TRIGGER THAT CAN BE QUICKLY REMOVED FROM AND INSTALLED IN THE LOWER RECEIVER PART OF AR-TYPE WEAPONS

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. § 119 of German Utility Model Application No. 202023002425.0, filed Nov. 21, 2023, the entire disclosure of which is expressly incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a trigger that can be quickly removed from and installed in the lower receiving part of weapons of the AR-type.

2. Discussion of Background Information

Firearms of the type AR-10 or AR-15 are mainly used in the military sector. This type of weapon is also very popular as a sports weapon and in recent years there has been increasing acceptance among hunters. Its development in the 1950s is attributable to Eugen Stoner for the company Armalite. The abbreviation AR originally stood for “Armalite Rifle”.

This type of weapon concerns self-loading rifles, which in their civilian version are designed as semi-automatic weapons and in their military version are sometimes also used as a fully automatic variant. In the case of a semi-automatic weapon, the trigger must be actuated each time for firing. In the fully automatic variant, on the other hand, it is possible to switch to continuous fire.

Today, many manufacturers of this type of weapon no longer designate their weapons as AR-10 or AR-15 but sell their models under their own names. For simplicity, the term “AR-type weapons” will be used from now on.

The designations “left”, “right” and “top”, “bottom” refer to the viewing direction of the shooter with the weapon at the ready. This viewing direction runs along the barrel in the direction of the muzzle.

Almost all AR-type firearms have in common that they are provided with a trigger, which is fitted in the receiver of the weapon by means of two cylindrical pins. For actuation, the trigger has a trigger blade that protrudes downward from the receiver of the weapon. In order to fire a shot, you have to pull the trigger blade with your index finger until a detent between the trigger blade and the hammer is released. Typically, a pre-tensioned double-leg spring causes the hammer to undergo a rotational movement and accelerate until it hits the firing pin.

A distinction is made between triggers without and with their own trigger housing. Triggers with their own trigger housing are also referred to as “drop-in” triggers. For triggers without their own trigger housing, the hammer and the trigger blade are fitted in the receiver of the weapon directly by means of the cylindrical pins.

The receivers of this type of weapon also have in common that the upper receiver part and the lower receiver part are connected to each other by means of two further pins. If the rear of these two pins is pulled out as far as it will go, the upper receiver part can be folded down by way of the front pin, which acts as a hinge, and the trigger is accessible from above. These structural design features have been retained since the 1950s.

In the case of semi-automatic and fully automatic AR-type weapons, some of the gas that propels the projectile through the barrel when fired is diverted to accelerate the bolt of the weapon rearward in the opposite direction of the shot. During this rearward movement, the bolt pushes the trigger hammer down and the trigger is cocked. A compression spring fitted in the buttstock then transports the bolt forward again in the firing direction. A cartridge is at the same time fed from the magazine into the cartridge chamber. After the bolt has locked, the weapon is ready to fire again.

For AR-type weapons which work with a direct gas system, the trigger is particularly quickly and heavily contaminated. This is due to the gases mixed with combustion and powder residues, to which the mechanism of the trigger is directly exposed.

There are also AR-type weapons available which work with an indirect gas system, known as a piston system. In the case of this system, the diverted gas acts on a piston, which in turn accelerates the bolt rearward in the opposite direction of the shot. As a result, significantly less contaminated gas enters the system. However, the trigger mechanism is contaminated with large amounts of contaminated gas because gas flows back into the system after the opening of the bolt and pulling out of the empty cartridge case from the cartridge chamber. This effect is further exacerbated by the use of silencers, which cause a significantly increased backup of gas.

Combustion and powder residues are deposited on the components of the trigger and can cause the moving parts to become sluggish. For this reason, the trigger must be cleaned at regular intervals.

With AR-type weapons, cleaning the trigger is difficult because the mechanical parts are fitted deep in the lower receiver part. This applies to both standard and drop-in triggers. Lubrication or oiling of the moving parts is just as difficult due to the inhibited accessibility.

Maintenance work can be made much easier if the trigger can be removed from the lower receiver part for this purpose. Depending on the type of trigger fitted, disassembly is difficult, because in the vast majority of cases the two pins by means of which the trigger is installed must be removed. Often a hammer and an auxiliary tool in the form of a cylindrical driver are necessary to drive the two pins out of the holes in the lower receiver part. In many cases, the safety must be removed in order to be able to remove the trigger from the lower receiver part. To allow it to be removed, the grip for the trigger hand must first be unscrewed from the lower receiver part. The compression spring and the detent pin, which positions the safety shaft axially, can only be removed when the grip for the trigger hand is in the disassembled state. All of this work will result in parts that can be lost. Not only during disassembly, but also during subsequent assembly, special knowledge is required, for example, in the case of triggers without their own trigger housing, in order to be able to correctly install the trigger parts and their springs back into the lower receiver part and restore their function.

