WO2009000218A2

WO2009000218A2 - Double action trigger mechanism for semi-automatic pistol

Info

Publication number: WO2009000218A2
Application number: PCT/CZ2008/000063
Authority: WO
Inventors: Rostislav Hrubos; Jaroslav Rezek; Ivan Filko
Original assignee: Ceska Zbrojovka AS
Current assignee: Ceska Zbrojovka AS
Priority date: 2007-06-26
Filing date: 2008-06-11
Publication date: 2008-12-31
Anticipated expiration: 2009-12-26
Also published as: IL202394A0; EP2160562A2; IL202394A; CZ301749B6; WO2009000218A3; CZ2007434A3; EP2160562B1

Abstract

In the double action trigger mechanism of the semi-automatic pistol, the body of which comprises a frame (1) with a magazine channel (16), slide (28), trigger (12) pivotally mounted in the pistol body, and a draw bar (15) joined with the trigger (12) for the transfer of the trigger (12) motion when being pulled, the draw bar (15) is located along one of the magazine channel (16) sides and pivotally connected with the trigger (12) for the movement of the draw bar (15) in the direction towards the rear end of the pistol when the trigger (12) is pulled. The draw bar (15) is preferably adapted for engagement with the lever (5) of the hammer (3) when puling the trigger (12) in the course of cocking of the hammer (3) from its front position against the force of the main spring (40).

Description

Double Action Trigger Mechanism for Semi-Automatic Pistol

Field of Invention

The present invention relates to double-action trigger mechanism for semi-automatic pistol.

Background of the Invention

There are known semi-automatic pistols, with the trigger mechanism consisting of single-arm draw bar. The expression "single-arm" in connection with "single-arm draw bar" means draw bar consisting of only one bar placed along the single side of the magazine channel. Double arm then comprises two arms, each of them being placed along one side of the magazine channel .

The trigger mechanism of pistols having single-arm draw bar operates in many cases in the single action mode (e.g. as it is with the CZ 75 ST or CZ 75 M pistols) . Disadvantage of some double-action trigger mechanisms with single-arm draw bar is usually high trigger pull weight and inconsistent operation, resulting from passive resistance in the course of transfer of forces .

This disadvantage was to a great extent abrogated by the introduction of double-action trigger mechanism utilized for example with the CZ 75 pistol and its clones, where the trigger mechanism is outfitted with symmetrical double-arm bar, which has no immediate contact with the hammer, but movement of the hammer is controlled by means of interposed connecting link, which facilitates transmission of force from draw bar to the hammer and partially eliminates incipient friction. This solution achieves that the trigger pull weight curve is not steep and there is overall reduction of the trigger pull weight making its operation more consistent and uniform. This design also attains higher comfort and accuracy of fire as with this solution there is almost no "trigger jerk" resulting from high and non-uniform trigger pull weight.

Disadvantage, inherent in semi-automatic pistols with double- action trigger mechanisms having two-arm draw bar especially those with high capacity magazines, is necessity to use the frame with extended width and that particularly with large calibre semi-automatic pistols (e.g. 40 S&W etc.). The terms of production entail another disadvantage in complex and expensive manufacturing process of double-sided draw bars and other associated parts and components.

Further, it is necessary to mention also existence of double- action trigger mechanisms comprising single-side bar which when the trigger blade is squeezed is driven forward in the direction of fire. Disadvantage of these versions is often already mentioned higher trigger pull weight and at the same time its relative complexity and comparatively expensive production of used parts and components .

Summary of the Invention

The above mentioned shortcomings are eliminated to maximum by utilizing double-action mechanism of semi-automatic pistol, the body of which comprises frame with the magazine channel, slide, the trigger mounted pivotally in the body and the draw bar connected with the trigger for the transfer of trigger motion while being pulled, the principle of which consists in the fact that the draw bar is placed along one of the magazine channel sides and is pivotally connected with the trigger for movement of the draw bar in the direction towards the rear of the pistol while the trigger is pulled.

According to one of advantageous embodiments of double action trigger mechanism the draw bar is arranged for engagement with the hammer lever during pull of the trigger in the course of the hammer cocking from its front position against the force of the main spring. In such a case it is advantageous when double action trigger mechanism includes roller, rotatable around fixed axis for rolling engagement with functional surface created on the draw bar at the final stage of the hammer cocking for the change of draw bar position in such a manner that it is released from its engagement with the lever and thus the hammer is tripped and under the force of the main spring strikes against the primer.

According to another advantageous embodiment the double-action trigger mechanism includes the sear for intercepting the hammer after its cocking automatically following the fire by movement of the slide towards the shooter or after retracting the hammer manually for the first shot using hammer's head serrated surface. In such a case it is advantageous when the drawbar is adapted for engagement with the sear after the hammer interception for the hammer release and its striking under the force of the main spring against the primer.

It is advantageous, when the draw bar is adapted for the engagement with the firing pin block lever to unlock the firing pin before the hammer is released.

