US3906651A

US3906651A - Cartridge case extractor mechanism for firearms having rotary breech closure

Info

Publication number: US3906651A
Application number: US435748A
Authority: US
Inventors: Erkki Vesamaa
Original assignee: Valmet Oy
Current assignee: Valmet Oy
Priority date: 1973-01-26
Filing date: 1974-01-23
Publication date: 1975-09-23
Anticipated expiration: 1992-09-23
Also published as: FI48878B; FI48878C

Abstract

A firearm breech mechanism including a bolt supported for turning and axial movement and having a front end region which terminates in a front end face which is adapted to engage the rear end of a cartridge case. The front end region of the bolt has an outer surface at least part of which determines the maximum radius of the bolt at its front end region. This front end region of the bolt carries an extractor structure for cooperating with a cartridge case to extract the latter during the rotary and axial movement of the bolt. The extractor structure is accommodated by the bolt in such a way that the extractor structure in its entirety does not extend beyond the above maximum radius from the axis of the bolt.

Description

States atet 1191 Vesamaa Sept. 23, 1975 [5 CARTRIDGE CASE EXTRACTOR 3,142,923 8/1964 Vartanian et al. 42/25 MECHANISM FOR FIREARMS HAVING 3,397,473 8/1968 Browning 42/25 3,477,162 11/1969 Morse 42/25 ROTARY BREECH CLOSURE [75] Inventor: Erkki Vesamaa, .Iyvaskyla, Finland [73] Assignee: Valmet 0y, Finland [22] Filed: Jan. 23, 1974 [21] Appl. No.: 435,748

[30] Foreign Application Priority Data Jan. 26, 1973 Finland 230/73 [52] US. Cl. 42/25 [51] Int. Cl? F41C 15/00 [58] Field of Search 42/25 [56] References Cited UNITED STATES PATENTS 804,699 11/1905 Benet et al 42/25 1,005,263 10/1911 McClean 42/25 2,198,610 4/1940 Garand 42/25 2,984,924 5/1961 Reed 1 1 42/25 3,021.634 2/1962 Johnson 42/25 Primary Examiner-Stephen C. Bentley Assistant Examiner-C. T. Jordan Attorney, Agent, or Firm-Steinberg & Blake [57] ABSTRACT A firearm breech mechanism including a bolt supported for turning and axial movement and having a front end region which terminates in a front end face which is adapted to engage the rear end of a cartridge case. The front end region of the bolt has an outer surface at least part of which determines the maximum radius of the bolt at its front end region. This front end region of the bolt carries an extractor structure for cooperating with a cartridge case to extract the latter during the rotary and axial movement of the bolt. The extractor structure is accommodated by the bolt in such a way that the extractor structure in its entirety does not extend beyond the above maximum radius from the axis of the bolt.

7 Claims, 4 Drawing Figures Q\/, I 2 '1 2 i L73 m i a? 1 W 00,, 0Q s 0 f 1 a .J- I

CARTRIDGE CASE EXTRACTOR MECHANISM FOR FIREARMS HAVING ROTARY BREECH CLOSURE BACKGROUND OF THE INVENTION The present invention relates to firearms.

In particular, the present invention relates to breech mechanisms of firearms which have a bolt which is operated by rotary and axial movement.

The present invention is more especially concerned with a cartridge case extractor mechanism for fire-arms of the above type. t

Cartridge case extracting mechanisms for fire-arms are well known, but conventional extractor mechanisms suffer from several drawbacks. Thus a well known extractor mechanism is the Remington extractor. However, this type of extractor requires an exceedingly long space extending longitudinally of the breech, so that it cannot be accommodated only at the region of a locking lug of a rotary bolt of the breech mechanism.

Another type of Well known extractor is the Winchester extractor. When this type of extractor is used in a firearm having a breech mechanism provided with a rotary bolt, it is essential to mill a space to accommodate one or more of these extractors, necessitating omission of highly desirable locking lugs where the extractor or extractors are situated. Moreover, the Winchester extractor has an undesirably short moment arm requiring a strong relatively stiff separate spring in addition to the return spring of the striker pin.

SUMMARY OF THE INVENTION It is accordingly a primary object of the present invention to provide a breech mechanism of the above general type with a cartridge case extracting structure which will avoid the above drawbacks.

Thus, it is one of the more specific objects of the present invention to provide a breech mechanism which has a rotary and axially movable bolt with a cartridge case extractor structure which does not extend beyond the axis of the bolt through a distance greater than the maximum radius of the bolt at its front end region so that the outer surface of the bolt at its front end region can be substantially uninterrupted and can operate in the best possible manner even though the extractor mechanism is provided at the front end region of the bolt.

Thus, it is an object of the present invention to provide for a breech mechanism, which has a rotary and axially movable bolt provided with locking lugs, a cartridge case extractor mechanism which does not neces sitate elimination of any of the locking lugs and which does not interfere with the normal operation 'of the locking lugs.

