SOUND SUPPRESSOR FOR A FIREARM

Description

FIELD

The present invention relates to sound suppressors. More particularly, it relates to firearm sound suppressors with enhanced water drainage capabilities.

BACKGROUND OF THE INVENTION

Firearm sound suppressors have existed since the late 19th century, and typically include an outer casing of tubular form, adapted to be attached at the muzzle of a firearm, defining a passage aligned with the bore axis to allow the projectile to pass through and exit the suppressor. In its simplest form, as disclosed in CH5755, the outer casing defines a single expansion chamber for allowing the propellant gases to expand and reduce their pressure before exiting to the atmosphere, reducing the intensity of the sound report produced as the relatively high-pressure gases leaving the muzzle exit into the relatively low-pressure atmosphere.

From this simple basis, a great variety of more effective suppressors have been developed over the years, typically dividing the inner space within the casing into multiple compartments, in order to slow the expansion of the propellant gases by disrupting their flow and/or forcing the flow to change direction with one or more of baffles, swirl chambers, spiral diffusers, and so on.

In recent years, suppressors have become more and more relevant in both civilian, police and military applications, in order to protect the hearing of the user and/or nearby persons, as well as to reduce the signature of firing a shot from the downrange perspective in applications in which this is relevant.

A particular difficulty is encountered in roles in which the suppressor may become submerged in water, such as in wildfowl hunting (or other hunting over water) and certain police or military applications. In all of these cases, the suppressor may become accidentally submerged and waterlogged, and in a military diver context, the entire firearm is typically required to be submerged during operations. Furthermore, it is also known to deliberately wet the inside of the suppressor to improve the sound attenuation for the first few shots, which also risks the suppressor being waterlogged if it is wetted by being immersed in water.

If a suppressor is waterlogged when the firearm is discharged, there is a high risk of damage to the suppressor and/or the firearm. Waterlogging of a suppressor inhibits the intended propellant gas flow in the suppressor, presents a significant additional mass which needs to be displaced by the propellant gases, and hence increases the pressure in the suppressor, which may cause it to burst or otherwise be damaged. Furthermore, even in the case in which it is not damaged, the suppressive effect is reduced since the effective working volume of the suppressor is reduced. This increase in pressure in the suppressor can also increase the chamber pressure of the firearm, and/or the port pressure in case of a gas operated firearm, also causing a risk of damage to the firearm.

U.S. Pat. No. 11,614,298 discloses a suppressor which can allegedly be drained in 2 seconds when the firearm to which it is mounted is pointed downwards, largely exceeding the 8 seconds typically required by military users.

However, if the firearm is not pointed downwards, full drainage cannot occur. This has the result that if the user forgets to orient the firearm appropriately, is unaware that the suppressor is waterlogged, or has to fire a shot very rapidly after leaving the water, the above-mentioned risks are still present. Furthermore, since the suppressor has to drain through its end cap, this places limitations on the configuration and design of the core, in order to favor drainage at the expense of suppression, and as a result, the level of suppression attainable is reduced compared to conventional designs.

The aim of the present invention is hence to at least partially overcome the above-mentioned drawbacks of the prior art.

BRIEF SUMMARY OF THE INVENTION

More specifically, the invention relates to a firearm sound suppressor as defined in claim 1. The firearm sound suppressor includes a tubular casing of any convenient form, having a proximal end adapted to be attached at the muzzle of a firearm, a distal end including an end cap (which may be a separate part or monolithic with the casing) with an exit orifice adapted to permit the passage of a projectile; a core structure of any convenient type situated in the interior of said tubular casing and defining at least one flow disruptor (typically several flow disruptors) adapted to disrupt flow of propellant gases leaving said muzzle, said core structure furthermore defining a projectile passageway adapted to be aligned with a bore of said firearm and adapted to permit the passage of a projectile from said muzzle to said exit orifice. The core structure may be a separate part, or may be monolithic with the casing; a plurality of water drainage openings passing through said tubular casing on an underside thereof, where “underside” is to be understood as the part of said casing intended to be oriented downwards during normal use of the suppressor; and a shutter including a plurality of through-holes, said shutter being slidably mounted on said casing and displaceable from a first position, in which said drainage openings are aligned with respective through-holes so as to permit water drainage, and a second position, in which said water drainage openings are occluded by said shutter, thereby closing off the water drainage openings for maximum suppressive effect.

