The present disclosure relates to a barrel unit for a firearm, comprising a barrel and a barrel extension which are detachably connected to each other and subsequently to the receiver, primarily the upper receiver part, and the connection of the two parts.
As used herein, the term firearm is understood as including, without limitation, handguns such as pistols, as well as long guns such as rifles, including carbines, and repeating rifles.
In recent years, military, law enforcement, and civilian users have increasingly demanded that it should be possible to exchange the barrel of a rifle without great effort. This can be done, for example, in order to be able to use barrels of different lengths, or barrels with different calibers, wherein the barrel axis/bore maintains its position in the receiver (upper part) for each caliber. In the latter case, optional changes may have to be made in the lower receiver part, but such changes are not part of the present disclosure.
Accordingly, modern firearms often have a barrel unit which comprises at least the barrel and the barrel extension. The barrel unit in turn can be connected to the receiver by means of, for example, a barrel nut, a clamping mechanism, etc.
A common variant for coupling a barrel with a barrel extension is the use of threaded connections. The barrel has an external thread at the end of the barrel remote from the muzzle, and the barrel extension likewise has a corresponding internal thread. For coupling the two, the barrel can simply be screwed into the barrel extension. The barrel can be secured against rotation by means of cross bolts or grub screws, etc. Such a coupling of the barrel with the barrel extension can be found, for example, in rifles of the M4/M16/AR15 type.
Another known variant for coupling the barrel and the barrel extension utilizes the principle of locking lugs, as is known, for example, from rotating bolts. Corresponding barrel lugs are formed on the outside in the circumferential direction, and the barrel extension has identical and opposite barrel locking lugs facing inwards. After the barrel has been inserted into the barrel extension, the barrel is rotated, thereby causing the barrel lugs and barrel locking lugs to come into an overlapping position when viewed in the axial direction. The barrel and barrel extension are thus secured in the axial direction. The barrel can be secured against rotation by means of a cross bolt or grub screw, etc.
An example of a firearm that utilizes this locking principle is the Steyr AUG rifle, which is designed to have the barrel extension as part of the receiver/breech. However, this securing takes place via a transverse bolt located in the receiver, which some users find difficult to use, especially in bad weather.
The previously known arrangements for attaching the barrel to a receiver are more or less well-suited for positioning the barrel in a predefined position with repeatable accuracy in the barrel extension, and thus relative to the receiver of the firearm.
What is needed, however, is a barrel unit with a mechanically strong connection, comprising the barrel and the barrel extension. Preferably, such a barrel unit would enable users to change a barrel in a way that can be carried out as simply as possible and without tools. Also desirable is a barrel unit that can achieve an installation situation in which the barrel is secured against rotation in the installed condition. Furthermore, it is seen as-advantageous to enable the barrel to be positioned with repeatable accuracy relative to the receiver. Additionally, such a barrel unit should lend itself to simplified, and thus cost-reduced, production methods.
The present disclosure is directed to barrel units for firearms, the barrel units including a barrel having a barrel axis, a muzzle, a barrel end opposite the muzzle, and at least two barrel lugs formed on the barrel end. The barrel unit further includes a barrel extension having a barrel receptacle, the barrel extension having a first end and a second end; where a plurality of inwardly extending locking lugs is formed on the first end of the barrel extension, the locking lugs being configured to work together with a bolt, and a plurality of inwardly extending barrel locking lugs formed on the barrel extension, the barrel locking lugs being formed closer to the second end than the inwardly extending locking lugs. The barrel has a cam on an outer surface that is configured to cooperate with a cam lug arranged on the barrel extension, the cam having a first portion and a second portion, the first portion being formed beginning at the end of the barrel and extending parallel to the barrel axis, and the second portion being at least partially formed in a circumferential direction around the barrel axis. The second portion of the cam has a locking surface that is complementary in shape to the cam lug, such that the cam lug and/or the locking surface are configured to be preloaded against each other in a radial direction to fix the barrel in a predefined end position.
The barrel unit of the present disclosure is explained in more detail below with reference to the drawings, wherein:
As used herein, the terms left, right, up, down, front and back in the following always refer to the firearm from the point of view of the firearm when it is held ready to fire. The weapon has, going through the barrel axis and oriented vertically, a weapon center plane, which cum grano salis, forms a plane of symmetry.