The two cylindrical pins by means of which the trigger is fitted in the lower receiver part of the weapon tend to undergo a rotational movement due to the dynamically acting forces involved in firing. Depending on the design, this rotational movement occurs more or less strongly and can range from a few degrees to half a revolution per shot. The lower receiver parts of AR-type weapons are always produced from relatively soft aluminum alloys. As a result, the rotational movement of the pins and the forces during firing can cause the pin holes in the lower receiver part to enlarge over time and the snug fit between the pins and the holes to be lost. As a result, the trigger becomes loose in the lower receiver part, which affects the precision of the firing. The manufacturers of the weapon receivers try to counteract the wear by applying thin hard anodizing layers, but these hard layers often do not withstand the loads in the long term.

If a standard trigger is installed in a weapon of the AR type as it is used in most military variants but also in the basic configurations of inexpensive sports weapons, this trigger does not have its own housing for cost reasons, so it is not designed as a drop-in trigger. The hammer and the trigger blade are installed in the lower receiver part directly by means of the two pins. In this case, the pins have on their circumference two U-shaped recesses in which spring wires come to lie. Although these spring wires do not prevent the rotational movement of the pins when a shot is fired, they reliably prevent lateral wandering or even loss of the pins. The two U-shaped recesses have proven to be disadvantageous because the pins tend to break at these points.

If more complex drop-in triggers are installed, their trigger housings are in most cases hooked in by means of the two pins in the lower receiver part of the weapon. Since the spring wires which protect the pins from lateral wandering in a standard trigger without its own housing are no longer present in this case, these trigger housings usually have two vertically arranged threaded pins, which support themselves on the bottom of the lower receiver part and push the trigger housing upward, whereby the two cylindrical pins are fixed. It has been shown that the threaded pins tend to become loose due to the dynamic forces when a shot is fired. Therefore, the manufacturers of such triggers usually recommend securing the threaded pins by means of a screw locking in the form of an adhesive, such as for example Loctite®. However, even with adhesively locked screws, the two cylindrical pins in the lower receiver part of the weapon often begin to wander in the axial direction. If such a trigger is to be removed again, the adhesive locking of the threaded pins must first be destroyed again.

There is therefore a need for a trigger for AR-type weapons that can be quickly and easily removed from and reinstalled in the lower receiver part for cleaning and maintenance work. The most effective way of achieving this would be with a trigger which can be removed and installed without having to disassemble any other parts of the weapon, such as for example the safety, the grip for the trigger hand and the two cylindrical pins by means of which the trigger is fitted in the lower receiver part. The work should be able to be carried out without special knowledge being required and without any parts that can be lost occurring.

Moreover, there is the need for a trigger in which the pins for mounting in the lower receiver part cannot twist or wander. In addition, there is the need for a trigger whose mounting pins do not have to have a weakening geometry in the form of U-shaped recesses to prevent them from lateral wandering. There is similarly a need not to have to fix the trigger by means of threaded pins and also with locking adhesive. The trigger must be mounted so stably in the lower receiver part that the shooter does not get a “spongy” feeling when the trigger is actuated, which would adversely affect the shooting precision.

In the prior art, triggers that can be removed from and installed in the receiver of the weapon more quickly and easier than standard triggers are known. Triggers in which the pins for mounting in the lower receiver part do not have the aforementioned disadvantages, or which do not have to be fixed by means of threaded pins and locking adhesive, are also known.

US 2019/0368834 A1 and US 2021/0102770 A1, the entire disclosures of which are incorporated by reference herein, disclose triggers with retractable locking pins suitable for AR-type weapons. Two hollow shafts in which two locking pins are slidably guided are screwed into each of the trigger housings. Each of the locking pins has a drive, which is preferably designed as a hexagon socket, for operation. Moreover, each locking pin is prevented from falling out of the hollow shafts by means of a further pin, which is guided in an L-shaped groove in the hollow shaft. Fitted between the left and right locking pins there is respectively a compression spring, which pushes the locking pins outward. These triggers no longer have pins that can twist or wander in the holes in the lower receiver part of the weapon. However, the force of the springs that push the locking pins outward is far too small to really press them firmly enough against the walls in the pocket and fix them in the holes. Relative movements occur between the hollow shafts, the locking pins and the holes when the trigger blade is actuated, resulting in a “spongy” feeling when the trigger is moved. The dynamic forces caused by the firing of a shot produce much stronger relative movements and thus in the long term an enlargement of the holes in the lower receiver part of the weapon. When removing or installing the trigger, either all four locking pins have to be actuated one after the other with one hex key, or the left and right locking pins of a shaft have to be actuated simultaneously with two hex keys. The texts do not indicate whether the safety must be disassembled to remove or install the trigger.