As a result, when the shutter is in its first position, water present in the interior of the casing can drain rapidly without requiring the suppressor to be oriented downwards, enabling a safe shot to be fired more rapidly. Also, this arrangement permits rapid draining of suppressors without compromising on core design, since the requirement for water flow out of the end cap is eliminated and hence the core design can be optimised simply for suppression performance.

Advantageously, said core structure includes a plurality of baffles defining a plurality of expansion chambers, at least some of said expansion chambers having at least one corresponding drainage opening in fluidic communication therewith, i.e. opening thereinto. Typically, each expansion chamber situated behind a baffle (i.e. considered towards the proximal end of the casing) has at least one corresponding drainage opening.

This ensures that the expansion chambers can drain optimally.

Advantageously, said shutter is adapted to slide in a plane containing a longitudinal axis of said projectile pathway, preferably parallel to said axis. This is a simple construction, and is easy for the user to operate in order to move the shutter from one of its positions to the other and vice-versa. However, other configurations of shutter are of course possible.

Advantageously, said shutter is adapted to be moved manually from said first position to said second position, e.g. by acting on a manipulation element.

Furthermore, said shutter may be adapted to be moved from said first position to said second position by action of propellant gas pressure, for instance propellant gas pressure inside said casing, causing the drainage openings to be closed automatically upon discharging the firearm, if the shutter has been left in its first position. This may be achieved by fixing the shutter to a sliding blast baffle (i.e. the closest baffle to the muzzle of the firearm) situated within said casing, in which case the the shutter's first position is closer to the proximal end of the casing and its second position is closer to the distal end of the casing.

In a variant, the shutter extends beyond said end cap when in said first position, and the shutter is substantially flush with said end cap when in said second position, enabling the suppressor to be pushed against an object in order to close the drainage openings rather than requiring a manipulation of the shutter by the user's hand.

Advantageously, at least two, preferably all three, of said casing, said end cap and said core structure are monolithic, which is particularly useful for fabrication by modern additive manufacturing techniques.

Advantageously, each of said first position and said second position are stable positions defined by a detent system of any convenient type, which may be a locking-type detent or not, and the shutter may be lockable by the detent system in either the first position, the second position, or both, hence requiring a positive action by the user, e.g. on a release catch.

Advantageously, said detent system is adapted to permit said shutter to move from its first position to its second position by force applied to said shutter, and wherein an action on a release catch is required to permit said shutter to move from its second position to its first position. This prevents accidental opening of the drainage openings, while permitting a simple, fast closure thereof by force alone without requiring a catch to be actuated. More specifically, in such a case, the detent system may include a lever pivotally mounted on said shutter and including an extremity adapted to cooperate with each two notches provided on the tubular casing and/or endcap so as to define said first position and said second position. This solution is simple to construct, and simple in usage.

The above-mentioned features can be combined in any manner which makes technical sense.

