US3497983A

US3497983A - Cartridge case extractor for automatic firearms

Info

Publication number: US3497983A
Application number: US697337A
Authority: US
Inventors: Tilo Moller
Original assignee: Heckler und Koch GmbH
Current assignee: Heckler und Koch GmbH
Priority date: 1967-01-12
Filing date: 1968-01-12
Publication date: 1970-03-03
Anticipated expiration: 1987-03-03
Also published as: FR1550779A; GB1191392A; DE1578386B1; BE709234A; CH463325A; ES349153A1

Description

CARTRIDGE OASE-lv EXTRACTOR FOR AUTOMATIC FIREARMS Filed Jan. 12 1968 nnmutmli.

MQQKRSQ INVENroR 7"/0 MLLER BY ay/Maa United States Patent 3,497,983 Patented Mar. 3, 1970 ice 3,497,983 CARTRIDGE CASE EXTRACTOR FOR AU'IQMATIC FIREARll/lf Tilo Mller, Brandacker, Germany, asslgnor to Firma Heckler 6r Koch GmbH, Oberndorf, Germany Filed Jan. 12, 1968, Ser. No. 697,337 IClaims priority, application Germany, Jan. 12, 1967, H 61,537 Int. Cl. F41c 15/02 U.S. Cl. 42-25 3 Claims ABSTRACT GF THE DISCLOSURE A breechblock for firearms has a breechblock head provided with an extractor means in the form of a lever which -is disposed in a recess extending parallel to the forward end face of the breechblock and which is pivotal about an axis parallel to the longitudinal axis of the breechblock, one end of the lever being loaded by a spring 1nserted in the breechblock head, and the other end of the lever being provided with a claw `which is directed parallel to the forward end face and is adapted to engage over the rim of a cartridge case bottom supported on an abutment surface which is provided on the forward end face of the breechblock head.

This invention relates to a breechblock for firearms, in particular automatic hand held firearms, having an extractor which displaceably mounted in the breechblock and is pressed by a spring.

Providing an extractor at the breechblock of a firearm is subjected to considerable difficulties, because the extractor has to absorb considerable forces on the one hand, and on the other not much room is available for accommodating the extractor. In the case of arms in which the recoil movement of the breechblock is effected by the gas pressure on the bottom of the cartridge case after ignition of the cartridge, so that the cartridge case is ejected from the cartridge chamber and pushes the breechblock forward, the extractor admittedly has to secure only the position of the cartridge case at the breechblock head. However, the extractor must withstand considerable forces when the cartridge comes into engagement `with the ejector by the recoil movement of the breechblock and is ejected Iby the ejector, wherein the cartridge performs a tilting movement around the extractor claw which is in engagement with the bottom of the cartridge, In order to ibe able to absorb these forces, the extractor must be made very strong and there must be no possibility for displacement from its position by the forces occurring during ejection. On the other hand, however, there is not much room available for accommodating the extractor claw, in particular when locking members are mounted in the breechblock head, for which recesses of considerable magnitude must be provided in the breechblock head. The extractor must then be disposed betwen these locking members and the front face of the breechblock head so that substantially its length determines the distance between the locking members and the forward end face of the breechblock head. This constructional length affects directly the total length of the firearm and in particular also the length of the locking member preceding the cartridge chamber. Therefore the object must be to keep this constructional length as small as possible, so that the constructional length and thus the weight of the firearm can be kept low.

