Improvements in Shaping Ductile Metals to Form Concave, Indented, or Hollow Articles.
Year: 1887

page_text: WESE
Date of Application, 17th Dec., 1887
Complete Specification Left, 15th Sept., 1888
Complete Specification Accepted, 19th Oct., 1888
PROVISIONAL SPECIFICATION.
Improvements in Shaping Ductile Metals to Form Concave, Indented,
or Hollow Articles.
We JoHN KIRKWOOD, and JAMES KIRKWOOD, of 236 Leith Walk, Leith, in the
County of Mid Lothian, North Britain, Bath Manufacturers, and DANIEL WILLIAM
KEMP, of Ivy Lodge, Trinity, Edinburgh, in the same County, Metal Merchant, do
hereby declare the nature of this Invention to be as follows, that is to say :-
This Invention has for its object the shaping of ductile metals in an improved,
novel, and comparatively inexpensive manner; and it is applicable for producing a
great variety of articles, such as baths, bath canopies, basins, dishes, dish covers,
evaporating pans, boilers, float balls, cisterns, sinks or jaw boxes, boxes, cans, and
the like, including articles heretofore made by lathe-spinning processes, or by
means of presses and dies, or by hammering.
=2
The Invention consists in employing fluid pressure and heat in combination with
suitable moulds, the pressure being applied in a manner to act on a sheet or plate
of the ductile metal and force it gradually and steadily into the concave or hollow
part of a mould shaped internally to fit the external shape intended to be given to the
ductile metal. Thus, for example, if a sheet of zinc is to be shaped into a basin or
into a dome, a castiron mould is made consisting of two parts one of which is of a
basin-like form and has a flat flange round its edge whilst the other is a cover of a
flat or nearly flat form and has a flange which can be bolted or otherwise tightly
fastened to the flange of the basin-like part. The zinc sheet is fixed between the
two parts of the mould and steam or other fluid under pressure is admitted between
the zinc sheet and the cover of the mould and produces the desired effect.
pressure of the steam should not be more than what will act with comparative slowness
as too great a pressure will rupture the metal. Thus a pressure of between 20 and
30 pounds per square inch has been founds uitable for operating on sheet zinc, and the
heat which steam of that pressure possesses has been found sufficient.
The

page_text: In some cases a mould will not be required but merely a ring to fix the sheet of
ductile metal to a cover between which and the sheet the fluid pressure is admitted.
With ductile metal of good and uniform quality the fluid pressure will impart a
spheroidal or similar form without a mould surface: and when operating in this
way heat may be applied directly to the outside of the sheet that is being operated on.
The pressure and heat required will vary with the kind of ductile metal operated
on, and with the thickness. In some cases heated and compressed air may be
used, or any suitable gas or vapor, or a heated liquid; and if found desirable in
any cases heat may be applied to the exterior of the mould either in addition to
or instead of heat being applied to the pressing fluid prior to such fluid being
introduced into the mould.
Amongst the ductile metals to which the Invention is believed to be applicable
may be mentioned lead, tin, zinc, copper, silver, gold, malleable iron, and mild steel,
to which may be added alloys of two or more of these metals.
Dated this Sixteenth day of December 1887.
EDMUND HUNT,
Applicants' Agent.

