FIREARM TRIGGER MECHANISM

Description

Title FIREARM TRIGGER MECHANISM INTERNATIONAL PATENTS Ingg. Zini, MaraWstf® C. srl -1 DESCRIPTION of the industrial invention entitled: TRIGGER MECHANISM FOR FIREARMS in the name of BENELLI ARMI SPA with headquarters in URBINO PU DESCRIPTION TEXT The present invention relates to a trigger mechanism for firearms. The trigger mechanism of a firearm generally consists of a hammer rotating around a fulcrum and operated by a spring. The hammer has one end equipped with a sear tooth which engages the trigger stop tooth in such a way that a rotation of the trigger corresponds to the release of the hammer which, activated by the spring, acts on the firing pin. In the firing action, there are two critical moments in the action of the spring on the hammer: the first critical moment is the percussion phase, during which it is preferable for the spring to act with the maximum possible force on the hammer, the second critical moment is the cocking phase of the hammer which naturally must encounter the least resistance possible, especially when dealing with automatic or semi-automatic weapons. In known trigger mechanisms the spring is generally in the position of maximum compression in the cocking phase, while in the percussion phase the spring is in the position of maximum extension, therefore, in a traditional system, the spring exerts excessive resistance in the cocking phase, INTERNATIONAL2 PATENTS Ingg. Zini, Maran4§iW < / s.r.l. -2while, in the percussion phase, not all possible force is exerted on the dog. European patent EP0494439 describes a trigger mechanism comprising a spring-driven hammer that rotates around a fulcrum, defining a cocked position and a firing position. The spring acts directly on the hammer at a point defining a lever arm with the hammer's fulcrum, allowing the lever arm to vary between the cocked and firing positions. The spring has one end located in a conical seat in the body of the firearm, and a second end acting on a point on the hammer; the combination of these contact points defines a particular shape such that the spring tilts from a forward to a rearward position as the hammer moves from the cocked position to the firing position, so that in the firing position, the force exerted by the spring on the hammer has a greater normal component. EP0494439 brilliantly overcomes the problems of the prior art described above by offering a trigger mechanism in which the force exerted by the spring during the percussion phase is increased while the resistance offered during the cocking phase is reduced. This mechanism therefore ensures a limited load on the trigger during the release phase. As is known in a so-called semi-automatic weapon, the repeating trigger mechanism is constructed in such a way as to fire only one bullet for each complete stroke of the trigger, therefore internationallyWevetti -3- Eng. Zini, Marangs / & C. srl the weapon is limited to firing a single shot with each pull of the trigger, unlike an automatic weapon in which the repeating trigger mechanism is designed to be able to fire all available cartridges with a single pull of the trigger. A semi-automatic shotgun equipped with an inertial recovery system, of the type produced by this same applicant, is one of the fastest, if not the fastest, smoothbore semi-automatic shotguns and is capable of completing the firing cycle in less than 200 ms. With such a cycling speed it is very difficult to apply multiple pressures on the trigger in a shorter time, however there are shooters skilled enough to be able to do it. This causes the hammer to fail to engage the trigger assembly if the user repeats the shot at such a speed that the striker misses and therefore cannot fire the next shot. The aim of the present invention is to provide a trigger mechanism that is improved with respect to the prior art cited. Within the scope of this task, a particular aim of the invention is to provide a trigger mechanism for semi-automatic weapons capable of always ensuring firing regardless of the speed at which the trigger is actuated by the user. Another object of the present invention is to provide INTERNATIONAL! Ingg. Zini, Maran a trigger mechanism that, thanks to its unique manufacturing features, is able to ensure the widest guarantees of reliability and safety in use. These purposes and others which will become clearer later on are achieved by a trigger mechanism as claimed in the attached claims. Further features and advantages will become more apparent from the description of preferred, but not exclusive, embodiments of the invention, illustrated by way of example and not by way of limitation in the attached drawings, in which: Figure 1 is a perspective view of a bolt guard assembly comprising the trigger mechanism for firearms, according to the invention; Figure 2 is a partially exploded perspective view of the mechanism; figure 3 is a side view, along the section plane III-III of figure 6, illustrating the mechanism in the sear tooth position; figure 4 is an enlarged view of a detail of the previous figure; Figure 5 is a side view showing the mechanism in the sear engaged position; Figure 6 is a plan view illustrating the mechanism in the sear tooth engaged position; Figure 7 is a side view, along the section plane INTERNATIONAL' Eng. Zini, Marar^ IX-IX of figure 10, illustrating the mechanism in the safety catch tooth position engaged; Figure 8 is an enlarged view of a detail