GB2137322A - Breech locking system for self-loading firearms - Google Patents

Abstract

In a locked-breech, short recoil, pistol type firearm, the breech block slide (B) is provided with a separate locking block (E) engageable with both the barrel (C) and the slide (B) and accommodated between the underside of the barrel (C) and the upper surface of a movable trigger guard (D). Hold-open means (X) are provided operable, in the absence of cartridges in a magazine and in the breach to allow the slide (B) to be held in the fully retracted position and simultaneously to release the trigger guard (D) for limited forward and downward movement, the trigger guard being provided with means which on movement of the trigger guard cause the locking block (E) to disengage from the barrel (C), whereby the barrel can be removed without the need for further disassembly of the firearm. <IMAGE>

Description

SPECIFICATION Breech locking system for self loading fire arms This invention relates to fire arms ofthe self loading, locked breech, short recoil, pistol type, in which a separate locking block is employed, and moreparticularlytofirearmsofthekind having means for automatically locking the barrel and breech block together during the discharge ofthe cartridge in the breech, for the purpose of ensuring positive obturation ofthe cartridge casewallstothe breech chamber until the high pressure period ofthe powder gases is over, and then to automatically allow the breech block slide to separatefrom the barrel and permitthe extraction ofthe cartridge case safely.

The usual practice in self loading breech pistols is for them to employ a barrel locking to the slide, either by studs, ribs, or other means, and rotated, cammed, or otherwise moved out of engagement with the slide afterthe end ofthe high pressure period ofthe cartridge powder gases, orto employ a separate block to lock barrel to slide during the aforesaid high pressure period. The usual practice in self loading locked breech fire arms isforthe residual pressure in the barrel interior plus the inertia of the barrel and slide moving rearwards in reaction to the projectile's discharge to disengage whatever lock is employed, and to furnish the energy required to complete the cycle of cartridge case extraction and ejection, and the reloading ofthe barrel chamber with a loaded cartridge from a magazine in the fire arm.

It is usual in self loading locked breech pistols employing any of the breech locking systems previously mentioned to provide meansforthe removal of the barrel from the pistol. The usual practice is for a catch to be provided which, by manipulation or removal, allows the barrel and slide, together with, in most types of pistol, the recoil spring assembly,to be removed from the pistol main frame. Usually, the barrel can then be removed from within a recess in the slide. The disadvantage of thins practice in pistols is that in orderto remove the barrel for any reason, additional parts of the pistol must be removed from the main frame, and it is inconvenientto find accommodationforsuch parts which are liableto be exposed to dirt, be misplaced or be damaged.In the Walther P38 and Beretta models 951 and 92, the locking block is accommodated in a recess underthe rear ofthe barrel. Although the Walther locking block is easily detached from the barrel it is possible to reassemblethe pistol with the block absent, resulting in a very dangerous situation should the pistol then be fired with a normal ball cartridge. The Beretta pistols require tools to detach the locking block. Greater convenience is provided by certain pistols using low pressure cartridges and not requiring a locked breech, thataliowthe barrel alone to be removed initially, with the restofthe pistol intact.

It is, therefore, an object ofthe present invention to provide for self loading pistols using high pressure cartridges, a system that provides a positive lock between barrel and breech block or slide during the high pressure period of the firing cycle, and that allows the normal operation of such a pistol orfire arm, while also providing thatthe barrel alone can be removed from the fire arm when required.

It is another object of the invention to simplifythe manipulations involved in disassembling and assembling a self loading pistol orotherfire arm.

It is another object of the invention to provide a locking blockfor a self loading pistol or otherfire arm that is easily removed but is an essential part ofthe pistol orotherfirearm, and cannot be left out on assembly.

It is another object ofthe invention to provide a breech locking system for a self loading pistol or other fire arm that does not require tools to assemble and disassemble.

It is a subsidiary object ofthe invention to provide means of indication to indicate to the user when the inserted cartridge magazine is empty.

