US3584533A

US3584533A - Autoloading firearm of the blowback type

Info

Publication number: US3584533A
Application number: US792694*A
Authority: US
Inventors: Harold D Allyn
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-01-21
Filing date: 1969-01-21
Publication date: 1971-06-15
Anticipated expiration: 1988-06-15

Abstract

An autoloading firearm of the blowback type free of the usual trigger spring and sear spring and operative with only two springs, a recoil spring and a hammer spring, in the entire unit not inclusive of an extractor spring and the inherent spring tension in a magazine catch.

Description

United States Patent Harold D. Allyn l0 Sumner Ave., Springfield, Mass. 01108 792,694

Jan. 21, 1969 June 15, 1971 lnventor Appl. No. Filed Patented AUTOLOADING FIREARM OF THE BLOWBACK TYPE 5 Claims, 51 Drawing Figs.

U.S. Cl 89/144, 42/25, 42/75, 89/148 lnt.Cl F4ld 11/02 Field of Search 42/69 B; 89/130- 156 References Cited UNITED STATES PATENTS 5/1916 Buckham 89/144 2,224,758 l2/l940 Brewer 89/l39 2,296,998 9/1942 Koehler... 89/150 2,356,727 8/1944 Reisina .4 89/142 2,894,346 7/1959 Smith 89/139 2,984,037 5/1961 Wilhelm.. 42/69(B) 3,236,154 2/1966 lwashita 89/142 Primary Examiner-Samuel Feinberg Assistant Examiner-Stephen C. Bentley Attorneys Kenwood Ross and Chester E. Flavin ABSTRACT: An autoloading firearm of the blowback type free of the usual trigger spring and sear spring and operative with only two springs, a recoil spring and a hammer spring, in the entire unit not inclusive of an extractor spring and the inherent spring tension in a magazine catch.

PATENTEU JUN] 5 I97! SHEET 1 0F 6 INVENTOR. HAROLD o. ALLYN ATTORNEYS.

PATENTEU JUN] 5 |97| SHEET 2 [1F 6 Em: E. n

o qn 1| I}, N V- l I II I MU A a INVEN R.

HAROLD D. LYN

ATTORNEYS.

PATENTEUJUNI 51911 3584.533

SHEET I; [1F 6 N EQE INVENTOR. HAROLD D. ALLYN BY @nwvzi @0140! m 67 mm ATTORNEYS.

PATENTEU JUN] 5 I971 SHEET 5 [IF 6 INVENTOR HAROLD o. ALLYN BY @I a/wd @914 and AUTOLOADING FIREARM OF THE BLOWBACK TYPE A primary object of the invention is to provide a semiautomatic firearm which is operable with but a pair of helical springs so arranged that a pressure differential between a fully loaded hammer spring and a preloaded recoil spring, with the hammer cocked and with the breech bolt driving forwardly to closed position, is such as to cause a sear to move forwardly along a pin which also provides spring tension for the safety, serving as both a trigger pivot pin and a scar pivot pin through the means of an elongated slot in the sear, and also so as to cause the sear to move and a bent portion thereof also moves forwardly therewith beneath a pull surface of the trigger whereby the finger portion of the trigger is biased forwardly. The hammer spring serves the function of the usual trigger spring, and the recoil spring exerts a continuous rearward pressure upon an upwardly extending portion of the sear, above the pivotal elongated slot, so as to bias upwardly a forward portion of the sear wherefor an uppermost sear point of the sear engages in a peripherally located sear notch of the hammer at the appropriate time whereby the recoil spring serves the function of the usual sear spring.

The sear is provided with an upwardly extending rearward portion and an elongated slot therebelow cooperating with a bent portion which contacts a pull surface of the trigger and, due to a longitudinal movement allowed by the elongated slot, functions as a disconnector for the firing mechanism.

Rearward pressure from a recoil spring guide, forced rearwardly by the recoil spring which serves to bias upwardly the forward portion of the sear, allows the sear point of the sear to contact the sear notch of the hammer, thereby eliminating the dictate for a separate sear spring.

Forward pressure through the sear point due to a fully loaded hammer spring causes the bent portion of the sear to contact the retaining surface of the trigger with the trigger held rearwardly and to bias the finger portion of the trigger forwardly when the trigger is released, thereby eliminating the dictate for a trigger spring.

The sear includes a stop surface to prevent unwanted sear movement and a sear block surface which provides a safety feature.

The trigger is provided with a stop surface for preventing unwanted rearward movement of the finger portion of the trigger and with a pull surface for cooperating with the bent portion of the sear.

A trigger-sear pin provides the pivoting means for both the trigger and the sear, with one extremity of the pin being coiled so as to provide a detent notch tension.

The invention comprehends, in an autoloading firearm of the blowback type, a hybrid arrangement of parts such that, with the engagement of a single assembly screw by a coin or similar object, the entire weapon including the barrel and receiver may be completely assembled or disassembled, without the use of additional tools.

As other characterizing features:

. The breech bolt and hammer and associated parts are assembled or disassembled from the forward end of the receiver, permitting a streamlining of the receiver rearward end to make it integral with the cylindrical forward end and avoiding the usual unsightly receiver midsection.

2. The trigger scar and safety are operative upon a common pivot pin which, significantly, is the only pin in the firearm.

. The trigger-sear mechanism is capable of semiautomatic fire without a trigger spring or sear spring.

4. The magazine catch and ejector are combined into a unitary component, utilizing its own inherent spring tension for magazine retention and held fast in the lower portion of the receiver by means of the magazine housing and without the usual pins or screws.

5. The magazine housing in situ by its own upper forward end portion and defines a feed ramp entering a lateral slot in the rearward barrel face, while the rearward end of the magazine housing is retained by a pair of arcuate rearwardly extending projections and engageable with the lower portion of the receiver at the rear of the magazine housing opening.

6. The assembly screw, the only screw in the operating mechanism, may be tightened so as to force the rearward end of a bedding plate rearwardly to lock the magazine housing and the magazine catch-ejector in place and render them immovable. Simultaneously a takedown lug, drawn downwardly by a takedown screw, solidly locks the barrel with respect to the receiver and the entire mechanism is locked with respect to the stock.

7. Whereas normally, in firearms of this type, only the trigger is blocked when the safety is placed in safe position, herein the safety blocks the trigger against pulling rearwardly therewith and additionally precludes unwanted vertical reciprocation of the sear.