In the present disclosure and the claims, the terms “front,” “rear,” “above,” “below” and so on are used in the generally accepted form and with reference to the object in its usual use position. This means that, for the firearm, the muzzle of the barrel is “at the front,” that the breech is moved “rearward” by the explosive gas, etc. Transverse to a direction substantially means a direction rotated by 90°.
According to the present disclosure, these goals are achieved by a barrel unit that consists at least of the barrel and the barrel extension, has a cam beginning on the outer surface at the end of the barrel and extending at least partially around the circumference about the barrel axis. The cam comprises at least two portions, wherein the first portion starts at the end of the barrel and extends parallel to the barrel axis, and the second portion extends in the circumferential direction, and the second portion has a locking surface for bracing a cam lug arranged on the barrel extension. The locking surface and the cam lug (or the surface of the cam lug facing the locking surface) are designed to be complementary to each other. The second portion can be connected directly to the first portion, or a third connecting portion can be provided between them.
After being rotated into the second portion, the cam lug comes to lie in a predefined end position, wherein the cam lug is preloaded in the radial direction in the direction of the barrel axis, and the barrel is fixed in the barrel extension. The predefined end position thus corresponds to a position of the barrel that is ready to fire and is temporarily secured against rotation. The barrel is relatively easy to insert into the barrel extension as a result, and can be rotated into the predefined end position in which the barrel is detachably fixed to the barrel extension due to the bracing of the cam lug against the locking surface.
This advantageous embodiment allows the barrel and the barrel extension to be connected to each other simply by inserting one into the other and rotating them into the predefined end position. In the predefined end position, the barrel can transmit the forces that occur when a shot is fired to the barrel extension, which in turn is fixed to the receiver. Whereas with a threaded connection the alignment in the circumferential direction strongly depends on how far the barrel is screwed into the barrel extension, any deviations in the impact position in the horizontal and/or vertical direction can be minimized in the aforementioned way.
If the impact position is then determined for a specific barrel and the firearm is therefore “sighted in” for a given distance, the predefined end position can be used to position the barrel with repeatable accuracy in the circumferential direction even after the firearm has been dismantled. If necessary, the barrel can be detached from the barrel extension relatively easily by rotation in the opposite direction. No tools are required to connect and disconnect the barrel and the barrel extension.
The preloaded fixation of the cam lug against the locking surface can take place, for example, by preloading a spring of the cam lug. The cam lug can, however, also be made of an elastic material. However, it is also possible to reverse the direction of action and, for example, to design the locking surface (or even the locking surface and the cam lug) as a spring-loaded element.
In a particularly advantageous embodiment, the locking surface is designed as a ramp, when viewed in the barrel direction. When viewed in the barrel direction, the locking surface has a different normal distance from the barrel axis at one end than at the other end. As a result, a stepless transition from the cam to the locking surface can be achieved and the barrel can be easily rotated into a predefined end position. Furthermore, the clamping effect upon rotation can increase in a defined manner with a corresponding design of the shape and/or slope of the ramp, and therefore can be easily perceived by the operator.
In a further advantageous embodiment, the ramp of the locking surface, is designed to rise linearly outward in the radial direction when viewed in the direction of the end of the cam. The locking surface therefore rises linearly in the circumferential direction and outwards, which is advantageous in terms of manufacture.
In another particularly advantageous embodiment, the second portion of the cam, can be curved, and for example, S-shaped, when viewed in the barrel direction, with at least two different curved lines. The clamping effect upon rotation can be specifically preset by a person skilled in the art by means of a measure of this type—for example, as a function of the rotation angle—and can be defined with a variable magnitude, and/or can be optimized for particularly long barrels with corresponding weight.
It is also possible to design the locking surface as a curved surface, for example as a surface that is concave relative to the barrel surface. The clamping effect can be particularly optimized in this way. When designed as a concave surface, the profile of the surface appears curved when viewed in the barrel direction and can, for example, have an inward curvature and/or rise discontinuously outward from the transition area to the first section and/or any third section, up to the end of the locking surface. In this way, it is even possible to design this concave surface in a manner similar to a detent, so that the operator can easily recognize when the predefined end position is reached.
