U.S. patent number 3,835,566 [Application Number 05/354,774] was granted by the patent office on 1974-09-17 for cylinder breech mechanism for small arms.
This patent grant is currently assigned to J. P. Sauer & Sohn GmbH. Invention is credited to Heinz Bielfeldt, deceased, Karsten Bielfeldt, Christiane Diehl.
United States Patent |
3,835,566 |
Bielfeldt, deceased , et
al. |
September 17, 1974 |
CYLINDER BREECH MECHANISM FOR SMALL ARMS
Abstract
A firearm includes a receiver, a barrel, a bolt slidable in the
receiver, spreaders mounted in the bolt for being pivoted into a
locking recess on the receiver and a locking element for shifting
the spreaders. The locking element includes rotatable spreader cams
to extend the spreaders in response to rotation of the locking
element in one direction, and includes unlocking cams operable to
engage and shift the spreaders to a retracted position in response
to rotation of the locking element in the opposite direction. A
latch is provided to prevent the locking element from rotating
relative to the bolt when the bolt is withdrawn from the
receiver.
Inventors: |
Bielfeldt, deceased; Heinz
(LATE OF Eckernforde, DT), Diehl; Christiane (Kiel,
DT), Bielfeldt; Karsten (Eckernforde, DT) |
Assignee: |
J. P. Sauer & Sohn GmbH
(Eckernforde, DT)
|
Family
ID: |
5847097 |
Appl.
No.: |
05/354,774 |
Filed: |
April 26, 1973 |
Foreign Application Priority Data
Current U.S.
Class: |
42/16;
89/190 |
Current CPC
Class: |
F41A
3/42 (20130101) |
Current International
Class: |
F41A
3/00 (20060101); F41A 3/42 (20060101); F41c
011/06 (); F41d 003/00 () |
Field of
Search: |
;42/16 ;89/190 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Borchelt; Benjamin A.
Assistant Examiner: Jordan; C. T.
Attorney, Agent or Firm: Burns, Doane, Swecker &
Mathis
Claims
What is claimed is:
1. In a firearm having a receiver, recess means carried by said
receiver, bolt means slidably mounted in said receiver, a firing
pin extending through a bore in said bolt means, at least one
spreader pivotally mounted at one end to said bolt means and
extending generally longitudinally of said bolt means, said
spreader being pivotal radially from an inward, withdrawn position
to an outer locking position within said recess means, and means
for shifting said spreader comprising:
a locking element operably connected to said bolt means;
handle means operably connected to said locking element and movable
within a slot carried by said receiver to afford rotation of said
locking element relative to said bolt means;
said locking element including rotatable neck means projecting into
the bore of said bolt means and being enveloped by and rotatable
relative thereto;
said rotatable neck means carrying at least one spreading cam and
at least one indented section adjacent said spreading cam;
said spreading cam and indented section being arranged such that,
in a closed position of said bolt means, rotation of said neck
means to a locking posture causes said spreading cam to extend said
spreader into said recess means and support said spreader therein,
and rotation of said neck means to an unlocking posture affords
reception of said spreader within said indented section.
2. In a firearm according to claim 1 wherein said spreader is
pivotally connected to and retained by said bolt means by a pivot
pin.
3. In a firearm according to claim 1 wherein said spreader, at the
other end thereof, includes a projection; said locking element
including a control surface engageable with said projection to
retract said spreader from said recess means.
4. In a firearm according to claim 3 wherein said locking element
includes a control disk; an inside cam surface of said control disk
constituting said control surface and over-reaching said projection
in a closed position of said bolt means; said inside cam surface
including at least one unlocking cam disposed in circumferentially
offset relation to said spreader cam.
5. In a firearm according to claim 4 wherein said neck means
carries three evenly spaced spreading cams and three evenly spaced
indented sections, and said inside cam surface carries three evenly
spaced unlocking cams.
