US2710477A

US2710477A - Unitary rammer-ejector for firearms

Info

Publication number: US2710477A
Application number: US331755A
Authority: US
Inventors: Clarence E Simpson
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-01-16
Filing date: 1953-01-16
Publication date: 1955-06-14
Anticipated expiration: 1972-06-14

Description

June 14, 1955 c. E. SIMPSON UNITARY RAMMER-EJECTOR FOR FIREARMS 2 Sheets-Sheet l Filed Jan. 16, 1953 HTTOENEYS June 14, 1955 c. E. slMPsoN 2,710,477

UNITARY RAMMER'EJECTOR FOR FIREARMS Filed Jan. 16, 1953 2 Sheets-Sheet 2 iig-EL TTOQNEYS 2,710,477 Patented .lune 14, 1955 Las! UNHTARY RAMMER-EJECTR FR FIREARMS Clarence E. Simpson, Wilbraharn, Mass., assigner to the United States of America as represented by the Secretary of the Army Application Sanitary 16, 1953, Serial No. 331,755

S Claims. (Cl. i2- 25) (Granted under Title 35, U. S. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.

This invention relates to automatic firearms having a longitudinally reciprocating bolt and relates more particularly to cartridge feeding and ejecting mechanisms therefor.

lt is an object of this invention to provide a simple, unitary ramming and ejecting means for firearms wherein the cartridges are fed from above and ejected below the bolt to obtain a compact firearm.

A specific object of this invention is to provide a means for electing the tired cartridge cases at a point prior to the completion of the recoil stroke of the bolt.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings in which:

Fig. l is a fragmentary longitudinal sectional View of a firearm showing the position assumed by the mechanism of this invention in the act of stripping a cartridge 'from the cartridge belt during counter-recoil of the bolt;

Fig. 2 is a View similar to Fig. 1, but showing the position of the rammer-ejeetor mechanism with the bolt in full recoil position;

Fig. 3 is a perspective view of the rammer-ejector mechanism of this invention;

Fig. 4 is a fragmentary top view of a lire-arm bolt showing the rammer-ejector mechanism incorporated therein;

Fig. 5 is a View similar to Fig. 4 but with the rammerejector mechanism removed;

Fig. 6 is a cross-sectional View taken along line 6--6 of Fig. 5; and

Fig. 7 is a front view partly in section of the rearm stock showing the bolt fully recoiled therein.

Referring to the drawings, there is illustrated a firearm having a tubular receiver 12 to the rear end of which is secured a tubular member 13 which extends rearwardly Slt) to the form the rear end of the receiver and also the stock of the firearm. A bolt 14 is arranged to reciprocate longitudinally along suitable ways provided in receiver 12 and in tubular member 13. Bolt 14 essentially com prises a body member 16 and a rectangular head member 15 slidably mounted in the forward end thereof. Body member 16 is provided with arcuate sides, which slidably engage the interior wall of tubular member 13, and a rectangular top surface 17, which slidably engages a similar rectangular surface 1S provided on the bottom of a guide member 19 lixedly secured to the upper interior surface of tubular member 13.

Secured within the forward portion of receiver 12 is a barrel extension 2i), which receives the breech end of a conventionally chambered barrel 21. A substantially rectangular channel 22 of the same size as bolt head member 15 is provided longitudinally in barrel extension to permit abutment of bolt head member 15 with the breech end of barrel 21. A ramp portion 28, having a purpose to be later explained, extends downwardly and forwardly from the upper rear face of barrel extension 20 to channel 22.

Pivctally hinged to the upper forward portion of receiver 12, is a cover member 23 in which there is incorporated a sprocket type feeding mechanism 24, fully described and explained in copending patent application, Serial No. 317,605, led October 29, 1952, which advances cartridges 39 held by a disintegrating link belt to a feedway 26 in the upper portion of receiver 12. Provided centrally in feedway 26 is a slot or opening 27 l'iaving forwardly and outwardly projecting sides which guide cartridge 3d into the interior of receiver 12. A cartridge depressor member 29, such as is described in the first mentioned copending patent application, directs cartridge downwardly through slot 27 while being rammed forwardly, in a manner to be explained later.

