PROJECTILE CARRIER FOR A VALVELESS GAS GUN

Abstract

Projectile carrier for a gas gun with a barrel defining a barrel bore arranged to guide a projectile, the projectile carrier including a projectile carrier bore for holding a projectile aligned with a barrel bore of the gas gun and to be sealingly in communication with a pressure chamber when the projectile carrier is in a service position, the projectile carrier being adapted to receive a projectile when in a loading position. The projectile carrier is distinct from the barrel and includes at least one projectile retaining element held in place by at least one locking element arranged to move on the projectile carrier between a locking position, in which the at least one projectile retaining element is engaged with a retention surface included by the projectile, and an unlocked position, in which the projectile is free to move under the effect of pressure in the pressure chamber.

Claims

1. Projectile carrier for a gas gun provided with a barrel defining a barrel bore arranged to guide a projectile, said projectile carrier comprising a projectile carrier bore adapted to hold a projectile aligned with said barrel bore of said gas gun and to be sealingly in communication with a pressure chamber when the projectile carrier is in a service position, the projectile carrier being adapted to receive a projectile when in a loading position, wherein said projectile carrier is distinct from said barrel and comprises at least one projectile retaining element held in place by at least one locking element arranged to move on the projectile carrier between a locking position, in which the at least one projectile retaining element is engaged with a retention surface comprised by the projectile, and an unlocked position, in which the projectile is free to move under the effect of pressure in the pressure chamber.

2. The projectile carrier according to claim 1, wherein the at least one projectile retaining element is at least one lever, pin or ball bearing.

3. The projectile carrier according to claim 1, wherein said locking element is a plunger arranged to cooperate with said at least one projectile retaining element hydraulically.

4. The projectile carrier according to claim 1, wherein the at least one locking element is a sliding sleeve arranged to slide on the projectile carrier, and which is arranged to act directly or indirectly on said at least one projectile retaining element.

5. The projectile carrier according to claim 4, wherein the projectile carrier further comprises an elastic element arranged to bias the sleeve in its locking position.

6. The projectile carrier according to claim 5, wherein the sleeve comprises a tubular extension arranged to maintain the at least one projectile retaining element in engagement with the projectile.

7. The projectile carrier according to claim 6, wherein the tubular extension comprises a cylindrical inner surface arranged to block the at least one projectile retaining element in engagement with the projectile, and an interior bevelled surface situated towards the open end of the tubular extension.

8. The projectile carrier according to claim 4, wherein said sliding sleeve is arranged to act indirectly on said at least one projectile retaining element via at least one lever or locking arm.

9. The projectile carrier according to claim 1, wherein the pressure chamber is integrated therewith.

10. The projectile carrier according to claim 9, further comprising a protective shroud adapted to limit access to the locking element.

11. The projectile carrier according to claim 1, adapted such that the projectile carrier bore can be brought into communication with the pressure chamber when the projectile carrier is in said service position, the pressure chamber being integrated with said gas gun.

12. Gas gun comprising: a frame; a barrel attached to the frame and defining a barrel bore arranged to guide a projectile; a housing provided in the frame adapted to receive the projectile carrier according to claim 9 such that the projectile carrier bore is aligned with the barrel bore; an actuator attached to the frame and adapted to move the locking element from its locked position to its unlocked position.

13. Gas gun comprising: a frame; a barrel attached to the frame and defining a barrel bore arranged to guide a projectile; a pressure chamber attached to the frame and adapted to contain a pressurised gas; a housing provided in the frame adapted to receive the projectile carrier according to claim 11 such that the projectile carrier bore is aligned with the barrel bore and sealingly in communication with the pressure chamber; an actuator attached to the frame and adapted to move the locking element from its locked position to its unlocked position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Further details of the invention will become apparent upon reading the detailed description below, in reference to the annexed figures in which:

[0031] FIG. 1 schematically represents a gas gun provided with a non-limiting embodiment of a projectile carrier according to the invention in cross section, in a position ready to launch a projectile; and

