US2290778A

US2290778A - Bolt-action firearm

Info

Publication number: US2290778A
Application number: US295188A
Authority: US
Inventors: Carl G Swebilius
Original assignee: Western Cartridge Co
Current assignee: Western Cartridge Co
Priority date: 1939-09-16
Filing date: 1939-09-16
Publication date: 1942-07-21
Anticipated expiration: 1959-07-21

Description

C. G. SWEBILIUS BOLT-ACTION FIREARM Filed Sept. 16, 1939 Vjx 2l, 1942.

3 Sheets-Sheet 1 Ew mm 1 22 N: Y E f/N/// @n w N O w S j IIL 5..... son Ei?? l.. N v om Q @hm E@ @mm Patented July 2l, 1942 2.390.773 Bour-ACTION maEAaM Carl G. Swebiiius, Hamden, Conn., assiznor to Western Cartridge Company, New Haven, Conn., a corporation of Delaware Application September 16, 1939, Serial No. 295,188

2 Claims. (Cl. 42-17) 'Ihis invention relates to improvements in boltaction firearms and relates more particularly to a construction and arrangement of parts whereby a breech-bolt and its associated parts are retained in place in the structure.

One of the objects of the present invention is to provide a superior bolt-action firearm in which is combined reliability and strength with ease of assembly, disassembly and low cost for manufacture.

Another object of the present invention is to provide a bolt-action firearm having a superior construction and arrangement of parts whereby the breech-bolt may be llaterally installed in and removed from a receiver.

A further object of the present invention is to provide a bolt-action firearm having a superior construction and arrangement of parts for controlling the action of the firing-member of the rearm.

Still another object is to provide a bolt-action firearm having a superior arrangement of parts for ejecting fired cartridges.

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 view in side elevation of a bolt-action firearm embodying the present invention: f

Fig. 2 is a broken view partly in vertical central-longitudinal section and partly in side elevation of the central portion of the firearm;

Fig. 3 is a similar view but showing some of the parts more fully in section;

Fig. 4 is a transverse sectional view taken on the line 4-4 of Fig. 3;

Fig, 5 is a view mainly in side elevation and partly in central section of the receiver together with the rear portion of the barrel;

Fig. 6 is a view in side elevation of the unit comprising the breech-bolt, the bolt-carrier and associated parts;

Fig. 'Z is a View thereof in front-end elevation but on a larger scale;

Fig. 8 is a top or plan view of the bolt-carrier detached, together with certain parts carried thereby:

Fig. 9 is a view in side elevation of the struc ture of Fig. 8;

Fig. 10 is a top or plan view of the breech-bolt detached, together with the parts carried thereby;

Fig. 11 is a view thereof in side elevation; and

Fia. 12 is a view thereof in front-end elevation but on a larger scale.

The particular bolt-action firearm herein chosen for purposes of illustrating one form of the present invent-ion, is of the automatic type, that is to say, the discharge of one cartridge effects the extraction and ejection of'the cartridge-case and causes the automatic insertion of a fresh cartridge. The firearm shown includes four major components, namely, a receiver 20, a barrel 2i, a stock 22 and a bolt-carrier 23.

The receiver 2@ is cylindrically contoured exteriorly and is formed in its right-hand side wall adjacent its forward end with an ejection opening 2d, and about midway of its length with a longitudinal clearance-notch 25, and adjacent its rear end with a clearance-recess 2t. 'I'he forward end of this said receiver 29 is interiorly threaded for the threaded connection of the exteriorly-threaded rear portion of the barrel 2i, which latter is provided with a usual cartridgechamber 2l.

Extending substantially throughout its length, the receiver 29 is formed with a laterallyor downwardly-opening bolt-receiving chamber 28 having its upper half cylindrically contoured to conform to the similarly-contoured upper half of a reciprocating breech-bolt 29,