BRIEF DESCRIPTION OF THE DRAWINGS

Further details of the invention will become apparent upon reading the following description, in reference to the appended figures, which illustrate:

FIG. 1: a longitudinal cutaway view of a suppressor according to a non-limiting embodiment of the invention, with the shutter in its first (open) position;

FIG. 2: a longitudinal cutaway view of the suppressor of FIG. 1, with the shutter in its second (closed) position;

FIG. 3: an isometric view of the suppressor of FIG. 1, with the shutter in its first (open) position, oriented to illustrate the shutter and the associated rail;

FIG. 4: a schematic longitudinal cross-section of a further non-limiting embodiment of the invention, with the shutter in its first (open) position;

FIG. 5: a schematic longitudinal section of the embodiment of FIG. 4, with the shutter in its second (closed) position;

FIG. 6: a lateral, partially-cutaway view of a firearm fitted with a suppressor according to the invention, the handguard and barrel being partially cut away to show the bore; and

FIG. 7: two simplified, partial schematic isometric views of a variant of a suppressor according to the invention, with a shutter sliding on a curve, in its second position (closed) in the upper portion of FIG. 7, and in its first position (open) in the lower portion.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1-3 illustrate a first nonlimiting embodiment of a suppressor 1 according to the invention.

Suppressor 1 includes a tubular casing 3, extending along a longitudinal axis A corresponding to an axis of a projectile pathway. Casing 3 is adapted to be attached at its proximal end 3a at the muzzle 101 of a firearm 100 (see FIG. 6) by means of a muzzle adaptor 5 of any convenient type, as is generally known, such that axis A is coaxial with the bore 103 of said firearm 100, that is to say the interior of the firearm's barrel 105, which may be rifled or smooth-bored. In the illustrated embodiment, adaptor 5 is of the type which interfaces with a muzzle device and is held in place with a locking ring 5a, but any known type of interface is possible, for instance a threaded adaptor intended to be screwed onto a threaded muzzle, a bayonet-type attachment adaptor (e.g. an HK-style tri-lug attachment), a collet-type frictional adaptor, a NATO-type adaptor, etc.

In the illustrated embodiment, casing 3 is of substantially circular internal cross-section, coaxial with axis A. However, other cross-sections such as oval, prismatic or more complex cross-sections are possible, and the outer sidewall of the casing 3 does not need to be coaxial with axis A, asymmetric configurations being well-known to the skilled person.

Distal end 3b of the tubular casing 3, i.e. the end which is free and not attached to the barrel 105 of the firearm 100 when the suppressor 1 is mounted thereupon, is provided with an endcap 7, defining an exit orifice 9 adapted to permit the passage of a projectile leaving the firearm's muzzle 101, and to this end is of a suitable diameter and is aligned with the axis A. The exact configuration of exit orifice 9 is not important for the present invention and need not be described in detail, and further openings may also be provided in the endcap 7.

Internally, the casing 3 contains a core structure 11, designed to disrupt the flow of propellant gases leaving the muzzle 101 of the firearm 100. In the illustrated embodiment, this core structure includes three conical-shaped baffles 11a, 11b, 11c, with openings 13a, 13b, 13c aligned with axis A and defining a projectile passageway adapted to permit a projectile leaving the muzzle 101 of the firearm 100 to pass through and leave the suppressor 1, as is generally known.

Baffles 11a, 11b, 11c act as flow disruptors, and define a plurality of expansion chambers 15a, 15b, 15c, 15d, as is generally known. However, it should be noted that the exact nature of the core structure 11 is unimportant to the present invention, and this can take any known form based on one or more flow disruptors adapted to act upon expanding propellant gas to affect its flow. Such core structures 11 may be of a conventional baffle-type configuration, or may be of the reduced backpressure type defining a core flow and an outer bypass flow, such as described in EP3489613, for instance. In essence, the present invention can be applied to any known type of core structure 11 and is not limited to any particular configuration thereof.

In the illustrated embodiment, the casing 3, end cap 7 and core structure 11 are of unitary, monolithic construction, fabricated by additive manufacturing (so-called “3D printing”) such as selective laser sintering or similar. However, this does not have to be the case, and these elements can be separately fabricated and assembled conventionally, e.g. by welding, threading, pinning, bonding and any other suitable technique. It should also be noted that the full range of suitable materials (metals such as steels, aluminium, titanium, Inconel etc., ceramics, polymers, carbon fibre etc.) can be used for the components of the suppressor 11 according to the invention and according to end user requirements.

