IMPROVEMENTS IN BREECH-LOADING FIRE-ARMS
Year: 1865

page_text: PROVISIONAL SPECIFICATION left by William Henry Aubin at the Office
of the Commissioners of Patents, with his Petition, on the 23rd February
1865.
I, WILLIAM HENRY AUBIN, of Wolverhampton, in the County of Stafford,
Cabinet Locksmith, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN BREECH-LOADING FIRE-ARMS," to be as follows:-
My Invention consists of the mechanical arrangements or combinations of
parts herein-after explained for bolting or fastening down, and releasing the
barrels of breech-loading fire-arms, of the kind commonly called drop down
or snap guns, that is, guns in which the barrels turn in a vertical plane on a
joint at the fore end of the body, the open breech ends being raised from
the false breech or break off for loading, and shut down and firmly held
against the said false breech or break off during discharge. In order to fasten or
lock the barrels I employ a "tumbler bolt" situated in a vertical slot in the break
off. The said "tumbler bolt" is capable of motion in a vertical plane on a
centre. The said "tumbler bolt" is carried by and fitted into a bridle piece
let into the back part of the break off. The said bridle piece consists of a
plate having two projecting parallel blocks upon it, between which blocks
the "tumbler bolt" is situated, and in which it turns. That side of the
tumbler bolt" which is turned towards the barrels has a slot or recess
made in its middle, the said recess dividing the "tumbler bolt" at that side
into two curved tongues. When the barrels are shut down after the
insertion of the cartridges, the bottom of the barrels strikes against the
lower tongue of the "tumbler bolt" causing the said "tumbler bult" to

page_text: turn upon its centre, and its upper tongue to enter a slot situated between
the breech ends of the barrels made for its reception, the lower tongue
receding as the "tumbler bolt" turns on its centre. On raising the barrels
after discharge the bottom of the slot between the barrels strikes against
the upper tongue of the "tumbler bolt" in the said slot, turning it upon its
centre and causes the said upper tongue to enter the recess in the break off
and permits the barrels to be raised. The "tumbler bolt" is maintained in its
locked or fastened position and released by the following mechanism:-Under
the strap or tang of the break off a lever is situated the said lever turning in a
vertical plane. The end of the arm of the lever most distant from the false
breech is provided with a stud or thumb piece which passes through the said
strap or tang to the upper side, and the end of the other arm of the lever is
situated bebind the butt or back of the before described "tumbler bolt."
The last-mentioned arm of the lever is pressed down by a spring. When
the barrels have been shut down, and the upper tongue of the "tumbler
bolt has entered the recess or slot between the barrels, as herein-before
explained, the free end of the lever under the tang, which during the motion
of the "tumbler bolt" has been pressing on the top of the said "tumbler
bolt, engages behind and abuts against the back of the "tumbler bolt" and
supports and maintains it in its locked position, and thereby securely fastens
down the barrels. To release the barrels the stud or thumb plate on the
strap or tang is pressed down. The opposite and free end of the lever to
which the said stud or plate is connected is thereby raised and removed from
behind the locking "tumbler bolt." The "tumbler bolt" being thus un-
supported and free to rotate the barrels are raised by their own weight from
the break off or false breech, the said barrels in their motion turning the
locking "tumbler bolt" on its centre and causing its upper tongue to enter
the recess in the break off or false breech. The barrels having been raised
the upper tongue or locking part of the "tumbler bolt" is situated in the
break off, while the lower tongue protrudes therefrom ready to be acted upon
by the barrels when they are shut down. The "tumbler bolt" is maintained
in the last described or raised position by a spring on the body of the gun
bearing against the under side of the lower tongue of the bolt, the said spring
being sufficiently strong to overcome that which presses down the fixing
lever under the strap or tang.