Improvements in Tools for Forging Steel Shells and for other Hollow Forgings.
Year: 1891

page_text: Date of Application, 6th Mar., 1891
Complete Specification Left, 2nd Jan., 1892-Accepted, 6th Feb., 1892
PROVISIONAL SPECIFICATION.
Improvements in Tools for Forging Steel Shells and for other
Hollow Forgings.
I, GEORGE HOOкHAм, of Nos. 7 & 8 New Bartholomew Street Birmingham,
Manufacturer do hereby declare the nature of this invention to be as follows
When it is attempted to raise a hollow from a solid cylinder in red-hot iron or
steel by placing the solid cylinder in a close-fitting die, & driving a punch into it,
a great, or even the greater, part of the work performed by the punch is done
against friction between the metal & the sides of the die. The object of my
invention is to relieve the punch which forms the hollow in the previously solid
metal from this work due to friction. I may, for instance, use a die open at both
ends & place the punch, (which is generally of smaller diameter than the die)
pointing upwards, just beneath it. The solid cylinder or blank is placed, red-hot,
in the die-a plunger, fitting the die, descends upon it, & drives it through the die,
so that the blank impinges upon the punch (which is preferably pointed or ogival-
headed) & is forced along & around it. An objection to this method is that
the hot metal softens the punch-and the method I prefer is the following: A
plunger is placed below the hollow die, and forms the bottom of the die. This
plunger, as soon as a stamp or hammer begins to work the punch rises upwards
through the die.
At starting the upper surface of the plunger is at such a height that when the
blank is placed in the die & rests upon the plunger, the upper surface of the said
blank is about level with the top of the die or protrudes above it. The plunger is
forced upwards either by hydraulic pressure, or by gearing which may or may not
be connected with the mechanism that actuates the stamp or hammer. As the
plunger rises it carries with it the blank, and overcomes the friction of the blank
against the sides of the die. Instead of using a die, cylindrical throughout, and
allowing the blank, at starting to stand, above the die, I prefer to make the die
bell-mouthed at its upper end, so that the emerging metal is partially confined by
the sloping sides of the mouth of the die. I sometimes adopt special means to
prevent the punch from picking up the metal. I may prepare the blank by forging
it with a pointed end which finally forms the point of the shell, & I may finish it,
by rolling, swaging or drawing processes. The hollow cylinder formed in accordance
with my invention is useful also as the first process in solid tube drawing & for
other hollow forgings. I do not confine myself to iron or steel as the metal
operated upon.
Besides relieving the punch from performing the work against friction, as above
described, if the punch is conical at the end, & the conical part does not wholly
enter the die, the metal can expand as it leaves the die, & is not necessarily
cylindrical (externally) after the operation is performed, but becomes enlarged in
diameter as regards that portion of it which has been raised above the die. This
further relieves the work upon the punch.
Dated this 5th day of March 1891.

page_text: COMPLETE SPECIFICATION.
Improvements in Tools for Forging Steel Shells and for other
Hollow Forgings.
I GEORGE HOOKHAM of Nos. 7 and 8 New Bartholomew Street Birmingham
Manufacturer, do hereby declare the nature of my 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 consists of the improvements hereinafter described in tools for
forging steel shells, such as quick firing shells, and for forging other hollow
forgings.
When it is attempted to raise a hollow from a solid cylinder in red hot iron or
steel by placing the solid cylinder in a close fitting die and driving a punch into it,
a great or even the greater part of the work performed by the punch is done
against friction between the metal and the sides of the die.
The object of my invention is to relieve the punch which forms the hollow in the
previously solid metal from this work due to friction.
I may, for instance, use a die open at both ends and place the punch (which is
generally of smaller diameter than the die) pointing upwards just beneath it. The
solid cylinder or blank is placed red hot in the die; a plunger fitting the die
descends upon the blank and drives it through the die so that the blank impinges
upon the punch (which is preferably pointed or ogival headed) and is forced along
and around it. An objection to this method is that the hot metal has a tendency
to soften the punch; and the method I prefer is the following. A plunger is
placed below the hollow die and forms the bottom of the die. This plunger as
soon as a stamp or hammer begins to work the punch, rises upwards through the
die. At starting the upper surface of the plunger is at such a height that when
the blank is placed in the die and rests upon the plunger, the upper surface of the
said blank is about level with the top of the die or protrudes above it. The
plunger is forced upwards either by hydraulic pressure or by gearing which may
or may not be connected with the mechanism that actuates the stamp or hammer.
As the plunger rises it carries with it the blank and overcomes the friction of the
blank against the sides of the die.
Instead of using a die cylindrical throughout and allowing the blank at starting
to stand above the die, I prefer to make the die bell mouthed at its upper end so
that the emerging metal is only partially confined by the sloping sides of the mouth
of the die.
I sometimes adopt special means to prevent the punch from picking up the
metal.
I may prepare the blank by forging it with a pointed end which finally forms
the point of the shell and I may finish the tubular blank or partly made shell by
rolling swaging or drawing processes.
The hollow cylinder formed in accordance with my invention is useful also as the
first
process in solid tube drawing and for other hollow forgings.
I do not confine myself to the use of iron or steel as the metal operated upon.
Besides relieving the punch from performing the work against friction as before
described, if the punch is conical at the end and the conical part does not wholly
enter the die, the metal can expand as it leaves the die and is not necessarily
cylindrical externally after the operation is performed, but becomes enlarged in
diameter as regards that portion of it which has been raised above the die. This
further relieves the work upon the punch.
I will now describe with reference to the accompanying drawing the arrange-
ment of the tools which I prefer to employ in carrying my invention into effect.
Figures 1 and 2 represent vertical sections (partly in elevation) of tools
constructed according to my invention to be used in forging a quick firing steel

