US20050235543A1

US20050235543A1 - Cartridge ejection mechanisms and methods for operating the same

Info

Publication number: US20050235543A1
Application number: US11/072,765
Authority: US
Inventors: Johannes Murello
Original assignee: Heckler und Koch GmbH
Current assignee: Heckler und Koch GmbH
Priority date: 2002-04-09
Filing date: 2005-03-04
Publication date: 2005-10-27

Abstract

Cartridge ejection mechanisms and methods of operating the same are disclosed. An illustrated example cartridge ejection mechanism includes a bolt head which has a front face to close a cartridge chamber, a first longitudinal cross-piece on a first side and a second longitudinal cross-piece on a second side. The first and second cross-pieces extend from the front face of the bolt head toward the rear of the bolt head. The cartridge ejection mechanism also includes at least two cartridge extractor hooks spring-mounted to the bolt head in opposed, facing relation to jointly extract a cartridge or cartridge case from the cartridge chamber when the bolt head moves rearward. Additionally, the cartridge ejection mechanism is provided with a stationary ejector assigned to one of the cartridge extractor hooks and having two projection disposed adjacent a corresponding one of the cross-pieces of the bolt head such that, when the bolt head moves sufficiently rearward, the cartridge or cartridge case strikes the projections, pivots around the cartridge extractor hook opposite the ejector, and is ejected to the side opposite the ejector.

Description

RELATED APPLICATION

This patent arises from a U.S. patent application which is (a) a continuation of International Patent Application Serial No. PCT/EP2003/009492, filed Aug. 27, 2003, (b) a continuation of International Patent Application Serial No. PCT/EP2003/009483, filed Aug. 27, 2003, and (c) a continuation-in-part of U.S. patent application Ser. No. 10/956,562, filed on Oct. 1, 2004. U.S. patent application Ser. No. 10/956,562 is a continuation of International Patent Application Serial Number PCT/EP03/09490, which was filed on Aug. 27, 2003. International Patent Application Serial No. PCT/EP2003/009492, International Patent Application Serial No. PCT/EP2003/009483, International Patent Application Serial Number PCT/EP03/09490, and U.S. patent application Ser. No. 10/956,562 are all hereby incorporated herein by reference in the entirety.

FIELD OF THE DISCLOSURE

This disclosure relates generally to handheld firearms, and more particularly, to cartridge ejection mechanisms and methods of operating the same.

BACKGROUND

Throughout this patent, position designations such as “above,” “below,” “top” “forward,” “rear,” etc. are referenced to a firearm held in a normal firing position (i.e., pointed away from the shooter in a generally horizontal direction).
As far as can be inferred from the figures of U.S. Pat. No. 3,906,651, the '651 Patent appears to illustrate a cartridge with a round profile. The cartridge is seated on the breech block of a breech that has two opposing extractor hooks. The reason why this ejection arrangement has been chosen cannot be inferred from this publication, nor is it possible to infer from this publication how the ejector should be arranged and constructed. The profile of the two extractor hooks is also unusual and facilitates sliding from the cartridge border. Such sliding must be possible in the case of one of the hooks, if it is not intended to be uncommonly softly cushioned. However, a longitudinal groove in the breech which is located close to one of the hooks and could hold the ejector may be recognized in FIG. 2 of this publication.
The ejection of some shotgun cartridges, (for example, of the 10 or 12 caliber), is often a problem, particularly in the case of very long cartridge cases and in semi-automatic weapons. Because the rapidly opening breech of a semi-automatic weapon carries the extractor hooks with it, cartridges having a round border profile may slip from the extractor hooks during this rapid opening movement.
Doubling the amount of extractor hooks as known from U.S. Pat. No. 3,906,651 could possibly remedy this problem. Further, having double the amount of extractor hooks could be advantageous in the case of extremely large cartridges which have a disproportionately small border (e.g., flare, tear gas or shotgun cartridges of the 4 caliber (26.5 mm), 4 cm shell cartridges, or the like.).
In former times, small arms, particularly in the case of service weapons, were all constructed for right-handed marksman. Left-handers were, thus, trained to use the weapon with their right hand. Today, however, there is an attempt to do justice to the characteristics of the marksman by, for example, equipping weapons for use by left-handers. Particularly in the case of semi-automatic rifles of the Bullpup style wherein the magazine is located behind the butt, equipping the rifle for use by a left-handed marksman requires ensuring that cartridge ejection is directed away from the face of the marksman, since the ejector is typically located at the level of the cheekbone.
In the case of some weapons, (for example, with aircraft machine guns mounted in helicopters), the direction of ejection is not freely adjustable, but must instead be adapted to the mounting conditions as best as possible. Under such circumstances, it may be desirable to cause the cartridge ejection to take place in any direction, except at the reloading mechanism. For example, if a cartridge gripper seated above the weapon is used, then the ejection can take place to the right or to the left, or even below, depending on where a cartridge case container or spent ammunition bag can be mounted.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view of an example breech of a semi-automatic shotgun.
FIG. 2 is a top view of the breech and ejector of FIG. 1.
FIG. 3 is an enlarged view of an example extractor hook.
FIG. 4 is a partial view of an example ejector, seen from the front or the rear.

