Improvements in Forging Projectiles and other Hollow Articles.
Year: 1895

page_text: Date of Application, 14th Nov., 1895
Complete Specification Left, 14th Aug., 1896-Accepted, 19th Sept., 1896
PROVISIONAL SPECIFICATION.
Improvements in Forging Projectiles and other Hollow Articles.
'
I, JOSEPH SCHULTE-HEMMIS, Manufacturer, of Düsseldorf, in the German Empire,
do hereby declare the nature of this invention to be as follows:-
This invention relates to the manufacture of hollow articles from malleable material
having an accurately dimensioned inner space cominunicating with the outside through
a narrow passage.
The raw material is first brought into the shape of a long cup or cylindrical
vessel by stamping, pressing, forging, rolling, or similar operations. Into this body is
introduced a core made of easily fusible or destructible material, and having the
Said core
shape of the interior of the hollow article which it is desired to assume.
may be made of one piece or composed of several pieces or parts.
The cylindrical or cup-shaped main body is heated until it becomes malleable, and
is then placed upright in a die or matrix together with the core, which die is
situated under a hammer or in a hydraulic press. Pressure is now applied to the
hollow article longitudinally or transversely, or in both directions, so as to press the
same uniformly on all sides against the core and close it until there remains only a
narrow passage or duct as mentioned above.
In the case of hollow projectiles, which have a conical or conoidal front end, the
bottom of the die is also conoidal, and the pressure is preferably applied by means of
a thick disc acting on the back of the projectile and having the same diameter.
:
For applying pressure both longitudinally and transversely, the piece of work is
laid horizontally in the matrix or lower die, and then compressed by applying the
upper dio, while a third die is caused to press horizontally (and therefore axially)
upon the back of the piece of work. The third die has preferably the shape of a
cylindrical cup fitting into a cylindrical opening formed by the other dies. If there
is no passage left in the wall of the hollow body, a narrow passage is made
artificially.
The piece of work is now heated until the core melts or is destroyed and may be
removed through the said narrow passage.
The fusible core may serve to hold a permanent core composed of several annular
or circular plates enclosing the said fusible core, and secured to the same by any
Buitable means. After the fusible core has been destroyed and removed, the
permanent core remains in the interior of the projectile or other body. The pieces
composing the permanent core may be annular or of any other convenient shape.
The outside or main body of the shell may be made of steel, wrought iron, or
other malleable material. The melting point or the temperature of combustion of
the core should be close to the temperature at which the material composing the
hollow main body can be forged. In the case of steel or wrought iron, this
corresponds to a bright red heat, about 1,000° Centigrade, while for the core a copper
alloy having a fusing point of about 1,050° C. may be used. If the shell be of
copper, which becomes malleable at 500° C. the core may be aluminium, with a fusing
point of 600° C., and the piece of work would have to be heated to about 700°
or 800° C. for releasing the core.
..
In some cases the core may be made of hard wood superficially impregnated with
silicate of soda.
Dated this 14th day of November 1895.

