US2845740A

US2845740A - Integral barrel lock and extractor

Info

Publication number: US2845740A
Application number: US472633A
Authority: US
Inventors: Ernest P Simmons
Original assignee: Olin Corp
Current assignee: Olin Corp
Priority date: 1954-12-02
Filing date: 1954-12-02
Publication date: 1958-08-05
Anticipated expiration: 1975-08-05

Description

Aug. 5, 1958 E. P. SIMMONS INTEGRAL BARREL LOCK AND EXTRACTOR 2 Sheets-Sheet 1 Filed Dec. 2. 1954 A ffn/weya.

Aug. 5, 1958 E. P. SIMMONS 2,845,740

INTEGRAL BARREL LOCK AND EXTRACTOR Filed Dec. 2. 1954 2 Sheets-Sheet 2 E W [mi INVENTOR. [mwf x? Jim/2mm BY Affa/weyx x3 wwww 3 Q ww svw etfectzon the ejection action of the gun.

United States Patent" 2,845,740 INTEGRAL BARREL LOCK AND EXTRACTOR Ernest P. Simmons, Kansas City, Kans., assignor to Olin ,Mathieson Chemical Corporation, a corporation of December'2, 1954, Serial No. 472,633

- Application 2 Claim or. 42-75 iThisinvention relates to new and useful improvements in automatic shotguns, and has particular reference to a safety device preventing the removal of the barrel of an automatic shotgun of the split-chamber type when there is a shell in firing position in the chamber.

' f'In automatic shotguns of the split-chamber type, the chamber, instead of being formed in the breech end of-the barrel itself, is formed in a separate chamber member carried by the receiver. This chamber member, when the gun is in firing position, is locked into the receiver by means entirely independent from the connection of the barrel into the receiver. Thus when vin the ordinary dismantling of the gun for storage the barrel is detached from the receiver, it is entirely possible that a shell may be left in the chamber in position for firing. This is of course extremelydangerous, in that the gunmay subsequently be accidentally discharged by I jarring or by careless handling during storage, or when next reassembling' the gun.

The prime object of this invention is the provision of a very simple andeconomical means which absolutely prevents this occurrence, ands which requires thatthe shell in the chamber be removed,

or at least that the bolt be moved to a-non fiiing'position, before the'barrel can be detached from the receiver.

This object is accomplished in general by'the provision of a locking member attached to the bolt of the gun and projecting forwardly sufiiciently far, when the bolt is closed for firing, to engage in a notch formed in the breech end of the barrel. The barrel'is thus locked against rotation, andthereby against removal from-the receiver, since this removal requires at least a partial rotation of the barrel. When the bolt isretracted man-' ually, thelockingmember is withdrawn from the barrel notch and the barrel may be removed, but at the same a are of the bayonet type, only the opposite quadrants v the forward'end of said tube.

prevented from rotating by a connection thereof, not ,7 shown, to tube 24, such as a radial arm fixed to the barthe barrel.

extension 36 having the "form generally of a downwardly opening semi-cylinder. The rearwardjend of said ex tension terminates in spaced relation to a forwardly facing where thegunners stand abreast, and shells ejected from one vshooters gun often strike adjacent shooters.

Other objects. are simplicity and economy ofconstruction,.efliciency anddependability of operation,'and adaptability to be incorporated in pro-existing guns with a minimum amount of alteration.

With these objects in view, as well as other objects whichwill appear in course of the specification, reference will. be had to the drawing, wherein:

Fig. 1 is a longitudinal.mid-sectional view of the re-- ceiver and adjacent portions of anautomatic shotgun embodying the, present invention, with parts left in elevation. Fig. 2 is a fragmentary viewsimilar to-Fig; 1, with additional parts. left in elevation. 1

the rearward end of the shell in the'chamber, as shown Fig. 3 is a slightly irregular sectional view taken on line III.III of Fig. 1, with parts left in elevation.

Fig. 4 is a sectional view taken on line IV-IV of Fig. 1. s Fig. 5 is a sectional view taken on with parts left in elevation.

Fig. 6 is a sectional view taken on line VIVI of Fig. 2, with partsleft in elevation.

Like reference numerals apply to similar parts through: 1 out the several views, and the numeral 2 applies -to the receiver portion of an automatic shotgun of the split: chamber type, said receiver being hollow and elongated longitudinally of the gun and having right and left side walls 4 and 6, top wall 8, front wall 10, rear wall 12,

and being open at the bottom. The rearward portion of the bottom opening is closed by a trigger frame 14 held in the receiver by an assembly pin 16. The forward portion of the bottom opening is occupied by a shell carrier 18 carried movably by frame 14. Said shell carrier forms no part of the present invention, but its function will be described generally below.

The. gun barrel 20 is threaded into a bore 22 formed through the front wall 10 of the receiver, and communicates with the interior of the receiver. The threads of this connection may be standard, but more commonly of the barrel and bore 22 being threaded, as indicated in Fig, 6. In assembling, the barrel threads maybe insertedaxially to their full depth into the receiver bore 22, and the barrel then rotated deg."t o bring the' A magazine tube 24 is dis posed beneathiand parallel to the barrel, and is also.

threads into engagement.

threaded at its rearward end into front wall 10 ofthe receiver in communicating relation with the interior of Shells 26 carried in said magazine tube said receiver. are urged rearwardly by a spring, not shown, carried in The barrel is normally rel and detachably connected to tube 24.

