IMPROVEMENTS IN BREECH LOADING SMALL ARMS
Year: 1880

page_text: LETTERS PATENT to John Field Swinburn, of Birmingham, in the County of
Warwick, Gun Manufacturer, for an Invention of "IMPROVEMENTS IN
BREECH LOADING SMALL ARMS."
PROVISIONAL SPECIFICATION left by the said John Field Swinburn at the
Office of the Commissioners of Patents on the 21st October 1880.
JOHN FIELD SWINBURN, of Birmingham, in the County of Warwick, Gun
Manufacturer. "IMPROVEMENTS IN BREECH LOADING SMALL ARMS."
My Invention relates, first, to breech loading small arms of the kind called drop
down guns, in which the breech ends of the barrels are locked down for firing the
gun by means of a bolt or bolts, which said bolts are withdrawn for unlocking the
barrels by the action of a spring lever on the tang of the break off,
In the ordinary method of constructing the said spring lever and parts imme-
diately connected therewith the return of the said lever to its normal position is
effected by a spring situated underneath the tank of the break off, the connection
of the said spring with the said lever being effected through a slot in the tang.
This method of construction necessitates the making of a slot in the tang, and also
the cutting away of a portion of the stock, thereby weakening those parts and
involving the expenditure of much skilled labour.
In constructing and arranging the parts of the said spring lever, and parts
immediately connected therewith, I make a recess on the underside of the said
lever, extending nearly the whole length of the said lever. In this recess the
spring which effects the return of the lever to its normal position is situated. On
the upper edge of the break off, and near the centre on which the lever turns, is a
fixed bearing upon which the free end of the spring bears, and when the lever is
turned aside the spring is brought into a state of tension, and tends to restore the
lever to its normal position. By this arrangement the necessity for making a slot
in the tang and cutting away the wood of the stock to make room for the spring is
done away with.
My Invention relates, secondly, to the fore end fasteners of drop down guns,
and consists in constructing and arranging the parts of the said fasteners in the
Date 071

page_text: following manner-In the bar of the fore end I make a slot, into which the loop on
the barrel takes as usual when the fore end is shut down on the barrel. On the
side of this bar is a spring, which carries near its free end a pin, the inclined end
of which projects into the said slot. The free end of the spring terminates in an
incline. In the outer end of the bar a sliding rod or pusher works. The outer
end of this rod protrudes from the outer end of the fore end, and is provided with
a thumb plate for pressing it inwards. The inner end of the sliding rod terminates
in an incline, which bears against the incline on the end of the spring. When the
fore end is shut down the slot in the bar passes onto the loop on the barrels, the
inclined pin of the spring snapping into a hole in the loop, and fastening down the
fore end.
When it is wished to liberate the fore end the thumb plate on the end of the
sliding rod is pressed inwards; the incline on the end of the said rod acting on the
incline on the end of the spring forces back the free end of the spring, thus with-
drawing the inclined pin of the said spring from the loop and liberating the "fore
end."
Instead of one spring on one side of the bar of the break off two springs may be
employed, one on one side and the other on the opposite side of the bar.
My Invention consists, thirdly, of the following arrangements of safety apparatus
for preventing the accidental discharge of drop down guns:-
According to one arrangement I employ a sliding rod passing through the body
of the gun in a line parallel with the axes of the barrels when shut down for firing.
The fore end of the rod enters the recess in which the lump works, and the rear
end, which protrudes from the stock, terminates in a thumb plate. When the
breech ends of the barrels are raised for charging, an auti-friction roller carried by
a spring on the lower part of the lump comes against the inner end of the said rod
and forces it back, a depending stop carried by the said rod being thereby brought
over the sears and locking them down. The unlocking of the sears preparatory to
firing is effected by pressing upon the thumb plate described.
According to another arrangement I modify in the following manner the ordinary
safety apparatus by which a bolt is brought over the ends of the triggers by the
act of grasping the gun for firing :-I shape the end of the said bolt so that when
it is shot over the triggers it also engages with the sears. Or I add to the ordinary
bolt a parallel spring bolt to engage with the scars, the elasticity of the said spring
bolt permitting of the slight motion of the scars occasioned by the cocking of the
gun, and thereby rendering unnecessary the slight play required when an inelastic
bolt is used.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Field Swinburn in the Great Seal Patent Office on the
16th April 1881.
