A NEW AND IMPROVED METHOD OF RIFLING THE BORES OR CALLIBRE OF CANNON, AND OF MUSQUET, CARBINE, GUN, AND PISTOL BARRELS
Year: 1800

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, 1,
THOMAS GILL, of Birmingham, in the County of Warwick, Gun Maker
and Sword Maker, send greeting.
WHEREAS His most Excellent Majesty King George the Third,
by His Royal Letters Patent under the Great Seal of Great Britain,
bearing date at Westminster, the Second day of August, in the fortieth
year of His reign, did give and grant unto me, Thomas Gill, my
executors, administrators, and assigns, and every of them, by myself
and themselves, or by my and their deputies and deputy, servants or
agents, or such as I, the said Thomas Gill, my executors, administra-
tors, or assigns, should agree with, and no others, from time to time
and at all times hereafter during the term of fourteen years therein
expressed, should and lawfully might make, use, and vend, "within
that part of His Kingdom of Great Britain called England, His
Dominion of Wales, and Town of Berwick-upon-Tweed, my Invention
of "A NEW AND IMPROVED METHOD OF RIFLING THE BORES OR CALLIBRE
OF CANNON, AND OF MUSQUET, CARBINE, GUN, AND PISTOL BARRELS," in
such manner as to me, the said Thomas Gill, my executors, admi-

page_text: nistrators, and assigns, or any of them, should in their discretions
seem meet, and that I, the said Thomas Gill, my executors, admi-
nistrators, and assigns, should and lawfully might have and enjoy the
whole profit, benefit, commodity, and advantage from time to time
coming, growing, and arising by reason of the said Invention, during
the term of years therein mentioned, to have, hold, exercise, and enjoy
the said licence, powers, priviledges, and advantages therein-before
granted or mentioned to be granted unto me, the said Thomas Gill, my
executors, administrators, and assigns, for and during and unto the full
end and term of fourteen years from the date of the said Letters
Patent next and immediately ensuing, and fully to be complete and
ended, according to the Statute in such case made and provided; in
which said Letters Patent there is contained a proviso, obliging me, the
said Thomas Gill, by an instrument in writing under my hand and
seal, to cause a particular description of the nature of my said Inven-
tion, 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
next and immediately after the date of the said Letters Patent, as in
and by the same, reference being thereunto had, will more fully appear.
NOW KNOW YE, that, in compliance with the said proviso, I, the
said Thomas Gill, do declare that my said Invention of "A NEW AND
IMPROVED METHOD OF RIFLING THE BORES OR CALIBRE OF CANNON, AND OF
MUSQUET, CARBINE, GUN, AND PISTOL BARRELS," is performed by means of
a machine made and constructed as in the Drawings hereunto annexed
is described, and herein-after particularly explained (that is to say):
The pendulous lever A, (Fig. VII.) is suspended by an axis at B, and
has a pivot at each end of its axis. This pendulous lever is fixed to
the axle of the water wheel C, by means of the crank lever D, which
passes from the axle of the water wheel to E, an iron pulley turning
upon a stud, which is fixed to the crank lever by a binding screw
behind, and moveable up and down the cleft at pleasure, for riffing
longer or shorter barrels. F, is a sliding frame to which the chains.
are fixed, and which sliding frame moves to and fro upon a fixed
frame marked G. 1, is a bolt screw passing thro' the end of the
above sliding frame F, and a coupling joint with a lever 12, to unite it

page_text: with or separate it from another sliding frame I, (Fig. I.), to prevent
the necessity of stopping the mill at the time the barrels are moved.
K, shews another frame, the feet of which are fixed firm in the ground,
and should be made as permanent and solid as possible; upon this
frame K, the frame I, moves. (These fixed frames K, and G, meet each
other.) In the inner part of the fixed frame K, is a strong iron bar L,
with twenty holes through, capable of receiving the breach ends of as
many gun or pistol barrels as are intended to be rifled at the same
time. This bar should be as strongly bound to the fixed frame as
possible. One of the holes of this bar is described in a letached
Drawing (Fig. 5). The barrel O, here appears as cut through at the
touch hole, where 1, is a plate of steel screwed to and extending
from one end to the other of the bar L. In this steel plate, at
each hole for receiving the breech of the barrel, is a small pin (formed
out of the plate) at 2, which enters into the touch-hole, and assists in
keeping the barrel stealy, whilst the hard wood wedge 3, (Fig. V. VI.)
is driven into the upper part of the hole over the barrel, to hold it suf-
ficiently fast to resist the force of the rifling cutters. At the other end
of the inner part of the fixed franic K, at 5, are twenty groves, for the
barrel muzzles to rest in and to keep them lineal with the rods marked
M (Fig. I. VI) At the cud of the sliding frame I, next the pendulous
lever, is a plate of iron, with twenty fixed female centres 6, which
correspond with the twenty holes in the iron bar L, (Fig. I. XI.) and
receive the centre points of the forcing rods at the other end of the
sliding frame I. At 7, is another plate of iron, with twenty female centres
at the points of screws that move in and out like the screw centre in
the puppet of a common lathe, as the means of putting the rods in and
taking them out. These centres also correspond with those at 6, and
likewise with the holes in the iron bar L, so that the rods and boro of
the barrels are all in one right line, which is necessary, otherwise the
rods would be liable to rub against the sides of the barrel, especially
when at the extremity of cach stroke. The plates are both drawn on
one, and marked N (Fig. XII.) In Fig. VI. a barrel O, is shewn upon
the forcing rods M., also the edges of the plates with centres N, N, the
edge of the iron bar L, and the hard wood wedge. 3. In this Fig. VI.