Carried for longitudinal sliding movement in the 'rear- 1 ward end portion of the barrel isa tubular shell chamber 28 adapted to receive a shell 26 therein as best shown-in Figs. 1 and 3. .Said chamber is provided at its rearward end withan internal shoulder 30 against which the rim '32 of the shell abuts, and an external shoulder 34 which normallyabuts the rearward end of The chamber is provided with a rearward shoulder 38 formed internally in-receiver 2. As best shown in Figs. 1 and 3, a pin 40 is carried slidably in a: bore 42 formed in the wall of said extension, and isv urged rearwardly against shoulder. 38 by a compression spring 44 carried in said bore. The chamber shoulder 34 is'thus urged forwardly atall times toward engagement with the rearward end of the barrel.

The bolt 46, when the gun-is closed, is disposed within chamber extension 36, the forwardend thereof abutting in Figs. 1 and 3. Adjacent its rearward end, said bolt is provided with an u'pwardly projecting lug 48, which projects into a slot 50 formed in the upper wall of chamber 1 extension 36, whereby to lock the bolt against rearward :rnovement relative to the extension. The bolt is positively secured against any further forward movement in the receiver by the engagement of a depending lug 52 (Fig. 1) integral with the bolt against the inner: face 5 of the front wall 10 of the receiver. The mating surfacesof lug 48 and slot 50 are inclined whereby to pi'ovide a cam' action forcing the "bolt firmly forward againsttheff Patented .Aug. 5, .1958

line v-v of Fig. 1,

.a matching shoulder of the bolt.

shell when the'bolt is moved upwardly. The bolt carries'a firing pin 54 therein. Said firing pin is urged rearwardly in said bolt against af stop pin 56 by a spring 58, sothat the forward end thereof is disposed rear-wardly of "the" forward end-of'the bolt, andth'e -rearwardend thereof projects rearwardly from the-back end of the bolt. is-urged pivotally forwardly by spring 64 to strike the rearward end of the firing pin to drive it forwardly to detonate the shell in the chamber in the usual manner. Said'hammer is normally retained in its cocked position by the engagement in a notch 66 thereof of the toe 68 of a trigger 70 pivoted in frame 14 at 72. When the trigger'is pulled rearwardly against the pressure of trigger spring 94, the toe thereof is disengaged from the hammer notch 66, and the hammer'functions as described.

Thebo'lt also carries an ejector pin 76 for longitudinal movement in approximately parallel relation to but spaced transversely apart from the firing pin. The ejector pin is urged rearwardly in the bolt by a spring 78 carried in thebolt, whereby a shoulder 88 (Fig. 3) thereof engages In this position the Iorward end of the ejector pin is retracted within the bolt, and the rearward end projects outwardly from the rearward end of the bolt.

The bolt also carries an extractor 82 comprising a generally L-shaped lever having one arm 84 pivoted in the bolt on a vertical pivot pin 86 and projecting outwardly from said bolt transversely of the gun, as best shown'in Fig. 3, and a right angled arm 88 extending forwardly along the side of the bolt to a point ahead of the forward end of the bolt. The extractor arm 88 is urged resiliently toward the bolt by a spring 90 carri'ed in-the bolt. Ann 88 extends forwardly through a notch 92 formed through the rim of the chamber 28 between shoulders 30 and 34 thereof. Said arm is provided at its forward end with a tooth 94 which engages the forward edge of the rim 32 of the shell in the charnber (Fig; 3). Extractor arm 88 is provided with a forward extension 96 which, when the bolt is closed, projects into a'notch 98 formed in the external surface of the rearward end of barrel 20. The function of the extractor and extractor extension will be fully described below.

The bolt is supported in the receiver by a horizontal pin 100 extending transversely of the gun and passing through a pair of matching slots 102 formed in a pair of side walls 104 and 106 which are integral with and depend from the bolt. The forward end portions of said slots, in which pin 100 is disposed when the bolt is closed, are substantially horizontal. The rearward portions of said slots are inclined upwardly and rearwardly, for a purpose which will appear. Pin 100 extends outwardly from the sides of the bolt, and the ends thereof are mounted in slides 108 and 110. Said slides are mounted for forward and rearward sliding movement respectively in grooves 112 and 114 formed in the inner surfaces of receiver walls 4 and 6 (Fig. 4). The right slide 108 is provided with a thumb-piece 116 which projects outwardly through a slot 118 formed in receiver wall 4, whereby said slide may be operated manually. Said slot is upwardly enlarged as at 120 to form an opening through which shells may be ejected.