The breech-bolt 29 is retained in place in the bolt-receiving chamber 28 of the receiver 20 by the bolt-carrier 23 before referred to. The main .portion of the bolt-carrier 23 projects slightly upwardly into the lower portion of the boltreceiving chamber 28 in the receiver 20 as is particularly well observable by reference to Figs. 3 and The bolt-carrier 23 above referred to, includes two substantially-corresponding and parallel side-plates 30 and 3i which are laterally spaced from each other to provide a central-longitudinal and vertical channel 32, by a rear spacingblock 33 and a front spacing-block 34. The upper portion of the rear spacing-block 33 projects above the Vupper surfaces of the respective side-plates 30 and 3l to form a head 35 which conforms in cross-sectional form to the transverse form of the bolt-receiving chamber 28 in the receiver 20. 'I'he said head 35 ofthe rear spacing-block 33 is formed with a rearwardlyprojecting coupling-extension 35 which fits into a coupling-recess 36a formed in the forward face of the rear wall 31 of the receiver 20. The said coupling-extension 36 overhangs a forwardlyextending coupling-lip 38 projecting forwardly from the lower portion of the said rear wall 31. As thus constructed, the said coupling-extension 36 and the coupling-lip 38 serve to normally prevent the downward movement of the rear portion of the bolt-carrier 23 with respect to the bolt-receiving chamber 28 in the receiver 20.

To releasably couple the forward portion of the bolt-carrier 23 to the receiver 2li, the front spacing-block 34 is for-med with a forwardlyopening recess or coupling-socket 39 which is adapted to receive the cylindrically-contoured rear end 40 of a coupling-screw 4l. The said coupling-screw di is threadedly mounted in a block-like stock-attaching lug l2 (Figs. 2 and 3) depending from the rear portion of the barrel 2l and flxedly attached thereto by means of a dovetail connection 53. y

Ihe stock-attaching lug d2 has vertically threaded into it, the threaded upper end of a stock-attaching scgrew it which extends upwardly from the under face of the stock 222 through an escutcheon 45 mounted therein. The said stock-attaching screw Mi serves to secure the forward portion of the stock 22 to the barrel 2l and hence to the, receiver 2U and its associated parts, with capacity for ready detachment.

As will be seen particularly well by reference to Figs. 4, '1 and l2, the breech-bolt 29 is formed on each of its respective opposite sides with one of two similar downwardly-facing longitudinal bearing-

surfaces

46 and 41 respectively adapted to ride upon the respective upper faces of the side-plates 30 and 3l of the bolt-carrier 23. At its rear the said breech-bolt 29 is formed with a depending longitudinally extending guide-lug 48 which ts into the upper portion of the channel 32 in the said bolt-carrier 23 to engage the respective inner faces of the side-plates 30 and 3| with a free sliding fit.

'Ihe breech-bolt 29 is provided with a longitudinal passage 49 in which reciprocates a firingplunger or firing-member 50 formed at its forward end with a firing-point l adapted to impinge against and re a cartridge in the cartridge-chamber 21 of the barrel 2| in the usual manner of rearms. In its upper face adjacent its rear end, the firing-plunger 50 is formed with a forwardly-facing cooking-abutment 52 which is adapted to be releasably engaged by a searnose 53 located at the forward end of a pivotal sear 54 shown particularly well in Fig. 3. The sear 54 is mounted for pivotal movement in a vertical plane upon a transverse Sear-pin 55 carried by and extending transversely of the head 35 of the rear spacing-block 33 across a recess 56 formed therein. The rear end ofthe sea-r 54 is 'pressed upwardly to effect the depression of its Sear-nose 53, by means of a helical Sear-spring 51 located in an upwardly-opening pocket 58 formed in the head 35 of the rear spacing-block 33. v

Intermediate the Sear-nose 53 and the searpin 55, the sear 54 is formed with a downwardlyf facing actuating-abutment 59 which is adapted to be engaged by the upper end of the body-por- -tion 60 of al T-shaped transmitting-member 6l.

The said transmitting-member 6I may be conveniently formed of sheet metal and is yieldingly pressed downwardly by a helical spring 62, as is especially well shown in Fig. 3. The said transmitting-member is mainly accommodated in a clearance-passage 63 formed in the head 35 and extending vertically from the recess 56 downwardly to and through to the under face of the rear spacing-block 33. Adjacent the lower end of its body-portion 60, the transmitting member 6l is formed with a, vertically-extending slot 64 through which extends a pin 65 mounted in the spacing-block 33 and serving to limit the vertical reciprocating movement of the said transmitting-member and to provide a fulcrum about which the same may rock.