of the previous figure; Figure 9 is a side view illustrating the mechanism in the engaged safety catch position; Figure 10 is a plan view illustrating the mechanism in the engaged safety catch position; figure 11 is a front view, according to the section plane XI-XI of figure 9; figure 12 is a side view, along the section plane XII-XII of figure 16, illustrating the mechanism in the fast firing position with the bolt open; Figure 13 is an enlarged view of a detail of the previous figure; Figure 14 is an enlarged view of another detail of Figure 12; Figure 15 is a side view showing the mechanism in the fast-fire position with the bolt open; Figure 16 is a plan view illustrating the mechanism in the fast-fire position with the bolt open; figure 17 is a side view, along the section plane XVII-XVII of figure 20, illustrating the mechanism in the fast firing position with the bolt close to closing; Figure 18 is an enlarged view of a detail of the figure INTERNATIONAPÉÀBJEVETTI _g_ Eng. Zini, Mararleéi· / C. srl previous; Figure 19 is a side view illustrating the mechanism in the fast firing position with the bolt close to closing; Figure 20 is a plan view illustrating the mechanism in the fast firing position with the bolt close to closing; figure 21 is a side view, along the section plane XXI-XXI of figure 24, illustrating the mechanism in the fast firing position during the completed closure; Figure 22 is an enlarged view of a detail of the previous figure; Figure 23 is a side view illustrating the mechanism in the fast firing position during the completed closure; Figure 24 is a plan view illustrating the mechanism in the fast firing position during the completed closure; figure 25 schematically illustrates the condition of the hammer resting on the closed bolt; Figure 26 is a side sectional view illustrating the hammer resting on the closed bolt. With reference to the figures cited, the trigger mechanism according to the invention, indicated globally with the reference number 1, comprises a trigger 11 pivoted to the structure 20 of a guard by means of a trigger pin 13 and equipped with a stop or trigger tooth 9. internationalWevetti Ingg. Zini, MaranWA C. s.rl. -ΊThe mechanism comprises a hammer 3 pivoted on the trigger guard 20 and loaded by an elastic element, i.e. a trigger spring 23, until it strikes a firing pin present on a bolt 8, in a manner known per se. The hammer 3 is equipped with a first tooth 77 suitable for engaging the sear tooth 9 of the trigger 11. The trigger 11 has a safety catch tooth 2 which engages a second tooth 17 of the hammer 3. The safety catch 2 is hinged to the trigger 11 and is capable of a slight rearward movement in opposition to an elastic element 19. The trigger mechanism is equipped with a safety device 21, which is known in itself and not illustrated here for brevity. The trigger spring 23 is housed in a conical seat 25 in the guard 20 and has its upper end inserted in a cup 27. The glass 27 acts, by means of the snap spring 23, on a first action surface 29 and on a second action surface 31 of the hammer 3. The action surfaces 29 and 31 are connected by an edge 33 and arranged at a certain angle to each other. Advantageously, the trigger spring 23 acts on the hammer 3 at a point defining a lever arm with the fulcrum of said hammer in such a way that the lever arm is variable between the cocked position and the percussion position. INTERNATIONAL PATENTS Ingg. Zini, Marai^M^ C. srl -8According to the present invention, the mechanism 1 comprises a fast firing engagement tooth 5 housed in a seat 51, formed in the body 20 of the guard, via a pin 10. The quick-fire catch tooth 5 is configured to ensure the retention of the hammer 3, as described in detail below. The hammer 3 includes a mount 73 which locks the rapid fire locking tooth 5 in the cocked position, until the bolt 8 has completed its travel. The mechanism according to the invention also comprises a quick-fire disconnector 41 integrated on a connecting rod 4 hinged to the bolt 8. Alternatively, according to an embodiment not illustrated in the figures, the quick-fire disconnector is integrated into the bolt body. The quick-fire catch tooth 5 is pushed onto the hammer 3 by a hook spring 6. A pin 7 prevents the rapid fire catch tooth 5 from rotating too far when the hammer 3 is lowered. According to the present invention, the bolt has a discharged plane 81 which partially accommodates the hammer 3, when the bolt 8 itself is retracted, i.e. open, as visible in figure 12. The operation of the trigger mechanism according to the invention is as follows. INTERNATIONAL PATENTS Eng. Zini, Marassi / C. srl Figures 3-6 illustrate the trigger guard and bolt assembly in the ready-to-fire condition. When pressure is applied to the trigger 11, the sear tooth 9 acts on the first tooth 77 of the hammer 3, releasing the hammer and thus causing the strike. The hammer 3 is then free to rotate, loaded by the trigger spring 23, until it strikes the bolt striker 8. The bolt striker is not visible in the figures. When firing, the bolt 8 moves back, rearming the hammer 3, as shown in figures 7-10. During the entire firing cycle, trigger 11 is still pulled, as only approximately 200 ms have passed since the shot, and it is therefore necessary to disconnect the trigger chain in order to be able to repeat the next shot with a subsequent pressure on trigger 11. The safety catch tooth 2 of the trigger 11 intercepts the hammer 