Improvements in the Breech Mechanism of Automatic and other Fire-arms.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Breech Mechanism of Automatic and other
Fire-arms.
I, HUGH WILLIAM GABBETT-FAIRFAX, of 107, Lambeth Palace Road, London,
S.E., Civil Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to breech mechanism of the kind in which there is
employed a sliding breech-block provided with a rotative locking head having
screw threads or radial projections which, when the breech is closed and an
angular movement imparted to the said head engage with similar threads or
projections in the barrel and so lock the block thereto. The said invention is
especially applicable to breech-blocks such as are described in the specification
of my prior patent No. 18686 of the year 1895.
According to my present invention I so construct the breech block that its
parts are held together by a single pin or key which can be readily removed when
desired to disconnect the parts. I also dispense with the depending lug or arm
with which the fixed head of the block was provided in accordance with the
specification of my aforesaid patent, whereby I avoid the slotting of the breech
end of the barrel and the consequent weakening thereof.
I furthermore form the rear end of the cylindrical piece or spindle that carries
the said rotative locking head, in such a manner that the hammer when released
to fire the weapon will act upon said cylindrical piece or spindle, if the rotative
head has not effectually engaged with the projections in the barrel, and cause
such engagement to be completed. Or if for any reason the rotative head has
failed to perform its angular movement sufficiently to effect the aforesaid com-
pleted engagement, the hammer will be prevented from striking the firing pin
and the discharge of the weapon will be prevented. I also, according to my
present invention provide means for enabling a longer recoil spring and longer
breech-block springs to be employed than heretofore.
For the purpose of my invention the various parts composing the breech-block
are adapted to fit one into the other longitudinally, that is to say the outer
portion or casing receives the cylindrical piece or spindle of the rotative head,
the said cylindrical piece or spindle receives the stem of the stationary head and
the said stem receives the firing pin.
These various parts are held together by a slotted or bifurcated pin or key
which passes transversely through the parts in such a manner that the cylindrical
piece or spindle of the rotative head can turn angularly without shifting longi-
tudinally, the stem of the stationary head can shift neither longitudinally nor
angularly and the firing pin can shift longitudinally to a limited extent without
turning angularly. The bifurcated portion of the pin or key embraces the firing
pin which is flattened at this part, such flattened part permitting the pin to

page_text: shift longitudinally to the requisite extent to fire the weapon but preventing it
from becoming detached or turning angularly as already stated. To enable
the cylindrical piece or spindle of the rotative head to turn, it is formed with a
segmental slot through which the said pin or key passes. I prefer that the
lower or bifurcated end of the pin or key should not extend completely through
the breech-block, so as to avoid interference with the smoothness of the lower
surface of the breech block.
The upper end of said pin or key may be formed with a notch and the con-
tiguous portion of the breech-block may be cut away to permit of the insertion of
the thumb nail or a suitable instrument into said notch for removing the pin or key
to disconnect the parts.
Although I prefer to employ a bifurcated pin or key as above stated, I may,
if desired use a plain pin of rectangular or semi-circular cross section, in which case
it will occupy such a position that one of its flat sides will lie against the flattened
portion of the firing pin.
Instead of providing the stationary head with a depending lug, I dispense
therewith as stated above and form the outer portion or casing of the breech
block with a longitudinal pin which is prolonged horizontally in a direction
towards the breech end of the barrel, thereby producing a finger which serves
the same purpose as that of the depending lug viz:-to push the cartridges from
the feed apparatus into the barrel, but in this case the finger occupies such a
position that it lies outside the barrel when the breech is closed, the said barrel
being left intact i.e. without a slot for the passage of the finger.
The aforesaid cylindrical piece or spindle carrying the rotative head extends
completely through the breech block and is formed at its rear end with a
transverse slot or recess. If the hammer be arranged vertically this recess
assumes a vertical position when the locking head is properly engaged with the
barrel, and when in such position the hammer will freely enter the said recess
to reach the firing pin.
If however the rotative head should have failed to completely engage with the
threads or projections in the barrel, the said recess will not occupy its vertical
position with the result that when the hammer is released to fire the weapon,
it will be unable to enter the said recess; and consequently will not act on the
firing pin to fire the weapon. It will be found advantageous to form the walls
of said recess somewhat inclined so that if the recess should be almost but not
quite in its vertical position owing to the rotative head having only partially
engaged with the threads or projections in the barrel, the hammer when released
will act on said inclined walls and force the recess into its proper vertical position
and thereby cause the completion of the locking of the block to the barrel to
take place and at the same time fire the weapon.