The transmitting-member 6I in addition to its body-portion 60, includes a forwardly-extending finger 66 projecting from the said body-portion 30 about midway the heightl thereof and having its forward end beveled to provide a forwardlyand-upwardly-sloping cam-surface 61. The cam-surface 61 of the nger 665 is engageable by a similarly-sloping disconnecting-cam 68 formed at the rear end of a longitudinal clearance-passage 69 in the guide-lug 43 depending from the breech-bolt 29. When the breech-bolt 29 is moved rearwardly, the coaction of the cam 5t with the cam-surface 61 will rock the transmitting-member 6I in a counterclockwise direction to thus shift the upper end of the bodyportion 50 to the rear of the actuating-abutment 39 of the sear 54. With the parts thus shifted, the sear 54 cannot be released by the actuation of the trigger of the rearm.

The under edge of the body-portion 60 of the transmitting-member 6| is adapted to be engaged and lifted by the upper end of a triggerunit, generally designated by the reference character 10, and which includes a tubular-portion 1l from the lower end of which latter extends a ngerpiece 12 projecting below the under surface of the stock 22 and into a space defined by a trigger-guard 13 secured to the under face of the said stock. The main portion of the trigger 10 is accommodated in a vertical clearance-passage 14 formed in the stock 22 and intersected at its forward end by an upwardly-and-forwardlysloping passage 15 which, in turn, intersects at its forward upper end an upwardly-opening longitudinally-extending pocket 16 formed in the upper face of the stock 22.

The upper portion of the tubular portion 1l on the trigger 10 is provided with a forwardly-andupwardly-sloping arm 11 having its forward end extending around a pivot-pin 18 arranged crosswise of the stock 22 and carried thereby and constituting a fulcrum about which the trigger-unit 10 swings.

The tubular portion 1I of the trigger-unit 10 has passing therethrough a tubular magazinehousing 19 which also passes through the passage 15 in the stock 22 and has its open forward end entered .into the vertical and longitudinally-extending channel 32 in the bolt-carrier 23, as will be apparent by reference to Fig. 3 in particular. The said magazine-housing extends forwardly from the butt-end of the stock 22 and encloses a magazine-tube having a usual spring-pressed cartridge-follower 8l therein. The said cartridge-follower yieldingly presses forwardly upon the rearmost one of a column of cartridges which may be located in the said magazine-tube and also such of those cartridges as may be in process of being fed toward the cartridge-chamber 21.

Returning now to the breech-bolt 29 and the firing-plunger 50, it will be noted by reference to Fig. 3 in particular that the said firing-plunger is formed with an axial rearwardly-opening bore 82 receiving the forward portion of a helical ring-spring 83 thrusting at its forward end against the end wall of the bore 92 in the saidfiring-plunger. At its rear end, the firing-spring 30 encircles the relatively-slender forward portion of a spring-guiding plunger 86 seated at its rear end against the forward face of the head 8F of the rear spacing-block 33. The said plunger 9d is formed with a forwardly-facing spring-seat 85 against which is seated the rear end of the firing-spring 83. The said spring-guiding plunger 3d together with the rear portion of the iiringspring S3 is adapted to be telescopically received in the bore 02 in the firing-plunger when the latter is moved rearwardly from the position in which it is shown in Fig. 3.

For the purpose of yieldingly urging the breech-bolt 29 forwardly into its breech-closing position, a helical breech-closing spring d5 is provided, the forward portion of which is housed in a bore 96a formed in the said breech-bolt. The

said spring 95 presses at its forward end against the end wall ofthe bore 83a in the breech-bolt 2 9, as shown in Fig. 10. The said breech-closing spring 8a encircles a. spring-guiding plunger 3l which at its rear end, like the rear end of the breech-closing spring 86, presses against the front face of the head 35 of the rear spacingblock 33.

For the purpose of locking the transmittingmember 0| against upward movement to operate the sear 36 and thus release the firing-plunger 50, a safety-lock is provided which comprises a cylindrical stem 98 and a lever-like ngerpiece 89. The said stem 88 extends transversely across the rear portion of the bolt-carrier 23and is lournaled therein for oscillating movement while the iingerpiece 0 extends above the adjacent portion of the stock 22 and is accommodated in the sha1- low clearance-recess 20 before described in the right side face of the receiver 20 near the rear end thereof. At a point in line with the bodyportion t0 of the transmitting-member 6|, the stem 88 of the safety-lock is formed with a clearance-notch 9@ which normally permits the free vertical reciprocation of the transmitting-member 3l when said stem is in the position in which it is indicated in Fig. 3 and its ngerpiece 89 is in the position in which it is shown by full lines in Figs. l and 2. When, however, the iingerpiece Bil is turned rearwardly into the position in which it is indicated by broken lines in Fig. 2, the stem 33 will be similarly turned in a counterclockwisev direction to thereby extend a portion of the said stem into the upward path of movement of the stop-shoulder 9| of the transmitting-member 8|, to thus prevent the upward lifting movement of the said transmitting-member by the triggerunit l0. In this manner the rearm is rendered safe since it cannot be discharged under the conditions just referred to.

