CERTAIN IMPROVE-: MENTS IN THE CONSTRUCTION OF THE LOCKS USED FOR THE DISCHARGE OF GUNS AND OTHER FIRE-ARMS UPON THE DETONATING PRINCIPLE
Year: 1823

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I,,
JOHN JACKSON, of the Town of Nottinghani, Gun Maker, send,
greeting.
WHEREAS I did, by petition, humbly represent to His present;
Majesty King George the Fourth, that I had invented "CERTAIN IMPROVE-:
MENTS IN THE CONSTRUCTION OF THE LOCKS USED FOR THE DISCHARGE OF GUNS
AND OTHER FIRE-ARMS UPON THE DETONATING PRINCIPLE;" His Majesty :
was pleased to issue His Letters Patent under the Great Seal of Great
Britain, bearing date at Westminster, the Twenty-ninth day of July, in,
the fourth year of His reign; which Letters Patent do give and grant;
unto me, the said John Jackson, and to my exors, adññors, and assigns,
or to my and their deputies, servants, or agents, His said Majesty's 'espe-
cial licence to make, use, exercise, and vend my said Invention within i
England, Wales, and the Town of Berwick-upon-Tweed, and to have and
enjoy the whole profit, benefit, and advantage arising by reason of the :
said Invention, during the term of fourteen years from the date of the.
said Letters Patents; by which His Majesty also requires and strictly.
commands all His subjects whatsoever within England, Wales, and the';
Town of Berwick-upon-Tweed, that during the continuance of the said:
term of fourteen years they shall not, either directly or indirectly,

page_text: make, use, or put in practice my said Invention, or any part of it, or in
anywise counterfeit, imitate, or resemble the same; the said Letters
Patent also contain a proviso, obliging me, the said John Jackson, to
particularly describe and ascertain the nature of my said Invention,
and in what manner the same is to be performed, by an instrument in
writing under my
hand and seal, and to cause the same to be inrolled
in His Majesty's High Court of Chancery within two calendar months
after the date of the said Letters Patent.
NOW KNOW YE, that in compliance with the said proviso, I, the
said John Jackson, have executed this instrument, by which I do hereby
declare that the nature of my said Invention, and the manner in which
the same is to be performed, are particularly described and ascertained
in and by the Drawing hereunto annexed, and the following description
thereof (that is to say):
Figure 1, represents part of a double gun with the left-hand lock
taken off, and the other cocked; Figure 2, the same, with the cock let
down; and Figure 3, the lock taken off the gun. In all these Figures.
as well as in all the others, the same letters of reference indicate similar
parts. A, the lock plate; B, the cock. In all these Figures the
magazine to hold the detonating priming powder is indicated by the
.dotted lines at C; and in Figure 4, the same is shewn in section.
D,.
in Figures 4, 5, and 6, the tumbler; E, the lever of the tumbler, fitting
upon the square F, shewn in Figure 6, and secured from coming off by
the screwed nut G, Figures 9 and 10, and which also keeps the
tumbler in in its place in the cock; H, a spring catch affixed to the.
lever E, the use of which will be described hereafter; I, a perforated
cap, which screws upon the top of the magazine, and has a cork fitted.
into it to keep the priming from falling out of the magazine in use, but.
which gives way in case the priming should happen to take fire, and
allows it to escape without doing any injury; J, a friction roller mounted
in a stud affixed to the lock plate, and the use of which will be described
hereafter; this is shewn separately in Figure 11. It will be seen that
the magazine for the priming C, is curved at its lower part, and meets
the tumbler D, on the side opposite to the orifice J, in the cock, which
is made to receive the nipple L, affixed in the breech of the gun barrel,

page_text: cap or
and that the tumbler D has a cavity M in it, shewn in section in
Figure, and by dotted lines in Figures 1, 2, 3, and 5. In Figures 3
and 5, this cavity M is shewn as being brought, by turning the lever.
E, by hand, opposite to the opening into the magazine C, to receive its
priming, the gun being at the same time held with its muzzles down-
wards; the gun is then to be raised, and the lever E. depressed by
turning it until the spring catch H at the back of it falls into a
notch N, shewn in Figures 2 and 3, made in the side of the cock B to
receive it, and where it remains in the position shewn at M, in Figure 1,
until on the trigger being pulled the cock falls, and the lever E, striking
against the friction roller J, is brought into the position shewn in
Figure 2, and the cavity M, with the priming in it, comes into contact
with the top of the nipple L, when the priming fires by the percussion,
and discharges the gun. The left lock, Figures 14 and 15, exhibits:
another method of actuating the tumbler D, it being thereby rendered
self-acting. This is effected by connecting the lever E of the tumbler:
with lock plate A, by means of the swivel rod or bar 0 (which may
either be made straight or crooked). In this case the magazine C is
made quite straight, and meets the tumbler D, at the upper part of it,
instead of on one side, as in the lock before described. Here the'
tumbler D receives and delivers the priming by the acts of cocking and
discharging the lock. The dotted lines in Figure 15, shew the lock as
cocked, and the tumbler in the act of receiving the priming powder
from the magazine; and the cock is also shewn in the same Figure in
its discharged state, with the cavity in the tumbler opposite to the hole
K, in the cock which receives the nipple. Figure 14, shews the lock
when at half cock. Figure 16, is a section of the magazine in the
cock. Figure 17, the lever E, with a hole in the end of it to receive
the screw or pin which unites it with the swivel rod O, and which rod
is shewn separately in Figure 18.
I do not mean or intend hereby to claim as my Inventions the
magazines and tumblers in the cocks of the locks, such being already
in use; but I do hereby claim as my Inventions the manner of retaining
the tumbler by the spring catch H, as above described, so as to prevent
the priming powder from falling out of the cavity in it, and the method

page_text: of giving the ultimate inovement to it, by the lever E coming into
contact with the friction roller J, on the lock being discharged, and
also the method of rendering the tumbler self-acting, as described.
In witness whereof, I, the said John Jackson, have hereunto set
my hand and seal, this Twenty-sixth day September, in the
year of our Lord One thousand eight hundred and twenty-