A link 122 is pivoted on pin 100 between bolt side walls 104 and 106, and extends rearwardly through the receiver. Hammer 60 operates through a longitudinal slot 124 formed in said link. At its rearward end, said link is pivoted at 126 to an inertia rod 128 which is carried for longitudinal sliding movement in a tubular extension 130 of the receiver, said extension being disposed in the stock 132' of the gun. A recoil spring, not shown, is disposed in tube 130 behind rod 128, and urges said rod forwardly.

The general operation of the gun is as follows: When thegun fired as previously described, the chamber A hammer 60 pivoted in triggerfrarne 14 at 62 28, extension 36, and bolt 46 first recoils rearwardly as a unit against the pressure of spring loaded pin 40, since the bolt is locked in the chamber extension. The bolt motion is also transmitted through pin and link 122 to inertia rod 128, imparting substantial momentum thereto. The rearward movement of the chamber is arrested after a short travel by the engagement of the rearward end of extension 36 with receiver shoulder 38, but inertia rod 128 continues rearwardly by its momentum, carrying pin 100 rearwardly in bolt slots 102. When pin-100 engages the inclined rearward portions of said slots, it cams the rearward end of the boltdownwardly, lowering bolt lug 48 from the slot 50 of the chamber extension. The momentum of inertia rod 128 then carries the bolt rearwardly independently of the chamber. During this movement, the extractor tooth 94, which is in engagement with the rim 32 of the expended shell in the chamber, pulls the shell out of the the receiver, the rearward end of ejector pin 76 engages and is arrested by rear wall 12 of the receiver,-

thus forcing. said ejector forwardly with respect to the bolt, against the pressure of ejector spring 78, as the bolt continues its rearward movement. The forward end of the ejector pin is thus projected through the forward end of the bolt into engagement with the shell, thereby pivotingit around extractor tooth'94 and throwing it outwardly through ejection opening 120 of the receiver. The bolt is then ready to start its forward movement under the urging of the recoil spring. During its rearward movement a new shell 26 was ejected from the magazine tube 24 by the magazine spring onto shell carrier 18. As the bolt startsits forward movement, it engages a suitable mechanism (not shown) carried by trigge'r frame 14 and operable to flip shell carrier 18 upwardly to move the shell carried thereby into the path of the bolt. The bolt then continues forwardly to its locked position, pushingthe shell into chamber 28.

While the above description of operation is some what incomplete andsketchy, it is believed suflicient to illustrate the operation of the barrel locking mechanism. It is apparent that when the bolt is closed'and locked, as shown in Figs. 1 and 3, extension 96 of extractor 82 is engaged in notch 98 of the barrel, thereby locking the barrel against rotation and preventing the removal thereof from the receiver. To remove the barrel, the operator must first pull thumb-piece 116 rearwardly, thereby moving pin 100 and slides 108 and rearwardly, sufliciently far to cause pin 100 to cam the bolt downwardly to unlocklug 48 thereof from chamber extension slot 50'as previously described, and still further to move the bolt rearwardly with respect to the chamber. The bolt movement pulls the extractor extension rearwardly from barrel notch 98, and the barrel may then berotated and removed.

While only a short bolt movement is required to free the barrel, it is contemplated that the operator, ifhe attempts to remove the barrel and finds it locked, will be reminded-that there may be a live shell in the chamber and will hence pull the bolt back not only far enough to freethe barrel, but all the way back to eject the shell. However, if he does pull the bolt back only far enough to free the barrel and not far enough to eject the shell, the-gun will still remain safe. When the barrel is removed, the'chamber is urged forwardly by pin 40 and spring 44 to such a'point that bolt lug 48 cannot enter slot 50 of the chamber extension, but strikes the inner extractor will afiect the normal ejection action of the gun, since the shell as it is ejected strikes against the extension. Its efiect is to substantially reduce the distance the shell is thrown. This is considered an advantage particularly in match shooting, wherein the gunners often stand abreast on a firing line and are quite often struck by shells ejected from the guns of those adjacent in line.

While I have shown and described a specific'embodiment of my invention, it will be readily apparent that many minor changes ofstructure and operation could be made without departing from the spirit of the invention as defined bythe scope of the appended claims.

What I claim as new and 'desireto protect by Letters Patent is:

1. In an automatic shotgun, a receiver, a barrel secured at is rearward end in said receiver by a rotatably detachable connection, a tubular chamber disposed slidably in the rearward portionof the barrel and extending into the receiver, said chamber being operable to receive a shots-hell and having an internal shoulder for engaging the rim of the shell, said chamber shoulder being formed with a first notch, a bolt slidably disposed within the 7 receiver, means operative to lock the bolt in a battery position in the extension of said chamber whereby the forward end of the bolt abuts the head of said shell, and

a locking member pivotally mounted to the bolt and received by said first notch and extending forwardly to engage a second notch formed in the rear end of i the barrel effective to lock the barrel to the chamber.

2. The structure set forth in claim 1 wherein the bolt carries a pivotally mounted extractor comprising an arm secured to the bolt and extending forwardly therefrom past the edge of said shell rim and being provided with a tooth operable to engage said shell rim to extract the shell from the chamber when the bolt. is moved away from its battery position, said locking member comprising a forward extension of the extractor arm.