IMPROVEMENTS IN BREECH LOADING SMALL ARMS
Year: 1884

page_text: "
I JOHN FIELD SWINBURN of Russell Street Birmingham in the County of
Warwick Gun Manufacturer do hereby declare the nature of the said Invention for
'IMPROVEMENTS IN BREECH LOADING SMALL ARMS to be as follows:-
"
My invention has reference to drop down breech loading small arms and consists
principally of the mechanism herein after described for preventing the accidental
falling of the hammers of the said drop down small arms on the breaking of or
injury to the sear or by the wearing of the bent or by the jarring of the sear out
of the bent.
The said mechanism is used in combination with the ordinary sear and consists
essentially of a second or supplementary sear for acting as a block to the hammer
should the ordinary sear fail to hold it in its cocked position. The said supple-
mentary or blocking sear is withdrawn out of action on the discharge of the gun
by the operation of the trigger upon it as hereinafter described. The said blocking
sear turns on a centre a little above and at the rear of that on which the ordinary
sear turns. The short or rear arm of the blocking sear is curved and bears upon
the blade of the trigger near the joint of the said trigger that part of the said
curved short arm under which the ordinary sear passes being cut away so that the
latter sear is not interfered with. The front or acting end of the blocking sear is
nearly vertical and is notched or cut away at top. The blocking sear is raised into
its blocking position by the action of an independent spring or by the spring of the
ordinary sear. On the inner side of the hammer and in a line with the acting end
of the blocking sear is a shoulder for the vertical end of the blocking sear to engage
with or bear against. On raising the hammer to full cock the tumbler of the
hammer bears against and depresses the front or acting end of the blocking sear
and as soon as the hammer has reached its fully cocked position and simultaneously
or nearly so with the engaging of the ordinary sear with its bent the blocking sear
snaps upon or against the shoulder at the side of the hammer thereby blocking the
On
said hammer and preventing its discharge should the ordinary sear fail to act.
pressing the trigger to discharge the gun the blocking sear is withdrawn from the
shoulder on the hammer by the action of. the blade of the trigger simultaneously
with the disengagement of the ordinary sear from the bent in the hammer.

page_text: I support the whole of the lock mechanism and the safety or blocking mechanism
on the trigger plate which has a forked end. At the middle of the trigger plate
and between the internal hammers is a block having an inclined face and the body
of the gun has at its rear end a block with an inclined face. The front end of the
body is undercut to receive lips at the extreme ends of the branches of the trigger
plate. By partly fitting these lips under the undercut cut or recessed parts of the
body and pressing the trigger plate into the body the inclined faces of the blocks
are seated together and a slight sliding forward of the trigger plate effected. Its
lips are thereby made to completely engage with the undercut parts of the body
thus fixing the trigger plate at its front end. By means of a screw passed through
the trigger plate and made to take into the block on the body the trigger plate is
fixed to the body at its rear end. The fixing of the trigger plate is thus effected
by the use of a single screw.