page_text: is also shewn a pinion of seven teeth upon one of the cutting rods at 4.
The cutters and the forcing rods are join'd by centres. The cutter rod
male, and the forcing rod a female, and join'd in the point marked P
(Fig. VI.) Fig. IX. shews that part of the rod where the cutters are
fixed, which is the full size for a small bore. , and b, are two
cutters of steel b, with a sharp edge for cutting- with speed; and a
with teeth like a file for smoothing any asperities that may happen
from the speedy cutting. These cutters are laid in groves, and two steel
hoops marked c, are driven over them. to keep them in their places.
In Fig. II. is shewn two racks with teeth mark'd R, R. The teeth of
the upper rack are upon the bottom edge, and those of the lower rack
are upon the upper edge. The upper rack is supported at each end
by a pair of rollers of hardened steel, marked S, S. At each end of the
upper rack is a piece of steel screwed, 8; and the edges of these pieces
overhang the thickness of the rack sufficiently for them to have a
strong bearing upon the rollers mark'd S; these steel pieces are also
hardened. Whilst, they bear downwards upon the tops of the rollers,
the thickness of the rack fills the space between the rollers just so as
to have a free motion endways, and acts the same as it would in two
groves or slits.
At the left end of Fig. II. is another roller mark'd U,
of hardened steel, which bears against the edge of an inclined plane
marked T, Fig. VIII.), and which plane is fixed to the permanant or
solid frame K. This inclined plane is to give the twist of the furrows
in the gun barrel, and moves upon a centre screw 9, (which also binds
that end down); at the other end of this plane is a slit, the segment
of a circle, which moves upon and is bound by another screw 10. Upon
the outward limb of this segment is an index pointed to a graduated
segment, the divisions of which give the degree of twist, wanted. When
the plane is fixed, as is here drawn, the machine cuts the rifles straight
down the barrel. Let the index be moved to 15, (Fig. VIII.), it will
cut them to twist one quarter of a turn; move it to 30, the twist will be
half a turn; move it to 45, it will be three quarters of a turn; and to 60,
the rifles will be just once round the barrel. The intermediate divisions
give any degree of twist wanted, to the sixteenth part of a turn. Here it
must be observed that a difference in the length of the barrel makes a dif-

page_text: ference as to the quantity of twist, so that if the barrel to be rifled is shorter
than the length of the plane itself, the index must be set beyond the
divisions, as before mentioned, and by the following rule:-That, let the
length of the barrel be what it may, the rack which bears against. the in-
clined plane must move over such a space as is equal to 13 of its teeth for
of a turn in the twist, 3 of its teeth for half a turn in its twist, 5 of
its teeth for of a turn in the twist, seven of its teeth for a whole turn
in the twist, because seven teeth of the rack carries the pinion of seven
teeth marked 4, (Fig. 1, VI.) one round, which must be done whilst
the sliding frame I, goes a length equal to the length of the barrel to
be raised. Now to explain how these effects are produced, the roller U,
(Fig. 1, II.) is pressed against. the inclined plane T, (Fig. 1, VIII.) by
virtue of a weight which hangs upon a line that comes down from it,
and under a pulley marked W, Fig. 1, II., which is fixed upon the
sliding frame I, in Fig. I, to a loop at 11, which draws the upper
rack forward to bear against the inclined plane, as above, and whilst it
moves forward its teeth act in the pinion of seven teeth marked 4,
which gives the twist to the rifling, and the same to nineteen other
pinions of seven teeth each. When the sliding frame I, which carries
the racks with it, arrives near to the end of its motion, the stud which
is marked 13, (Fig. 1, III.), and which is fixed to the side of the per-
manant or solid frame K, lifts up a lever 14, which lever lifts up a
piece 15, that acts in a groove in the side of the sliding frame I; and
in using the rollers 16, (for there is one on each side of the rack,) lift
up the rack by coming under the steel pieces 8, and throws it out of
contact with the pinions of seven teeth; and as the lower rack is
fastened to the rising piece 15, (Fig. III.) the racks both rise together;
so that while the upper rack is lifting out of contact with the pinions of
seven teeth, the lower rack rises into contact with them. (This is done
to keep the pinions from being shifted whilst the upper rack is out of
them.). This rising is effected at the time when the roller U, Fig. I, II.)
arrives at the foot of a sudden inclined plane marked X, (Fig. I.,
II, VIII), and as the sliding frame I, noves further, the roller U,
rises up the plane X, and throws the upper rack back endways as
much as the dimensions of a tooth. The sliding frame I, still moving
a little further, the roller U, comes upon the part Y, (Fig. VIII.) at

