Improvements in the Manufacture of Compound. Ingots or Bars for the Use of Jewellers and others and in the Wire Produced from these Bars.
Year: 1888

page_text: Improvements in the Manufacture of Compound. Ingots or Bars
for the Use of Jewellers and others and in the Wire Produced
from these Bars.
I, LEVI LYMAN BURDON, of Broad Street, Providence, Rhode Island, in the United
States of America, Mechanic, do hereby declare the nature of the said 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 improvements in the manufacture of Compound Ingots,
the ingots thus made being adapted to be reduced or drawn down to produce seamless
plated wire.
Heretofore in the production of gold-plated wire, that is wire used by jewellers in
making chains, pins, &c., the ingot from which such wire is reduced has been
rectangular in cross-section and composed of a strip of base metal (of suitable
dimensions) to which soldered a thin piece of gold of the desired quality and
covering one face of the base metal strip. The ingot thus made, may be, say, 14 inches
wide, inch thick and 8 inches long. This is now repeatedly passed between
adjustably mounted driven rolls which reduce it to a convenient thickness; this
operation elongates the ingot but at the same time does not materially add to its
width, thereby producing a plated metallic ribbon. Now, in case plated wire is to be
produced the ribbon is cut longitudinally into a series of narrow strips, each being
subsequently "crimped" so as to readily enter the draw-plate, as the end of the strip
emerges therefrom it is seized by suitable pincers which draw the strip through the
plate. The strip is passed through successively smaller openings thereby gradually
bending it from a U-shape form until the two longitudinal edges meet, and thus
producing a comparatively large hollow wire, round in cross-section, and having a
Seam or joint extending throughout its length. It is obvious that the wire must
be subjected to an annealing process several times during its reduction. The wire
is still further drawn out until the desired size is obtained. This small wire will
have the same relative proportion of base-metal to gold that it had in the ingot.
Sometimes the longitudinal seam is soldered, but this operation necessarily increases
the cost of the wire; moreover, the quality of the articles produced from such wire
depends largely upon the care and skill exercised by the workman in concealing, as
far as possible, the longitudinal seam..

page_text: The object of my invention is to produce a superior compound ingot, and
consequently a superior plated wire for jeweller's purposes. To this end my invention
consists of a cylindrical base-metal core portion which is inserted within a seamless
shell or tube of gold or other fine metal, or alloy, leaving a space or chamber at the
top end of the ingot within which solder is placed. (The adjacent surfaces of the
core and tube are previously prepared as common to more readily receive the solder
as it runs down in fusing.) The ingot is now placed within a suitably heated furnace,
the action of the heat serving to fuse the solder and allows it to flow down and
around the said surfaces, thereby uniting the core and shell. After cooling the ingot
is reduced to the size of wire desired by means of suitable rolls and draw-plate. The
annealing operation being repeated as often as necessary.
Wire thus produced from my improved ingot is seamless throughout, therefore the
workman is enabled by its.use to work more rapidly and at the same time produces
more goods in a given time than would be possible by the use of the common plated
or seamed wire. The articles made from my seamless wire are superior in quality
strength and durability.
In the accompanying drawings illustrating my improvements, Figure 1. represents
a perspective view of the compound ingot in partial section, after being soldered and
preparatory to being rolled down to seamless plated wire. Fig. 2. is a sectional
view of the seamless gold tube or shell. Fig. 3. is a similar view of the base-metal
core or central portion of the ingot. Fig. 4. is a vertical central sectional view
showing the core inserted within the tube, and forming a chamber at the top to receive
solder. Fig. 5. is a cross-sectional view of the soldered ingot, taken on line a x of
Fig. 1. Fig. 6. represents sectional views of the compound ingot, the core in this case
being hollow or tubular. Fig. 7. is a view of an unsoldered ingot in partial section,
showing a solder-retaining chamber formed by a removable top piece. Fig. 8. is a
perspective view (in partial section) of a piece of wire reduced from the ingot shown
in Fig. 1. Fig. 9. represents, cross-sectionally, various shapes of seamless wire to
which the ingot may be reduced, and Fig. 10. is a perspective view of a plain finger
ring made from my improved wire.
The following is a more detailed description of my invention:-
A, referring again to the drawings, designates the compound ingot as a whole, the
seamless shell having been soldered to the core, the whole now being ready to be
rolled down or reduced to the desired size, as usual in working metal.
u, indicates the base-metal core or central portion of the ingot, the same may be
made of copper or other metal or composition of metal; the core is turned off true
and smooth, its diameter being substantially the same as the bore of the gold tube
(about to be described) witlin and to which it is to be soldered.
b, designates the gold shell or tube; the same being formed by any suitable process!
which gives to it a practically perfect tubular shape, and having any desired thickness:
and diameter. One way of making such tubes is to take a sheet of gold cut to a
disc-form, after which by the aid of a series of suitably operated plungers it is
gradually shaped to a tube-form, the inner diameter, as just stated, corresponding to
the diameter of the core a. By the use of tubes of this character the shell may be
quite thin, the metal itself being perfectly homogeneous throughout. In cutting off!
the tube, b, I leave it somewhat longer than the core, thereby when the latter is
inserted producing a space or solder-charging chamber, e, at the top, as shown in
Fig. 4.
The object of this chamber is to retain solder. Instead of forming the
chamber by an extension of the tube, the core and shell may be the same length and
an annular cone-shaped piece placed on top to hold the solder, as shown at, c,
Fig. 7.
The adjacent surfaces of the parts, a, and, b, are suitably prepared or covered with
borax, as common in uniting metals by solder; the core is then inserted within the
tube (the whole resting upon a suitable support) loose solder is next placed in the
chamber, c, and the whole then introduced vertically into a suitably heated furnace.
If necessary, the ingot may be revolved during the heating operation. so as to
uniformly expose its entire surface to the heat. The heat acting upon the core and