Provided in the bottom portion of receiver 12, rearwardly adjacent barrel extension 20, is an ejection port 32 for tired cartridge cases. A trigger housing 33, containing a conventional trigger mechanism 43, is assembled to receiver 12 adjacent the rearward end of ejection port 32.

A longitudinal ring pin 35 is mounted in the forward end of bolt body member 16 and slidably projects through a longitudinal, axial hole provided in bolt head member 15. A cylindrical recess 36 is provided in the forward face of bolt head member 15 to receive the base of cartridge 39 and is so arranged that the forward end of tiring pin 35 projects centrally therein to lire a chambered cartridge 30 when bolt 14 goes into battery position. The periphery of cartridge recess 36 is undercut to receive the rim around the base of cartridge 30 formed by extractor groove 4S. Provided in the lower side of bolt head member 15 is an extractor 37 the forward end of which is spring-biased upwardly, enabling a cartridge engaging lug 34 thereon to securely engage extractor groove 48.

On the upper side of bolt head member 15 there is provided a longitudinal rectangular slot 3S the sides of which are in alignment with the sides of a similar rectangular slot 39 provided longitudinally along the length of top portion 17 of bolt body member 16. The rearward portion of slot 3S is undercut to form a T-slot 41 having a purpose which will presently appear. The forward portion of slot 38 is provided with a stepped-up bottom portion in which there is arranged a longitudinal rectangular groove 42. In the forward end of rectangular groove 42 there is provided a notch 44 which slopes forwardly and downwardly to communicate with cylindrical recess 36. A rectangular, dove-t`ailed slot 45 is provided in the top portion of bolt head member 15, transversely intersecting Slot 38, to accommodate a mating substantially rectangular retainer-stop 46.

Accommodated in bolt head member 15, as hereinafter described, is a rammerejector mechanism 50 which is preferably fabricated from a single piece of steel of such type that substantial spring resilience may be induced therein. Kammer-ejector essentially comprises a mounting portion 51, from which there forwardly extends a rectangular rammer portion S2, and an arched ejector portion 53.

Mounting portion 51 is substantially rectangular with the bottom surface formed by a rectangular under-surface 59 which slopes downwardly and forwardly and a similar surface 60 which extends contiguously forwardly, and upwardly therefrom. The junction of undersurface portions 59 and 66 forms a pivotal point 61. Projecting from each side of mounting portion 51 is a substantially diamond shaped lug 62, the bottom surfaces of which are integral with

undersurfaces

59 and 60 and the top surfaces form a pivotal point 63 directly above pivotal point 61. The union of lugs 62 with mounting portion 51 forms a T- shaped structure which is engageable with T-slot 41 in bolt head member 15 and slidably secures rammer-ejector 50 thereto. Provided in the top of mounting member 51 is a rectangular notch S8 through which retainer-stop 46 passes to provide limited longitudinal reciprocation of rammer-ejector 5t) in bolt head member 15.

Kammer-portion 52 is arranged parallel with front undersurface portion 60 of mounting portion 51 and is engageable with rectangular slot 38.. The forward end of rammer portion 52 projects beyond the forward face of bolt head member 15 and the bottom side thereof is providedwith a transverse arcuate recess 54, the curved portion of which completes the periphery of cylindrical recess 36 when rammer portion 52 is fully engaged in rectangular slot 38.

Ejector portion 53 extends from mounting portion 50 below rammer portion 52, with the forward portion resiliently engaging rectangular groove 42. The forward end of ejector portion 53 is provided with a downwardly depending triangular lug 56 which slidably engages triangular notch 44 in the forward end of rectangular groove 42 when rammer-ejector 51) is in its rearmost position relative to bolt head member 15.