JOHN FIELD SWINBURN, of Birmingham, in the County of Warwick, Gun
Manufacturer. IMPROVEMENTS IN BREECH LOADING SMALL ARMS,"
"
My Invention relates, first, to breech loading small arms of the kind commonly
called drop down guns, in which the breech ends of the barrels are locked down
for firing the gun by means of a bolt or bolts, which said bolts are withdrawn for
unlocking the barrels by the action of a spring lever on the tang of the break off.
In the ordinary method of constructing the said spring lever and parts imme-
diately connected therewith, the return of the said lever to its normal position is
effected by a spring situated underneath the tang of the break off, the connection
of the said spring with the said lever being effected through a slot in the tang.
This method of construction necessitates the making of a slot in the tang, and
also the cutting away of a portion of the stock, thereby weakening those parts and
involving the expenditure of much skilled labour.
In constructing and arranging the parts of the said spring lever, and parts imme-
diately connected therewith, I make a recess on the underside of the said lever,
extending nearly the whole length of the said lever. In this recess the spring
which effects the return of the lever to its normal position is situated. On tho
upper side of the break off, and near the centre on which the lover turns, is a fixed
bearing upon which the free end of the spring bears, and when the lever is turned
aside the spring is brought into a state of tension, and tends to restore the lever to
its normal position. By this arrangement the necessity for making a slot in the
tang and cutting away the wood of the stock to make room for the spring is done
away with.
Figure 1 of the accompanying Drawings represents in plan of upper side a
portion of a drop down gun containing this part of my Invention; Figure 2 repre-
sents a plan of underside of the spring lever detached; and Figure 3 represents a
longitudinal section of the same.
a is the spring lever situated on the tang of the break off and turning on the
centre b, and connected by the pin c to the sliding bolt d, which snaps into the
prolonged rib e between the barrels. In the underside of the said lever a is a recess
or box f, having the shape best seen in Figures 2 and 3. In this recess or box f
the spring g, which effects the return motion of the lever to its normal position, is
situated. It will be seen by reference to Figure 2 that the fixed end of the spring g
seats itself in the seat at f between and at one edge of the recess f, the free end of
the said spring taking a bearing against the stud (see Figure 1) near the centre b
on which the lever turns. This stud or bearing his affixed to the upper side of
the tang i of the break off.
When the lever a is turned aside for withdrawing the bolt & the spring g is
brought into a state of tension, and tends to restore the lever to its normal
position.
This part of my Invention may be applied to spring levers for working either
top sliding bolts or under sliding bolts of drop down guns.
My Invention relates, secondly, to the fore end fasteners of drop down guns, and
consists in constructing and arranging the parts of the said fasteners in the following
manner:-
In the bar of the fore end I make a slot, into which the loop on the barrel takes,
as usual, when the fore end is shut down on the barrel. On the side of this bar is
a spring, which carries near its free end a pin, the inclined end of which projects
into the said slot. The free end of the spring terminates in an incline. In the

page_text: outer end of the bar a sliding rod or pusher works. The outer end of this rod
protrudes from the outer end of the fore end, and is provided with a thumb plate
for pressing it inwards. The inner end of the sliding rod terminates in an incline
which bears against the incline on the end of the spring. When the fore end is
shut down the slot in the bar passes onto the loop on the barrels, the inclined pin
of the spring snapping into a hole in the loop and fastening down the fore end.
When it is wished to liberate the fore end the thumb plate on the end of the
sliding rod is pressed inwards; the incline on the end of the said rod acting on the
incline on the end of the spring forces back the fore end of the spring, thus
withdrawing the inclined pin of the said spring from the loop, and liberating the
fore end.
Instead of one spring on one side of the bar of the fore end two springs may be
employed, one on one side and the other on the opposite side of the bar.
Figure 4 represents in plan of upper side, and Figure 5 partly in horizontal
section, the fore end of a drop down gun in combination with the loop on the
barrels, to which fore end a fastener constructed according to my Invention is
applied.
Figure 6 represents in side elevation the bar of the fore end and the fastener.
In Figure 4 the fore end is represented fastened to the loop, and in Figure 5
unfastened from the loop; k is the bar of the fore end, and is the wooden part of
the same; m is the recess in the bar, into which the loop n on the barrels takes
when the fore end is shut down upon the barrels. Fixed at p² on each side of the
bar k is a spring or spring arm p, the free end of each spring terminating in an
incline p. Near the said incline p³ is an inclined locking stud 2, and in each side
of the loop n is a hole or recess of a size and shape proper for the stud p¹ to engage
in; q is the sliding rod or pusher for releasing the fastener. This pusher works in
a portion of the bar h, and its outer end projects from the outer end of the fore end,
and is furnished with a thumb plate or head q for pressing it inwards. The
return or back motion of the rod or pusher q is effected by the action of the
inclined ends p³, p³, of the springs p, p, upon the inclined inner end of the said rod
or pusher.
