EP3835708A1 - Front shaft for clamping on a weapon in front - Google Patents

Abstract

The invention relates to a fore-end for clamping assembly on an existing firearm with a shaft axis (41), in particular on its running nut (13), comprising: a shaft housing (11) which has a slot (17) radially to the shaft axis (41) and with a Clamping device (2), comprising a lever (21) with a center piece (26) which encompasses the lever axis (291) and which lies in a through-opening of the shaft housing (11) in a plane normal to the shaft axis (41), and which has a Recess (23), a thread (24) at one end and a lever arm (27) at the other end, and a nut (3) with an internal thread matching the thread (24); The invention is characterized in that the middle piece (26) is provided at its end region directed towards the lever arm (27) with a clamping cone (22) which widens towards the lever arm (27); and that in the assembled state the nut (3) is screwed onto the thread (24) and thus narrows the slot (17) and the angular position of the lever (21) around its lever axis (291) is such that the center piece (26) in an annular groove (131) of the traveling nut (13) is arranged contacting.

Description

The invention relates to a fore-end for clamping assembly on a firearm, in particular a rifle (carbine), also called fore-end clamping or just clamping, specifically for weapons of the rifle type M4 / M16 / AR15, according to the preamble of claim 1. The clamping device according to the invention and their variants are not limited to rifles, carbines, etc., but can in principle also be used for pistols. The improvements and their effects / benefits are listed below.

In numerous rifles (carbines), in particular those of the types mentioned, fore-ends have been known for many years as independent parts and are commercially available that meet a wide variety of requirements. It is therefore assumed in the following and in the claims of the carbine as existing, the invention relates to a fore-end that is adapted to this and which thus fits the weapon geometrically and functionally so that it can be used with the fore-end according to the invention. The following can be briefly stated as a general technological background:
On the one hand, fore-ends form a grip area for the free hand - the target hand - of the shooter and serve as protection against burns on the hot barrel. On the other hand, a forend protects the barrel from knocks, dirt, etc. and can be used as a mount for a variety of accessories, such as riflescopes, residual light amplifiers, flashlights, laser pointers, and much more.

The fore-end can be understood as a kind of extension of the housing of a rifle in the direction of travel. In order to improve the precision of a rifle, the fore-end must therefore be connected to the housing as rigidly as possible relative to the barrel and therefore also relative to the housing. However, the barrel must be able to swing "freely" when the shot is fired.

The barrel is usually attached to the housing by means of a barrel nut, which is usually designed as a union nut and screwed to the housing. The traveling nut presses the barrel against a radially projecting shoulder of the housing.

A multitude of possibilities for coupling a fore-end to the housing are known from the prior art for rifles of the type AR-15, whereby very often a clamping in the circumferential direction, i.e. tangential to the shaft axis nothing else results, even if the term "axial direction" is used, the reference axis is made. In most cases, tensioning against the running direction, that is to say against the upper housing, is implemented by means of a separate, second, clamping device.

There remains the desire to quickly dismantle / assemble the fore-end, whether in use or for maintenance purposes. Furthermore, the dismantling or assembly process should be able to be carried out as simply as possible. Special tools are often required, which of course have to be carried separately. Often the tangential clamping takes place via screws, which clamp the fore-end tangentially to the traveling nut, as shown in the example US 9,032,658 B2 shown. There is an additional safeguard against displacement of the fore-end in the axial direction by partially engaging the screws in grooves provided for this purpose in the traveling nut.

The US 7,5228,580 B1 which prevents the fore-end from being displaced in the axial direction by means of a tangentially displaceable locking pin.

As a rule, a plurality of components is required in order to form a clamp at least in the tangential direction. Securing and pre-tensioning the barrel in the axial direction, preferably also by means of a clamp, would also be desirable in order to form the most rigid possible connection between the housing and the fore-end.

The object of the present invention is therefore to provide a clamping device which ensures that the fore-end is secured against displacement relative to the housing and at the same time ensures a rigid connection to the housing. Another object of the invention is that the smallest possible number of components is used for the clamping device. A further object of the invention is to provide a clamping device which is easy to handle, easy to maintain and has a relatively simple structure.

This object is achieved by the features specified in the characterizing part of claim 1. In other words, form

In the description and claims, "in front of" or "forwards" as the direction towards the muzzle of the barrel, "(towards) rear" as the direction towards the shaft, "(down)" as the direction for the breech towards the magazine, and "(up)" used as the direction away from the magazine. The terms "weapon center plane", "barrel core", "barrel axis", "core axis", etc. have the usual meanings which the person skilled in the art attaches to them in the prior art. "Left" is therefore related to the weapon center plane, "from the left" corresponds to a movement, actuation, exertion of force in the direction of the weapon center plane, starting from a starting position "to the left" of it, etc .. The closure is made under the action of the gases the firing of a shot moves "backwards" and comes back "forwards" under the action of a closing spring, etc ..