In general, the extractor is constructed as a pawl which is disposed parallel to the longitudinal direction of the breechblock. It is understood that such a pawl requires considerable space, this being an important disadvantage for the reasons explained above. So that the extractor can be kept as short as possible, the extractor' of a known manual firearm is reduced to a relatively small plate which is inserted externally into an appropriate recess in the breechblock 'head and is pressed and held in the recess by a very powerful torsion spring. In order to secure the position of this plate in the longitudinal direction of the breechblock, the edges of the plate are provided with cut-outs which are engaged by projections provided in the recess of the breechblock head. It s understood that the recess as well as the extractor plate itself must be produced with extreme precision in order that, on the one hand, the extractor claw disposed on this plate has the correct distance from the abutment surface for the bottom of the cartridge and, on the other hand, the plate can perform the motions necesary for moving away from the edge of the bottom of a cartridge inserted into the barrel of the arm by the breechblock, and then to engage around it. Furthermore, it is disadvantageous in the known firearm that the spring must be made extremely powerful in order to retain the plate securely in its recess, in particular when the cartridge is being ejected. The use of a powerful spring, however, has the consequence that large forces are necessary for deiiecting the extractor from its rest position and for pushing the claw-over the edge of a cartridge case. These forces, however, are provided with certainty only when the breechblock moves from its rearmost position forward into the closing position at full speed. Therefore, it is impossible to let the breechblock slide slowly into its closing position, when the arm is loaded by hand, because there is then no certainty that the cartridge bottom deflects the extractor and comes to rest on the abutment surface of the breechblock head. lSuch an abut-ment, however, is a condition that, on the one hand, the breechblock is correctly locked and, on the other hand, the cartridge is engaged by the striker pin. On the other hand, the freely advancing breechblock produces a relatively loud noise, whereas in use it is frequently desirable that the arm can be made ready for shooting with the least possible generation of noise.

Finally the known extractor has the further disdvantage that its life is shorter than that of the other parts of the firearm because it fractures prematurely under the effect of the high stresses. Admittedly, exchanging the extractor does not present too great a problem. However, the eX- tractor provides a factor of uncertainty which can lead t0 a failure of the firearm just when it is most urgently needed.

A further disadvantage of the known extractors consists in that they have a tendency to yield upwardly under high tensional stresses and to slide off the edge of the cartridge bottom. Such tensional stresses occur always when a case in the cartridge holder and during loading of the arm by hand must be withdrawn from the cartridge holder by means of the extractor. When the extractor slides off the edge of the cartridge bottom and the cartridge case remains in the cartridge holder, a lengthy interruption of the readiness of the firearm for shooting is caused, because the cartridge case must first be laboriously pushed out of the barrel.

The invention is based on the problem to avoid these disadvantages of the known extractors and to provide a breechblock in which the extractor is disposed so that it requires only little space in the longitudinal direction of the firearm so that the breechblock can be made extremely short, is easy to produce and easy to assemble, can be easily deflected by the bottom of a cartridge applied thereto and finally is characterised by a long life, so that premature failure of the arm owing to malfunctioning of the extractor is no longer possible.

This problem is solved according to the invention, in that the extractor is constituted by a lever which extends parallel to the forward end face of the ybreechblock head and is pivotal about an axis directed parallel to the longitudinal axis of the breechblock, the lever being inserted into an appropriate recess of the breechblock head, one end of the lever being provided with a claw directed radially to the end face of the breechblock head, and the other end being loaded by a spring.

It will be clear that according to the invention a tilting lever of considerable length can be used without appreciable space being required in the longitudinal direction of the breechblock head. On the contrary, the lever can be made relatively thin, so that the space required by the extractor in the longitudinal direction of the breechblock head is reduced to a minimum. It is of particular advantage that during a pivotal movement a claw disposed at the one end of the lever is moved parallel to the end face of the breechblock head so that therefore the distance between the inner or rearward surface of the claw and the abutment surface for the cartridge bottom does not change during the pivotal movement of the extractor. Therefore, the tolerance limits to be observed for the spacing of the claw from the abutment surface for the cartridge bottom can also be maintained without great difliculties. Moreover, forces in the longitudinal direction of the breechblock do not effect a pivotal movement of the lever so that these forces need not be absorbed any more by the spring loading the extractor, but are transmitted by the extractor to the walls of the recess which is provided in the breechblock head for housing the extractor. Consequently, the spring need not absorb the forces which are produced during ejection of the empty cartridge case and the spring can be made so weak that without difficulty a cartridge can be moved by hand axially into engagement with the abutment surface of the breechblock, thereby deflecting the extractor. Therefore, when the extractor according to the invention is used the breechblock can be allowed to slide forwardly slowly and without substantial generation of noise when the arm is loaded by hand.