In a further special embodiment, a detent which works together with the cam lug or a detent protrusion of the cam lug is formed on the locking surface. The detent can be designed as a small recess, for example in the center of the locking surface. A corresponding complementary detent protrusion on the cam lug can engage in this detent when the predefined end position is reached, and thus define the end point of the rotation movement. The user can therefore easily recognize when the predefined end position has been reached. The detent can also be designed as a small step at the beginning of the locking surface, which works together with the cam lug. The detent can also be designed as an end catch at the end of the cam.
In another special embodiment, an end catch can be formed on the locking surface. This end catch limits the possible movement of the cam lug in the second portion of the cam in the circumferential direction. This makes it particularly easy for the user to recognize the predefined end position, specifically when the end catch is reached.
It has proven to be particularly advantageous if the first portion and the second portion of the cam are connected to each other by means of a connecting portion, or preferably directly connected. This form of the cam and/or its first portion is particularly easy to manufacture since, for example, only one groove running linearly to the rear, and one groove in the circumferential direction, have to be milled. This is also advantageous when the barrel and the barrel extension are guided into each other, since the barrel and the barrel extension can be inserted straight into each other and rotated, and as such, the predefined end position can be reached. It is incumbent on the person skilled in the art to design the second portion directly adjoining the first portion, or to optionally form the rotation path from the first to the second portion, and thus up to the locking surface, by means of a connecting portion in order to design the optimal position and orientation of the locking surface relative to the first portion, the insertion portion. This can be advantageously exploited, particularly for the optimization of the weight of the barrel and its oscillation behavior when a shot is fired.
In addition, it is particularly advantageous if the second portion of the cam is formed at a right angle to a straight line parallel to the barrel axis. After they have been guided into each other, the barrel and the barrel extension only need to be rotated relative to each other in order to reach the predefined end position. A second portion designed in this way can likewise be manufactured very easily as a linear groove in the circumferential direction, for example by means of milling, and essentially corresponds to an “L-shape” when viewed from above and outside.
Furthermore, a particularly favorable design of the barrel unit can have a first distance between two adjacent barrel lugs which is greater than a second distance between two adjacent barrel lugs. The first distance can essentially correspond to the width of the cam lug. The width of the cam lug must be smaller than the first distance and should be greater than the second distance. The result of this design is that the barrel and the barrel extension can only be inserted into each other in exactly one specific orientation, specifically when the cam lug is aligned with the first distance between two adjacent barrel lugs. If the cam lug and the first distance do not coincide, the cam lug can be brought into overlap with the first distance by simply turning the barrel. Then the barrel can simply be inserted into the first portion of the cam. Ideally, the barrel is inserted with the muzzle pointing vertically upwards, and only needs to be gently gripped above the barrel extension so that, when the cam lug is in the correct position, it slides into the cam by itself due to gravity.
It has proven to be particularly advantageous if the cam lug is arranged in the barrel extension by means of a cam lug retainer. The cam lug can be connected to the cam lug retainer as a unit, that is to say, designed as a separate “sub-assembly”, which is thus installed in the barrel extension together and at the same time. This is advantageous in terms of manufacture and handling.
Furthermore, it can be particularly advantageous if the cam lug is formed integrally with the cam lug retainer. This reduces the number of parts, and accordingly the production is simplified and the production costs are reduced. Assembly is quicker, and easy-to-lose parts are avoided. For example, the cam lug can be manufactured integrally with the cam lug retainer, for example as a stamped sheet metal part.
Furthermore, it is particularly advantageous if the cam lug retainer is designed as a spring, particularly preferably as a leaf spring, and preloads the cam lug in this way in a predefined end position against the locking surface. A leaf spring can also be arranged in the barrel extension even if there is only little space; in addition, leaf springs are generally highly resilient and particularly wear-resistant. The spring preload produces a particularly high clamping effect in the predefined end position, which is particularly advantageous when the firearm is operated.
