IMPROVEMENTS IN FIRE-ARMS
Year: 1867

page_text: LETTERS PATENT to Clinton Edgcumbe Brooman, of the Firin of Robertson,
Brooman, and Company, of 166, Fleet Street, in the City of London,
Patent Agents, for the Invention of "IMPROVEMENTS IN FIRE-ARMS."--A
communication from abroad by Azel Storrs Lyman, of New York, United
States of America.
PROVISIONAL SPECIFICATION left by the said Clinton Edgcumbe Brooman
at the Office of the Commissioners of Patents, with his Petition, on
the 31st July 1867.
I, CLINTON EDGCUMBE BROOMAN, of the Firm of Robertson, Brooman, and
Company, of 166, Fleet Street, in the City of London, Patent Agents, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN FIRE-
ARMS," to be as follows:-
This Invention mainly consists in the construction of what I term
accelerator guns, that is to say, in addition to the charge of powder supplied
in the ordinary manner to the gun I construct the gun with one, two, or
nore additional charge chambers, the charges of which act upon the projectile

page_text: in succession after the initial charge has been exploded, whereby the motion
of the projectile is accelerated. I do not limit myself to any particular
arrangement or position of these accelerating chambers, but I prefer either of
the two arrangements hereafter described.
c
The first of these arrangements consists in forming in the body of the gun
below and in a line with the bore several, say four, accelerating chambers
which are charged through openings leading from the upper part of the gun;
these openings after the charges have been inserted are closed by screw valves.
The valve stem projects up through the screw, and has a cap nut on its end
to keep out water; it is arranged so that when the screw has made half a turn
in being withdrawn it strikes the cap and lifts the valve from its seat without
revolving it, whereby friction is avoided; a copper cap prevents windage.
When the gun is fired the projectile is driven by the initial charge, which is
comparatively small, past the first accelerator, and the resistance of the shot
causes the fire to set back, down, into, and ignite the powder in this
accelerator; this raises the pressure perhaps half as high as it was raised by
the small initial charge before the inertia of the projectile was overcome.
action of each of the other accelerators is the same.
The
The second arrangement consists in constructing an additional charge
chamber at the breech and outside the bore of the gun. When the initial
charge is fired a wad in front of this charge which closes the communication
between the two charge chambers is forced forward, starts the shot, and allows
the fire to set back and ignite the accelerating charge. This arrangement
applies to muzzle-loaders, and the loading must be effected while the gun is in
a vertical position or nearly so; while loading the powder after filling the
ordinary charge chamber runs over into the accelerating chamber which
surrounds the ordinary chamber. In constructing the breech of guns when
provided with accelerating chambers according to the first described arrange-
ment I have a cap screwing on the outside of the breech as in the Whitworth
gun, but in front of this cap is a taper plug with its stem projecting back
through the cap, and with a nut on its rear end so as to leave about an inch
play in order that when the breech is opened the cap will make half a turn
before it strikes this nut, and lift the plug from its sent without necessarily
revolving it; at the same time friction and the power required to open the
breech are thus greatly lessened.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Clinton Edgcumbe Brooman in the Great Seal Patent Office
on the 31st January 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CLINTON
EDGCUMBE BROOMAN, of the Firm of Robertson, Brooman, and Company, of 166,
Fleet Street, in the City of London, Patent Agents, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirty-first day of July, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Clinton Edgcumbe Brooman, Her special licence that I, the said
Clinton Edgcumbe Brooman, my executors; administrators, and assigns, or such
others as I, the said Clinton Edgcumbe Brooman, 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 King-
dom of Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "IMPROVEMENTS IN FIRE-ARMS," (communicated to me from abroad
by Azel Storrs Lyman, of New York, United States of America,) upon the
condition (amongst others) that I, the said Clinton Edgcumbe Brooman, 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 Clinton Edgcumbe Brooman, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and. ascertained in and by the
following statement thereof, reference being had to the Drawings hereunto
annexed, that is to say :-
This Invention mainly consists in the construction of what I term
accelerator guns,. that is to say, in addition to the charge of powder supplied in
the ordinary manner to the gun I construct the gun with one, two, or more
additional charge chambers, the charges of which act upon the projectile
in succession after the initial charge has been exploded, whereby the motion of
the projectile is accelerated. I do not limit myself to any particular arrange-

