US2436937A - Shell ejecting mechanism for machine guns - Google Patents

Description

March 2, 1948. F. x. RATAICZAK SHELL EJECTING MECHANISM FOR MACHINE GNS Filed May 2.3, 1945 2 sheets-sheet 1 E N 9 f. 1 A t n. om .1 \v^ n m 9v o wm um v 4 Qi fnv 4 March 2, 1948.

Y1.-. l. RATAICZAKi SHELL EJECTING MECHANISM FOR MAHINE GUNS Filed May 25;"1945 2 sheets-sheet 2 `INVENTOR.

Patented Mar. 2, 1948 SHELL EJECTING MECHANISM FOR MACHINE GUNS Francis I. Rataczak, Dayton,

General Motors Corporation, Dayton, corporation of Delaware Ohio, assignorl to h10, a

Application May 23, 1945, Serial No. 595,265

(Cl. l12-25) 10 onim's.

This invention relates to ordnance and more particularly to an improved shell ejecting mechanism for use in a machine gun.

The invention set forth herein represents an improvement over the mechanism set forth in my co-pending applications Serial Nos. 536,229 and 565,252 filed May 19, 1944 and November 27, 1944, respectively, The latter application has matlired into Patent No. 2,411,979 of December 3,

It is an object of this invention to provide a rugged shell ejecting mechanism capable of electing empty shells from a high speed machine gun without damaging or breaking away fragments of the rims of the shells.

Another object of this invention is to provide an improved shell ejecting mechanism which is inexpensive and trouble-free.

Another object of this invention is to provide an improved arrangement for supporting the shell ejecting mechanism relative to the rest of the gun parts. Y Y

Still another object of this invention is to provide an improved shell ej ecting mechanism which can be used in existing guns without making any major changes in the gun construction which has otherwise proven to bel Very satisfactory.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a fragmentary view, partly in section, showing the arrangement of my improved shell ejecting mechanism relative to the rest of the gun parts;

Fig. 2 is a fragmentary View, with parts broken away, showing a shell being ejected by my improved shell ejecting mechanism; i

Fig. 3 is a fragmentary elevational view yof the shell ejector and the feedway which has been superimposed upon a diagrammatic showing of the receiver and the receiver housing;

Fig. 4 is a fragmentary sectional view taken substantially on line 4-4 of Fig. 5 showing the relationship of the shell ejecting mechanisrnrelative to the feedway and the cover;

Fig. 5 is a top view showing the relationship of the shell ejecting mechanism to the conventional feedway; and

Fig, 6 is a fragmentary view on an enlarged scale showing the relationship of the shell to the shell ejecting cam when the shell first engages the `cam.

Referring now to the drawings, reference numorals III, I2 and I4 designate the receiver housing, the cover, andthe gun barrel, respectively. As set forth more fully in my co-pending applications, the shells are fed into the gun on a feedway I6 which is hel-din place between the receiver I9 and the cover I2. The bolt mechanism comprises a main portion I5 and a bolt head I'I both of which are mounted for reciprocation within the receiver I0 in accordancewith present practice. The bolt head I'I is provided 'with a conventional type of extractor I8 which serves to extract the empty shells from the barrel I4 as the bolt and bolt head move to the rear upon recoil. As best shown in Fig. 2, the empty shell 20 strikes against a shell ejecting cam 22 which is carried by and actually formed as an integral part of the mounting bar 24 as shown in Figs. 3, 4 and 5. The shell ejecting cam 22 is yieldably mounted so as to provide for movement of the cam relative to the bolt head, the cover and the rest of the gun elements. The ejected shells leave through the ejection opening 21 in the bottom of the receiver I9.

As best shown in Figs. 3 and 5, the mounting lbar 24 is loosely or adjustably supported by means of studs 25 rigidly carried by the end wall 28 of the conventional feedway i6. The mounting har 24 is provided with elongated slots 30 through which the studs 25 project so as to guide and limit the movement of the mounting bar 24. The relationship of the mounting bar 24, the shell ejecting cam 22 and the feedway I6 is shown in Fig, 5 wherein a portion of the'end wall 29 which is directly above the cam 22, has been broken away to facilitate illustration. As best shown in Figs. 4 and 5, holes 34 have been drilled into the front face of the mounting bar 24 for the reception of spring means 3B as shown. The springs 36 serve to bias the mounting bar24 away from the rear wall 28 of the feedway I5. Referring now to Fig. 4, it will be observed that the cover` I2 is provided with a cam surface 38 which cooperates with a complementary vcam surface @Il formed on the mounting bar 24. Each side ange of the cover l2 is provided with such a cam surface. The cam surfaces 38 and 49 are made parallel to the cam surface 29 on the forward end of the ejecting cam 22 and are directly in line with the cam surface 29 so that any force applied to the cam surface 29 by the empty shell striking the surface 25 is transmitted directly to the cover I2 through the surfaces 38.