In a further, particularly favorable embodiment, the cam lug retainer can be connected in the working position to the barrel extension in a self-clamping and detachable manner. Tight tolerances between the cam lug retainer and the barrel extension produce the self-clamping effect, which allows a connection without connecting elements such as screws, etc., and if necessary the cam lug retainer can be released from the barrel extension and exchanged. For example, small lateral protrusions, which are brought into a corresponding retainer groove in the barrel extension, can be formed on the cam lug retainer. The self-clamping effect is achieved by the close tolerance between the protrusion and the retainer groove.
It is also possible and particularly advantageous that a retainer catch is designed on the cam lug retainer to engage in a notch on the barrel extension in order to secure the cam lug retainer in the working position in the barrel extension. The cam lug retainer is thus secured against axial displacement, and thus against loss from the barrel extension.
A further aspect of the present disclosure is that the barrel has a notch which can work together with an additional anti-rotation element that is designed to be complementary in shape. Such an additional anti-rotation protection of the barrel can be implemented, for example, by means of a bolt positioned transverse to the barrel axis.
It can be particularly advantageous if the additional anti-rotation element is designed as a nose of a tension lever, which is designed to be complementary in shape to the notch. The notch can, for example, be designed as a flat notch in the barrel. The nose can be designed in this case to be flattened in the transverse direction and/or in the barrel direction. In this way, when there is contact between the barrel and the nose, force is transmitted along a line or along a surface, which results in improved anti-rotation protection. This is particularly advantageous in designs in which the barrel extension is already connected to the receiver by means of a clamping mechanism with tension lever.
It is particularly positive if, when in the ready-to-fire position, the nose and the flat are spatially separated from each other by a clearance, the clearance preferably having a width of 0.02 mm to 0.4 mm, and a particularly preferable width of 0.10 mm to 0.20 mm. The clearance ensures that the barrel is mounted so that it can swing freely and is not undesirably clamped by the nose. As such, the anti-rotation protection only works in the event that the barrel is actually rotated.
The barrel unit described herein is suitable for firearms, and therefore also for pistols, but is explained below using the example of a rifle. Further components of the firearm, such as the barrel, cartridge chamber, barrel extension, locking lugs, magazine or buttstock are not explained in more detail here, since they do not concern the core of the disclosed barrel unit, and a person skilled in the art can make modifications simply on the basis of his specialist knowledge, with knowledge of the present disclosure, if necessary or desired at all.
In the figures described below, the barrel direction is indicated by the arrow 91 as forward, the normal direction is indicated by the arrow 93 as upwards, and the transverse direction is indicated by the arrow 92 as left.
Inwardly extending locking lugs 31 corresponding to the prior art, and a locking space 32 behind them, extending in the direction of the second end, are formed in the cylindrical opening on the first end of the barrel extension 3. These can work together with a bolt (not shown), for example a rotating bolt and its bolt end.
Furthermore, barrel locking lugs 35 which extend inward are formed on the barrel receptacle 33, and are arranged closer to the second end of the barrel extension 3 than the locking lugs 31. Corresponding to the prior art, barrel locking lugs 35 can work together with barrel lugs 15 of a barrel 1, of complementary shape, and in this way strongly couple the barrel 1 and the barrel extension 3 to each other in the axial direction.
Furthermore, a cam lug 36 extending inward into the barrel receptacle 33 is formed on the barrel extension 3, and can be arranged closer to the second end than the barrel locking lugs 35. The cam lug 36 is preferably designed as a separate part, or is formed on a separate part, and is spring-loaded. In a preferred and illustrated embodiment, the cam lug 36 is arranged on a cam lug retainer 321 or is formed integrally with it. The cam lug 36 with the cam lug retainer 321 is arranged in a retainer receptacle 322 of the barrel extension 3, for example. The cam lug 36 can preferably be spring-preloaded, for example by the cam lug retainer 321 being designed as a leaf spring. Other alternative designs are also possible. The cam lug 36 can be designed as a spring-loaded pressure piece or as a bolt with a compression spring, or as an elastic element. It is also conceivable to arrange the cam lug retainer 321 in the barrel extension 3 with a spring load.
