IMPROVEMENTS IN LOCKS FOR FIRE-ARMS
Year: 1864

page_text: PROVISIONAL SPECIFICATION left by John Parker Lindsay at the Office
of the Commissioners of Patents, with his Petition, on the 12th August
1864.
I, JOHN PARKER LINDSAY, of the City and County of Newhaven, State of
Connecticut, United States of America, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN LOCKS FOR FIRE-ARMS," to be as
follows:-
The object of my Invention is to combine two hammers so as to be
operated by one trigger, and so that but one hammer can be discharged by a
single pull upon the trigger; and my Invention consists in the use of a detent,
which is operated by one of the hammers, so as to arrest the trigger after it
has discharged the first hammer, and prevent its action on the sere of the second
hammer to discharge it (the second hammer) until the trigger has been released
after discharging the first hammer, which discharge and release releases the
trigger from the action of the detent, when by again pulling the trigger the
second sere will be operated upon, so as to discharge the second hammer.
This Invention will be better understood by referring to the accompanying
Sheet of Drawings, in which Fig. 1 is a side view of a complete lock; Fig. 2
the same, with side of frame removed and both hammers set at full cock;
Fig. 3, same as Fig. 2, the right-hand hammer discharged; Fig. 4, a top
view; and Fig. 5, a partial front end view.
A is the frame of the lock, in which the hammers B and C and their
operative mechanism are placed; B is the right-hand hammer; C, the left-

page_text: hand hammer hung on a pivot at d, see Figs. 4 and 5, with mainspring 8. a, b,
are the seres, see Fig. 5, hung upon a fulcrum f; care sere springs to force
the seres into the notches of the tumblers D; E is the trigger hung between
the two seres upon the same fulcrum f; the rear end of the right-hand sere a
is longer than the left-hand sere b, so that the trigger will come in contact
first with the right-hand sere; I is a detent hung upon a fulcrum i, its rear
end pressed up by a spring n; the rear end of the detent is forced down
from the position in blue to that in black, Fig. 3, by the act of cocking the
right-hand hammer A, and is held in the position in black also, see Fig. 2,
by the said right-hand hammer A, the left-hand hammer having no effect
whatever upon the detent. Both hammers being cocked, as in Fig. 2, draw
the trigger to discharge the first hammer (the right hand) A, and a notch c
on the trigger will strike the detent, as in black, Fig. 3, the hammer A is
discharged, but the detent is held down by the trigger and prevents the
trigger from being drawn back any further, which it must be before it can
discharge the other hammer B, therefore releases the trigger and allows it to
be forced forward by the pressure of the detent upon it to its original position
in Figs. 1 and 2, and in red, Fig. 8; the detent will be released from the
action of the trigger and will fly up, as denoted in blue, Fig. 3; now it is
out of the way of the trigger, which may be again pulled back, and this time
far enough to act upon the sere 6 and discharge the second hammer B, thus
but one charge can be ignited at one time. I have represented the right-
hand hammer as being first discharged; this is not essential, as the arrange-
ment may be reversed, and the left-hand hammer first discharged; or either
one of the hammers may be used singly, the other being down.