Improvements in Forging Tubular Metallic Pieces.
Year: 1895

page_text: Date of Application, 10th June, 1895
Complete Specification Left, 10th Mar., 1896-Accepted, 11th Apr., 1896
PROVISIONAL SPECIFICATION.
Improvements in Forging Tubular Metallic Pieces.
I, ALFRED NOBEL of 59 Avenue Malakoff, Paris, in the Republic of France,
Chemist, do hereby declare the nature of this invention to be as follows:-
The object of this invention is to subject tubular pieces of steel, or other
malleable metal intended for guns, hollow shafts, and similar uses, to internal
pressure, for the purpose of moulding the same to shape and tempering the metal.
In carrying out this invention, the pieces to be operated upon, if not cast or
made hollow, are bored through, but in such manner as to make the bore of less
diameter than it should have in the final product. A projectile of hard, but not
brittle steel, of a larger diameter than said bore, shot froin a gun at great velocity,
is directed so as to pass, accurately sighted, through the aforesaid bore, which it
widens by compressing and expanding the metal. Said projectile should be conical
in front, and widening so gradually rearward, as to avoid too violent action, and
the piece to be treated should of course be solidly fixed. Said operation may be
effected either when the aforesaid hollow pieces are heated to redness, or to appro-
priate heat for softening the metal, or at the ordinary temperature, or any
temperature below forging heat at which the metal which is to be operated on is
best suited for aforesaid treatment. If said operation is performed at, say, dull
redness, the metal is generally so soft as to permit of considerable widening of the
bore even with one single shot; but in order to avoid too violent strain, the
operation may be repeated with projectiles of gradually increased diameter. After
sufficiently widening the bore by the aforesaid treatment, while the metal is at,
say, a dull red heat, the hollow metal may conveniently be subjected once or more
to the same treatment at the ordinary temperature. In the latter case, the strain
is much greater than at dull redness, and consequently the diameter of the projectile.
should be little in excess of the diameter of the bore. Since the dimensions of
pieces greatly vary, it must be left to practice to establish for each case the best
manipulation; but to give an idea of the forces which come into play, and the
result to be attained, it may be mentioned, that a gun bore of 57 millimeters
diameter could be widened millimeter by a single shot, the metal being at the
ordinary temperature.
The metal can be subjected to the aforesaid treatment at red heat, or at the
ordinary temperature, or at both temperatures. This operation, made at the
ordinary temperature, serves in a great measure the same purpose as tempering
steel, and greatly enhances the tensile strength of the metal. Pieces of steel, if
tempered and annealed so as to preserve sufficient ductility, can be rendered still
more resisting by being subjected, at the ordinary temperature, to the aforesaid
treatment.
A gun can even be rifled by shooting through its smooth bore a rifled projectile
of proper diameter, so as to form an extended grooved counterpart of the rifling of
the projectile.
The aforesaid operation of widening the bore is conveniently made with
projectiles shot from smooth bore guns at great velocity, but it can also be effected
by projectiles fired from rifled guns.
Dated this 10th day of June 1895.
NEWTON & SON,
Agents for the Applicant.

page_text: BACTA
I ALFRED NOBEL of 59 Avenue Malakoff, Paris in the Republic of France,
Chemist, 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 :-.
The object of this invention is to subject tubular pieces of steel, or other
malleable metal, intended for guns, hollow shafts, and similar uses, to internal
pressure, for the purpose of moulding the same to shape and tempering the metal.
In carrying out this invention, the pieces to be operated upon, if not cast or
made hollow, are bored through, but in such manner as to make the bore of less
diameter than it should have in the final product.
For the purpose of enlarging this bore to the required diameter, a projectile of
hard, but not brittle steel, of a larger diameter than said bore, is provided, which
projectile is shot at great velocity from a gun sighted so as to ensure its proper
passage through the aforesaid bored or hollow piece, which it widens by compressing
and expanding the metal. This projectile should be conical in front, and widening
so gradually rearwards as to avoid too violent action, and the piece to be treated
should of course be solidly fixed. Said operation may be effected either when the
aforesaid hollow pieces are heated to redness, or to appropriate heat for softening
the metal, or at the ordinary temperature, or any temperature below forging heat
at which the metal which is to be operated on is best suited for aforesaid treatment.
If the expanding operation is performed at, say, dull redness, the metal is generally
so soft as to permit of considerable widening of the bore, even with one single shot,
but in order to avoid too violent strain of the metal, the operation may be repeated
with projectiles of gradually increased diameter.
After sufficiently widening the bore by the aforesaid treatment, while the metal
is at, say, a dull-red heat, the hollow metal may conveniently be subjected once or
more to the same treatment, at the ordinary temperature. In the latter case, the
strain is much greater than at dull redness, and consequently the diameter of the
projectile should be little in excess of the diameter of the bore.
Since the dimensions of pieces greatly vary, it must be left to practice to
establish, for each case, the best manipulation, but to give an idea of the forces
which come into play, and the result to be attained, it may be mentioned that a
gun bore of 57 millimeters diameter could be widened millimeter by a single shot,
the metal being at the ordinary temperature.
The metal can be subjected to the aforesaid treatment at red heat, or at the
ordinary temperature, or at the two temperatures in succession. When the metal
is subjected to this operation at the ordinary temperature, the result is equivalent
to that of tempering the steel, and it greatly enhances the tensile strength of the
metal. Pieces of steel, if tempered and annealed so as to preserve sufficient
ductility, can be rendered still more resisting by being subjected at the ordinary
temperature to the aforesaid treatment.
A gun can even be rifled by shooting through its smooth bore a rifled projectile
of proper diameter, which, in its progress through the gun, will form an extended
grooved counterpart of the rifling of the projectile.
The aforesaid operation of widening the bore can be made with projectiles shot
from smooth-bore guns at great velocity, or by projectiles fired from rifled guns.
When forging tubular metallic pieces in the above described manner, the
diameter of each succeeding projectile must of course be somewhat in excess of
that used for the projectile previously fired through the piece, and this would
necessitate the use of a great number of guns, the bores of which should vary
accordingly. In order however to avoid this, and to be able to perform the

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necessary operations with the aid of a relatively small number of guns, a gun with
an appropriate bore is used for the firing of varying diameters of projectiles, but
smaller in diameter than the bore of the gun from which they are to be fired.
This is accomplished by using a sabot or shot bottom of suitable material,-
preferably the lightest which can be used, and of an external diameter fitted for
the bore of the firing gun, while the inner diameter is adapted to fit the projectile.
to be used. When firing such a shot, it will be evident that, as already the
projectile is of somewhat larger diameter than the bore in the piece to be forged,.
the still larger sabot will be prevented from entering said bore, and is thus
completely broken or crushed against the rear end of the piece operated upon.
will be understood that at the firing of the next somewhat larger projectile from
the same gun as before, there will be used another sabot having the same outer
diameter as the prior one, but a somewhat larger inner diameter fitted for the
projectile to be fired.
It.
Having now particularly described and ascertained the nature of the said inven-.
tion and in what manner the same is to be performed, I declare that what I
claim is
The process of forging hollow metallic pieces to the required internal diameter,
at the ordinary or any other temperature suitable for such forging, by driving
through their bore a projectile of somewhat larger diameter thau said bore, or a
series of projectiles of successively larger diameter, substantially as herein set.
forth.
Dated this 5th day of March 1896.
NEWTON & SON,
Agents for the Applicant..