[0032] FIG. 2 schematically represents the gas gun of FIG. 1 in cross section, immediately after launching a projectile;

[0033] FIG. 3 schematically represents a further nonlimiting embodiment of a gas gun provided with a projectile carrier according to a second non-limiting embodiment of the invention in a view similar to that of FIG. 1;

[0034] FIG. 4 schematically represents, in three side views and one bottom view, a particular variant of a pin which can serve as projectile retaining element;

[0035] FIG. 5 illustrates schematically in cross-section a particular arrangement of projectile carrier in which the pins of FIG. 4 are maintained in position by levers which are themselves retained and released by the locking element;

[0036] FIG. 6 schematically represents a particular manner of guiding the pins of FIG. 4;

[0037] FIG. 7 illustrates two variations of arrangements for blocking the pin 23b in its engaged position;

[0038] FIG. 8 illustrates in schematic cross-section a manner in which the pins of FIG. 4 can be sealed to the projectile carrier;

[0039] FIG. 9 illustrates in schematic cross-section a particular variant in which the pins are retained and released hydraulically;

[0040] FIG. 10 illustrates in partial schematic cross-section a yet further variant of a projectile carrier in which the projectile retaining elements are a plurality of levers arranged as a collet;

[0041] FIG. 11 illustrates in partial cross-sectional view a particular arrangement for retaining and releasing the pins in an arrangement derived from that of FIG. 5.

EMBODIMENTS OF THE INVENTION

[0042] FIGS. 1 and 2 illustrate schematically a gas gun 1 provided with a projectile carrier 13 according to a first non-limiting embodiment of the invention.

[0043] Gas gun 1 comprises a frame 3 (represented schematically by appropriate symbols) to which a barrel 5 and a pressure chamber 7 are attached. Depending on the nature of the gas gun 1, the frame may comprise e.g. a chassis to which is attached a stock, pistol grip, a mount, or any other suitable known elements, depending on whether it is a rifle, pistol, artillery piece or other.

[0044] Barrel 5 is a tube with a cylindrical barrel bore 5a, which may be smooth bored or provided with rifling in order to impart a spin to a projectile about its major axis, as is generally known and hence need not be explained at length. The barrel 5 may be rigidly fixed to the frame 3 such that it can only be exchanged with a tool by technician, or so that it can be easily exchanged by the user.

[0045] Pressure chamber 7 is defined by a cavity which can be filled with gas such as air, nitrogen or similar from a pressure source 9 (such as a gas bottle, compressor or similar) via a valve 11. Pressure source 9 may be integrated with the gun (e.g. fixed to the frame permanently or removably), or may be a separate element attached via a hose.

[0046] In the illustrated embodiment, the pressure chamber 7 is coaxial with the barrel 5, however this does not have to be the case. It is, however, advantageous for it to be so, since this minimises resistance to the gas flow upon projectile release.

[0047] The pressure chamber 7 is brought into fluid communication with the barrel 5 by means of a projectile carrier 13, comprising a projectile carrier bore 13a arranged to receive and to support a projectile 15 aligned with the bore 5a of the barrel 5 when the projectile carrier 13 is in its service position as indicated in the figures. Projectile carrier 13 may have a circular, square or polygonal cross-section, considered perpendicular to the axis of the projectile carrier bore 13a. As is clear from the figures, the barrel 5 and the carrier 13 are distinct parts not integrated with each other, and hence barrel bore 5a and carrier bore 13a are likewise distinct features, since they are provided on the aforementioned two distinct, separate parts, which can be brought together so as to align the two bores 5a, 13a with each other.

