US2394986A - Gas-operated self-loading firearm - Google Patents

Description

1946- H. L. CROCKETT GAS-OPERATED SELF-LOADING FIREARM F'il ed Feb. 1, 1945 2 Sheets-Sheet l Arromvcy;

Feb. 19, 1946. H. CROCKETT GAS-OPERATED SELF-LOADING FIREARM 2 Sheets-Sheet 2 Filed Feb. 1, 1945 Patented Feb. 19, 1946 GAS-OPERATED SELF-LGADING FIREARM Harry L. Crockett, New Haven, Conn, assignor to Olin Industries, Inc., New Haven, Conn, a corporation of Delaware Application February 1, 1945, Serial No. 575,602

9 Claims.

The present invention relates to improvements in self-doading firearms and relates more particularly to improvements in self-loading firearms of the type wherein gas-pressure from the bore of the barrel serves to actuate a piston which, in turn, actuates the breech-bolt and associated features of the firearm to eiiect the extraction and ejection of the just-fired cartridge, preparatory to the automatic reloading of the firearm with a fresh cartridge.

One of the objects of the present invention is to provide a superior firearm of the character referred to and in which the parts are constructed and arranged to minimize distortion of the bolt-operating slide under the stresses imposed thereon by the gas-operated piston.

Another object of the present invention is to provide a gas-operated self-loading firearm with a superior construction and arrangement of parts whereby the gas-operated piston applies its thrust upon a bolt-operating slide at a point laterally intermediate the guide-means for the said slide and the portion of the said slide which is operatively connected to the breech-bolt to operate the same, to thereby minimize flexing strains upon the said action-slide and to insure reliable operation of the firearm.

With the above and other objects in view, as will appear to those skilled in the art from the present disclosure, this invention includes all features in the said disclosure which are novel over the prior art.

In the accompanying drawings, in which certain modes of carrying out the present invention are shown for illustrative purposes:

Fig. 1 is a broken elevational View of the central portion of a gas-operated self-loading firearm embodying the present invention and looking toward the right side thereof;

Fig. 2 is a top or plan view of the showing of Fig. 1;

Fig. 3 is a View similar to Fig. 1 but looking toward the firearm-structure from the left side thereof;

Fig. 4 is a view of the showing of Fig. 3 mainly in underside and partly in horizontal section on the line 4-4 of Fig. 3;

Fig. 5 is a transverse sectional view taken on the line 5-5 of Fig. 3;

Fig. 6 is a similar view taken on the line 6-6 of Fig. 3; and

Fig. 7 is a broken perspective view of the forward-portion of the action-slide.

The particular gas-operated self-loading firearm herein chosen for purposes of illustrating one form of the present invention, includes a receiver I (ha barrel I I, a trigger-plate unit i2, an action-slide l3, and a breech-bolt [4.

The receiver l0 above referred to includes a top-wall l5 and integral side-walls l6 and [1. The forward-portions of the top-wall l5 and the side-wall H are cut away to provide an ejectionopening I8. The said ejection-opening is closed by the breech-bolt l4 when the latter is in its forward or breech-closing position, but the said ejection-opening is open when the said breechbolt is in its rearward position, in a manner common in the art.

The side-wall E6 of the receiver I0 is formed adjacent the forward end of the ejection-opening l8, with a forwardly-facing locking-abutment I9, while the opposite side-Wall I? is formed at a similar location with a forwardly-facing locking-abutment 2!). The locking-abutments l9 and 20 are adapted to be engaged by the respective rear-faces or edges of bolt-locking lugs 2| and 22. The said bolt-locking lugs 2i and 22 are formed integral with and respectively project in substantially-diametrically-opposite directions from the forward-portion of the breech-bolt l4.

Extending radially outwardly from the outerend of the bolt-locking lug 22 is an integral boltoperating lug 23 which projects into a cam-recess 24 formed in the inner-face of the enlarged rearportion 25 of the action-slide I3 before referred to.

