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Publication numberUS3381403 A
Publication typeGrant
Publication dateMay 7, 1968
Filing dateApr 7, 1966
Priority dateNov 24, 1961
Also published asDE1283120B
Publication numberUS 3381403 A, US 3381403A, US-A-3381403, US3381403 A, US3381403A
InventorsMurdoch Colin Albert
Original AssigneeMurdoch Colin Albert
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Means for use in the administering of drugs, medicines and the like to animals
US 3381403 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

May 7, 1968 c. A. MURDOCH MEANS FOR USE IN THE ADMINISTERING OF DRUGS MEDICINES AND THE LIKE TO ANIMALS 2 Sheets-Sheet 1 Filed April '7, 1966 IE v////// ///7//// r N f/ v////vw Q flu w nnn i--. i w l! y 1968 c. A. MURDOCH 3,381,403

MEANS FOR USE IN THE ADMINISTERING OF DRUGS, MEDICINES I AND THE LIKE TO ANIMALS 2 Sheets-Sheet 2 Filed April 7, 1966 United States Patent 3,381,403 MEANS FOR USE IN THE ADMINISTERING 0F DRUGS, MEDICINES AND THE LIKE TO ANIMALS Colin Albert Murdoch, 14A Hassal St., Timaru, South Island, New Zealand Continuation-impart of application Ser. No. 238,412, Nov. 19, 1962. This application Apr. 7, 1966, Ser. No. 540,953 Claims priority, application New Zealand, Nov. 24, 1961, 130,784; Aug. 13, 1962, 132,777 Claims. (Cl. 42-1) ABSTRACT OF THE DISCLOSURE A projecting unit for projecting a projectile in which a housing defining a gas expansion chamber defining means is carried by a supporting means and is in communication with a charge receiving chamber with a barrel on the housing being in communication with the gas expansion chamber. Valve means provided between the gas expansion chamber and the valve and adjusting means operably connected with the valve means serves for con trolling the valve means movement to a predetermined degree whereby the volume of gas passing from the expansion chamber to the barrel at the rear of the projectile in the barrel upon detonation of the charge may be controlled in order that the velocity and/or range of the projectile leaving the barrel may be varied.

This application is a continuation-in-part of my prior filed application, now abandoned, Ser. No. 238,412, filed Nov. 19, 1962, and entitled Means for Use in the Administering of Drugs. Medicines and the Like to Animals.

This invention relates to a projecting device or weapon for use in propelling projectiles of various velocities and for various ranges with a minimum of noise and maximum accuracy. Such a weapon is particularly intended for use in the administering of drugs, medicines and the like to an animal, which is situated at a distance from or is unapproachable by a person desiring to administer the drugs. Such drugs are contained within syringe projectiles and upon impact with the skin of the animal the syringe injects the drug, etcetera into the animal. Other substances such as liquid dye may be provided within the projectiles which are dispersed on impact with the animal by a small detonator contained in the construc tion. Alternatively an identity tag or the like may be attached to an animal by means of a projectile projected from such a weapon.

It is an object of the present invention to provide a projecting device or weapon such as a rifle or pistol designed to fire an explosive ballistic cartridge blank to provide propulsive power in the form of explosive gases, which by means of a pro-expansion chamber or chambers and valving means capable of controlling the actual gas pressures finally directed to the barrel or breach area in which the projectile is situated, the projectile may be propelled at a range of initial velocities suitable for desired distances and terminal impacts for embedding the projectile into an animal without injuring it and at the same time in producing a minimum of noise from the explosion.

Another object of the invention is to facilitate the greatest range of application to the widest possible variety of animals by the provision for the interchanging of barrels of various calibres to take a variety of projectiles of various sizes.

A further object of the present invention is to provide a means of gas control in the projecting device or weapon.

whereby pre-setting against graduations provided for this purpose enables the operator of the device to adjust the gas pressure at will to enable him to achieve a desired range and a desired degree of impact, with the weapon and a projectile of his choice.

A further object of the present invention is to provide a method of adjusting the gas pressure in the projecting device such that minimum pressures are provided at one extreme of the velocity control movement providing a minimum range of a few feet only and consequently almost no energy of impact, through to the other extreme of the control movement to a maximum pressure of propulsion which is capable of sending a projectile a distance of hundreds of yards.

The various known constructions of projecting devices or weapons providing variation of the propelling force explosive charge to vary the range of the projectile, all have a disadvantage that the gases of the explosion are directed behind the projectile and the gas impact is violent when contacting a projectile. Provision of side gas escape ports through which part of the propelling force is bled off to vary the range potential is known, but none of the known arrangements is suitable -for the purpose of projecting the projectiles mentioned. above.

Other known projecting devices or weapons make use of the explosive gases after the projectile has been given maximum forward thrust and the work of the explosive gases is finished in order to operate the reloading mechanism to create an automatic reloading weapon.

Accordingly, the present invention provides a projecting device or weapon for projecting a projectile comprising supporting means, a housing constituting a charge receiving chamber carried by said supporting means, a gas expansion cham'ber defining means carriedby said supporting means and being in communication with said charge receiving chamber, a barrel mounted on said supporting means and being in communication with said gas expansion chamber, said barrel being adapted to receive 'the hypodermic projectile, and control means for said gas expansion chamber located exteriorly of said gas expansion chamber, said control means including a cylinder having an open end adapted to communicate with said gas expansion chamber, a valve seat for said open end of said cylinder, a valve head co-opera-ble with said seat for opening and closing the seat, a valve stem for said valve head extending axially of the cylinder, spring means co-operab-ly associated with said stem and cylinder normally holding the valve head on the seat, and adjusting means operably connected with said stem for moving said valve head away from said seat to a predetermined degree to enlarge the capacity of said gas expansion chamber so that upon detonation of the charge in the charge receiving chamber, the pressure of the gases produced thereby will be reduced in the gas expansion chamber whereby the velocity of the hypodermic projectile leaving the barrel may be varied.

Moreover, the present invention prov-ides a projecting device or weapon for projecting a projectile comprising supporting means, a valve seat for said open end of a cylinder, a valve head co-operable with said seat for opening and closing the seat, a valve stem for said valve head extending axially of the cylinder, spring means cooperably associated with said stem and cylinder normally holding the valve head on the seat, and adjusting means operably connected with said stem for moving said valve head away from said seat to a predetermined degree to enlarge the capacity of said gas expansion chamber so that upon detonation of the charge in the charge receiving chamber, the pressure of the gases produced thereby will be reduced in the gas expansion chamber whereby the velocity of the hypodermic projectile leaving the barrel may be varied, and means for variably adjusting the volume of said cylinder, with said variable adjusting means being defined by a piston axially movable relative to said cylinder.

Furthermore, the present invention rovides a projecting device or weapon for projecting a projectile, comprising supporting means, a housing constituting a primary gas expansion chamber defining means carried by said supporting means being in communication with a charge receiving chamber, a barrel mounted on said housing and being in communication with said primary gas expansion chamber, said barrel being adapted to receive a projectile, a secondary gas expansion chamber in communication with and forming an extension of the primary gas expansion chamber and valve means provided between said two gas expansion chambers, adjusting means operably connected with the valve means for controlling movement of said valve means to a predetermined degree to control the degree of communication between the gas expansion chambers and thus control the volume of gas interchanging between the gas expansion chambers upon detonation of the charge in the charge receiving chamber and thus controlling the pressure of the gas passing from the primary gas expansion chamber to the barrel at the rear of the projectile whereby the velo'city and/ or range of the projectile leaving the barrel may be varied.

Furthermore, the present invention provides a projecting device or weapon for projecting a projectile, comprising supporting means, a housing constituting a gas expansion chamber defining means carried by said supporting means and being in communication with a charge receiving chamber, a barrel mounted on said housing and being in communication with said gas expansion chamber, said barrel being adapted to receive a projectile, valve means provided between said gas expansion chamber and barrel adjusting means operably connected with the valve means for controlling movement of the valve means to a predetermined degree to control the volume of gas passing from the gas expansion chamber to the barrel at the rear of the projectile upon detonation of the charge in the charge receiving chamber whereby the velocity and/ or range of the projectile leaving the barrel may be varied.