The key to the present invention lies in the provision of a plurality of water drainage openings 17a, 17b, 17c in the underside of the casing 3, adapted to permit water to drain out from inside the casing 3 through the sidewall thereof.

The term “underside” is to be understood as relating to the portion of the casing 3 which is intended to be oriented facing directly towards the ground when the suppressor 1 is correctly mounted on a firearm 100 (see FIG. 6), and the firearm 100 is held upright with its barrel 105 (and hence axis A) horizontal to the ground. In the usual case of a bottom-mounted magazine 107 and top-mounted sighting system 109 both provided in a single plane, this plane is hence oriented vertically with the sighting system 109 and hence the line of sight S uppermost with respect to axis A, with the underside of the suppressor 1 facing directly away from the line of sight S. The skilled person understands how “underside” is defined for less common arrangements, e.g. where the sighting system 109 and/or magazine 107 is not in the conventional location (or are indeed absent), and is hence offset from the vertical plane. As illustrated, the “underside” of the casing 3 is the portion directed towards the bottom of the page. If the user wishes to hold the firearm 100 canted, the suppressor 1 can, of course, be oriented accordingly such that the drainage openings 17a, 17b, 17c are oriented downwards in this situation.

Advantageously, the drainage openings 17a, 17b, 17c are the only lateral openings provided in the casing 3 and are situated only in the underside of the casing 3, but further occludable openings at other positions on the casing are not excluded. As illustrated, the drainage openings 17a, 17b, 17c are arranged in a single line parallel to the axis A, although they may be arranged in a staggered pattern, in pairs, triples or similar. More generally, the drainage openings 17a, 17b, 17c are all situated within a (geometric) sector of 120°, preferably 90° or less of the casing 3 on the underside thereof (as defined above), preferably within a sector of 45° or less, further preferably within a sector of 15° or less, said sector having its origin on the axis A.

Drainage openings 17a, 17b, 17c are selectively closeable by a shutter 19, slidably mounted on casing 3, each of which opens into a respective expansion chamber 15a, 15b, 15c behind a corresponding baffle 11a, 11b, 11c. However, this is not obligatory: multiple drainage openings per expansion chamber are possible, and in the case of a bypass flow suppressor, a suitable number of drainage openings may simply be provided, distributed along the length of the casing 3 at suitable locations.

In the illustrated embodiment, shutter 19 is slidably mounted in a rail 23 provided on the exterior of the casing 3, such that it can slide rectilinearly in a plane containing axis A, more particularly parallel to axis A due to the fact that the casing 3 is of substantially tubular cylindrical cross-section with parallel sidewalls. However, the application of the principle of the invention to suppressors 1 with tapered casings 3 is not excluded. Furthermore, the shutter 19 can be provided in the interior of the casing 3, guided by any suitable support arrangement.

Shutter 19 includes a plurality of through-holes 21a, 21b, 21c, which communicate fluidically with respective drainage openings 17a, 17b, 17c when the shutter 19 is in a first position (as illustrated in FIG. 1), and preferably have a diameter at least as that of the corresponding drainage openings 17a, 17b, 17c. When the shutter 19 is in this position, expansion chambers 15a, 15b and 15c are open to the atmosphere through the sidewall of the casing 3, and water present in the inside of casing 3 can drain out under the effect of gravity without having to orient the suppressor 1 vertically downwards, the openings 17a, 17b, 17c and through-holes 21a, 21b, 21c being sized appropriately to ensure water drainage within 8 seconds, preferably within 3 seconds, further preferably within 2 seconds. To this end, typical widths of the openings 17a, 17b, 17c and through-holes 21a, 21b, 21c is of the order of 3.5 mm to 8 mm, preferably 4.5 mm to 7 mm, and they may be formed as circular holes, slots, or any combination thereof. If a shot is fired with the shutter in this position, propellant gas will be expelled from the drainage openings 17a, 17b, 17c, the suppressive effect of the suppressor 1 will be significantly reduced, but no harm will come to the suppressor, the firearm or the user. In the case in which water has not yet fully drained from the interior of the casing 3, it will simply be expelled from the drainage openings 17a, 17b, 17c under pressure, again without causing harm to the suppressor, the firearm or the user.