Of the drawings:

FIG. 1 is a fragmentary sectional view, in side elevation, of the firearm in closed ready-to-fire position, showing one form of a bedding plate in association therewith;

FIG. 2 is a fragmentary view, in side elevation, partly in section, showing the FIG. 1 firearm immediately following release of the hammer by the sear;

FIG. 3 is a fragmentary sectional view, in side elevation, showing the FIG. 1 firearm at the moment of firing;

FIG. 4 is a view, similar to FIG. 3, showing the firearm in full recoil position;

FIG. 5 is a view, similar to FIG. 4, showing the firearm immediately prior to the release of the trigger forwardly;

FIG. 6 is a partial bottom plan view of the rear portion of the receiver, showing the sear block portion of an alternate form of safety in fire position;

FIG. 7 is a partial plan view, of the rear end of the receiver, showing the thumb piece of the alternate form of safety of FIG. 6 in safe position;

FIG. 8 is a partial view, in side elevation, of the rear end of the receiver, showing the sear block portion of the alternate form of safety of FIG. 6 in safe position;

FIGS. 9 and 10 are views, in rear and side elevation respectively, of the recoil spring washer;

FIG. 11 is a view, in bottom plan, of the extractor;

FIG. 12 is a view, in side elevation, of the recoil spring guide;

FIG. 13 is a view on line 13-13 ofFIG. 12;

FIG. 14 is a partial sectional view of the front portion of the breech bolt, as viewed from the top, showing the extractor and extractor spring;

FIG. 15 is a view, in rear elevation, showing the firing mechanism removed from the stock and with the trigger-sear pin in place;

FIG. 16 is a view, in section, on line 16-16 of FIG. 1, showing the trigger-sear pin retained by the stock;

FIG. 17 is a view, in section, on line 17-17 of FIG. 1;

FIG. 18 is a view in section, on line 18-18 of FIG. 2;

FIG. 19 is a view in section, on line 19-19 of FIG. 38;

FIG. 20 is a view, in section, on line 20-20 of FIG. 38;

FIGS. 21 and 22 are views, in rear and side elevation respectively, of the sear;

FIGS. 23 and 24 are views, in rear and side elevation respectively, of the magazine housing showing the preferred form of magazine housing lugs;

FIGS. 25 and 26 are views, in side and front elevation respectively, of the takedown cam;

FIGS. 27 and 28 are views, in rear and side elevation respectively, of the trigger;

FIG. 29 is a partial view, in side elevation, of the front portion of an alternate form of trigger;

. FIGS. 30 and 31 are views, in side and front elevation respectively, of the takedown lug;

FIG 32 is a view, in bottom plan, of the receiver;

FIG. 33 is a schematic view of the assembly locking means;

FIGS. 34 and 35 are views, in side and front elevation respectively, of the combination magazine catch and ejector;

FIGS. 36 and 37 are partial rear and side elevational views respectively of the magazine showing the magazine retaining lug;

FIG. 38 is a vertical longitudinal cross-sectional view of the preferred form of bedding plate and associated components;

FIGS. 39 and 40 are plan and elevational views respectively of the bedding plate of FIG. 38;

FIG. 41 is a partial plan view of the rear portion of the firearm mechanism, showing the safety;

FIG. 42 is a side elevational view of the rear portion of the mechanism, showing the safety and trigger-sear pin;

FIGS. 43 and 44 are rear and side elevational views respectively of a first alternate form of trigger and sear;

FIGS. 45 and 46 are rear and side elevational views respectively of a second alternate form of trigger and sear;

FIGS. 47 and 48 are rear and side elevational views respectively of a third alternate form of trigger and sear;

FIGS. 49 and 50 are side elevational and bottom views respectively of the safety; and

FIG. 51 is a fragmentary sectional side elevational view, partly in section, of an alternate form of lug and feed ramp of the magazine housing.

A semiautomatic firearm embodying the present invention is shown in FIG. 1 as including a stock 2, trigger guard 3, fore end 4, butt stock 6, barrel 8 and receiver 9.

Receiver 9 is shown as a tubular, single-piece, screwmachine part, fully open at its forward portion, and terminating in a streamlined pointed rearward end, but it could be of two-part construction, with a tubular forward portion and a rearward portion in the form of a casting joined thereto as by brazing.

A centrally located longitudinally extending slot in the lower portion of receiver 9 will be seen, in FIGS. 1 and 2, to accommodate a sear 10.

Another adjoining longitudinally extending slot, best seen in the bottom plan view of the receiver (FIG. 32), accommodates a trigger 11.

A laterally extending trigger-sear pin 12 is projected through suitable aligned openings in receiver 9, trigger ll, sear l0, and in a safety 13, thereby to retain the components in proper relative positions. With respect to sear and safety 13, such openings are elongated horizontally extending slots 14 and respectively.

The rear of receiver 9 is provided with a vertically disposed longitudinally extending flat face, and safety 13, positioned thereadjacent, is retained by a spiral portion 16 of trigger-sear pin 12, as shown in FIGS. 15 and 16. Spiral portion 16 provides, in springlilte manner, a detent tension for the safety and also bears upon the inner wall of stock 2 to preclude lateral movement of the trigger-sear pin.

Spiral portion 16, as shown in FIG. 41, has a free terminal in the form of a retaining bend l7 receivable in an opening 18 in safety 13. Due to elongated slot 15 in the safety, a spring tension is obtained to urge the safety forwardly and to allow a detent portion 19 of the safety to operate within vertically disposed detent slots in the rear of the receiver.

Sear 10 is best shown in FIGS. 21 and 22, trigger 11 is best shown in FIGS. 27 and 28, safety 13 is best shown in FIGS. 49 and 50, and safety 13 and trigger-sear pin 12 are best shown in FIG. 42.

If desired, receiver 9 could be provided with a vertical undercut, not shown, adjacent the forward end of its vertically disposed longitudinally extending flat portion and extending forwardly for freely accommodating the forward end of safety 13, and the safety could be provided with a forwardly extended portion for reception in the receiver undercut to maintain the front of the safety in contacting relationship with the receiver flat portion.

A forwardly extending sear block portion of safety 13, shown in FIGS. 49 and 50, is located downwardly of a thumbpiece 21 so that, with detent portion 19 of the safety in a provided left-hand or fire detent notch in receiver 9, the sear block portion is disposed adjacent the left-hand side of the scar and allows free vertical movement of its rearward end.

