US 3428037 A
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Feb. 18, 1969 L CAPRlOLO 'E1-AL 3,428,037
Feb. 18, 1969 CAPmOLO ETAL l 3,428,037
HIGH VELOCITY AIR GUN WITH FRANGIBLE VALVE TRIGGER MEANS Filed June 14, 1966 Sheet 3 ofm` Feb- 18, 1969 LYCAPRloLo ETAL 3,428,037
HIGH VELOCITY AIRl GUN WITH FRANGIBLE VALVE TRIGGER MEANS Filed June 14, 1966 Sheet 3 of 3 United States Patent Otice 3,428,037 Patented Feb. 18, 1969 3,428,037 HIGH VELOCITY AIR GUN WITH FRANGIBLE VALVE TRIGGER MEANS Igino Capriolo and Ugo Sacerdote, Turin, Italy, assignors to Fiat Societa per Azioni, Turin, Italy Filed June 14, 1966, Ser. No. 557,446 Claims priority, application Italy, June 21, 1965, 29,502 U.S. Cl. 124-11 2 Claims Int. Cl. F41b 1 1/ 06; F41f 1/04 ABSTRACT OF THE DISCLOSURE A high velocity gun for shooting birds at airplane windshields includes a barrel, a loading breech, a breech bolt, a reservoir `of compressed air, and a frangible valve arrangement between the barrel and the breech. The breech bolt includes a puncturing pin to puncture the frangible valve arrangement. The frangible valve arrangement includes a plurality of spaced parallel frangible discs forming therebetween air tight compartments which are maintained at varying pressures from the compressed gas reservoir. The pressures are in a sequential gradient so that puncturing one disc causes substantially instantaneous breaking of all discs.
The invention relates to shooting devices or guns for shooting irregular articles at high speed. More particularly it relates to such devices for use in carrying out ground tests for determining the strength of aircraft on impact with winged creatures such as birds.
Such tests generally consist in shooting bodies of winged creates such as birds at high speed against particularly vulnerable exposed parts of the fuselage, such as those parts made of transparent material. Tests of this kind are intended to reproduce the impact conditions at high flying speeds.
The present invention relates particularly to such devices in which the power necessary for shooting the body of the bird is supplied by compressed air from a tank.
An object of the invention is to provide a device of the above mentioned type which can supply high loading pressures so as to achieve the highest possible throwing speeds for the body of a bird.
A further object of the invention is to provide a highvelocity gun, more particularly for shooting irregularly shaped objects such as birds in impact tests, comprising a barrel with a loading breech at one end, a loading chamber being provided in the breech and connectable to a reservoir of compressed gas via a slow-action valve, a breech bolt coaxial with the barrel, the bolt having a striker mechanism and means for control thereof and the striker mechanism being operable to trigger the rapid breakdown of a frangible valve arrangement maintaining a pressure gradient between the reservoir of compressed gas and that part of the barrel wherein is located the obf ject to be propelled.
These and other objects of the invention will be clear from the following description, given with reference to the accompanying drawings which are by way of example and in which:
FIGURE l is a perspective view of a device according to the invention;
FIGURE 2 is a part-sectional perspective view of a detail of the device shown in FIGURE 1, and
FIGURE 3 is a longitudinal axial sectional view on an enlarged scale of a detail of the loading breech.
A shooting or gun device according to the invention comprises a loading breech 2 arranged at one end of a barrel in the form of a tube 19. At the loading end of the tube 19 a projectile, such as the body of a bird, for instance a chicken, is arranged for being thrown against the material to be tested. A laterally arranged compressed air reservoir tank 6 is connected to the breech 2.
The breech 2 is provided at its forward end with a tubular extension 17 having screwed thereon a sleeve 17a which is provided with a terminal ilange 8 engageable in a sleeve 18 connected to the tube 19.
The breech is formed coaxially with the bore of the barrel or tube 19 and is provided with a longitudinal tubular body 3a coaxial `with the barrel and having a forward flange sealingly secured in the breech 2 with packings 3b.
Between the tubular body 3a; and the outer wall of the breech 2 there is formed an annular clearance 30, 31 which provides space for slidably mounting a tubular body 4 having a flange 27 acting as a piston in the clearance.
The ange 27 subdivides the clearance 30, 31 into two chambers 30 and 31, each of the chambers being connected with the other by means of pipes 29, 28. The pipes open into a pneumatic distributor 9- which is provided with an operating lever 9a, and is supplied with compressed air from a pipe 9c. A discharge pipe 9d is also pro-vided for the distributor 9.
As the piston ange 27 is an air-tight iit in the clearance 30, 31 the supply of compressed air to either of the chambers 30 or 3-1 effects axial sliding of the body 4 within the hollow in the breech.
The hollow breech interior is laterally connected to the compressed air reservoir 6, such connection with the breech being by means of a llanged connection 6a. This interconnection of the hollow of the breech and the reservoir 6 is via a valve arrangement comprising the body 4. The latter serves to fully close this interconnection when its end collar 4a is driven against the forward wall 23 of the breech.
A breech bolt 1 is slidingly mounted coaxially with the tubular body 3a and is adapted to be releasably secured by a bayonet joint arrangement into the body 3a. For this purpose radial wings 1a are arranged to engage suitable recesses provided in the flange 3I on the body.