DETAILED DESCRIPTION

FIGS. 1-4 illustrate an example ejector mechanism for an example breech of an example semi-automatic firearm. The example weapon of FIG. 1 includes a bolt head (1) which can be moved along two guide rods (3). This bolt head (1) includes a breech block (5). An extractor hook (7) is mounted on each side of the bolt head (1).
An example extractor hook (7) is shown enlarged in FIG. 3. The extractor hook (7) may be, for example, stamped out of sheet metal. The illustrated extractor hook (7) has a somewhat T-shaped profile. The end of the middle jamb of the extractor hook (7) defines a bore hole (9). A rear leg (11) of the extractor hook (7) and a front leg (13) of the extractor hook (7) extend in opposite directions from the middle jamb. Each of the rear leg (11) and the front leg (13) is positioned at a right angle to the middle jamb.
The rear leg (11) of the extractor hook (7) includes an angular connecting piece (15) on its free end. This connecting piece (15) engages in a spiral pressure spring (not shown). The front leg (13) of the extractor hook (7) includes a hook (17) on its free end. The hook (17) has a surface (19) turned toward the middle jamb. The surface (19) defines an acute angle, a, with respect to an axis (88) that runs parallel to the middle jamb of the extractor hook (7) and transverse to the breech block (5) (FIG. 2). Each of the extractor hooks (7) can be pivoted about a substantially vertical axis. Each of these pivot axes is defined by a retaining pin (21) which passes through the bore hole (9) of the corresponding extractor hook (7) (see FIGS. 1 and 2).
Each side of the bolt head (1) includes a longitudinal cross-piece (25). A corresponding one of the extractor hooks (7) is mounted on each of these cross-pieces (25). Each longitudinal cross-piece (25) has an upper and a lower edge. The upper and lower edges extend into the breech block (5) (i.e., to the front face of the bolt head (1)).
FIG. 2 is a top view of the breech of FIG. 1. In the example of FIG. 2, the two extractor hooks (7) are seated on opposite sides of a cartridge (23). An ejector (27) is located behind the bolt head (1). When viewed from the front or from the rear as in FIG. 4, the ejector (27) has a U-shaped cross-section. When the bolt head (1) moves towards the back, a corresponding one of the longitudinal cross-pieces (25) runs through the ejector (27). The legs (29) of the ejector (27) engage the upper and lower surfaces of the corresponding longitudinal cross-piece (25) and extend onto the bolt head (1).
The cartridge or cartridge case (23) is held on the bolt head (1) by the extractor hooks (7). Thus, the cartridge or cartridge case (23) is carried along with the bolt head (1) when the bolt head (1) moves rearward. The ejector (27) remains stationary during this movement of the bolt head (1). Consequently, the longitudinal cross-piece (25) moves through the two legs (29) of the ejector (27) as the bolt head (1) moves to the rear. As the breech block (5) passes the ejector (27), the base of the cartridge (23) runs into the ends of the legs (29) of the ejector (27) and is pressed against the extractor hook (7) adjacent the ejector (27). Due to the interaction of the round profile of the cartridge border with the beveled edge (19) (FIG. 3), the extractor hook (7) is pressed back and the ejector (27) imparts a powerful thrust to the adjacent part of the cartridge border, so that the cartridge (23) tilts around the extractor (7) on the side opposite the ejector (27) and is ejected.
Switching the ejector (27) to the opposite side of the breech from that shown in FIG. 2 causes a similar ejection to the right.
The ejector (27) can be inserted into a longitudinal or transverse slot in the case of the weapon. A component of the weapon or a pin may hold the ejector (27) in this position.
As will be appreciated by persons of ordinary skill in the art, the above-described ejector mechanism is suited for use with a small firearm, (e.g., a semi-automatic weapon), which includes a barrel and a breech that moves approximately from the rear end of the barrel to the rear along the axis of the bore (i.e., along the median axis of the barrel) when opening. The example cartridge ejection arrangement described above includes extractor hooks (7) and an ejector (27). The extractor hooks (7) grasp the border or near the border of the cartridge or engage in the peripheral groove of its base. The ejector (27) is seated approximately opposite one of the extractor hooks (7) in relation to the axis of the bore. The ejector (27) is positioned so that the border of the cartridge base runs into it as the bolt head (1) moves rearward. In the illustrated example, the ejector (27) is stationary. Thus, the ejector (27) may be either rigidly mounted to the weapon or its case. Alternatively, the ejector (27) may be flexibly mounted in the breech or the bolt head (1) to, at the end of the return motion of the breech, run into a weapons-proof resistor.
In the illustrated example, the cartridge or cartridge case is ejected transverse to the axis of the bore. The extractor hooks (7) are on opposite sides of the axis of the bore. The ejector (27) is located on the side of the axis of the bore opposite to the side to which the cartridge is to be ejected.