However, it is also conceivable to connect the barrel unit according to the invention to the receiver 2, for example by means of a barrel nut or thread.
A flat notch 115 formed on the barrel 1 can also be seen in
The locking surface 161 can, however, be designed in the shape of a curve when viewed in the normal barrel direction 91. Alternatively, locking surfaces curved in two dimensions are also possible. For example, the slope and/or shape of the locking surface 161 when viewed in the normal barrel direction 91 can be progressive or concave, degressive or convex, or S-shaped, etc.
Furthermore, the locking surface 161 can have a detent to lock the cam lug 36. This detent can, for example, be arranged in the center of the locking surface 161. The cam lug 36 can optionally have a corresponding detent protrusion, wherein the cam lug 36 and/or the detent protrusion are designed to be complementary in shape to the detent. The locking surface 161 can additionally have an end catch on its end (at the end of the cam 16), which limits the movement of the cam lug 36 in the second portion of the cam 16, as can be seen very clearly in
The first portion of the cam 16 is preferably designed as a surface parallel to the barrel axis 11. The second portion of the cam 16 preferably directly adjoins the first portion. The second portion is preferably designed in such a manner that its projection in the normal direction 93 to the barrel axis 11 is at a right angle to the barrel axis 11.
The arrangement can be described in the most easily imagined form in such a way that, with a uniform, i.e. symmetrical, distribution of equally-wide barrel lugs 15, with the second width 154 (and always with the same second distance 152), material is removed from the inside of two adjacent barrel lugs 15. As a result, the width of the two adjacent barrel lugs 15 is reduced to the first width 153. The distance in between increases to the first distance 151. This (imaginary) material removal is indicated by a dotted line on the barrel lug at the 12 o'clock position.
As shown, in a preferred embodiment, eight barrel lugs 15 are formed at the end of the barrel 1 in each of two rows positioned one behind the other (and accordingly, two rows of eight barrel locking lugs 35 are formed in the barrel extension 3); the barrel lugs 15 and the barrel locking lugs 35 are preferably the same width. The disclosed barrel unit can, however, also be carried out with a different, lesser or greater, number of barrel lugs 15 and corresponding barrel locking lugs 35. In particular, the widths of the barrel lugs 15 can be the same and, in accordance with the above-described embodiment, the first and second distances 151, 152 can be achieved by a corresponding arrangement of the barrel lugs 15 in the circumferential direction.
To couple the barrel 1 with the barrel extension 3, the barrel 1 is pushed into the barrel receptacle 33 of the barrel extension 3 with the end of the barrel 1 first, and the cam lug 36 is made to overlap with the first distance 151 by rotating it. The barrel 1 can now be moved further into the barrel extension 3, guided by the cam lug 36 in the cam 16. When the cam lug 36 is at the end of the first portion of the cam 16, the cam lug 36 can be braced against the locking surface 161 by rotating the barrel 1, and the predefined end position is thus reached. In the predefined end position, when viewed in the axial direction, the barrel lugs 15 and the barrel locking lugs 35 overlap in order to transfer the forces that occur when a shot is fired from the barrel 1 to the barrel extension 3 and subsequently to the receiver 2 of the firearm. In the predefined end position, the barrel 1 is detachably fixed to the barrel extension 3, that is, coupled.
A clamping assembly 4 with a tension lever 40 and a grip 43 can detachably fix the barrel unit to a receiver 2 (not shown), and is in the ready-to-fire state. The nose 41 engages through the recess 371. The associated detailed view, labeled as IX, is shown in
In complement to
For a better understanding of the mounting of the cam lug retainer 321, attention is directed to an oblique view in
Furthermore, it is possible to form a flat notch 115 on the barrel 1 which works together with an additional anti-rotation element which is designed to be complementary in shape. For example, it is possible to implement such an additional anti-rotation protection (for the barrel 1 and the barrel extension 3) by means of a bolt which is arranged in the barrel extension 3 or in the receiver 2 transverse to the barrel axis 11, and which engages in the flat notch 115.