With detent portion 19 in a provided right-hand or safe detent notch, sear block portion 20 is interposed between the receiver horizontal flat portion and the extreme upper rear portion of sear 10 to prevent sear vertical movement and preclude gun discharge.

A protrusion between the fire and safe detent notches on the receiver allows detent portion 19 of the safety readily to be passed thereover owing to elongated slot 15 and to the resilience of a spiral coil adjacent the forward portion of the safety. A shoulder on the outboard side of each detent notch retains thumbpiece 21 within the confines of the detent notches, when the safety is thrown.

When the firearm is in uncocked position, safety 13 cannot be thrown from fire to safe position.

Safety 13 is shown, in FIGS. 2-5, in fire position, where it is incapable of being thrown to safe position as the extreme upper rear portion of sear 10 is in a rearward position to block any lateral movement of the forward end of scar block portion 20 of the safety.

When a breech bolt 22 is in closed, hammer-cocked, position, and when trigger 11 is released forwardly, as shown in FIG. 1, sear 10 is also in forward position and safety 13 is free to be moved from fire to safe position, enabling the operator thereby to ascertain the cocked or uncocked condition of a hammer 24.

Receiver 9 has a centrally located longitudinally extending front opening to allow breech bolt 22 and hammer 24 to reciprocate freely therein, whereby the rearward face of the hammer contacts a recoil surface 26 of the receiver upon termination of the recoil stroke, as shown in FIG. 4.

Rearwardly and centrally of this opening, a second opening of reduced size serves to freely accommodate a hammer spring 28 and rearwardly and centrally of this second opening, a third opening of reduced size serves to freely house a recoil spring 30 which embraces a recoil spring guide 32.

As shown in FIG. 12, recoil spring guide 32 terminates rearwardly in an enlarged portion, the front end of the enlarged portion serves as a recoil spring shoulder and its extreme rear end is rounded or pointed for contacting an upwardly extending rearward portion 34 of sear 10.

The forwardly facing surface of upwardly extending rearward portion 34 may be inclined to provide a camming action and in urging the rear end of the sear downwardly. Due to a pivoting action at trigger-sear pin 12, the sear front end is urged upwardly.

This joint camming and pivoting action enables recoil spring 30, through recoil spring guide 32, to provide an upward urging of the front end of sear 10 so as to cause a scar point to pivot in a sear notch in hammer 24.

The camming angle on the forward face of upwardly extending rearward portion 34 can be eliminated, if desired.

The forward end of recoil spring 30 seats in a recoil spring washer 36, which washer is receivable in a provided opening in the rear end of breech bolt 22.

The sides of the forward portion of recoil spring guide 32, rearwardly of a full diameter forward retaining end, are flattened to allow passage through a provided slot in recoil spring washer 36 as breech bolt 22 recoils rearwardly.

The recoil spring washer is detailed in FIGS. 9 and 10, and the recoil spring guide is detailed in FIGS. 12 and 13.

Hammer spring 28, circumscribing recoil spring 30, is wound in the opposite hand therefrom, and its front portion is nestable in a provided hammer spring opening in hammer 24. The rear portion of the hammer spring rests on a shoulder at the juncture of the hammer spring opening and the recoil spring opening in receiver 9.

An opening, of sufficient size to allow free passage of recoil spring 30 therethrough, extends forwardly from the hammer spring opening to the forward face of hammer 24, as will be seen in FIG. 1.

As shown in FIG. I, an opening in breech bolt 22 allows clearance for the forward portion of recoil spring guide 32 when breech bolt 22 is in full recoil position.

A bolt handle 38 (FIGS. 2, l8 and 19) allows manual operation of the breech bolt. A longitudinally extending bolt handle slot 40 in receiver 9 prevents breech bolt rotation during its rearward and forward travel.

A retaining notch 42 allows bolt handle 38 to be rotated upwardly, carrying breech bolt 22 therewith, and the breech bolt may be thereby retained in a rearward open position, when desired. See FIGS. 2, l8 and 32.

The firearm is shown in the closed, ready-to-fire position in FIG. 1.

In such position, the front portion of recoil spring 30, through recoil spring washer 36, pushes forwardly upon breech bolt 22 to maintain it in closed position, and the rear end of the recoil spring bears on the enlarged head of recoil spring guide 32 to push rearwardly on upwardly extending rearward portion 34 of sear 10 so as to cause the sear to pivot on trigger-sear pin 12 and to maintain the sear point of the sear in the sear notch of hammer 24, as aforementioned.

The pressure exerted by the recoil spring on the sear, owing to elongated slot 14 in the sear, would normally push the sear rearwardly along trigger-sear pin 12. However, with the sear point of the sear maintained in the sear notch of the hammer and with breech bolt 22 in forward ready-to-fire position, the recoil spring is under preload, to keep the breech bolt in closed position, and hammer spring 28 is under full load.

A greater force is exerted by the hammer spring in pushing forwardly on the hammer which is connected to the sear in the respect that the sear point of the sear is maintained in the sear notch of the hammer, all so as to overcome the weaker force of the recoil spring 30 which pushes rearwardly on the sear through sear rearward portion 34, wherefor the sear is caused to move forwardly along trigger-sear pin 12 until it is stopped when the rear wall of the elongated slot abuts the trigger-sear pin.

The finger portion of trigger l1, forwardly biased by means yet to be described, is in its forwardmost position and a bent portion 44 of scar 10 is under a pull surface 46 of the trigger. See FIG. 1.

In FIG. 2, the firearm is shown immediately following the release of the hammer by the sear a moment after the trigger has been pulled.

The sear point of scar 10 has been withdrawn from the sear notch of hammer 24 as pull surface 46 of trigger ll presses downwardly on bent portion 44 of the sear. Rearward movement of the finger portion of the trigger, following the release of the hammer by the sear, is precluded by the fact that the extreme upper rear of the trigger strikes the lower rear portion of receiver 9.