The bolt-operating lug 23 of the breech-bolt l4 and the cam-recess 24 in the rear-portion 25 of the action-slide i tures embodied in the well-known Garand military rifie, and coact in such manner that when the action-slide i3 is moved rearwardly from the position in which it is shown in the drawings, the said cam-recess will coact with the boltoperating lug 23 to first turn the breech-bolt M in a clockwise direction (as viewed from the front) to disengage the bolt-locking lugs 2| and 22 respectively from the locking-abutments l9 and 20 of the receiver Hi. Following this unlocking movement of the breech-bolt, the coaction of the bolt-operating lug 23 and the surfaces of the cam-recess 2e will then efiect the direct rearward movement of the breech-bolt [4 until the latter reaches the limit of its rearward movement. Conversely, when the action-slide is moved forwardly, following the abovedescribed rearward movement thereof, the coaction of the bolt-operating lug 23 and the cam-recess 24 will first draw the said breech-bolt forwardly until such time as the respective rear-faces of its bolt-locking lugs 2i and 22 respectively register with the locking- 3, generally correspond to fea-- abutments l9 and 20 of the receiver l6, whereupon the breech-bolt M will be turned transversely in a counterclockwise direction to again lock the breech-bolt in its breech-closing position.

The enlarged rear-portion 25 of the actionslide 13 is integrally connected by means of a.

bar-portion 26 to a crosshead 21 forming the foremost part of the action-slide 13... The rearportion 215' and the-har-portion 2.5 of the action;- slide l3 are mounted for reciprocation adjacent the right'side of the barrel I l, and the crosshead 21 extends laterally from the forward-portion of" the said bar-portion 26 beneath the. saidbarrelto a point adjacent the left side of the latter- The upper-face of the crosshead '21: :is' for-med with a longitudinal upwardly-opening clearancegroove 28 which serves to accommodate the ad.- jacent portion of the barrel 151i andl-permit-lthe free reciprocating movement of the said cross:- he'ad with respect to the said barrel.

.Atia. point forwardly of. the. receiver Jill :and

also-forwardly of. the crosshead. of. the-actionslide l3, therbarnel H; :isiformed withandnteeral depending cylinder-lug .29 which .suficient breadth to extendnla-terall-y' beyond either side of the barrel l t-propenq'as isv especially-wellslrown in Fig. 6. Thesaidcylinder-l-ug, is formedqat. :a point directly beneath; the center line of the-bar:- rel ll; :a downwardly-opening; internaliythneadedi coupling; socket- 3.0; which is adapted to receive any, suitable coupling-screw (notshownr) which. may serve: to attach auitahlevstock Qalso not shown) to the barrel H.

In: its. lower right-hand portion, the cylinderl ug, 29 is formed, with a-piston-chamber which has: itsaxis extending in substantial parallelism with the longitudinal axis. of the barrel; 1 and which opens through the rear-iaceoi the cylinder-lug thesis: especially wellshownrin Fig; 4. Reciprocating in theipiston-chamber3i! :isra piston generally designated by the reference char- :aoter. 32 and including relatively-largee-diametenedahead; 33;:and an integral relatiyely sma'l-l- -diametered stem 34.. 'mieheadi 33'. constitutes the forward-portion. of the piston-1.32:, "while. the: stem 34 :pnoieotsrearwardly and hasits' rear -eendcnormaily' engaged; with the iorwardefane. of the crosshead 21. of" the. actionrslide. 13:.

The rear-portion of; the. pistonchamherfiil "in the cylinder-lug 2'19: is; enlarged and internally threaded :to. receive. ring-like externallythreaded stop-member L35. adapted. "to have: its

forward-face engaged by the reareface .of the head. of the piston 32' when the said piston. is

driven :rearvmardl-y, in a manner as. hereiniatter appean Eon-the pnrposez'ofoausing gas. .under pressure -toimpinge against theiorwardiendor the piston 32,. to thus drive "the said piston rearwardlmthe cylinder-lug: 2-93 .of. the banal. ill :is formedwith an: inclined gasepassage 35. which communicates at its: lower'end with the :fonvardxendwof the pistonchamber which communicates at its upend with the bore 37 of the barrel 41., as is indicatedin Figs. 1.14 and: 6.

In its lowerilefit-hand portion, theIfYllIIdGD-lllg 2d of the barrel id is formed with a socket '38 extending the said cylinder-lug from front wtoxrear insubstantial parallelismwith. the hone;- 35! of thexberrel ii. Supported'iin the; socket -38: in the oylinderelng: 'fi: :is. the forward end of a'gufdesrod. zed-which hasuits rear .end' threaded and entered. internally-threaded socket All formed in the. forward lower-portion of :the receiver .lal) adfiacentthe left side thereof, as is .head 21 of the action-slide I3, as is especially well shown in Figs. 4 and 5'.

