IM- PROVEMENTS ON THE ROYAL YORK GUN LOCK, OTHER GUN LOCKS, AND THE LOCKS OF ALL DESCRIPTION OF FIRE-ARMS
Year: 1805

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
GEORGE DODD, of Great Ormond Street, in the County of Middlesex,
Engineer, send greeting.
WHEREAS His most Excellent Majesty King George the Third, did
by His Letters Patent under the Great Seal of His United Kingdom
of Great Britain and Ireland, bearing date at Westminster, the Twenty-
eighth day of February, in the forty-fifth year of His reign, give and
grant unto me, the said George Dodd, my executors, administrators, and
assigns, His especial license, that I, the said George Dodd, my executors,
administrators, and assigns, during the term of years therein mentioned
should and lawfully might make, use, exercise, and vend, within England,
Wales, and the Town of Berwick upon Tweed, my Invention of "IM-
PROVEMENTS ON THE ROYAL YORK GUN LOCK, OTHER GUN LOCKS, AND THE
LOCKS OF ALL DESCRIPTION OF FIRE-ARMS," in which said Letters Patent
there is contained a proviso, obliging me, the said George Dodd, by an
instrument in writing under my hand and scal, to cause a particular
description of the nature of my said Invention, and in what manner the
same is to be performed, to be inrolled in His Majesty's High Court of
Chancery within one calendar month after the date of the said recited

page_text: Letters Patent, as in and by the same (relation being thereunto had),
may more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso in the
said Letters Patent contained, I, the said George Dodd, do hereby
declare that my said Invention is described and ascertained in manner
and form following, that is to say:
The principal objects of my improvements on gun locks are to
render them secure at half cock, to prevent them from catching at
half cock when passing from whole cock to fire the piece, and to
render it difficult or impossible for a false half cock to take place.
The Drawings in the margin of these Presents are instances of
different methods of constructing gun locks to obtain these objects;
viz., Figs 1, and 2, A, centre or axis of the tumbler; B, is whole cock
bent; C, is half cock bent; E, F, D, is the scar, of which D, is the
axis or centre; E, the nose; F, the shank; G, the sear spring; and H,
is the trigger. The bridle is represented by the dotted lines. Fig. 2,
sliews a method of forming the trigger so as to bring it nearer the butt
of the piece, as a matter of optional convenience to those persons who
may wish it. In Fig. 3, the axis on which the sear moves is placed at
the bottom of the lock plate at A, and the shank B, proceeds from any
part above. C, is the axis of the tumbler; D, the sear spring; E, the
trigger; F, the whole cock bent; and G, half cock bent. It is evident
from this construction that whenever the cock is at half cock, as repre-
sented in these Figures 1, 2, and 3, that whatever power is applied to
pull the trigger in the direction used in firing the piece it will tend to
force the sear nose into half cock bent of the tumbler in a ratio pro-
portioned to the power applied, and consequently render tlie lock at
half cock the more secure, as more power is applied to the trigger, an
effect directly contrary to that produced by locks of the ordinary con-
struction, in which it is well known that extra power applied to the
trigger will occasionally discharge the piece. It must be observed that
the principle in constructing my locks is such that, first, that the velocity
of the tumbler shall exceed that of the scar so much. 2, that the
distance between half cock and whole cock bent shall be so great from
the other; and, thirdly, that the distance of the half cock bent, bc, so

page_text: much less from the centre of the tumbler than the distance of the
whole cock bent is from the same centre; or finally, that either two
or the whole of these three cases be so compounded as to prevent the
possibility of the half cock catching when discharged from whole cock.
These instances I conceive sufficient to elucidate the principles of my
Invention, and to shew the impossibility of locks of this construction
going off at half cock, or catching at half cock when fired from whole
cock, or being made to stand at a false half cock. Certain variations
may be made in the situation of the parts, but it must always be kept in
mind that the scar, the tumbler, and the trigger are to be so constructed
that pulling the trigger shall tend to force the sear nose tighter and
firmer into half cock bent or notch, which is effected by giving the
upper part of the trigger a small inclination to the upper part of the
plate.
In witness whereof, I, the said George Dodd, have hereunto set
eight undire
una ve
GEO. DODD. (L.S.)
AND BE IT REMEMBERED, that on the same Twenty-sixth day of
March, in the year above mentioned, the aforesaid George Dodd came
before our Lord the King, in His Chancery, and acknowledged the
Specification aforesaid, and all and every thing therein contained in
form above written. And also the Specification aforesaid was stamped
according to the tenor of the Statute in that case made and provided.
Inrolled the Twenty-seventh day of March, in the year above
written.