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 2nd July 1880.
JOHN FIELD SWINBURN, of Birmingham, in the County of Warwick, Cun
"IMPROVEMENTS IN BREECH LOADING SMALL ARMS."
Manufacturer.
E
My Invention has reference to breech loading small arins of the kind commonly
called drop down guns and pistols, and my said Invention consists of the improve-
ments herein after described in mechanism for effecting the cocking of the gun
by the depression of the muzzle end of the barrels for charging.
To the knuckle of the joint of the fore end I joint an arm, the normal position
of which arm is horizontal, and its length is such that when the barrels are shut
down for firing the gun, the free end of the arm touches or nearly touches the
breasts of the internal hammers in their uncocked position. When the breech
ends of the barrels are raised the angular motion of that part of the joint of
the fore end, to which the arm referred to is jointed, gives to the free end of tho
said arm an advancing motion, that is, a motion towards the breasts of the
Lammers. On the underside of the said arm is an incline, and on the bottom of
the body of the gun is a fixed incline immediately in front of the incline on the
underside of the arm. When the arm commences its advance motion, its incline
comes in contact with the fixed incline, and the advance motion of the arm can
only proceed by the incline on its underside travelling up the fixed incline. The
motion given to the arm is thus compounded of an advance or horizontal motion,
and a vertical motion of its advancing end caused by the action of the two inclines.
The breasts of the hammers are provided with inclined faces on which the
advancing and ascending free end of the arm acts, and throws back the bammers
to the point at which they are retained by the ordinary bent and sears.
the gun has been charged and the barrels shut down for firing the gun, the cocking
arm has been withdrawn to its normal position, and leaves the hammers free to
fall when the triggers are pressed.
When
The fixed incline on the bottom of the body of the gun may be replaced by a
roller, and the free end of the cocking arm may have an anti-friction roller through
which it acts on the inclines on the breasts of the hammers.

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 24th
December 1880.
JOHN FIELD SWINBURN, of Birmingham, in the County of Warwick, Gun
Manufacturer. "IMPROVEMENTS IN BREECH LOADING SMALL ARMS."
My Invention has reference to breech loading small arms of the kind commonly
called drop down guns and pistols, and my said Invention consists of the improve-
ments herein after described in mechanism for effecting the cocking of the gun or
pistol by the depression of the muzzle end of the barrels for charging.
To the knuckle of the joint of the fore end I joint arms, the normal position of
which arms is horizontal, and their length is such that when the barrels are shut
down for firing the gun, the free ends of the arms touch or nearly touch the breasts
of the internal hammers in their uncocked position. When the breech ends of the
barrels are raised, the angular motion of that part of the joint of the foro end, to
which the arms referred to aro jointed, gives to the free ends of the said arms an
advancing motion, that is, a motion towards the breasts of the hammers. On the
underside of each of the said arms is an incline, and on the bottom of the body of
the gun is a fixed incline immediately in front of the incline on the underside of
the arm.
When the arms commence their advance motion their inclines coure in
contact with the fixed inclines, and the advance motion of the arins can only
proceed by the inclines on their undersides travelling up the fixed inclines.
The motion given to the arms is thus compounded of an advance or horizontal
motion and a vertical motion of their advancing ends caused by the action of the two
inclines. The breasts of the hammers are provided with inclined faces on which
the advancing and ascending free ends of the arms act, and throw back the
hammers. to the point at which they are retained by the ordinary bents and sears.
When the gun has been charged and the barrels shut down for firing the gun, the
cocking arms have been withdrawn to their normal position, and leave the haminers
free to fall when the triggers are pressed.
The fixed inclines on the bottom of the body of the gun may be replaced by
rollers, and the free ends of the cocking arins may have anti-friction rollers through
which they act on the inclines on the breasts of the hammers.
I will now proceed to describe with referenco to the accompanying Drawing the
manner in which my Invention may be performed.
Figures 1 and 2 represent in longitudinal section partly in elevation the breech
end of a double barrel drop down gun containing cocking mechanism constructed
according to my Invention, Figure 1 representing the barrels shut down and the
hammers in their discharged position; and Figure 2, the barrels opened for charging
and the hammers cocked; Figure 3 represents in sido clevation, and Figure 4 in
plan, a portion of the fore end of the gun together with the cocking arms jointed to
the knuckle of the said fore end.