The projecting device or weapon according to the invention includes a cartridge breach and firing mechanism arranged to accommodate and discharge a blank cartridge as desired and a stock or butt to facilitate the holding of the weapon still for accurate shooting, etc. A gas passage from the cartridge breach, where the explosion takes place, to a gas expansion chamber of particular capacity where-in the first function of controlling the force of explosion is undertaken, is also provided. The capacity of this chamber will depend upon the possible maximum range potential required and the load of explosive designed for the particular weapon concerned to give full variation of application required with the weapon. The velocity and direction of gas particles formed by the explosion are also adjusted to change them from a damaging force capable of distorting or damaging the projectile in the projectile breach and by so doing rovide a controlled force or propulsion which will function with maximum efiiciency for this particular purpose.

The gas produced by the explosion in all settings of the valve means is harnessed to provide the desired degree of thrust and the expansion of the gas in the expansion chamber dictates the total pressure created depending upon the setting of the valve control, and because projection of the projectile is obtained by the gas pressure for the full length of the barrel continued emission of the gas is necessary to maintain the velocity of the projectile as it leaves the barrel.

Conventional weapons provide a transfer of forward thrust caused by the explosion and create a degree of momentum which carries the projectile from the barrel 4 but at a constant high velocity, Whereas the Weapon of the present invention at minimum settings the projectile is pushed along the barrel at a constant speed until it leaves the barrel and then due to this initial momentum carries on tor the required distance.

In several embodiments of the invention primary and secondary gas expansion chambers are provided whereby the primary gas expansion chamber total volume is such that when the secondary expansion chamber separated from the primary by a valve restricts the total expansion to that only of the primary expansion chamber as when the valve is closed to the secondary expansion chamber, the total pressure produced by the explosion is such that the maximum pressure created within the chamber is adequate to provide maximum range capacity for the desired projectile.

The cartridge used may contain an explosive load which, if directed behind a solid projectile, such as a conventional bullet and in a conventional barrel bored to take the bullets like any conventional firearm, then the explosive force produced by detonation of this charge would be equal to the pressures produced by a high velocity high pressure cartridge of conventional nature. Pressure may be in the order of 20,000 to 30,000 lb. per square inch, but however in the projecting device or weapon of the present invention although this force is actually potentially there in full, by the relationship of gas expansion prior to taking it to the projectile breach area where it is put to work, it is reduced from 20,000 to 30,000 lb. per square inch to a pressure of something in the order of 2,000 lb. per square inch maximum, this being the maximum pressure likely to be required for the projectile being used and capable of providing the full range requirements of the application it is put to. Furthermore, by the provision of a valve which may for example permit partial communication of the explosion gases to the secondary expansion chamber or if required full communication to this chamber to reduce the total pressure to a minimum working force of perhaps less than 50 lb. per square inch, variation in the propelling force provided by the gas is possible and subsequently a variation over a considerable range of potential projectile velocity.

In another embodiment of the present invention a pri mary gas expansion chamber is provided which is variable in its volume, such variation in volume is obtained by means such as a piston movable axially within the chamber. Thus by varying the position of the piston, the volume of the gas expansion chamber can be varied before detonating the charge to reduce or enlarge the capacity of the chamber and thereby the pressure and velocity of the gases impinging on the projectile in the barrel.

In yet another embodiment of the present invention which in this arrangement is applied to a pistol form of weapon which is more manageable and of lighter weight but nevertheless capable of long or short effective ranges, a control for the gas is provided consisting of a primary gas expansion chamber only. This arrangement has instead a valve operated over the gas passage from the primary gas expansion chamber which leads to the projectile breech and barrel. This valve can create the same overall effect in that the actual pressure being produced in the expansion chamber will be such that it is safely contained within the chamber which will now act as a reservoir at the time of discharge to hold the gases under pressure and by adjusting the valve only that volume of gas which is desired will be allowed to enter the projectile breech and consequently only a desired projectile velocity may result. The principle is still the same as the previously described embodiments in that a controlled gas pressure is being provided by an explosion of a cartridge containing a definite load of explosive and the gases produced are utilized at will to provide the precise propulsion pressure needed for a desired range potential. The damaging velocities of the explosive gases have been removed and after processing are now converted to a useful force of propulsion which will not endanger the projectile by damaging it .by the explosive forces should direct contact be made with the projectile as in conventional weapons.

The heat of the explosion is removed prior to allowing the gas to reach the projectile barrel and in addition the noise by this process is muffled and reduced to silence the report.

Variation in the rate of the combustion of the explosive is produced byvarying the restriction or expansion permitted of the gas from the explosion.

Super-heating which greatly increases the gas potential pressure when the gases are restricted in expansion by being contained in a small space which brings the gas molecules closer together during the period of production when heat is extremely high, will vastly add to the total or potential pressure produced. If the gases are allowed to expand to a greater and greater extent by providing this variable space of expansion as is done in the projecting device of the present invention, then this pressure must substantially flatten or reduce since the proximity of the heated molecules must be greater with more room to expand. The closer the molecules together 'when heat is maximum the more quickly each will heat the next one and the greater the overall pressure, while conversely the larger the space between the molecules the lower the rate of heating and the lower the total heat and pressure.

The concept of a weapon to propel a syringe projectile is such that the actual velocity of the projectile should be decidedly low to prevent the projectile syringe passing clean through the animal intended to be injected. Similarly it is a feature of the present invention that the speed of the projectile by being variable may also be coupled with the trajectory angle to enable actual variation of impact at any range to allow small animals to be injected without injury and using the same weapon and syringe projectile increase the impact and hence penetration to enable the needle to penetrate the hide of a rhinoceros with equal achievement of purpose.

The projectile device or weapon of the present invention also provides the possibility of interchanging the barrels of the weapon. The locking type breech of this weapon in which the barrel is fitted with a pad in the form of a segment of a circle on the outer surface of the barrel to locate in a recess cut away from the barrel sleeve into which the barrel is to be inserted enables the barrel pad to rotate into the recess from the top. The pad is also capable of being moved longitudinally up and down the sleeve to enable access to the breech, as well as facilitating the sliding of the barrel from the barrel sleeve when it has been taken from the main frame of the weapon.

In order that the invention may be more readily described preferred embodiments thereof are described below in conjunction with the accompanying drawings.

FIGURE 1 is an elevational view of the one form of the projecting device,

FIGURE 2 is a view in longitudinal cross section of one form of the projecting device,

FIGURE 3 is a view in cross section taken on line III-III in FIGURE 2, the view looking in the direction of the arrows,

FIGURE 4 is a fragmentary view partly in elevation and partly in cross section of a modification of the projecting device,

FIGURE 5 is a view in cross section taken on line V-V in FIGURE 4, the view looking in the direct-ion of the arrows,

FIGURE 6 is a fragmentary view in longitudinal cross section of a further form of the projecting device,

FIGURE 7 is a view in cross section taken on line VIIVII in FIGURE 6, the view looking in the direction of the arrows,

FIGURE 8 is a fragmentary view in longitudinal cross section of yet another form of the projecting device,

FIGURE 9 is a plan view of the barrel and barrel sleeve shown in FIGURE 8, and

FIGURE 10 is a fragmentary view in longitudinal cross-section of a further form of the projecting device.

In one form of this invention illustrated by FIGURES 1-3, the projecting device is in the form of a gun and has a supporting stock generally indicated 1 which may be of standard form and construction having a butt portion 2 extending into a grip portion 3, the grip portion further extending into a bed portion 4 arranged to receive and support charge loading means 5 and charge chamber housing 6.

The charge chamber housing 6 is an elongated member such as for example a cylindrical housing bedded on and secured to the stock 1 and more particularly secured to the bed portion 4 of the stock 1 with the housing 6 being disposed in substantially parallel relationship with the bed portion 4.

Gas expansion chamber housing 7 secured relative to the stock 1 and the housing 6 is situated below and forward of and disposed in parallel relationship withthe housing 6. The attachment of the gas expansion chamber housing 7 relative to the stock and the housing 6, for example, can be obtained by means of a mounting member 8 secured to and projecting downwardly from the housing 6 and mounted in a substantially forward position of the housing 6, with such mounting means 8 being common to the housing 6 and the housing 7. A charge chamber 6a is situated in a position convenient to the charge loading means 5 and the firing mechanism (not shown) and from the forward end of the charge chamber 6a (FIGURE 2) there extends a passage 9 through the mounting means 8 leading from the charge chamber 6a to a gas expansion chamber 7a.