6. A firearm according to claim 1 wherein said bolt means is
connected to said locking element for axial shifting movement
therewith.
7. A firearm according to claim 3 wherein said bolt means is
connected to said locking element for axial shifting movement
therewith.
8. A firearm according to claim 1 and further including a latch
pivotally carried by a pivot pin in a recess of said bolt means;
said neck means carrying a slot; spring means for pivoting said
latch into said slot, with said bolt means in an open position, to
lock said bolt means and said locking element against relative
rotation; said latch being disposed out of said slot in a closed
position of said bolt, through the action of said receiver acting
thereon, to accomodate relative rotation between said locking
element and said bolt means.
9. A firearm according to claim 3 and further including a latch
pivotally carried by a pivot pin in a recess of said bolt means;
said neck means carrying a slot; spring means for pivoting said
latch into said slot with said bolt means in an open position to
lock said bolt means and said locking element against relative
rotation; said latch being disposed out of said slot in a closed
position of said bolt through the action of said receiver acting
thereon, to accomodate relative rotation between said locking
element and said bolt means.
10. A firearm comprising:
receiver means including locking recess means;
barrel means secured to said receiver means;
bolt means slidably mounted in said receiver means;
at least one spreader tang carried by said bolt means and arranged
for shifting movement between:
a locking position wherein a portion of said spreader tang is
disposed in said recess means to lock said bolt means against axial
movement, and
a non-locking position wherein said spreader tang is free of said
locking recess means; and
tang-operating means rotatable relative to said bolt means and
being arranged to shift said bolt means axially;
said tang-operating means including means for shifting said
spreader tang into said locking position in response to rotation of
said tang-operating means in one direction.
11. A firearm according to claim 10 wherein said means for shifting
comprises a rotary cam surface carried by said tang-operating
means.
12. A firearm according to claim 10 and further including means for
engaging and moving said spreader tang from said locking position
to said unlocking position in response to rotation of said
tang-operating means in the opposite direction.
13. A firearm according to claim 12 wherein said means for engaging
and moving comprises an auxiliary rotary cam surface carried by
said tang-operating means.
14. A firearm comprising:
receiver means including locking recess means;
barrel means secured to said receiver means;
bolt means slidably mounted in said receiver means;
at least one spreader tang carried by said bolt means and arranged
for shifting movement between;
a locking position wherein a portion of said spreader tang is
disposed in said recess means to lock said bolt means against axial
movement in said receiver means, and
a non-locking position wherein said spreader tang is free of said
locking recess means; and
tang operating means mounted for rotation relative to said tang and
including:
first cam surface means for engaging and shifting said spreader
tang into said locking position in response to rotation of said
tang operating means relative to said tang in a first direction;
and
second cam surface means for engaging and shifting said spreader
tang into said non-locking position in response to rotation of said
tang operating means relative to said tang in a second direction
opposed to said first direction.
Description
BACKGROUND AND OBJECTS OF THE INVENTION
The invention relates to a cylinder breech block mechanism for
small arms. Of particular concern is a breech casing or receiver
portion in which a locking element is movable by means of a bolt
handle which is guided in a slot of the receiver. The locking
element locks the body of the bolt by means of at least one
spreader which is pivotal radially from a withdrawn to a locking,
spreading position and which extends essentially in the
longitudinal direction of the bolt. The spreader is supported by
the bolt and is rotatable into an indentation in the receiver.
One form of such breech mechanism is disclosed in U.S. Pat. No.
2,601,808 and utilizes an axial shifting of the ramp surfaces of a
locking element relative to the body of the bolt to spread the
spreaders in order to lock the bolt relative to the receiver. The
spreaders, whenever they are underrun by the ramp surfaces, are
swung into supporting indentations in the inside wall of the
receiver by the suitable ramp surfaces on the locking element.
