AN IMPROVEMENT IN THE ACTION OF BREAK-DOWN GUNS WITH A SNAP FASTENING
Year: 1870

page_text: LETTERS PATENT to James Purdey, of Oxford Street, in the County
of Middlesex, Gun Maker, for the Invention of "AN IMPROVEMENT IN
"
Sealed the 11th April 1871, and dated the 28th November 1870.
PROVISIONAL SPECIFICATION left by the said James Purdey at the
Office of the Commissioners of Patents, with his Petition, on the
28th November 1870.
I, JAMES PURDEY, of Oxford Street, in the County of Middlesex,
Gun Maker, do hereby declare the nature of the said Invention for
"AN IMPROVEMENT IN THE ACTION OF BREAK-DOWN GUNS WITH A SNAP FASTENING,"
to be as follows :—
This Invention relates to break-down guns which are provided with a
snap bolt for securing the barrels in position after loading the same at
the breech, and it consists in locking the triggers during the back.
movement of the bolt, and thereby providing against the possibility of
an-accident from firing before the barrels are brought home.

page_text: In adapting the Invention to guns in which the snap bolt is worked
by a lever under or over the trigger guard, I fit the back spring (through
which the triggers work) with a cross bar in advance of the triggers, and
I cut a vertical notch or recess in the triggers to receive the cross bar.
As the snap bolt is forced back by the act of bringing the barrels into
position the back spring (which gives the snap bolt a forward tendency)
will through its lever be depressed, and its cross bar will thereby bo
brought into the recess of the triggers. Thus the triggers will be
effectually locked, and will remain so until released by the rise of the
back spring consequent on the advance of the snap bolt to its locking
position.
When applying the Invention to guns which have a lever at top for
working the snap bolt I fit the lower end of the spindle to which the
lever is attached with a crank pin, which pin is intended to enter a
notch in a locking bar which lies upon, and is free to move over the
inner face of the trigger. plate. This locking bar is formed with a head
or cross piece, which enters the notches or recesses of the triggers; and
the thickness of this cross piece is so proportioned with respect to the
slot or recess as to allow the triggers to move when the locking bar is in
its quiescent position. When, however, the snap bolt is held back the
crank pin of the lever spindle will cause the locking bar to lock the
triggers, as before explained, and thus secure the piece against being
prematurely discharged or before the barrels have been brought home
and secured.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Purdey in the Great Seal Patent Office on
the 27th May 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
PURDEY, of Oxford Street, in the County of Middlesex, Gun Maker,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of November, in the
year of our Lord One thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors,

page_text: give and grant unto me, the said James Purdey, Her special licence
that I, the said James Purdey, my executors, administrators, and assigns,
or such others as I, the said James Purdey, my executors, adminis-
trators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "AN IMPROVEMENT IN THE
ACTION OF BREAK,DOWN GUNS WITH A SNAP FASTENING," upon the condition
(amongst others) that I, the said James Purdey, my executors or
administrators, by an instrument in writing under my, or their, or one
of their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date
of the said Letters Patent.
NOW KNOW YE; that I, the said James Purdey, do hereby declare
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the Drawing hereunto
annexed, and to the letters and figures marked thereon (that is to.
say):
:-
This Invention relates to break-down guns which are provided with a
snap bolt for securing the barrels in position after loading the same at
the breech, and it consists in a mode of locking the triggers on the
recession of the snap bolt (to bring the dropped barrels into the position
for firing), whereby the gun is prevented from being fired until the
barrels are restored to their normal position and effectually locked.
In the accompanying Drawing I have shewn the Invention as adapted
to a double-barrelled gun in which the snap bolt is worked by a lever
under or in front of the trigger guard.
Fig. 1 represents in longitudinal vertical section the look of the gun
applied to the stock; Fig. 2 is a plan view of the back spring detached;
and Fig. 3 is a detached view shewing the lever for retracting the snap
bolt and for operating the back spring.
A is the gun stock; B, the breech piece; G, the trigger plate; and D;
the trigger box (made fast to the trigger plate), to which the triggers E

page_text: are pivotted; F is the back spring made fast to the trigger plate as
usual, and formed with openings, as shewn at Fig. 2. Through one of
these openings projects the trigger box D, and through the other the
triggers E work. The back spring is formed with a cross bar fin
advance of the triggers, and a vertical notch or recess e is cut in the
triggers (as shown in the detached view of a trigger at Fig. 4) to receive
the cross bar; G is the snap bolt formed in the usual manner to engage
with the "lump" on the barrel, and working in guides in the breech
piece B. This snap bolt is slotted at its rear end to receive the upper
extremity of the lever H, which is pivotted as usual on the trigger plate
and works through a slot formed therein. Jointed to this lever in rear
of its fulcrum is a link h, which carries at its upper extremity a
transverse pin, and this pin rests in a socket formed on the forward
extremity of the back spring F. As the tendency of the spring F is
always to rise, it will, through its connection with the snap bolt, give
that bolt a tendency to advance or retain its locking position. When,
however, the barrels are raised from their dropped to their normal
position the snap bolt will be forced back by the inclined face of the
lump striking against the forward end of the snap bolt, and the back
spring (which gives the snap bolt a forward tendency) will through its
lever be depressed, and its cross barf will thereby be brought into the
recess of the triggers. Thus the triggers will be effectually locked, and
will remain so until released by the rise of the back spring consequent
on the advance of the snap bolt to its locking position. The relative
locking actions of the spring F and snap bolt G are so arranged that the
barf will not release the triggers until the snap bolt has been forced
sufficiently far into the slot or slots of the "lump" as effectually to
secure the barrels in position. Supposing now that from any cause an
obstruction is interposed between the barrels and the breech piece, and
the barrels are thereby prevented from being brought up into line, it ;
will be manifest that the snap bolt will be held back; the effect of this
will be to depress the back spring F, and thereby to maintain the locking
of the triggers.

page_text: effecting the locking of the triggers by the back movement of the snap
bolt in the manner and for the purpose above described.
In witness whereof, I, the said James Purdey, have hereunto set my
hand and seal, the Twenty-sixth day of May, in the year of our
Lord One thousand eight hundred and seventy-one.