means to hold said centrifugally disengaging pawls in disengaged position once they reach that stage through rotation of the bomb.