US3137084A

US3137084A - Bolt mechanism including a pair of extractors for a firearm

Info

Publication number: US3137084A
Application number: US222745A
Authority: US
Inventors: Frederick P Reed
Original assignee: Individual
Current assignee: Individual
Priority date: 1962-09-10
Filing date: 1962-09-10
Publication date: 1964-06-16
Anticipated expiration: 1981-06-16

Description

June 16, 1964 F. P. REED 3,1 7,

BOLT MECHANISM INCLUDING A PAIR OF EXTRACTORS FOR A FIREARM Filed Sept. 10, 1962 4 Sheets-Sheet 1 i e i i a i1 5 i i if a H i 4 Q i I INVENTOR.

Frederick P. RE E BY 4 4, Raw; w 01% June 16, 1964 F. P. REED 3,137,084

BOLT MECHANISM INCLUDING A PAIR OF EXTRACTORS FOR A FIREARM Filed Sept. 10, 1962 4 Sheets-Sheet 2 INVENTOR. Frederick 11R Eadx 0. my a-ifiww June 16, 1964 F. P. REED 3,137,084

BOLT MECHANISM INCLUDING A PAIR OF EXTRACTORS FOR A FIREARM Filed Sept. 10, 1962 4 Sheets-Sheet 3 June 16, 1964 F. P. REED 3,137,084

BOLT MECHANISM INCLUDING A PAIR OF EXTRACTORS FOR A FIREARM Filed Sept. 10, 1962 4 Sheets-Sheet 4 INVENTOR Fred airman :FLREEEF United States Patent 3,137,084 B0111 MECHANISM INCLUDING A PAIR OF EXTRACTOR FOR A FIREARM Frederick P. Reed, Lndlow, Mass, assignor to the United States of America as represented by the Secretary of the Army Filed Sept. 10, 1962, Ser. No. 222,745 7 Claims. (Cl. 4225) (Granted under Title 35, US. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to bolt mechanisms for firearms and more particularly to the firing pin cocking, the eX- tractor and the ejector devices carried thereby.

It is one object of this invention to provide for a tirearm, which is expendable, a bolt mechanism which is simple in design and economical to manufacture yet positive in operation.

It is a further object of this invention to provide a bolt assembly in which the firing pin spring also acts as an extractor spring and in which the extractors act as the ejector through the cooperation of the extractors with the bolt buffer, whereby the extractors open up to release the fired case when the bolt contacts the buffer.

It is a further object of this invention to provide such a bolt mechanism wherein the firing pin is cocked by action of the bolt return spring when the bolt is adjacent its recoil position.

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 longitudinally cross-sectioned view of the front end of the firearm receiver and shows the bolt in battery position;

FIG. la is a rearward continuation of FIG. 1;

FIG. 2 is an enlarged view taken along line 2-2 of FIG. 1;

FIG. 3 is an enlarged view taken along line 33 of FIG. 2;

FIG. 4 is an enlarged view taken along line 4-4 of FIG. 1;

FIG. 5 is an enlarged View taken along line 5-5 of FIG. 3;

FIG. 6 is a fragmentary, longitudinally cross-sectioned View of the rear end of the receiver showing the bolt in the recoil position and the fired case in the ejection P FIG. 7 is an enlarged view taken along line 77 of FIG. 6;

- FIG. 8 is a view similar to FIG. 7 but cut in a longitudinal section;

release pin; and

FIG. 11 is a view similar to FIG. but showing the bolt advanced still further towards battery position with the firing pin cocking lever released from cocking lever stop and the firing pin held cocked by the sear.

Shown in the figures is a firearm 12 having a tubular receiver 14 with a barrel 16 mounted in the front end thereof. Cartridges 18 are fed sequentially from a magazine 28 into receiver 14 at a position to be picked up by a reciprocal bolt assembly 22, during counterrecoil travel to a battery position, for chambering and discharge in barrel 16. Fired case 24 of cartridge 18 is ejected out a port 25 formed in the underside of receiver 14, rearwardly of magazine 20, after being carried by bolt assembly 22 to the recoil position thereof in the receiver.

A cylindrical buffer 26 extends forwardly into receiver 14 from the rear end thereof for contact by the rear end of bolt assembly 22 to stop recoil displacement thereof at the recoil position. A coiled return spring 28 is disposed between the rear end of bolt assembly 22 and the rear end of receiver 14 for biasing the bolt assembly to battery position. Buffer 26 extends into spring 28 to provide support therefor when compressed.

Bolt assembly 22 includes a bolt 30 having a stepped bore 32 which extends axially therethrough and forms a rearwardly facing annular shoulder 34. The front end of bore 32 communicates with a recess 36 formed in the front end of bolt 30 to receive the base of case 24. Recess 36 extends upwardly from the underside of bolt 30 to permit downward displacement of the base of case 24 from a position concentric with bore 32, for ejection of the case through ejection port 25, as hereinafter described.

