US2591733A

US2591733A - Extractor for firearms

Info

Publication number: US2591733A
Application number: US59001A
Authority: US
Inventors: Clarence E Simpson
Original assignee: US SEC WAR
Current assignee: United States, WAR, Secretary of; US SEC WAR
Priority date: 1948-11-08
Filing date: 1948-11-08
Publication date: 1952-04-08
Anticipated expiration: 1969-04-08

Description

April 8, 1952 c. E. SIMPSON 2,591,733

EXTRACTOR FOR FIREARMS Filed Nov. 8, 1948 Flg l awuc/wtom Ellurenc: E EJEn'Lm .5011.-

Patented Apr. 8, 1952 EXTRACTOR FOR F IREAR-M S Clarence E. Simpson; Springfield, Mass assignor to-the United States of America as represented by the Secretary of War Application November 8, 1948, S'eriai No. 59,001

2 Claims. (01.42-25') (Granted under the act of March 3, 1883, as amended April 30, 1928; 370' G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon;

This invention relates to an extractor for firearms and to the mounting of such extractor to the" bolt of a firearm.

It is an object of this invention to provide a firearm cartridge extractor having unusual strength and smallness of size for mounting withina limited space on a firearm bolt.

Another object of this invention is to provide a unique extractor mounting means for pivotally securing the extractor to 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. 1 is a fragmentary view of a firearm bolt shown partially in longitudinal section to illustrate the manner of mounting the extractor therein.

Fig. 2 is a right end view of Fig. 1.

Fig. 3 is a perspective view of the extractor.

Fig. 4 is an enlarged fragmentary cross-sectional view showing the extractor in position to ride over the rim of a cartridge case as the bolt moves forwardly.

In Fig. 1 there is shown a firearm bolt l0 having assembled thereto an extractor 20 constructed in accordance with the teachings of this invention. Bolt is comprised of two parts, a forward cylindrical portion I I and a rearwardly integral body portion l2 of substantially rectangular construction. The forward face of bolt [0 is cylindrically recessed as shown at l3 to accept the base of a cartridge (not shown). A longitudinally disposed firing pin hole I4 is provided in bolt l0 and is of suitable configuration to receive a firing pin (not shown) and such hole communicatesaxially with recess l3. On the underside of the cylindrical portion ll of bolt I0 there is provided a longitudinally disposed slot 15. A rectangular recess I6 is provided above and communicating with such slot, as shown in Fig. l, for a purpose that will presently appear. A transverse hole I1 is provided in the cylindrical portion ll of bolt l0 which intersects recess l6 as shown in Fig. 1. Rearwardly of recess I6 there is provided a cylindrical recess IS in which is inserted a spring l9.

Extractor essentially comprises a rectangular body portion 26 and is provided with a cartridge engaging hook 2| on the forward end thereof. The end of hook 21 is arcuately shaped as shown in Fig. 3 to engage the extractor groove of a cartridge (not shown). Somewhat rearwardly of the center of extractor 20 there is provided a lug 22. The top surface of such lug is sloped rearwardly and downwardly as shown at 23' for a purpose to presently appear. The rear face of lug- 22 is provided with an arcuate surface as shown at 29 and such arcuate surface bears against the contiguous face of recess l6 thus providing a relatively frictionless bearing as extractor 20 pivots in a manner to be later explained. An arcuate transverse groove 24 is provided on the forward face of lug 22 which is engageable by a pin as will be later described. Rearwardly of lug 22 there is provided a cylindrical recess 25 in extractor 20.

Slot l5 accommodates bodyportion 26 of extractor 20 and recess l6 accommodates lug 22. The free end of spring I9 projecting. out of recess I8 then enters recess 25 of extractor '20. When extractor 20 is fully seated within longitudinal slot I5 by external pressure against the bias of spring l9, a pin 2-! may then beinserted through hole I! in bolt [0. The semi-cylindrical groove 24' in upstanding lug 22 provided on extractor 29 will then be engaged by pin- 21 thus pivotally securing such extractor within slot IS. The confines of recess l6 substantially eliminate longitudinal displacement of extractor 20 whereby groove 24 is maintained in pivotal contact with pin 21. The bias of spring [9 tends to rotate extractor 20 in a counterclockwise direction about pin 21 whereby hook portion 2| of extractor 20 is rotated into engagement with the extractor groove of a cartridge (not shown). When. the hook portion 2| of extractor 20 is cammed downwardly in striking the base of a cartridge on the feeding stroke of the bolt, the force or blow against the extractor is transmitted to the bolt by the arcuate surface 29 being in contact with the rear wall of recess 16 and therefore such end receives substantially all of the load and pin 21 none. Pin 21 being half supported by the bolt transmits any load applied to it upon extraction of the fired case to the bolt. The sloped upper surface 23 of lug 22 permits limited pivotal movement of extractor 20 about pin 21 in a clockwise direction so that the extractor can be pivoted downwardly out of the cylindrical recess l3 provided in the face of bolt ID as a cartridge strikes a sloped surface 28 provided on the forward face of hook portion 2| whereby the base of such cartridge'may be seated in recess [3.