[0048] Furthermore, in this service position, the projectile carrier 13 is held in a housing 3a (illustrated schematically) secured to or integral with the frame 3, with its rear face of (i.e. its face facing the pressure chamber) sealed to the front face of pressure chamber 7 (i.e. the face of the pressure chamber facing the barrel 5) by means of a pressure chamber seal 17, which may be an O-ring seal of any convenient polymer or elastomer material suitable to withstand the pressure in the pressure chamber 7, which is typically up to 300 bar gauge. Such materials (such as nylon, PTFE, rubber and similar) are well known in the art and need not be described at length.

[0049] Projectile 15 is provided with at least one projectile seal 19 arranged in a corresponding circumferential groove 20 of appropriate size, in order to seal the projectile to the projectile carrier bore 13a and prevent gas escape. Since the projectile seal 19 is subject to significant frictional forces during the launch of the projectile 15, the choice of material is limited to those capable of withstanding the friction and heat generated, for instance nylon, PTFE, or even soft metals such as lead arranged so as to provide an interference fit with the projectile carrier bore 13a. Since the base of the projectile 15 is exposed to the full pressure in the pressure chamber 7 while waiting to be launched due to there being no valve between the two, the projectile seal is hermetic.

[0050] The shape of the projectile 15 is generally cylindrical, cylindroconical, ogival or similar, and many examples of projectile shapes are well known in the art, and indeed the projectile may be inert or have an explosive load. Typically the cross-section of the projectile 15 is circular, but polygonal Whitworth-type and oval Lancaster-type shapes are also possible. Projectile 15 may also be provided with a sabot, and may even be a bolt, nail or similar intended to be driven by the gas gun 1 into a material for building purposes.

[0051] In order to retain the projectile 15 in the projectile carrier 13, at least one projectile retaining element 23 is provided, mounted to the projectile carrier (and hence not directly to the frame 3). In the illustrated embodiment, a pair of projectile retaining elements 23 are visible, but the number may vary, and experiments have shown that six is a particularly advantageous number. In this instance, each projectile retaining element 23 is an L-shaped lever mounted pivotally on the projectile carrier 13 and provided with an extremity 23a extending through a respective lateral opening 13b formed in the sidewall of the projectile carrier 13. The tip of each extremity 23a is curved or bevelled, and is adapted to engage with a retention surface 15a comprised by the projectile 15. In the illustrated embodiment, this retention surface is formed as a recess 15a of complementary form to the tips of the extremity 23a, which is provided in the outer wall of the projectile 15. As illustrated, the tips are rounded, and the recess 15a is formed as a circumferential groove with a similar profile to the tips. Alternatively, the tips may be bevelled into a symmetrical or asymmetrical V shape, the recess or recesses 15a having a complementary form. Furthermore, the extremities 23a may be curved so as to follow the circumference of the recess 15a. As a further alternative, the extremities 23a may engage with front portion of the projectile, whether this be the inclined surface of a so-called ogival form, or a flat front face if such is present.

[0052] Other forms of projectile retaining elements 23 are also possible, such as ball bearings, pins or similar.

[0053] In order to maintain the projectile retaining elements 23 in engagement with the projectile 15, at least one locking element 21 is provided.

[0054] In the illustrated embodiment, locking element 21 is a sleeve slidingly mounted on the outer wall of the projectile carrier 13 and provided with a cylindrical extension 21a shaped so as to block the retaining elements 23 in engagement with the projectile 15 when the sleeve is in its locking position as illustrated in FIG. 1, and thereby prevent the retaining elements 23 from disengaging from the projectile 15. The sleeve is maintained in this locking position by means of an elastic element 25, e.g. a coil spring, arranged so as to bias the locking element 21 towards the projectile retaining elements 23, i.e. in the direction of the pressure chamber 7, so as to retain it in the locking position.

[0055] As can be seen from FIG. 1, the projectile seal 19 is situated closer to the pressure chamber 7 than the recess 15a (or other retention surface as applicable), in order to prevent gas leaks through the openings 13b and obviate the need for good sealing at these points.

