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(11) | EP 0 434 160 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Method for the timely opening of a cartridge magazine in a shotgun and the device for implementing said method |
| (57) In a shotgun in which a cartridge magazine (23) is provided with closure and opening
means (27) removably retained in the closure position by a cartridge lifter (26),
a slider (31) is associated with a cock-engagement lever (9) and cooperates with the
lifter (26) to retain the means (27) in the closure position. |
[0001] This invention relates to a method for the timely opening of a cartridge magazine in a shotgun preferably but not exclusively of semiautomatic type, of the type comprising a trigger, a cock linked to the trigger by a cock-engagement lever, magazine closure and opening means removably retained in the closure position by a cartridge lifter, and a slider mobile between a first forward position in which it cooperates with the lifter to retain said means in the closure position, and a second position withdrawn from said lifter.
[0002] A basic requirement of this type of shotgun is the need to ensure that during each gun operating cycle triggered by the firing of a cartridge a new cartridge is fed from the magazine to the cartridge chamber.
[0003] This feed is achieved by a scoop-shaped lifter, which is generally interlocked with the cock and raises the new cartridge, already fed onto it by the cartridge magazine, into axial alignment with the gun cartridge chamber.
[0004] Magazine closure and opening means act at the breech end of the cartridge magazine by being moved in a determined synchronous sequence with the lifter movements.
[0005] On firing, the cock during its travel towards the percussion pin and via a slider controlled by it causes the lifter to move away from said magazine closure and opening means, so opening the magazine with consequent passage of a new cartridge onto the lifter.
[0006] The timing of the opening of the cartridge magazine or the consequent positioning of a new cartridge on the lifter is particularly critical, as this is raised towards the cartridge chamber simultaneously with the return of the breech-block to close said chamber and only if the new cartridge has already been located on the lifter.
[0007] In feed devices of the known art it has been found that a new cartridge may have only partially reached the lifter, or indeed not reached it at all.
[0008] This is due to the inevitable recoil force which acts on the entire gun on firing, and tends to urge the cartridge towards the muzzle end of the cartridge magazine so opposing the operation of the cartridge feed spring normally provided in the magazine.
[0009] An even slight delay in the movement of the cartridge towards the lifter can result in it not being raised, with consequent interruption in the operation of the gun, which finds itself with its breech-block retracted into the open position but with the cartridge chamber empty.
[0010] This drawback, which undermines the operational reliability of the gun, is mostly evident when firing so-called "strong" cartridges. The technical problem to be solved by the present invention is therefore to provide a method by which the cartridge magazine is opened in good time during each gun operating cycle for any type of ammunition and which at the same time ensures reliable feed of a new cartridge to the cartridge chamber.
[0011] This problem is solved according to the invention by a method of the aforesaid type characterised in that the slider is retracted by said cock-engagement lever.
[0012] This ensures correct operation of the cartridge feed spring provided in the magazine, the spring thus being able to position a cartridge of any type of ammunition on the lifter before percussion and before the recoil force consequent on firing is able to act on it.
[0013] The characteristics and advantages of the invention will be more apparent from the description of one embodiment of the method according to the invention, described hereinafter with reference to the accompanying drawings which show a non-limiting example of a device according to the invention. In said drawings:
Figure 1 is a schematic view of a device according to the present invention;
Figure 2 shows the device of Figure 1 to an enlarged scale;
Figure 3 shows the device of Figure 2 during an operational stage;
Figure 4 is a plan view of a detail of the device of Figure 1;
Figure 5 shows the detail of Figure 3 during an operational stage;
Figures 6 and 7 are two perspective views of some details of the device of Figure 1.
[0014] In said figures the reference numeral 1 indicates a semiautomatic gun, of which Figure 1 shows a part of the breech portion, comprising a device 2 described in detail hereinafter and arranged to releasably lock a cartridge magazine indicated by 23. In the considered example, reference will be made specifically to a twelve-gauge semiautomatic shotgun.
[0015] For a clearer understanding of the structural and operational characteristics of the device of the present invention, in the following description and claims the terms "front", "rear", "advanced" and "retracted" refer to the gun as held.
[0016] The gun 1 comprises a body 3 supporting a release mechanism 4 of known type, comprising a cock 10 linked to a trigger 5 via a pair of substantially bar-shaped levers 8 and 9, these being the release lever and the cock-engagement lever respectively.