The resilient engagement of ejector portion 53 with rectangular groove 42 pivots the forward end of rammerejector 50 upwardly on

pivotal points

61 and 63 to bring rear undersurface 59 into engagement with the lower side of T-slot 41 and causes rammer portion 52 to project angularly upward from bolt head member 15.

When rammer portion 52 is pressed downwardly by external pressure into rectangular slot 38 against the bias of ejector portion 53, in a manner to be later described, rammer-ejector 50 rocks on

pivotal points

61 and 63 to engage forward undersurface portion 60 with the bottom of T-slot 41. When rammer portion 52 is pressed into rectangular slot 38 ejector portion 53 is simultaneously engaged in rectangular groove 42.

A longitudinal rectangular channel 67 having a bottom open portion of narrower width extends rearwardly into guide member 19 from the forward end thereof and is arranged in alignment with rectangular slot 39 in bolt body member 16. Accommodated in rectangular channel 67 is an actuator member 69 and a coiled compression spring 68 which contacts the rear wall of rectangular channel 67 and the rear end of actuator member 69. Actuator member 69 comprises a rectangular body portion 70, which is slidably mounted in rectangular recess 67,' and a forwardly projecting lug portion 71 having a downwardly depending heel portion 72 which slidably engages rectangular slot 39 in bolt body member 16, and an upwardly projecting toe portion 73.

Bolt 14 is held in recoil position against the bias of a driving spring (not shown) which urges bolt 14 forwardly when released by trigger means. As bolt head member 15 comes adjacent slot 27, in feedway 26, the upwardly extending rammer portion 52 projects therethrough to engage the base of cartridge 30 indexed in feeding mechanism 24. The engagement of rammer portion 52 with the base of cartridge 30 urges rammer-ejector 50 rearwardly against the bias of spring 68 and thus cushions the impact to provide a smoother initial movement of cartridge 30 down cartridge depressor 29'toward the chamber of barrel 21.

As cartridge 30 is moved forwardly and downwardly through slot 27, the base thereof moves out of contact with rammer portion 52 into engagement with the forward face of bolt head member 15 and ultimately into alignment with cylindrical recess 36 therein. Also during the forward travel of bolt 14, rammer-ejector 5G moves beyond the forward reach of actuator member 69 and out of resilient contact therewith.

As bolt 14 approaches the rear end of barrel-extension 20, the forward end of rammer portion 52 engages ramp portion 28 therein to cam rammer portion 52 downwardly against the spring bias of ejector portion 53 into slidable engagement with the top surface of channel 22, and bolt 14 continues forwardly to chamber cartridge 30. The forward thrust of bolt 14 against ehambered cartridge 30 results in the engagement of the base thereof with cylindrical recess 36 with the rim portion seated in the undercut periphery 0f cylindrical recess 36 and cartridge engaging head 34 of extractor 37 engaged in extractor groove 48. When cartridge 30 isengaged with cylindrical recess 36, the cartridge base contacts triangular lug 56 on the end of ejector portion 53 to hold rammer-ejector 50 rearwardly in head portion 15. In the rearwardmost position of ejector portion 53, relative to bolt head 15, triangular lug 56 thereon is engaged with triangular notch 44.

When bolt head member 15 reaches battery position, bolt body member 16 continues forwardly, thrusting ring pin 35 forwardly to fire cartridge 30. When cartridge 30 is fired, bolt 14 recoils and withdraws the fired cartridge case from the chamberV of barrel 21 by the engagement of the cartridge rim in the undercut of the periphery of cylindrical recess 36 and the engagement of cartridge engaging lug 34 of extractor 37 in extractor groove 48. The tired cartridge case is carried rearwardly by bolt 14 until heel portion 72 of actuator 69 re-engages rammer-ejector 50, with the upwardly projecting toe portion 73 assuring engagement, at which point the cartridge case is fully aligned with ejector port 32. Thus, actuator 69 urges rammer-ejector 50 forwardly in head member 15, with ejector portion 53 thrusting against the upper portion of the base of the cartridge case. Triangular lug 56 on ejector portion 53 assures contact thereof with the base of the cartridge The thrust ejector portion 53 unseats the rim of the cartridge case from the undercut periphery of cylindrical recess 36 and pivots the cartridge case around cartridge engaging lug 34 of extractor 37 to be expelled out of ejection port 32. Spring 68 is further compressed by actuator 69 as bolt 14 moves into full recoil position. It is obvious that the point at which the cartridge case is ejected during the recoil ilight of bolt 14 may be controlled by the length of spring 68 and actuator 69. Thus, as in the present embodiment Where it is desirable to eject the cartridge cases from the bottom rather than the side of the receiver to obtain a more compact firearm, the ejection port may be placedforward of the trigger mechanism intermediate the extremes of the bolt travel.