The hammer has moved slightly forwardly under the tension of the hammer spring. The scar, relieved of the forward tension exerted by the stronger fully loaded hammer spring through the sear notch of the hammer engaging the sear point of the sear, is now under a rearward pressure of the weaker preloaded recoil spring 30 through the recoil spring guide pressing upon rearward portion 34 of the sear. Thus relieved of the forward tension of the hammer spring, the sear has moved rearwardly under the rearward tension of the recoil spring and along trigger-sear pin 12 until further movement is precluded when the forward wall of the elongated slot in the sear abuts the trigger-sear pin. Bent portion 44 of the sear has moved rearwardly therewith and out of contact with the pull surface of the trigger. Meanwhile, relieved of the downward pressure exerted by the pull surface of the trigger, the sear point of the sear has been urged upwardly until the sear point has contacted the hammer periphery rearwardly of the sear notch.

Elongated slot 14 is rearward with respect to trigger-sear pin 12 and the finger portion of the trigger is in the rearmost position, being held there by the operator's finger.

In FIG. 3, the components are shown in their positions at the moment of discharge.

Hammer 24, under tension of hammer spring 28, has moved forwardly, struck a firing pin 47, and fired the cartridge. The

rear end of the hammer has cleared the sear point of the sear so that the forward end of the sear has moved upwardly until such upward movement is precluded when a fiat on the upper forward portion thereof contacts the lower cylindrical surface of receiver 9.

When the front end of sear 10 has moved upwardly after the rear end of the hammer has passed thereover, bent portion 44 of the sear has also moved upwardly into a position slightly rearwardly of a retaining notch 48 in the trigger. Elongated slot 14 in the sear has remained rearwardly with respect to trigger-sear pin 12. Hammer spring 28 and recoil spring 30 are not both in a preloaded condition. The finger portion of the trigger is now under no spring tension, there being no contact between the sear and the trigger at the forward ends thereof, and the trigger being held rearwardly by the operators finger. A slight camming angle may be placed on the forward face of bent portion 44 and a corresponding angle located on the retaining notch 48 of the trigger.

In FIG. 4, the relationship of the components in the full recoil position is shown.

Breech bolt 22 has recoiled to the rear in the conventional manner of an inertia-type gun.

Meanwhile, an extractor 50 has pulled the fired shell (not shown) from the chamber and an ejector point 51 of a magazine catch and ejector 52 has thrown it out from the ejector port 54. See FIGS. 14, 34, 35 and 38.

Breech bolt 22 and hammer 24 have been stopped in their extreme rearward positions by virtue of the rear end of the hammer striking recoil surface 26 of receiver 9.

The sear point of the sear was moved downwardly as the rear portion on the hammer passed thereover, and has then moved upwardly into the overtravelled sear notch of the hammer, the sear point being biased upwardly by fully loaded recoil spring 30, through recoil spring guide 32, as described.

As trigger 11 was pulled, elongated slot 14 in the sear has remained rearwardly with respect to trigger-sear pin 12. Bent portion 44 of the sear has remained, unchanged from the FIG. 3 position, rearwardly of retaining notch 48 in the trigger. Hammer spring 28 and recoil spring 30 are both in fully loaded condition. The finger portion of the trigger is held rearwardly but remains under no spring tension. If the operators finger were removed from the trigger, the position of the trigger would remain unchanged or, if pushed forwardly, would remain in forward position, a condition which prevails, as previously stated, because bent portion 44 of the sear does not contact the forward part of the trigger.

At the completion of its rearward recoil stroke, breech bolt 22, under tension of recoil spring 30, and hammer 24, under tension of hammer spring 28, move forwardly unisonly until the sear notch of the hammer engages the sear point of scar l0. Thereupon, the sear retains the hammer, and the breech bolt continues forwardly under the recoil spring tension, through recoil spring washer 36. Meanwhile sear is moving forwardly with the hammer which is under the forward tension of the fully loaded hammer spring. The hammer moves forwardly and pulls the sear forwardly therewith a distance equal to the clearance between the front of bent portion 44 of the sear and retaining notch 48 in the trigger, all being accomplished by the fact that the sear point of the sear is engaged in the sear notch of the hammer and overcomes the weaker partly loaded recoil spring pushing rearwardly on the sear through the rearwardly enlarged portion of the recoil spring guide bearing on the upwardly extending portion 34 on the sear.

In FIG. 5, the firearm is shown immediately prior to the release of the trigger forwardly.

At this point, trigger sear pin 12 is disposed between the rearward and forward walls of the elongated slot 14 in the sear, the breech bolt having closed and being under tension of the recoil spring under preload through the recoil ,spring washer. The hammer has been cocked and the finger portion of the trigger is being held in rearward position by the operators finger.

During closing movement, the cartridge has been stripped from the magazine and loaded into the chamber in conventional manner.

The forward end of bent portion 44 of the sear is in contact with retaining notch 48 of the trigger at a point below the trigger pivot point at trigger-sear pin 12. Forward pressure exerted by the fully loaded hammer spring, through the sear notch of the hammer and the sear point of the sear upon retaining notch 48 of the trigger, biases the trigger in a counterclockwise direction overcoming the weaker preloaded recoil spring, as the sear moves forwardly, so as to urge, when the operator releases the trigger, the front end of the trigger upwardly and the finger portion of the trigger forwardly.

Retaining notch 48 has moved upwardly to a point where the notch no longer holds the sear in rearward position, wherefor the sear moves forwardly and the bent portion thereof moves under pull surface 46 of the trigger until further forward movement is precluded when the rear wall of the elongated slot abuts trigger-sear pin 12.

Further forward movement of the finger portion of the trigger is precluded when an upper horizontal surface 56 of the trigger contacts the lower outside portion of the receiver.

The components again assume the FIG. 1 position, with elongated slot 14 being forwardly with respect to trigger-sear pin 12, bent portion 44 of the sear being under pull surface 46 ofthe trigger, the hammer being cocked, the breech bolt being in closed position, and the finger portion of the trigger being in forwardmost position so that, if again pulled, the firearm will discharge.

As sear l slides along trigger-sear pin 12, the sear is stopped from further longitudinal movement at the extremities of its travel by the respective end walls of the elongated slot.

With reference to FIGS. 34 and 35, magazine catch and ejector 52 is provided in the form ofa stamping with its main body being twisted so that its lower part, is normal to the plane of its upper part. The extreme lower portion consists of a magazine retaining surface 66 and a thumbpiece 68. A bend in the top of the magazine catch and ejector, as shown in FIGS. 18 and 35, offsets the upper portion thereof from the centerline of the receiver so as to align adjacent the right-hand side of a left-hand (as viewed from the rear) magazine clearance slot 69 of breech bolt 22, wherefor an ejector point 51 serves as an ejector.