When the shutter 19 is moved into its second position, as illustrated in FIG. 2, the through-holes 21a, 21b, 21c are no longer aligned with the respective drainage openings 17a, 17b, 17c, and these are hence closed (i.e. are occluded by the shutter 19) and the suppressor 1 functions as normal, with minimal loss of propellant gas by leakage through the drainage openings 17a, 17b, 17c and around the shutter 19.

In order to facilitate movement of the shutter 19 between its two positions, a manipulation element 24 is provided, shaped e.g. as a button, knob or any other convenient shape permitting the user to manipulate the shutter with fingers (whether gloved or not) or a suitable tool.

In the illustrated embodiment, each of the first and second positions of the shutter 19 are stable positions, and to this end a detent system 25 is provided. As illustrated, this detent system 25 takes the form of a lever 25, pivotally mounted on the shutter 19 and with an extremity 25a adapted to engage with a first notch 27 when the shutter 19 is in its first position, and a second notch 29 when the shutter is in its second position, the notches 27, 29 being provided on the casing 3 and/or endcap 7. In order to keep the extremity 25a of the detent lever 25 engaged with one or other of the notches 27, 29, a corresponding return spring 31 is provided, urging the extremity 25a into this engagement, and against which the user can act via action on a release catch 25b.

In the illustrated embodiment, the notches 27, 29 and the extremity 25a of the detent lever 25 are arranged such that the user does not need to press on the release catch 25b in order to bring the shutter from its first position to its second position, but does need to do so in order to bring the shutter from its second position to its first position. To this end, the angle of the surfaces of the notches 27, 29 is shallower with respect to axis A towards the proximal end 3a of the casing 3 than towards the distal end 3b thereof. As a result, the risk of the user accidentally opening the drainage openings 17a, 17b, 17c is reduced, whereas closing them is simple, requiring only force to be applied to the shutter 19.

However, this does not have to be the case: the notches 27, 29 and lever 25 can be arranged such that user must act on the release catch 25b in each case, or inversely, such that the user does not have to act on the release catch 25b, in which case it may be omitted. In such a case, a ball detent or other arrangement would naturally be suitable. Alternatively, it is also possible to arrange the detent lever 25 to lock the shutter 19 in its first position but not in its second position.

It goes without saying that other alternative constructions are also possible to define the two stable positions of the shutter 19, mounted either on the shutter 19 or the casing 3.

Another particularly advantageous feature of the shutter 19 as illustrated is that it protrudes beyond the end cap 7 when in its first position and is substantially flush with the end cap 7 when in its second position. As a result, the user can, in an emergency, bring the shutter 19 into its second position, and hence close the drainage openings 17a, 17b, 17c, by simply pushing the end of the suppressor 1 against an object.

However, this functionality is not obligatory, and the shutter 19 can be entirely within the rail 23 in each of its positions.

Furthermore, the shutter 19 can also be arranged to inverse its relationship with respect to the casing 3 in each of its positions, that is to say that it may be situated more towards the proximal end 3a in its first position and more towards the distal end 3b in its second position.