In this preferred form of the invention, a barrel I0- is mounted in front of and is co-axial with the charge chamber housing 6.

By means of the gas expansion chamber, the initial force of the detonation of the charge in the charge chamber housing is reduced thereby allowing the projectile in the barrel to accelerate slowly from its rest position at the rear of the barrel, thereby ensuring that the projectile Will not become distorted in the initial stages of its projection.

Furthermore, the gas expansion chamber is a means whereby there is provided a cushion of air between the charge in the charge chamber housing and the projectile in the rear of the barrel for the further purpose of ensuring that the projectile is not damaged due to the heat and high velocity of the gases created by the detonation of such charge in such charge chamber housing.

In accordance with this invention the gas expansion chamber 7a may be provided with bafiies, positioning means or spacing members 12.

The housing 7 is a hollow cylinder and is provided with a gas duct 11 situated within and co-axial with the gas expansion chamber 7a of the housing 7, with the external diameter .of the gas duct 11 being substantially less than the internal diameter of the gas expansion chamber housing 7 for the purpose of enabling gases to pass between the housing 7 and the gas duct 11. A rearward end 11a of the gas duct 11 communicates with the charge chamber 6a by way of the passage 9 and forward end 11b of the gas duct 11 terminates short of forward end 7b of the housing 7 to allow the discharge of gases into the gas expansion chamber 7a. The gas duct 11 may be positioned co-axially of the gas expansion chamber 7a by means of the bailies, positioning means or spacing members 12 through which the gas duct 11 passes and is held by such members 12 in a co-axial position with relation to the housing 7 as aforesaid. The gases may impinge on the members 12 and thereby be disturbed for producing a desired mufiiing effect of the noise created by the detonation, in the charge chamber 6a of the charge, for the purpose of projecting the projectile.

A gas exit port 13 is situated in the wall of and at rear end 7c of the housing 7 and leads to rear portion 16a of the barrel 10 by way of a gas exit passage 13a.

By this arrangement, the gases created by the detonation of a charge in the charge chamber 6a are led to the rear end 11a of the gas duct 11 through the gas duct 11 and are discharged from the forward end 11b thereof into the gas expansion chamber in. The gases are then passed along the gas expansion chamber 7a confined by the external surface of the gas duct 11 and the internal surface of the housing 7, with the passage of the gases being disturbed by the members 12 upon which members 12 the gases impinge for the purpose above mentioned. The gases are led from the gas expansion chamber 7a to the rear portion 10a of the barrel 10 through the gas exit port 13 and along the gas exit passage 13a formed in the mounting member 8 and connecting the gas exit port '13 with the rear portion 10b of barrel 1d.

The present projecting device is constructed and arranged to project a projectile such as, for example, a projectile hypodermic syringe of the kind described in my co-pending application Scr, No. 23,448 filed Nov. 14, 1962 and now abandoned. The purpose of such hypodermic syringe when fired is to inject and thereby administer drugs and the like into an animal when the needle penetrates the flesh of the animal The gas expansion control means in one form of the invention (see FIGURE 2) is a hollow cylinder 15 mounted co-axially of and in front of the housing 7 and is divided from the gas expansion chamber 7a by a valve housing 16 which contains a valving means indicated at 17 operable and adjustable by a valve adjusting means indicated at 18. The valve housing 16 also forms a conjoining member for the cylinder 15 and the housing 7, and a finger control 18a of the valve adjusting means 18 forms a closure for the forward end of the cylinder 15.

The cylinder 15 may be opened to the expanding gases created by the detonation of a charge in the charge chamber by an adjustment of a valve 17a of the valving means 17 with relation to a valve seal 171) with such adjustment being effected by operation of the valve adjusting means 18. This is for the purpose of reducing the gas pressure in the gas expansion chamber 7a by means of effectually enlarging the capacity of the gas expansion chamber 7a. By this arrangement, the velocity of the projectile when projected through the barrel 10 is varied. Thus, by varying the aperture between the valve 17a and the valve seat 1717 a variation in the velocity of the projectile may be obtained and in this way the operator may ensure that the projectile is travelling at a desired speed to enable the projectile to perform its function, without injuring the animal due to the velocity of such projectile being too high, over a variation of the distance between the projecting means and the animal to be hit.

Furthermore, the present projecting device may be provided with sighting means 19 which may be in the form of standard back and forcsights or may be in the form of a telescopic sight which may be attached to the housing 6 in a position convenient to a user.

It is a further object of the ga expansion control means 15 in association with the valving means 16 to provide means whereby the sighting means 19 may be fixed to the projecting means and the accuracy of the projecting means over varying ranges may be obtained by varying the velocity of the projectile as aforesaid, thereby varying the trajectory of the projectile. The valve 17a of the valving means 17 is of the poppet type and is operated by the valve adjusting means 18.

The finger control 18a comprises a threaded cap which also forms a closure for the forward end of the control means cylinder 15, a valve operating rod 181) and a valve spring 18c, and operates the valve 17a by Way of the rod 1815 which passes through the axis of barrel of the cylinder 15. The valving means 17 is constructed so that, in the case of gas pressure differential in favor of the cylinder 15, the excess gases in the cylinder 15 may Cal pass to the gas expansion chamber 7a by opening the valve 17a against the pressure of the valve spring 180. The valve operating rod 181) is slidably held into the cap 18a by means of the valve spring 180.

An alternative construction of the control means may provide means whereby the control means cylinder 15 may be variable in its volume. Such a variation in volume is obtained by means such as a piston 25 (see FIGURE 4) movable axially within the body of the cylinder 15 which may be slidably positioned Within and keyed against axial rotation with relation to the body of the cylinder 15 by a keyway 15:: formed in the cylinder 15 and a key 25a formed on the piston 25. Thus, by varying the position of the piston, the volume of the space in which the gases can expand before ejecting the projectile may be varied thus reducing or increasing the velocity of the gases and thereby the velocity of the projectile as desired. The piston 25 may have a coarsely threaded axial bore 25b provided therein and the rod 181; may be provided with a corresponding thread 18d and be adapted to be engaged with the thread bore 25b of the piston 25. The rod 18b may be held against rotation with relation to the piston adjusting means 18 by a spigot 26 with such piston adjusting means 18 corresponding to the valve adjusting means of the preferred form of the cylinder 15 as hereinbefore described. Thus, by this arrangement upon the operation of the piston adjusting means 18 the threaded rod 181) is rotated and consequently effects an axial adjustment of the keyed piston 25 in the bore of the cylinder 15. A variation of the volume of the cylinder 15 is thereby obtained.

In another form of this invention (not shown), the gas exit port is situated at the forward end of the gas expansion chamber housing and gases may be led from the gas expansion chamber to the rear of the barrel by means of a separate passage disposed between the barrel and the gas expansion chamber which may lead the gas in a substantially parallel but reversed direction to that direction of the gase in the gas expansion chamber to the rearward end of the barrel. The gases may be led from the charge chamber to the rearward end of the gas expansion chamber housing and into the gas expansion chamber.

A trigger 20, the charge loading means 5 and a firing mechanism (not shown) associated with the stock 1 and the housing 6 may be a standard construction as used in orthodox firearms or guns such as rifles and pistols. The trigger 20 is arranged to actuate the firing mechanism, with such firing mechanism being arranged to detonate the charge when such charge is in the charge chamber 6a. The charge used may be an explosive charge such as cordite encased in a carrier or case having its dimensions in accordance with the dimensions of the charge chamber 6a.

The stock 1 as described, may be provided with the charge loading means such as a bolt (not shown) provided in a slidable engagement with the stock 1 and which is operable to displace a charge from a magazine (not shown) holding a plurality of charges and feed one charge into the charge chamber 611.

In using the form of the improved projecting device shown in FIGURES 2 and 3, the magazine is charged with a desired number of cordite charges and the projectile such as for example a projectile hypodermic syringe is inserted in a breech 22 provided in a barrel supporting means 23 and the barrel 10. Subsequently when it is desired to project the syringe towards an animal, the charge (not shown) is displaced from the magazine by the charge loading means and placed in the charge chamber 6a and on sighting the projecting device upon the animal and actuating the trigger 20 to bring into operation the firing mechanism, the charge detonates thus producing gases under pressure which expand and pass at high velocity along the passage 9 and gas duct 11 leading such gases to the forward portion 712 of the gas expansion chamber housing 7 and into the gas expansion chamber 7a wherein the noise of the detonation is reduced to a minimum by the impinging of the gases on the members 12 before such gases pass and are led to the rear end a of the barrel 10 and act upon the hypodermic syringe to expel such projectile syringe from muzzle end 1022 of the barrel 10 and toward the animal.