The magazine catch and ejector is extendable through a centrally located longitudinally extending slot in the lower portion of the receiver, just rearwardly of an opening for admitting a magazine housing 70.

Two guide ears may be formed forwardly from the lower portion of the magazine catch and ejector for freely embracing the lower rear outer surfaces of the magazine housing in manner to prevent lateral movement of the lower portion of the magazine catch.

The magazine catch and ejector utilizes an inherent spring tension to retain a magazine 72 and is assembled under preload whereby forward pressure is exerted by the lower forward portion of the catch on the lower rear portion of the magazine housing. Magazine retaining surface 66 overhangs the rear wall of magazine housing 70 and extends under the rear portion thereof.

Magazine 72, shown in FIGS. 36 and 37 and observed to be of conventional design, is pushed upward into the magazine housing, the forward surface of thumbpiece 68 is cammed rearwardly, when contacted by a lug 73 on the backwall of the magazine, and remains in a rearward position until the magazine is fully seated in the magazine housing, at which time the magazine catch moves forwardly by means of its inherent spring tension and magazine retaining surface 66 moves underneath the lug and retains the magazine in place.

Rearward pressure of the operators thumb on thumbpiece 68 enables the magazine to be withdrawn from the magazine housing. The vertically extending lateral portion of the magazine catch, which provides spring tension thereto, may be hollowed, as shown, to give greater resilience.

Magazine housing 70, in the form of a rectangular downwardly extending hollow member, is provided with retaining means welded or otherwise secured to its upper front and rear outside surfaces.

As shown in FIGS. 23 and 24, an upper rearwardly extending arcuate lug on the magazine housing embraces the lower inside surface of the receiver and a lower rearwardly extending arcuate lug embraces the lower outside surface of the receiver, as shown in FIG. 1 and serves to prevent vertical movement of the rear of the housing. The lower lug may be omitted, if desired.

A feed ramp portion 74, for guiding the cartridges from the magazine into the chamber, extends from the upper front surface of the housing. A lug portion 75, forwardly of the feed ramp portion and integral therewith, is receivable in a laterally extending opening in the rear face of the barrel below the chamber, thereby preventing vertical movement of the front end thereof. Lateral movement of the magazine housing is prevented by the upper outside walls of the housing contacting the inner vertical longitudinal surfaces of the magazine opening in the lower portion of the receiver.

Rearward pressure from the forward portion of an opening in a bedding plate 76, for admitting the passage of magazine housing 70 therethrough, firmly locks the magazine housing and ejector in place upon the tightening ofa take down screw 77.

Firing pin 47, preferentially a stamping, rests in a centrally located opening in the upper portion of the breech bolt and a rearwardly located downwardly extending retaining lug is disposed in an opening of sufficient length to allow necessary longitudinal movement.

Vertical movement of the firing pin is prevented by contact of its lower portion with the lower surface of a firing pin opening in the breech bolt and by contact of its upper portion with the upper inside surface of the receiver.

The front of the firing pin is offset downwardly to allow the front end of the pin to contact the cartridge primer. See FIGS. 1 and 19.

A longitudinally extending spring (not shown) may be provided to retain the firing pin in a rearward position, when out of contact with the hammer.

Proper clearance is maintained at the lower forward end of the breech bolt to clear the top portion of the magazine and the ejector. See FIG. 19.

With reference to FIG. 14, an extractor 50 is shown as being formed of round stock, and bent in the form of a U with the front end slabbed off at an angle to form the extractor hook. The extractor is retained in place by a flat extractor spring 79 biased downwardly on the rear end of a U-bend in the extractor.

To remove the extractor from the breech bolt, the forwardly and outwardly extending front end of the extractor spring may be lifted outward with a thumb nail so that the spring may be pulled forwardly from its opening in the breech bolt. Thereafter, the extractor may be lifted laterally from the extractor opening in the breech bolt.

The upper portion ofa takedown lug 81 (shown in FIGS. 30 and 31) extends laterally through a dovetailed opening in the rear lower portion of the barrel and through a mating clearance opening in the forward lower portion of the receiver. A threaded vertical opening in the lower portion of the takedown lug accepts the upwardly extending takedown screw 77, which passes through an opening in the lower portion of a Ushaped cam lock 84, the bottom of which is adjacent bedding plate 76.

The preferred form of bedding plate and associated components may best be observed in FIGS. 20 and 38, with the bedding plate per se being shown in FIGS. 39 and 40.

Laterally extending cam surfaces 86 on the upper ends of cam lock 84 bear on mating cam surfaces 87 on the lower front portion of the receiver.

An escutcheon 88, bedded in the lower portion of the stock, accepts takedown screw 77 therethrough. The portion of the takedown screw within the escutcheon also serves as a recoil lug.

Bedding plate 76, a longitudinally extending member, is U- shaped in cross section. A cam surface 89 on the bedding plate urges it rearwardly, when contacted by the lower portion of the cam lock 84, whereby the forward portion of the bifurcation of the bedding plate bears against the forward portion of the magazine housing add when the bedding plate is urged rearwardly, as the takedown lug is being pulled downwardly by the takedown screw. The opening in the bedding plate, the takedown screw passing therethrough, is elongated to allow longitudinal movement of the bedding plate. See FIG. 39.

A lower forward flat portion 90 of the bedding plate bears on a complementary surface 92 of fore end 4 that acts as a front bedding surface. A metal or plastic insert (not shown) may be permanently attached or removable, and may be placed on bedding surface 92 of the fore end to prevent wear. See FIG. 38.

The firearm assembly and the locking action of the bedding plate will now be described, bearing in mind the schematic showing of the assembly locking means in FIG. 33.

Safety 13 is placed adjacent the vertical flat on the rear of the receiver with detent portion 19 of the safety placed in the fire detent. The trigger and sear are placed in their respective slots. The elongated openings in the safety and scar and the circular opening in the trigger are then aligned with the lateral opening in the receiver for reception therethrough of the straight portion of trigger-sear pin 12.

Retaining bend 17 of the trigger-sear pin is pulled rearwardly under tension and placed in opening 18 in the safety.

Recoil spring guide 32 is placed within the coils of recoil spring 30 and the spring abutting the enlarged rear portion of the recoil spring guide is compressed upon the shaft thereof.

