US2494220A - Ejector pin and breechblock assembly for firearms - Google Patents

Description

Jan. 10, 1950 D. M. WILLIAMS EJECTOR PIN AND BREECHBLOCK ASSEMBLY FOR FIREARMS Filed Oct. 4, 1947 Patented jan. 10, 195i) arse s EJECTOR PIN AND BREECHBLOCK ASSEMBLY FOR FIREARMS Application October 4, 1947, Serial No. 777,944

4 Claims.

The present invention relates in general to firearms and more especially to the ejector-andbreechblock assembly of an automatic self-loading firearm of the type disclosed in my oo-pending application Serial No. 733,617 filed March 0, 1947.

An object of the invention is to provide an ejectorandbreechblock assembly of superior construction.

A further object of the invention is to provide superior means for mounting and retaining an ejector-pin in a breechblock so that the ejectorpin may be assembled in and disassembled from the breechblock with dispatch and without the necessity of removing fastening-means or other elements of the breechblock.

A still further object of the invention is to provide superior construction embodying a minimum number of elements for mounting and retaining an ejector-pin in a breechblock and wherein the elements are durable, economical to manufacture and reliable in operation.

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, and which are not claimed in any separate application.

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

Fig. 1 is a broken side elevation partly in section of an automatic self-loading firearm embodying the improved ejector-and-breechblock assembly of this invention;

Fig. 2 is an enlarged fragmentary sectional elevation in a longitudinal vertical plane of the firearm of Fig. 1 showing the breechblock in breechclosing position and the ejector-pin supported therein in its normally retracted position;

Fig. 3 is a top plan view of the breechblock showing the ejector-pin mounted in one side thereof;

Fig. 4 is a front view of the breechblock showing the aperture in the front face thereof through which the ejector-pin is adapted to prothe latter is described as used in conjunction with an automatic self-loading firearm of the typed disclosed in the aforementioned application, but it is to be understood that the improved ejectorpin-and-breechblock assembly of this invention is applicable to other types of firearms.

In brief, the firearm includes a receiver H], a trigger-plate I I removably mounted on the underside of said receiver adjacent the rear end thereof, a barrel indicated by the reference character l2 secured at its rear end by a threaded connection or the like in the front wall of the receiver, a tubular magazine indicated by the reference character I3 secured at its rear end in the front wallof the receiver and at its forward end to the barrel and a buttstock indicated generally at Id secured to the rear wall I5 of the receiver.

The receiver l0 has a top wall l6 and side walls I! and I8 depending therefrom to form a substantialy-inverted-U-shaped chamber for accommodating the breechblock and the fire-control mechanism. The latter is mounted in the triggerplate l and embodies a pivoted hammer l9 and a trigger indicated generally at 20 for locking and releasing the hammer. Since the fire-control mechanism is not essential to a full disclosure of the invention, further details of this mechanism are omitted.

The breechblock or action of the firearm is indicated generally at 2 I, as shown particularly well in Figs. 3, 4, 5 and 6, and is adapted to be supported in the receiver for both longitudinal and pivotal movement therein. The longitudinal and pivotal movements of the breechblock are controlled in part by means of an operating-link 22, the forward end of which is pivotally connected to the breechblock by a transverse pivot-pin 23. The rear end of the operating-link 22 is pivotally connected to the forward end of an inertia-bar 24 which is supported for longitudinal sliding movement in a sleeve 25 secured to the rear wall l5 of the receiver, the sleeve extending rearwardly through a longitudinal aperture of the buttstock M. An action-spring 26 is supported in an axially-aligned aperture of the buttstock rearwardly of the inertia-bar 24 and is adapted to abut the rear end of the latter to resist rearward displacement thereof and to return the latter, including the operating-link 22 and breechblock 2 l, to their respective forward positions in the receiver following the discharge of the firearm.

As pointed out in the application referred to above, the breechblock 2| is adapted to be locked in breech-closing position by engagement of the rear end of itslocking-lug 21 with the forwardlyfacing shoulder 28 of a longitudinal aperture 29 formed in the top wall of a chamber-extension 33. The latter constitutes one element of a chamberunit which is supported for limited longitudinal spring-loaded firing-pin 3| and the extractor 32,-

the breechblock is characterized by superior construction for assembling and disassembling its ejector-pin. The latter is indicated generally at 33 and, in brief, is adapted to be mounted in the breech-bolt for longitudinal sliding movement therein, as hereinafter described, the rear end of the ejector-pin being resiliently held normally rearwardly of the rear end of the breech-bolt, as shown clearly in Figs. 2 and 3, so as to strike against the rear wall l5 of the receiver when the breech-bolt arrives at the end of its rearward excursion to thrust the forward end of the ejector-pin forwardly beyond the front face of the breech-bolt and hence forcibly eject a fired cartridge out of the ejection-port in the side 11 of the receiver.