US 2018/0100712 A1, the entire disclosure of which is incorporated by reference herein, discloses a trigger that can be removed and installed without tools. However, this trigger is not designed for AR-type weapons and their standard lower receiver parts because it cannot be installed there due to the geometry of the trigger housing. The applicant expressly emphasizes this. A safety shaft specially designed for this trigger, which has a groove running in the axial direction and allows disassembly in the “release” position, is required.

US 2021/0222981 A1, the entire disclosure of which is incorporated by reference herein, the entire disclosure of which is incorporated by reference herein, shows a trigger which is installed in the receiver of the weapon by means of pins which have an external thread. The receiver of the weapon has matching internal threads in which the pins are screwed. This trigger is not designed for AR-type weapons because there the holes in the lower part of the receiver are designed as through-holes and do not have internal threads in which pins provided with an external thread could be screwed.

US 2015/0121735 A1, the entire disclosure of which is incorporated by reference herein, proposes a method for fixing a trigger in a lower receiver part in which pins provided with an external thread are screwed into the lower receiver part. This trigger is not designed for AR-type weapons because there the holes in the lower part of the receiver are designed as through-holes and do not have internal threads in which pins provided with an external thread could be screwed. The walls of the lower receiver part shown in the application have been significantly reinforced compared to standard lower receiver parts, so that they could be provided with corresponding internal threads.

US 2016/0341507 A1, the entire disclosure of which is incorporated by reference herein, discloses a method for preventing twisting and wandering of the pins which can be used to fit a trigger in the lower receiver parts of AR-type weapons. To allow standard trigger parts such as hammers and trigger blades to be fitted, the special pins used are provided with the same U-shaped recesses for receiving the spring wires as standard pins, which makes them prone to breaking. It is proposed to prevent the pins from wandering and twisting by locking plates clipped over their ends. This method involves a variety of parts that can be lost occurring during the removal and installation of the trigger.

US 2022/0136792 A1, the entire disclosure of which is incorporated by reference herein, proposes a method for fixing the pins in the lower receiver part of AR-type weapons. The special pins used have an internal thread. Each shaft is secured in the lower receiver part from both sides with the aid of two screws. This method ensures that the pins cannot twist or wander. They also have no weakening recesses on their circumference. However, a variety of parts that can be lost occur when removing and installing the trigger.

US 2011/0167696 A1, the entire disclosure of which is incorporated by reference herein, discloses a method for fixing the trigger housing in the lower receiver part of AR-type weapons. Two threaded pins that are arranged vertically and are accessible from above when the upper receiver part is folded down push the trigger housing off the bottom of the pocket in the lower receiver part. The pushing off has the effect at the same time of preventing the pins by means of which the trigger is mounted in the lower receiver part from twisting and wandering. In practice, such threaded pins tend to become loose even after a short time. Many manufacturers therefore recommend securing the threaded pins with a locking adhesive. If the trigger is to be removed for work involving maintenance and care, the adhesive locking must be destroyed and restored after installation. When removing and installing the trigger, a variety of parts that can be lost occur.

In view of the foregoing, it would be advantageous to have available a trigger that can be quickly removed from and installed in the lower receiver part of AR-type weapons, wherein no further parts of the weapon, such as for example the safety, the grip for the trigger hand and the two cylindrical pins by means of which the trigger is fitted in the lower receiver part, have to be disassembled during the assembly work. The work should be able to be carried out without special knowledge being required and without any parts that can be lost occurring.

It also would be advantageous to have available a trigger in which the pins for mounting in the lower receiver part cannot twist or wander. In addition, its pins should not have to have a weakening geometry in the form of U-shaped recesses.

It further would be advantageous to have available a trigger which can be stably fixed in the lower receiver part and does not have to be fixed by means of threaded pins which in turn have to be secured with locking adhesive.

SUMMARY OF THE INVENTION

A trigger according to the invention that can be quickly installed in and removed from the lower receiver part of AR-type weapons can usually be installed and removed in about 1/4 of the time that has to be spent for a standard trigger.

A trigger according to the invention has a trigger housing, which has two hollow shafts, and wherein a hammer is rotatably mounted on one of the two hollow shafts and a trigger blade is rotatably mounted on the other of the two hollow shafts, and wherein each of the two hollow shafts has a breakthrough, slidably guided in which there is respectively a left bearing journal and a right bearing journal, which are connected to each other by means of a threaded spindle.

In a particularly preferred embodiment of the invention, the hollow shafts in the trigger housing are prevented from twisting by means of a form fit and against falling out by means of a spring wire.

In a particularly preferred embodiment of the invention, the threaded spindles have a section with a right-hand thread and a section with a left-hand thread and are provided on at least one side with a drive for an operating tool, preferably a Torx® drive.