In :itslowerright-hand portion, the crosshead 21 of the action-slide I3 is formed with a rearwardly-opening-socket 42 which is adapted to re-' ceivea stud lfi formed integral with and projecting' forwardly from the front end of a breechclosing plunger- 4A. At the base of the said stud 43 the breech-closing plunger 44 just referred to i's'formed with an integral collar '45 having its vterwancl-face engaged with. therear-iace of the crosshead 2?!- and havingits rear-face, ;in turn, engaged by theiorward. end of ahelical breechclosing spring d6. Thesaid breech-closingspring encircles themain-portion of the. said plunger 44 and extends at its rear into a forwardly-openin fipr-ins-wpocket 4 formed in the lower rig-hthand pcrtion oirthe right side-wall H ofthe receiver in, .as is especially well shown-in The rear end of the breech-closingyplunger M is also normally entered into; the forward-portion of. the spring-pocket fil -and is adapted to slide further rearwardly into. the sa-id- .spring pocket when-the action-slide l3-ispmoved rearwardly.

As. thus constructed and arrangedthe' :breechclosingspring 46, acting through the intermediary of: the breech-closingplunger 44 and the crosshead 2--'!-, acts to yieldingly hold the actionslide 113 in itsforward position and hence, also, to. yield-ingly hold the. breech-bolt M in its breech- .closing' position.

When the -;-firearm isdischarged in any suitable ..manne1:, gas" under. pressure will pass from, the

bore 31- of the barrel. H into the forward end of the. piston-chamber 3.1: in the. oylinder lug 2.9. The. saidgas will impinge against the forwardface of the head 33 of the piston .3i2 and drive the said piston. rearwardly a short distance, until: the

rear-wface-ofthe head 33iengages with theforwardface, .of .thelstop memhe.r 35. The .desori'bedrearward: movement of the piston s2: will cause. the

rear-face of the stem 34 to drive against-the ion ward'azfiace of the 'crosshead 2:1 at-a point. closely inl-i-ne. with the: breech-closing spring, 11.6 butat apoint laterally intermediate said spring and the guides-rod .39.

Thedcscribednrearwardmovement ofthepiston 332. will drive the action-slide rearward-1y and impart thereto a :nearwardmovement far in excess of: the relatively-short movement. of the piston 32 itself. As the action-slide moves rearwardly, the :crosshead. .21. will. slide on the "guide-rod 39 .and'will also: drive the zbreecheclosing plunger M rearwardly, to effect the compression of the breechaclosing. spring 4:6.

The rearward movement of the action-slide I 13 will unlock and retire the breech-bolt 14.. Up

onkthecompletionof itsrearw-ard movement, the action-slide [3 will be. reversed and moved 'forwardlyby'the action of the breech-closing spring 46, to thereby again restore the parts to the posiwhich they are shown in the drawings, preparatory toanother discharge" of the firearm. Bylocating'the: guid'e rod 39 piston 32 and breech-closing spring in the manner shown and'described, the said piston is caused to exert its relatively-violent rearward force in substantial alignment with both the breech-closing springs stand the bar-portion 26 of the actionslide, while the opposite side of the crosshead 21 is being steadied and guided by the guide-rod 35. In this manner, the distortion of the actionslide is so minimized as to enable the action-slide to function smoothly and without requiring that the said action-slide be excessively heavy in order to withstand excessive fiexural and cramping strains.

The invention may be carried out in other specific ways than those herein set forth without departing from the spirit and essential characteristics of the invention, and the present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

I claim:

1. A gas-operated self-loading firearm, including in combination: a receiver; a barrel projecting forwardly from the said receiver; a cylinderlug depending from the said barrel at a point forwardly of the said receiver and formed with a rearwardly-opening piston-chamber having its longitudinal axis extending in substantial parallelism with the longitudinal axis of the said barrel, the longitudinal axis of the said pistonchamber being located in a plane to one side of the vertical longitudinal plane extending through the longitudinal axis of the said barrel; a guiderod having its longitudinal axis extending in substantial parallelism with the longitudinal axis of the said barrel and located on the opposite side of the vertical longitudinal plane extending through the longitudinal axis of the said barrel, the said guide-rod having its forward-end engaged with the said cylinder-lug and having its rear-end engaged with the forward-portion of the said re ceiver; a breech-bolt movable longitudinally in the said receiver; an action-slide mounted for longitudinal reciprocation along one side of the said receiver and having a bearing-portion slidably engaging with the said guide-rod, the said action slide being operatively connected to the said breech-bolt for moving the same; a piston movable in the piston-chamber of the said cylinderlug and normally engaged with a forward-portion of the said action-slide to drive the latter rearwardly; and gas-conducting means extending between the bore of the said barrel and the forward-portion of the piston-chamber in the said barrel-lug.

2. A gas-operated self-loading firearm, including in combination: a receiver; a barrel projecting forwardly from the said receiver; a cylinder-lug depending from the said barrel at a point forwardly of the said receiver and formed with a rearwardly-opening piston-chamber having its longitudinal axis extending in substantial parallelism with the longitudinal axis of the said barrel, the longitudinal axis of the said pistonchamber being located in a plane to one side of the vertical longitudinal plane extending through the longitudinal axis of the said barrel; a guiderod haw'ng its longitudinal axis extending in substantial. parallelism with the longitudinal axis of the said barrel and located on the opposite side of the vertical longitudinal plane extending through the longitudinal axis of the said barrel, the said guide-rod having its forward-end engaged with the said cylinder-lug and having its rear-end engaged with the forward-portion of the said receiver; a breech-bolt movable longitudinally in the said receiver; an action-slide mounted for longitudinal reciprocation along the side of the firearm-structure on which the said piston-chamber is located, the said action-slide being operatively connected at its rear with the said breechbolt and having adjacent its forward-end a bearing-portion slidably engaging with the said guiderod; a piston movable in the piston-chamber of the said cylinder-lug and normally engaged with a forward-portion of the said action-slide to drive the latter rearwardly; and gas-conducting means extending between the bore of the said barrel and the forward-portion of the piston-chamber in the said barrel-lug.

3. A gas-operated self-loading firearm, including in combination: a receiver; a barrel projecting forwardly from the said receiver; a cylinderlug depending from the said barrel at a point forwardly of the said receiver and formed with a rearwardly-opening piston-chamber having its longitudinal axis extending in substantial parallelism with the longitudinal axis of the said barrel, the longitudinal axis of the said pistonchamber being located in a plane to one side of the vertical longitudinal plane extending through the longitudinal axis of the said barrel; a guiderod having its longitudinal axis extending in substantial parallelism with the longitudinal axis of the said barrel and located on the opposite side of the vertical longitudinal plane extending through the longitudinal axis of the said barrel, the said guide-rod having its forward-end engaged with the said cylinder-lug and having its rear-end engaged with the forward-portion oi the said receiver; a breech-bolt movable longitudinally in the said receiver; an action-slide mounted for longitudinal reciprocation along One side of the said receiver and having a head-portion adjacent its forward-end which head-portion is provided with a bearing-portion slidably engaging with the said guide-rod, the said action-slide being operatively connected adjacent its rearend to the said breech-bolt for moving the same; a piston movable in the piston-chamber of the said cylinder-lug and normally engaged with the head-portion of the said action-slide to drive the action-slide rearwardly; and gas-conducting means extending between the bore of the said barrel and the forward-portion of the piston chamber in the said barrel-lug,

4. A gas-operated self-loading firearm, including in combination: a receiver; a barrel projecting forwardly from the said receiver; a cylinder-lug depending from the said barrel at a point forwardly of the said receiver and formed with a rearwardly-opening piston-chamber having its longitudinal axis extending in substantial parallelism with the longitudinal axis of the said barrel, the longitudinal axis of the said pistonchamber being located in a plane to one side of the vertical longitudinal plane extending through the longitudinal axis of the said barrel; a guiderod having its longitudinal axis extending in sub stantial parallelism with the longitudinal axis of thesaid barrel and located on the opposite side of the vertical longitudinal plane extending through the longitudinal axis of the said barrel, the said guide-rod having its forward-end engaged with the said cylinder-lug and having its rear-end engaged with the forward-portion of the said receiver; a. breech-bolt movable longioneness side of thefirearm-structure on which thezsaid piston-chamberis located: and having aheadportion adjacent; its fnrwardeend which. head;- porin'on extends transversely beneath the barrel into bearing engagement with the said guide-rod, said action-slide being operatively connected adjacent its rear-end to. the said; breech-boltfor moving th same; a pistonqmovable in the/pistonchamher or the saidT-cylinder-lug and normally engaged with the head-portion of the said-actionslide to drive: the; action-slide rear-wardly; and gas conducting means extending between. the of the said barrel and the; forward-portion of the. pistonech-amber in the said barrel-lug.