Installed in the forward portion of the channel 32 in the bolt-carrier 23, is a group of parts constituting what is commonly referred to in the art as a magazine-throat and related parts, as will now be described.

The magazine-throat above referred to, includes two laterally-spaced apart complementa] side-plates 92 and 33 (Fig. 8) respectively located against the respective inner faces of the sideplates 30 and 3| of the bolt-carrier 23.

Rigidly mounted between the upper rear portions of the respective side-plates 92 and v93 of the magazine-throat, is a cut-oil carrier 95 secured to the bolt-carrier 23 by any suitable means such, for instance, as transverse pins 95-99 The said cut-oir carrier 94 accommodates a pivotal cartridge cut-oir 98 which is pivotally con nected at its rear end to the said carrier 94 by means of a transverse-pin Sl as may be clearly seen by reference to Fig. 3.

Located laterally intermediate and extending parallel with the eide-

plates

92 and 93 of the magazine-throat, is a cartridge-elevating plate 93 having substantially the shape of a right-angle triangle and having its hypothenuse sloping upwardly and forwardly away from the open end oi the magazine-tube 8i? in substantial parallelism therewith. The said cartridge-elevating plate 98 is secured in place by lateral pins 99-99 Iwhich also extend into the side-plates and 3| of the bolt-carrier 23.

The cartridge cut-oil` Q0, above referred to, is formed at its forward end with an actuatingnose |00 which is adapted to project upwardly through a clearance-opening H08 in the cut-oi carrier @il for engagement with the underside of the breech-bolt 29 for entry on occasion into a clearance-notch |02 formed in the underside of the said breech-bolt, as shown particularly well in Fig. 3.

'I'he cartridge cut-oil? 96 is formed about mid- .way of its length on its underside with a downwardly-projecting cartridge-stopping finger |03 which is adapted to be sequentially engaged by the forward face of the rims |04 of cartridges such as |05, |05 and |01 shown in Fig. 3, and also the rims of such other cartridges as may be included in a column of cartridges, as the same, in turn, pass out of the lforward end of the magazine-tube 30.

The rear spacing-block 33, before referred to, is rigidly organized with the side-plates 30 and. 3| of the bolt-carrier 23 by two (more or less) transverse coupling-pins |08 and |09, as is shown in the drawings. Similarly, the front spacingblock 34 is rigidly organized with the said sideplates 30 and 3| by means of coupling-pins H0 and il i, as is shown particularly well in Figs. 3, 6 and 9.

Immediately below the integral rear wall 31 of the receiver 20, the stock 22 has extending thereacross a stock-attaching pin ||2 which is adapted to t in a rearwardly-opening transverseV stock-attaching notch H3 formed in the lower portion of the rear spacing-block 33 of the boltcarrier 23.

Secured `to the left-hand side-plate 3| of the bolt-carrier 33 is a cartridge-ejector H4 of L- shaped form in cross-section and comprising a vertical leg H5 and a substantially-horizontal ange-like leg l i6. The vertical leg of the said cartrdige-eiector is suitably recessed into a ver tical groove provided in the outer face of the side-plate 3|, and the horizontal leg H6 thereof projects inwardly toward the center oi the breech-bolt 29. rl'he breech-bolt 29 is provided in its left-hand side-wall with a longitudinal clearance-groove ill for the accommodation of the said horizontal leg H5 of the cartridge-ejector iM. Adjacent its rear end, the horizontal leg H6 of the-cartridge-ejector il is provided with a forwardly-facing rejecting-abutment M3 which is adapted to be engaged by the rear faces of empty cartridges-cases as the same are pulled rearwardly by means of an extractor H9 carried at the forward end of the breech-bolt 29.

The breech-bolt 20 may be moved rearwardly by the force exerted by the ring of a cartridge, or the said breech-bolt may be manually moved rearwardly by means of a bolt-handle |20 projecting from its right side wall and accommodated in the clearance-notch 25 in the side wall of the receiver 20.