In a preferred embodiment of the invention, the claw is constituted by a lateral projection of the lever which engages over the abutment surface for the cartridge bottom provided at the breechblock head. In this case, the abutment surface for the cartridge bottom can be formed by the bottom of a recess provided at the end face of the breechblock head and the recess for the extractor cam be formed by a groove which is directed transversely to the breechblock head and which is disposed directly behind and outside the abutment surface for the cartridge bottom, and which is continued at one end by a section of the recess which extends to the end face of the breechblock head, this section also being in communication with the recess for the cartridge bottom and receiving the claw of the extractor lever. These grooves can be easily produced and ensure a perfect mounting of the extractor lever without the latter having a disturbing effect of any kind. This is particularly true when the outer surface of the extractor lever is adjusted to the cross-sectional shape of the breechblock head.

The extractor lever can be pressed in a simple manner by a compression coil spring which is inserted into a bore of the breechblock head and which is supported on the inner surface of the lever. The pivot axis for the extractor lever can be constituted by a pin inserted into a bore which terminates in the end face of the breechblock head which is preferably formed by an oblique blind bore. The pin in this case is made so long that it projects into this recess. In this manner, the pin can be inserted from the front and can be pushed out of its bore again by the insertion of a suitable tool into the blind bore. This mounting permits the extractor lever to be assembled and dismantled in a simple manner.

The outer surface of the claw lies preferably in the same plane as the end face of the breechblock head and is bevelled or rounded at its lower edge in order that it is deflected outwardly whe nit meets the cartridge bottom.

Further details and modifications of the invention will be clear from the following description, in which one ernbodiment of the invention is described and explained in detail with reference to the accompanying drawings, In embodiments, the features of the invention may be provided singly by themselves or a plurality thereof, in any combination. ln the drawings:

FIG. l illustrates a perspective view of a breechblock head having an extractor constructed according to the invention,

FIG. 2 is a section through the forward part of the breechblock head of FIG. l along the line ll-II, on an enlarged scale, and

FIG. 3 is a section through the same breechblock head along the line Ill-Ill, the extractor, however, not being in section.

In the drawings a breechblock head 1 consists of a metal block, for example a steel block, which is provided in the region of its forward end face 2 with a circular recess 3, the bottom 4 of which constitutes an abutment surface for the bottom of a cartridge case, the rear end of which ts into the recess. In the center of the abutment surface 4 there is provided a bore 5 for a striker pin (not illustrated in detail) which penetrates axially through the breechblock head 1 in a known manner. Furthermore, the breechblock head 1 is provided with an axial bore 6 which serves for receiving a control member which, however, is not illustrated but by which the locking rollers 8 indicated in FIG. 1 can be pressed outwardly. In thus far, the construction of the breechblock head is conventional so that it need not be described in more detail.

The breechblock illustrated in the drawings is provided with an extractor 11 which is inserted into a groove 12 extending transversely to the longitudinal direction of the block 1. This groove is located directly behind the abutment surface 1tfor a cartridge bottom and radially outside the recess 3 serving for receiving the rear end of a cartridge case, as clearly indicated in FIGS. 2 and 3. The groove 12. is followed by a section 13 of the recess serving for receiving the extractor 11, the recess extending, as clearly visible in FIG. l, to the forward end face 2 of the breechblock head and also being open to wards the recess 3, In this section 13 of the recess, there is located a lateral projection 14 of the ejector level, which forms the claw of the extractor. This claw is directed approximately radially to the recess 3. The outer or forward surface of the lateral projection 14 lies approximately in the same plane as the end face 2 of the breechblock head. Furthermore, the outer or forward surface of this projection is rounded inwardly. The inner surface 15 of the claw 14 extends parallel to the bottom 4 of the recess 3 and is disposed at a distance from the abutment surface 4 such that it extends with a small clearance over the rim provided at the end of a cartridge case.

The lever 11 forming the extractor 11 is mounted approximately in its center on a pin 16 which is inserted into a bore extending in the axial direction of the block 1. This bore terminates at the one end in the end face 2 of the breechblock head and at the other end in an oblique blind bore 17. The pin is made so long that one end thereof projects into the blind bore 17 when its other end is flush with the end face 2 of the breechblock head.