In a further, particularly preferred embodiment of the invention, the bearing journals are prevented from twisting in the hollow shafts by means of a form fit. If the trigger has mounted in the lower receiver part of the weapon, the bearing journals are guided with their cylindrical section in the holes in the lower receiver part of the weapon and support themselves with their bearing surfaces on the inner walls of the pocket.

In a further, particularly preferred embodiment of the invention, the bearing journals can be retracted so far into the hollow shafts that neither the bearing journals nor the threaded spindles protrude beyond the hollow shafts. In this state, the trigger can be removed from or inserted into the lower receiver part.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are described below with reference to the appended drawings. Neither the description nor the drawings are to be understood as a restriction of the scope of the invention.

FIG. 1 shows an AR-type weapon, with a standard trigger installed, according to the prior art, in a perspective representation,

FIG. 2 shows the AR-type weapon, with the upper receiver part folded down, without a trigger installed, in a perspective representation,

FIG. 3 shows a standard trigger pin, according to the prior art, in a perspective representation,

FIG. 4 shows the AR-type weapon, with the upper receiver part folded down, with a standard trigger installed and with the hammer in the released position, according to the prior art, in a perspective representation,

FIG. 5 shows the AR-type weapon, with the upper receiver part folded down, with a standard trigger installed, with the hammer in the released position and an auxiliary tool, according to the prior art, in a view from above,

FIG. 6 shows the AR-type weapon, with the upper receiver part folded down, with a standard trigger installed and with the hammer in the released position, according to the prior art, in half-section, in a view from the left,

FIG. 7 shows a trigger in the assembled state, with the hammer in the released position and with the bearing journals extended, in a perspective representation,

FIG. 8 shows the trigger in an exploded view, with the hammer in the released position and with the bearing journals retracted, in a perspective representation,

FIG. 9 show a subassembly of a trigger shaft, with the bearing journals extended, in a perspective representation,

FIG. 10 shows the subassembly of a trigger shaft, with the bearing journals extended, in half-section,

FIG. 11 shows the subassembly of a trigger shaft, with the bearing journals retracted, in half-section,

FIG. 12 shows the subassembly of a trigger shaft, with the bearing journals extended as far as they will go, in half-section,

FIG. 13 shows the subassembly of a trigger shaft, in an exploded view,

FIG. 14 shows a safety, in a perspective representation,

FIG. 15 shows the AR-type weapon, with the upper receiver part folded down, with a trigger installed, with the hammer in the cocked position and with the safety lever in the “SAFE” position, in half-section, in a view from the left,

FIG. 16 shows the AR-type weapon, with the upper receiver part folded down, with a trigger installed, with the hammer in the released position and with the safety lever in the “SEMI” position, in half-section, in a view from the left,

FIG. 17 shows the AR-type weapon, with the upper receiver part folded down, with the hammer in the cocked state, with the trigger in the first part of the insertion movement into the lower receiver part and with the safety lever in the “SEMI” position, in half-section, in a view from the left,

FIG. 18 shows the AR-type weapon, with the upper receiver part folded down, with the hammer in the cocked state, with the trigger in the second part of the insertion movement into the lower receiver part and with the safety lever in the “SEMI” position, in half-section, in a view from the left.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The particulars shown herein are by way of example and for purposes of illustrative discussion of the embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the present invention. In this regard, no attempt is made to show details of the present invention in more detail than is necessary for the fundamental understanding of the present invention, the description in combination with the drawings making apparent to those of skill in the art how the several forms of the present invention may be embodied in practice.

Elements that are designed exactly the same, but are fitted more than once and in different places, are distinguished from one another below with the aid of a letter index. In the list of reference signs, for example, the standard trigger pin is given by the reference sign 14, and in the explanatory text a distinction is made between the front standard trigger pin 14a and the rear standard trigger pin 14b because they are installed in different places.

FIG. 1 shows a weapon of the type AR 3. The upper receiver part 2 and the lower receiver part 5 are connected by means of the rear receiver pin 1 and the front receiver pin 4. Fitted in the lower receiver part 5 is a standard trigger 6 (see also FIGS. 5 and 6), from which the standard trigger blade 7 protrudes downward from the lower receiver part 5.

In FIG. 2, a weapon of type AR 3 without a trigger installed can be seen. The rear receiver pin 1 has been pulled out as far as it will go and the upper receiver part 2 has been folded down as far as possible from the lower receiver part 5 by way of the front receiver pin 4. Also recognizable are the pocket 8 with its bottom surface 9, its left wall 10 and its right wall 11, as well as the front cross hole 12 and the rear cross hole 13, which completely penetrate the two walls 10 and 11.