Engagement between the surfaces of the indentations and
corresponding countersurfaces of the spreaders serves to transfer
the recoil from the bolt to the receiver. For the purpose of
spreading the spreaders an axial relative shifting of the locking
element and the bolt is therefore necessary, which shifting
requires a certain additional overall bolt length. Moreover, the
swinging of the spreaders into their ineffective or non-locking
position is accomplished by means of the power of a spring or by a
special corresponding slope of the engaging supporting surfaces of
the indentations and spreaders, whereby the former means has the
disadvantage that the reliability of operation may suffer by
fatigue of the spring, and the latter means results in a less
reliable transfer of the force of the recoil to the receiver.
A general object of this invention is to obviate or minimize the
problems discussed above.
A particular object of the invention is to provide a breech
mechanism which may be locked independently of axial movement of
the bolt.
A further object of the invention is to improve the operation of
the spreaders of a breech mechanism in a way which minimizes the
overall length of bolt required.
A further object of the invention is to provide means for
retracting the spreaders independently of the indentation surfaces
and special spring devices. According to this objective, the
in-and-out swinging of the spreaders is to be free of any
accidental causes, i.e., it is to be precisely controlled. Any
possible disturbances of operation as a result of poor gliding on
slanted surfaces of the locking recess or fatigue of return
springs, or similar things, are to be eliminated.
BRIEF DESCRIPTION OF THE INVENTION
The achievement of these objects is accomplished through the
provision of a locking element which is operably connected to the
bolt. The locking element includes means for spreading the
spreaders in response to rotation of the locking element. The
locking element also includes means for positively engaging and
retracting the spreaders.
The locking element includes a neck piece projecting into the bore
of the bolt penetrated by the firing pin. The neck piece is
surrounded by the bolt and is rotatable relative thereto. The neck
piece includes spreader cams operable to push a plurality of
spreaders into the spreading position and support the spreaders in
such position, in response to shifting of the bolt handle to its
locking swivel position. The spreading cams are defined by a
surface of the neck piece, the latter including idented sections on
its periphery between the spreader cams for reception of the
spreaders swung into the ineffective position.
The neck piece also carries unlocking cams which are
circumferentially offset relative to the spreader cams and which
are operable to engage and shift the spreaders to a withdrawn
position.
THE DRAWING
The invention is explained even more exactly with additional
advantageous developments and in connection with the drawing on the
basis of an embodiment given by way of example.
FIG. 1 shows a perpendicular longitudinal section through a breech
mechanism of the invention in its closed or locked state;
FIG. 2 shows the same perpendicular longitudinal cut, in which the
spreader locking is de-activated in response to the bolt handle
being shifted by about 65.degree. as compared to FIG. 1;
FIG. 3 shows a cross section along line 3--3 in FIG. 2;
FIG. 4 shows a section in perpendicular longitudinal section
through the bolt and the locking element while the bolt is pulled
out of the receiver; and
FIG. 5 shows a cross section taken along the line 5--5 in FIG.
2.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
In the figures, the breech casing or receiver is given the
reference number 11, the bolt is 12, the locking element is 13 and
the bolt handle is designated by 14. The locking element is
rotatable around the axis of the barrel by handling of the attached
bolt handle 14. Moreover, the locking element 13 is longitudinally
slidable in the receiver 11 together with the bolt 12. The
customary inside bore, which is constant in its diameter, goes
through the receiver. The rear end of the bolt 12 is provided with
indentations or recesses for the reception and mounting of tangs or
spreaders 15, the spreaders being pivotally mounted on the bolt by
means of hinge pegs 16. The pegs 16 are disposed perpendicularly on
cross-sectional diametric planes and are arranged at the swivel
center of the pivot spreaders 15, whereby, the transfer of force of
the spreaders does not take place by way of the pegs 16, but by
means of the mutually engageable bearing surfaces of the locking
recess and the spreaders. As will be subsequently explained, the
spreaders 15 are operated by the locking element 13.