In the embodiment shown in FIGURES 4 and 5, the barrel 10 may be mounted above and opposite and disposed in parallel relationship to the charge chamber housing 6 and secured thereto by means of the mounting member 8. The gas expansion chamber housing 7, whose internal diameter is substantially greater than the external diameter of the barrel 10 may be formed around the rear portion 10a of the bar-rel 10 and the baffles, positioning means or spacing members 12 may position and secure the housing 7 on and to the rear portion 10a of the barrel 10 with such members 12 serving to silence the explosion in the charge chamber 6a.

The rear portion 10a of the barrel 10 and rear portion 70 of the housing 7 may be open ended and the rear portion 70 may have removably secured thereto an end closure member or breech cap 24 upon which the gases created by the detonation of the charge in the charge chamber 6a travelling through the gas expansion chamber 7a impinge and are directed in a reverse direction into the rear portion 10a of the barrel 10 and along such barrel 10 to expel the projectile from the muzzle end 10b of the barrel 10 and towards the animal.

In order to vary the velocity of the projectile as aforesaid, the control means cylinder 15 is mounted co-axially in front of and in association with the charge chamber housing 6. The cylinder 15 in the form of an additional gas expansion chamber is in communication with the passage 9 leading from the forward end of the charge chamber 6a and consequently it is also in communication with the gas expansion chamber.

In using this form, a charge is placed in the housing 6 and a projectile hypodermic syringe is inserted into the rear portion 10a of the barrel 10 and the closure member or breech cap 24 is secured to the rear portion 7c of the housing 7. The charge is then detonated by means hereinbefore described and the gases thus produced are led from the charge chamber 6a by the passage 9 to the forward portion 7b of the gas expansion chamber housing 7, and discharged into the gas expansion chamber 7a. The gases are then led through the gas expansion chamber 7a and impinge on the end closure member or breech cap 24 by which the gases are directed along the barrel 10 to expel the projectile as aforesaid.

In the arrangement shown in FIGURE 6, which is more suitable in the rifle form, there is provided a one piece block breech and chamber 100 into which a barrel sleeve 102 can be fitted by means such as screw 103. A barrel 102a preferably is fitted into sleeve 102 in an interchangeable relationship relative to the block 100. The block 100 comprises a charge receiving chamber 104 positioned immediately behind the barrel sleeve 102 and barrel 102a and a gas expansion chamber 105 positioned forwardly of the charge receiving chamber 104 and beneath the barrel 102a and barrel sleeve 102. A passage 106 is provided passing through the block 100 from the large receiving chamber 104 to the gas expansion chamber 105 and likewise a separate passage 107 is provided in the block 100 between the gas expansion chamber 105 and the barrel 102a.

The projectile (not shown) to be projected from the weapon can be positioned within the barrel 102a and the passage 107 from the expansion chamber 105 leads to a position immediately behind the normal position in which the projectile is placed within the barrel 102.

Portions only of the gas feed passages 106 and 107 are provided within the block 1, the further portions 106a, 107a of the gas passages 106, 107 being formed preferably in a gas port plug 108 which is attached by screw threading as at 109 within the block when the barrel 102a removed, is held in position within the block 100 by an additional screw 110 inserted through the block 100 and plug 108. The gas port plug 108 when in position completes the passage 107 from the gas expansion chamber 105 to the barrel 102a and also completes the gas feed passage 106 connecting the charge receiving chamber 104 and the gas expansion chamber 105.

The gas expansion chamber 105 formed within the block 100 consists of a sleeve 111 mounted concentrically within a gas expansion chamber housing 112 and is of substantially less diameter then the internal diameter of the gas expansion chamber housing 112 for enabling gases to pass between the inner surface of the gas expansion chamber housing 112 and the outer surface of this sleeve 111. The sleeve 111 is positioned co-axially within the gas expansion chamber housing 112 by means of baflles, positioning means or spacing members 113 through which the sleeve 111 passes. Gases passing through the chamber 105 may impinge on these bafiies 113 and thereby be disturbed for producing the desired mufiiing effect of the noise created by the detonation of the charge (not shown) in the charge receiving chamber 104.

Preferably the sleeve 111 and baffle members 113 and a portion 176 of the gas passage 107 leading to the interior of the sleeve 111 from the gas passage 107 in the block 100 leading from the gas plug 108 and charge receiving chamber 104 are formed integral and as a separate plug 114, which is inserted such as by screw threading 115 within the rear of the gas expansion chamber 105 provided within the block 100. Preferably the end of the plug 114 is provided with an O-ring seal 116 or the like to provide a seal between the interior of the gas expansion chamber 105 within the block and the outer atmosphere.

The sleeve member 111 extends forwardly within the gas expansion chamber housing 112 and terminates at a distance from the forward face 117 of the gas expansion chamber housing 112 which forward face 117 is blank, apart from a plurality of bores 118 passing therethrough and leading to a further chamber 119 provided within the block 100. A suitable number of bores 118 is six, provided in a circle around the periphery of the forward face 117 of the gas expansion chamber housing 112.

Gas control means are positioned within said further chamber 119 forwardly of the forward face 117 of the gas expansion chamber 105. This control means is a control cylinder 120 closed at its forward end, preferably by a removable plug member 121 and provided at its forward end with a control valve. This control valve is preferably formed as a hollow cylinder 122 having one end 123 formed with a thickened wall portion provided with a bore 124 therethrough, the end face 125 of this thickened portion being annular and encircling the mouth of the bore 124. The peripheral surface of this end face 125 is chambered as at 126. The outer surface of this control valve cylinder 122 is provided with a screw thread 127 and said further chamber 119'in the block 100 provided to contain this control valve is likewise screw threaded at 127, whereby upon insertion of this control valve within the chamber 119, the screw threads 127 co-operate to bring this end face 125 in contact with,

the outer surface of the forward face 117 of the gas expansion chamber 105 provided with the bores 118 therein, as mentioned above. The other end of the control valve with over the open end of the control cylinder 120 by means such as screw threading 128. When the end face 125 of the control valve is in contact with the outer surface of the forward face 117 of the gas expansion chamber 105 the mouth of the bore 124 of the control valve is closed by this forward face 117 and the location of the bores 118 in the forward face 117 of the expansion chamber 105 is such that they coincide with the chamfered portions 126 of the end face 125. A control sleeve 129 is attached to the outer surface of the control valve and pinned by means such as a screw, and to sleeve 129 is preferably provided with a circumferential scale thereon, whereby when the end face 125, of the control valve and forward face 117 of the gas expansion chamber .105 are in contact the zero of the scale on the control sleeve 129 coincides with an indicia on the block or other convenient position. The control sleeve 129 is preferably knurled (not shown) in part thereof to facilitate the rotating of the control sleeve 129 and the control valve attached thereto. A groove and an O-ring seal 130 are preferably provided at the end of the control valve near the end face 125 to provide a suitable seal between the inner surface of the chamber 110 in the block 100 and the outer surface of the control valve.

The interchangeable barrel 102:: is preferably formed with a pad 131 on its outer surface in the form of a segment of a circle (see FIGURE 7) which pad 131 has an associated recess 132 cut away within the barrel sleeve 102 within which the barrel 102:: is to be fitted, with the barrel 102a being able to slide into and out of the barrel sleeve 102. The locking type breach of this weapon in which the barrel 1020 is fitted with the pad 131 to locate in the recess 132 cut away from the barrel sleeve 102 enables the pad 131 to rotate into this recess 132 from the top so that the pad 131 is also capable of being moved longitudinally along the barrel sleeve 102. This also enables access to the breech. An important feature of this barrel lock is that it allows a large area for the insertion of the syringe projectile without requiring an unnecessary length to the weapon. Furthermore, the feature of the barrel 102a being able to slide within the barrel sleeve 102 and to lock very positively in a closed position reduces the actual length of lock. Furthermore, the facility to remove the gas port plug 108 which conveys the gases from the charge receiving chamber 104 to the gas expansion chamber 105 and from the gas expansion chamber 105 to the syringe breech or barrel 102a so that the barrel 102a itself may be Withdrawn and changed for an alternative calibre is of a special advantage.