FIG. 3 shows a standard trigger pin 14. By means of two of these pins 14a and 14b, standard triggers can be fitted in the lower receiver part 5. Recognizable are the two U-shaped recesses 15 and 16, in which spring wires lie in the installed state, in order to prevent the pin from wandering in the axial direction. The recess 15 is positioned in the middle of the pin and the recess 16 is more to the side, so that in the installed state it is located just next to the inner surface 17 of the left wall 10 or the inner surface 18 of the right wall 11 of the pocket 8 (see also FIG. 5).

FIGS. 4, 5 and 6 show a standard trigger 6, fitted in a weapon of the type AR 3. The standard hammer 19 is in the released position and protrudes approximately vertically upward from the lower receiver part 5. The standard trigger 6 is secured in the lower receiver part 5 by means of the two standard trigger pins 14a and 14b. The front standard trigger pin 14a is inserted in the front cross hole 12 and the standard hammer 19 is rotatably mounted on it. The rear standard trigger pin 14b is inserted in the rear cross hole 13 and the standard trigger blade 7 is rotatably mounted on it. One of the two legs 58 or 59 of the standard hammer spring 20 lies in the recess 16 (see FIG. 3) against the rear standard trigger pin 14b and is intended to prevent the pin from wandering in the axial direction. In a stepped hole 21 in the standard hammer 19 is the spring wire 22, which lies in the recess 15 (see FIG. 3) against the front standard trigger pin 14a and is intended to prevent the pin from wandering in the axial direction. It can be seen that both the front standard trigger pin 14a and the rear standard trigger pin 14b do not have to be mounted in a direction-bound manner because the recess 15 provided in the middle is used on the front pin 14a and the recess 16 provided more to the side is used on the rear pin 14b for positioning the pins in the axial direction. One of the two legs 58 or 59 of the standard hammer spring 20 always lies in the recess 16, irrespective of whether the rear pin 14b has been mounted so that the recess 16 is closer to the inner surface 17 of the left wall 10 or closer to the inner surface 18 of the right wall 11.

FIG. 5 shows an auxiliary tool in the form of a driver 23. By means of such a driver 23 and with the aid of a hammer not shown in FIG. 5, the standard trigger pins 14a and 14b are knocked into the cross holes 12 and 13 or driven out again during disassembly. It is irrelevant from which side of the lower receiver part 5 and in which orientation the pins are mounted.

FIG. 7 shows a trigger 24 according to the invention in the assembled state. It is designed as a drop-in trigger and therefore has its own trigger housing 27. The hammer 25 is in the released position. The trigger blade 26 of the trigger 24 protrudes downward from the trigger housing 27. Also recognizable are the hammer spring 28, the switching shaft 29 and the disconnector 30. The function of the switching shaft 29 and the disconnector 30 is not explained in any more detail at this point because this is irrelevant for the further statements made. The two left bearing journals 31a and 31b as well as the two right bearing journals 32a and 32b have been extended laterally out of the subassemblies of the trigger shafts 33a and 33b by means of a threaded drive explained in more detail in FIGS. 9, 10, 11, 12 and 13. The bearing journals 31a, 31b and 32a, 32b are shown in the position fixed in the lower receiver part 5, in which the bearing shoulders 37 and 38 are lying against the inner surfaces 17 and 18 of the walls 10 and 11. In FIG. 7, the two right bearing journals 32a and 32b with their bearing shoulders 38 cannot be seen because they are covered by the trigger housing 27.

In FIG. 8, the individual parts of the trigger 24 can be seen. The two subassemblies of the trigger shaft 33a and 33b are fitted in the trigger housing 27. The hammer 25 is rotatably mounted on the front subassembly of the trigger shaft 33a, the trigger blade 26 is rotatably mounted on the rear subassembly of the trigger shaft 33b. The hammer 25 has the detent surface 34 and the trigger blade 26 the detent surface 35. The two left bearing journals 31a and 31b as well as the two right bearing journals 32a and 32b have been retracted into the subassemblies of the trigger shafts 33 and therefore do not protrude laterally beyond the trigger housing 27. In this position of the bearing journals 31a, 31b and 32a, 32b, the trigger 24 can be removed from the lower receiver part 5 and reinserted. The hammer spring 28 is designed as a double-leg spring, which supports itself with its legs on the hammer 25 and in the trigger housing 27 and whose coils on the two laterally projecting extensions are guided on the hammer 25.

FIG. 9 shows a subassembly of a trigger shaft 33. The left bearing journal 31 and the right bearing journal 32 have been extended out of the hollow shaft 36 by means of the threaded spindle 39 (see FIGS. 10, 11, 12 and 13) as far as in the state in which it is installed in the lower receiver part 5, in which the left bearing journal 31 is pressed with its bearing shoulder 37 against the inner surface 17 of the left wall 10 and the right bearing journal 32 is pressed with its bearing shoulder 38 against the inner wall 18 of the right wall 11.