Furthermore, it is an object of the present invention to provide for a breech mechanism of the above type a cartridge case extractor structure which does not require a special strong spring in addition to the return spring which acts on the striker pin.

In accordance with the invention the breech mechanism of the firearm includes an elongated bolt means which is supported by a support means for linear and turning movement with respect to acentral axis of the bolt means. This bolt means has a front end region ter minating in a front end face which is adapted to be engaged by the rear end of a cartridge case, and the front end region of the bolt means has an outer surface circumferentially surrounding-the axis of the bolt means with at least part of this outer surface determining the maximum radius of the front end region of the bolt means. The extractor means of the invention is carried by the bolt means at its front end region in such a way that the entire extracto'rmeans is situated at a distance which is no greater than the above maximum radius from the central axis of the bolt means. In this way the extractor means of the invention does not interfere withthe operation of the outer surface of the front end region ofthe bolt means, this outer surface continuing in an uninterrupted manner around the axis of the bolt means.

BRIEF DESCRIPTION OF DRAWINGS The invention is illustrated by way of example in the accompanying drawings which form part of this application and in which:

FIG. 1 is a partly sectional and partly schematic view, taken in a plane which contains the central axis of the bolt, and showing a breech mechanism provided with a cartridge case extractor according to the present invention, FIG. 1 showing the structure as it appears when viewed from above;

' FIG. 2 is an end view of the structure of FIG. I as seen from the right of FIG. 1;

FIG. 3 is aside elevation of an extractor element according to the invention; and

FIG. 4 is a partly sectional elevation of the breech mechanism provided with the cartridge case extractor structure of the invention. 1

DESCRIPTION OF PREFERRED EMBODIMENTS The cartridge case extractor means of the invention includes at least one extractor element 1 which is shown by itself in FIG. 3. Thus it will be seen from FIG. 3 that the cartridge case extractor element 1 has substantially the configuration of a bell crank. This member l has'an arm 10 which extends substantially axially and an arm 12 which extends substantially radially with respect to the central axis of the bolt means 14 which is shown in FIG. 1. The extractor member 1 has a pair of opposed parallel flat surfaces interconnected along the front of the radial arm 12 by a rounded front surface region 8 which forms a reaction surface for the element 1 as will be apparent from the description below. The elongated rear surface of the arm 12 is also rounded, and this rear portion of the arm 12 is formed with a notch 7 of curved configuration for a purpose referred to below. The rounded surfaces of the front and rear elongated regions of the arm 12 adjacent the lower end'thereof, as viewed in FIG. 3, may be considered as forming part of a cylinder whose axis is situated midway between the opposed flat surface regions of the arm 12."

The substantially axial arm 10 of the element 1 is formed with a groove or notch 16 to receive a lip at the rear end of the cartridge case as shown in dotted lines at the right of FIG. 1. Although FIG. 1 shows a pair of extractor elements I cooperating with a lip at the rear of the cartridge case, it is to be understood that the front tipof the arm 10 can be of a suitable configuration'to extend into a cannelure of a cartridge case, to cooperate with this latter type of cartridge case.

As is apparent from FIG. 1, the elongated bolt means 14 is formed with an axial bore which accommodates the striker pin 5. This axial bore 18 of the bolt means 14 also accommodates a return spring 4 which is coiled about the striker pin 5 and has a rear end engaging a flange or collar 20 which is fixed to the striker pin 5. To the rear of the flange 20 the striker pin 5 has a por tion extending through a bore which is formed in a pin 9 which extends perpendicularly across the axis of the bolt means 14 and is accommodated in a pair of opposed openings of the wall of the bolt means 14. This pin 9 has a free end portion extending outwardly beyond the bolt means 14 into a camming groove 22 of an elongated sleeve 24 of the breech mechanism. This sleeve 24 forms at least in part a support means which supports the bolt means 14 for longitudinal movement along and turning movement around the central axis of the bolt means 14, the pin 9 and the camming groove 22 cooperating with each other in a known way to bring about the turning movement of the bolt means 14.

The bolt means 14 has, at its right as viewed in FIG. 1, a front end region which terminates in a front end face 26 which is engaged by the rear end of the cartridge case as shown in FIG. 1. The front end region of the bolt means is provided with a plurality of locking lugs 6 which are distributed circumferentially around the axis of the bolt means 14 as is shown most clearly in FIG. 2. The several lugs 6 terminate in outer surfaces which determine the maximum radium of the bolt means 14 at its front end region, and in accordance with the invention the extractor means 1 in its entirety does not extend beyond the axis of the bolt means 14 through a distance greater than this maximum radius, so that there is no interference in the operation of the outer surfaces of the lugs 6 which have outer surfaces which are practically uninterrupted by the extractor means 1, As is well known the breech includes an action surrounding the bolt and formed with axial grooves with which the lugs 6 are respectively aligned when the bolt is retracted, these lugs 6 being turned to a position where they are out of line with these grooves in order to lock the bolt in the firing position. The firearm includes an unillustrated hammer which is operated in a well known manner by the trigger to strike against the rear end of the striker pin 5 so as to urge the latter forwardly in opposition to the force of the return spring 4. The front tip of the strike pin 5 extends through a bore which is formed in the front end region of the bolt means 14 so as to be capable of striking against the cartridge in order to detonate the same. It will be noted that the pin 9 is formed with a bore which accommodates the portion of the striker pin 5 which extends to the rear of the flange 20 thereof.

