IMPROVEMENTS IN DROP DOWN 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 DROP DOWN SMALL ARMS " to be as follows:-
:-
My invention has reference to the top locking lever mechanism and the safety
mechanism of drop down small arms and consists of the several improvements
herein after described whereby the said top locking lever and safety mechanisms
are made very efficient.
I will describe my improvements applied to a double gun. The top locking lever
is jointed to the tang of the break off and the short broad arm or tongue which
engages with the slot in the prolonged rib between the barrels works under a
bridge in the break off. For the purpose of automatically holding the top lever
out of action after the gun has been opened and for liberating the said lever on
shutting down the barrels I use a horizontal spring detent or catch situated at the
left hand side of and under the bridge in the break off. On the side of the short
arm or tongue of the top lever is a tooth for the spring detent or catch to engage
with. When the top locking lever has been turned aside sufficiently far to with-
draw its tongue from the prolonged rib so as to unlock the barrels the spring detent
or catch snaps onto the tooth described on the said tongue and thereby holds the
top lever in its unlocking position in which position it is retained until the barrels
are shut down. On shutting down the barrels a part of the side of the prolonged
rib strikes against and presses inward the spring detent which is thereby liberated
from the tooth on the tongue part of the top lever and on the barrels reaching
their fully closed position the now released top lever by the action of its spring
takes its normal position and locks down the barrels.
In order to force the barrels more firmly against the break off and to hold them
in position more securely than is effected by the ordinary arrangement of the top
locking lever I modify the bearing parts of the said top lever in the following
manner Instead of making the seat or bearing under the bridge on which the
tongue part of the lever seats itself horizontal or flat as usual I make the said seat
or bearing slightly inclined downwards from the left hand side to the right hand
or joint side of the top lever so that on the tongue part of the lever seating itself
upon the said inclined seat it slightly descends or moves from a horizontal line and
thereby exerts a wedging or screw like action upon the inclined bearing of the
[Price 61

page_text: prolonged rib on which it takes the effect of which wedging or screw like action is
to hold the barrels very firmly in their place.
I combine with the safety slide of the double gun the following mechanism for
locking the triggers and for locking one of the sears when the other sear is lifted
by its trigger. The safety slide referred to in its back position passes over the ends
of the sears and prevents them rising and in its forward position permits of the
lifting of the sears. To the top of the said safety slide I joint a lever capable of
oscillating through a small angle in a horizontal plane. The front of the said
oscillating lever is enlarged so as to form side wings and on the underside is a
small block operating in front of the safety slide the wings being so arranged as to
partly cover one of the sears on the pulling of the triggers. A double or forked
spring fixed to the slide and bearing against a stud at the front end of the
oscillating lever gives the back or return motion to the said lever. The safety
slide having been taken out of action and the gun made ready for discharge the
pulling of one of the triggers say the right hand trigger causes an incline on its
inner side to operate upon the block of the oscillating lever. The said lever is
thereby turned aside and one of its wing parts is made to cross the sear of the left
hand trigger which is thus locked down and prevented from rising. On pulling
the left hand trigger the right hand sear is locked by the oscillating lever in a
similar way.
On loosing the trigger one or other branch of the double spring
returns the oscillating lever to its normal position in which position it does not
overhang either of the sears. But by slightly moving the top locking lever the
block of the oscillating lever locks the triggers in which locked position they
remain until the gun is again made ready for firing.
Although I have only described my invention in connection with a double barrel
drop down gun my said invention is also applicable to single barrel drop down
guns.