Loading a projectile is very simple and quick. The barrel 102a is rotated and the pad 131 which locks the barrel 102a close relative to the sleeve 102 is brought up into the longitudinal recess 132 where it can move forward. In moving the barrel 102a forward the breech is exposed and the recess 132 becomes enlarged and the syringe projectile may be placed therein, so that when the barrel 102a is moved back along the recess, the projectile is fed into the barrel 102a and the pad 131 when it meets the face in the block 100 at the end of this recess 132 may then be rotated to take the pad 131 down into the recess 132 to lock the barrel 102a closed. A spring 133 is placed to the rear of the barrel 102a to provide a compressive force against the barrel 102a to keep the barrel 102:; closed.

Upon detonation of a charge (not shown) within the charge receiving chamber 104 the gases produced upon detonation pass from the charge receiving chamber 104 forwardly thereof through the gas plug 108 and into the passages 107a, 107, leading to the sleeve member 111 of the gas expansion chamber 105. The gas then passes into the portion of the gas expansion chamber 105 encircling the sleeve 111 via the baffles or spacing members 113 to the gas passage 106 in the block 100 and 10611 in the gas plug 108 leading to the projectile breech or barrel 102a. Here the gases force the projectile from the barrel 102a. The baifies or spacing members 113 effect a muifiing of the sound of the detonation as described above and the length of the path through the sleeve portion 111 and surrounding portion of the gas expansion chamber 105 and the gas passages 107a, 107 107b, 106, 106a, facilitates the reduction of the initial force of detonation, such that the force of the explosion acting upon the rear of the projectile is substantially reduced, thus preventing the destruction or distortion of a projectile by its force thereon. In order to reduce this force even further it is possible to extend the capacity of the gas expansion chamber by use of the control means. As stated above, with the graduated scale on the control sleeve 12a at its zero position the end face 125 of the control valve 125 containing the bore 124 lies in contact with the outer surface of the forward face 117 of the gas expansion chamber 105 so that no access through the bore 124 is possible. Passage through the bores 118 provided in the peripheral portion of this forward face 117 to the chamber 119 containing the control valve is facilitated via the chamfered outer periphery 126 of the end face 125 of the control valve. However the dimensions of the outer surface of the rest of control valve in conjunction with the seal 130 mentioned previously are such as to prevent any further passage of the gas from this chamber 119. However, upon rotating the control sleeve 129 and consequently the control valve 122 fixed thereto and thus unscrewing the control valve 122 on the threads 12?", the end face 125 of the control valve is gradually moved away from the outer surface of the forward face 117 of the gas expansion chamber 105 so that the gas passing through the bores 118 in this forward face 117 of the gas expansion chamber 105 may pass into the bore 129 of the control valve 122 along the bore 124 and into the control cylinder 120. The rotation of the control sleeve 129 is such that one revolution completes the movement of the control valve 122 between its limits of zero to maximum flow of gas from the gas expansion chamber 105 through the bores 118 to within the control cylinder 120. Upon partial opening of the control valve 122, the gas can pass through to the interior of the control cylinder and the actual degree of closure of the bore 124 is related to the degree of closeness of the opposed faces 117, 125 of the control valve 122 and expansion chamber 105 one to the other, and the greater this space between the two faces 117, 125 the more freely the gas will pass between the chambers 105 and control cylinder 120 and consequently the lesser the actual pressure of the gas reaching a projectile in the barrel 102a. The passage of the gas into the interior of the control cylinder 120 thus enlarges the capacity of the gas expansion chambers.

The form of the invention shown in FIGURES 8 and 9 is more adaptable to the pistol form of weapon and comprises a main block or frame 41 having chambers therein for receiving the other component parts or portions of the other component parts constituting the weapon. From FIGURES 8 and 9 one can see the components assembled in the block but the lower action and firing mechanism are not shown, with these being hinged at a screw on the frame 41 indicated at 42 in front of the trigger (not shown). This frame or block 41 has formed integral there in a barrel sleeve 42, a gas expansion chamber 43 formed therebelow and a further chamber 44 in communication with the gas expansion chamber 43 and formed forwardly of the gas expansion chamber 43 but also below the barrel sleeve 42. A breech chamber is formed at the rear of the barrel sleeve 42 and a gas passage 45 is provided through the frame 41 passing between the breech chamber and the rear of the gas expansion chamber 43 therebelow. Interchangeable barrels 46 may be inserted within the barrel sleeve 42 and locked into position. The inner end of the barrel sleeve 42 is provided on its outer surface with a pad 47 in the form of a segment of a circle arranged to locate in a recess 48 in the barrel sleeve 42, with the pad 47 being able to rotate in the recess 48 from the top and also being able to move longitudinally up and down the sleeve 4-2 to enable access to the breech and to allow the barrel 46 to be slid out of the barrel sleeve 42. The barrel 46 may slide up and down inside the barrel sleeve 42 forming part of the main frame 41 Where it is counterbored as at 49 to a larger diameter to enable the pad 47 to pass into the area of the longitudinal recess 40 in the top of the main frame 41, where the syringe breech is provided. The plan view of the barrel and sleeve in FIG- URE 9 shows the sleeve 42 of the frame with the barrel 13 46 inserted and the breech access recess 48 for the projectile is visible.

A barrel gas plug 50 is inserted within a gas plug housing 51 and is screw threaded therein as at 52. The gas plug housing is screw threaded into the breech as at 53. The gas plug has a bore 54 therethrough leading to the rear end of the barrel 46 and also having a further gas passage 55, which when the plug 51 is in position, forms an extension of the gas passage 45 passing through the frame between the breech chamber and the rear of the gas expansion chamber 43. With the gas plug screw 51 in position, the gas plug 51 forms a stop for the rotation of the barrel 46 to lock the barrel closed. The advantages of this form of interchangeable barrel and the sliding of the barrel and the barrel lock are described above with reference to the previous embodiment. Furthermore, the loading of the projectile may be effected in a similar way in that the barrel 46 is rotated within the sleeve 42 and the pad 47 which locks the barrel closed is brought up into the longitudinal recess 48 where it can move forward. In moving the barrel 46 forward, the breech is exposed and the recess 48 on top of the barrel sleeve 42 becomes enlarged and the projectile may be placed therein so that when the barrel 46 is moved back along the recess 48 the projectile is fed into the barrel 46 and the pad 47 when it meets the face at the end of this recess 48 may then be rotated to take the pad 47 down into the recess 48 to lock the barrel 46 closed. A spring 56 is placed between the rear end of the barrel 46 and an upstanding flange portion 57 provided on the barrel gas plug 50 to give a compressive force against the barrel 46 to keep the barrel 46 locked and closed. A groove and O-ring seal 58 is provided in the forward end of the gas plug to provide a suitable seal between the outer surface of the gas plug 50 and the inner surface of the barrel 46.

