U.S. patent number 3,906,651 [Application Number 05/435,748] was granted by the patent office on 1975-09-23 for cartridge case extractor mechanism for firearms having rotary breech closure.
This patent grant is currently assigned to Valmet Oy. Invention is credited to Erkki Vesamaa.
United States Patent |
3,906,651 |
Vesamaa |
September 23, 1975 |
Cartridge case extractor mechanism for firearms having rotary
breech closure
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.
Inventors: |
Vesamaa; Erkki (Jyvaskyla,
SF) |
Assignee: |
Valmet Oy (SF)
|
Family
ID: |
8503818 |
Appl.
No.: |
05/435,748 |
Filed: |
January 23, 1974 |
Foreign Application Priority Data
Current U.S.
Class: |
42/25 |
Current CPC
Class: |
F41A
15/14 (20130101) |
Current International
Class: |
F41A
15/14 (20060101); F41A 15/00 (20060101); F41C
015/00 () |
Field of
Search: |
;42/25 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Bentley; Stephen C.
Assistant Examiner: Jordan; C. T.
Attorney, Agent or Firm: Steinberg & Blake
Claims
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.
Description
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.
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 necessitate 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 a
central axis of the bolt means. This bolt means has a front end
region terminating 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 extractor means 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 with the operation of the outer surface of the
front end region of the 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. 1 as seen from the
right of FIG. 1;
FIG. 3 is a side 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.
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 1 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 1 cooperating
with a lip at the rear of the cartridge case, it is to be
understood that the front tip of 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 portion 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 10 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
accordance with 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.
* * * * *