• die Fig. 1 eine schematische Explosionsdarstellung eines Vorderschafts,
• die Fig. 2 den Schnitt II-II der Fig. 1,
• die Figs. 3a,b den Schnitt III-III der Fig. 1 in zwei unterschiedlichen Klemmsituationen,
• die Figs. 4a,b einen Hebel in zwei unterschiedlichen perspektivischen Ansichten,
• die Figs. 5a-c eine Mutter in unterschiedlichen Ansichten,
• die Figs. 6a,b ein Detail am Vorderschaft in unterschiedlichen Ansichten und
• die Figs. 7a-c unterschiedliche Klemmsituationen in einem axialen Schnitt.

The invention is explained in more detail below with reference to the drawings. It shows or shows:

• the Fig. 1 a schematic exploded view of a fore-end,
• the Fig. 2 the section II-II of the Fig. 1 ,
• the Figs. 3a, b the section III-III of the Fig. 1 in two different jamming situations,
• the Figs. 4a, b a lever in two different perspective views,
• the Figs. 5a-c a mother in different perspectives,
• the Figs. 6a, b a detail on the forend in different views and
• the Figs. 7a-c different clamping situations in one axial section.

In the figures, as far as possible everything that relates to the fore-end 1 without the clamping device has been designated with "1n", analogously to this, if possible, everything that relates to the clamping device 2 is designated with "2n".

In the Figs. 1-6 Exemplary embodiments are shown which are suitable for use in a rifle of the AR15 or M4 type. Modifications of the examples shown can easily, simply and without extensive or complex experiments be transferred to other types of rifles by the person skilled in the art with knowledge of the invention.

The Fig. 1 shows a schematic exploded view of a fore-end 1 with housing 11 and built-in spacer 12, which is not essential to the invention and is therefore not explained further. Also shown is a clamping device 2 according to the invention with a lever 21, a nut 28 and a locking ring 281; a coordinate system 51 used variously in the description and the claims - running direction, shaft direction, forward; 52-transverse direction to the left and 53-vertical direction up are entered for better orientation.

The Fig. 2 shows the section II-II of Fig. 1 , an axial section through the shaft axis 41, thus parallel to the barrel axis. The barrel 15 lies radially closest to the barrel axis (parallel to or coinciding with the shaft axis 41); a barrel nut 13 in the form of an elongated sleeve may be pushed onto it and connected to the upper housing 14 at its rear end by means of a screw connection 42. A collar of the barrel 15 is thus pressed by a rear end face of the running nut 13 against a front end face of the upper housing 14 and the barrel 15 itself is held in this way. The housing 11 of the fore-end 1 encloses not only the barrel 15 including barrel nut 13, but also a gas pipe 16.

An annular groove 131 is provided in the traveling nut 13; the lever 21 lies partly in this annular groove, and in this illustration it is cut in the area of its central piece 26. In the housing 11 there is an elongated hole extending in the transverse direction 52 provided, the cross-section of which has circular end sections, two parallel slot axes 191, 192 running in the transverse direction 52. These axes lie in a plane normal to the vertical 52.

The Figs. 3a , b are a section along the line III-III of Fig. 1 , thus normal to the shaft axis 41, and represent two different clamping situations.

The structure itself is as follows: The threaded end of the lever 21 is pushed through the elongated hole 19, the nut 28 with its cone 282 is directed towards the weapon, screwed on and secured against loss by means of the resilient locking ring 281. By screwing on the nut 28, a longitudinal slot 17 of the housing 11 or of the spacer 12 is changed in its width in the area of the lever 21 and, with the conical sections 22 of the shaft and 282 of the nut, ensures pretensioning and adjustment.

• der Ringnut 131 der Laufmutter 13,
• des Langloches 19 des Gehäuses 11 und
• des Schaftes des Hebels 21

das Gehäuse 11 in Richtung 51 der Schaftachse 41 zum Obergehäuse 14 hin gezogen und durch das (vorherige oder weitere) Anziehen der Mutter 28 mit verengendem Schlitz 17 eine zunehmende Klemmung in Umfangsrichtung - also tangential zum Lauf 15 - bewirkt.The Fig. 3a shows the released position in which the recess 23 is directed towards the shaft axis 41 and allows a longitudinal movement of the housing 11 along the barrel and the traveling nut 128 (if the nut 28 is not screwed on too tightly), since the contour in the area of the recess 228 lies radially outside the contour of the traveling nut. If the rear end position ( Fig. 2 ) is reached, the lever arm 27 is rotated by 180 ° around the lever axis 291, if necessary after the nut 28 has been tightened, whereby the shaft with its non-tapered surface area reaches the annular groove 1281. The positions and geometries:

• the annular groove 131 of the traveling nut 13,
• the elongated hole 19 of the housing 11 and
• of the shaft of the lever 21

the housing 11 is drawn in the direction 51 of the shaft axis 41 towards the upper housing 14 and by tightening the nut 28 (previously or further) with the narrowing slot 17, increasing clamping in the circumferential direction - i.e. tangential to the barrel 15 - is achieved.

The ones in the Figs. 4a , b The clamping device 2 shown in detail consists of a lever 21 with a shaft with a lever axis 291, in one end region of which a thread 24 is provided, and at the other end of which a lever arm 27 protrudes approximately at right angles. In this end area, the diameter of the shaft increases conically to the lever arm 27 and forms a clamping cone 22. The shaft has a recess 23 on the center piece 26, approximately in the center, which forms a generally cylindrical, preferably circular cylindrical, lateral surface; in the exemplary embodiment, the generators of the lateral surface run parallel to the plane defined by the lever axis and the lever arm 27. It can also be seen from these figures that the thread 24 does not extend to the end of the shaft, but rather ends at an annular groove 25, the inner diameter of which is smaller than the diameter of the thread root. The shaft diameter in the direct end area is larger than that of the groove, but smaller than that of the thread root.

With the thread 24 of the shaft, a nut 28 cooperates, which in the Figs. 5a -c is shown. This nut 28 is provided in a first axial area with an internal thread which can interact with the thread 24, in a second axial area it has a cylindrical bore (recess) with a larger diameter than the shaft diameter. This recess leads over the entire remaining length (actually height) of the nut 28. In the first axial area, the outer contour of the nut is cylindrical with a subsequent conical taper towards the end; in the second, an external hexagon is provided.

By rotating the lever arm 27 in the installation position (see Figs. 3 and 7th ) is secured against axial displacement by the center piece 26 in cooperation with the annular groove 131 of the fore-end 1. A special feature is the design of the clamping cone 22 on the shaft of the lever 21 and the clamping cone 282 on the nut 28 in connection with the two corresponding clamping surfaces 18 of the fore-end 1.This double-conical configuration results in a self-centering clamping when the nut 28 is tightened after moving lever 2 into the locked position.

An aspect of the invention that is also important in one embodiment lies in the design of the in the Figs. 6a , b elongated hole 19, shown in more detail, which, as already mentioned, has two elongated hole axes 191, 192 running parallel to one another. In addition, there is the, preferably concentric, conical, clamping surface 18 (on both sides of the fore-end 1), which is centered around the axis 191 and results in a displacement and / or force being applied to the fore-end counter to the running direction when a tangential force is applied around the lever axis 291 , to the upper housing 14, takes place, which enables an axial fixation and thus fixation in addition to the tangential fixation.

The assembly takes place with the lever 21 in the "OPEN" position up to the stop on the "upper", then the nut 28 is tightened, narrows the gap 17 and thus fixes the housing 5 to the traveling nut 128. This situation is essentially in Figs.7a -c shown. The first elongated hole axis 191 is further away from the upper housing 14 than the second elongated hole axis 192.

In Figure 7a If the housing 11 with the clamping device 2 is placed in the "OPEN" position, the lever axis 291 is at a distance from the second elongated hole axis 192 and is closer to the upper housing than this.

The Figure 7b shows the situation when the lever 21 is rotated into the "LOCKED" position, the two axes have come much closer to each other and can also coincide.

The Figure 7c shows the situation after the clamping nut 28 has been tightened, since the clamping surface 18, which is conical around the axis 191, as the arrow indicates, loads / shifts the housing 11 of the fore-end 1 in the direction of the upper housing 14, so that stable mechanical conditions prevail .

Thus, the invention enables tangential and axial clamping of the fore-end at the same time.

In the exemplary embodiment shown, the outer diameter of the nut 28 is selected so that part of the weapon, preferably the slide (not shown), can be used to loosen the nut 28. This means that the slider 28 with its slot-shaped opening, which allows the hammer or striking piece to pass through, can be used to unscrew the nut 28. Thus, a "half-inch" width of the nut head is particularly preferred.

Further refinements relate to the already explained loss protection of the clamping device by means of the annular groove 25 on the lever 21 in conjunction with the locking ring 281, which prevents the nut from being completely unscrewed and thus prevented from being lost.