The front end of the locking element comprises a long neck piece 17
having a smaller diameter and is disposed in a longitudinal bore of
the bolt which is dimensioned correspondingly and through which the
firing pin 18 passes. The neck 17 of the locking element and bolt
12 are fixed relative to one another axially by means of a suitable
bayonet-type catch so as to accomodate relative rotation
therebetween. The bayonet catch, illustrated in FIG. 5, comprises a
cam extension 31 of the neck 17 which projects outwardly beyond the
periphery of the neck. This cam extension 31 is rotatable within a
groove 30 carried by the bolt 12. This groove is positioned and
dimensioned such that the locking element 13 can be pivoted
relative to the bolt 12, within its normal pivot region limited by
the receiver 11, without the occurrence of relative axial
displacement between the bolt 12 and the locking element 13. A
longitudinally, or axially, extending groove 30a is provided in the
inner wall surface of the bolt 12. This groove 30a is angularly
displaced by an amount sufficient to insure that during normal use
of the cylinder breech mechanism the cam 31 will not be able to
enter this axial groove 30a. The axial groove 30a allows relative
assembling and disassembling of the bolt 12 and the locking element
13. The groove 30a is arranged in relation to the normal pivot
region of the bolt 12 such that the bolt 12 and the locking element
13 must be withdrawn from the receiver 11 in order to allow the cam
31 to be displaced angularly more than during its normal pivoting
to bring the cam 31 into axial alignment with the axial groove
30a.
In the rear part of the neck of the locking body, which in the case
of an assembled breech mechanism is located radially inside the
spreaders 15, are provided spreader cams 19 (FIGS. 1 and 3). The
spreader cams 19 correspond in number to spreaders 15 and
correspond to their distribution or positioning on the periphery.
In the case of the embodiment shown by way of example there are
three evenly spaced spreader cams with three evenly spaced
spreaders, the spacing between the spreaders being the same as the
spacing between the cams. Between the cams 19 are disposed indented
grooves or sections 19a with transitional gliding surfaces 19b
located between and interconnecting the indented sections and the
spreader cams.
In the area of spreaders 15, and especially in the area of their
ends, an annular groove or recess 20 has been cut into the cylinder
wall of the receiver 11. The annular groove includes an acute
conical front part 20a, which permits the spreading of spreaders 15
within the receiver bore. An essentially more truncated conical
rear section 20b of the annular groove serves as the supporting
surface for the terminal surfaces of spreaders 15 whenever the
latter are spread.
FIG. 3 clearly shows the arrangement of the spreader cams in the
case of three spreaders 15 distributed evenly on the periphery. In
FIG. 3, furthermore, it can be recognized that a control disk 21 in
top view, which, as can be recognized from the longitudinal section
of FIGS. 1 and 2, has a crank-like recess 21a on its side facing
the spreaders and which is connected to the locking element with
torsional strength and moreover is fixed axially therewith. In
other words, the control disk 21 is arranged to rotate with and be
axially shifted with the locking element. Rear projections 15a of
the spreader extend into the recess 21a of control disk 21, whereby
a mutual, circumferentially offset or staggered arrangement of
control disk 21 relative to the spreader cams of the neck 17 of the
locking element is such that projections 15a will enter into the
recess areas 21a and will be projected further radially outwards
within these recesses whenever the spreaders are spread by the
spreader cams 19. In the case of twisting the locking element by
about 65.degree. by means of bolt handle 14, the spreaders are
forcefully swung out of lock groove 20 of the bolt as a result of
their guidance on the marginal surface 21c of recess 21a and with
the aid of cam-like control projections 21b of the control disk
pointing inwardly, and are swung radially inwards toward the neck
of the locking element body.
In the rear area of receiver 11 there is a bolt catch lever 22
mounted pivotally on a cross pin 23 and coupled with the triggering
device (not shown) in conventional fashion. The upper part 22a of
the bolt catch lever extends into a longitudinal groove 28 of body
12 of the bolt and, as a result, the bolt can move only axially
relative to the receiver but it cannot rotate relative thereto with
the catch lever in the position shown in FIG. 2.