page_text: Improvements in Forging Projectiles and other Hollow Articles.
I, JOSEPH SCHULTE-HEMMIS, Manufacturer, of 12 Parkstrasse, Düsseldorf, in the
German Empire, 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 :-
This invention relates to the manufacture from malleable material of hollow articles
having an accurately dimensioned innor space which communicates with the outside
through a narrow passage.
In the accompanying drawings
Fig. 1 is a vertical section and Fig. 2 a horizontal section illustrating the process of
manufacture of a hollow projectile according to my invention;
Figs. 3 and 5 represent a shell at different stages of its manufacture; Fig. 4
represents the core of the same;
Figs. 6 and 7 represent another process of manufacture; and
Figs. 8 to 13 represent a shell and hollow core at different stages of manufacture.
The raw material is first brought into the shape of a long cup or cylindrical
vessel, a, Fig. 9, by stamping, pressing, forging, rolling, or similar operations. Into
this body a is introduced a core b (Figs. 4 and 5) made of easily fusible or destructible
material, and having the shape which the interior of the hollow article is desired
to assume. Said core may be made of one piece or composed of several pieces
or parts.
The cylindrical or cup shaped main body a is heated until it becomes malleable, and
is then placed upright in a die or matrix, together with the core, which die is situated
under a hammer or in a hydraulic press. Pressure or a series of blows is now
applied to the hollow article longitudinally or transversoly, or in both directions, so
as to press the same uniformly on all sides against the core 6 and to close it until'
there remains ouly a narrow passage or duct as mentioned above.
Fig. 1 illustrates a case in which the blow or pressure is applied to the body
longitudinally, the latter being set into a matrix together with the hollow core b, and
then covered with a disc d. As the matrix or die has the external shape of the
hollow body and is conoidally pointed at the lower end, the material will be compressed
on all sides, so as to fit tightly upon the hollow core.
For applying pressure both longitudinally and transversely, as represented by
Figs. 6 and 7, the piece of work a is laid horizontally in the matrix or lower die o
and then compressed by applying the upper die c² while a third die ³ is caused to
press horizontally (and therefore axially) upon the back of the piece of work. The
third die has preferably the shape of a cylindrical cup fitting into a cylindrical
opening formed by the other dies. If there is no passage left in the wall of the
compressed hollow body a, a narrow passage is made artificially.
The piece of work a is now heated until the core b melts or is destroyed, and may
be removed through the said narrow passage.
As shown by Figs. 10 to 13, the interior of the body a may serve to hold a
permanent core e composed of several plates e enclosing a fusible core b, and secured
to the same by any suitable means. After the fusible core b has been destroyed' and
removed, the permanent core e remains in the interior of the projectile or other body.
The pieces composing the permanent core.e may be annular segments or of any other
convenient shape.
After the closing of the projectile body a and removal of the inner core b, the parts
composing the permanent core e are held together by the former alone, if the said
parts form wedge-shaped segments, as indicated by Fig. 12. The new process is thus
applicable not only for the easy and cheap manufacture from malleable inaterial of
hollow bodies having an accurately dimensioned inner space, but also for providing

page_text: the bollow body a with a hollow core which consists of several parts and has likewise
an inner space of accurately predetermined dimensions.
The main body or shell a may be made of steel, wrought iron, or other malleable
material. The melting point or temperature of combustion of the core should be
close to the temperature at which the material composing the hollow main body can
be forged. In the case of steel or wrought iron, this temperature corresponds to a
bright red heat, and is about 1,000º Centigrade, while for the core a copper alloy
having a fusing point of about 1,050° C. may be used. For releasing the core, the
piece of work would have to be heated to about 1,100° C. at which temperature the
shell will not collapse or melt. If the shell be of copper, which becomes malleable
at 500° C. the core may be aluminium, with a fusing point of 600° C. and the piece
of work would have to be heated to about 700° or 800° C. for releasing the core, at
which temperature the shell itself will not melt, because the melting point of copper
is about 1,500° C.
The core may consist of a material having a melting point far below the temperature
of malleability of the shell. For instance, in the case of steel shells, the core may
consist of lead which melts at 335° C.
In some cases the core may be made of hard wood superficially impregnated with
silicate of soda.
Projectiles having easily fusible cores require much skill and rapidity in their
manufacture, in order that the piece of work may be closed up before the core has
reached the temperature of disintegration.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what I
claim is:
1. The method of forging hollow projectiles and other hollow articles having
accurately determined inner dimensions and a small orifice, which consists in enclosing
in a cylindrical shell a open at one end, by the application of pressure in a heated
condition, a core which has the shape desired for the inner space or hollow of the
said article and which will melt or disintegrate at a lower temperature than the
material of the sholl, and then removing the core by heat, substantially as and for
the purpose described.
2. The method of forging hollow projectiles and other hollow articles having an
accurately dimensioned inner space and a permanent hollow core composed of several
parts, by using an easily fusible or destructible temporary core and a forging press in
the manner substantially as described.
' Dated this 14th dow of A10
FAIRFAX & WETTER,
433, Strand, London, Agents.