The hollow shaft 36 has a cylindrical outer contour over most of its length. In a particularly preferred embodiment, it is provided at its left end with a shoulder 61, the outer shape of which is diamond-shaped. The four corners of the diamond shape are rounded with radii for ease of manufacture and to minimize the notch effect. By means of its diamond shape, the shoulder 61 forms a twist preventer with respect to the trigger housing 27 (see also FIGS. 7 and 8), the wall of which is provided with two holes for the cylindrical part of the outer contour of the hollow shafts 36, and the opposite wall of which is provided with two diamond-shaped breakthroughs for the end of the hollow shafts 36, which have the shoulder 61. In other embodiments of the invention, the twist preventer of the hollow shafts 36 with respect to the trigger housing 27 may also be formed by any other type of form fit. In further embodiments of the invention, the right end of the hollow shaft 36 has the shoulder 61. Accordingly, the two holes are positioned in the left wall and the two diamond-shaped breakthroughs are positioned in the right wall of the trigger housing 27. The subassembly of the trigger shaft 33 in the trigger housing 27 must then be mounted from the left side. The shoulder is provided with at least one V-shaped groove 60, into which the safety wire 44 engages and secures the subassembly of the trigger shaft 33 in the trigger housing 27 in the axial direction (see also FIG. 8). Other embodiments of the groove, such as for example a U-shaped or a rectangular groove, are also conceivable. The threaded pin 45 prevents the safety wire 44 from falling out of the trigger housing 27 (see FIG. 8).

FIG. 10 likewise shows a subassembly of a trigger shaft 33, whose bearing journals 31 and 32 have been extended as far as in the state in which it is installed in the lower receiver part 5. The threaded spindle 39 is provided at its one end with a drive for an operating tool. In this particularly preferred embodiment of the invention the drive is designed as a Torx® drive 43. In the installed state, this drive lies on the right side of the weapon, so that the bearing journals 31 and 32 are extended by an operating action in a clockwise direction and are retracted by an operating action in a counterclockwise direction. This function is achieved by the fact that the threaded section on the threaded spindle 39 on the drive side is designed as a right threaded section 41 and the opposite threaded section is designed as a left threaded section 40. Arranged between the two threaded sections is an undercut 42.

The left bearing journal 31 has an internal thread 46, which is designed as a left-hand thread. The right bearing journal 32 has an internal thread 47, which is designed as a right-hand thread. Both bearing journals have over the greatest part of their length a diamond-shaped outer contour, which serves as a twist preventer in the likewise diamond-shaped breakthrough 62 of the hollow shafts 36 and is formed analogous to the twist preventer of the hollow shafts 36 with respect to the trigger housing 27 (see also FIGS. 9 and 13). The twist preventer of the bearing journals 31 and 32 with respect to the hollow shafts 36 does not have to be formed as a diamond shape but may be formed by any other type of form fit. The locking pin 48 is inserted in a hole 49 in the hollow shaft 36 running transversely to the axis D (see also FIGS. 9 and 13).

Shown in FIG. 11 is the state of the subassembly of the trigger shaft 33 in which the bearing journals 31 and 32 have been retracted into the hollow shaft 36 until they bear against the locking pin 48. In this state, the trigger 24 can be removed from and reinserted into the lower receiver part 5 for removal or installation because the length of the hollow shafts 36 approximately corresponds to the width of the trigger housing 27 and the two ends of the hollow shafts 36 in the mounted state finish approximately flush with the left and right outer walls of the trigger housing 27 (see also FIG. 8).

In order to prevent that, in the state in which the trigger 24 has been removed from the lower receiver part 5, the user turns the threaded spindle 39 counterclockwise to such an extent that the bearing journals 31 and 32 come away from the threaded spindle 39 and fall out of the hollow shaft 36, the threaded spindle 39 is provided at its end opposite from the Torx® drive 43 with a countersink 50 that can be seen in FIG. 12. When installing the trigger 24 at the factory, the countersink 50 is compressed with a special tool in such a way that the first thread is deformed and the left bearing journal 31 cannot be unscrewed from the threaded spindle 39 without considerable effort. By guiding the two bearing journals 31 and 32 in the hollow shaft 36 and their synchronized, opposite movement in the axial direction when turning the threaded spindle 39, this measure has the effect that the right bearing journal 32 also cannot be unscrewed from the threaded spindle 39 without considerable effort.

The subassembly of the trigger shaft 33 shown in FIG. 12 shows the state in which the deformed, first thread of the threaded spindle 39 blocks the internal thread 46 of the left bearing journal 31 because it represents a stop with respect to the left bearing journal 31. This state can only be achieved in the state in which it has been removed from the lower receiver part 5, because in the installed state the bearing shoulders 37 and 38 of the bearing journals 31 and 32 already come to bear against the inner surfaces 17 and 18 of the walls 10 and 11 beforehand.