The aforesaid rotative locking head may receive its movement by a radial arm
working in a fixed incline as set forth in the aforesaid prior specifi-
cation or by a spring controlled drum as set forth in the specification of a
subsequent application for patent No. 21664 of the year 1896 or in any other
suitable manner.
It will be obvious that instead of forming a recess in the spindle of the rotative
head for the hammer to enter, I may provide said spindle or its radial arm with
a lug or projection for the hammer to act on.
The projections or lugs which are formed within the barrel for the correspond-
ing projections or lugs on the locking head to engage with, may be made of less
thickness without decreasing their strength, by forming them with webs that
extend longitudinally into the interior surface thereof. The projections or lugs
on the rotative locking head may also be made of less thickness without reduction
of their strength, by webs.
For enabling long springs as aforesaid to be employed, I provide the breech
block and the casing of the weapon with long spring cases, so that the extent
to which such springs have to be compressed is diminished with the result that

page_text: the force required for their compressing is reduced. The case of the recoil spring
is also prolonged for a similar purpose.
Dated this 14th day of July 1897.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C. Agents for the Applicant.
Improvements in the Breech Mechanism of Automatic and other
Fire-arms.
I, HUGH WILLIAM GABBETT-FAIRFAX, of 107, Lambeth Palace Road, S.E.,
Civil Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
n and by the following statement:—.
This invention relates to breech mechanism of the kind in which there is
employed a sliding breech-block provided with a rotative locking head having
screw threads or radial projections which, when the breech is closed and an
angular movement imparted to the said head engage with similar threads or
projections in the barrel and so lock the block thereto. The said invention is
especially applicable to breech mechanism having a breech block of the kind
described in the specincation of my prior patent No. 18,686 of the year 1895.
According to my present invention I so construct the breech block that its
parts are held together by a single pin or key which can be readily removed when
desired to disconnect the parts. I also dispense with the depending lug or arm
with which the fixed head of the block was provided in accordance with the
specification of my aforesaid patent, whereby I avoid the slotting of the breech
end of the barrel and the consequent weakening thereof.
I furthermore form the rear end of the cylindrical piece or spindle that carries
the said rotative locking head, in such a manner that the hammer when released
to fire the weapon will act upon said spindle, if the rotative head has not effectually.
engaged with the projections in the barrel, and cause such engagement to be
completed. Or if for any reason the rotative head has failed to perform its
angular movement sufficiently to effect the aforesaid complete engagement, the
hammer will be prevented from striking the firing pin and the discharge of
the weapon will be prevented.
In order that my said invention may be clearly understood and readily carried
into effect, I will proceed to describe the same more fully with reference to the
accompanying drawings, in which:-
Figure 1 is a sectional elevation shewing my improvements applied to a pistol
of the kind set forth in my aforesaid prior specification.
Figure 2 is a vertical section; Figure 3 a horizontal section; and Figure 4
a transverse section on the line 1, 1, of Figure 2, shewing the breech block
detached from the fire-arm.
Figures 5, 6 and 7 are elevations of the rear end of the breech block shewing
the rotative spindle in several positions hereinafter referred to.
Figure 8 is a plan of the firing pin removed from the breech block.
Figure 9 is a transverse section similar to Figure 4 but shews a modified
construction of the locking pin or key.
Figure 10 is an elevation of the rear end of the breech block somewhat modified.
Figures 11 and 12 are respectively a plan and rear end view of the breech
block shewing modified means for preventing the hammer from striking the
firing pin unless the breech block be properly locked to the barrel.

page_text: Figures 13 14 and 15 are respectively a vertical section an end view and
a cross section on 2, 2 of Figure 13 shewing a modified construction of the pro-
jections or locking lugs on the barrel.
A is the barrel; B the breech block; C the cartridge magazine; and D the
hammer.