, There is seen by the foregoing description that there is here provided for automatic firearms a simple, rugged and compact means for feeding cartridges from a cartridge belt to the barrel chamber during counter-recoil of the bolt and for ejecting cartridges during the recoil.

I claim:

l. In an automatic firearm, a receiver having a feedway adapted to receive a linked belt of cartridges intermittently moved therethrough by feeding means rotatably mounted above the linked belt in said receiver, said feedway being provided with a longitudinally disposed opening in the center thereof, a bolt reciprocably mounted in said receiver for longitudinal movement between a battery and recoil position, said bolt having a longitudinally disposed slot in the upper part thereof arranged to slidably receive a rammer-ejector mechanism, said bolt being provided with a stop transversely disposed to said longitudinal slot for cooperation with a rectangular notch in said rammer-ejector mechanism thereby limiting the longitudinal movement of said rammer-ejector mechanism, a spring-biased actuator slidably mounted in the upper part of said receiver rearwardly of said mechanism arranged for biasing said mechanism forwardly during recoil, said mechanism having a rammer portion for urging a cartridge forwardly from the belt when said bolt is moving into a battery position, means for deliecting the cartridge downwardly through said opening into a chambered position, and an ejector portion of said mechanism for ejecting a spent cartridge case downwardly when said actuator biases said mechanism forwardly when said bolt is moving into the recoil position,

2. In an automatic firearm, a receiver having a feedway adapted to receive a linked belt of cartridges intermittently moved therethrough by feeding means rotatably mounted above the linked belt in said receiver, said feedway being provided with a longitudinally disposed opening in the center thereof, a bolt rcciprocably mounted in said receiver for longitudinal movement between a battery and recoil position, said bolt having a longitudinally disposed slot in the upper part thereof terminating in a T-slot rearwardly thereto, a springbiased rammer-ejector mechanism having protruding lugs on each sdethe'reof arranged for Vslidable''cooperation with said T-slot of said bolt, said bolt being provided with a stop transversely disposed to said T-slot for cooperation with a rectangular notch in said rammerejector mechanism thereby limiting the longitudinal movement of said rammer-ejector mechanism therein, said mechanism comprising an ejector portion arcuately shaped for resilient engagement with said slot in said bolt and having a rammer portion resiliently disposed above said ejector portion and protruding through said opening for urging a cartridge forwardly from the belt when said bolt is moving into a battery position, means for detiecting the cartridge downwardly through said opening into a chambered position, a barrel extension positioned in the forward part of said receiver and being provided with a forwardly and downwardly depending ramp in the rear end thereof whereby said rammer portion is deected downwardly against said ejector portion when the cartridge is chambered, and a spring-biased actuator slidably mounted in the upper part of said receiver rearwardly of said mechanism arranged for biasing said mechanism forwardly during recoil whereby said ejector portion ejects a spent cartridge case.

3. In a firearm having a bolt slidably mounted for reciprocal movement between a recoil and a counterrecoil position, and feed means for intermittently positioning a cartridge above the bolt and in parallel alignment with the longitudinal axis thereof, a unitary rammerejector member comprising a body portion having a diamond-shaped lug projecting transversely from either side thereof for slidable engagement in the top of the bolt, a rammer portion projecting forwardly and upwardly from said body portion beyond the face of the bolt, an

arched ejector portion projecting forwardly from said body portion beneath said rammer portion and terminating in a depending lug adapted to engage the base of a cartridge gripped in the front face of the bolt, and means in the bolt operative on said depending lug of said ejector portion for normally rocking said body portion rearwardly about said diamond-shaped lugs thereon to elevate the free end of said rammer portion for engaging the base of a cartridge during counterrecoil of the bolt.