5. A gas-operated self-loadingfirearm-,pinGludincomhinationz; a receiver; a barrelprojecting forwardly from thesaid receiver; a cylinderlug depending from the said barrel at a. point forwardly of the said receiver; and formed with a rearward-wh tening, piston echamber having its longitudinal, axisex-tending in substantial parallelism with the longitudinal axis of the said barrel, the longitudinal axis of the. said pistonchamber being located in apl'aneto one side or the vertical longitudinal plane extending through the longitudinal axis of the said barrel; a guiderod having its longitudinal, axisextendingin substantial parallelism with the, longitudinal axis of the said barrel and located on the, opposite side of the vertical longitudinal plane, extending through the longitudinal axis of the said barrel, the said guide-rod having its forward-end envgaged with the said cyl-in-derelug. and. having its rear-end engaged with the forward-portion of the said receiver; abreech-bolt movable longitudinally in the said receiver; an action-slide mounted for longitudinal reciprocation along one side of' the said receiver and having a bearingportion slidably engaging with the said guiderod, the said action-slide being operatively connected to the said breech-bolt for moving the same; a helical breech-closing spring. thrusting forwardly upon the said action-slide and extend ing in substantial parallelism with the saidguiderod but located on the opposite side of the firearm-structure therefrom; a piston movable in the piston-chamber of the said cylinder lug vand normally engaged with-a forward-portion of the said action-slide to drive. the latter rearwardly; and gas-conductingimeans extending between the bore of the said barrel and the forward-portion of the piston-chamber-in the said barrel-lug.

'6. Al gas-operated self-loading firearm, including in combination: a'receiver; a barrel projecting forwardly from the said receiver; a cylinder-lug depending from the said barrel at a point forwardly of the said receiver and formed with a rearwardly-opening piston-chamber having its longitudinal axis extending in substantial parallelism with the longitudinal axis of' the said barrel, the longitudinal axis of the said piston-chamber being located in a plane to one 'sideof the vertical longitudinal plane extending through the longitudinal axis of the said barrel; a guide-rod havingits longitudinal axis extending in substantial parallelismwiththe longitudinal axis of the said barrel and located on the opposite side of the vertical longitudinal plane extending through the longitudinal" axis of the said barrel, the said guide-rod having its forward-end engaged with the cylinder-lug andhaving its rear-end engaged the forward-portion of the said receiveni a breecmbolt; movable longitudinally in the; said receiver; an. action-slidemounted for longitudinal, reciprocation along the side of the firearmestructure on which-the said piston-chain.- ber is located, the; saidaetion-slide; being operatively-connected attits'. rear with the said breech- .bolt and having adjacent its forward-end a bearing-portion slidably' engaging with the said guide,- rod; a. helical breech-closing spring, thrusting forwardly upon; thevsaid action-slide and extending 'in substantial parallelism with the said guiderod but located on the opposite side of theme? arm-structure. therefrom; a piston movable in the'piston-chamber of the-said cylinder-lug; and normally engaged: with a: forward-portioniof the said. action-slide to drive the latter rearwardly;