page_text: the top of the inclined plane X; while the roller U, is going up the
plane X, the level or horizontal line at the bottom of the lever 14
(which line is marked 17) is travelling upon the stud 13, to keep
the racks up all that time; and as soon as the roller U, has made its
bearing good upon the part Y, the line 17, is gone all its length
beyond or behind the stud 13. The sliding frame 1, which carries
all the levers and racks with it, is now come to the end of its journey
within a quarter of an inch, and in going that remainder the angle
upon the lever 14, which is between the line 17, and the line 18,
(which line is a sudden inclined plane,) is gone over the stud 13, and
the inclined plane 18, goes slowly down the said stud 13, by which
means the racks come gently down into their places without injuring
the teeth of either rack or pinion. Now the sliding frame T, begins
to return; and as soon as the roller U, is come back again along the
line Y, it is forced by the weight over the pulley W, down the inclined
plane X, and brings the twenty pinions with it, one tooth to the left
hand, different to what they were before the upper rack was lifted out
of them. All the time these changes are taking place the cutters in the
male rod are out of the muzzles of the barrels, as will appear in the
Drawing, Fig. VI. Thus by changing a tooth every stroke or sliding
of the frame I, the seven cutters enter the muzzle again, one division
of seven different to what they came out, and never go again into the
same furrows 'til each cutter has been in every furrow. At the end of
the lever 14, is a bend, which makes the end of it an inclined plane,
and is marked 21; and in Fig. III. the stud 13, has a slope upon it,
marked also 21, so that when the lever 14, is down, the slope of the
stud, as the sliding frame I, returns, comes against the inclined plane of
the said lever marked 14, and occasions the lever 14, to yield sideways
while the end of the stud 13, rubs against it till it has gone by. This
yielding is performed by the centre pin of the lever 14, marked 20,
being rivetted into another short lever in Fig. 1V., marked 19, whose
centre pin is put or fixed perpendicularly into the end of the sliding
frame I, so that the horizontal motion of the lever 19, gives a side
motion to the lever 14, and operates like Dr. Hook's joint, to make
the lever 14, yield to the fixed stud 13; and when the lever 14, is gone
by the stud 13, a spring placed behind the lever 19, forces the lever

page_text: 19, and consequently the lever 14, along with it, into their places again,
and leaves the lever 14, prepared for the next stroke or forward motion
of the sliding frame I. When the lever 14, has recovered its proper
position by means of the spring behind the lever 19), there is a stud 22,
fixed to the sliding frame I, for the lever 19, to bear against, which
always keeps both of them in their proper places. The lifting works
in all its parts herein described are applied at both ends of the rack,
and consequently on each side of the sliding frame I, so that each end
of the rack is lifted alike, for the lower rack is fastened to the piece
inarked 15, (Fig. II. III.,) the same at one end as at the other, and
at the top of each of these pieces 15, is a pair of rollers, alike marked
16; but in the two levers under the pieces marked 15, namely, 14 and
19, there is a reverse; the lever 19, at the right hand end of the rack
points from its centre to the left hand; such a lever 19, at the left hand
of the rack points from its centre to the right hand. The lever 14,
is also reversed, for the inclined plane at the end of it, marked 21,
is the contrary way, because the stud 13, is the contrary way. Lastly,
the two long springs marked Z, (Fig. I. II.) press upon the steel pieces
marked 8, 8, which are screwed upon the upper rack to keep it down
with a sufficient force to overcome any resistance that may happen in
the twenty pinions while they are moving, to give the twist to the
rifling, and these springs are properly tempered to give way to the rise
of the upper rack whilst it is changing its teeth, and that without
injuring their elasticity. The rollers at the ends of the springs are to
take off the friction which otherwise would exist upon the steel pieces
8, 8. Any number of barrels may be rifled at a time by this method
where there is a sufficient maintaining power.
In witness whereof, I, the said Thomas Gill, have hereunto set
my hand and seal, this Twenty-ninth day of August, in the
year of our Lord One thousand and eight hundred.

page_text: AND BE IT REMEMBERED, that on the same Twenty-ninth day
of August, in the year above mentioned, the aforesaid Thomas Gill
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 First day of September, in the year above written.