Another preferred embodiment is described below in
The barrel 1 has a flat notch 115 on a side facing the nose 41 in the ready-to-fire state. Depending on the shape of the nose 41, other shape-complementary recesses can also be formed. In the ready-to-fire position, the barrel 1 should be spaced from the tip of the nose 41 by a clearance 416 in the region of the flat notch 115; see also
Due to the shape-complementary design of the flat notch 115 of the barrel 1, the tension lever 40 can only be closed when the barrel 1 is aligned in a predetermined position in the barrel extension 3. A kind of “end position verification” of the barrel 1 can thus be achieved in a simple manner. It has proven to be advantageous if the clearance 416—if provided—is only a few hundredths of a millimeter, preferably 0.02 to 0.40 mm, particularly preferably from 0.10 to 0.20, as can also be clearly seen in the detail view in
The present disclosure is not limited to the illustrated and described exemplary embodiments, but can be modified and configured in various ways. In particular, the shapes and sectional shapes shown of the named weapon parts, in particular the barrel, cam, barrel lugs, barrel extension, barrel locking lugs, cam lug, cam lug retainer, tension lever, distances, widths, recesses, etc. can be adapted to the specific basic data, and the lengths and the positions relative to each other, and with regard to the receiver, are easily adaptable for a person skilled in the art with knowledge of the disclosed barrel unit. In particular, equivalent designs are obvious with knowledge of the disclosed barrel unit and can be carried out without further ado by a person skilled in the art. In particular, the named embodiments are mutatis mutandis to be applied to embodiments with the opposite direction of action of the locking surface and cam lug, and/or biasing of both elements.
It should also be noted that in the description and the claims, terms such as the “lower region” of an object, refer to the lower half and in particular the lower quarter of the overall height; “lowermost region” refers to the lowermost quarter and in particular an even smaller part, while “central region” refers to the central third of the overall height. For the terms “width” and/or “length,” this applies mutatis mutandis. All these terms have their generally accepted meaning, applied to the intended position of the object under consideration.
In the description and the claims, “substantially” means a deviation of up to 10% of the stated value, if physically possible, both downward and upward, otherwise only in the appropriate direction; in the case of degrees (angle and temperature), and for indications such as “parallel” or “normal,” this means ±10°. If there are terms such as “substantially constant” etc., what is meant is the technical possibility of deviation which the person skilled in the art takes as a basis and not the mathematical one. For example, a “substantially L-shaped cross-section” comprises two elongated surfaces, which merge at one end into the end of the other surface, and whose longitudinal extension is arranged at an angle of 45° to 120° to each other.
All given quantities and percentages, in particular those relating to the limitation of the disclosure, insofar as they do not relate to specific examples, are understood to have a tolerance of ±10%; accordingly, for example: 11% means 9.9% to 12.1%. With terms such as “a solvent,” the word “a” is not to be considered to represent a singular numeral, but rather is to be considered an indefinite article or pronoun, unless the context indicates otherwise.
Unless otherwise stated, the term “combination” and/or “combinations,” means all types of combinations, starting from two of the relevant components up to a plurality or all of such components; the term “containing” also means “consisting of.”
The features and variants stated in the individual embodiments and examples can easily be combined with those of the other examples and embodiments and in particular can be used for characterizing the disclosed barrel unit in the claims without necessarily including the other details of the particular embodiment or of the particular example.
Number | Date | Country | Kind |
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19201455 | Oct 2019 | EP | regional |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2020/077084 | 9/28/2020 | WO |
Publishing Document | Publishing Date | Country | Kind |
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WO2021/063876 | 4/8/2021 | WO | A |
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7823314 | Wheatley | Nov 2010 | B1 |
9383154 | Stone | Jul 2016 | B2 |
10704852 | Michut | Jul 2020 | B2 |
11333460 | Wutte | May 2022 | B2 |
20100281742 | Barrett | Nov 2010 | A1 |
Number | Date | Country |
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102006022622 | Nov 2007 | DE |
1750079 | Feb 2007 | EP |
268996 | Apr 1927 | GB |
1200850 | Aug 1970 | GB |
Entry |
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EP Search Report Intl. Appl. No. PCT/EP2020/077084, dated Dec. 9, 2020. |
Number | Date | Country | |
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20220341695 A1 | Oct 2022 | US |