As in the other form of the invention described immediately above, the gas expansion chamber 43 is formed in two parts with the inner part being formed by a sleeve member 60 having spacing means or baffles 61 encircling the outer surface of the sleeve 60 past which the expansion gases may flow. This sleeve 60 is preferably formed insertablle within the gas expansion chamber 43 and held at its upper end by the outer part of the barrel gas plug housing 52engaging over a flange 62 at the upper end. The sleeve 60 when inserted within the gas expansion chamber 43 has a bore 63 in its upper outer surface, with this bore 63 forming an extension of the gas passage 45 provided in the frame 411. The bore in the sleeve 60 at its rearward end is in communication with the charge receiving chamber 44 positioned forwardly of the gas expansion chamber 43 and has inserted therein gas control means in the form of a gas control expansion chamber housing 64 closed at one end preferably by a screw threaded plug 65 which is removable if desired. The housing 64 is of smaller diameter rearwardly toward the gas expansion chamber 43. A gas control is formed at the junction between the gas expansion chamber 43 and the chamber 44 for the control means in that bores 66 are provided at the rearward end of the smaller diameter portion of the gas control expansion chamber housing 64. The bores 66 are provided in a bevelled end wall 67 of the gas control expansion chamber housing, and this end 67 is otherwise closed. The chamber 44 provided within the block or frame 41 for accommodating this gas control expansion chamber housing 64 is of such dimensions as to accommodate the smaller diameter portion of this housing 64 substantially Where it converges into the thicker portion thereof. A groove and O-ring seal 69 is also provided at a position between the screw thread 68 and the end wall 67 of the chamber housing 64 to provide a suitable seal between the inner surface of the chamber 44 and the outer surface of the smaller dimensioned portion of the gas control expansion chamber housing 64. A scalle (not shown) encircling the outer circumference of the housing 64 may be provided to co-operate with indicia marked on the frame 64 or where convenient. Furthermore, a knurled portion (not shown) may be provided on the outer surface of the gas control expansion chamber housing 64 to facilitate rotation of the housing 64 by hand. Upon rotating this housing 64 the screw threads 68 cooperate to rotate the housing 64 so that when the end closed wall 67 of the gas control expansion chamber housing 64 lie flush with a correspondingly shaped and dimensioned portion of this end of the chamber 44 whereby the bores 66 are completely closed and the zero mark of the scale (not shown) coincides with the appropriate indicia (not shown) mentioned above. By gradually rotating the housing 64 so that the screw threads 68 cooperate to unscrew the housing 64 forwardly from the chamber 44, a space gradually forms and increases between the outer face ot the bores 66 and the end wall of the chamber 44 such that gas within the gas expansion chamber 43 may pass into the adjacent chamber provided within the gas control expansion chamber housing 64 and the gas may likewise pass from within housing 64 to chamber 43, through boxes 45, 55 and 54 and to the rear of the projectile. The distance between the end face of the bores 66 and the face of the chamber 44 with which they co-operate in the zero position determines the speed at which the gas may pass from the charge receiving chamber to the rear of the projectile within the barrel.

The form of the invention shown in FIGURE 10, which is suitable to a revolver type pistol in which a revolver action having six cartridges rather than one may be fired in quick succession without pro-loading cartridges. A frame 70 is preferably formed with the handle and charge receiving chamber (shown in fragment) provided therein with the other components being connectible to this frame 70. Mounted on to the top strap of the frame 70 which has been provided with a fiat surface such as by milling, is a syringe breech 71 and gas expansion chamber 72 which are preferably formed as in integral construction. The gas expansion chamber 72 is formed below the syringe breech 71 and the rear of the gas expansion chamber 72 has a bore 73 therein which is p sitioned in line with the forward opening from a charge receiving chamber 74 and a gas expansion chamber housing 75 is held to the front of the frame 71 at the bottom by a lock pin 76 and cylinder pin 77. Furthermore, a hollow pin 78 passes through the bore 73 in the rear end of the gas expansion chamber '72 and has a head engaging against inner front surface of the charge receiving chamber 74 passing through the frame 70 and into the rear of the gas expansion chamber housing 75 held against the front of the frame 70. A hollow assembly nut 79 is screw threaded onto the inner end of the hollow pin 78, which is likewise screw-threaded as at 80 to hold the rear of the gas expansion chamber housing 75 to the frame 70.

The forward end of the gas expansion chamber is closed preferably by a screw threaded cap 81. A passage 82 from the rearward end of the gas expansion chamber above the hollow pin 78 connecting the chamber housing 75 to the frame 76 is provided passing through the syringe breech and gas expansion chamber construction and emerging into the syringe breech 71 thereabove. Thus, a passage is provided for gases passing directly from the charge receiving chamber 74 through the hollow pin 78 forwardly into the gas expansion chamber 72 and then rearwardly through the gas passage 82 into th rear of the syringe breech 71. Interchangeable barrels 83 can be fitted into a barrel sleeve 84 of the syringe breech 71 which has a longitudinal slot 85 cut away in its upper surface and a pad 86 attached on the outer surface of the barrel sleeve 84 has a section of a segment of a circle and is insertable within the breech 71 as previously described. Furthermore, a spring 87 is also provided between the end of the barrel 83- and the gas plug 88 to be later described, and which spring 87 is inserted within the breech 71 to provide the compression on the barrel 83 as above described.

The gas plug to be inserted in the rear of the syringe breech 71 has a longitudinal bore 89 therethrough together with a lateral bore 90 substantially perpendicular to the longitudinal bore 99 and converging therewith. This gas plug 88 is provided with a casing 91 which is pressed and welded over the outer surface of the gas plug 88 and has bores therethrough corresponding to the lateral bore 98 and is likewise open at each end. The casing 91 is provided with a screw thread 92 which cooperates with a screw thread within the inner rear end surface of the syringe breech l and thus the gas plug 88 can be inserted within the syringe breech 71 by screwing the casing thereof into the rear open end of the syringe breech '71. A stop pin 93 screw threaded along its shank as at 94 acts as a control valve at the junction between the longitudinal and lateral bores 89 and 9% respectively Within the gas plug Upon insertion within the rear end of the longitudinal bore 89, the inner end of the stop pin 92. terminates approximately adjacent this junction. Upon rotating the stop pin 93, the inner end of this pin 93 is moved from one limit at which the inner end of the stop pin 93 leaves free the area in which the longitudinal and lateral bores and )8 meet, to the other limit of movemerit of the stop pin 83, in which said area is completely closed on by the stop pin 93, so that connection between the lateral and longitudinal bores 89 and 90 is completely out off. Positioning of the pin 93 between these two limits thus varies the amount of connection between the lateral and longitudinal bores 89 and 90 within the plug 88 and thus controls the volume of gas entering from one bore to the other. With the gas plug 88 and its casing in position, the bores in the casing and gas plug 88 in coincidence, the lateral bore 10 of the gas plug 88 and easing acts as a continuation of the gas passage 82 extending from the rear of the 'as expansion chamber 72 through the integral breech and gas expansion chamber construction to the syringe breech 71. Consequently, gas formed u on detonation of a charge within the charge receiving chamber passes from the charge receiving chamber through the hollow pin 78 to the gas expansion chamber 72 and then rearwardly through the gas passage 82 to the lateral bore 89 in the gas plug 88 and gas plug casing 92. Here, the stop pin 93 has been rotated to control the volume of gas passing from this lateral bore 89 into the longitudinal bore 94 and thus to the rear of the projectile positioned forwardly of the plug 88 within the syringe breech 71. When the connection between the lateral and longitudinal bores and 98 within the gas plug 88 is reduced, at small volume of gas is permitted to enter the projectile breech '71 and thus a slow or low velocity is given to the projectile and similarly when the valve is opened completely, it allows a greater volume of gas to enter the projectile barrel thus creating a greater velc-city for the projectile. Graduations on the stop pin 93 or the surr cud of the gas plug housing 92 permits the degrees of passage opening to be read so that the velocity may be preset as desired. It is desirable that one revolution of the stop pin 83 covers the range between the two limits of the longitudinal movement of the stop pin 93. Although not shown in the drawing the battles and gas sleeve of the previously mentioned embodiments may also be included within the weapon presently described. Thus this arrangement differs from the previous arrangements in that the gas expansion chamber volume is fixed and no extension of this chamber is provided as in the other arrangements. However, the control is provided by the stop pin 93 controlling the volume of gas passing from the gas passage 8? into passage 90 and thus into the projectile breech.

ln yet another arrangement of the present invention, the revolver action may be adapted to the pistol weapon of FIGURES 8 and 9 in that the lower firing mechanism would be a revolver action and the cartridge chamber of the single shot weapon would be milled away in a similar manner to the frame of the pistol type weapon of FIG- lb URE 10 so that the frame would fit over the top strap of the revolver to locate on the forward section of the frame and lock in place with a central stud which also pro vides the gas passage from the charge receiving chamber to the smaller expansion chamber and gas control of the pistol to which this revolver action is adapted.