The slotted portion of recoil spring washer 36, with its concave side facing rearwardly, is assembled upon the rectangular portion of the recoil spring guide. The spring is released to allow the foremost coils to bed within the concave portion of the washer and the forward circular portion of the recoil spring guide retains the spring and washer upon the shaft of the recoil spring guide.

An end of hammer spring 28 is placed in the hammer spring opening in the rear end of hammer 24. With the hammer spring to the rear, hammer and hammer spring are assembled in receiver from the front end, the free end of the hammer spring being receivable within the hammer spring opening in the receiver.

The recoil spring, with the recoil spring washer forwardly, is assembled through the recoil spring opening in the front end of the hammer and is passed therethrough until rearward travel is terminated by the rear face of the recoil spring washer contacting the forward end ofthe hammer.

Should the recoil spring washer inadvertently become lost, the recoil spring guide and recoil spring and hammer spring may still be assembled in the receiver but buckling of the recoil spring must be avoided.

Extractor 50, with its hook portion forward, is placed laterally in the extractor opening in the breech bolt. The flat end of extractor spring 79 is pushed rearwardly into the provided longitudinally extending opening in the breech bolt until further movement is precluded by the rear end of the spring striking the end of the opening, by which time the forward end of the spring will have passed rearwardly over the mid or high portion of the inverted U of the extractor thereby retaining the spring in place and providing lateral or inward bias of the extractor.

Firing pin 47 is then placed in the longitudinally extending slot in the uppermost portion of breech bolt 22.

The breech bolt, with extractor forwardly, is pushed rearwardly into the front of the receiver. The enlarged portion of the recoil spring guide clearance opening in the rear end of the breech bolt aligns with the forward end of the recoil spring guide and the forward portion of recoil spring washer 36 nests itself therein. Further rearward movement of the breech bolt enables the bolt handle opening in the breech bolt to be aligned with ejector port 54 whereby bolt handle 38 may be placed in the proper opening in the breech bolt.

Ejector port 54 being of greater width than the diameter of the bolt retaining portion 93, the bolt handle may be assembled therethrough and into the appropriate opening in the breech bolt whereby the bolt retaining portion may be fully seated in the concentric large diameter opening in the side of the breech bolt.

With the safety in fire position, the bolt handle is pulled to the rear, carrying the breech bolt therewith, and the neck portion of the bolt handle is caused to enter bolt handle slot 40 in the receiver.

Thereafter, the bolt handle is pulled further rearwardly until its neck portion is aligned with bolt handle retaining notch 42. Thereupon, the bolt handle is pulled upwardly to rotate the breech bolt, thereby retaining the breech bolt in a rearward position.

When the barrel is in place, the bolt handle cannot move forwardly to a point where it enters the ejector port and is therefore retained in place.

The upper portion of the magazine catch and ejector, just below the offset bend, is pushed rearwardly into the longitudinally extending opening in the lower portion of the receiver, just rearwardly of the opening for receiving the magazine housing. Rearward movement is precluded when the rear portion of the catch within the slot strikes the rear end of the slot.

Upward movement of the front end of the magazine catch and ejector is precluded by the lower portion of notch 94 in the upper front end of the catch bearing on the under side of the lower rearwardly extending arcuate lug on the upper rear portion of the magazine housing.

If the lower arcuate lug is omitted, notch 94 would be moved upwardly, replacing an opening in the magazine catch and ejector that provides a clearance for the upper arcuate lug (FIGS. 34 and 38). The lower portion of notch 94, in its new location, will then contact the underside of the upper arcuate lug to prevent unwanted upward movement of the magazine catch and ejector.

Downward movement of the catch is prevented by the lower portion of the offset bend bearing on the lower inside surface of the receiver, as shown in F [G 18, and upward movement of the rear portion is precluded by a rearwardly extending portion bearing on the lower outside surface of the receiver. See FIG. 1.

The extreme front end of the upper portion extends slightly forwardly into the magazine housing opening so as to be contacted by the rear end of magazine housing 70 at the final tightening of the takedown screw.

The upper portion of the magazine housing is pushed upwardly and forwardly into the appropriate opening in the lower portion of the receiver. The front end is dropped slightly while the magazine housing is moved rearwardly and the two rearwardly extending arcuate lugs are caused to embrace the lower portion of the receiver at the rearmost end of the housing opening therein.

The rear end of the barrel is placed in the opening in the front end of the receiver and pushed rearwardly and the laterally extending opening in the rear of the barrel just below the chamber, is caused to be aligned with lug portion 75 of feed ramp portion 74 attached to magazine housing 70. The lug portion is of such size and configuration as to fit snugly into the laterally extending slot in the barrel.

Continuing the barrel movement rearwardly in the receiver causes lug portion 75 to fully enter the laterally extending slot in the barrel and the dovetailed slot in the barrel to be aligned with an appropriate opening in the forward lower portion of the receiver.

The upper male dovetailed portion of takedown lug 81 is pushed laterally through the complimentary opening in the lower front end of the receiver and into the dovetailed slot in the barrel, thereby retaining the barrel loosely in the receiver.

The opening is of sufficient size to provide a slight all around clearance in the receiver for the dovetail portion of the takedown lug.

Cam lock 84 is pushed upwardly to embrace the downwardly extending portion of the takedown lug. The upwardly extending arms of the cam lock are bent slightly inwardly to provide sufficient tension to enable the cam lock to be retained on the takedown lug during preliminary assembly.

The bedding plate, with its bifurcated portion to the rear, and with its elongated slot downwardly, is pushed rearwardly over, and embraces, the assembled takedown lug and cam lock. Continuing rearwardly the bifurcated portion is caused to embrace the magazine housing and is pushed over magazine housing lugs 95, which are attached to or made integral with magazine housing 70, until stopped by the forward end of the bifurcation of the bedding plate contacting the forward surface of the magazine housing.

To assemble the mechanism to the stock, the barrel and receiver, with all parts attached thereto including the rear bifurcated portion of preferred bedding plate 76 resting on magazine housing lugs 95 and inside cam surface 89 adjacent a curved cam portion 97 of cam lock 84, are grasped with the left hand. The thumb and fingers hold the forward portion of the bedding plate upwardly toward the barrel. With the stock in the right hand, the lower portions of the assembled mechanism are placed in appropriate openings in the stock. The takedown screw is' pushed upwardly through the escutcheon and the elongated opening in the bedding plate and through the circular opening in the cam lock and is screwed by hand into the threaded opening in the takedown lug whereby, when the takedown screw is further tightened, locking action initiates.