4. In a firearm having a bolt slidably mounted for longitudinal reciprocal movement between a recoil and a counterrecoil position, a barrel having a firing chamber therein, a barrel extension projecting from the rear end of the barrel to form a recess for entry of the bolt at the conclusion of counterrecoil movement thereof, and feed means for intermittently positioning a cartridge above the bolt and in parallel alignment with the longitudinal axis thereof, the bolt having a substantially rectangular T-slot formed in the top thereof and extending forwardly from the rear end and having a `substantially rectangular groove extending forwardly from said T-slot and disposed in a higher elevational plane relative thereto, said rectangular groove terminating in a notch therein adjacent the face of the bolt, a unitary rammer-ejector member comprising a body portion having an underside surface sloping forwardly from the rear end thereof and an oppositely sloping surface extending forwardly from said rst surface to form a pivot point at the junction thereof, a diamond-shaped lug projecting from either side of said body portion for slidable engagement in said T-slot, said lugs being located with the converging surfaces on the underside thereof coinciding with said pivot point on the underside of said body portion, a rammer portion projecting forwardly from said body portion along said T-slot and upwardly out of said groove, an arched resilient ejector portion projecting forwardly from said body portion beneath said rammer portion and terminating in a depending lug engageable in said notch in the front end of said groove, said notch being in Va higher elevational plane than the normal position imparted to said depending lug as a result of the curvature of said ejector portion whereby said body portion is rocked about said pivot point thereof to position the free end of said rammer portion for engaging the base of the cartridge in the feed means during counterrecoil of the bolt, and cam means on the upper wall surface of the recess in the barrel extension operative on the free end of said rammer portion to rock said body portion of said rammer-ejector forwardly about said pivot point on the underside thereof and permit entry of said rammer portion into the barrel extension recess during the conclusion of counterrecoil of the bolt, said ejector portion being thereby resiliently biased to rock said body portion rearwardly upon disengagement between said rammer portion and the upper wall surface of the barrel extension recess to thereby return said rammer portion to a cartridge-engaging position.

5. In a firearm having a bolt slidably mounted for reciprocal movement between a recoil and a counterrecoil position, and feed means for intermittently positioning a cartridge above the bolt and in parallel alignment with the longitudinal axis thereof, a unitary rammerejector member comprising a body portion having a dit.- mond-shaped lug projecting transversely from either side thereof for slidable engagement in the top of the bolt, a rammer portion projecting forwardly and upwardly from said body portion beyond the face of the bolt, an arched ejector portion projecting forwardly from said body portion beneath said rammer portion and terminating in a depending lug adapted to project from the face of thc bolt and engage the base of a fired cartridge case being gripped thereby, means in the bolt operative on said depending lug for normally rocking said body portion rearwardly about said diamond-shaped lugs thereon to position the free end of said rammer portion for engaging the base of a cartridge in the feed means during counterrecoil movement of the bolt, an actuator slidably mounted in the path of movement of the rear end of said rammer-ejector member during recoil movement of thc bolt whereby said ejector portion is forced forwardly to protrude from the face of the bolt into contact with the base of an extracted cartridge case for effecting ejection thereof out of the firearm, and spring means biasing said actuator forwardly to cushion the impact thereof on the rear end of said rammer-ejector member and thereby impart a relatively smooth cartridge ejection movement thereto.

References Cited in the le of this patent UNITED STATES PATENTS 1,682,704 Loomis Aug. 28, 1928 2,113,202 Stange Apr. 5, 1938 FOREIGN PATENTS 681,676 Great Britain Oct. 29, 1952