The outer portion or casing 6 of the breech block is adapted to receive a
cylindrical piece or spindle 6¹ carrying the rotative head 63. The said spindle
receives the stem 63 of the stationary head 64, which stem in turn receives the
firing pin 65. These various parts are adapted to enter one within the other
as represented in the drawings and are held together by the bifurcated pin
or key 66 which passes transversely through the parts in such a manner that the
cylindrical piece or spindle 61 carrying the rotative head can shift angularly
without independent longitudinal movement. The stem 63 of the stationary head
can shift neither longitudinally nor angularly, and the firing pin 65 can shift
longitudinally to a limited extent without turning angularly. The bifurcated
portion of the key 66 embraces the firing pin which at such part is flattened
as shewn at 6', this flattened part permitting the firing pin to move longitudinally
to the requisite extent to fire the weapon but preventing it from becoming
detached or turning angularly as above stated. To enable the cylindrical piece
or spindle 6 of the rotative head 62 to turn, it is formed with segmental slots 68 68
through which the said key 66 passes. I prefer that the inner or bifurcated end
of the said key should not extend completely through the breech block, so as
to avoid interference with the smoothness of the lower surface of the latter.
The upper end of the said key is formed with a notch 69 and the contiguous
portion of the breech-block is cut away at 610 to permit of the insertion of the
thumb nail or a suitable instrument into said notch for removing the pin or
key to disconnect the parts.
Although prefer to employ a bifurcated pin or key as above stated, I may,
if desired use a plain pin of circular rectangular (or semi-circular) cross' section
as shewn at Figure 9 in which case it will occupy such a position that one of its
flat sides will lie against the flattened portion 67 of the firing pin.
Instead of providing the stationary head 64 with a depending lug, as described
in my aforesaid prior specification I dispense therewith as stated above and
form the outer portion or casing 6 of the breech block with a longitudinal
pin or projection 6 which is prolonged horizontally in a direction towards the
breech end of the barrel, thereby producing a finger which serves the same
purpose as that of the depending lug viz.:-to push the cartridges from the
feed apparatus into the barrel, but in this case the finger occupies such a position
that it lies outside the barrel when the breech is closed, (see Figure 1) the said
barrel being left intact i.e. without a slot for the passage of the finger.
The aforesaid cylindrical piece or spindle b₁ carrying the rotative head 6ª
extends completely through the breech block casing 6 and is formed at its rear
end with a transverse slot or recess 612. If the hammer D be arranged vertically
as shewn in Figure 1 this recess assumes a vertical position when the locking
head is properly engaged with the barrel, and when in such position the hammer
will freely enter the said recess to reach the firing pin.
If however the rotative head should have failed to completely engage with
the threads or projections in the barrel, the said recess will not. occupy its
vertical position, with the result that when the hammer is released to fire the
weapon, it will be unable to enter the said recess, and consequently will not act
on the firing pin to fire the weapon. It will be found advantageous to form
the walls of said recess somewhat inclined as illustrated in Figures 5, 6 and 7
so that if the recess should be almost but not quite in its vertical position owing
to the rotative head having only partially engaged with the threads or projections
in the barrel, the hammer when released will act on said inclined walls and
force the recess into its proper vertical position and thereby cause the completion
of the locking of the block to the barrel and at the same time fire the weapon.
"

page_text: The aforesaid rotative locking head receives its movement by the radial arm B
working in conjunction with an incline and switch as set forth in the aforesaid
prior specification or by a spring controlled drum as set forth in the specification
of a subsequent patent No. 21664 of the year 1896 or in any other suitable
manner.
Instead of forming a recess 612 in the spindle of the rotative head for the
hammer to enter as above stated, I may provide the said spindle with a lug or
projection 613 for the hammer to act on, as illustrated at Figure 10. Or the radial
arm B may be furnished with a rearward extension B1 (see Figures 11 and 12)
having a curved arm B2 carrying a segmental block B³.
The projections or lugs a which are formed within the barrel for the corre-
sponding projections or lugs on the locking head to engage with, may be made
of less thickness without decreasing their strength, by forming them with webs a¹
that extend longitudinally into the interior surface thereof as shewn at Figures 13
to 15. The projections of lugs on the rotative locking head may also be made
in a similar manner.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is :-
1. The construction of the breech block so that its various parts are held
together by a single pin or key substantially as described and for the purpose
specified.
2. The construction of the breech block with a horizontal projection or finger
which acts, in conjunction with an incline, to push the cartridges from the feed
apparatus into the barrel substantially as described and for the purpose specified.
3. The combination with the rotative portion of the breech block of means
substantially as described for preventing the hammer's striking the firing pin
unless the block be effectually locked to the barrel.
4. The construction of the locking lugs of the breech block and the barrel
substantially as described and for the purpose specified.
5. A breech block having its parts constructed arranged and combined to
operate substantially as described with reference to the accompanying drawings
and for the purposes specified.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.