Improvements in the Breech Mechanism of Automatic and other Fire-arms.
Year: 1898

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 more particularly to breech mechanism of the kind in
which there is employed a rectilinear reciprocating breech-block provided with
a rotative locking head having radial or other projections or lugs which, when
the breech is closed and an angular movement imparted to the said head, engage
with corresponding projections or lugs in the barrel and so lock the block thereto.
According to my invention the rotative locking head of the breech block is
formed in two parts, each part having two diametrically arranged radial pro-
jections, the said parts being so arranged that the radial projections on one part
will lie behind the radial projections on the other part when the breech block is
in its unlocked position. When however the breech block occupies its locked
position, that is to say when the locking head has entered the barrel, the said
radial projections separate and thereby form four locking pieces for engagement
with the barrel. This enables me to form only two slots or recesses in the breech
end of the barrel instead of four which were necessary in the fire-arm described in
the Specification of my prior Patent No. 18686 of 1895. The barrel can thus be
made stronger than heretofore with a greater efficiency of the locking.
The separation of the aforesaid locking projections or lugs may be effected by
causing the two parts of the locking head to shift angularly in opposite directions
by means of two radial arms, one for each of the parts of the locking head, such
arms being actuated against the resistance of a spring by suitably arranged in-
clines as the breech block reciprocates.
The aforesaid inclines may be two in number (one on each side of the breech
block) and may take the form of plates having inclined slots for the said radial
arms to engage with.
Or the said radial arms on the breech block may be actuated by a bar or bars
formed with inclines, the said bars travelling with the breech block but being
capable of having a certain amount of independent motion. On recoil each radial
arin would ascend the incline of the said bar and the block be thus unlocked from
the barrel, then on the forward movement of the breech block the said bar travels
with it until stopped by an appropriate device; the radial arm. then descends
the incline under the influence of a spring and so locks the block to the barrel.
Or the radial or other arms of the breech block may be arranged to protect
through longitudinal slots formed in a sleeve to which the barrel is connected,
such slots being provided with downward extensions at their front ends for the
said arms to enter under the influence of springs or otherwise when the breech
block is locked to the barrel. The casing in which the said sleeve slides is also
furnished with inclines up which the said arms on the breech block rise during

page_text: recoil and thereby effect the unlocking movement, the said inclines having
horizontal ledges at their upper ends upon which ledges the said arms are sup-
ported in their unlocking position.
I do not confine myself to the use of only two pairs of lugs or projections on the
locking head of the breech block; I may if desired increase this number. In
most cases however two pairs of lugs will be found the most suitable.
Datad this 10th day of Anril 1000
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, formerly of 107, Lambeth Palace Road,
London, S., but now of 47, Portland Street, Leamington, in the County of
Warwick, 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 ascer-
tained in and by the following statement:-
This invention relates more particularly to breech mechanism of the kind in
which there is employed a rectilinear reciprocating breech-block or bolt provided
with a rotative locking head having projections or lugs which, when the breech
is closed and an angular movement imparted to the said head, engage with corres-
ponding flanges, projections or lugs in the barrel and so lock the block thereto.
According to my invention the rotative locking head is formed in two parts,
each part having two diametrically disposed radial lugs, the said parts being so
arranged that the lugs on one part will lie behind the lugs on the other part when
the breech block is in its unlocked position. When however the breech block
occupies its locked position, the said lugs separate and thereby form four locking
pieces for engagement with the barrel. This device enables two slots or recesses
in the breech end of the barrel to serve instead of four which were necessary in
the fire-arm described in the Specification of my prior Patent No. 18686 of 1895.
The barrel can thus be made stronger and capable of more effectually locking the
breech block than heretofore.
The separation of the aforesaid lugs is preferably effected by causing the two
parts of the locking head to shift or turn angularly in opposite directions by
means of two radial arms, one on each of the parts of the locking head, such arms
being moved against the resistance of a spring by suitably arranged guides as
the breech block reciprocates or moves to and fro in opening and closing the breech.
I do not confine myself to the use of only two pairs of lugs on the locking head
of the breech block; I may if desired increase this number. Generally however
two pairs of lugs will be found efficient and convenient.
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 side elevation of a portion of an automatic pistol with my herein
described improvements applied thereto.
Figure 2 is a side elevation of the breech-block detached from the pistol.
Figure 3 is a front end elevation of the said breech block.
Figure 4 is a rear end elevation of the said breech block.