page_text: 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 DROP DOWN 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 the top locking lever mechanism and the safety
mechanism of drop down small arms and consists of the several improvements
hereinafter described, whereby the said top locking lever and safety mechanisms are
made very efficient.
I will describe my improvements applied to a double gun.
On
The top locking lever is jointed to the tang of the break off and the short broad
arm or tongue which engages with the slot in the prolonged rib between the
barrels works under a bridge in the break off. For the purpose of automatically
holding the top lever out of action after the gun has been opened and for liberating
the said lever on shutting down the barrels I use a horizontal spring detent or
catch situated at the left hand side of and under the bridge in the break off.
the side of the short arm or tongue of the top lever is a tooth for the spring detent
or catch to engage with. When the top locking lever has been turned aside
sufficiently far to withdraw its tongue from the prolonged rib so as to unlock the
barrels the spring detent or catch snaps onto the tooth described on the said
tongue and thereby holds the top lever in its unlocking position in which position
it is retained until the barrels are shut down. On shutting down the barrels a part
of the side of the prolonged rib strikes against and presses inwards the spring
detent which is thereby liberated from the tooth on the tongue part of the top
lever and on the barrels reaching their closed position the now released top lever by
the action of its spring takes its normal position and locks down the barrels.
In order to force the barrels more firmly against the break off and to hold them
in position more securely than is effected by the ordinary arrangement of the top
locking lever, I modify the bearing parts of the said top lever in the following
manner. Instead of making the seat or bearing under the bridge on which the
tongue part of the lever seats itself horizontal or flat as usual I make the said seat
or bearing slightly inclined downwards from the left hand side to the right hand
or joint side of the top lever so that on the tongue part of the lever seating itself
upon the said inclined seat it slightly descends or moves from a horizontal line and
thereby exerts a wedging or screw like action upon the inclined bearing of the
prolonged rib on which it takes, the effect of which wedging or screw like action is
to hold the barrels more firmly in their place than by the ordinary method.
I combine with the safety slide the following mechanism for locking the triggers
and for locking one of the sears when the other sear is lifted by its trigger. The
safety slide referred to in its back position passes over the ends of the sears and
prevents them rising and in its forward position permits of the lifting of the sears.
To the top of the said safety slide I joint a lever capable of oscillating through a
small angle in a horizontal plane. The front of the said oscillating lever is enlarged
so as to form side wings and on the underside is a small block operating in front

page_text: of the safety slide the wings being so arranged as to partly cover one of the sears
on the pulling of the triggers. A double or forked spring fixed to the slide and
bearing against a stud at the front end of the oscillating lever gives the back or
return motion to the said lever. The safety slide having been taken out of action
and the gun made ready for discharge the pulling of one of the triggers, say the
right hand trigger, causes an incline on its inner side to operate upon the block of
the oscillating lever. The said lever is thereby turned aside and one of its wing
parts is made to cross the sear of the left hand trigger which is thus locked down
and prevented from rising. On pulling the left hand trigger the right hand sear is
locked by the oscillating lever in a similar way. On loosing the trigger one or
other branch of the double spring returns the oscillating lever to its normal position
in which position it does not overhang either of the sears.
But by slightly moving the top locking lever the block of the oscillating lever
locks the triggers in which locked position they remain until the gun is again made
ready for firing.
Figures 1 and 2 represent in plan and Figures 3 and 4 in plan, partly in
horizontal section, a portion of a double barrel drop down gun provided with my
arrangement for automatically holding the top locking lever out of action after the
gun has been opened, Figures 1 and 3 representing the barrels closed and the top lever
in its normal or locking position and Figures 2 and 4 representing the barrels open
and the top lever held out of action.
a is the top locking lever turning on the centre band provided with the spring c
situated in the box or hollow of the lever for giving the said lever the snapping
action when released; a² is the short arm or tongue of the locking lever working
under the bridge d in the break off; e is the prolonged rib on the end of the barrels
into the slot or recess f in which rib the short arm or tongue a² of the locking
lever takes for locking down the barrels; g is the horizontal spring detent or catch
situated in the bridge in the break off and h is the tooth on the side of the tongue
or short arm a² of the top lever for the spring detent g to engage with. When
the barrels are locked down the locking parts and the detent occupy the positions
represented in Figures 1 and 3. On turning aside the top locking lever a for
unlocking the barrels as illustrated in Figures 2 and 4, the spring detent or catch g
snaps onto or engages with the tooth h and thereby holds the top lever a in its
unlocking position in which position it is retained until the barrels are shut down.
On shutting down the barrels the side of the prolonged rib e strikes against and
presses inwards the long arm of the detent g thereby liberating it from the tooth h
on the tongue a³ of the top lever and on the barrels reaching their fully closed
position the now released top lever a by the action of its spring c takes the position
represented in Figures 1 and 3 and locks down the barrels. Thus the top locking
lever is automatically held out of action on opening the gun and released on closing
the gun.
The construction of the seat or bearing under the bridge d for the tongue a² of
the top lever a to work upon is represented in cross section in Figure 5 where the
said seat or bearing is marked d. It will be seen by an examination of the said
Figure 5 that the seat or bearing d for the tongue a² of the top lever to work
upon is slightly inclined downwards from the left hand side to the right hand or
joint side of the top lever. The result of this arrangement is that when the top
lever is turned into its normal or fastening position for locking down the barrels,
the tongue part a² of the said lever seating itself upon the said inclined scat d²
slightly descends or moves from a horizontal line and thereby exerts a wedging or
screw like action upon the inclined bearing at f in the rib e the effect of which
wedging or screw like action is to force the barrels against the face of the break off
and hold them very firmly in their place.
Figures 6. 7 and 8 represent plans of my improved safety mechanism carried by
the trigger plate of the gun; Figure 9 represents in side elevation partly in
longitudinal section the mechanism by which the oscillating lever on the safety
slide is made to lock both the triggers: Figure 10 represents in plan the safety