Also, other arrangements of shutter 19 are also possible, for instance as illustrated in FIG. 7, which shows a shutter 19 arranged to slide on a curve along the circumference of the tubular casing 3 in curved guide rails 23. To avoid overloading these figures, only one through-hole 21a and the corresponding drainage opening 17a have been indicated with reference signs. As illustrated, this curve follows an arc with its origin on axis A, but other solutions are also possible. Furthermore, the shutter 19 may be formed as a rotary sleeve sliding in rotation on the casing 3 about axis A, other forms of rotary sliding about any convenient axis, and many other configurations are equally possible. Furthermore, various types of actuator (linear, rotary, levers, camming etc.) for moving the shutter 19, whatever its configuration, between positions are also possible. Such actuators may be part of the suppressor 1, or may be part of, or attached to, the firearm 100 itself, and kinematically linked to the shutter 19.

FIGS. 4 and 5 illustrate schematically a further variant of a suppressor 1 according to the invention, with the shutter 19 respectively in its first and second positions. In this case, the first position has the shutter 19 nearer to the proximal end of the casing 3, and the second position has the shutter nearer the distal end 3b of the casing 3, for reasons which will become apparent.

In this embodiment, which will be described in terms of how it differs from the embodiment of FIGS. 1 and 2, five washer-type baffles 11a-e are provided, dividing the interior of the casing 3 into six expansion chambers 15a-f, the number of baffles being chosen as required. Each expansion chamber has at least one corresponding drainage opening 17a-h opening thereinto, three drainage openings 17f-h being provided in the larger, final expansion chamber 15f proximate to the distal extremity 3a. Muzzle adaptor 5 is of the conventional, threaded type, though any other type is of course possible. However, in the case in which water can flow from one chamber 15a-f to another, it is not obligatory that each chamber 15a-f be associated with at least one corresponding drainage opening 17a-h.

In the illustrated embodiment, the nearest baffle 11a to the proximal end 3a of the casing 3 (and hence to the adaptor 5 and the muzzle of the firearm when the suppressor 1 is attached thereto), hereafter referred to as the “blast baffle 11a”, is arranged to slide parallel to the axis A, and illustrated as having a cupped shape. The blast baffle 11a is fixed to the shutter 19, and is provided with an additional through-opening 33, aligned with the first drainage opening 17a when the shutter 19 is in its first position (as illustrated in FIG. 4). Alternatively, the blast baffle 11a can be arranged simply to not occlude the first drainage opening 17a in the first position, e.g. by being cut away or being of insufficient length to do so.

In this arrangement, if the user fires a shot while the shutter 19 is in its first position, the gas leaving the muzzle of the firearm will act upon the blast baffle 11a, forcing it forwards, i.e. towards the distal end of the casing 3. Since the blast baffle 11a is fixed to the shutter 19, this latter is likewise forced forwards, occluding the drainage openings 17a-h while minimising the escape of gas therethrough during this first shot.

In a non-illustrated variant, it is also possible to actuate the shutter via an actuator (such as a piston, recoiling mechanism or similar) provided in the firearm 100 itself, so as to automatically bring it into its second position.

The suppressor 1 of the invention can be used in the following manners.

In one mode of operation, the shutter 19 can be maintained in its second position, with the drainage openings 17a-c/17a-h hence being occluded. If the suppressor becomes submerged, the user can bring the shutter 19 into its first position, allowing water to drain from the interior of the casing 3, before returning it to its second position.

In a second mode of operation, in which it is known in advance that the suppressor 1 will be submerged, the user can place the shutter 19 in its first position before entering the water, and then, upon leaving the water and after a few seconds have elapsed to allow water to drain from the interior of the casing 3, can manually place the shutter 19 in its second position.

In a third mode of operation, the shutter 19 is placed in its first position, and the firearm 100 is discharged without placing the shutter 19 into its second position. In the case of the embodiment of FIGS. 1 and 2, this will result in the effectiveness of the suppression being significantly reduced. However, in the case of the embodiment of FIGS. 4 and 5, the propellant gas of the first discharge of the firearm 100 will cause movable blast baffle 11a to automatically move the shutter 19 into its second position, occluding the drainage openings 17a-h. This mode of operation is intended for emergencies, or in case the user forgets to place the shutter 19 into its second position before discharging the firearm 100.

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.