3, thanks to the second tooth 17 of the hammer 3 itself. This way, even though the trigger is still pressed, hammer 3 remains cocked. By releasing the trigger 11, the grip of the hammer 3 on the sear tooth 9 is ensured, even before it escapes from the safety catch tooth 2, returning the system to the initial configuration of the weapon ready to fire, visible in figures 3-6. The safety catch tooth 2 therefore has a INTERNATIONAL Mr. Zini, Maran! -10essential function: in fact, in the absence of the safety catch tooth 2 and with the sear tooth 9 not engaged (trigger pressed), the hammer 3 would rest on the bolt 8 in closing, without striking, and this would force the user to manually retract the bolt 8 to repeat the rearming cycle, also ejecting a still loaded cartridge as he would be unable to repeat the shot. A skilled and highly trained user may be able to press the trigger multiple times during the same cycle. In this case there is the risk, when the bolt 8 retracts and recocks the hammer 3, of releasing the trigger 11 thus disconnecting the safety catch 2 and pressing it again allowing the hammer 3 to be free to rest on the bolt 8 until it closes, in the condition schematized in figure 25. As in the absence of the safety catch 2, also in this case the hammer 3 would rest on the bolt 8 when closed without striking and this would force the user to manually retract the bolt 8 to repeat the rearming cycle, also ejecting a still loaded cartridge as he would be unable to repeat the shot. The present invention prevents the failure to strike that would occur in the case described above. In fact, according to the present invention, the guard 20 is modified by forming a housing for the coupling tooth. INTERNATIONAL (Bka / ETTI -11- Eng. Zini, Marane^l·# ®. srl quick shots 5. The quick-fire locking tooth 5 ensures the retention of the hammer 3 even in the case described above. The hammer 3, equipped with the cocking mechanism 73, is blocked in the cocked position by the rapid fire locking tooth 5, until the bolt 8 has completed its travel. Only at this point does the quick-fire disconnector 41, integrated on the connecting rod 4, or alternatively on the bolt body, switch the quick-fire locking tooth 5, releasing the hammer 3 and causing the shot to be fired only when the bolt is fully closed. This fast firing hook tooth 5 is pushed onto the hammer 3 by the hook spring 6 while the pin 7 prevents the extra rotation of the tooth 5 when the hammer is lowered. The calibration of the model, in particular the relative position of the holes on the guard, is fundamental for the synchronization of the kinematic chain. The user who has fired can therefore repeat the shot without even noticing this additional step due to these modifications which have therefore ensured the same user experience that would have been obtained by pressing the trigger as quickly as possible, respecting the firing cycle times. The system according to the invention would also allow, in markets where the sale and possession of automatic repeating weapons are permitted, to have an automatic weapon. INTERNATIONAL Eng. Zini, Maraw EVETS C. srl In particular, the absence of the safety catch tooth, which without this system would cause the primer to fail to strike the cartridge, would cause a continuous firing cycle as long as the trigger is pressed. A possible fire selector that switches this tooth on or off could allow the selection of the most appropriate fire mode. Figures 17-20 illustrate the system in the fast firing condition with the closure almost completed, according to the present invention. If a very fast shooter, after firing with a traditional standard system, were to release the trigger and re-press it when the bolt was in the rearward position, therefore above the hammer, when the bolt closed the safety catch would intercept it, as if the second trigger pull had not been applied. In fact, in a position similar to that in Figure 12, when the bolt is rearward (open), the hammer is cocked by the bolt, in a traditional system. In this configuration, the advantages of the possible presence of the fast-firing catch would thus be nullified. According to the present invention, the bolt 8 equipped with the unloaded plane 81 allows, in this situation, the hammer 3 not to interfere with the safety catch tooth 2 and the cocking is therefore avoided in favour of the fast firing catch tooth 5. INTERNATIONAL Ingg. Zini, Marand (EVETTI C. srl -13In this way, as in other situations, according to the present invention the hammer 3 strikes as soon as the bolt 8 closes, giving the user the perception of firing the second shot as soon as possible, even if this is postponed by a fraction of a second with respect to the second pressure of the trigger 11. In practice, it has been found that the invention achieves the intended task and purposes by creating a new trigger mechanism for firearms specifically designed to prevent the hammer from failing to engage the trigger assembly if the user repeats the shot at such a speed that the striker fails to fire and therefore cannot fire the next shot. The trigger mechanism according to the invention is susceptible to numerous modifications and variations, all of which fall within the scope of the inventive concept; furthermore, all details may be replaced with technically equivalent elements. Naturally, the materials used, as well as the dimensions, can be any according to the needs and the state of the art.