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COMPLETE
DIECIFICATION.
I JOHN FIELD SWINBURN of Russell Street, Birmingham, in the County of
Warwick Gun Manufacturer, do hereby declare the nature of my Invention for
'IMPROVEMENTS IN BREECH LOADING SMALL ARMS" and in what manner the same
is to be performed to be particularly described and ascertained in and by the
following statement:―
My invention has reference to drop down breech loading small arms and consists
principally of the mechanism herein after described for preventing the accidental
falling of the hammers of the said drop down small arms on the breaking of or
injury to the sear or by the wearing of the bent or by the jarring of the sear
out of the bent.
The said mechanism is used in combination with the ordinary sear and consists
essentially of a second or supplementary sear for acting as a block to the hammer
should the ordinary sear fail to hold it in its cocked position.
The said supplementary or blocking sear is withdrawn out of action on the
discharge of the gun by the operation of the trigger upon it as herein after
described.
The said blocking sear turns on a centre a little above and at the rear of that
on which the ordinary sear turns. The short or rear arm of the blocking sear is
curved and bears upon the blade of the trigger near the joint of the said trigger,
but that part of the said curved short arm under which the ordinary sear passes is cut
away so that the latter or ordinary sear is not interfered with by the said short arm.
The front or acting end of the blocking sear is nearly vertical and is notched or cut
away at top. The blocking sear is raised into its blocking position either by the
action of an independent spring or by the action of the trigger. On the inner side
of the hammer and in a line with the acting end of the blocking sear is a shoulder
for the vertical end of the blocking sear to engage with or bear against. On
raising the hammer the tumbler of the hammer bears against and depresses the
front or acting end of the blocking sear and before the hammer has reached its fully
cocked position and simultaneously or nearly so with the engaging of the ordinary
sear with its bent, the blocking sear snaps upon or against the shoulder at the side
of the hammer, thereby blocking the said hammer and preventing its discharge
should the full cocking not have been effected or the ordinary sear fail to act. On
pressing the trigger to discharge the gun the blocking sear is withdrawn from the
shoulder on the hammer by the action of the blade of the trigger simultaneously
with the disengagement of the ordinary sear from the bent in the hammer.
I support the whole of the lock mechanism and the safety or blocking mechanism
on the trigger plate which has a forked end. At the middle of the trigger plate
and between the internal hammers is a block having an inclined face and the body
of the gun has at its rear end a block with an inclined face. The front end of the
body is undercut to receive lips at the extreme ends of the branches of the trigger
plate. By partly fitting these lips under the undercut or recessed parts of the body
and pressing the trigger plate into the body the inclined faces of the blocks are
seated together and a slight sliding forward of the trigger plate effected. Its lips
are thereby made to completely engage with the undercut parts of the body thus

page_text: fixing the trigger plate at its front end. By means of a screw passed through the
trigger plate and made to take into the block on the body, the trigger plate is
fixed to the body at its rear end. The fixing of the trigger plate is thus effected
by the use of a single screw.
Figures 1 and 2 represent in longitudinal section partly in elevation, the breech
end of a double barrel drop down gun containing my improvements, Figure. I
representing the hammers discharged and Figure 2 the hammers nearly in their
cocked position with the supplementary sear in action; Figure 3 represents an end
elevation of the body and Figure 4 a plan of underside and longitudinal section of
the same; Figure 5 represents in side elevation; Figure 6 in plan and section and
Figure 7 in longitudinal, section, the trigger plate carrying the whole of the lock,
safety and blocking mechanisms, the hammers in Figures 5 and 6 being in the
same position as in Figure 1 and the hammers in Figure 7. being in the same
position as in Figure 2; Figure 8 represents one of the blocking sears and
Figure 9 one of the hammers détached.
The same letters of reference indicate the same parts in the several Figures of
the Drawings.
I will first describe the hammer blocking mechanism and parts connected
with it.
a, a are the internal hammers; b, b the ordinary sears and c c the safety or
supplementary sears for acting as blocks to the hammers a, a should the ordinary
sears b, b fail to hold the hammers in their cocked position; c² is the centre on
which the blocking sears turn the said centre being situated a little above and at
the rear of the centre 62 on which the ordinary sears b, b turn; e is the short or
rear arm of the blocking sear the said short arm e bearing upon the blade of the
trigger near the joint be as best seen in Figure 7 so that on lifting the trigger
the latter operates upon the said short arm e and takes the blocking sear out of
action.
'
It will be seen by an examination of the end elevation of the blocking lever
represented in Figure 8 that part of the short arm e is cut away so that the
ordinary sear is not interfered with by the said short arm. The front or acting end
of the blocking sear is nearly vertical and is notched or cut away at top as repre-
sented in the drawing; g is the spring by which the blocking sear, is raised into
its blocking or acting position, the curved outer end of the spring g taking a
bearing on a support at the middle of the trigger plate (see Figure 6); i is the
.shoulder on the inner side of the hammer a and in a, line with the acting end of
the blocking sear c for the vertical end of the blocking sear to engage with or bear
against.
Although I prefer to use a spring to lift the blocking sear into its blocking
position yet the said spring may be omitted, the blocking sear in this case being lifted
by the trigger. When the gun has been discharged the blocking sear occupies the
position represented in Figures 1, 5 and 6. In raising the hammer to full cock the
shoulder i on the said hammer bears against and depresses the front or acting end
of the blocking sear c and before the hammer has reached its fully cocked position
and simultaneously or nearly so with the engaging of the ordinary sear b with the
bent the acting end of the blocking sear rises by the action of its spring g and
snaps upon or against the shoulder i at the side of the hammer as represented in
Figures 2 and 7. The hammer is thereby blocked and its accidental discharge
prevented should the full cocking not have been effected or the ordinary sear fail
to act:
When the trigger f is pulled to discharge the gun the blocking sear c is with-
drawn from the shoulder i (the acting end being depressed by the action of the
blade of the trigger on the short arm e) simultaneously or nearly so with the
disengagement of the ordinary sear b from the bent in the hammer.
In order to give additional safety to the gun so that it cannot be discharged by
the ordinary pull upon the trigger unless the hammer has been fully cocked I so
arrange the ordinary sear with respect to the blade of the-trigger f that the latter