The end of the lever 11 remote from the claw 14 is loaded by a compression coil spring 18 which is inserted into an appropriate opening of the breechblock head 1 and one end of which is supported at the closed end of this opening, the other end resting against the inner surface of the lever 11. The force of the spring 18 is dimensioned so that the extractor lever 11 can be pivoted or deiiected relatively easily and the rear end of a cartridge case can be inserted into the recess 3 of the breechblock by hand and exactly in the axial direction without difiiculty, the extractor being deflected thereby. The deflection of the extractor is effected by the pressure of the rim of the cartridge bottom on the rounded section of the outer surface of the projection 14.

It may be seen that the extractor 11 according to the invention requires only little space in the longitudinal direction of the breechblock head so that the locking rollers can be pushed much closer to the end face 2 of the breechblock head than was possible heretofore. FIG. 1 gives an approximate indication of the space which is saved by using the invention, relatively to the known arrangements. The shortening of the breechblock head makes possible a corresponding shortening of the locking member with which the breechblock head cooperates. Consequently the weight of a iirearm which is provided with the breechblock head according to the invention can be reduced considerably. Furthermore it is clear that the extractor according to the invention can be produced and mounted in a simple manner and also that the recesses required for the extractor can be provided relatively simply, It is of particular advantage that because of the perfect positioning of the lever 11 the distance between the inner surface 1S of the claw 14 and the abutment surface 4 for the cartridge bottom is exactly defined and therefore the required tolerance limits can be easily maintained. Furthermore, forces exerted on the claw 14 in the axial direction do not affect pivotal movement of the lever 11 so that the spring 18 can be made relatively weak so that the extractor is easily deflectable under the effect of radial forces acting upon the rounding of the claw. Moreover the extractor can be made strong enough to resist all forces exerted thereon and has a life which exceeds the life of the whole firearm.

It is understood that the invention is not limited to the embodiment illustrated by way of example, but that modifications thereof are possible. The external contour of the extractor lever 11 will depend upon the shape of the cross-section of the breechblock, because the contour must be adjusted to the cross-sectional shape in order that the extractor does not project in a disturbing manner beyond the outer surfaces of the breechblock. Furthermore the extractor can be used also with breechblocks which have an abutment plate without recess for a cartridge bottom. The extractor according to the invention can be used for breechblocks of all kinds. It is suitable for breechblocks of repeater arms as well as for breechblocks of automatic arms and can be used with advantage for automatic arms having purely mass produced breechblocks or also semi-rigidly or rigidly locked breechblocks.

What I claim is:

1. A breechblock for iirearms, particularly automatic hand firearms, comprising a breechblock head with an extractor in the form of a spring-loaded lever extending parallel to the front face of said breechblock head and pivotable about an axis parallel to the longitudinal axis of said breechblock head, said extractor being countersunk into a corresponding recess in said breechblock head and being provided with a claw at one end which is directed radially with respect to the front face of said breechblock head, wherein the improvement essentially comprises said recess being formed by a groove provided in the circumferential surface of said breechblock head parallel with respect to the front face thereof, said groove being in communication at one end with a recess provided in the front face of said breechblock head against which a cartridge case bottom abuts by means of a radial slot extending up to the front face of said breechblock head, said claw being for-med by a lateral projection of said extractor lever engaging into said radial slot, and the pivot axis for said extractor lever being formed by a pin inserted in a bore which terminates in the front face of said breechblock head.

2. A breechblock for firearms according to claim 1, wherein the outer surface of said extractor lever is shaped to conform to the cross-sectional shape of said breechblock head.

3. A breechblock for firearms according to claim 1, wherein the other end of said bore terminates in a recess of said breechblock head formed by an oblique blind opening into which said pin projects.

References Cited UNITED STATES PATENTS 2,870,562 l/l959 Kimball 42-25 BENJAMIN A. BORCHELT, Primary Examiner S. C. BENTLEY, Assistant Examiner