It is clear to the person skilled in the art that the illustrated and described embodiments are to be regarded as exemplary; with knowledge of the invention, he can easily transfer and adapt it to other weapons. The materials to be used are the same as in the prior art, as are the processing and the manufacturing methods to be selected.

In the description and the claims, the terms "front", "rear", "top", "bottom" and so on are used in their usual form and with reference to the object in its usual position of use. This means that in a weapon the muzzle of the barrel is "front", that the breech or slide is moved "back" by the explosion gases, etc .. Transverse to a direction essentially means a direction rotated by 90 °, Unless otherwise indicated, the variously drawn and described coordinate system 51 - running direction, 52 - transverse direction and 53 - vertical (when the weapon is normally held at the ready) is specifically pointed out for better orientation.

It should also be pointed out that in the description and the claims, statements such as "lower area" of an object mean the lower half and in particular the lower quarter of the total height, and "lowest area" means the lowest quarter and in particular an even smaller part; while "middle area" means the middle third of the total height (width - length). All of this information has its common meaning, applied to the intended position of the object in question, unless otherwise stated.

In the description and the claims, "essentially" means a deviation of up to 10% of the specified value, if it is physically possible, both downwards and upwards, otherwise only in the meaningful direction, for degrees (angle and temperature) this means ± 10 °.

All quantities and proportions, in particular those to delimit the invention, unless they relate to the specific examples, are to be understood with a tolerance of ± 10%, thus for example: 11% means: from 9.9% to 12.1%. In terms such as: "a solvent", the word "a" is not to be seen as a numerical word, but as an indefinite article or as a pronoun, unless the context indicates otherwise.

Unless otherwise stated, the term: “combination” or “combinations” stands for all types of combinations, starting from two of the constituents in question up to a large number or all of such constituents, the term: “containing” also stands for “consisting out".

The features and variants specified in the individual configurations and examples can be freely combined with those of the other examples and configurations and used in particular to characterize the invention in the claims without necessarily including the other details of the respective configuration or the respective example

To make the invention easier to understand, the English terms, which can also be used as synonyms, are given in the following list of reference symbols. 1 Fore-end (forestock) 41 Stock axis 11 Fore-end housing (handguard) 42 Screw connection 12th Spacer 13th Barrel nut 51 Barrel direction 131 Barrel nut channel 52 Transverse direction (normal direction) 14th Upper receiver 53 Vertical direction 15th Barrel 16 Gas pipe 17th Slit 18th Clamp taper surface 19th Long hole 191 First long hole axis 192 second long hole axis 2 Clamping device 21 Lever 22nd Clamp taper socket 23 Recess 24 Thread 25th Ring recess 26th Center element 27 Lever arm 291 Lever axis 28 Nut 281 Safety ring 282 Clamp taper socket

Claims (4)

Forend for clamping assembly on an existing firearm, in particular on its barrel (15) or its barrel nut (13), the barrel (15) or barrel nut (13) having an annular groove (281), comprising: - A shaft housing (11) with a shaft axis (41) which has a slot (17) running radially to it and a through opening for the clamping device running in the transverse direction (52), - A clamping device (2) for the shaft housing (11), having ∘ a lever (21) with a center piece (26) which encompasses the lever axis (291) and which lies in a through-opening of the shaft housing (11) in a plane normal to the shaft axis (41), and which has a recess (23) in its central region, has a thread (24) at one end region and a lever arm (27) at the other end, and ∘ a nut (28) with an internal thread matching the thread (24); characterized in that the middle piece (26) is provided at its end region directed towards the lever arm (27) with a clamping cone (22) widening towards the lever arm (27) and makes contact with a conical clamping surface (18) of the shaft housing (11); that in the assembled state the nut (28) is screwed onto the thread (24) and thus narrows the slot (17), and that the angular position of the lever (21) around its lever axis (291) is such that its center piece (26) the annular groove (281) contacted. Forearm according to claim 1, characterized in that the middle piece (26) is provided with an annular groove (25) at its end region having the thread (24), and that the nut (28) has the internal thread in a first axial section and on the The outside is provided with a conical section, a clamping cone (32), that a bore with a larger diameter is formed in a second axial section, and that a locking ring (31) is inserted into the annular groove (25). Forearm according to claim 1 or 2, characterized in that in the stock housing (11) the through opening for receiving the center piece (26) has an elongated hole (19) with an outline consisting of two semicircles with a first Axis (191) and a second axis (192) parallel to it and a rectangle in between. Forearm according to Claim 3, characterized in that the elongated hole (19) has conical clamping surfaces (18) at both ends, which are formed centrally around the first axis (191) and which interact with the clamping cones (22, 32).

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