Finally, it is an objectto provide a breech locking system for a self loading pistol or otherfire arm which is of simple construction and cheap to manufacture.

According to the invention, there is provided a self loading fire arm of the locked breech, short recoil pistol type having a barrel and a breech block slide provided with a separate locking block accommodated between the underside of said barrel and the upper surface of a movable trigger guard, said locking block having means for positively locking the barrel to the slide during the high pressure period of the firing cycle ofthe fire arm and means for releasing the slide from the barrel during the remainder ofthe firing cycle, said trigger guard being normally locked to the frame, and hold open means operable in the absence of cartridges in a magazine and in the breech to allow said slide to be held inthefully retracted position and simultaneously to release said trigger guard for limited forward and downward movement, said trigger guard being provided with means which on said movement cause said locking blocktodisengage from the barrel, whereby the barrel can be removed without the necessityforfurther disassembly ofthe fire arm.

An embodiment of the invention is shown in the drawings and will be described in greater detail hereinafter.

Figure 1 ofthe accompanying drawings represents, partly in elevation and partly in longitudinal vertical section, a self loading semi-automatic pistol provided with means constructed and arranged in accordance with this invention for locking and unlocking the slide and barrel together during the firing cycles ofthe pistol, and means to allow the pistol to be disassem bled, showing the pistol in battery position, cartridge in chamber, locking block forward, slide locked to barrel by locking block; Figure 2 is a part elevation, part longitudinal vertical section ofthe upper part of the pistol in battery position; Figure3is a part elevation, part longitudinal vertical section of the upper partofthe pistol during a period ofthefiring cycle;; Figure 4 is a part elevation, part longitudinal vertical section of the upper part ofthe pistol during a further period ofthefiring cycle; Figure 5is a part elevation, part longitudinal vertical section of the upper part of the pistol during a further period ofthefiring cycle; Figure 6is a part elevation, part longitudinal vertical section of the upper part ofthe pistol, with the slide in the rear locked position; Figure 7is a part elevation, part longitudinal vertical section ofthe upper part ofthe pistol, showing part of the operation to disassemble barrel from pistol; Figure Sis a similarviewto Figure 7 showing a furtherpartofthe operation to disassemble barrel from pistol;; Figure9shows on an enlarged scale and partlyin elevation details from Figure 8 ofthe trigger guard and frame; Figure 10 shows on a reduced scale a part elevation of the pistol with slide locked to rear; Figure 11 shows on a reduced scale a part elevation ofthe pistol with trigger guard in the position as in Figures; Figure 12 is a transverse vertical section of Figure 1 upon the dotted line 1; Figure 73is a transverse vertical section of Figure 1 upon the dotted line 3; Figure 14 is a transverse vertical section of Figure 1 upon the dotted line 2; Fiture 15is a perspective view ofthe locking block;; Figure iSis another perspective view of the locking block; Figure 17is yet another perspective view of the locking block; Figure iBis a perspective view ofthetrigger guard withtriggeraxis pin; Figure 19 is a perspective view ofthe slide hold open assembly; Figure 20 is a perspective view ofthe barrel; Figure 21 is a perspective view of a trigger guard spring; Figure 22 is a perspective view of an alternative trigger guard spring; Figure 23 is a perspective view ofthe upper frame; Figure 24 is a perspective view ofthe slide; and Figure 25 is a partial left side elevation of the pistol with the chamber loaded, hammer cocked, and the hold open catch in the midway position, indicating an empty magazine is held in the pistol.The dotted lines showtheupperand lower limits of the hold open catch.

The same letters of reference indicate corresponding parts in several Figures of the drawings.