Slidingly mounted in bore 32 is a firing pin 40 having a cylindrical body portion 42 with a striker portion 44 of smaller diameter extending forwardly therefrom. A spring 46 is disposed in bore 32 rearwardly of body portion 42 for biasing firing pin 40 forwardly to a striking position wherein the front end of the body portion is in contact with shoulder 34 and the end of striking portion 44 projects into recess 36. The rear end of spring 46 is supported by a pair of extractors 48 pivotally mounted on bolt 38 as hereinafter described.

Extractors 48 are partially received by a pair of corresponding channels 50 which extend along the length of bolt 30 on opposite sides thereof. Channels 50 each include a mouth portion 52 which extends inwardly for communication with bore 32 at the rear end of bolt 30. Each of the extractors 48 is provided with a lug 54 which is received by the corresponding mouth portion 52 and a pin 55 extends vertically through each of the lugs to provide a fulcrum for the lateral displacement of the respective extractor 48. An arm 58 extends from lug 54 along the length of bolt 30 and in the respective ones of the channels 58 so as to protrude from the periphery of the bolt. An arcuate tail section 56 extends from each of the arms so as tocurve inwardly over the rear end of bore 32 for contact by the rear end of spring 46 and for contact by the front end of buffer 26 when bolt 30 is in recoil position.

A claw 60 i formed at the front end of each of the arms 58 so as to extend inwardly for engagement with extractor groove 62 of case 24, when the base thereof is positioned in recess 36 in alignment with bore 32, to transfer recoil displacement of bolt 38 to the case and to hold the case extended in axial alignment with the bolt during recoil travel thereof to the recoil position.

Each of the claws 66 is provided with an arcuate face 64 (see FIG. 4) having the same radius as extractor groove 62 so as to prevent vertical displacement of case 24 from recess 36 when the claws are pressed thereagainst. Claws 60 are pressed into resilient engagement with extractor groove 62 by the bias of spring 46 against tail sections 56 which pivot the claws inwardly. The. angular relationship of tail sections 56 to arms 58 is slightly more than 90 so that, when the tail sections are in contact with the front end of buffer 26, arms 58 are pivoted outwardly to displace claws 69 from engagement with extractor groove 62.

As has been noted hereinbefore,ithe outer sides of arms 58 protrude from the respective channels 56 along the length thereof. Such protruding portions are slidingly received by cooperating slots 65 formed along the inside of receiver 14 to prevent rotational displacement of the bolt assembly 22 around the longitudinal axis thereof during reciprocation. Slots 65 are formed deep enough to permit sufiicient displacement of claws 60, to clear the base of case 24 when extractors 48 are pivoted outwardly.

Firing pin 40 is retracted relative to bolt 30 for cooking by a cocking lever 66 which is mounted in body portion 42 at a channel 63 that extends forwardly in the body.

cocking lever 66 outwardly from channel 68. The out- 1 ward displacement of cocking lever 66 is limited by contact thereof with a pin 72 which is mounted through body portion 42s'o as to traverse channel 68. When in contact with pin 72, the cocking lever 66 extends outwardly and forwardly from channel 68.

The free end of cocking lever 66 extends through a longitudinally elongated opening 73 in bolt into a longitudinal channel 74 formed inside of receiver 14. A cocking lever stop pin 76 extends transversely acrosschannel 74 and is positioned so as to be slightly forward of the free end of cocking lever 66 when bolt 30 is in contact with buffer 26 at the recoil position. versely across opening 73 adjacent the rear end thereof is a cocking lever release pin 78 which, during forward.

displacement of bolt 30 relative to firing pin 40, makes earnming contact with cocking lever 66 to pivotally displace the cocking lever free of cocking lever stop pin 76. A forwardly facing ledge 80 is formed in body portion 42 for engagement with a sear 82 which is pivotally mounted in bolt 30 for releasably holding firing pin in cocked position and is actuatable by a trigger actuated bar 84in receiver 14. V e

Operation grip extractor groove 62 of fired case 24 through the force of spring 46 applied against tail sections 56 of extractors 48. When bolt assembly 22 reaches recoil position, it is stopped by contact of'bolt 30 with buffer 26. At the same time, tail sections 56 are also contacted by buifer 26 to cause outward pivotal displacement of extractors 48 tofree claws from case 24 which, through the force of gravity, drops through ejector port 25 during reduced velocity of bolt assembly 22. Also, when bolt assembly 22 is adjacent recoil position the free end of cooking lever 66 snaps over in back of cocking lever stop pin 76 (FIG..8). 1 I

Extending transbolt to the recoil position, said extractors being respecposition, and means for transferring the bias of said return 7 spring to said firing pin for actuation thereof tothe cocked dug a return spring disposed between said bolt and the Spring 2%, which was compressed by bolt assembly 22 during recoil travel thereof, reacts against bolt 30 for displacement thereof" in' counterrecoiltravel to battery position. 'However, firing pin 46 is held against displace- 713161112 with bolt 39 by the contact of cocking lever 66 with cooking lever stop pin 76 (FIG. 9) so that thebolt moves forwardly relative to the firing pin, compressing spring 46. When bolt 30 is displaced to where firing pin 40 is in the cocked position relative thereto, cocking lever re- 7 lease pin '78 contacts cocking lever 66 to cam the cocking lever free of cooking lever stop pin 76, whereby'the firing pin iS released into engagement bysear 82 and is held cocked thereby'during continued forward travel of bolt assembly 22 (FIG. 11'). As bolt assembly 22 moves forwardly, a fresh cartridge 18, previously moved into receiver 14 from magazine 20, is picked up with the impact between claws 6i and the cartridge causing the claws to. snap over the base thereof into extractor groove'62.