The tightening of takedown screw 77 with a large coin or the like pulls takedown lug 81 downwardly as the head of the takedown screw presses upwardly on the bottom surface of the stock through the escutcheon. See FIGS. 33 and 38. The upper dovetail portion of takedown lug 81 bears upon the complimentary dovetail in the lower rear end of the barrel and centers the takedown lug in relation to the dovetail slot as the barrelis pulled downwardly and the bottom of the barrel contacts the inside bottom of the front of the receiver.

The receiver, with the barrel attached, continues downwardly until the rear bottom portion thereof contacts rear receiver bedding surface 98 of the stock and the curved cam portion 97 of cam lock 84 contacts cam surface 89 of bedding plate 76, forward portion 90 of which now contacts fore end bedding surface 92 and the rear end thereof contacts the top surfaces of magazine housing lugs 95. Thereupon as the rear end of the receiver is pulled downwardly, upper cam surfaces 86 of cam lock 84 is forced into firm contact with complimentary receiver cam surface 87 centering the barrel longitudinally in the receiver in relation to cam lock 84 and also in relation to the takedown lug.

Meanwhile, additional downward pressure is applied by the rear bifurcated portion of the bedding plate on the top surfaces of magazine housing lugs 95 pulling the rear end of the receiver downwardly and firmly against rear bedding surface 98 of the stock. Curved cam surface 97 of the rear lower portion of cam lock 84 applies pressure to cam surface 89 on bedding plate 76 forcing it rearwardly and downwardly therewith and causing the bifurcated portion to press rearwardly on the forward wall of the magazine housing forcing the rear wall thereof against the forwardly protruding front portion of magazine catch and ejector 52, rearward movement of same being terminated by the rear portion of the catch that is within the slot in the bottom of the receiver striking the rearmost wall of aforesaid slot.

As the magazine housing is being forced rearwardly by cam 97 on cam lock 84, it is also being forced downwardly through magazine housing lugs 95, by the rear end of bedding plate 76, as previously described.

The arcuate lugs on the rear portion of the magazine housing embrace the lower wall of the receiver. Lug portion 75 on the feed ramp of the magazine housing; within the laterally extending slot on the rear face of the barrel, limits downward movement of the magazine housing. The magazine housing and the magazine catch and ejector are locked in place thereby and the lower rear end of the receiver is bedded on receiver bedding surface 98 in the stock and lower front end of bedding plate 76 bedded on front bedding surface 92 of the stock.

Final tightening of the takedown screw finishes the locking action by pulling the receiver downwardly thereby increasing pressures previously described and further securely locking the barrel in the receiver, the magazine housing in the receiver, the magazine catch in the receiver and the barrel receiver and related parts securely in the stock. The barrel is free floating in the fore end.

In assembly locking, the final tightening of the assembling screw centers the barrel longitudinally in respect to the takedown lug, centers the barrel and takedown lug longitudinally in respect to the receiver by means of the cam surfaces 86 and 87, centers the barrel laterally in the receiver, locks the barrel in place in the receiver, locks the takedown lug in the barrel, cams the bedding plate rearwardly, locks the magazine catch and ejector in the receiver, locks rear end of the receiver on the rear bedding surface of the stock, locks the front end of the bedding plate on the front bedding surface of the stock, locks the rear end of the bedding plate down upon the ears of the magazine housing, locks the upper portion of the magazine housing in the receiver, locks the head of the assembly (takedown) screw (through the escutcheon) to the bottom of the stock, hence locking the entire firearm mechanism securely in the stock.

In the next few paragraphs, we interject a few possible modifications which may be incorporated into the mechanism, all without defeating the primary purpose or spirit of the invention.

In order to prevent undue stress upon the trigger-sear pin by the kinetic energy imparted thereto by the stoppage of the sear, the elongated slot may be lengthened and the sear may be configured so as to be caused to strike the rear of the recoil spring bore in the receiver prior to the contacting of the front wall ofthe slot.

Additionally, forward movement of the sear may be arrested by a forwardmost portion of the sear being caused to abut the forward wall of the sear opening in the lower rear portion of the receiver.

An alternate form of trigger 11a is shown in FIG. 29 wherein a hook may be provided so that the upper inside portion 102 of the hook may replace upper horizontal surface 56 of the trigger as the means for arresting unwanted forward movement of the finger portion of the trigger.

In FIGS. 68, an alternate form of safety is shown.

Referring first to FIG. 6, the rear portion of receiver 9 is shown in bottom plan view with the modified safety in fire position, the finger portion of the trigger held to the rear and the mechanism in the full recoil position as shown in FIG. 4.

Here the safety has been combined with a modified form of trigger-sear pin 12a, the pin having a safety portion 13a which includes a sear block portion 20a and a thumb piece portion 210 aligned thereabove. A loop replaces spiral 16 of the first described trigger-sear pin 12 and supplies the desired forward detent tension. In such modification, trigger-sear pin 12a extends through receiver 9 in a manner similar to the preferred form of trigger-sear pin and the vertically disposed longitudinally extending flat portion on the rear end of the receiver may be eliminated accordingly.

Thumb piece portion 21a is shown in safe position in FIG. 7 and sear block portion 20a is shown in safe position in FIG. 8 wherein the mechanism is in the bolt closed-hammer cocked position as shown in FIG. 1.

Three alternate trigger and sear combinations are now considered, all whereby the hammer (not shown), sear point, recoil spring guide (not shown), hammer spring (not shown), and recoil spring (not shown), may be held in the same relative hammer-cocked positions as in the case of the preferred trigger and sear combination of FIG. 1.

In the first alternate form, FIGS. 43 and 44, shown in the cocked, ready-to-fire position, bent portion 44 of the preferred sear is eliminated and replaced by a bent portion 44a on a trigger 11b and is disposed rearwardly of a triggersear pin 12. Pulling rearwardly on the trigger forces the rear end of a sear a upwardly and the sear point thereof downwardly to discharge the firearm. Subsequent operation is similar to that described for the preferred form of trigger and sear.

In the second alternate form, FIGS. 45 and 46, shown in the cocked, ready-to-fire position, bent portion 44 of the preferred sear is replaced by a bent portion 44b of a trigger 11c and located forwardly of trigger-sear pin 12. Pulling rearwardly on the trigger pulls downwardly on the sear point of sear 10b to discharge the firearm. Resultant semiautomatic operations are very similar to those produced by the preferred form of trigger and sear.