and gas-conducting means. extending between the bore: of thesaid barrel and thevforward-pertion of the. piston-chamber in the: said barrel- 7. A gas-operatedself-loading firearm; include ing in combination; a receiver; a barrel projecting- Iorwardly from the, said receiver; a cylinderlug depending fromthe said barrel at a point forwardly of the-said receiver and formed with a rearwardly-openi-ng piston-chamber having its longitudinal axis extending: in substantial, parallelism with the longitudinal axi of the-said bar-- rel, thelongitudinal axis of the said piston-chain her being located in a, plane to one side of the vertical longitudinal plane extending through-the longitudinal axis of the said barrel; a guide-rod havingitslongitudinal axis extending in substantial parallelism with the longitudinal axis of the said barrel and located on the opposite side of the, vertical longitudinal. plane extending through the longitudinal axis of the said. barrel, the, said 7 guide-rod havingi'ts forward-end engaged with the said cylinder-lug and having its rear-endangaged with the forward-portion of. the said receiver; a, breech-bolt movable longitudinally in the said receiver;v an action-slide mounted for longitudinal reciprocation along one side. of the said receiver and having .a head-pontionadjacent .its forward-end which'head-port'ion is provided witha bearing-portion slidably engaging with the said guide-rod, the said .actionrslide being operatively connected adj acentits rear-end to the said. breech-bolt for moving the same; a helical breechrclos'ing, spring thrusting. forwardlyupon the head-portion oi thev said action-slide andextending, in substantial parallelism with. the-- said guiderrod but located on. the opposite sidesof the firearm-structure therefrom; a, piston movable in the piston-chamber of the said cylinder-lug and normally engaged with the head-portion of the said action-slide to drive the, action-slide. rearwardly; and gas-conducting meanslextend'ing be. tween the bore of the said barrel. and the forward-portion of the piston-chamber in the said barrel-lug.v

'8. A gas-operated self-loading firearm, includ- 1 ing in combination; receiver; a barrel projecting forwardly from the said receiver; a. cylinderlug depending from the said-barrel. at a point forwardly of the said receiver and formed with a rearwardht-opening piston-chamber having. its longitudinal axis extendingin substantial. parallelism with the longitudinal axis. of. the said barreLtheJongitudinaI axis. of the said piston-chamber being located in a plane to one side-of the 7 vertical longitudinal plane extending throughthe longitudinal axisof the sa'idbarrel; aguide-rod having-its longitudinal axis extending in substantialparallelism with the longitudinal axis of the said barrel and located on the opposite side of the vertical longitudinal plane extending through the longitudinal axis of the said barrel, the said guide-rod having its forward-end engaged with the said cylinder-lug and having its rear-end engaged with the forward-portion of the said receiver; a breech-bolt movable longitudinally in the said receiver; an action-slide mounted for longitudinal reciprocation along the side of the firearm-structure on which the said piston-chamber is located and having a head-portion adjacent its forward-end which head-portion extends transversely beneath the barrel into bearing engagement with the said guide-rod, the said action-slide being operatively connected adjacent its rear-end to the said breech-bolt for moving the same; a helical breech-closing spring thrusting forwardly upon the head-portion of the said action-slide and extending in substantial parallelism with the said guide-rod but located on the opposite side of the firearm-structure therefrom; a piston movable in the piston-chamber of the said cylinder-lug and normally engaged with the head-portion of the said action-slide to drive the action-slide rearwardly; and gas-conducting means extending between the bore of the said barrel and the forward-portion of the pistonehamber in the said barrel-lug.

9. A gas-operated self-loading firearm, including in combination: a receiver; a barrel projecting forwardly from the said receiver; a cylinder lug depending from the said barrel at a point forwardly of the said receiver and formed with a rearwardly-opening piston-chamber and with a rod-receiving passage, both the said pistonchamber and the rod-receiving passage extending in substantial parallelism with the longitudinal axis of the said barrel and respectively located on opposite sides of the vertical longitudinal plane extending through the longitudinal axis of the said barrel; a guide-rod having its longitudinal axis extending in substantial parallelism with the longitudinal axis of the said barrel and having its rear-end threadedly engaged with the forward-portion of the said receiver'and having its forward-end located in the rod-receiving passage of the said cylinder-lug; an action-slide mounted for longitudinal reciprocation along one side of the said receiver and having a head-portion adjacent its forward-end which head-portion is provided with a. bearing-portion slidably engaging with the said guide-rod, the said action-slide being operatively connected adjacent its rear-end to the said breech-bolt for moving the same; a piston movable in the piston-chamber of the said cylinder-lug and normally engaged with the headportion of the said action-slide to drive the action-slide rearwardly; and gas-conducting means extending between the bore of the said barrel and the forward-portion of the piston-chamber in the said barrel-lug.

' HARRY L. CROCmTT.

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