In the case of cartridges with a border groove which is turned toward the breech block (i.e., toward the front surface of the breech (5)), the cartridge border forms an even surface (i.e., is flush) with the front surface of the breech (5). During ejection, the extractor hooks (7) are snugly seated in the grooves with a complementary supporting surface. Therefore, the cartridge or its case cannot be released from the extractor hooks (7) until a transverse force is applied to the case. In this way, a reliable ejection of the cartridge case is ensured. In the case of a cartridge border with a round profile, (for example, in the case of small arm and shotgun cartridges), the engagement between the cartridge case and the extractor hooks (7) is only a frictional connection. A powerful spring is, thus, employed to stress the extractor hooks (7) toward the cartridge case in order to ensure the cartridge case remains captured between the hooks (7) during withdrawal and, thus, to ensure reliable ejection.
From the foregoing, persons of ordinary skill in the art will appreciate that improved cartridge ejection arrangements have been disclosed. Further, the ejection arrangements illustrated above enable the ejection direction to be changed to suit the marksman or situation presented by the intended use of the weapon.
For instance, in the disclosed examples, a stationary ejector (27) is assigned to one or both of the cartridge extractor hooks (7) such that, when the breech or bolt head (1) moves rearward, the cartridge or cartridge case is extracted from the cartridge chamber by all of the cartridge extractor hooks (7). Subsequently, the base of the cartridge strikes the stationary ejector (27), pivots around the cartridge extractor hook (7), and, in the process, is ejected to the side of the firearm opposite the ejector (27).
It is assumed that each of the extractor hooks (7) has only a limited capacity for keeping the cartridge (23) or cartridge case in the position in which it is pulled out. The use of several extractor hooks (7) is beneficial, particularly with problematic cartridges such as those mentioned above. If an ejector (27) may be assigned to any of the extractor hooks (7), except for those on whose side the ejection is to take place, then the ejection can take place in any desired direction.
Persons of ordinary skill in the art will appreciate that the possible number of extractor hooks (7) is limited by practical considerations such as weight and cost. Typically, three or more extractor hooks will only be practical for cartridges with very large diameters. In keeping with these considerations, the examples illustrated above include only two opposed cartridge extractor hooks (7) and one movable ejector (27). This approach is sufficient for Bullpup weapons.
If the ejector (27) includes two ejector projections arranged on opposite sides of one of the two cartridge extractor hooks (7) and which run in longitudinal grooves of the breech or bolt head (1) that are in open communication with the front face of the bolt head (1) on both sides of the cartridge extractor hook (7), then an ejection arrangement is created, which extracts even difficult cartridges and cartridge cases. This arrangement can be converted with the simplest of resources from right to left ejection and vice versa. In particular, to convert the ejection arrangement from right to left ejection or vice versa, only the ejector projections need be moved. The locations of the breech and the extractor hooks (7) remain unchanged.
Conventional cartridge extractor hooks have hooked shaped ends with surfaces turned toward the breech block to engage a cartridge border. Unlike these prior art extractor hooks, the extractor hooks (7) disclosed herein have ends with surfaces that form an acute angle relative to a plane parallel to the front face (5) of the bolt head (1) such that the surfaces are angled out from the breech block (5) toward the front of the weapon. Preferably, this acute angle ranges between 0° and 15°.
In the above mentioned U.S. Pat. No. 3,906,651, the extractor hooks are designed to complement the profile of the cartridge border with which they are to be used. In contrast, in the disclosed example in which the surface of the extractor hooks (7) form acute angles relative to a plane parallel to the front face (5) of the bolt head (1), cartridges of widely varying styles may be used (e.g., a cartridge (23) whose border is parallel to the front surface (5) of the bolt head (1) or a cartridge having a border which is turned away from the front surface (5) of the bolt head (1) (e.g., flare cartridges)) Such cartridge cases are manufactured by turning on a lathe or by indirect extrusion.
Persons of ordinary skill in the art will appreciate that the above disclosed arrangements may be used for all kinds of small arms. It is particularly advantageous to employ these arrangements with large caliber cartridges. For example, it is especially preferred to employ the illustrated arrangements with a repeating or semi-automatic shot gun. In such circumstances, the structural diversity and mutual deviation between cartridges of the same caliber is particularly great. On the other hand, the need for retrofitting a weapon for left-handed and right-handed marksmen is also particularly great. Such a weapon is typically not a personal weapon like an automatic rifle, which can accompany a soldier during practically his entire period of duty, but rather is often only given out for special operations.
Example cartridge extraction and ejection assemblies are described in U.S. patent application Ser. No. ______ (Attorney Docket No. 20020/10047), which has been incorporated herein in its entirety by reference. Example breech mechanisms are disclosed in U.S. patent application Ser. No. ______ (Attorney Docket No. 20020/10047) and in U.S. application Ser. No. ______ (Attorney Docket No. 20020/10055), which is hereby incorporated herein in its entirety by reference.
Although certain example methods, apparatus and articles of manufacture have been described herein, the scope of coverage of this patent covers all methods, apparatus and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.