In the self loading pistol represented in Figure 1, the barrel C and slide B are mounted on the frame A. The locking block E which rides on the surface D2 of trigger guard D, is engaged by means ofwing El into recess C1 in barrel C and recess B3 between slide recoil rails B1 and B4 and B2 and B5. The slide B and barrel C being held together by locking block wing El are thrustforward by recoil springs P1 and P2 compressed by rear guides R1 and R2 (not shown) acting upon frame wings A2 and A3, and retained in the slide by forward recoil guides Q1 and Q2 (not shown) by recoil springs retainer RR.The slide and barrel and locking blocktogether are th rust forward as a whole and thereby the groove E2 in the front locking block surface impinges on frame pin Al which is permanently held in the frame, the frame pin Al thereby restricting the forward motion of the whole slide, barrel and locking block combination. When the cartridge XX is fired by the firing pin S, which is thrown forward by hammerJ being rotated on axis pin EE by main spring BB, pressure is exerted equally on bullet XX1 and through breech insert Fto the slide.

During this period of high cartridge gas pressure while the bullet travels along barrel bore C2 as shown in Figure 3the slide and barrel recoil to the rear, locked together by the locking blockwing, until locking block surface E3 impinges on trigger guard cam surface D4.

The locking block is forced by the continuing rearward motion ofthe slide, asshown in Figure 4,to be cammed downwards by surface D4 until the locking blockwing extensions disengagefromthe rear surface of the slide recoil rails and thereby allow the slide to freely continue to the rear as shown in Figure 4. The locking blockwing is still engaged in barrel recess Cl, and as the uppersurface of the locking block wing bears against the underneath surface of the slide recoil rails B1 and B4, and cannot move forward by locking block point E4 bearing on trigger guard cam D3, the barrel is held stationary by surfaces C4and C5 being engaged by the locking blockwing.

Duringthecammingofthelocking blockbysurface D4, the cartridge case is subjected to primary extraction, being withdrawn from barrel chamber C3 by extractor M.The bullet has leftthe barrel and residual pressure in the barrel and inertia will continue the rearward motion oftheslideto the position as shown in Figure 5. During the rearward motion ofthe slidethe cartridge case is extracted completeiyfrom the barrel chamber C3 and striking the nose L1 of ejector Lthe cartridge case is ejected from the pistol.

Acting under pressure ofthe recoil springs the slide will then move forward striking the base of cartridge YY in magazine T and feed the cartridge into the barrel chamber. The extractor will engage with the cartridge canelure W1 while the cartridge is being chambered.

Du ring the forward motion ofthe slide the position as shown in Figure 4 is attained. The cartridge is almost fully chambered when the slide recoil rail recesses align with the barrel recess thereby allowing the locking block wing free passage to rise.

The slide continues forward and the forward inner face ofthe slide B9 abuts the rear face ofthe barrel C6 thereby forcing the barrel also to move forward and barrel surface C4abutting the rearface ofthe locking blockwing E5 forces locking block point E4to be cammed up the trigger guard surface D3,thereby lifting the locking block wing into full engagement in both slide recoil rail recesses and the barrel recess.

Further pressure by the recoil springs forces slide and barrel and locking block, locked together bythe locking blockwing, forward until the whole are arrested by locking block surface E2 impinging on frame pin Al. When the last cartridge has been fed from the magazine into the chamberofthe barrel the magazinefollowerwill rise until its upper surface U2 impinges on the under surface ofthe slide. Atthis pointthe shelf U1 will have lifted the hold open unit (X, Y) to a point approximately midway between its lower rest position and the raised position it assumes when, as shown in Figure 7, the hold open is locking the slide in the rear position.This midway position can be seen as in Figure 25, and felt, and acts as an indicatorthat the magazine is empty and, at any point in time, at night, with the pistol orfire arm in theaimed position, or any other situation, the user has the knowledge that one cartridge remains in the chamber and that the magazine is empty. Thus the pistol orfire arm can be relbadedwithoutat anytime being rendered totally inoperable. This assumes no magazine safety is fitted to the gun; such a device would have to be removed to renderthe magazine indicator capable of serving its full purpose. In the pistol described no magazine safety is fitted. The magazine indicatorwould also operate should the chamber and magazine be empty.

