Improvements in Apparatus for Forming Sheet Metal Articles.
Year: 1899

page_text: Date of Application, 19th Sept., 1899-Accepted, 17th Mar., 1900
COMPLETE SPECIFICATION.
Improvements in Apparatus for Forming Sheet Metal Articles.
I, WALTER MORRIS BERRY, of 1,124, Monadnock Block, Chicago, Illinois,
United States of America, Mechanic, do hereby declare the nature of this inven-
tion, and in what manner the same is to be performed, to be particularly described
in and by the following statement:
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This invention relates to an improvement in apparatus for contracting sheet
metal articles around hard metal dies.
The invention consists in substantially the construction hereinafter described,
and more particularly pointed out in the claims.
Like letters refer to the same parts in the several figures of the drawing, in
which-
Fig. 1, illustrates a plan view of the machine, with the plunger and uppermost
section removed.
Fig. 2, illustrates a vertical central section of the same.
Fig. 3, illustrates a plan or top view of the complete machine.
Fig. 4, illustrates a central vertical section of the same.
The object of the apparatus is to contract sheet metal articles or shells around
hard metal dies without seams or buckles. The apparatus is especially adapted
to contract gold shells or casings around hard metal cores, such, for instance, as
teeth, watch stems, etc. Gold, as is well known, has great adaptability for expan-
sion, but the converse is not true, for it is very difficult to contract gold by
ordinary methods without seams or buckles, but by the use of this apparatus such
result may be efficiently accomplished.
As a part of this apparatus or machine, there is employed an exterior body or
casing built up of a number of detachable horizontal sections made of hard metal
or other suitable hard material. In the drawing there is illustrated an arrange-
ment which has been found convenient in practice, consisting of an outer body
or casing composed of a lower, an upper, and an intermediate section, which are
respectively designated by the letters A, A & A². These sections may be detach-
ably secured together in any desired manner, but a convenient manner of effecting
this result is well shown in Fig. 4 as consisting in forming a circular recess or
depression in the top of each subjacent section, and a corresponding projection or
shoulder in the bottom of each overlying section. The depressions thus formed
are designated in the drawing, reading from the bottom section, as B, B'; and
the projections, commencing with the bottom one, are designated respectively
as C, C. These projections or shoulders engaging with the depressions prevent-
lateral displacement of the sections, but in addition to this there is provided for
each adjacent pair of sections a tenon and mortise, which provide against relative
rotation of adjacent sections. The tenons are designated by the letter D), and the
mortises by the letter E, in the drawing.
Within these detachable sections of the outer casing or body, there is placed.
the die and its counter-parts. Of course the die varies in shape to conform with
the article desired to be produced, and is made of some hard metal. In the
drawing the die is designated by the letter F, and is shown as surrounded by a

page_text: sheet metal shell, which is designated by the letter G. The counter-part or
counter-die is made up of a number of sections which surround the bottom, sides
and top of the die, and the sheet metal shell which is to be formed thereon. This
counter-die is composed of a soft metal capable of being compressed so as to make
its inner surface conform in shape to the die and press and contract the sheet
metal shell into the shape required around the die. In practice, lead has been
found to be a material well adapted for the purpose, and six sections or pieces
have been found convenient for effecting the best results. An arrangement of
these pieces which has been found advantageous, is shown in the drawing, and
comprises six pieces, viz., a.bottom piece of the counter-die lettered H, four
vertically arranged angular side pieces lettered I, and a top piece lettered K. The
bottom part of the counter-die designated by the letter H, may be conveniently
arranged to rest in, or be held by, a hard metal removing piece L, the body of
which is seated in a counter-sunk recess in the top of the lowermost section of the
outer casing, and which has a stem projecting through such section of the outer
casing and beyond the bottom of the same, as shown in the drawing.
The die, the shell to be contracted or formed, the counter-die composed of the
various parts above mentioned, and the remover, are placed in position as shown
in Fig. 2 of the drawing; then the top piece of the counter-die is placed over
said die and shell, and a plunger M, is placed in position over this top part
of the counter-die, it being supported laterally by the top section A2, of the
outer casing, as shown in Fig. 4 of the drawing. Great pressure is then applied
to the plunger, which results in the counter-die being forced down and causing
the shell of gold, or other material which is desired to be formed, to be con-
tracted around the die in the manner indicated in Fig. of the drawing. The
plunger is then removed and the projecting stem of the remover L, is tapped by
a hammer or some other suitable instrument, and the sections of the counter-die
thereby loosened, when they may be separated and the article which has been
formed may be easily removed.
The hard metal die F, heretofore described, is of course made of any suitable
low-fusing alloy, preferably of an alloy which consists chiefly of cadmium, bis-
muth, tin, and lead, and fuses at the temperature of boiling water, and after the
machine has contracted the article around such die and the article and die have
been removed, the die is melted so as to remove it from the interior of the
article. The fusible alloy must of course be of a character which will melt at a
temperature much lower than that of the article formed, so that it will not alloy
said article. This practice of melting the die from the article is well known, and
forms no part of the present invention.
It is obvious that many modifications may be made in the details of construc-
tion above described, without departing from the principle of the invention.
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:-
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1. In an apparatus for contracting sheet metal, the combination with an
exterior casing composed of sections, of a die, and a counter-die composed of
sections formed of compressible material and arranged in a cavity within the
outer casing and around the die and shell to be formed, and underneath the same,
and a plunger arranged above the die and counter-die and closely fitting the
cavity above the same; substantially as and for the purpose set forth.
2. In an apparatus for contracting sheet metal, the combination with the main
body composed of several sections of hard material detachably secured together,
and provided with a central cavity or chamber, of a die of hard metal, a counter-
die composed of a number of sections of lead surrounding the die and shell to be
formed, both at the sides and underneath the same, and a plunger arranged to fit
the cavity or chamber above the counter-die, and adapted to compress said

page_text: counter-die and shell and thus contract the latter around the die into the desired
shape; substantially as and for the purpose set forth.
3. In an apparatus for contracting sheet metal, the combination with the main
body composed of a number of sections of hard material detachably connected
together, and provided with a central cavity or chamber, of a die of hard metal, a
counter-die composed of several sections of soft metal, arranged underneath and
around the sides of the die and shell to be formed, a plunger adapted to fit the
recess or chamber above the counter-die and die, and a remover. adapted to a
recess below such counter-die and die, and having a projecting stem extending
outside of the main body of the apparatus; substantially as and for the purpose
set forth.
.
00
1000
WALTER MORRIS BERRY.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.