Claims

1. A cartridge ejection mechanism comprising:

a bolt head having a front face to close a cartridge chamber, a first longitudinal cross-piece on a first side of the bolt head and a second longitudinal cross-piece on a second side of the bolt head, the first and second cross-pieces extending from the front face of the bolt head toward the rear of the bolt head;

at least two cartridge extractor hooks spring-mounted to the bolt head in opposed, facing relation to jointly extract a cartridge or cartridge case from the cartridge chamber when the bolt head moves rearward; and

a stationary ejector assigned to one of the cartridge extractor hooks and having two projection disposed adjacent a corresponding one of the cross-pieces of the bolt head such that, when the bolt head moves sufficiently rearward, the cartridge or cartridge case strikes the projections, pivots around the cartridge extractor hook opposite the ejector, and is ejected to the side opposite the ejector.

2. A cartridge ejection mechanism as defined in claim 1, wherein at least one of the cartridge extractor hooks includes a hook-like end having a surface facing the front face of the bolt head, the surface of the hook-like end being disposed at an acute angle to a plane parallel to the front face of the bolt head.,

3. A cartridge ejection mechanism as defined in claim 2, wherein the acute angle is between approximately 0° and approximately 15°.

4. A cartridge ejection mechanism as defined in claim 1, wherein the cartridge ejection mechanism is structured to extract a cartridge or cartridge case having a caliber of at least 15 mm.

5. A cartridge ejection mechanism comprising:

a bolt head having a front face to close a cartridge chamber, first and second longitudinal grooves on a first side of the bolt head and a third and fourth longitudinal grooves on a second side of the bolt head, the longitudinal grooves extending from the front face of the bolt head toward the rear of the bolt head;

a stationary ejector assigned to one of the cartridge extractor hooks and having two projection disposed in corresponding ones of the grooves of the bolt head such that, when the bolt head moves sufficiently rearward, the cartridge or cartridge case strikes the projections, pivots around the cartridge extractor hook opposite the ejector, and is ejected to the side opposite the ejector.

6. A cartridge ejection mechanism as defined in claim 5, wherein at least one of the cartridge extractor hooks includes a hook-like end having a surface facing the front face of the bolt head, the surface of the hook-like end being disposed at an acute angle to a plane parallel to the front face of the bolt head.,

7. A cartridge ejection mechanism as defined in claim 2, wherein the acute angle is between approximately 0° and approximately 15°.

8. A cartridge ejection mechanism as defined in Claim l, wherein the cartridge ejection mechanism is structured to extract a cartridge or cartridge case having a caliber of at least 15 mm.

9. A method of ejecting a cartridge comprising:

grasping a rear edge of a cartridge or cartridge case with at least two cartridge extractor hooks spring-mounted to a bolt head in opposed, facing relation;

carrying the cartridge or cartridge case rearward with the bolt head; and

striking the cartridge or cartridge case on two projections of a stationary ejector assigned to one of the cartridge extractor hooks to pivot the cartridge or cartridge case around the cartridge extractor hook opposite the ejector and eject the cartridge or cartridge case to the side opposite the ejector.