Figure 25 showsthe empty magazine indicated position ofthe hold open catch, the dotted lines showing the upper and lower limit positions of the catch. The hold open unit consisting of an external member X having a pivot pin X2 and a rear pin X1, and an innermemberY having holesY2 and Y1 to receive the pins X2 and Xl, these pins passing through holes A4 and A5 in the frame, the hole A5 being sufficiently large to allow the pin X1 to move in it.

Upon the discharge of the last cartridge in the barrel chamberthe slide will recoil and the magazine follower will rise fully when the slide base moves clear ofthefollower, and thereby the magazine follower shelfU1 will raise the hold open fully, in this position as shown in Figure 6, the shelf has impinged on the hold open rear pin Xl, which moves within frame aperture A5, and forces the hold open and to rotate on its axis pin X2, which pivots in frame aperture A4 and since the hold open pins X1 and X2 pass through hold open inner holes Y1 and Y2 respectively, the whole hold open unit is made to pivot, compressing hold open spring Z againstthe forward part H 1 of the trigger bar H.As the whole hold open unit rotates the inner rear end Y3 ofthe inner member rises and locates in slide recoil rail recess B3 when the slide reaches thefull rearward position under recoil or when manually retracted. It will be observed that the forward end Y4 ofthe hold open inner member depresses as the rearY3 elevates, and the forward end moves to clearthe front of stud D1 which is permanently fixed transversely in the trigger guard cam lug D5. It is only in this position that the trigger guard can be moved forward againstthe resistance of the trigger guard spring, thus during all firing operations of the pistol, the trigger guard cannot move forward.

To remove the barrel from the pistol the slide is locked to the rear by the hold open unit as previously described and the magazine is removed by depressing from the left or right side ofthe pistol the magazine catch plunger UU which will retractthe nose VV1 of the magazine catch VV which is forced to the rear by spring WW.The forward inner surface D6 of the trigger guard is pushed forward, as shown by the arrow in Figure 7, and thereby the locking block which is seated in the trigger guard recess D9 will be forced forward and impinge on the frame pin Al. The trigger guard surface D7will move clear of frame point A6 and the trigger guard can be moved downwards, the trigger guard and locking block will then be rotating on the frame pin Al. The rotation ofthe trigger guard will be arrested bythetrigger bar contacting frame surfaceA7 and frame ledge A6will seat in trigger guard detent groove D8.The locking block, when in its lowered position within the trigger guard, will com pletely disengage the locking block wing from barrel recess C1 leaving the barrel free to move forward on the runners C7 sliding in theframe guides A8 each side, with reference to Figures 12 and 20 and 23. The barrel will slide clear oftheframe and when the hold open unit is disengaged from the slide, the slide can be slid forward offthe frame. To remove the locking blockthetriggerguard is returned to the position as shown in Figure 10 and with the barrel and slide detached from the frame the locking block can be removed upwards from the frame.To reassemble the slide and barrel to make the pistol operational the trigger guard with the locking block is put in the position as shown in Figure 8. The slide is mounted on the frame with the slide guides B8 engaged with frame runners A9 and held in the rear position with the hold open catch. The barrel is then mounted in the frame with the barrel runners in the frame guides and slid to the rear until barrel face C5 abuts with the forward face E6 of the locking block.The trigger guard is then pivoted upwards which engages the locking block wing to the position as Figure 7, and the trigger guard spring will then force the trigger guard and locking blockand barrel rearwardstothe position in Figure 6, the rearward motion ofthe trigger guard, and thus the whole, being arrested by frame pin Al 0 which is permanently mounted transversely in the frame.

If no magazine is in the pistol, the hold open unit can be operated manually by rotation ofthe outer member Xto hold the manually retracted slide in position.

When the trigger guard is in the Figure 8 position the trigger axis pin DD can be extracted from either side of the trigger guard to permit the trigger G and trigger bar H to be removed from the pistol.