page_text: mechanism drawn to a larger scale; Figure 11 represents the same without the
oscillating lever and its spring; Figure 12 represents & cross section of the
oscillating lever sears and trigger blades; Figure 13 represents the safety slide
detached and Figure 14 the oscillating lever and its spring detached; i is the
safety slide the tail end of which works in a slot in the trigger plate k. When
the safety slide i is in the back position Figure 6 it is brought over the turned in
ends, of the sears 1, 2 and locks them and when the said slide is in the forward
position represented in Figures 7. 8 and 11 the said slide is withdrawn from over.
the ends of the sears and the latter can be lifted for discharging the gun; m is
the oscillating lever the tail end of which is jointed to the slide i at m². The said
oscillating lever m moves through a small angle in a horizontal plane as represented
and indicated in Figure 8; p is the double or forked spring of the oscillating lever
the said spring being fixed at m² to the slide i. The branches of the spring p bear
against a stud n at the front of the oscillating lever m for giving the back or
return motion to the said lever and the free ends of the said spring bear against
the stud wor the trigger plate when the oscillating lever is in its forward position;
m³, m² are the side wings at the front of the oscillating lever for locking one or
other of the Bears 7, and q is a small block on the underside of the oscillating
lever. The block 9 is operated upon by an incline r on the inner side (see
Figure 12) of the triggers 8 when either trigger is pulled as hereinafter explained.
On the tang is a slide t carrying the depending or vertical arm u the bottom end
of which takes into a recess in the safety slide i. By moving the tang slide t
forward the safety slide i and the oscillating lever m are inoved into the positions
shown in Figures 7 and 8 and the safety slide is out of action, that is, it is clear
of the ends 12, 12 of the sears and the gun may be discharged. On pulling, say,
the right hand trigger its incline acting against the block q of the oscillating
lever m turns aside the said lover into the position represented in Figure 8 and
one of its wings m² is made to cross the sear of the left hand trigger and the last
named sear is locked. On pulling the left hand trigger the oscillating lever mis
moved in the opposite direction on its centro and the other wing m³ of the
oscillating lever m is made to cross the sear of the right hand trigger as indicated
in dotted lines in Figure 8. By means of the branches of the spring p the
oscillating lever is returned to its normal position Figures 7 and 10 in which
position its wings do not overhang either of the sears L, L.
In order to lock both the triggers, the top locking lever a is slightly moved
aside. By this motion it operates upon the inclined end of the tang slide t (see
Figures 1, 2, 3 and 4) and pushes the said slide backwards and through the arm u
draws back the oscillating lever. The block g of the oscillating lever m being no
longer over the inclines », on the triggers but over the square or flat parts of the
triggers the said triggers cannot rise and hence both the said triggers are locked
in which locked position they remain until the gun is again made ready for firing
by moving forward the slide t by hand and again bringing the oscillating lever m
into the position represented in Figures 7, 8 and 10.
Instead of jointing the oscillating lever to the safety slide the said lever may be
stationed on the trigger plate as represented in Figure 15 where the oscillating
lever is marked m and the centre on which it turns is marked m². In this
modification the safety slide x for locking the sears is situated at the rear of the
oscillating lever and is worked independently of the oscillating lever.
Although I have only described and represented my invention in connection
with a double barrel gun my said invention is also applicable in part to single
barrel drop down guns.
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 I claim
as my invention of "Improvements in drop down small arms
33
First. The combination of the horizontal spring detent or catch g with the
tooth h on the tongue or short arm a² of the top locking lever for automatically

page_text: holding the said top lever out of action after the small arm has been opened, the
said lever being liberated on shutting down the barrels by the prolonged rib acting
upon the said detent or catch substantially as herein before described and illustrated
in Figures 1, 2, 3 and 4 of the accompanying Drawings.
Secondly. Making the seat or bearing on which the tongue part of the top
locking lever seats itself for locking the barrels, slightly inclined downwards in
the manner and for the purpose herein before described and illustrated in Figure 5
of the accompanying Drawings.
Thirdly. The combination with the safety slide of a double drop down gun or
small arm of the oscillating lever m, m³, q and parts connected with it for locking
both the triggers and for locking one of the sears when the other sear is lifted by
its trigger as herein before described and illustrated in the accompanying Drawings
whether the oscillating lever be carried by the safety slide or be stationed on the
trigger plate.
Dated 11th don
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