[0017] The trigger 5 is pivoted to the body 3 by a respective pin 6 and is provided at its top with a pin 7 extending transversely from an upper portion 5a of it. On said pin 7 there is pivoted the release lever 8, which is provided with respective spring means 11 mounted on a stem 12 extending from and integral with a central portion 8a of it.
[0018] The release lever 8 is provided at its front with a projection 8b arranged to cooperate, in the manner described hereinafter, with a rear wall of the cock-engagement lever 9.
[0019] The lever 9 is pivoted by a pin 13 to the body 3, within which it extends substantially perpendicular to the release lever.
[0020] More specifically, the cock-engagement lever 9 is pivoted at 13 within its central portion 9a, in which there is a side recess 14 housing spring means 35 comprising a wire spring 15 wound about said pin 13.
[0021] The wire spring 15 comprises opposing ends 15a, 15b acting respectively on a ledge 16 formed in the gun body 3 and on the upper end 14a of the recess 14 so as to constantly urge the lever 9 against the release lever 8. At its upper end 9b the lever 9 is provided with a tooth 17 for engaging the cock 10. At its lower end 9c the lever 9 is provided on its rear with a projection 9d of curved profile. The cock 10, pivoted to the body 3 by a respective pin 18, is provided with a counter-tooth 19 and is angularly mobile, under the action of the respective spring means 20, between a cocked position in which the counter-tooth 19 is engaged and retained by the engagement tooth 17 formed in the lever 9, and a firing position in which the cock 10 abuts against a percussion pin 21 slidingly mounted in a breech-block 22.
[0022] The magazine 23 which extends parallel to and below a barrel represented in Figure 1 by its longitudinal axis A-A, houses a plurality of cartridges 24 urged towards a feed chamber 25 by spring means of conventional type, not shown.
[0023] In said chamber 25 there acts an lifter 26 interlocked in known manner with the breech-block 22 and constantly urged downwards by known spring means, not shown in any figure. The lifter 26 cooperates with the breech-block 22 to feed the cartridges 24 to a conventional cartridge chamber, not shown. The lifter 26 is provided at its rear with a fork-appendix 26b between which there extends a pin 32 and on which the lifter is hinged. Moreover the lifter 26, pivoted to the gun body 3 by a pin 32, is provided at its front with a scoop-shaped appendix 26a which as described hereinafter forms a positive stop for the closure and opening. means 27 for the cartridge magazine 23.
[0024] Said means 27 comprise a plate-like lever 28 rotatably supported by a pin 29 and angularly mobile within the chamber 25 under the action of respective spring means 30 between two positions in which the magazine 23 is open and closed respectively.
[0025] The device 2 of the present invention comprises a plate-like slider 31 mounted to the side of the lever 9 and provided at its front with a notch 33 on which the scoop-shaped appendix 26a of the lifter 26 rests.
[0026] A slot 34 provided centrally in the slider 31, cooperating with pin 32, forms a track for the guided movement of the slider, between the fork appendix 26b of the lifter 26.
[0027] The slider 31 is also provided with respective return spring means 36 comprising a helical spring 37, the opposing ends of which engage against an appendix 38 extending rearwards from the slider and against a ledge 39 in the body 3.
[0028] In proximity to said appendices 38 the slider 31 comprises a projection 40, which extends laterally from it towards the lever 9 and is arranged to abut against its projection 9d, against which it is constantly urged by the spring means 36.
[0029] With reference to Figure 2 it can be seen that when the gun is in its rest state the notch 33 of the slider 31 retains the lifter 26 against the lever 28, which is thus maintained in the position in which it closes the cartridge magazine 23 against the spring means 30.
[0030] When in this position in which it closes the magazine 23, the cartridges 24 are retained therein by the front end of the lever 28.
[0031] The method of the invention will now be described with reference to the aforegoing description of the device 2 and to Figures 2 to 5.
[0032] Initially, the notch 33 of the slider 31 by maintaining the lifter 26 raised retains it against the lever 28, which therefore assumes the position in which it closes the cartridge magazine 23 as shown in Figure 4.
[0033] Then on pressing the trigger 5 the release lever 8 advances to consequently rotate the cock-engagement lever 9 about the pin 13 by virtue of the contrast between the projection 8b of the lever 8 and the rear wall of the portion 9b of the lever 9.