As shown in Fig. 4, the cover I2 is cut away at III and 42 so as to provide clearance between the mounting bar 24 and the edges of the cover at these places. 'I'he pressure of the springs 36 against the bar 24 tends to cause the mounting bar 24 to move downwardly by virtue of the inclined cam surfaces 38 and 40 described hereinabove. 'Ihe surfaces 38 and 40 are normally in sliding engagement at all times although there is relative movement between the bar 24 and the cover I2. The spring 36 helps to keep the surfaces 38 and 40 in contact with one another at all times. The arrangement of the springs 3B and the surfaces 38 and 40 is such that the bar 24 is biased downwardly by the springs 36. However, as thev bolt head reciprocates within the receiver housing I the cam 22 together with the mounting bar 24 is free to move upwardly out of the path of the bolt head. 'Ihe lower .position of the ejector has been shown in dot-dash lines in Fig, 4 of the drawing. By virtue of this arrangement, the exact relationship of the cover relative to the path of the bolt is not as critical as in the prior shell ejector design shown in my co-pending application Serial No. 565,252, which has matured into Patent No. 2,411,979 of December 3, 1946. Furthermore, a slightly different form of action takes place in that the cover I2 which limits the movement of the mounting bar 24 is at all times in engagement with the mounting bar 24 through the surfaces 38 and 4U in such a manner that the coverdoes not receive a hammer blow from the mounting bar 24 when the shell strikes the cam surface 26, The studs 25 are providedwith removable heads or stops 44 which hold the mounting bar 24 in assembled relationship relative to the end wall 28. The arrangement described hereinabove serves as a convenient self-compensating means capable of compensating for inaccuracies in the .manufacture of the gun and subsequent wear which tends to alter the clearances between the parts of the gun.

While the form of embodiment of the invention as herein .disclosed .constitutes a preferred form, it is to be understood that other forms might be adopted, as may come within the `scope of the claims which follow.

What is claimed is as follows:

1. In a rapid fire machine gun having a receiver, a receiver cover, shell ejecting mechanism comprising a mounting bar extending transversely of the receiver between the cover and the receiver, a shell engaging cam depending from said bar and arranged so as to engage the upper rear edge of .each empty shell upon extraction of the shell from the gun barrel, and means for adjustably mounting said bar, said bar and said receiver cover having complementary cam surfaces in sliding engagement with one another and arranged at an angle relative to the horizontal axis of the gun, said cam surfaces being so arranged Wherebyrearward movement of said bar will cause downward movement of said bar, and spring means urging said .surfaces into engagement with one another.

2. In a rapid fire machine gun having a receiver housing, a cover for the receiver housing, and a reciprocating bolt mechanism disposed Within said receiver housing; a shell ejecting mechanism .comprising a shell engaging cam and mounting means for yieldably supporting said shell engaging cam between said cover and said receiver housing, said shell engaging cam comprising' a cam element disposed directly above and in sliding engagement with said reciprocating .bolt so as to be moved upwardly by said bolt 4 as said bolt moves past said element and having a forward end for engagement with the chamfer on the rim of the empty shell, said cover and said mounting means having complementary cam surfaces in engagement with one another and slidable relative to one another, said surfaces being arranged so that the shell eje'cting mechanism is cammed forwardly as it moves upwardly.

3. In a rapid fire machine gun, a receiver housing, a cover for said receiver housing, a reciprocating bolt mechanism disposed within said receiver housing, a shell feedway disposed between said cover and said receiver housing, a shell electing mechanism carried by said feed- Way and including a depending member having a cam surface for engaging the upper edge of the empty shells upon extraction of the shells, a portion of said depending member being arranged to project into the path of movement of said reciprocating bolt mechanism so as to be raised by said bolt mechanism, vsaid cover and said shell ejecting mechanism having contacting cam surfaces arranged at an angle to the path of movement of said bolt mechanism, and spring means biasing said contacting cam surfaces into engagement with one another.

4. In a rapid fire machine gun, a receiver housing, a cover for said receiver housing, a reciprocating bolt mechanism disposed within said receiver housing, a shell feedway disposed between said cover and said receiver housing, a shell ejecting mechanism carried by said feedway and including a depending fmember having a cam surface for engaging the upper edge of the empty shells upon extraction of the shells, a portion of said depending member being arranged to project into the lpath of movement of said reciprocating bolt mechanism so as to be raised by said bolt mechanism, said cover and said shell ejecting mechanism having contacting cam surfaces arranged at an angle to the path of movement of said bolt mechanism, and spring means biasing said contacting cam surfaces into engagement with one another, the arrangement 0f said cam sufaces relative to said spring means being such that said spring means biases the shell ejecting mechanism downwardly relative to said cover.