When the "fore end" of the gun is shut down upon the barrels the slot m in
the bar ke passes onto the loop n on the said barrels, and the said loop striking
against the inclined faces of the pins p, p, on the springs p, p, forces back the said
springs, and when the fore end has seated itself against the barrels the said
pins 22, snap into the holes or recesses in the loop n, and fasten the fore end to
the barrels, as illustrated in Figure 4.
To liberate the fore end the thumb plate or head q² on the end of the sliding
rod q is pushed inwards. The inner inclined end of the said rod q is thereby made
to act against the inclines p³, p³, on the springs p, p, and open out or force back
the free ends of the said springs. The studs p, p, are thus withdrawn from the
holes in the loop n, as illustrated in Figure 5, and the fore end is liberated and may
be removed.
A single spring of the kind represented may be used instead of the two springs
shown in the Drawing.
My Invention consists, thirdly, of the following arrangements of safety apparatus
for preventing the accidental discharge of drop down guns.
According to one arrangement I employ a sliding rod passing through the body
of the gun in a line nearly parallel with the axes of the barrels when shut down
for firing. The front end of the rod enters the recess in which the lump works,
and the rear end, which protrudes from the tang, terminates in a thumb plate.
When the breech ends of the barrels are raised for charging the lower part of the
lump comes against the inner end of the rod, and forces it back, a depending stop
or arm carried by the said rod being thereby brought over the sears, and locking
them down.
The unlocking of the sears, preparatory to firing, is effected by pressing upon
the thumb plate described.

page_text: This arrangement of my Invention is illustrated in longitudinal sections in
Figures 7 and 8, Figure 7 representing the sliding safety rod out of action, and
the sears at liberty to be raised for the discharge of the gun, and Figure 8
representing the said safety rod in action, and the sears locked down; Figure 9
represents in side elevation and plan the sliding safety rod detached from the gun;
Figure 10 represents a front elevation of the lump and portions of the barrels; and
Figure 11 represents a modification for connecting the thumb plate to the
safety rod.
The same letters indicate the same parts in Figures 7, 8, 9, 10, and 11.
a is the sliding safety rod passing through the body of the gun in a line
nearly parallel with the axes of the barrels when shut down. The front end of
the rod a enters, when the safety arm or stop e is out of action, the recess at b in
the body, in which recess the lump c on the underside of the barrels works, and
the said front end also takes into a seat at c² in the lump c on the barrels, and the
rear end of the said rod a passes through the tang of the break off, and carries a
thumb plate d, situated external to and sliding upon the said tang. On the said
sliding safety rod a is a curved stop or arm e, which can either be brought over the
cross arms of the sears f, as represented in Figure 8, or be removed from over the
said cross arms of the sears, as represented in Figure 7. A spring g fixed to
the underside of the tang of the break off presses upon the rod a, and retains it in
the position to which it has been moved, and also keeps the thumb plate d to its
bearing on the tang. At the front end of the safety rod a is an incline a*, and at
the base of the inclined part is a flange a³. In the acting face of the lump c on the
barrels is a slot c³, and a recess c. In the recess c³ the flange a³ on the rod a takes
when the said rod is in the position, Figure 7.
At the bottom of the acting face of the lump c is an incline ct for acting upon
the incline a on the safety rod a, as herein after explained. On the thumb plate d
at the rear end of the safety rod a is an incline da for the hand lever h, which
works the locking bolt i to act against.
When the gun is ready for discharge, the parts of the safety apparatus occupy
the respective positions represented in Figure 7, the incline a² projecting into the
lump c, and holding the barrels down, and the flange as being situated in the
recess c in the face of the lump c, and the curved stop or arme being removed from
over the sears f
In order to reload the gun after discharge, the hand lever h is turned aside for
unbolting the barrels, the side motion of the said hand lever causing it to bear
against the incline d³ on the thumb plate d of the safety rod a, and move back the
said rod such a distance as will bring the incline a³ into the recess c³, and into
the path of the incline c on the lump c. On the rising of the breech ends of the
barrels the incline con the lump c acts against the incline a² on the rod a, and
forces the said rod back into its safety position, or the position represented in
Figure 8, thereby bringing the stop or arm e over the sears of so as to lock them
down.
