US2715290A - Magazine for automatic firearms - Google Patents

Description

Aug. 16, 1955 E. M. HARVEY MAGAZINE FOR AUTOMATIC FIREARMS Filed April 2 1949 1 4,1 61 I ,1 i 3. z :1.

Jwuonfm nite tats MAGAZINE FOR AUTOMATIC FIREARMS Earle M. Harvey, Agawam, Mass., assignor to the United States of America as represented by the Secretary of War The invention described in the specification and claim may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.

This invention relates to improvements in firearm magazines of the type wherein a staggered group or stack of cartridges is arranged to be automatically fed one by one into the chamber of the firearm by means of a forwardly moving bolt.

In modern automatic rifles, every effort is being directed toward neutralizing the recoil of the weapon by the use of such attachments as muzzle brakes or recoil checks. Although extremely beneficial in most cases, the aforementioned devices do not entirely eliminate the recoil inherent in an automatic firearm. In fact, it has been found that with cartridge magazines of the type herein disclosed, the existing recoil movement of the firearm, and consequently of the attached magazine, is of suflicient magnitude to drive the noses of the cartridges against the front wall of the magazine case which thereby tends to become mutilated especially during sustained automatic firing. Inasmuch as the front end of a conventional magazine follower contacts this wall as such follower is being forced upwardly by the follower spring, it is important that the wall present a smooth guiding surface.

Accordingly, it is an object of this invention to provide means for maintaining in a magazine a smooth front wall guiding surface for a vertically movable follower despite the mutilation frequently caused by the tips of the bullets as a result of the combination of magazine recoil and relative inertia of the cartridges.

Another problem encountered in high speed automatic firearms which employ a fixed box-type magazine is the possibility of relative movement between the cartridges therein and the walls of the magazine itself. The normal recoil movement of the firearm, and consequently of the magazine fixed thereto, plus the relative inertia of the spring-biased follower and cartridges thereon combine to produce a downward movement of the follower in relation to the magazine walls. Such condition is apt to occur to a much greater degree when the firearm is provided with an efiicient muzzle brake or recoil check which introduces an appreciable counter-recoil action in opposition to the normal recoil movement. As a result, the cartridges have been known to separate from one another and be canted laterally to such extent that feeding jams have occurred.

It is therefore another object of this invention to provide definite means in a magazine for preventing lateral displacement of a staggered group of cartridges in the event of downward vertical movement thereof relative to the walls of the magazine.

Magazines of the type herewith concerned are customarily provided with a spring-biased follower which, after the last round has been fired, serves to obstruct the firearm bolt and retain it in the open and recoiled position. It is necessary therefore that the bolt have suffi- 2,715,29 Patented Aug. 16, 1955 "ice cient overtravel on recoil to allow the follower time to spring up in front thereof. Accordingly, a further object of this invention contemplates a quicker movement of the follower to a bolt-obstructing position in order to decrease the amount of recoil travel necessary for the bolt.

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

Fig. l is a right side elevational view showing the magazine of this invention latched to a firearm;

Fig. 2 is a fragmentary cross-sectional view taken along the line 22 in Fig. 1';

Fig. 3 is a fragmentary view showing the follower in a bolt-obstructing position;

Fig. 4 is a front elevational view of the follower with the magazine shown in dotted lines;

Fig. 5 is a bottom view of the magazine showing the floor plate secured thereto; and

Fig. 6 is a top view of the magazine showing the position of the cartridges therein.

Although here shown and described as a box-type magazine adapted for use with the automatic firearm disclosed in my copending application Serial No. 75,921 dated February 11, 1949, it should be understood that the unique features proposed therefor are equally applicable to any type of magazine and automatic firearm which is subject to the pro lerns previously discussed.

In Fig. 1 there is shown a box-type magazine 5 having side walls 6, a front end wall 7, a rear end wall 8, and a floor plate 9. Within magazine 5 there is provided a spring 13 arranged to bias upwardly a follower 11 upon which cartridges l2 normally rest in a double column staggered group. Spring 1th is suitably secured at one end to the underside of follower 11 and is retained at the other end by the magazine floor plate 9.