[0056] The projectile carrier 13 is sealed to the rear face of the barrel 5 by means of a barrel seal 27 similar to pressure chamber seal 17, although this feature can be omitted at the cost of slight loss of pressure between the projectile carrier 13 and the barrel 5 during discharge.

[0057] In order to launch the projectile 15, the projectile carrier 13 is placed in its service position as illustrated in FIG. 1, the pressure chamber 7 is then pressurised from the pressure source 9, and the locking element 21 is moved from its locking position into an unlocked position by means of an actuator 29 mounted to the frame 3. This actuator 29 has been illustrated as a simple trigger lever pivoted on the frame, but other arrangements are also possible, which may be purely mechanical, magnetic, electromechanical, pneumatic, hydraulic, or any combination thereof.

[0058] As the locking element 13 is moved to the point at which the projectile retaining elements 23 are no longer blocked in position, the cooperation between the shape of the recess 15a (or other retaining surface) and the projectile retaining elements 23 causes these latter to cam out of their position as the pressure force on the base of the projectile 15 forces it towards the barrel 5. Once the projectile is disengaged from the projectile retaining elements, it is free to accelerate along the barrel 5 under the effect of the gas pressure in the pressure chamber 7.

[0059] In the illustrated embodiment, the tubular extension 21a comprises an interior cylindrical surface 21b arranged to block the projectile retaining elements 23 in their engaged position, and an interior bevelled surface 21c situated towards the open end of the tubular extension 21a. This bevelled surface 21c is arranged such that, once the projectile 15 has departed, the elastic element 25 returns the locking element 21 to its original position by camming the projectile retaining elements 23 into their locking positions as illustrated in FIG. 1.

[0060] This particular arrangement, although advantageous, is not limiting, and many other possible arrangements of locking elements 21 are possible. In the case in which the extremities of the projectile retaining elements 23 are perpendicular to the bore axis, the locking element or elements 21 need to actively cam them out of engagement with the recess or recesses 21 by means of levers, linkages, cams, cam tracks or similar, by rotating, sliding, pivoting or otherwise displacing the locking element or elements 21.

[0061] In order to load the projectile carrier 13, it is arranged to be movable or removable. For instance, it may be hinged or slidingly mounted on the frame 3 so as to be able to be moved from its service position (as illustrated) into a loading position distinct from the service position. In this loading position, a projectile can be inserted into the projectile carrier bore 13a manually or via an autoloader mechanism, from either end thereof, an insertion following the direction of projectile traffic being preferred (but not obligatory) since it avoids all risk of damaging the seal 19 since it does not have to be pushed past the openings 13b. Alternatively, the projectile carrier may be completely removable. An appropriate positioning means such as a catch, locking system or similar may be provided to maintain the projectile carrier 13 securely in its service position.

[0062] Furthermore, multiple projectile carriers 13 may be attached together, e.g. by being linked together in a belt or chain, arranged in a revolver cylinder type manner, or attached side by side in a harmonica-type arrangement, the arrangement of projectile retaining elements 23 and locking elements 21 being adapted in consequence. Another possibility is storing multiple removable projectile carriers 13 in a magazine or hopper, with a suitable feeding mechanism to bring them sequentially into their service position.

[0063] As can be seen from the foregoing, the gas gun 1 of the invention is valveless (as in that it has no valve between the pressure chamber 7 and the projectile), so can generate high projectile 15 velocities, yet can nevertheless be loaded relatively rapidly by means of one or more projectile carriers 13.

[0064] Furthermore, since the pressure chamber 7 is fixed to the frame 3 of the gas gun 1 and is not formed integrally with the projectile carrier 13 in the manner of an air cartridge, there is no risk of a projectile being launched outside of the gas gun 1 in the case in which the locking element 21 is accidentally actuated.

[0065] FIG. 3 illustrates a further non-limiting embodiment of a gas gun 1 incorporating a projectile carrier 13 according to the invention, in which this latter takes the form of an air cartridge. In the interests of brevity, this construction will be described in terms of how it differs from that of FIGS. 1 and 2, and only those reference signs used below in the text are reproduced on FIG. 3, the other features remaining unchanged.