page_text: Improvements in Shaping Ductile Metals to Form Concave, Indented,
or Hollow Articles.
We, JOHN KIRKWOOD, and JAMES KIRKWOOD, of 236 Leith Walk, Leith, in the
County of Mid Lothian, North Britain, Bath Manufacturers, and DANIEL WILLIAM
KEMP, of Ivy Lodge, Trinity, Edinburgh, in the same County, Metal Merchant, 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, that is to say:-
This Invention has for its object the shaping of ductile metals in an improved, novel,
and comparatively inexpensive manner; and it is applicable for producing a great variety
of articles, such as baths, bath canopies, basins, dishes, dish covers, evaporating pans,
boilers, float balls, cisterns, sinks, or jaw boxes, boxes, cans, or the like, including
articles heretofore made by "lathe-spinning" processes, or by means of presses or
dies, or by hammering.
The Invention consists in employing fluid pressure and heat in combination with
suitable moulds, the pressure being applied in a manner to act on a sheet or plate of
the ductile metal and force it gradually and steadily into the concave or hollow part
of a mould shaped internally to fit the external shape intended to be given to the
ductile metal.
A sheet of explanatory drawings is hereunto appended to be hereinafter referred to
in particularly describing the manner of practically carrying out the Invention in the
case of some of the various articles for the shaping of which the Invention is applic-
able. The figures on the sheet of drawings are all vertical sections excepting
figures, 4, 7, and 10, which are plans; and in all the figures the same reference
letters are used to mark the same or like parts wherever they are repeated.
If a sheet of zinc is to be shaped into a basin, or into a dome a castiron mould such
as is shown in figure, 1, is made, consisting of two parts, A, B, one of which, A, is of
a basin-like form and has a flat flange, C, round its edge, whilst the other, B, is of a
nearly flat form and has a flange, D, which can be bolted or otherwise tightly fastened
to the flange, C, of the basin-like part, A. The zinc sheet, shown by a thick black
line, being indicated in its original flat form partly by a dotted line, is fixed in the
mould between the flanges, C, D, and steam or other fluid under pressure is admitted
by a pipe, E, so as to enter between the zinc sheet and the bottom cover, B, of the
mould and produces the desired effect. A pipe, F, is provided for blowing off water
of condensation. The pressure of the steam should not be more than what will act
with comparative slowness as too great a pressure will rupture the metal.
pressure of between 20 and 30 pounds per square inch has been found suitable for
operating on sheet zinc not exceeding 1 inch in thickness, and the heat which steam
of that pressure possesses has been found sufficient for zinc of the thickness mentioned.
The pressure and heat required will however vary in different cases according to the
kind and thickness of the ductile metal which is being operated on and also according
to the area of metal subjected to the pressure. Thus for example if a dome or
Thus a

page_text: basin of 30 inches in diameter is to be made of zinc which is inch in thickness
steam of about 160 pounds per square inch and corresponding temperature should be
employed.
In shaping a dome or hemisphere such as is shown in figure, 1, the metal is apt to be
drawn thinner at and near the middle of the top than near the parts held by the
flanges, C, D. With the view of having the thickness of the ductile metal more
nearly uniform it may be first subjected to a modified mould shaped so as to draw or
thin out to some extent those parts which are less drawn in the final operation. A
mould top, G, such as is shown in figure, 2, is used for the partial preliminary drawing
operation, this piece being formed with annular corrugations at and near the outer
parts whilst the middle part is flat. On the pressure being admitted the middle part
of the zinc or other ductile sheet is pressed and held against the flat part of the mould
top, G, whilst it is stretched at the outer parts so as to fill the corrugations in the
mould top, G. The corrugated mould top, G, is then removed and a dome-shaped
mould top (A) fixed onl
as indicated by dotted lines, and the steam pressure,
which should be shut off during the change is again admitted and the shaping
completed..
In some cases a mould top will not be required, but, as shown in figure, 3, merely a
ring, H, to fix the sheet of luctile metal to a dish shaped casting, B, between which
and the sheet the fluid pressure is applied. With ductile metal of good quality the
fluid pressure will impart a spheroidal or similar form without a mould surface; and
when operating in this way heat may be applied directly to the outside of the sheet
that is being operated on.
In some cases heated and compressed air may be used, or any suitable gas or
vapor, or a heated liquid; and if found desirable in any cases heat may be applied to
the exterior of the mould either in addition to or instead of heat being applied to the
pressing fluid prior to such fluid being introduced into the mould or shaping apparatus.
The apparatus may, in some cases, be made as shown in figure, 3, without pipe con-
nections for steam or fluid, a little water or other liquid being put in the bottom
vessel, B, before fixing on the zinc or other ductile slicet. On heat being applied
below the vessel, B, by means for example of a Bunsen gas burner sufficient pressure
will be generated within the vessel to cause the shaping of the ductile metal into the
desired form without using a separate steam boiler.
Figures, 4, to 11, are diagrams on a reduced scale showing some of the forms which
may be shaped according to this Invention. Irregular forms may also be produced,
and the inner surface of the mould top, A, may be shaped to form an ornamental
surface on the ductile metal operated on. Two or more sheets of ductile metal may
be operated on simultaneously. In some cases the metal may be annealed between
successive stages of the shaping operation but such annealing will not generally be
required.
Among the ductile metals to which the Invention is believed to be applicable may
be mentioned lead, tin, zinc, copper, aluminium, silver, gold, malleable iron, and mild
steel, to which may be added alloys of two or more of these metals.
Having now particularly described and ascertained the nature of our said Inven-
tion and in what manner the same is to be performed, we declare that what we
claim is
The shaping of ductile metals to form concave, indented, or hollow articles by
applying fluid pressure and heat and by means of apparatus substantially such as is
herein before described.
Dated this Thirteenth day of September 1888.
EDMUND HUNT,
Applicants Agent.