[0034] By virtue of the contrast between the projection 40 on the slider 31 and the projection 9d on the lever 9, during the rotation of this latter there is a simultaneous retraction of the slider 31. As the trigger 5 is further pressed, the cock-engagement lever 9 and the slider 31 reach the position shown in Figure 3, in which the counter-tooth 19 of the cock 10 disengages from the tooth 17 of the lever 9 to provide substantially simultaneous disengagement of the notch 33 of the slider 31 from the scoop-shaped portion 26a of the lifter. This latter can therefore swivel downwards away from the closure means 27 for the cartridge magazine 23.
[0035] At the moment in which the cock is released from the lever 9, the lever 28 is free to rotate towards the interior of the chamber 25 under the action of its spring means 30, with consequent opening of the cartridge magazine 23 (Figure 5).
[0036] This allows a cartridge 24 to enter the chamber 25 and be received by the lifter 26 substantially simultaneously with the release of the cock 10.
[0037] The cartridge 24 therefore becomes positioned on the lifter 26 during the travel of the cock 10 towards the percussion pin 21 and its positioning is practically complete when this latter is fired. After the release of the cock 10 and simultaneously with its travel the lever 9 and slider 31 are urged forwards by the wire spring 15 and by the helical spring 37 respectively.
[0038] The repositioning of the slider 31 is slidingly guided by the pin 32, which engages the slot 34 in the slider.
[0039] During the positioning of the cartridge 24 on the lifter 26, the lever 28, supported rotatable about the pin 29, is moved by the bottom of the cartridge into the position in which it closes the magazine 23.
[0040] During its rise towards the gun cartridge chamber and during its return to the chamber 25, the lifter 26 retains the lever 28 in the position in which it closes the cartridge magazine 23 against the spring means 30.
[0041] The method and device of the present invention therefore advantageously enable the closure means 27 for the magazine 23 to be controlled totally independently of the movement of the cock 10, so ensuring timely opening of the magazine.
[0042] As stated, at the act of firing, the new cartridge to be fed is already positioned on the lifter 26 and can therefore be located in the cartridge chamber of the gun 1 during the return of the breech-block 22 into position.
[0043] The movement of the cartridges onto the lifter 26 is therefore advantageously in no way impeded by the recoil force which arises following firing, thus substantially improving the reliability of gun operation.
[0044] The extremely simple structure of the device 2 of the present invention also advantageously means that a body 3 of simpler construction can be used, with consequent increase in the robustness of the gun and a reduction in its manufacturing cost. The device, which has been described with reference to a semiautomatic gun, can be likewise used in so-called "mixed action" guns, ie operable both manually and semiautomatically, and in manual "pump operation" guns.
1. A method for the timely opening of a cartridge magazine (23) in a shotgun of the type
comprising a trigger (5), a cock (10) linked to the trigger (5) by a cock-engagement
lever (9), magazine closure and opening means (27) removably retained in the closure
position by a cartridge lifter (26), and a slider (31) mobile between a first forward
position in which it cooperates with the lifter (26) to retain said means (27) in
the closure position, and a second position withdrawn from said lifter (26), characterised
in that the slider (31) is withdrawn by said cock-engagement lever (9).
2. A device for the timely opening of a cartridge magazine (23) in a shotgun of the type
comprising a trigger (5), a cock (10) linked to the trigger (5) by a cock-engagement
lever (9), magazine closure and opening means (27) removably retained in the closure
position by a cartridge lifter (26), a slider (31) mobile between a first forward
position in which it cooperates with the lifter (26) to retain said means (27) in
the closure position, and a second position withdrawn from said lifter (26), characterised
in that said slider (31) is associated with said cock-engagement lever (9), by which
it is moved towards said second position against respective return spring means (36).
3. A device as claimed in claim 2, characterised in that said slider (31) is plate-like.
4. A device as claimed in claim 2, characterised in that said return spring means (36)
comprise a helical spring (37).
5. A device as claimed in claim 2, characterised in that said slider (31) is interlocked
with said lever (9) by abutment between a slider projecting part (40) and a projection
(9d) provided on said lever (9).
6. A device as claimed in claim 2, characterised by comprising further spring means (35)
acting on said cock-engagement lever (9).
7. A device as claimed in claim 6, characterised in that said spring means (35) comprise
a wire spring (15).