Thus the rising of the breech ends of the barrels brings the rod a into its
safety position, and the gun, so long as the rod is in that position, cannot be
discharged.
In order to liberate the sears preparatory to firing the gun, the thumb plate d
on the safety rod a is pressed towards the barrels, thereby removing the stop or
arm e from over the sears, as illustrated in Figure 7.
The same motion of the safety rod a causes its inclined end a to take into the
lump c, and the flange c³ to seat itself upon the shoulder c, thereby locking
down the barrels and forming an underlocking bolt in addition to the ordinary
upper bolt i.
The gun may now be discharged.
Instead of causing the spring g to press directly upon the safety rod a, it may

page_text: In this modification the stem d of the thumb plate & passes through a slot in
the safety rod a, and a spring y, engaging in a recess d³ in the stem d, keeps the
thumb plate to its bearing on the tang of the break off. The stem d' of the thumb
plate slides in the slot in the said tang.
According to another arrangement I modify in the following manner the
ordinary safety apparatus by which a bolt, linked to a spring lever, is brought
over the ends of the triggers and is removed from the triggers by the act of grasping
the gun for firing.
I shape the end of the said bolt so that when it is shot over the triggers it also
engages with the sears.
This part of my Invention is illustrated in Figures 12 and 13, Figure 12
representing the sears and triggers locked down, and Figure 13 the same released,
and the gun ready for firing. a is the lever situated under the trigger guard and
turning on the centre b, and pressed from the said guard by the spring c;
d, d², d³, is the bolt for locking down both the scars and triggers. This bolt works
in the case e, and its rear end is connected by the link f to the front end of the
spring lever a.
The front end of the bolt & has the shape best seen in Figure 12, and when in
its normal position the part d² bears upon the triggers, and the part d³ bears upon
the cross arms of the sears, thereby locking down the said triggers and sears. When
the lever a is grasped in the act of firing the gun, the said lever takes the position
represented in Figure 13, thereby changing the position of the link f, and causing
it to withdraw the front parts d², d³, of the bolt d from over the triggers and
sears, and permitting of the discharge of the gun.
Having now described the nature of my Invention, and the manner in which
the same is to be performed, I wish it to be understood that I claim as my Invention
of improvements in breech loading small arms of the kind called drop down
guns,-
First. The improvements in spring levers for withdrawing the locking bolts of
drop down guns, herein before described and illustrated in Figures 1, 2, and 3 of
the accompanying Drawings, that is to say, constructing the said levers with a
recess or box in which the spring is stationed and works, the free end of the spring
taking a bearing against a stud or projection on the upper face of the tang of the
break off substantially as described and illustrated, whereby the making of a slot
in the tang and the cutting-away of a portion of the stock is rendered
unnecessary.
Secondly. The improvements in the fore end fasteners of drop down guns
herein before described and illustrated in Figures 4, 5, and 6 of the accompanying
Drawings, that is to say, a fastener consisting essentially of one or two springs
marked p, p, p, carried by the bar of the fore end and a sliding rod or releaser
marked q, q, the locking stud or studs on the spring or springs engaging in a hole
or holes in the loop to fasten the fore end, and being withdrawn from the said
loop to release the fore end by the sliding rod or releaser, as described and
illustrated.
Thirdly. The improvements in safety apparatus for preventing the accidental
discharge of drop down guns, herein before described and illustrated in Figures 7,
8, 9, 10, and 11 of the accompanying Drawings, that is to say, giving the back
motion to the sliding rod of the safety apparatus so as to cause its stop or arm to
lock the triggers by the action of the lump on the barrels when the breech ends of
the barrels are raised to open the gun, the several parts being constructed and
operating substantially as described and illustrated.
Also causing the fore end of the sliding rod of the safety apparatus to take into
the lump on the barrels when the said rod is moved forward to release the triggers,
and the means described and represented for withdrawing the safety rod from the
lump on the unbolting of the barrels.
Lastly. The improvements in safety apparatus, herein before described and.
illustrated with respect to Figures 12 and 13 of the accompanying Drawings, that

page_text: is to say, modifying the front end of the bolt of the safety apparatus in the manner
described and illustrated, for the purpose of causing it in its shot position to lock
both the triggers and scars.
In witness whereof, I, the said John Field Swinburn, have hereunto set my
hand and seal, this Fourteenth day of April, in the year of our Lord One
thousand eight hundred and eighty-one.
Witness,
RICHARD SKERRETT.
37, Temple Street,
Birmingham.
JOHN FIELD SWINBURN. (L.S.)