According to a preferred embodiment of the invention. a pair of opposed lugs 6 are respectively formed with radial bores which receive the radial arms 12 of a pair of extractor elements 1, as shown most clearly in FIG. 1. These radial bores which receive the radial arms 12 communicate with axially extending notches through which the axial arms of the elements 1 extend beyond the front end face 26 of the bolt so as to be capable of cooperating with the cartridge in a manner illustrated in FIG. 1.

In order to maintain the extractor members 1 assembled with the bolt means 14 and at the same time provide pivots for the members 1, the bolt means 14 accommodates a pair of holding pins 2 which are made of a springy material and which have front curved ends received in the curved notches 7 formed at the elongated rear portions of the radial arms 12 of the extractor elements 1. In accordancewith a further feature of the invention the bolt means 14 is formed with inclined bores which respectively receive the holding pins 2 in the manner shown most clearly in FIG. 1. Thus it will be seen that the forward ends of the holding pins 2 are situated at a greater distance from the axis of the bolt means 14 than the rear ends of the pins 2.

In accordance with a further feature of the invention these rear ends of the pins 2 are in engagement with the tapered front surface of a push ring 3 which freely surrounds the striker pin 5 in the bore 18. The front end of the return spring 4 engages a rearwardly directed shoulder of the push ring 3 so as to urge the latter forwardly, and in this way the force of the return spring 4 acts through the elements 2 on the extractor members 1 to retain the latter assembled with the bolt means 14 as well as to provide pivots therefor as pointed out above.

It will be noted that the curvature of the elongated front surfaces 8 of the arms 12 of the extractor elements 1 conforms substantially to the curvature of the inner cylindrical surface defining the radial bores which receive the radial arms of the extractor elements 1, so that in this way an excellent reaction surface is provided by the front surfaces 8 of the arms 12 of the extractor elements 1.

It will thus be seen that with the structure of the invention the objects set forth above have been achieved. Of course, while in the illustrated construction a pair of opposed extractor members 1 are illustrated, it is to be understood that the illustrated construction can be varied while conforming to the present invention, for example by providing only a single extractor element 1 rather than a pair.

What is claimed is:

1. In a breech mechanism of a firearm, elongated bolt means having a front end region terminating in a front end face which is adapted to be engaged by the rear end of a cartridge case, said front end region having an outer surface extending circumferentially around a central axis of said bolt means and at least part of said outer surface determining the maximum radius of said bolt means at said front end region thereof, support means supporting said bolt means for linear movement along and turning movement around said axis, and extractor means carried by said bolt means at said front end region thereof for engaging and extracting a cartridge case during said linear and turning movement of said bolt means, said extractor means being situated in its entirety at a distance from said axis which is no greater than said maximum radius, said extractor means including at least one extractor member having substantially the configuration of a bell crank and including a radial arm which extends substantially perpendicularly with respect to said axis and an axial arm which extends substantially parallel to said axis forwardly beyond said front end face of said bolt means to engage the rear end region of a cartridge case, said bolt means being formed with an opening in which said extractor member is accommodated, said radial arm of said extractor member having a rear region formed with a notch, and a holding pin carried by said bolt means and having a front end extending into said notch for maintaining said extractor member assembled with said bolt means and for defining a pivot for the extractor member, said bolt means being formed with a bore in which said holding pin is situated, said bolt means also being formed with an axial bore, a striker pin situated in said axial bore, a return spring also situated in said axial bore and surrounding said striker pin, and a push ring surrounding said striker pin, situated forwardly of said return spring and engaged thereby to be urged forwardly, said holding pin having a rear end engaged by said push ring so that through the latter the force of said return spring acts on said holding pin to urge said front end thereof into said notch.

2. The combination of claim 1 and wherein said front end of said holding pin and said notch are both of a curved configuration.

3. The combination of claim 1 and wherein said bore which receives said holding pin extends angularly with respect to said axis with said front end of said holding pin being situated at a greater distance from said axis than said rear end of said holding pin.

4. The combination of claim 3 and wherein said push ring has a front tapered surface engaging said rear end of said holding pin.

5. The combination of claim 4 and wherein said holding pin is made of a springy material.

6. The combination of claim 1 and wherein said bolt means has at said front end region thereof a plurality of locking lugs distributed circumferentially around said axis and respectively having outer surfaces which determine said maximum radius, and one of said locking lugs of said bolt means being formed with said opening which accommodates said extractor member.

7. The combination of claim 6 and wherein a pair of said lugs are diametrically opposed and respectively formed with said openings, a pair of said extractor members being accommodated in said openings.