The breech bolt 1 is provided at its inner end with a planar wall 1b which wall supports, by means of sealing connections 32, the rod of a striker 5 which is provided at its leading end with a striker pin 5a.
The striker is operated by resilient means 16 in the form of a helical spring or springs coaxially arranged around the rod at the section thereof between the striker pin 5a and the wall 1b of the breech bolt.
The section of the rod 5 lying on the other side of the wall 1b is guided by a support 33 and is provided with a projection 34 which is adapted to cooperate with a cocking device. This device comprises an arrangement of levers 14 articulated to one another and adapted to be actuated by the movable armature 13a of .an electromagnet 13. One lever is formed with a projection 35 which is adapted to engage the projection 34 on the striker in its cocked position. In such a position the spring 16 is of course tensioned. This arrangement causes the striker to snap forward when the electromagnet is energized on operation.
The cooking device is moreover provided with a mechanical safety catch in the form of a lever .15 for preventing undesired operation of the release projection 35.
To prepare for loading of the device according to the invention, the breech bolt 1 is removed from its seat by means of one or more handle levers 26. The device is then loaded by inserting at the loading end of the tube 19 a projectile in the form of the body of a bird 22 wrapped in a pad of weldable material. A wad 25 is placed behind the projectile 22 to improve sealing of the projectile in the barrel tube 19.
YA pluralityof diaphragms 7 are interposed in the cylindrical extension 17 of the breech and between the wad and chamber 24 into which the compressed air reservoir 6 opens. These diaphragms comprise very thin plastic discs, each about 0.07 mm. thick. The discs are maintained uniformly spaced by a plurality of circular rims 21 provided with seals and interposed between the individual diaphragms. A spacer 21a is interposed between the last diaphragm and the wad 25.
The diaphragms subdivide the space between the chamber 24 and the -wad 25 into a plurality of compartments 7a, 7b, 7c, 7d, 7e which compartments are each loaded with compressed air through pressure reducers 11 fed from a conduit 20 which is branched from the main tank 6 via a cock 10.
The pressure reducers are each connected to one of a number of pressure gauges 12` on an operating panel 12a and are adjusted to maintain the various compartments conned by the diaphragms 7 at different pressures, these pressures, decreasing towards the mouth of the tube 19.
In order to effect shooting, communication is established between the loading chamber and the tank 6 by withdrawing the valve-acting tubular body 4. This is achieved by suitable control of the air pressure in the delivery slide 30, 31.
By subsequently releasing the striker release device, explosive breakage of the iirst diaphragm 7 is effected, and this results in an increase in pressure on the next diaphragm, which is in turn broken. This chain reaction continues until there is explosive breakage of the last diaphragm, and this instantaneously interconnects the end of the tube 19 with the projectile 22 arranged therein, with the compressed air tank 6.
On explosive tearing, the diaphragms 7 act as quick opening valves effecting virtually instantaneous transmission of the pressure to the projectile so as to shoot it from the tube 19.
The projectile 22 thus suddenly receives the highest possible shooting pressure and is expelled at high speed through the tube .19.
It will be understood that various modications of the invention may be made within the scope of the appended claims.
What we claim is:
1. A high velocity gun, more particularly for shooting irregular objects such as birds in impact tests, the gun comprising:
(a) a barrel,
(b) a loading breech,
(c) a breech bolt,
(d) a frangible valve arrangement, and
(e) a reservoir of compressed air,
said loading breech being located at one end of said barrel and including a loading chamber and a slow acting valve arrangement which comprises a pneumatically controlled slide member disposed in one position to block the connection between said chamber and reservoir and in another position to open said connection whereby said chamber is connected to said reservoir, said breech bolt being arranged co-axially with said barrel and including a striker mechanism with a pointed part disposed to strike said frangible valve arrangement and operable to trigger the rapid breakdown of said frangible valve arrangement which, when whole, maintains a pressure gradiant between said loading chamber when connected to said reservoir and that part of said barrel wherein the object to be propelled is located, and a sealing wad interposed between the frangible valve arrangement and the object to be propelled in the barrel, the frangible valve arrangement including a plurality of frangible discs arranged transversely between the loading chamber and the wad, said discs forming therebetween a series of consecutive air tight cornpartments, the discs positioned by means of a plurality of sealing rims and at least one spacing element; the compartments formed by the spaced discs maintained at pressures such that said pressure gradient is created in sequentially positioned compartments, a valve controlled conduit between each compartment and said reservoir whereby the pressures for the pressure gradient are produced by the controlled supply of air under pressure from said reservoir.
2. A high velocity gun as claimed in claim 1 wherein said pressures for establishing the pressure gradient in the compartment are chosen such that penetration of said disc nearest said loading chamber by said pointed part of said striker causes substantially instantaneous breaking of all said discs.
References Cited UNITED STATES PATENTS 279,539 6/ 1883 Chamberlain 124-11 2,192,450 3/1940 Miller 124-11 2,304,841 12/ 1942 Mikkelsen 124-11 2,836,063 5/ 1958 Yoler 89-8 3,088,225 5/ 1963 Amistadi 124-11 FOREIGN PATENTS 405,645 1/ 1934 Great Britain.
ANTON O. OECHSLE, Primary Examiner.
R. W. DIAZ, 1R., Assistant Examiner.
U.S. Cl. X.R. 124-3 1