Claims

1. Trigger mechanism for firearms comprising a trigger (11) hinged to a structure (20) of a guard and equipped with a sear tooth (9); a hammer (3) hinged to said guard (20) and loaded by an elastic element (23) until it strikes a firing pin present in a bolt (8); said hammer (3) comprising a first tooth (77) suitable for engaging said sear tooth (9) of said trigger (11); said trigger (11) having a safety catch tooth (2) suitable for engaging a second tooth (17) of said hammer (3); said safety catch tooth (2) being hinged to said trigger (11) and being configured to effect a slight backward movement in contrast with an elastic element (19); said trigger mechanism being characterised by the fact that it comprises a fast firing engagement tooth (5) housed in a seat (51) formed in said guard (20);said fast firing catch tooth (5) being configured to retain said hammer (3).; 2. Trigger mechanism, according to claim 1, characterised in that said hammer (3) comprises a mount (73) configured for locking in the cocked position by said fast firing locking tooth (5), until said bolt (8) has completed its travel.

3. Trigger mechanism, according to claim 1 or 2, characterised in that it comprises a quick-fire disconnector (41) integrated on a connecting rod (4) hinged to said shutter INTERNAZIONALI Ingg. Zini, Marana VETTI . srl (8) .

4. Trigger mechanism, according to one or more of the preceding claims, characterised in that said fast firing catch tooth (5) is pushed onto said hammer (3) by a hook spring (6).

5. Trigger mechanism, according to one or more of the preceding claims, characterised in that said fast firing engagement tooth (5) comprises a pin (7) configured to prevent extra rotation of said fast firing engagement tooth (5) when said hammer (3) is lowered.

6. Trigger mechanism, according to one or more of the preceding claims, characterised in that said bolt comprises a discharged plane (81) configured to at least partially accommodate said hammer (3), when said bolt (8) is retracted, i.e. open.

7. Trigger mechanism, according to one or more of the preceding claims, characterised in that said elastic element comprises a trigger spring (23) housed in a conical seat (25) formed in said guard (20); said trigger spring (23) having an upper end inserted in a cup (27): said cup (27) acting, by the effect of said trigger spring (23), on a first action surface (29) and on a second action surface (31) of said hammer (3); said action surfaces (29, 31) being connected by an edge (33) and arranged at a certain angle to each other; said trigger spring (23) acting on said hammer (3) at a point defining a lever arm with the fulcrum of said hammer in such a way that said lever arm is variable between the cocking position and the percussion position.

8. Trigger mechanism, according to one or more of the preceding claims, characterised in that, during a trigger, said safety catch tooth (2) intercepts said hammer (3) by the action of said second tooth (17) and said hammer (3); said hammer (3) remaining cocked when said trigger (11) is still pressed; by releasing said trigger (11) said hammer (3) is caught on said trigger tooth (9), before it escapes from said safety catch tooth (2), bringing the system back to an initial configuration of the weapon ready to fire; said safety catch tooth (2) preventing said hammer (3) from resting on said bolt (8) when closed, without striking.

9. Trigger mechanism, according to one or more of the preceding claims, characterised in that, during a shot, said hammer (3), equipped with said bolt (73), is blocked in the cocked position by said fast firing catch tooth (5) until said bolt (8) has completed said stroke; said fast firing disconnector (41) switching said fast firing catch tooth (5), releasing said hammer (3) and causing the shot to be fired only when said bolt is fully closed; said fast firing catch tooth (5) being pushed onto said hammer (3) by the hook spring (6) while said pin (7) prevents an extra rotation of said tooth (5) at the moment in which said hammer is