More particularly, the ejector-pin 33 is a substantially' straight length of steel or other suitable material which is yieldable or flexible in a direction transverse to its longitudinal axis and comprises a cylindrical stem-portion 34 and an integral shank-portion 35, the latter being substantially one-third the length of the pin and formed at the rear end thereof, which is the end that is adapted to strike against the rear wall l5 of the receiver. I I

The shank 35 is provided with a longitudinal substantiallytriangular-shaped clearance-cut 36, the apex of which is at the forward upper outside corner of the shank and extends rearwardly and inwardly intersecting both the top and outside wall of the shank so as to conform the latter to the profile of the breechblock and, hence, provide clearance between the shank-portion of the ejector-pin and the top wall of the chamber-extension;

The shank-portion of the ejector-pin is Sllb stantially square in cross section at its Junction with the rear end of the stem 34, the width and height of this portion of the shank being substantially one-half again as gi'eat a the diameter of the stem. As indicated especially well in Fig. 3, the shank is offset laterally outwardly with respect to the stem, whereby the inside walls 31 and 38 of the shank and stem respectively are in alignment, the forward-and-outWardly-projeet ing end of the shank being joined to the rear end of the stem by an upper filleted shoulder 39. A major portion of the underside of the shank is provided with a longitudinal relief-recess which forms a depending transverse rearwardly-facing shoulder 40 adjacent the forward end of the shank and a stepped substantially flat support ing -surfa'ce 4| on the underside thereof which intersects the rear end of the shank, the depth of the relief recess being such that the height of the stepped-portion 42 "of the shank is substan tially one half of the height of the forward shouldered portion thereof and substantially equal to the height of the guide-recess for the stepped-portion 42 of the shank as described Below.

l-leretofore, it has been the practice to provide a longitudinal aperture extending throughout substantially the entire length of the breechblock for slidably supporting an ejector-pin. The method and means for forming this relativelylong aperture has been tedious, time-consuming and expensive, and it is an important contribution of the present invention to provide improved construction which insures superior means for supporting and retaining the ejector-pin in the breechblock.

To these ends, the breechblock is provided with a vertical relief-recess 43 which intersects the top and left-hand side thereof, the clearancerecess 43 being substantially-L-shaped in cross section, as indicated clearly in Fig. 5, and formed intermediate the front and rear ends 44 and 45 respectively of the breechblock so as to provide a breechblock head-portion 48 and a breechblock heel portion 41, the former haVing a substantially-vertical rearwardly-facing wall 48 corresponding to the forward wall of the recess 43 and the latter having a substantially-vertical forwardly-fac'ing wall 49 corresponding to the rear wall of the recess 43. In the present embodiment,- the length of the relief-recess 43 is slightly more than one-half the length of the ejector-pin, but it will be understood that these proportions may vary.

Formed in the head-portion 4B of the breechblock is a longitudinal guide-aperture 50, the opposite ends of which intersect the front end or face 44 of the breechblock and the rearwardlyfacing wall 38 of its head-portion 46, the longi tudinal aperture 58 lying substantially in the horizontal plane of the firing-pin which, in the present embodiment, slopes upwardly and rear wardly from its point of intersection with the front face of the breechblock. Moreover, the longitudinal guide aperture 50' slopes outwardly and rearwardly at a slight angle to the longitudinal axis of the breechblock, as indicated clearly in Fig. 3, the diameter of the aperture being only slightly greater than the diameter of the stem 34 of the ejector-pin, whereby the latter is adapted to make a smooth sliding fit therein.