The same letters indicate the same parts in all the Figures.
a are the barrels, and 6 the body of the gun. The internal hammers of the gun
aro situated at opposite sides of the body b. One of these hammers is marked c,
and turns on the centre d. These haminers have pointed noses for operating
directly on the cartridges, but flat nosed hammers may be used for acting upon
strikers in the break off. The breasts c³ of the hammers are inclined, and when the
gun has been discharged, the said breasts of the hammers have the position in tho
body represented in Figure 1. The main springs of the hammers are marked e, and
the sears are marked f; 9, 9, are the horizontal arms by which the cocking of the
hammers is effected. The outer end of each cocking arm g is jointed at / to the
knuckle of the fore end bar i, in the manner best seen in Figures 3 and 4, that
is to say, a reduced and pierced part is made at the outer end of the arm g, which
fits in a recess made in the knuckle of the fore end, a joint pin h being passed
through the engaged parts of the arm and knuckle, as represented in Figure 4.
The dotted line indicates the curved fore end of the body b on which the

page_text: knuckle 2 of the fore end bar i turus. The joint pins h, h, of the arms g, g, aro
excentric to the curved end is, and hence, when the muzzle ends of the barrels are
depressed, the said joint pins h, k, and arms g, g, are made to advance towards the
butt ond of the gun.
The free ends of the horizontal arms g, g, which bear against the inclined
breasts of the hammers c have curved projections mado upon their upper sides,
and in the underfaces of the said breasts curved recesses are made into which the
said curved projections drop when the hammers are discharged, as represented in
Figure 1. On the underside of each arm g is an incline g³, and on the body of the
gun and immediately under each arm g is a fixed incline k.
When the gun has been discharged the parts occupy the respective positions
represented in Figure 1, that is, the jointed arms g, g, are horizontal, the inclines
gg, on the said arins being situated at the bottoms of the fixed inclines on the
body. When the breech ends of the barrels a aro raised from the break off for
charging the gun, the angular motion of the knuckle part of the fore end to
which the arins g, g, are jointed gives to the free ends of the said arms an
advancing motion, or a motion towards the breasts c of the hammers. As the
said arins advanco, their inclines in contact with the fixed inclines on the
body travel up the said fixed inclines into the position represented in Figure 2,
thus giving to the said arins an advance or horizontal motion and a vertical
motion. As the arins g, g, make the compound motion described, their free ends
act upon the inclined faces of the breasts c of the hammers, throwing the said
hammers into the position at which they are retained by the scars engaging
with the bents in the said hammers, as represented in Figure 2, where one of the
hammers is reprosented thrown back and held in its cocked position. On shutting
down the barrels a after charging them, the jointed arms 9, 9, return to the
horizontal position represented in Figure 1, leaving the hammers c in their cocked
position ready to discharge the gun.
Instead of the fixed inclines on the bottom of the body b rollers may be used,
and the free end of each horizontal cocking arm g may be provided with an
anti-friction roller through which it acts on the inclined breast of the hammer.
Having now described the nature of my Invention, and the manner in which tho
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 commonly called drop
down guns and pistols,―
The construction and combination of parts herein before described and illustrated
in the accompanying Drawing, for cocking the internal hammers of the said guns
and pistols by the depression of the muzzle ends of the barrels for charging, that is
to say, the combination of the horizontal cocking arins g, g, having incliues on their
undersides jointed excentrically to the knuckle of the joint of the fore end, with
fixed inclines or rollers on the body of the gun or pistol, whereby on the raising of
the breech ends of the barrels for charging them, a compound motion consisting of
an advance horizontal motion and a vertical motion is given to the free ends of the
cocking arms, and the said free ends of the arms made to cock the hammers,
substantially as described and illustrated.
In witness whereof, I, the said John Field Swinburn, have hereunto set my
hand and seal, this Twenty-third day of December, in the year of our
Witness,
RICHARD SKERRETT,
37, Temple Street,
Birmingham.
JOHN FIELD SWINBURN. (L.S.)