[0066] The fundamental difference between the embodiment of FIG. 3 and that of FIGS. 1 and 2 is that the pressure chamber 7 is integrated into the projectile carrier 13 such that this latter constitutes an air cartridge, the pressure chamber 7 being pressurised after insertion of the projectile 15, when the projectile carrier 13 is not in its service position.

[0067] In the illustrated embodiment, the pressure chamber 7 is formed in a separate element which is then attached to the portion of the projectile carrier 13 incorporating the projectile carrier bore 13a, e.g. by screw threads, a threaded locking collar 31 (as illustrated), a bayonet mount or any other convenient means. In order to load a projectile 15, the pressure chamber 7 can be unscrewed from the remainder of the projectile carrier 13 and the projectile 15 can be inserted in its direction of travel upon launch (i.e. from right to left in the orientation of the figures), or alternatively the pressure chamber 7 can remain attached and the projectile 15 loaded in the other direction with the increased risk of damage to the seal 19 that this entails, as noted above in the context of FIG. 1. In an alternate construction, part of the projectile carrier bore 13a may be provided in the element containing the pressure chamber 7, and a mechanical abutment (such as a shoulder) arranged as a projectile stop can be provided therein. In such a case, the projectile can be placed base first against this mechanical abutment, and the remainder of the projectile carrier 13 attached thereto, the dimensions being chosen such that the projectile retaining elements 23 engage directly with the groove 15a.

[0068] Alternatively, the pressure chamber 7 may be formed integrally (i.e. as a single piece) with the portion of the projectile carrier 13 incorporating the projectile carrier bore 13, which permits elimination of the pressure chamber seal 17 and the means to attach the pressure chamber 7 to the portion of the projectile carrier 13 containing the projectile carrier bore 13a. This arrangement comes with the proviso that the projectile seal 19 passes the lateral openings 13b upon loading from the front (i.e. in the direction opposite to projectile travel upon launch), with the attendant risk of damage to the seal 19, although this can be mitigated by careful manufacture.

[0069] Since an accidental actuation of the locking element 21 when the pressure chamber 7 is pressurised and the cartridge carrier 13 is not in the gun 1 in its service position presents a danger of accidental discharge, a protective shroud 13 can be fixed thereto and arranged such that the actuator 29 can access the locking element 21 via an access port 33a provided in the shroud 33, but it is difficult or impossible for this latter to be accidentally actuated otherwise.

[0070] In FIGS. 4-11, only reference signs of note and/or indicating features referred to herebelow are included, in order not to overload the figures.

[0071] FIG. 4 illustrates a variant of a pin 23b serving as projectile retaining element 23, primarily adapted to functionally replace the extremity 23a of the lever 23 of FIGS. 1-3, and its application in this role is illustrated in FIGS. 5, 7 and 11. This pin 23b comprises a cylindrical body 23c (though polygonal cross sections are also possible) and a radiused head 23d of rectangular profile adapted to cooperate with a corresponding radiused recess 23h provided in a lever 23g pivotably mounted on the body of the projectile carrier 13. The head 23d extends beyond the cylindrical body to limit the travel of the pin in the direction of the bore axis. The opposite end 23f of the pin 23b is cut conically to engage with a conical retaining surface of the groove 15a on the projectile 15.

[0072] This arrangement provides a good contact surface between the pin 23b and the retaining surface in the groove 15a on the projectile 15, enabling relatively high pressures to be withstood without damaging the material of the projectile 15, as is the case with ball bearings.

[0073] To retain the pins 23b, each lever comprises a distal extremity 23i which cooperates with a tubular locking element which can be as in FIGS. 1-3, or may, as illustrated in FIG. 5, simply comprise an angled surface cooperating with a corresponding angled surface at each distal extremity 23i.