page_text: shell, that is to say, for effecting the punching operation upon a cylindrical blank
from which a quick firing steel shell is afterwards to be made, Figure 1 representing
the tools after the steel blank has been put in the cylindrical die and before the
punch has operated upon the said blank and Figure 2 representing the said tools
after the forging or punching operation has been performed upon the blank and the
partly made shell lifted from the die.
Figure 3 represents an elevation of the eccentric and slide arrangement for
working the plunger or lifter, taken in a plane at right angles to that in which the
elevations of Figures 1 and 2 are taken; and Figure 4 represents a double blank
of the kind which I prefer to use in practising my invention for the manufacture of
steel shells.
The same letters of reference indicate the same parts in the several figures of
the drawing.
a is the fixed die in which the blank is punched or made hollow. This dic may
either have a cylindrical figure throughout or it may be slightly bell mouthed at its
upper end as represented in the drawing. Working and fitting closely in the said
die a and having a rising and falling motion given to it in the manner hereinafter
described, is a plunger which closes the bottom of the die a and serves as a lifter
for lifting the partly made shell in the die. The top of the plunger or lifter b has
a hollow conical figure corresponding generally with the pointed end of the shell to
be made, the blank or short cylinder of steel to be operated upon having a pointed
or conical figure at one end to fit in the conical seat or hollow top of the plunger or
lifter b. The steel blank is preferably perforated axially as represented with a
small hole before it is operated upon in the die a (see Figure 1) but a solid
cylindrical steel blank may be operated upon according to my invention to convert
it into a short hollow cylinder or partly made shell. When I use pointed blanks,
two of the blanks may be forged point to point as represented in Figure 4 and
afterwards separated at the pointed junction.
C
The
The plunger or lifter 6 is fixed to the slide c working in the guide d and a rising
and falling motion is communicated to the said slide c by the eccentric on the
shaft g acting through the clip and eccentric rod jointed to the said slide c.
slide c does not commence to lift the plunger or lifter until the eccentric has
ascended through a quarter of a revolution from its lowest point. It consequently
lifts the blank most rapidly when the said blank is hottest and the lifting motion
becomes gradually slower as the blank cools and approaches its highest position ;
is the punch for punching or forging or enlarging the hole in the shell blank the
said punch being fixed to the head k of a rapidly reciprocating hammer or stamp.
To prevent the possibility of the punch lifting the blank from the die a stripper
off such as is commonly used in forging machinery may be employed.
I do not limit myself to the particular mechanism described and represented for
lifting the plunger or raiser in the die a as the said plunger may be lifted by
hydraulic power or by a lever or otherwise.
The operation of the tools is as follows:-
The red hot prepared blank / being placed in the cylindrical or nearly cylindrical
die when the plunger or lifter 6 is in its lowest position, as represented in
Figure 1, and the rapid reciprocating punch being set to work the said punch
penetrates the upper part of the blank enlarging the small axial hole therein and
expanding the hot steel into the bell mouth of the die.
Simultaneously with the action of the punch i the heated blank is lifted in the
die a by the rising motion of the plunger or lifter b, the said blank being first lifted
rapidly for a short distance and afterwards more slowly lifted as hereinbefore
explained. As the partly punched blank is lifted in the die the hole punched
is gradually enlarged and deepened by the punch entering further and further
into the blank until by the time the punched or tubular blank has reached
the position Figure 2 the required depth and enlargement of hole has been
punched or forged in it, and the motion of the punch being arrested the
tubular blank or partly made shell can be lifted by the workman from the die and

page_text: the plunger or lifter 6 having descended to its lowest position another red hot blank
is placed in the die and the operations hereinbefore described are repeated. As
the blank is being lifted in the die during the operation of the punch the friction
between the said blank and the sides of the die is mainly confined to the zone in
which the punch is acting, the portion of the blank above the said zone being
relieved of friction by the expanded mouth of the die, the friction of the parts of
the blank below the said zone being borne by the lifter; the friction is thereby
reduced to a minimum especially if the die is made slightly taper from top to
bottom.
During the punching operation that part of the blank which is external to and
consequently not confined by the die a is slightly enlarged or expanded. The
partly made quick firing shells thus made may be finished by ordinary rolling,
swaging or drawing processes. Or the short hollow cylinder forged by the use of the
tools constituting my invention may be employed in the manufacture of solid drawn
tubes and used for other purposes where hollow forgings are required.
In the accompanying drawing I have represented the tools and appliances as
arranged according to the second described arrangement; that is, the arrangement
in which the blank ascends during the operation of the tools, which said arrange-
ment differs from the first described arrangement mainly in the respects that all
the parts are inverted and the punch is stationary. In this arrangement the fixed
punch need not be placed at such a height as to enter the die, its summit being at
or below the level of the lower face of the die. In this case the blank after it has
been operated upon must be quickly stripped from the punch.
Although I have only described the punch as having a reciprocating motion or
being stationary yet I wish it to be understood that the punch may have a steady
advancing or a steady retiring motion.
My invention may be used for forging or punching short solid or hollow cylinders
of copper or Muntz's metal for the manufacture of solid drawn tubes and for other
purposes where hollow forgings are required.
Having now particularly described and ascertained the nature of my inven-
tion and the manner in which the same is to be performed I declare that I claim as
my invention of "Improvements in tools for forging steel shells and for other hollow
forgings
35
A punch having motion or being stationary and a die open at both ends, the said
punch and die being used in combination with a plunger or lifter entering the die
at the side opposite to that at which the punch is situated and advancing the blank
against the punch the said forging tools being arranged and operating in the
manner and for the purpose substantially as hereinhefore described and illustrated
in the accompanying drawing.
1000
W. T. WHITEMAN,
Agent for the Applicant.