The heel-portion 4! of the breechblock is provided with a guide-recess 5i which, in the present embodiment, is substantially-U-shaped in cross section with its open side intersecting the left= hand side of the breechblock and its front and rear ends intersecting the forwardly-facing wall as of the recess 43 and the rear end 45 of the breechblock respectively. The longitudinal axis of the guide-recess 5| is in axial alignment with the longitudinal guide-aperture 50, while the width and height of the guide-recess 5i are only slightly greater than the corresponding dimensions of the stepped-portion 42 of the ejectorpi'n shank 35, whereby the stepped-portion 42 is adapted to make a close sliding fit in the guide recess 5|. In this connection, it will be noted on reference to Fig. 5 that the bottom of the re= cess is wider than its top, the width of the latter being reduced by slabbing off the front face of the heel-portion of the breechblock above the upper edge of the recess 5| so as to facilitate removing the shank-portion of the ejector pin therefrom, as hereinafter described Referring particularly to Fig. 6., it will be seen that the bot-'- tom 52 of the L-shapd relief-recess 43 of the breechblock is below the bottom wall of the guiderecess 5!, as a consequence of which the forward end of the latter forms a substantiany-square shoulder 53 with the rear wall 49 of the reliefrecess 43.

The ejector pin is adapted to be mounted in the breechblock by inserting the forward end of portion 34 of the ejector-pin within the relief--' recess 43 of the breechblock and is engaged at its forward end against the rearwardly-facing wall 48 of the breechblock and at its rear end against the upper fllleted shoulder 39 of the ejector-pin, the compression force of the spring acting rearwardly thereon to resiliently hold its depending-shoulder 40 in engagement with the shoulder 53 at the rear end of the relief-recess 43. This position of the ej ector-pin in the breechblock is its normal position in which, as ShOWIl'ib in Figs. 2 and 3, the forward end of the pin is substantially flush with or slightly to the rear of the front face 44 of the breech-block, the rear end of the shank-portion of the pin projecting rearwardly beyond the rear end of the breechblock. Hence, when the breechblock approaches the end of its rearward excursion in the receiver, the rear end of the ejector-pin will strike the rear wall [5 of the receiver thereby driving the ejector-pin forwardly so as to compress its spring 54 and thrust the forward end of the pin beyond the front face of the breechblock so as to positively kick an extracted shell out of the ejection opening in the side of the receiver.

Since the shoulder 40 of the ejector-pin engages normally against the shoulder 53 of the recess 43,

the pin is positively held from moving rearwardly out of the guideways 56 and 5| of the breechblock. Moreover, since the forward end of the ejector- As soon as the breechblock starts forwardly in the receiver,

pin is engaged in the guide-aperture 50 of the head-portion 46 throughout substantially the entire length thereof, it is impossible for the stepped shank-portion 42 of the pinto be inadvertently deflected outwardly from the guiderecess 5! so as to disengage the coacting shoulders and of the pin and relief-recess 43 respectively and hence release the pin.

However, since the ejector-pin is formed of a relatively-still" but flexible material, the pin may be disassembled from the guideways 50 and 5| of the breech block b gripping the rearwardlyprojecting shank-portion of the pin and positively flexing the latter outwardly laterally sufficiently to free it of the top edge of the guide-recess 5| and then flexing the pin upwardly by the slabbedofi front face of the breechblock-heel to raise the depending shoulder 48 of the pin up out of engagement with the shoulder 53 of the'relief-recess 43. The pin may then be withdrawn rearwardly out of the guide-aperture 50 of the breechblock-12:

head. To assemble the ejector-pin and breechblock, the coil-spring 54 is first mounted on the stem-portion 34 of the ejector-pin, whereupon the forward end of the latter is inserted into the rear end of the guide-aperture 50. "The pin is the relief-recess 43, whereupon the ejector-pin is-released, the force of the flexed pin swinging the stepped shank-portion 42 thereof back into the guide-recess 5L By supporting the ejector-pin at its opposite ends in widely-spaced guideways of the breechblock, the necessity for drilling an aperture through the entire length of the breech-bolt is obviated, thereby effecting important savings in the length of time and number of tools heretofore required for forming the ejector-pinguideaperture. Moreover, by providing an open-sided 'recess and coacting shoulders on the ejector-pin and breechblock, the pin is securely held in its normal operative position in the bolt without requiring the use of pins or other auxiliary fastening-means and yet the ejector-pin may be readily disassembled from or assembled in the breechblock with facility and dispatch.

Although an ejector-pin having a substantiallyrectangular shank-portion is wholly satisfactory from a standpoint of reliability and efliciency of operation, it is also within the purview of the invention to form the ejector-pin with an enlarged cylindrical shank-portion adapted to snap into a longitudinal recess of substantially-semicylindrical cross section in the heel-portion of the breechblock, the upper and lower shoulders of the eJector-pin comprising a substantially-dish shaped flange formed integrally on the ejectorpin at the junction of its stem-portion and cylindrical shank-portion.