[0074] FIG. 6 shows a nonlimiting manner in which the pin 23b can be prevented from rotating about its axis. As illustrated, the pin 23b comprises a longitudinal groove 23j in its body 23c, in which a guide pin 23k carried by the projectile carrier 13 runs so as to prevent the rotation of the pin 23b and to delimit its extreme positions parallel to its own axis. Alternatively, the pin 23b can carry the guide pin 23k, and the groove can be provided in the projectile carrier 13.

[0075] FIG. 7 illustrates two variations of arrangements for blocking the pin 23b in its engaged position. In the upper half of the figure, the arrangement is as in FIG. 5 and hence need not be described further.

[0076] In the lower half of the figure, the head 23d of the pin 23b comprises a camming face 23m which cooperates with a further camming face 23n formed at a first extremity of a locking arm 230 arranged to move linearly in translation, guided by a pin and slot arrangement 23p, and held in place by the sliding sleeve locking element 21. Movement of the sliding sleeve in the direction of projectile travel (indicated with the arrow) allows the force exerted by the projectile 15 (not illustrated on this figure) on the pin 23b to cam the locking arm 230 in the same direction, allowing the pin 23b to move out of engagement with the projectile 15.

[0077] FIG. 8 illustrates a manner of sealing the body 23c of the pin 23b to the side wall of the projectile carrier 13. An O-ring seal 35 is provided in such a manner as to seal the body 23c to the projectile carrier 13, retained in place by a retaining element 37. As illustrated, the O-ring seal 35 is provided in a recess in the projectile carrier 13, but it could also be provided in a groove in the pin body 23c. This arrangement minimises gas leakage upon projectile launch.

[0078] FIG. 9 illustrates a further variant in which the pins 23b act on the curved surface of the nose of the projectile 15 which hence acts as retention surface 15a, and are retained hydraulically.

[0079] The pins 23b are guided by a slot and guide pin arrangement similar to that used with an AR-15 rifle ejector and which hence need not be described in detail. The ends of the pins 23b are situated in an annular plenum chamber 13c provided in the projectile carrier 13 and filled with hydraulic fluid. Pin return springs 39 of any convenient type (e.g. coil springs) bias the pins 23b towards their engaged positions, and seals 35 are provided as in FIG. 8.

[0080] In this configuration, the locking element 21 is a plunger 21d which is situated in a plunger bore 13d which is in fluidic communication with the plenum chamber 13c. The plunger 21d is sealed to the plunger bore 13d by means of a plunger seal 13f. As a result, the plunger 21d and hydraulic fluid in the plenum chamber 13c can displace each other as is generally known in the field of hydraulics.

[0081] In the situation illustrated in FIG. 9, the force that the projectile 15 exerts on the pins 23b tends to cause them to retract, and thereby move into the plenum chamber. This is resisted by the hydraulic fluid and the plunger 21d, which is held in position by a sear abutment 29a serving as actuator 29. Movement of the sear abutment 29a away from the projectile bore allows the plunger 21d to move away from the plenum chamber 13c, allowing the pins 23b to retract and free the projectile 15.

[0082] FIG. 10 illustrates yet another arrangement, in which the retaining element 23 comprises a plurality of levers formed as a collet 23p, cooperating with the projectile 15 as in FIG. 9. Alternatively, the ends of the levers forming the collet 23p can cooperate with the projectile 15 as in FIGS. 1-3. The open end of the collet 23p cooperates with the sliding sleeve locking element 21 as in FIG. 5.

[0083] Finally, FIG. 11 partially illustrates a variant of FIG. 5 in which the lever 23g is maintained in position by a sliding sleeve locking element 21 as before, this latter being retained by a pivoting lever 29b itself being held by a sear 29c, these latter two elements constituting the actuator 29.

[0084] Although the invention has been described in terms of specific embodiments, variations thereto are possible without departing from the scope of the invention as defined in the appended claims.