page_text: Figure 6 is an end elevation of the said body.
Figure 7 is a longitudinal section of a ring or sleeve with which the breech
block is surrounded, and
Figure 8 is an end view thereof.
Figure 9 is a transverse section on the line 1, 1, of Figure 1, and
Figure 10 is a transverse section on the line 2, 2 of Figure 1 shewing the slots
in the breech end of the barrel through which the lugs on the breech block pass
when the latter closes the breech.
A is the barrel, and A¹ the spiral spring by which it is caused to assume its
firing position after each discharge. B is the body of the breech block and B'
the firing pin. C is the rotative locking head of the breech block, which head is
formed in two parts one carrying the lugs c and the other the lugs c¹. The part
carrying the lugs c has a stem entering the body of the breech block and the
part carrying the lugs c¹ is formed in one piece with the said body. Within a
cavity 6 in the body is a spiral spring 3 (Figure 2) surrounding the stem c³, one
end of such spring being connected to the body and the other end to the stem so
that the torsion of the spring tends always to cause the two parts of the rotative
head to turn and occupy the position represented in Figure 3. Projecting in
opposite directions from the breech block are the radial arms 6 c, the arm b*
being on the body of the breech block and the arm on the stem: these arms
extend through slots a formed in the tubular extension or sleeve A2 of the barrel.
The body is formed with a segmental groove 61 for. the arm to work in.
The frame D of the pistol within which the barrel and its tubular extension
or sleeve A² reciprocate at each discharge, is furnished with two guides having
inclined portions d, these guides being located one on each side of the sleeve in
the path of the said radial arms. Instead of these guides I may employ the
switch and inclines set forth in my Specifications of prior Patents No. 18686 of
1895 and No. 17672 of 1896.
When the barrel and its sleeve A³, together with the breech block, recoil, the
said radial arms are raised by travelling along the inclined portions of the
guides and are thereby removed from the vertical portion a¹ of the said slots a
and permitted to lie upon the horizontal portion of the said guides. This
angular movement of the radial arms shifts the two pairs of projections c, c¹, from
the locking position in which they are represented in Figure 3 and brings them
one immediately behind the other so that they will pass through the slots a³
(Figure 10) in the breech chamber of the barrel. The breech block is retained
in its recoiled position, by means analogous to those set forth in my prior Specifi-
cation No. 18686 of 1895, while the barrel returns to its firing position under
the influence of the spring A', the empty cartridge case being ejected and a fresh
cartridge brought into leading position as is well understood. As the barrel com-
pletes its forward movement it releases the breech block which advances to close
the breech under the influence of a spring or springs not shewn in the drawings,
thereby pushing the new cartridge into the barrel and causing the locking lugs to
pass through the slots a². The radial arms b c at this time have travelled for-
ward with the breech block along the slots a and have arrived above the vertical
rortions of the said slots into which portions, under the torsional action of
the spring 3, said arms descend and so shift the locking lugs c d angularly in
opposite directions, whereby they separate and come behind the flanges a³ of the
barrel as shewn by the dotted lines in Figure 10.
In order to permit the stem c³ to be conveniently connected to the body of the
breech block so that said stem will freely turn therein without becoming unin-
tentionally detached. I provide its inner end with a projection to engage with
a segmental groove in the body of the breech block. There is an internal
longitudinal groove 63 (Figure 5) formed in the breech block to enable the said
projection to pass along and reach the segmental groove. By giving the stem

page_text: an angular movement after the projection reaches the said segmental groove the
parts engage and become connected together in such a manner that the stem (3
can move angularly to the required extent within the body B but cannot move
longitudinally with respect thereto. The segmental groove 62 is of such a length
that the angular movement of the stem during the working of the parts will
not be sufficient to bring the said projection c into alignment with the said longi-
tudinal groove b³.
In a similar manner the body of the breech block is connected to the surrounding
ringe by a projection 6 on the body engaging with a segmental groove e¹ in said
ring, the latter being formed with a longitudinal groove e² for enabling the pro-
jection to reach said segmental slot. The ring may be flattened on its exterior
at ee to conform to the internal shape of the sleeve A2 (see Figure 9) so that
said ring will slide in the sleeve without turning. The said ring may however
be otherwise constructed to prevent its turning.
.
The aforesaid radial arms bx c may be furnished with knobs at their outer
ends to permit the breech block to be operated by hand when desired. I.
Instead of arranging the said lugs c c¹ to lie one behind the other as described
and shewn I may arrange them to lie one by the side of the other.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I claim
is:―
1. A longitudinally sliding breech-block in which the locking lugs are adapted
to move angularly in opposite directions in assuming their locking and unlocking
positions for the purpose specified.
2. A fire arm having a breech block constructed and operating substantially
as described with reference to the accompanying drawings for the purpose specified.
Dated this 18th day of February 1899
HASELTINE, LAKE & Co.,
45, Southampton. Buildings, London, W.C.,
Agents for the Applicant.