Intended invention objective is to eliminate to the maximum aforesaid shortcomings being inherent in the existing double action trigger mechanisms, which objective is achieved by utilizing single-arm draw bar controlled by the trigger, which allows double action of the serai-automatic pistol and is guided by the roller and which is pushed for the reason of the trigger pull weight reduction in the direction towards the shooter, further by the new design of the ejector having more functions, by new design of the trigger pin fixation.

In the production terms, the design of the trigger mechanism according to the present invention is advantageous in that the parts and components used are, compared to parts and components of known semi-automatic pistols having double action trigger mechanism, simplified and restricted to parts of spindle character, stamped parts, or parts made by sintering under high temperatures and pressure into mould, without any requirements for further surface treatment.

Brief Description of the Drawings

The present invention will be made, more apparent using description of its advantageous embodiment with reference to herein attached schematic drawings, in which Fig. 1 illustrates broken-out section of the semi-automatic pistol with the trigger mechanism in the condition when the hammer is being cocked from its front - initial position, Fig. 2 is a broken-out section of the semi-automatic pistol with the trigger mechanism in the condition of the final stage of release of the hammer being cocked from its front - initial position, Fig. 3 is a broken-out section of the semi-automatic pistol with the trigger mechanism in the condition, where the hammer is cocked and intercepted by the sear, Fig. 4 is a broken-out section of the semi-automatic pistol with the trigger mechanism in the condition of the final stage of the hammer release from its cocked position; Fig. 5 is a broken- out section of the semi-automatic handgun with the trigger mechanism in the condition after a cartridge discharge, and Fig. 6 is an exploded view of the frame (in broken-out section) of the semi-automatic pistol, part of the slide and part of the trigger mechanism in disassembled condition.

Description of the Preferred Embodiment

As evidenced by the attached illustrations, pin 2 with pivotally mounted hammer 3 thereon is embedded at the rear part of the frame 1 of the semi-automatic pistol with double action trigger mechanism according to the invention. At the body of the hammer 3 is sited the pin 4 with pivotally attached lever 5 of the hammer 3 ended with the projection 6. This lever is at its upper part formed into abutting surface 7 which rests against pin 8 sited in the frame 1. The projection 6 of the lever 5 of the hammer 3 comes into contact with the guide surface 9 formed in the frame 1. The pin 2 of the hammer 3 is secured in its position by the surface 10 of the lever 5 which is in engagement with the slot 11 formed on the pin 2 crosswise to its longitudinal axis.

The front part of the frame 1 houses the trigger 12 pivoted on the pin 13. The trigger 12 is by means of pin 14 which is close-connected with the draw bar 15 joined-up with the draw bar 15 consisting of single-arm, which is placed at the one side of the magazine channel 16 and is loaded with the spring 17. On the draw bar 15 is formed a lug 18 designed for engagement with a boss 19 made at the lever 5 and with the projection 25 made at the sear 26 of the hammer 3. The lug 18 comes at certain moment also into engagement with the nose 21, which is made at the lever 20 of block of firing pin 39. The draw bar 15 is provided with inclined surface 22, which in the final stage of cocking motion comes into contact with the rotating roller 23 which is axially mounted on the pin 8. The draw bar 15 is further provided with a lug 24 which comes into engagement with the surface 27 of the slide 28 when the sear

26 of the hammer 3 is about to intercept the hammer 3 in its cocked position.

At the rear part of the frame 1 on the pin 8 is pivotally attached the sear 26 of the hammer 3 loaded by the spring 29, and further, on the pin 8 is pivotally attached the lever 20 of the firing pin block. The pin 8 is secured in its position by the ejector 30 which is with its surface 31 in the engagement with the crosswise slot 32 made up on the pin 8. Further at the rear part of the frame 1 is pivotally mounted the safety 33 which is made of stud 34 and safety control 35 and is in its position secured by the cut 36 of the ejector 30 which is loaded by the spring 37 and is in engagement with crosswise slot 38 made up on the stud 34 of the safety 33.

The slide 28 also houses a firing pin 39, which is activated by the hammer 3 loaded with the main spring 40.

Further description concerns to the operation of trigger mechanism for the discharge from the front position of the hammer and discharge from the rear position of the hammer.

Discharge from the front position of the hammer 3:

When pulling the trigger 12 (see Fig.l), the trigger 12 moves around its pin 13 towards the shooter and the single-arm draw bar 15 connected with its pin 14 with the trigger 12 shifts in the same direction. In the course of this movement the draw bar 15 pushes with its lug 18 against the boss 19 of the hammer lever 5, which is connected by means of the pin 4 with the hammer 3, thereby actuating cocking of the hammer 3. In the course of this movement the lever 5 is closely guided by its projection 6, the angled lower section of which is moving along guiding surface 9 of the frame 1. The lever 5 of the hammer 3 has at its upper section an abutting surface 7 (illustrated in Fig. 6), which rests against the pin 8 (illustrated e.g. in Figs. 3 and 6) seated in the frame 1. The draw bar 15 is pressed into engagement with lever 5 by spring 17 housed in the frame 1, acting against the draw bar 15 from below. At the final stage of cocking motion illustrated in the Fig. 2, the inclined surface 22 made on the draw bar 15 comes onto rotatable roller 23 which is rotatably mounted on the pin 8, whereas the draw bar 15 is lowered as far as the boss 19 of the lever 5 is released from the engagement with lug 18 on the draw bar 15. This trips the hammer 3, which under the force of the main spring 40 strikes the firing pin 39 and thus discharges the cartridge in the barrel . Before the moment of disengagement between the lug 18 of the draw bar 15 and the boss 19 of the lever 5 of the hammer 3, the draw bar 15 with its lug 18 presses onto the nose 21 of the lever 20 of the block of the firing pin 39, which pivots around the pin 8 and with its surface 42 lifts element 43 of the block of the firing pin 39, which is positioned in the slide 28, thus unlocking the firing pin 39.

Discharge from the rear position of the hammer 3 :

During automatic function of the pistol, after discharge of a cartridge the hammer 3 is automatically cocked when the slide 28 travels rearward towards the shooter, or the hammer 3 can be also cocked manually for the first shot using hammer head' s serrated surface 45 illustrated in Fig. 6. In this case, as shown in Fig. 3, the cocked hammer 3 is intercepted by the sear 26 loaded by the spring 29. In the course of cocking of the hammer 3 the draw bar 15 is together with the trigger 12 retracted partially to the rear towards shooter. This retraction of the draw bar 15 and of the trigger 12 in the rearward direction is provided by the projection 6 of the lever 5, which during cocking of the hammer 3 carries the draw bar 15, which is joined by means of the pin 14 with the trigger 12, on the jag 41 of the draw bar 15.

As shown in Fig. 4, when pulling the trigger 12, the lug 18 of the draw bar 15 presses on the nose 21 of the firing pin block lever 20 which pivots around the pin 8. The lever 20 with its surface 42 lifts element 43, thereby unlocking firing pin 39, and subsequently the lever 20 with its cog 44 acts on the projection 25 of the sear 26 of the hammer 3. The sear 26 partially pivots around the pin 8 thereby releasing the hammer 3 whereby the cartridge is discharged.

After discharge, as per condition illustrated in Fig. 5, the slide 28 travels rearward towards the shooter and during this movement the hammer 3 is again automatically cocked. In order that the sear 26 could again intercept the hammer 3 in its cocked position, the surface 27 of the slide 28 comes onto lug 24 formed on the draw bar 15 and the draw bar 15 is pressed down against the force of the spring 17. At the same time the lug 18 of the draw bar 15 is disengaged from the nose 21 of the lever 20. The lever 20 moves unhindered around the pin 8 and is not acting by its cog 44 on the projection 25 of the sear 26 thereby liberating the sear 26 which under the force of the spring 29 again intercepts the hammer 3 in its cocked position.

After releasing the trigger 12 in condition as shown in Fig. 3 the draw bar 15 loaded with the spring 17 is again lifted and is re-engaged with lever 20 of the firing pin block 39 and the handgun is ready to discharge another shot.

Claims

1. Double action trigger mechanism of the semi-automatic pistol, the body of which comprises a frame (1) with a magazine channel (16) , slide (28) , trigger (12) pivotally mounted in the pistol body, and a draw bar (15) joined with the trigger (12) for the transfer of the trigger

(12) motion when being pulled, characterized in that the draw bar is located along one of the magazine channel (16) sides and is pivotally connected with the trigger (12) for the movement of the draw bar (15) in the direction towards the rear end of the pistol when the trigger (12) is pulled.

2. Double action trigger mechanism according to claim 1, characterized in that the draw bar (15) is adapted for engagement with the lever (5) of the hammer (3) when puling the trigger (12) in the course of cocking of the hammer (3) from its front position against the force of the main spring (40) .

3. Double action trigger mechanism according to claim 2, characterized in that it comprises roller (23) rotatable around fixed axis for rolling engagement with functional surface (22) made on the draw bar (15) in the final stage of the hammer (3) cocking for changing position of the draw bar (15) in such a way that the draw bar (15) is liberated from its engagement with the lever (5) and thereby the hammer (3) is released and strikes against the primer (39) under the force of the main spring (40) .

4. Double action trigger mechanism according to any one of the preceding claims, characterized in that it comprises the sear (26) of the hammer (3) for intercepting the hammer (3) after its cocking automatically after discharge by the means of movement of slide (28) towards the shooter or after its manual cocking for the first shot using hammer serrated surface (45) .

5. Double action trigger mechanism according to claim 4, characterized in that the drawbar (15) is adapted for engagement with the sear (26) after intercepting the hammer (3) by the sear (26) for releasing the hammer (3) and its striking under the force of the main spring (40) against the primer (39) .

6. Double action trigger mechanism according to claim 3 or 5, characterized in that the draw bar (15) is adapted for engagement with the lever (20) of the firing pin (39) block for unlocking the firing pin (39) before the hammer

(3) release.