The hole 49 (see FIGS. 9 and 13) for the locking pin 48 is positioned in the hollow shaft 36 in such a way that, in the state shown in FIG. 12, neither of the two bearing journals 31 or 32 can fall out of the hollow shaft 36 because the other bearing journal respectively is previously blocked by the locking pin 48.

In FIG. 13, the individual parts of the subassembly of the trigger shaft 33 can be seen again. The hole 49 in the hollow shaft 36 is positioned such that the locking pin 48 cannot fall out because the hole is covered by the hammer 25 or by the trigger blade 26 (see also FIGS. 7 and 8). Thus, the locking pin 48 does not have to be secured in the axial direction by for example adhesive locking, caulking, pressing or shrinking (see also FIGS. 15 and 16).

Shown by way of example in FIGS. 1, 2, 4 and 5 is a weapon of the type AR 3, in which the safety lever 52 of the safety 51 has three possible positions engraved on the lower receiver part 5:

• • SAFE (secure)
  • SEMI (semi-automatic firing)
  • AUTO (fully automatic firing)

The safety 51 shown in FIG. 14 is, in this embodiment given by way of example, a component cast from one piece consisting of the safety lever 52 and the safety shaft 53. Also available on the market are multipart safeties, in which the safety lever is secured to the safety shaft for example by means of screws or pins. Also known are safeties that can be operated on both sides, which have a safety lever at both ends of the safety shaft. Recognizable is the circumferential surface 54, which in the “SAFE” position blocks the trigger blade 26, and the flat 55, which in the “SEMI” position allows a triggering movement of the trigger blade 26. The “AUTO” position is not explained in any more detail at this point because this is irrelevant for the further statements made.

FIGS. 15 and 16 explain the interplay between the safety shaft 53 and the trigger blade 26 in more detail.

In FIG. 15, the hammer 25 is in the cocked state and the safety lever 52 (cannot be seen due to the sectional representation in FIG. 15) is in the “SAFE” position. The hammer 25 lies with its detent surface 34 against the detent surface 35 on the trigger blade 26. The safety shaft 53 blocks with its circumferential surface 54 the trigger blade 26. The rear end of the trigger blade protrudes only as far as is strictly necessary to the rear beyond the vertical axis V, which passes through the point of rotation of the safety shaft 53. The insertion slope 56 can be recognized. A gap between the underside of the trigger housing 27 and the bottom surface 9 can likewise be seen. The trigger 24 is thus not located in the lower receiver part 5 but is held exclusively by the subassemblies of the trigger shafts 33.

In FIG. 16, the hammer 25 is in the released state, the locking lever 52 in the “SEMI” position and the safety shaft 53 allows a triggering movement of the trigger blade 26 by its flat 55. When the trigger blade 26 is actuated, the detent surfaces 34 and 35 are released and the hammer spring 28 accelerates the hammer 25 until it hits the firing pin, not shown, which is located in the upper receiver part 2.

FIG. 17 shows that, when installing, the trigger 24 must be held up at an angle to the front so that the trigger blade 26 moves past the safety shaft 53 and it can at the same time be threaded through the hole 57 in the lower receiver part 5.

It can be seen from FIG. 18 that the insertion slope 56 in conjunction with the rear end of the trigger blade 26, which is kept as short as possible, allows the trigger blade 26 to be inserted with its rear end between the safety shaft 53 and the bottom surface 9. The trigger 24 can be inserted most easily in the “SEMI” position of the safety lever 52, in which the flat 55 of the safety shaft 53 is in the horizontal position.

It can be seen from FIGS. 17 and 18 that, in order to remove or install a trigger 24 according to the invention, the safety 51 and the grip for the trigger hand do not have to be disassembled.

The removal or installation of a trigger 24 according to the invention from or into the lower receiver part 5 of a weapon of the type AR 3 is described below.

Removing the trigger:

• • 1. Pull out the rear receiver pin 1 as far as it will go and fold down the upper receiver part 2 from the lower receiver part 5.
  • 2. If the hammer 25 is in the released position, it must be moved into the cocked position.
  • 3. By means of a suitable Torx® key, retract the bearing journals 31 and 32 of both subassemblies of the trigger shaft 33 into the hollow shafts 36 by turning to the left until they bear against the locking pins 48.
  • 4. Remove the trigger 24 from the lower receiver part 5.