5. Inl a rapid fire machine gun having a receiver, a receiver cover, and a feedway mounted between the receiver and the receiver cover, a shell ejecting mechanism comprising a mounting bar loosely carried by said feedway and extending transversely of the receiver between the cover and the receiver, a shell engaging element depending from said bar and arranged so as to engage the upper rear edge of each empty shell upon extraction of the shell from the gun barrel, spring means interposed between said feedway and said mounting bar biasing said mounting bar towards the rear of the gun, said cover having cam means arranged in engagement with a portion of said mounting bar for camming said mounting bar downwardly as the mounting bar moves to the rear, said cam means, mounting bar, and feedway being so constructed and arranged that rearward movement of said mounting bar causes said downward movement.

6. In a rapid re machine gun, a receiver housing, a barrel, a cover for said receiver housing, a reciprocating bolt mechanism disposed Within said receiver housing, said receiver housing having an ejection opening in the bottom wall thereof, a shell ejecting mechanism comprising a shell electing cam disposed above the path o f movement of said bolt for engagement with the empty shells upon extraction from said barrel and for interrupting backward movement of the upper edge of the shell so as to ilip the shell downwardly through said opening, means for biasing said shell ejecting mechanism rearwardly of the gun, and cam means for camming the shell ejecting mechanism {downwardly as the shell ejecting mechanism moves rearwardly.

7. In a firearm, the combination with a receiver housing; of a shell electing mechanism comprising a mounting bar loosely carried by said receiver housing, a shell ejecting cam element depending from said mounting bar and having a forward inclined surface for engagement with the rim of an empty shell in the process of extraction, means for biasing said mounting bar towards the rear, and cam means for camming said mounting bar downwardly as the mounting bar moves towards the rear', said cam means having a cam surface substantially parallel to said inclined surface.

8. In a firearm, the combination with a stationary receiver housing part; of a shell ejecting mechanism comprising a shell ejecting element, a mounting bar extending transversely of said housing for supporting said element in the path of movement of the edge portion of the empty shells being extracted from the barrel of the gun, means for loosely mounting said bar on said housing part, said last named means being so constructed and arranged that the mounting bar is free to move both vertically and horizontally, and means for guiding the movement of said mounting bar so as to move at an angle relative to the vertical and the horizontal.

' 9. In a rapid re machine gun, a receiver housing, a barrel, a cover for said receiver housing, a reciprocating bolt mechanism disposed Within said receiver housing, said receiver housing having an ejection opening in the bottom wall thereof, a shell ejecting mechanism comprising a shell ejecting cam disposed above the path of movement of said bolt for engagement with the empty shells upon extraction from said barrel and for interrupting backward movement `of the upper edge of the shell so as to ip the shell downwardly through said opening, a mounting bar for said shell ejecting cam arranged transversely of said receiver housing with the ends of the bar projecting on opposite sides of said housing, means for loosely supporting the projecting ends of said bar, said cover having an inclined surface provided thereon, said mounting bar having a complementary inclined surface arranged in sliding contact with said rst named inclined surface, and spring means for biasing said surfaces into mutual engagement, said spring means and said surfaces being so constructed and arranged that said shell ejecting cam is normally biased downwardly into shell ejecting position but is allowed to move upwardly enough so as to allow passage thereunder of said reciprocating bolt mechanism.

10. In a rapid re machine gun, a receiver housing, a reciprocating bolt mechanism disposed within said receiver housing, a shell ejecting mechanism carried by said housing and including a depending member having a cam surface for engaging the upper edge of the empty shells upon extraction of the shells, a portion of said depending member being arranged to project into the path of movement of said reciprocating bolt mechanism so as to be raised by said bolt mechanism, said housing and said shell ejecting mechanism having contacting cam surfaces arranged at an angle to the path of movement of said bolt mechanism, and spring means biasing said contacting cam surfac into en' gagement with one another, the arrangement of said cam surfaces relative to said spring means being such that said spring means bias said shell ejecting mechanism downwardly relative to said housing.

FRANCIS I. RATAICZAK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 580,935 Ehbets Apr. 20, 1897 828,977 Schouboe Aug. 21, 1906 1,041,410 Benet et al, Oct. 15, 1912 1,090,351 Swebilius Mar. 17, 1914 1,786,207 Hudson Dec. 23, 1930 2,101,236 Burton Dec. 7, 1937

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