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. An ejector-and-breechblock assembly for firearms, including in combination: a breechblock having a substantially-vertical relief-recess intersecting the top and one side thereof, said relief-recess being formed intermediate the front and rear ends of said breechblock so as to provide a breechblock head-portion and a breechblock heel-portion, the said headand heel-portions of said breechblock having longitudinal axiallyaligned guideways therethrough; a flexible ejector-pin constructed and arranged to be mounted at its opposite ends in the respective guideways of the headand heel-portions of said breechblock; and means to slidably retain said flexible ejector-pin therein comprising a shoulder on said ejector-pin arranged to engage the front wall of said breechblock heel-portion when said pin is in its normal unflexed position in said guideways and to disengage the said front wall when said pin is flexed outwardly and upwardly, thereby to permit said pinto be removed rearwardly out of said guideways, resilient means mounted in the reliefrecess of said breechblock and arranged normally to resiliently hold the shoulder of said pin against the said front wall of said breechblock-heel, and a shank-portion at the rear end of said ejector-pin arranged normally to seat in the guideway of said breechblock-heel and to be withdrawn from the said guideway by flexing said pin outwardly and upwardly.

2. An ejector and-breechblock assembly for firearms, including in combination: a breechblock having a substantially-vertical relief-recess iintersecting .the :top I', and 70116- side itheieof, said :relief recess beingzformed intermediate-atheitfront randrrear ends of said-breechblock:soeastto provide a breechblock head-portionaand a1breeohabiockrheel-portion, sai'dbreechblockheade-portion I having a guideaperture.:extending longitudinally qtherethrough; a: guiderecess-linathe heel-portion .of said breechblock extending dongitudina-lly ltherethrough and 'inlaxial :alignment with i-the vlongitudinal axis of :said guide-aperture, said guide-recess cross section and intersectingthe said one-,sideof :sa-id ibreechblock; -.a flexible ejector-yin con- :structed and arranged to beymounted-vati-itstop- .posite ends respectively :in said gu-ideeaperture "and said guideerecess for-longitudinal movement therein; and means toslidably.retainsaidlejector- .pin .in' the respective guide-aperture -,-and=.;guiderecess of said breechblock.oomprisingza trans- .verse 'shoulderon said .ejectore-pin arranged to engage-the front wall'ofsaid-:breechblock heelj portion when said pin is in.its 'normallunfiexe'd position in said guide-aperture z-and said;gguide :recess-and to disengage-the said front-wall when said pin isflexed .outwardly and upwardlyethereby .topermitsaid pin to be'moved; rearwardlyoutof esaid guide-aperture and-said guide=recess,.resili- .-.ent meansmounted inthe relief-.recesse'ofssaid breechblockand arranged normally to'resiliently .hold theshoulder of'saidpin'against thesaidfront ,wall of said breechblock-hee1,;and a shank-portion at the rear end of said-pin,.saidz shankeportion-being substantially rectangular 1113,91055586 :.tion and arranged to fit slidablydn. theKU shaped guide-recess of -said breeehblock; heel-portion :to hold said ejector-pin from vrotatingtherein, said lshank-portion being arranged to;.be withdrawn laterallyf-rom the said guide-recess. in said breech- -.block-.heel. by flexing said pin outwardly,..there.by to permit flexing of said .pin upwardlyanddisassembly thereof .irom said. breechblock.