In a further arrangement of the present invention (not shown in the drawings), the block is formed with a gas expansion chamber therein as shown in the drawing and the barrel sleeve attachable to the block and in which barrel sleeve the barrel may be positioned so that it is readily interchangeable with other barrels of different calibres. The rear of the barrel is closed by a pressure cap, breech cap and breechlock, and the breechlock is pivotable. Syringes are loaded through this breech cap which is then closed and locked. Bores such as eight in number around the barrel surface provide communications between the interior of the barrel and the interior of the rear part of the barrel sleeve which is of smaller wall thickness than the front part of the barrel sleeve to define an encircling chamber around the outer surface of the barrel. At the front portion of this surrounding sleeve is a further bore coinciding with a bore in the block. This bore leads into the gas expansion chamber having a bore at the rear thereof which is arranged to coincide with the outlet from the charge receiving chamber. The gas expansion chamber and charge receiving chamber are held in position relative to one another by means of the hollow pin maintained in position by an assembly nut as described in FIGURE 8. A sleeve member having baffies attached to the outer surface as in the previous arrangements is also provided in the gas expansion chamber whereby the sleeve coincides with the bore of the hollow pin so that communication for gas formed upon detonation of a charge within the charge receiving chamber is provided between the charge receiving chamber to the bore in the block leading to the rear of the barrel. The front of the gas expansion chamber may be closed by a cap which can be screw threaded into the end of the chamber. The valve means is provided in the block in the form of a rotating plug interposed between the bore in the block and the bore leading into the barrel sleeve at right angles thereto. The rotating plug is provided with bores of different diameters, preferably three bores which, when in alignment, communicate, the bore in the block with the bore in the barrel sleeve. A screw thread is provided on the outer surface of the plug and on the inner surface of the cavity provided in the block to accommodate the plug with detents being so situated on the plug that when one detent is located in a corresponding position on the block, one of the bores in the plug provides communication between the bore in the block with the bore in the barrel sleeve. When the next detent is in alignment with the corresponding member on the block, a bore in the plug of ditferent diameter effects communication between the bore in the block with the bore in the barrel sleeve and likewise with the third detent. When the bore with the smallest diameter provides communication between the bore in the block and the bore in the barrel sleeve, then flow of gas from the gas expansion chamber through the bore in the block and through the plug is restricted whereby the force on the projectile in the barrel is small. When the plug is so turned that a bore of larger diameter effects communication between the bore in the block and the bore in the barrel sleeve then a greater velocity of flow of the gas occurs between the gas expansion chamber and the barrel thus producing a greater force on the projectile and a greater velocity for the projectile. The outer face of the plug is preferably marked to indicate the three positions but of course, more than three positions may be provided. It is essential that in view of the danger of providing no communication between the barrel block and breech it is necessary that the plug be detented to ensure that one of the bores provides a path between the bore in the block and the bore in the barrel sleeve since otherwise escape of the gas from the gas expansion chamber will be impossible and likewise dangerous.

In yet another arrangement (not shown in the drawings), the rotating plug may be replaced by a hollow sleeve having bores of different diameters positioned at strategic points along the sleeve and the sleeve is interposed between the' bore connecting the barrel with the bore communicating with the gas expansion chamber, whereby rotation of the sleeve facilitates passage of gas from the gas expansion chamber through the bore in communication with the bore in the block and up through the block into the barrel. It will also be necessary to provide detent means in this case in order to ensure that one of the holes of different diameters in the sleeve facilitates communication between the gas expansion chamber and the barrel as otherwise the detonation gases will not be able to escape from the gas expansion chamber and this would be rather dangerous.

Not only is the projecting device or Weapon of the present invention in its several forms capable of a great range of variation of the gas pressures produced by the explosion or ignition of an explosive compound to provide a controlled force of propulsion but it also processes the gases produced to give a very manageable pressure of gas to do a definite function. It similarly reduces the sound of ignition or explosion to a very insignificant pop or hiss compared with a very loud bang experienced with most devices using an explosion as a propelling force but there are always associated with the afterfunction of the explosion gases. A rifle or pistol has a silencer on the muzzle, but the present invention is coupled over the actual explosion before the gases are put to work. It is incorporated in the actual design of the early processing areas before the gases are used in any way.

Regardless of the actual relationship of the expansion chambers or gas passages and valves in these various designs, the basic function in each case is still the same and that of controlling the explosion to provide a manageable pressure of gas to do a certain job of work.

Without this it is not possible to use projectiles made of very light materials such as for example plastic which would collapse if subjected to the destructive forces of the explosion no matter how small a quantity of explosive used if it is such that the explosion takes place immediately behind the projectile as in conventional weapons.

Certain very high explosives which are known to have many times the destructive force of conventional explosives normally used in shells, etc. could not be used in conventional weapons because the actual shock of the propelling charge is sufiicient to cause the charge contained in the projectile to be detonated by the propelling explosion. However, as the controlled gases of the moderated explosion in the present weapon provides a propelling force which is capable of comparatively long ranges for light explosive projectiles without this danger of shock detonation of such high explosives, a number of them may be used in such a weapon with complete safety.

The many advantages then available by these factors of controlled explosion propelling forces enables small projectiles into which special shaped charges have been fitted to be used over considerable distances not only with very little noise of discharge and no flash or smoke which would give away the position of the weapon but the destructive force of the explosive used in the projectile due to its greater explosive force compared with conventional explosives is capable of much damage at the point of impact.

Other applications now possible with this type of weapon are the field of nerve and tear-gas or even smoke type missiles which may be provided as molded plastic projectiles filled with liquified gas and so designed that a very small detonator, fitted to the front of the projectile,

upon impact, explodes to shatter the plastic body and disperse the liquid as a gas. The fragments of shattered plastic have very little danger for persons in the area of impact. Such projectiles could not be used in conventional weapons as they would not withstand the shock of the propelling explosion.

This invention is not to be confined to any strict conformity to the showings in the drawings but changes or modifications may be made therein so long as such changes or modifications mark no material departure from the spirit and scope of the appended claims.

I claim:

1. A projecting assembly for projecting a projectile, comprising supporting means, a housing constituting a gas expansion chamber defining means and breech means carried by said supporting means, a charge receiving chamber, said gas expansion chamber being in communication with a charge receiving chamber, barrel means removably mounted within the breech means and ar' ranged to receive a projectile, first passage means providing communication between the gas expansion chamber and said breech means, gas plug means removably engaged within said breech means, second passage means within said gas plug means providing communication between said first passage means and said barrel means to the rear of the projectile, valve means in said second passage means, said valve means being actuable to control the degree of communication and the volume of gas passing between said charge receiving chamber means and said barrel means to the rear of the projectile via said gas expansion chamber means upon detonation of the charge in the charge receiving chamber whereby the velocity and/or range of the projectile leaving the barrel may be varied.

2. A projecting assembly for projecting a projectile comprising supporting means, a housing constituting a gas expansion chamber defining means and breechmeans carried by said supporting means, a charge receiving chamber, said gas expansion chamber being in communication with the charge receiving chamber, barrel means removably mounted within the breech means and ar ranged to receive a projectile, first passage means providing communication between said gas expansion chamber and said breech means, a gas plug means engageable within said breech means to the rear of the said barrel means, said gas plug means having a longitudinal bore therein communicating with the rear of said barrel means, said gas plug means having a lateral bore therein communicating with said first passage means, said bores con verging to form a junction with one another within said gas plug means, threaded pin means engageable within the rear end of said longitudinal bore, the inner end of said pin means being actuable as a valve means within said junction to completely close off said junction and being actuable to completely open said junction and par tially open said junction whereby control of the volume of gas passing between said charge receiving chamber means and said barrel means to the rear of the projectile via said gas expansion chamber upon detonation of the charge in the charge receiving chamber may be effected whereby the velocity and/or range of the projectile leaving the barrel may be varied to a predetermined degree.

3. The projecting assembly for projecting a projectile, as claimed in claim 2 which includes a calibrated indicating means provided on said projecting assembly in the comprising supporting means, a housing constituting a gas expansion chamber defining means and a breech means carried by said supporting means, a charge receiving chamber, said gas expansion chamber being in communication with the charge receiving chamber, said breech means having an internal thread at the rear end thereof, first passage means providing communication between the gas expansion chamber and said breech means, a gas plug casing having an outer thread, said gas plug casing being threaded into engagement with the internal thread at the rear of said breech means, a gas plug, screw means retaining said gas plug within said gas plug casing, said gas plug having a longitudinal bore therein communicating with the rear of said barrel means, said gas plug means having a lateral bore therein, said bores converging to form a junction with one another within said gas plug means, said gas plug casing having aperture means in alignment with said lateral bore to provide communication between said lateral bore and said first passage means, and threaded pin means engageable within the rear end of said longitudinal bore, the inner end of said pin means being actuable as a valve means within said junction to completely close off said junction and completely open said junction and being actuable within said junction to partially open said junction whereby control of the volume of gas passing between the charge receiving chamber and said barrel means to the rear of the projectile via said gas expansion chamber upon detonation of the charge in the charge receiving chamber may be effected whereby the velocity and/or range of the projectile leaving the barrel may be varied to a predetermined degree.