Installing the trigger:

• • 1. If the hammer 25 is in the released position after maintenance or cleaning work, it must be moved into the cocked position.
  • 2. Hold the trigger 24 up at an angle to the front and, when inserting it into the lower receiver part 5, first thread the trigger blade 26 through the breakthrough 57 and then at the same time guide it with its rear end past the safety shaft 53.
  • 3. Guide the rear end of the trigger blade 26 rearward between the flat 55 on the safety shaft 52 and the bottom surface 9 until the trigger housing 27 can be placed on the bottom surface 9.
  • 4. By means of a suitable Torx® key, extend the bearing journals 31 and 32 of both subassemblies of the trigger shafts 33 out of the hollow shafts 36 by turning to the right, until they have centered themselves in the cross holes 12 and 13 and lie with their bearing shoulders 37 and 38 against the inner surfaces 17 and 18 of the walls 10 and 11. A gap is thereby formed between the underside of the trigger housing 27 and the bottom surface 9.
  • 5. Tighten both threaded drives securely.
  • 6. Fold the upper receiver part 2 back onto the lower receiver part 5 and push the rear receiver pin 1 in as far as it will go.

In a further embodiment of the invention that is not shown, the threaded spindle 39 is provided with a drive at both ends. In this embodiment, the operator can handle the weapon from both sides.

In order to deform the last thread and thus create a stop for the left bearing journal 31, the threaded spindle 39 does not necessarily have to be provided with a countersink 50. This can also be implemented if the end concerned is provided with a drive, such as for example a hexagon-socket or Torx® drive.

In further embodiments of the invention that are not shown the threaded spindle 39 is provided at its left end with a drive. The operator must then handle the weapon from the left side.

Also possible is an embodiment in which the right threaded section of the threaded spindle 39 is designed as a left-hand thread and the left threaded section is designed as a right-hand thread. The internal threads of the bearing journals must then be designed accordingly.

In further embodiments of the invention that are not shown, the drive of the threaded spindle 39 may also be designed as a slot, cross slot, hexagon socket or any other drive form.

In a further embodiment of the invention that is not shown, the threaded connection between the threaded spindle 39 and at least one of the bearing journals 31 or 32 is provided with a thread lock. This thread lock may be designed for example as a threaded wire insert, as a chemical thread lock in the form of a spot coating or any other kind.

In a further embodiment of the invention that is not shown, the rear end of the trigger blade 26 does not have an insertion slope 56, but has any other contour which, when the safety 51 has been installed, allows the trigger blade 26 to be guided through the breakthrough 57 and the rear end of the trigger blade 26 to be inserted between the safety shaft 53 and the bottom surface 9 when inserting the trigger 24 into the pocket 8 in the lower receiver part 5.

LIST OF REFERENCE SIGNS

• • 1 Rear receiver pin
  • 2 Upper receiver part
  • 3 AR-type weapon
  • 4 Front receiver pin
  • 5 Lower receiver part
  • 6 Standard trigger
  • 7 Trigger blade of the standard trigger 6
  • 8 Pocket
  • 9 Bottom surface
  • 10 Left wall
  • 11 Right wall
  • 12 Front cross hole
  • 13 Rear cross hole
  • 14 Standard trigger pin
  • 15 Recess positioned in the middle
  • 16 Recess positioned to the side
  • 17 Inner surface of the left wall 10
  • 18 Inner surface of the right wall 11
  • 19 Standard hammer
  • 20 Standard hammer spring
  • 21 Stepped hole for spring wire in the standard hammer 19
  • 22 Spring wire in the standard hammer 19
  • 23 Driver
  • 24 Trigger
  • 25 Hammer
  • 26 Trigger blade
  • 27 Trigger housing
  • 28 Hammer spring
  • 29 Switching shaft
  • 30 Disconnector
  • 31 Left bearing journal
  • 32 Right bearing journal
  • 33 Subassembly of the trigger shaft
  • 34 Detent surface on the hammer 25
  • 35 Detent surface on the trigger blade 26
  • 36 Hollow shaft
  • 37 Bearing shoulder on the left bearing journal 31
  • 38 Bearing shoulder on the right bearing journal 32
  • 39 Threaded spindle
  • 40 Left threaded section
  • 41 Right threaded section
  • 42 Undercut
  • 43 Torx® drive
  • 44 Safety wire
  • 45 Threaded pin
  • 46 Internal thread designed as a left-hand thread
  • 47 Internal thread designed as a right-hand thread
  • 48 Locking pin
  • 49 Hole for locking pin 48
  • 50 Countersink
  • 51 Safety
  • 52 Safety lever
  • 53 Safety shaft
  • 54 Circumferential surface
  • 55 Flat
  • 56 Insertion slope
  • 57 Breakthrough in the lower receiver part 5
  • 58 First leg of the standard hammer spring 20
  • 59 Second leg of the standard hammer spring 20
  • 60 Groove
  • 61 Shoulder
  • 62 Breakthrough in the hollow shaft 36