In the front section of neck 17 of the locking body there is a
longitudinal groove 24 (see FIG. 4) on a place of the periphery.
The groove faces a catch 26 pivotal about an axis comprising a
hinge pin 25. The catch stands perpendicularly relative to a
diametric plane through the bolt, in the case of the relative
position of the locking element and the bolt where the spreaders
are swiveled inwardly. This latch is spring loaded at one end by
means of a compression spring 27 so that its rear end, whenever the
bolt is pulled axially from the receiver 11, can swing outwardly
(FIG. 4). In this manner, the front end of the latch swings
inwardly into groove 24, as a result of which, relative rotation
between the locking element 13 and the bolt 12 will be prevented in
the open state of the breech. As a result the spreaders 15, which
are under forced, retracted control as a result of the rotation of
bolt handle 14 and disk 21, will be prevented from spreading while
the breech is opened. Spreading at this time could lead to a
functional disturbance in the breech in the case of a renewed
closing of the bolt.
OPERATION
In FIG. 1, the completely closed locked breech is shown. It is
desirable, however, to explain the closing process first of all
beginning with the position according to FIG. 2, in which the
breech bolt has already been pushed shut but has not yet been
locked. This locking is accomplished by a downward swiveling of
bolt handle 14 by about 65.degree., whereby the bolt handle is
guided in a conventional guide slot of the receiver 11. Locking
element 13 is turned with the bolt handle, so that the spreading
cams 19 carried by neck 17 of the locking element are turned to a
position below the spreaders 15 and will cam the latter outwards
into annular groove 20 by means of the slanted transition surfaces
19b.
The force exerted during recoil on bolt 12 is transferred to the
receiver 11 by way of the spreader elements being in almost axial
alignment and by way of the relatively large supporting surfaces of
the spreader elements.
Upon opening the breech, the movements take place in a reverse
sequence, with the handle 14 being raised. Control disk 21 now acts
with the marginal surface 21c of its recess 21a and with
projections 21b to exert an inward force on the projections 15a of
the spreaders to pivot the latter inwardly. After completion of the
65.degree. turning movement of the locking element to force the
spreaders 15 completely out of groove 20, the locking element can
then be withdrawn from the receiver together along with the bolt so
that, for example, an additional cartridge can be moved into the
barrel. As soon as the rear end of latch 26 emerges during this
time from the bore of receiver 11, its front end will be forced
into groove 24 of the neck of the locking element and will prevent
mutual turning of bolt 12 and element 13 of the breech mechanism.
During the pushing in of the breech bolt, latch 26 is again pivoted
out of the longitudinal groove 24 automatically by the wall of the
bore of receiver 11 and counter to the force of spring 27.
MAJOR ADVANTAGES AND SCOPE OF THE INVENTION
Due to the fact that the present invention provides a rotatable,
rather than axially shiftable, cam 19, 19b for spreading the
spreaders, the bolt may be designed with reduced overall
length.
With the provision of means 21 for positively shifting the
spreaders to a retracted state, there is no need to provide springs
or a special cam surface arrangement between the spreaders and
locking recess to cause the spreaders to be shifted inwardly in
response to the bolt being pulled back. Such a special cam surface
arrangement tends to present a less efficient transfer of force
from the bolt to the receiver and necessitates the use of
additional locks such as at 45 in the afore-mentioned U.S. Pat. No.
2,601,808. Thus, the surface arrangement between spreaders 15 and
the groove 20b according to this invention may be designed for
optimum transfer of forces.
Although the invention has been described in connection with a
preferred embodiment thereof, it will be appreciated by those
skilled in the art that additions, modifications, substitutions and
deletions not specifically described may be made without departing
from the spirit and scope of the invention as defined in the
appended claims.
* * * * *