Magazine 5 is of the conventional box-type construction with cartridge holding lips as shown at 19 and is latched to the firearm by means of a pivoting arm member 22 engaged in a suitable recess 23 formed in the side of magazine 5 as shown in Fig. 2. According to the requirements of this invention, magazine 5 is provided with a vertical rib 13 suitably secured thereto, as by welding or riveting, which extends centrally along the interior of the length of the front end wall 7 for a purpose to be shown.

Follower 11 is here shown as a unitary member provided with a rearwardly extending lug 14 arranged to retain the firearm bolt 15 in the open position after the last cartridge has been fired. The rear end wall 8 of magazine 5 is constructed with a channel 16 designed to permit passage of lug 14 during the vertical movement of follower 11. The front end of follower 11 is bent over downwardly and arcuately in a plane parallel to end wall 7 as shown at 20 in Fig. 1 and is provided with a V-shaped opening 17 arranged to straddle rib 13 when the rear end of follower 11 is pivoted downwardly. The rear end of follower 11 is similarly bent over as shown at 21.

The improvement to follower 11 consists of a pair of upstanding ears 18 formed adjacent the front end as shown in Fig. 1.

As previously explained, the inertia of cartridges 12 often causes the tips of the bullets to mutilate the front end wall 7 of magazine 5 during sustained automatic fire. However, by locating the vertical rib 13 of this invention centrally along the length of front end wall 7 so as to lie between the double column of staggered cartridges 12, there is here provided a smooth guiding surface which can not come in contact with the tips of the bullets and thereby become marred. As a result, the possibility of feeding jams due to the front end 20 of follower 11 catching on a rough surface of end wall 7 is eliminated through the provision of rib 13.

Furthermore, since the tips of the bullets lie beyond the face of rib 13, the possibility of lateral displacement of the cartridges is also eliminated. The sides of rib 13 serve to keep cartridges 12 in a double column staggered group at all times regardless of any floating which may occur between follower 11 and the underside of cartridge lips 19 as a result of the combined action of firearm recoil and counter-recoil due to an attachment such as a muzzle brake or recoil check.

When the last round has been fired, the recoil movement of bolt 15 imparts a pivoting movement to follower 11 by allowing the front end thereof to be biased upwardly first so that ears 18 contact the overhanging cartridge holding lips 19 at the mouth of magazine 5. Consequently, as bolt 15 rides ofI of lug 14, the foregoing pivoted position of follower 11 will cause lug 14 to snap up smartly in front of bolt 15. It can thus readily be seen that a pivoted movement of this type permits faster action of follower 11 than the conventional action where the entire follower must be biased upwardly with both ends in the same longitudinal plane. As a result, the overtravel of bolt 15 on recoil can be appreciably reduced thereby permitting a desirable increase in the rate of fire. Moreover, a shorter bolt travel would allow some reduction in the size and the related components (not shown) a feature which introduces a much sought after corresponding reduction in weight for the entire firearm.

Thus, with a magazine constructed in accordance with 30 this invention, a more positive feeding action is provided and one which is not subject to the jams normally encountered in high rate automatic weapons of the type herewith concerned.

I claim:

In a firearm magazine for holding a plurality of cartridges in a double column staggered group, the combination of, a pair of vertical side walls, a floor plate, a front and rear end wall cooperating with said side walls to form an opening at the top for passage of the cartridges, a vertically extending rectangular rib centrally disposed along the interior face of said front end wall and projecting rearwardly therefrom so as to lie slightly beyond the front ends of the cartridges, and a springbiased freely movable follower longitudinally disposed between said side walls for vertical movement during feeding and loading of the cartridges, said follower having a bent-over downwardly projecting arcuate front end portion arranged to normally bear against said vertical rib, said front end portion having an inverted V-shaped notch therethrough whereby the lower extremities thereof formed by said notch straddle said rib in order to permit tilting of said follower about the point of contact thereof with said rib.

References Cited in the file of this patent UNITED STATES PATENTS 616,261 Roth Dec. 20, 1898 804,984 Searle Nov. 21, 1905 885,868 Savage Apr. 28, 1908 1,462,972 Lewis July 24, 1923 1,858,862 Loomis May 17, 1932 2,081,235 Hillyard May 25, 1937 FOREIGN PATENTS 192,698 Germany Nov. 12, 1907 569,280 Germany Feb. 1, 1933

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