IMPROVEMENTS IN PROJECTILES
Year: 1878

page_text: LETTERS PATENT to William Palliser, of No. 21, Earl's Court Square, in the
County of Middlesex, Knight, for the Invention of IMPROVEMENTS IN
PROJECTILES."
PROVISIONAL SPECIFICATION left by the said William Palliser at the
Office of the Commissioners of Patents on the 24th October 1878.
WILLIAM PALLISER, of No. 21, Earl's Court Square, in the County of Middlesex,
Kuight. "IMPROVEMENTS IN PROJECTILES."
My Invention relates to the manufacture of chilled projectiles intended for
penetration of armour plates and other defences in such a manner as to obtain the
hardness necessary for penetration combined with such strength and tenacity as
will admit of the construction of shells containing larger bursting charges than those
of the shells now in use.
For this purpose I construct the shell of two natures of iron, namely, mottled iron
of the kind ordinarily used for the head portion, and iron of a softer and richer
nature, such as that known as No. 5 Pontypool cold blast pig, for forming the body
of the shell For uniting these two qualities of iron to form one shell according to
one method, I proceed as follows:-I provide a chill mould for the whole projectile,
and in this mould I cast the head of the projectile of the hard mottled iron which
becomes chill hardened throughout its substance. Upon this head portion I cast
the body of the softer iron which though cast in a chill mould undergoes chill
hardening only to a limited depth from its surface. If, for instance, the total
thickness of the metal were 2 inches, the chill hardening would with this quality of
iron extend only to about half an inch in depth. Before casting the comparatively
soft body on the hard head I allow the latter to remain in the mould for a short
time, so that while a perfect junction of the two netals is ensured there is no such
amalgamation or mixture of them as would result from the addition of the softer

page_text: By this
metal while the hard metal is quite fluid. Such amalgamation would alter the nature
of the metal, the head part being thereby rendered too soft and the body part too
hard. In order to determine accurately the point of junction of the two metals,
which should be on the cylindrical part of the projectile near the springing of the
curve of the head, it is advantageous to provide through the side of the mould at
the.desired level an overflow hole through which excess of the first poured metal
escapes, the said hole being stopped before pouring the second metal.
arrangement the inetal in the head portion of the mould can by continued pouring
be kept hot and fluid until the second metal is ready to be poured, and thus a
perfect junction can be secured, care being taken to avoid the amalgamation above
-referred-to. Instead of joining the two-qualities of metal by casting the one on the
other as above described, I sometimes make the composite projectile in the following
manner-I cast the head part of the hard mottled iron in a chilled mould, making
its mouth with a projecting hip enclosing-a-ring-of-wrought-iron-or-steel.cast_in_it._
I then separately cast in a chill mould the body of the projectile in the softer metal.
I then cut screw threads in the ring of the head part, and on a projecting lip cast
soft on the body part, and screw the one part to the other, thus forming the
composite projectile with a hard head suited for penetration, and a strong tenacious
body. By this distribution of the two metals I obtain a head having high resisting
power to withstand the pressure resulting from its own momentum as well as that
of the metal behind it, and a body which, while its resistance to crushing is lessened
in accordance with the diminished pressure towards the rear of the projectile, has
its tenacity proportionally increased.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Palliser in the Great Seal Patent Office on the 23rd April
1879.
WILLIAM PALLISER, of No. 21, Earl's Court Square, in the County of Middlesex,
Knight. "IMPROVEMENTS IN PROJECTILES.'
"
My Invention relates to the manufacture of chilled projectiles intended for
penetration of armour plates and other defences in such a manner as to obtain the
hardness necessary for penetration combined with such strength and tenacity as
will admit of the construction of shells containing larger bursting charges than those
of the shells now in use.
For this purpose I construct the shell of two natures of iron, namely, mottled
iron of the kind ordinarily used in the Palliser projectiles for the head portion, and
iron of a softer and richer nature, such for example.as that known as No. 5 Pontypool
cold blast pig, for forming the body of the shell. For uniting these two qualities
of iron to form one shell, according to one method I proceed as follows:-I provide
a chill mould for the whole projectile, and in this mould I cast the head of the
projectile of the hard mottled iron which becomes chill hardened throughout its
substance. Upon this head portion I cast the body of the softer iron, which though
cast in a chill mould undergoes chill hardening only to a limited depth from its
surface. If, for instance, the total thickness of the metal were 2 inches, the chill
hardening would with this quantity of iron extend only to about half an inch in
depth. Before casting the comparatively soft body on the hard head I allow the
latter to remain in the mould for a short time, so that while a perfect junction of
the two metals is ensured, there is no such amalgamation or mixture of them as
would result from the addition of the softer inetal while the hard metal is quite fluid.
Such amalgamation would alter the nature of the metal, the head part being thereby
rendered too soft and the body part too hard. In order to determine accurately the
point of junction of the two metals, which should be on the cylindrical part of the
projectile near the springing of the curve of the head, it is advantageous to provide
through the side of the mould at the desired level an overflow hole through which
excess of the first poured metal escapes, the said hole being stopped before pouring
the second metal. By this arrangement the metal in the head portion of the mould
can by continued pouring be kept hot and fluid until the second metal is ready to
be poured, and thus a perfect junction can be secured, care being taken to avoid the
amalgamation above referred to. Instead of joining the two qualities of metal by
casting the one on the other as above described, I sometimes make the composite
projectile in the following manner :-I cast the head part of the hard mottled iron
in a chill mould, making its mouth with a projecting lip enclosing a ring of wrought
iron or steel cast in it. I then separately cast in a chill mould the body of the
projectile in the softer metal. I then cut screw threads in the ring of the head part
and on a projecting lip cast soft on the body part, and screw the one part to the
other, thus forming the composite projectile with a hard head suited for penetration,
and a strong tenacious body. By this distribution of the two metals I obtain a
head having high resisting power to withstand the pressure resulting from its own
momentum as well as that of the metal behind it, and a body which, while its
resistance to crushing is lessened in accordance with the diminished pressure towards
the rear of the projectile, has its tenacity proportionally increased.
DESCRIPTION OF THE DRAWINGS,
Fio 1 is a vertical section of a chill mould for casting projectiles of two different.

page_text: composite shell made in parts as above described. The head part B is cast of the
hard metal in a chill mould, and there is cast in it a ring C of steel or soft iron in
which is cut an internal screw. The body D of the projectile is cast of the softer
metal with a projecting boss which has an external screw thread cut on it fitting
the thread of the ring C.
Having-thus described the nature of my Invention and in what manner the same
is to be performed, I claim,-
First. The construction of cast-iron projectiles having heads chill hardened
throughout their substance, and bodies chill hardened only to a limited depth, sub-
stantially as and for the purposes herein set forth.
Second: The construction of-a-composite projectile consisting of a chill cast head
of hard metal with a steel or soft iron ring cast in it, and of a body of softer metal
having a boss screwed into the said ring, substantially as herein described.
In witness whereof, I, the said William Palliser, have-hereunto-set_my_hand
and seal, this Twenty-second day of April, in the year of our Lord One
thousand eight hundred and seventy-nine.
DITT TORD