Extractor 20 having such a short length and being of substantial dimensions, particularly the hook portion thereof, is thus able to withstand the heavy pounding experienced by the rapid reciprocation of bolt l0 within an automatic firearm. Hook portion 2| has to withdraw the fired case from the chamber of the .barrel and obviously such hook must be adequately strong to withstand the tremendous force required to extract the case. The lug construction on the body of the extractor is amply large to permit pivotal mounting and to resist the force required to extract the fired case. Such mounting means permits rapid assembly or disassembly of the extractor to the firearm bolt. The spring bias provided to engage the hook portion of the extractor with the extractor groove provided in the cartridge case is ample to perform such service without over-stressing the spring. By the use of such arrangement the body portion 26 of the extractor can be made exceptionally heavy compared to more conventional types of extractors, inasmuch as the need for relying on the spring action of the body of the extractor to engage the hook portion thereof with the extractor groove of a cartridge is eliminated entirely. Thus there is here provided an extractor of unusual strength and one requiring but a simple and unique mounting for pivotally securing the eX- tractor to a firearm bolt.

I claim:

1. In a firearm, the combination of a reciprocable bolt having a rectangular recess therein, a cartridge case extractor having a rigid body portion terminating in a claw portion at the forward end thereof, a lug projecting from said extractor body portion and being of lesser width than said bolt recess in order to provide a loose fit therebetween when said extractor is assembled to said bolt with said lug entering into said recess, a transverse pin jointl engageable with the front end surface of said lug and the front wall surface of said bolt recess for pivotally retaining said extractor to said bolt, said pin cooperating with said lu for locating the top thereof in spaced relation with the bottom of said bolt recess when said extractor lies in an unpivoted position, the underside of said bolt rearwardly of said recess therein being in a higher plane than the portion forwardly thereof in order to cooperate with the loose fit and the space between said lug and said bolt recess for permitting clockwise pivotal movement of said extractor about said pin upon impact between said claw portion and the rim of a cartridge case during forward movement of said bolt, and resilient means for returning said extractor to the position wherein said claw portion is in gripping engagement with the rim of the cartridge case.

2. In a firearm, the combination of a reciprocable bolt havin a longitudinal rectangular slot in the underside thereof and a vertical rectangular recess communicating with said slot, a

4 cartridge case extractor having a rigid, longitudinally extending body portion terminating at the forward end thereof in a claw portion, a lug projecting upwardly from said body portion and having an arcuate rear end surface contiguous with an upwardly and forwardly sloping top surface, said bolt recess being of greater width than said lug in order to provide a loose fit therebetween when said extractor is assembled to said bolt with said body portion in said slot and said lug in said recess, said bolt having an arcuate groove transversely across the front wall of said rectangular recess, said extractor lug having a similar arcuate groove transversely across the front end surface thereof for alignment with said bolt groove to form a transverse hole through said bolt, a pin disposed in said hole for pivotally retaining said extract-or to said bolt, the vertical location of said groove in said lu bein such that said sloping top surface thereof forms an, angular clearance with the bottom of said recess' in said .bolt when said extractor lies in the unpivoted position thereof, said bolt slot being of greater depth rearwardly of said rectangular recess than forwardly thereof in order to cooperate with said loose fit and said angular clearance between said lug and said bolt recess for ermitting clockwise pivotal movement of said extractor about said pin upon impact between said claw portion and the rim of a cartridge case during forward movement of said bolt, said arcuate rear end surface of said lug contacting the rear end wall of said bolt recess upon impact between said claw portion and the base of the cartridge case whereby the resulting shock is transmitted through said lug to said bolt and away from said transverse pin, and resilient means operative on the rear end of said extractor body portion for pivoting said extractor counter-clockwise about said pin to bring said claw portion into gripping engagement with the rim of the cartridge case.

CLARENCE E. SIMPSON.

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

UNITED STATES PATENTS Number Name Date 1,315,295 Forbes Sept. 9, 1919 1,401,552 Pedersen Dec. 27, 1921 1 1,889,099 Loomis Nov. 29, 1932 2,101,236 Burton Dec. '7, 1937 2,350,477 Rowley June 6, 1944 2,462,889 Neidhardt Mar. 1, 1949 FOREIGN PATENTS Number Country Date 695,924 Germany Sept. 6, 1940