page_text: ment or position of these accelerating chambers, but I prefer either of the two
arrangements hereafter described.
The first of these arrangements is represented in Figures 1 to 5 of the
annexed Drawings.
Figure 1 is a top view, and Figure 2 a vertical longitudinal section
of the gun; Figure 3 is a cross section through one of the accelerators or
additional charge chambers; Figure 4 is a rear view, and Figure 5 a front
view.
The arrangement consists in forming in the body of the gun below and in
a line with the bore several, say 4, accelerating chambers A, B, C, D, which
are charged through openings leading from the upper part of the gun; these
openings after the charges have been inserted are closed by screw valves E; the
valve stem projects up through the screw, and has a cap nut F on its end to
keep out water; it is arranged so that when the screw has made half a turn
in being withdrawn it strikes the cap F and lifts the valve from its seat without
revolving it, whereby friction is avoided; a copper cup G prevents windage.
When the gun is fired the projectile is driven by the initial charge at H, which
is comparatively small past the first accelerator A, and the resistance of the shot
causes the fire to set back, down, into, and ignite the powder in this accelerator;
this raises the pressure perhaps half as high as it was raised by the small
initial charge H before the inertia of the projectile was overcome; the action
of each of the other accelerators B, C, D, is the same. The quantity of
powder considered necessary for these accelerator guns for a projectile of say,
280 lbs. is as follows:-For the initial charge H 3 lbs. of mammoth powder;
for the 1st accelerator A, 20 lbs. of mammoth powder; for the 2nd
accelerator B, 20 lbs. of No. 7 powder; for the 3rd accelerator C, 25 lbs. of
cannon powder; and for the 4th accelerator D, 25 lbs. of quick and strong
powder. The accelerator plugs I should be of soft cast steel fitting closely in
and protecting the cast iron from the fire of the powder. In constructing the
breech of guns when provided with accelerating chambers according to this
arrangement I have a cap K screwing on the outside of the breech, as in the
Whitworth gun, but in front of this cap is a taper plug L with its stem
projecting back through the cap and with a nut M on its rear end so as to
leave about an inch play in order that when the breech is opened the cap
K will make half a turn before it strikes this nut M and lift the plug L from
its seat without necessarily revolving it at the same time; friction and the
power required to open the breech are thus greatly lessened. N is the sabot,
which is preferably made of a case of copper or sheet brass, filled with sheets
of pasteboard, and where the back end of the projectile is tapered I use an

page_text: iron plate O in the front of the sabot to prevent the pasteboard being driven
forward around the projectile.
The second arrangement is represented in longitudinal section in Figure 6 and
in cross section in Figure 7. It consists in constructing an additional charge
chamber A at the breech and outside the bore of the gun. When the initial
charge at-B is fired a wad C in front of this charge which closes the commu-
nication between the two charge chambers A and B is forced forward; it starts
the shot, and allows the fire to set back and ignite the accelerating charge A.
This
arrangement applies to muzzle-loaders, and the loading must be effected
while the gun is in a vertical position or nearly so; while loading the, powder
after filling the ordinary charge chamber B runs over into the accelerating
chamber A. The amount of powder in the chamber A should be about 7
times that in the chamber B.
And having now described the nature of the said Invention, and in what
manner the same is to be performed, I declare that I claim as the "Improve-
ments in Fire-arms,"―
First, constructing what I have herein-before called accelerator guns, that
is to say, fire-arms with one or more additional charge chambers, the charges
of which aet upon the projectile after the initial charge has been exploded,
substantially as hercin-before described.
Second, the arrangement substantially as represented in Figures 1 to 5,
and herein-before described, in which accelerating or additional charge chambers
are constructed below the barrel.
Third, the arrangement substantially as represented in Figures 6 and 7,
and herein-before described, in which an accelerating or additional charge
chamber is constructed at the breech around the ordinary charge chamber.
Fourth, the arrangement herein-before described and shown for enabling
the accelerating chambers in the first described arrangement, Figures 1 to 5,
to be charged.
In witness whereof, I, the said Clinton Edgcumbe Brooman, have here-
unto set my hand and seal, this Thirtieth day of January, One thousand
eight hundred and sixty-eight.