5. The projecting assembly for projecting a projectile, as claimed in claim 4 which includes a longitudinal slot provided part way along the length of said breech means, interchangeable barrel means insertable within said breech means, a segmental pad provided adjacent the inner end of said barrel means, a recess being provided within said breech means, said pad being engageable within said recess, an annular recess provided on the inner end of said gas plug means, a helical spring engaging within said annular recess in said gas plug means whereby said segmental pad is retained within said recess in the breech means by action of said helical spring acting on the inner end of said interchangeable barrel means with rotation of said barrel means and said segmental pad therewith allowing release of said pad from the recess within said breech means and forward movement of said interchangeable barrel means with said pad guided along said longitudinal slot in said barrel means allowing insertion of projectile into the rear of said barrel means in front of said gas plug means, with rearward movement of said barrel means and rotation of said pad into said recess in said barrel means causing locking of the barrel means into position ready for use.

6. A projecting assembly for projecting a projectile comprising a pistol frame unit having a flat surfaced top strap and a charge receiving chamber means incorporated therein, a separate breech unit having a breech means therein and formed with a gas expansion chamber means integral therewith, said breech unit being releasably mounted on said top strap with gas expansion chamber means in alignment with said charge receiving chamber means, a hollow pin means engageable between the charge receiving chamber means and the gas expansion chamber means to provide communication therebetween, a cylinder pin means and a lock pin means connecting and releasably locking said frame with said separate breech unit, barrel means removably mounted within the breech means and arranged to receive said projectile, means providing communication between said gas expansion chamber means and said barrel means to the rear of the projectile, valve means provided in said communication means, said valve means being actuable to control the degree of communication and consequently the volume of gas passing between said charge receiving chamber means and said barrel means to the rear of the projectile via said gas expansion chamber means and hollow pin means upon detonation of the charge in the charge receiving chamber whereby the velocity and/ or range of the projectile leaving the barrel may be varied.

7. The projecting assembly for projecting a projectile as claimed in claim 6 in which said pistol frame unit includes a handle integral therewith.

8. A projecting assembly for projecting a projectile, comprising a pistol frame unit having a flat surfaced top strap and a charge receiving chamber means incorporated therein, a separate breech unit having a breech means therein and formed with a gas expansion chamber means integral therewith, said breech unit being releasably mounted on said top strap with the gas expansion chamber means in alignment with the charge receiving chamber means, a hollow pin means engageable between the charge receiving chamber means and the gas expansion chamber means providing communication therebetween, a cylinder pin means and a lock means connecting and releasably locking said frame with said separate breech unit, barrel means removably mounted within the breech means and arranged to receive a projectile, first passage means within said breech unit extending between the gas expansion chamber means and said breech means, second passage means within said gas plug means providing communication between said first passage means and said barrel means to the rear of the projectile, valve means in said second passage means, said valve means being actuable to control the degree of communication and consequently the volume of gas passing between said charge receiving chamber means and said valve means to the rear of the projectile via said gas expansion chamber means and hollow pin means upon detonation of the charge ,in the charge receiving chamber whereby the velocity and/or range of the projectile leaving the barrel may be varied.

9. A projecting assembly for projecting a projectile, comprising a pistol frame unit having a fiat surfaced top strap and a charge receiving chamber means incorporated therein, a separate breech unit having a breech means therein and formed with a gas expansion chamber means integral therewith, said breech unit being releasably mounted on said top strap with the gas expansion chamber means in alignment with said charge receiving chamber means, a hollow pin means engageable between the charge receiving chamber means and the gas expansion chamber means providing communication therebetween, a cylinder pin means and a lock pin means connecting and releasably locking said frame with said separate breech unit, barrel means removably mounted within the breech means and arranged to receive said projectile, first passage means within said breech unit extending between the gas expansion chamber means and said breech means, a gas plug means engageable within said breech means to the rear of said barrel means, said gas plug means having a longitudinal bore therein communicating with the rear of said barrel means, said gas plug means having a lateral bore therein communicating with said first passage means, said bores converging to form a junction with one another within said gas plug means, threaded pin means engageable within the rear end of said longitudinal bore, the inner end of said pin means being actuable as a valve means within said junction to completely close said junction, completely open said junction and to open said junction whereby control of the volume of gas passing between said charge receiving chamber and said barrel means to the rear of the projectile via said gas expansion chamber means and hollow pin means may be effected upon detonation of the charge in the charge receiving chamber whereby the velocity and/or range of the projectile leaving the barrel may be varied to a predetermined degree.

10. A projecting assembly for projecting a projectile,

comprising a pistol frame unit having a fiat surfaced top strap and a charge receiving chamber means incorporated therein, a separate breech unit having a breech means therein and formed with a gas expansion chamber means integral therewith, said breech unit being releasably mounted on said top strap with the gas expansion chamber means in alignment with said charge receiving chamber means, a hollow pin means engageable between the charge re ceiving chamber means and the gas expansion chamber means providing communication therebetween, a cylinder pin means and a lock pin means connecting and releasably locking said frame with said separate breech unit, barrel means removably mounted within the breech means and arranged to receive a projectile, said breech means having an internal thread at the rear end thereof, first passage means within said breech unit extending between the gas expansion chamber means and said breech means, said gas plug casing having an outer thread, said gas plug casing being threaded in engagement with the internal thread at the rear end of said breech means, a gas plug, screw means retaining said gas plug within said gas plug casing, said gas plug having a longitudinal bore therein communicating with the rear end of said barrel means, said gas plug having a lateral bore therein, said bores converging to form a junction withone another within said gas plug, aperture means within said gas plug casing in alignment with said lateral bore to provide communication between said lateral bore and said first passage means, threaded pin means engageable within the rear end of said longitudinal bore, the inner end of said pin means being actuable as a valve means within said junction to completely close said junction and actuable to completely open said junction and partially open said junction whereby control of the volume of the gas passing between said charge receiving chamber means and said valve means to the rear of the projectile via said gas expansion chamber means and hollow pin means may be effected upon detonation of the charge in the charge receiving chamber whereby the velocity and/or range of the projectile leaving the barrel may be varied to a predetermined degree.

References Cited UNITED STATES PATENTS 3,118,242 1/1964 Snyder 42-1 2,966,904 1/1961 Crockford et a1 421 3,168,744 2/1965 Kvavle 227-10 3,204,400 9/ 1965 Kvavle 227-9 BENJAMIN A. BORCHELT, Primary Examiner. T. H. WEBB, Assistant Examiner.

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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3745682 *Sep 28, 1971Jul 17, 1973Pneu Dart IncGun for propelling a drug or medicine projectile
US4467544 *Sep 30, 1982Aug 28, 1984Gerwig Phillip LHypodermic dart gun
US4953316 *Sep 25, 1989Sep 4, 1990Litton Sr Ernest CChoke storage device for shotguns
US5078118 *Dec 20, 1989Jan 7, 1992Brass Eagle Inc.Breech construction for air gun
US5224465 *Mar 6, 1992Jul 6, 1993Crosman CorporationAir gun with baffle for limiting maximum velocity
US6258063Jan 16, 1998Jul 10, 2001Roche Diagnostics GmbhHypodermic injection system
US6374720Nov 22, 1999Apr 23, 2002Salvatore TeddeFirearm with an expansion chamber with variable volume
US7806867Sep 8, 2003Oct 5, 2010Valeritas, Inc.Injection device
US8783155Feb 8, 2010Jul 22, 2014Metal Storm LimitedStacked projectile launcher and associate methods
WO1998028587A1 *Dec 22, 1997Jul 2, 1998Dynamit Nobel GmbhNonlethal weapons
WO1998031409A2 *Jan 16, 1998Jul 23, 1998Manfred BeuttenmuellerHypodermic injection system
WO1998053266A1 *May 22, 1998Nov 26, 1998Salvatore TeddeFirearm with an expansion chamber with variable volume
Classifications
U.S. Classification42/106, 124/73
International ClassificationF41C7/00, F41A21/28, F41A1/00, F41A1/06, F41A21/00, A61D7/00
Cooperative ClassificationF41A1/06, F41A21/28, F41C7/00, A61D7/00
European ClassificationF41A1/06, F41A21/28, F41C7/00, A61D7/00