page_text: shell expands them slightly and at the same time fuses the solder lying within the
chamber, c, and allows it to flow down and around the prepared surfaces of the core
and shell, thereby uniting them together. At the proper time the ingot is withdrawn
from the furnace, when after cooling it is turned off at the ends, as shown in Fig. 1;
the ingot is now ready to be drawn down into seamless plated wire by means of
suitable rolls and draw-plate. During the reducing process the ingot should be
annealed several times.
The operation above described applies equally to the hollow ingot shown in Fig. 6.
By means of this construction, however, the ingot is reduced somewhat easier and
quicker and with a less number of annealings than in the former case.
In practice, I prefer making my improved ingots about 14 inches diameter and
8 inches long.
As hereinbefore stated the ingot may be reduced to wire having any desired shape
in cross-section. The wire produced from my compound ingot will be found to be
soldered and seamless throughout and well adapted to be employed in the manufacture
of chain-links, finger rings, pins and other articles of jewellery. The absence of the
seam gives to the articles made from my improved wire the appearance of solid gold.
It is obvious that a thick or thin tube of gold, as desired, may be soldered to the core,
thereby ensuring a correspondingly relative proportion of gold and base metal in the
wire, upon the reduction of the ingot.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
:-
1. The method or process herein before described of making metallic compound
ingots, the same consisting, first, in inserting the suitably prepared base-metal core
within the seamless tube, and providing a solder-charging chamber at the upper end
of the ingot; next, placing solder within said chamber; then introducing the whole
into a suitably heated furnace or otherwise subjecting the same to a high temperature
which fuses the solder and allows it to flow down and unite the core and tube; and,
lastly, withdrawing the ingot from the furnace, after which it is adapted to be drawn
or reduced to seamless wire of the desired size.
2. The compound ingot hereinbefore described, consisting of a base-metal centre or
core portion and a seamless shell or tube of fine inetal surrounding the sides of said
core and united thereto by solder.
3. The compound wire hereinbefore described, the saine consisting of a base-metal
interior or core and an exterior seamless shell of gold or other fine metal united
to said core by a film of solder, substantially as shown and for the purposes set
forth.
DIAL: 2011
A
11000