Beyond the functions above indicated for the various parts, it is unnecessary to describe in detail the operation of the firearm other than phases thereof with which the present invention is mainly concerned.

As has before been pointed out, the breechbolt 29 is retained in place against downward displacement within the hollow receiver 20 by the bolt-carrier 23, which latter provides convenient and accurate bearing-surfaces for guiding the said breech-bolt in its reciprocating movements.

Should lt be desired for any reason to remove the breech-bolt 29 fromY the receiver 20, the stock 22 is first detached by unscrewing the stockattaching screw M from the stock-attaching lug i2 depending from the barrel 2|, and then rocking the said stock with respect to the still unitary receiver 20, barrel 2l, and bolt-carrier 23, about the stock-attaching pin II2 as a center. When the parts have been sufficiently rocked, the stock 22, together with its stock-attaching pin H2, may be drawn rearwardly so as to disengage the said stock-attaching pin from the stockattaching notch H3 in the rear face of the rear spacing-block 33.

The next step in demounting the firearm 'may be accomplished by backing the rear en'd 40 o f the coupling-screw 4I out of the coupling-socket 39 in the front spacing-block 34 of the bolt-carrier 23. The forward end of the bolt-carrier 23 may now be rocked downwardly with respect to the receiver 20 and the barrel 2|, until the said front end is completely withdrawnr from the downwardly-opening bolt-receiving chamber 28 in the said receiver 20. The bolt-carrier may now be slid forwardly along a downwardly-inclined path until the under face of the couplingextension 36 of the head 35 of the rear spacingblock 33 clears the coupling-lip 38 extending forwardly from the lower edge of the rear wall 31 of the receiver 20. In this manner, the entire assembly illustrated particularly well in Figs. 6 and 7 may be removed as a Whole from the receiver 20. The breech-bolt and its associated parts may now be removed as a unit from the bolt-carrier 23, so that the said breech-bolt and associated parts assume the appearance shown in Figs. and 11, and the bolt-carrier 23 and associated parts present the appearance shown in Figs. 8 and 9.

To re-assemble the rearm, the steps above described may "be reversed, as will be obvious.

By the construction and organization of parts above described, the rear portion of the receiver 20 may be made solid and integral, to thus provide maximum strength and the breech-bolt 29 firmly held in place in the said receiver and accurately guided by the bolt-carrier 23, thus minimizing complex machining operations within the said receiver 20 and permitting an entire assembly, such as illustrated in Figs. 6 and 7, to be assembled together and tested prior to their introduction into the relatively inaccessible interior of the receiver 20.

Furthermore, by organizing the cartridgeejector H4 with the bolt-carrier 23 or its equivalent, an extremely rugged ejector may be provided which will withstand continued hard usage without derangement.

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 Yin allV `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 bolt-action firearm including in combination: a receiver having a laterally-opening bolt-receiving chamber; a breech-bolt having a longitudinal clearance-groove and reciprocatable in the bolt-receiving chamber `of the said receiver; a removable bolt-carrier having a guideway along which the said breech-bolt slides and removably secured to the said receiver in position to hold the said breech-bolt in the bolt-receiving chamber of the said receiver and to guide the said breech-bolt for movement therein; and a cartridge-ejector of L-shaped form having one leg attached to the said bolt-carrier and having a second leg fitting into the longitudinal clearance-groove in' the said breech-bolt.

2. A bolt-action rearm including in combination: a receiver having a downwardly-opening bolt-receiving chamber and a substantiallyclosed rear Wall; a breech-bolt reciprocatably mounted in the bolt-receiving chamber of the said receiver and dimensioned to be laterally introducedinto and removed therefrom; a removable bolt-carrier comprising a pair of laterallyspaced-apart side-plates, each having an upwardly-facing guideway for the said breech-bolt, and providing between them a vertical channel through which cartridges may be fed, a spacingblock projecting upwardly from the rear portion of the said side-plates into position to be interposed between the rear end of the said breechbolt and the rear wall of the said receiver, the said bolt-carrier being removably secured to -the said receiver in position to hold the said breechbolt in the bolt-receiving chamber of the said receiver; and a cartridge-ejector carried by one of thev side-plates of the said bolt-carrier and removable from the said receiver as a unit with the said bolt-carrier.

CARL G. SWEBILIUS.