From the foregoing it is clearly apparent that'there' is provided herein a bolt assembly which isdistinguished for its simplicityof design andeconomy of manufacture and which is positive in its functions.

Although a particular embodiment of the invention has been described in detail herein, it 'is evident that many variations may. be devised'within the spirit and scope thereof and the following claims are intended to include such,

variations.

I claim:' r r 1. In a firearmihaving a receiver, the combination including a bolt mounted in the receiver forreciprocation between a recoil position and a battery'position, a pair of extractors pivotally mounted on opposite sides of said bolt so as to carry a fired cartridge case.rearwardlywithsaid t'ively provided with an arm extending along the length of said bolt and an 'arcu'ate tail section extending across the rear end of said bolt, and means-for actuating said extractor means to release the. firedcartridge case when said bolt is in'the recoil position, said actuating means including a buffer extending forwardlyfrom the rearrend so as to be contacted bysaid bolt when in the recoil position and by said tail section of each of rsaid extractors, said tail section being formed. so that when in contact with said buffer respective ones of said extractors are pivoted outwardly for release of the fired cartridge case.

2. The combination as defined in claim l'whereinasaid arm is arranged to project outwardly'from said bolt, and including channels formed inside of the receiver to'slidingly receive the projecting arm portion of said extractors.

for preventing angular displacement of said bolt around the longitudinal axis thereof during 'reciprocation in the receiver..

3." The combination asdefined in claim 1 and including a firing pin disposed in said bolt for displacement therein between a cooked position and a striking position, and a 4. The combination as defined in claim '3 and including a return spring disposed'between said bolt and'the rear end of the receiver for biasing said bolt to the battery position.

5. The combination as defined in claim S and includrear end of the reoeiver for biasing said bolt to. the battery position, and cocking means operationally disposed between said firing pin and the receiver to provide relative displacement of said bolt and said firing pin whereby said I firing pin is cockedbythe bias of said return springdurf ing initial displacement of said bolt from the recoil position. V a

6. The combination as defined in claim 5* wherein said cocking means includes a cocking lever pivotally mounted on said firing pin for outward and forward extension through an opening in said bolt into a longitudinal channel formed inside the receiver, a cocking lever stop pin mounted in the receiver so as to transverse said channel and so as to be contacted by the free end of said cocking lever when said bolt is adjacent the recoil position for preventing displacement of said firing pin relative to said bolt during initial displacement thereof from the recoil positions, and a cocking lever release pin mounted through said bolt so as to transfer said opening and contact said cocking lever for pivotal displacement free of said cocking lever stop pin when said bolt is displaced respective to said firing pin to Where said firing pin is located in the cocked position relative to said bolt.

7. The combination as defined in claim 6 and including a sear mounted in said bolt for engagement with said firing pin to releasably hold said firing pin in the cooked position relative to said bolt.

References Cited in the file of this patent UNITED STATES PATENTS 490,650 Grant Jan. 31, 1893 1,786,207 Hudson Dec. 30, 1930 2,204,289 Williams June 11, 1940 3,064,382 Hill Nov. 20, 1962

Claims

1. IN A FIREARM HAVING A RECEIVER, THE COMBINATION INCLUDING A BOLT MOUNTED IN THE RECEIVER FOR RECIPROCATION BETWEEN A RECOIL POSITION AND A BATTERY POSITION, A PAIR OF EXTRACTORS PIVOTALLY MOUNTED ON OPPOSITE SIDES OF SAID BOLT SO AS TO CARRY A FIRE CARTRIDGE CASE REARWARDLY WITH SAID BOLT TO THE RECOIL POSITION, SAID EXTRACTORS BEING RESPECTIVELY PROVIDED WITH AN ARM EXTENDING ALONG THE LENGTH OF SAID BOLT AND AN ARCUATE TAIL SECTION EXTENDING ACROSS THE REAR END OF SAID BOLT, AND MEANS FOR ACTUATING SAID EXTRACTOR MEANS TO RELEASE THE FIRED CARTRIDGE CASE WHEN SAID BOLT IS IN THE RECOIL POSITION, SAID ACTUATING MEANS INCLUDING A BUFFER EXTENDING FORWARDLY FROM THE REAR END SO AS TO BE CONTACTED BY SAID BOLT WHEN IN THE RECOIL POSITION AND BY SAID TAIL SECTION OF EACH OF SAID EXTRACTORS, SAID TAIL SECTION BEING FORMED SO THAT WHEN IN CONTACT WITH SAID BUFFER RESPECTIVE ONES OF SAID EXTRACTORS ARE PIVOTED OUTWARDLY FOR RELEASE OF THE FIRED CARTRIDGE CASE.