Year: 1887

page_text: Date of Application, 22nd Mar., 1337
Complete Left, 21st Dec., 1887
Complete Accepted. 17th Feb.. 1838
HIRAM STEVENS MAXIM, of 57" Hatton Garden, in County of Middlesex,
Mechanical Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to the manufacture of steel guns and is designed to provide
for increasing the strength of the same, and the homogeneity of the metal of which
they are composed.
Steel guns have, in some instances, been manufactured from solid castings or ingots
by forging the same to the required external shape and roughly boring them, and then
tempering or toughening the same by heating them in a furnace and, when heated to
the required temperature, plunging them into oil.
An important feature of my present invention consists in twisting the steel casting
or ingot while hot and before forging the same to the required shape and boring it.
I thus ensure that the grain or fibre of the metal shall extend in the direction
calculated to give the greatest strength to the gun, that is to say, that the grain or
fibre shall extend circumferentially or spirally around the bore. And I am in this
manner enabled to put any desired number of units of work" into the steel, and
can therefore produce guns of very great strength. Moreover the twisting of the
casting or ingot ensures uniformity in the distribution of the carbon and increases
the homogeneity of the metal.
Another important feature of my said invention consists in re-heating the gun,
after the tempering or toughening of the same has been effected in the ordinary
manner, and then, while the gun is still in the furnace, cooling the same from the
interior by means of air, water, oil or other suitable cooling medium, so as to
impart to the
gun a molecular condition such as that which exists in a built-up gun.
In making a gun according to my present invention, I prefer to proceed as follows,
that is to say I take a steel casting or ingot of the requisite dimensions and twist
the same while hot by means of a lathe or other suitable machine, until the desired
number of units of work" has been put into the steel. I then forge the said casting
or ingot to the required shape and roughly bore the same and temper or toughen it
D

page_text: by means of oil in the ordinary manner, the cooling being effected from the outside
as well as from the inside of the gun. I then heat the gun to a red heat, and while
it is still in the furnace, I cool it from the interior, using for this purpose a blast or
current of cold air, or of air and steam, or of air having in suspension therein water
in a finely divided or atomized condition; or a blast or current of air combined with
a spray of oil or a stream of oil or of hot or cold water; the means employed being
varied according to the nature or hardness of the steel, the dimensions of the gun and
other circumstances.
In some instances, I repeat the operation of tempering or toughening in the
ordinary manner and that of cooling from the interior twice or oftener for the purpose
of improving the quality of the steel.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements relating to the Manufacture of Guns.
I, HIRAM STEVENS MAXIM, of 57" Hatton Garden, in the County of Middlesex,
Mechanical Engineer do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement:-
My invention relates to the manufacture of steel guns and is designed to provide
for increasing the strength thereof and the homogeneity of the metal.
Steel guns have, in some instances, been manufactured from solid castings or ingots
by forging the same to the required external shape and roughly boring them, and
then tempering or toughening the same by heating them in a furnace and, when
heated to the required temperature, plunging them in oil, and then finishing them.
53
In the manufacture of a gun in this manner, it is usual to hammer or otherwise
work the steel to a greater or less extent in order to ensure the desired toughness and
density thereof. According to the amount of hammering or other working to which
the steel is subjected for this purpose, a larger or smaller number of " units of work
is said to be put on to the forging or into the steel for instance, if the ingot is
hammered or otherwise worked until its length has been doubled or its sectional area
otherwise reduced by one-half, one "unit of work" is said to have been put into the
metal if the sectional area of the ingot is again reduced by one-half, two units of
work are said to have been put into the metal, and so on.
Heretofore the requisite number of units of work has been put into the steel by
hammering or drawing the casting or ingot. This hammering or drawing is dis-
advantageous, as will hereinafter appear. Moreover, in the process heretofore
adopted of toughening or hardening the gun, the metal is liable to warp and crack.
An important object of my said invention is to provide for putting any desired
number of units of work" into the metal of the casting or ingot from which a gun
is to be made, without the necessity for hammering or drawing the ingot for this
purpose. I accomplish this result by twisting the steel casting or ingot preferably
while hot and before the same is forged to the required shape and bored. Inthis
manner, moreover, I ensure that the grain or fibre of the metal shall extend in the
direction calculated to give the greatest strength to the gun, that is to say, circum-
ferentially or spirally around the hore. I can thus produce guns of very great
sirength as compared with those in which the requisite number of units of work is
put into the steel by hammering or drawing. Moreover the twisting of the casting
or ingot ensures uniformity in the distribution of the carbon and increases the
homogeneity of the metal.
Another object of my said invention is to provide for imparting to the gun a
molecular condition similar to that which exists in a built-up gun. For this purpose
I first temper or toughen the gun in the ordinary manner and then reheat the same
and, while it is still in the furnace, I cool it from the interior by means of air, water,
oil or other suitable cooling medium.

page_text: =
In making a gun according to my present invention, I proceed as follows, that is
to say I take a steel casting or ingot of the requisite dimensions, and twist the
same while hot by means of a lathe or other suitable machine, until the desired number
of units of work has been put into the steel. I then forge the casting or ingot
thus lengthened, to the required shape or configuration and roughly bore the same
and temper or toughen it by means of oil in the ordinary manner, the cooling being
effected from the outside as well as from the inside of the gun. I then heat the gun
to a red heat, and, while it is still in the furnace, I cool it from the interior using for
this purpose a blast or current of cold air, or of air and steam, or of air having in
suspension therein water in a finely divided or atomized condition; or a blast or
current of air combined with a spray of oil; or a stream of oil or of hot or cold
water; the means employed being varied according to the nature or hardness of the
steel, the dimensions of the gun and other circuinstances. I then finish the in
gun
any convenient manner.
In some instances, I repeat as often as may be required, the operation of tempering
or toughening in the ordinary manner, and that of cooling from the interior while
subjected to heat externally as above described, for the purpose of improving the
quality of the steel.
It is evident that, by twisting the ingot, instead of hammering or drawing the
same, to put the desired number of units of work into the metal, the effect of any
air-hole or flaw in the metal will be diminished instead of increased. For instance,
assuming a flaw, such as a spot containing too much or too little carbon, to exist in
the ingot, the effect of hammering or drawing the ingot would be to lengthen the
said flaw and draw it out lengthwise of the gun, whereas, by the twisting, it is drawn
out circumferentially or spirally.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I wish it understood
that I claim :-
First. The method of working a casting or ingot from which a gun is to be made,
consisting in twisting the said casting or ingot substantially as hereinbefore
described.
Second. The manufacture of a gun from a steel casting or ingot by twisting the
said casting or ingot until the required number of units of work has been put into
the metal and then forging and finishing it, substantially as hereinhefore described.
Third. The method of hardening or tempering a gun, consisting in first heating
the same and cooling it by means of oil in a well-known manner, and then reheating
it and cooling it from the interior while its exterior is subjected to heat and, if
desired, repeating these operations, substantially as hereinbefore described.
Fourth. The manufacture of a gun from a steel casting or ingot, by twisting the
said casting or ingot until the required number of units of work has been put into
the metal, then forging the said casting or ingot to the desired shape or configuration
and roughly boring the same, then tempering or toughening it in the ordinary
manner, reheating it and cooling it internally while its exterior is subjected to heat,
and, if desired, repeating these operations of tempering or hardening, and then
finishing the gun, all substantially as hereinbefore described.
Dated this 20th day of December 1887.
Dated this 20th day of December 1887.
HIRAM STEVENS MAXIM.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.