The application ofthe invention to other small arms differs in no essential respect from its application to pistols ofthetype hereinbefore described.

The terms "horizontai" and "vertical" as used herein refer to the pistol or other fire arm when held in the normal firing position.

Claims (14)

1. A self loading fire arm of the locked breech, short recoil pistol type having a barrel and a breech block slide provided with a separate locking block accommodated between the underside of said barrel and the upper surface of a movable trigger guard, said locking block having means for positively locking the barrel to the slide during the high pressure period of the firing cycle ofthefire arm and means for releasing the slidefrom the barrel during the remainder of the firing cycle, said trigger guard being normally locked to the frame, and hold open means operable in the absence of cartridges in a magazine and in the breech to allow said slide to be held in the fully retracted position and simultaneouslyto release said trigger guard for limited forward and downward movement, said trigger guard being provided with means which on said movement cause said locking block to disengage from the barrel, whereby the barrel can be removed without the necessity forfu rther disassemb- ling ofthefirearm.

2. Afire arm as claimed in Claim 1, wherein forward movement of said locking block is arrested by infringement ofthe front of said block on a fixed part of the frame.

3. Afire arm as claimed in Claim 2, wherein said fixed part is a round pin and the front of said biock has a part-circular groove therein which co-operates with said pin to permit pivotal movement ofthe block about the pin.

4. Afire arm as claimed in any of Claims 1 to 3, wherein said block is provided with an upstanding transverse wing, the outer portions ofwhich are adapted to engage in recesses in the bottom ofthe side walls of the slide, whi Ist the centrai partthereofis adapted to engage in a recess in the bottom of said barrel, whereby said barrel and slide can be positively locked together and to said block.

5. Afire arm as claimed in Claim 4, wherein said trigger guard is provided with a cam surface, which co-operates with said locking blockto disengage said wing from the recesses in said slide at the end ofthe high pressure period ofthefiring cycle.

6. Afire arm as claimed in Claim4orClaim 5, wherein said hold open means comprises an inner member which is pivotable intermediate its ends in said frame, one end of said inner member being engageable in said recess in the bottom of one side wall of the slide and the other serving as a safety catch againstforward motion of said trigger guard, the pivoting motion of said inner member being such that upward movement of said one end into engagement with said recess is accompanied by downward movement ofthe other end to release said trigger guard.

7. Afire arm as claimed in Claim 6, wherein in the locking position, said other end of said inner member abuts against a stud formed thereon to prevent forward movement of the trigger guard.

8. Afire arm as claimed in Claim 6 or Claim 7, wherein pivotal movement of said hold open means to hold said slide in the fully retracted position and to free the trigger guard, is effected automatically by the magazine follower when the magazine is empty and the last cartridge in the breech chamber has been fired.

9. Afire arm as claimed in Claim 8, wherein said hold open means includes an outer member pivoting with said inner member and said hold open means pivots to an intermediate position when the magazine is empty butthe last cartridge in the breech chamber has not yet been fired, wherebythe position of said outer member affords a visual and tactile indication thatthe magazine is empty but the chamber contains a cartridge.

10. Afire arm as claimed in any one of Claims 6to 9, whererin said hold open means is provided with spring means acting against the pivotal movement into the slide holding position, said spring also acting asa return barforthetriggerbarofthefiring lock of the fire arm.

11. Afire arm as claimed in any one ofthe preceding Claims including a pin fixed in the frame and serving as a stop against rearward movement of said trigger guard.

12. Afire arm as claimed in any one ofthe preceding Claims, wherein the forward and downward movement allows the removal of a trigger pivot pin to permit removal of the trigger and trigger bar.

13. Afire arm as claimed in anyoneofthe preceding Claims, wherein downward movement of saidtriggerguard is limited by engagement of a nose on the frame in a detent on the trigger guard.

14. A self loading fire arm ofthe locked breech, short recoil pistol type substantially as hereinbefore described with reference to the drawings.