In the third alternate form, FIGS. 47 and 48, shown in the cocked, ready-to-fire position, a trigger 11d and sear 100 are similar to those shown in FIGS. 43 and 44 in that the bent portion 440 is disposed rearwardly of trigger-sear pin 12 but differs therefrom in that the bent portion originates from the sear. Thereafter, the functions are very similar to those of the preferred form of trigger and sear.

In the preferred form of trigger and sear, as shown in FIGS. 1-5, bent portion 44 of the sear originates from the forward portion of the sear and the pull surface is on the forward portion of the trigger, both being forwardly of the trigger-sear pin.

In FIGS. 43 and 44a, the bent portion 44 originates from the trigger and also serves as the pull surface 46. The pivot is forwardly of the bent portion and the pull surface.

In FIGS. 45 and 46, the bent portion and pull surface also originate from the trigger but are forwardly of the trigger-sear pm.

In FIGS. 47 and 48, the bent portion and pull surface are on the sear and trigger respectively as in the preferred version but are rearwardly of the trigger-sear pin.

In FIG. 51, an alternate form of feed ramp 74a of the magazine housing is illustrated with a lug portion 75a which bears on the lower inside surface of the receiver underneath a slabbed off portion of the barrel instead of being inserted in a lateral slot in the rear of the barrel underneath the chamber.

In FIG. I is shown an alternate U-shaped bedding plate 760 operable somewhat similarly to the preferred form of bedding plate, whereby the opening for the takedown screw allows passage therethrough and provision is made for longitudinal movement of the bedding plate. The forward surface of the bifurcation on the lower rear end of the bedding plate does not contact the front face of the magazine housing but cam surfaces on the lower rear end of the rear bifurcated portion contact the upper front portions of alternate magazine housing lugs 950 which are at a corresponding camming angle. The space between the front end of the bedding plate and the vertical surface inside the fore end, as in FIG. 38, is omitted and the front end of the bedding plate contacts the said vertical surface.

Alternate bedding plate 76a is forced downwardly in a manner similar to preferred bedding plate 76, due to the lower portion of cam lock 84 contacting the lower inside surface of the bedding plate whereby it forces the magazine housing rearwardly, while pulling it downwardly, due to the camming action of the angular portion on the lower rear end of the alternate bedding plate contacting the angle on the front cam surface of alternate magazine housing lugs a, so as to lock the parts in place in a manner similar to the operation of the preferred bedding plate.

If desired, the cam surfaces on alternate magazine housing lugs and bedding plate, 95a and 760 respectively, as well as cam surface 89 on the bedding plate, as shown in FIGS. 1 and 38, may be omitted and a cam surface on the lower front end of the bedding plate, replacing the lower forward flat portion 90, and mating with a corresponding cam surface on the inside of the fore end (not shown), may be substituted therefor. In such case, the forward bottom portion of the bedding plate would not bottom on the flat stock bedding surface 92 of the fore end. The elongated slot, for the takedown screw to pass therethrough, as shown in FIG. 39, would be retained.

Also in FIG. 1, an alternate form of stamped cam lock 84a is shown in FIG. 1.

I claim:

I. In a semiautomatic firearm, the combination comprising:

a hollow receiver,

a breech bolt reciprocable in the receiver towards and away from a firing position,

a firing pin disposed at the forward end of the breech bolt,

a cockable hammer having a scar notch,

a loadable helical hammer spring,

a preloadable helical recoil spring,

a trigger having a pull surface,

a slotted sear having an offset portion directly cooperant with the pull surface of the trigger and having an upwardly extending sear notch,

a trigger-sear pin receivable in the slot of the sear for the pivoting in unison of the trigger and sear,

a safety for locking the sear against unwanted movement,

the slot of the sear allowing horizontal reciprocation of the sear with reference to the trigger-sear pin for functioning as a disconnector, the hammer spring under full load and the recoil spring under preload offering a pressure differential therebetween such that, with the hammer cocked and the breech bolt moving toward forward closed position, the sear is moved forwardly along the trigger-sear pin and the offset of the sear contacts the pull surface of the trigger for urging the trigger forwardly for the functioning of the hammer spring in the triggering of the trigger as the recoil spring exerts a continual rearward pressure on the sear for biasing the sear upwardly into position whereby the sear engages the sear notch of the hammer and the recoil spring functions as a sear spring.

2. In the firearm of claim 1, including a recoil spring guide for motivation rearwardly by the recoil spring and the pressurization of the sear and the biasing of the forward portion of the sear upwardly for the interengagement of the sear point of the sear and the sear notch of the hammer.

3. In the firearm of claim 1, with forward pressure through the hammer spring allowing the offset of the sear to contact the retaining surface of the trigger and the forward biasing of the finger portion of the trigger.

4. In the firearm of claim 1, the sear being provided with a stop surface for preventing unwanted sear movement and a sear block surface for providing a safety means.

5. In a firearm of claim 1 including a trigger with a stop surface and a pull surface cooperant with the offset of the sear and the stop surface to prevent unwanted rearward movement of the finger portion thereof.

Claims

1. In a semiautomatic firearm, the combination comprising: a hollow receiver, a breech bolt reciprocable in the receiver towards and away from a firing position, a firing pin disposed at the forward end of the breech bolt, a cockable hammer having a sear notch, a loadable helical hammer spring, a preloadable helical recoil spring, a trigger having a pull surface, a slotted sear having an offset portion directly cooperant with the pull surface of the trigger and having an upwardly extending sear notch, a trigger-sear pin receivable in the slot of the sear for the pivoting in unison of the trigger and sear, a safety for locking the sear against unwanted movement, the slot of the sear allowing horizontal reciprocation of the sear with reference to the trigger-sear pin for functioning as a disconnector, the hammer spring under full load and the recoil spring under preload offering a pressure differential therebetween such that, with the hammer cocked and the breech bolt moving toward forward closed position, the sear is moved forwardly along the trigger-sear pin and the offset of the sear contacts the pull surface of the trigger for urging the trigger forwardly for the functioning of the hammer spring in the triggering of the trigger as the recoil spring exerts a continual rearward pressure on the sear for biasing the sear upwardly into position whereby the sear engages the sear notch of the hammer and the recoil spring functions as a sear spring.