page_text: cannot operate upon the ordinary sear except by a long pull. In Figures 2 and 7
it will be seen that the hammer has not been fully cocked and the sear 6 has not
engaged with the bent. When the parts are in this position the blocking searc
holds the hammer in a safety position and as the tail end of the sear 6 has not
reached the blade of the trigger the pulling of the trigger in the ordinary way does
not discharge the gun. When the hammer is fully cocked the ordinary sear enters the
bent and its tail end is brought against the blade of the trigger as seen in Figure 1
so that the lifting of the trigger first withdraws the blocking sear and afterwards
the ordinary sear.
I will now describe my arrangement for supporting the mechanism on the trigger
plate and fixing the trigger plate in the body.
is the trigger plate supporting the whole of the lock, safety and blocking
mechanism the fore end of the said trigger plate being forked, the forked parts
being marked ², k² the said forked parts supporting the main springs of the
hammers a, a. The front ends of the forked parts have lips or shoulders k³, l³;
Zis a block at the middle of and between the hammers a, a the face of which block
is inclined. The body m of the gun is made hollow and of a figure proper to
receive the trigger plate and the parts carried by the trigger plate. That is to say,
the front of the body m has channels at m², m² for the forked parts k², 2 of
the trigger plate to occupy and the rear part of the body m is recessed at m³ for
receiving the hammers a, a. The front ends of the channels m², m² are undercut.
In the rear part of the body m is a block p the face of which is inclined for the
inclined face of the block of the trigger plate to bear against.
In connecting the trigger plate / to the body m of the gun, the lips or shoulders
kles of the trigger plate are first partly fitted in the recessed or undercut parts at
the ends of the channels m³, m³ in the body m and the trigger plate k is then
pressed into the body. As the trigger plate enters the body, the inclined face of
the block on the trigger plate seats itself against the inclined face of the block p
on the body and a slight sliding forward of the trigger plate is thereby produced..
Its lips or shoulders, at k³ ³ are by this forward motion made to completely engage
with the undercut parts at the ends of the channels m², m² in the body m, thus fixing
the trigger plate at its front end. By means of a screw passed through the hole q in
the trigger plate and made to take into a screwed hole r in the block p on the
body, the trigger plate is fixed to the body at its rear end the fixing of the trigger
plate being thus effected by the use of a single screw.
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 of Improvements in drop down breech loading small arms
First The combination with the ordinary sear of the lock mechanism, of a
second or supplementary sear marked c, e for acting as a block to the hammer, the
said hammer being furnished with a side shoulder for the vertical end of the.
blocking sear to engage with or bear against, the said second or blocking sear
being arranged with respect to the ordinary sear and trigger and constructed and
acting substantially as herein before described and illustrated in the accompanying
Drawings.
Secondly-The construction and arrangement of parts herein before described and
illustrated in the accompanying Drawings for connecting the trigger plate sup-
porting the whole of the lock and safety mechanism to the body of the small arm.
Dated this Fighth daw of Ta
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