3. An ejector-and-breechblock assembly ;for firearms, including. in combination zlalbreechblock having a substantially-vertical relief-necessititersecting the top and. one sidathereoLsaid reliefrecess being formedintermediate-=the .froritand ,..rear ends .of said breechblock.soasito providez-a breechblock head-portion anda breechblo'ck heel- ,portion, said breechblock head-l-portionhavingpa guide-aperture extending longitudinally .,therethrough; a guide-recess in the;heel-:.portion...of said breechblock extending I longitudinally therethrough andin axial alignment withlthe'llongi- 'tudinal axis of said guide-aperture,..said guiderecess being substantially-U -shaped lin crosslsectionandintersecting .the said .one. 'side of..said breechblock; a .fiexible ejector-pin lhavin .an upper shoulder, said ejector-min ,beingimounte'd at its opposite ends respeCtivlyIinsaid guideaperture and said guideerecess.for;longitudinal .movementtherein; and means to .slidablyretain said ejector-pin in therespectiveggiiideeaperture .andguide-recess ofv saidflbreehblock compr ising a depending shoulder on said ejectorepin arranged toengage the front wallof .said'breehblo'cklhel portion when .said .pin. is inj its. normal ...unfiexe"d position in said guide-apertureandSaidguiderecess and to disengageithe-saidjrontwallwhen 1 said pin is flexed outwardly and upwardlyithereby .to permit said pin to.be.. moved rearwardlyoht of said guide-aperture-and said guiderrecess, .a,.co'ilspring mounted on said ejector-pininthewreliefrecess: of. said breechblock, one .end of said coil- ..spring being :engaged against the said upper .10 being substantially-Ueshaped in :shouldenofesaidgpini and the opposite-lend oflsaid lspringabeingengaged. against the. rearvwalllof said r:breeehbloek-theadatosexertnormally a rearwardly- :directed thrust .against '-.said upper shoulder to :resilientlysholdthe :depending. transverse shoulder againsti the front-wall of said .breechbloekeheel, :and a shank-portion :at :the rear end of .said lejector pin, said ;shank+portion .being substantt-ially rectangular in .cross section and. arranged ltoisfit sl-idablyr-in the EU eshapedzguidedecess. .of :gsaidbreechblock heel=portion to hold-said-eiectorpin :from rotating .therein, said wshank portion rbe-ing-arranged tobe withdrawn laterally from the said guide-recess in said breechblock-heel.byflexing said; pin outwardly thereby. to. permit flexing -.of said pinupwardly and disassemblythereof'from ssaid :breechblock. v

A. An :ejeetor-and-breechblock assembly .Tfor ..fi11earms,--.includin g in ,combination: .a .breechblock having: asubstantially-vertical relief -recess intersecting the top and one side .thereof,. said zrel'iefereoesszbeing formed intermediate the-front and rear ends ofsaidbreechblock soas to,.provide a :breechblock .headmortion. and .a breechblocli heel? portion, saidlbreechblock. head portionlhav- .ing -.a guide-aperture extending longitudinally 'therethrough; aguide-recess. .in ,the heelportion of said breechblock extending longitudinally .therethroughand inaxial alignment with ,the (longitudinal axis .of said .gui'deeaperture, .s'aid ;guiderecess Ebeing substantia1ly U.,shaped ain crosssection andintersectinglthe said one side, of .said. breechblock; a flexible. ej ector pin. having an upper sh0ulder,.saidiejectorepinflbeing mounted .at its opposite ends respectively insaidguide- .aperture and said guide-recess for longitudinal movement-therein; andmeans to slidably retain said ejector-pin in the respective guide=aperture .andguide-recess of said breechblock comprising :aJdepending transverse. shoulder on said. ejectorpinarranged Lto .engage ,the front wall of said .breechblock.heeleportion when said pinis'in its normal .un'flexed position in said guide-aperture .and said guideerecess an'dto disengagethe said ifrontwall when saidpin is'flexed outwardly and .upwardly thereby, to permit saidpin" to be moved rearwardly out of said guide-apertureandsaiid guide-recess, a coil-spring .mounted on said ejector pin in the relief-recessof said breechblock, one end'o'f'said coil-spring being engaged against the said upper-'shoulderof-said pin and the opposite end of said-spring being engaged'against the rear wall of said breechblock head "to exert ;normally a =rearwardly directed thrust :against said upper shoulder to resiliently hold the depending transverse"shoulder -against the front wall. of said breechblock heel, -a shank-portion at the rear end of saidejector-pin, said shank-portion being substantially rectangular in cross section and arranged to fit'slidably in theiU -shape'cl guide- "recess of said *breechblo'ck heehportion to their! said ejector-pin from rotating itherein, rsaid "shank-portion being i arranged .to be' withdrawn laterally ifrom the said guideerecess in said lfifi breechblo'ck-heel iby :flexing said pin outwardly "thereby :to' permit iflexing of ,said pin upwardly sand."disassembly thereof from :said breechblock, "and :a clearance-lcut ion the .outer face of the shank-portion 'ofatheg said ejectorepinto conform mesaid:shank-portion to-the profile of the corre :sponding: side. of saidbreechblock.

iDAVIllM. -.WILLIAMS.

No references cited.

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