Improvements in and relating to the Process of Galvanically Inlaying Metal on Materials.
Year: 1899

page_text: Date of Application, 27th Dec., 1899-Accepted, 3rd Feb., 1900
COMPLETE SPECIFICATION.
Improvements in and relating to the Process of Galvanically Inlaying
Metal on Materials.
I, FERDINAND EPPLER,. of Mauerstrasse 81, Berlin, W., in the Empire of
Germany, Artist and Draughtsman, 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:-
-
The object of the present invention is the inlaying of metal on any desired
material by a galvanic process, for ornamental or other purposes.
The technical improvement which this invention compared with older methods
achieves, lies principally therein, that the metal is not inlaid in the ground
material by a mechanical, but a purely galvanic process.
The method employed hitherto of hammering or pressing the metal in, can of
course, only be employed where the inlaying surface consists of strong and non-
fragile material as that method of inlaying is one which requires laborious and
skilled artistic manual work, which is principally done in the Himalayas, in
Asia, in producing articles of ornament for which thousands of francs are paid,
it is obvious that the articles produced by it are in consequence of their dearness
unobtainable by many persons.
With the present invention the work is done by the electric current, without
any manual labor at all. But in spite of that, the results obtained with this
method are as regards beauty and regularity far superior to those obtainable
by artistic manual labor, and the cost is reduced by this method to a degree
hitherto unknown.
The new method also yields quite new and astonishing results in the effects
of the patterns inlaid.
In the following description the process of the present invention will, with the
aid of the attached drawings be described and explained in various forms of
execution.
Instead of using casts, as in the galvano-plastic precipitation process, it is
necessary with the present method to produce on the surface of the ground
material grooves corresponding to the ornamentation desired or in the shape of
the pattern to be inlaid.
These grooves to be filled afterwards by galvanic means with metal are produced
in the usual way, for instance, by etching the pattern on a layer of acid resisting
material and then biting it into the ground surface by means of an acid.
If the ground surface is suitable the pattern may be engraved upon it at once,
or else a sand blast, which has hitherto not been employed for such purposes,
may be used. The latter, as compared with engraving and dotting, has the
great advantage that the depth will be uniform, while as compared with etching,
there is the considerable advantage that the contours of the pattern will show the
same distinctness, purity and fineness as if produced by engraving. Another
auvantage of using the sand blast not to be overlooked is the fact that the bottom
of each groove will be perfectly level, while in etching, as is well-known, the acid

page_text: r'
attacks the various elemental constitutents of which, for instance, marble, syenite
and granite consist in different degrees, and fhus produces a surface quite unsuit-
able for the galvanic precipitate, and also very irregular contours..
The grooves produced by the one or the other of these methods are then so
treated that the galvanic precipitate will attach itself more durably to them,
and will be quicker and more regular than would be the case of the precipitating
process were proceeded with immediately after etching or engraving. The
former purpose is effected by so cutting the rims of the patterns, both those
forming the outer contours and those of the bosses, or "islands" of material
remaining within the pattern, (diagram 1, the places marked a) that a section
of the groove will show the form of a trapezium and the "islands" mentioned
the form of an inverted truncated cone or pyramid.
With brittle, easily crumbling ground material, or such the coefficient of
expansion of which differs considerably from that of the metal to be inlaid, the
durability of the inlaid work can be increased by boring into the bottom of the
grooves in different directions, besides cutting the rims. The holes bored fill
with deposited metal, and in consequence of their varying directions further
tend to prevent the falling out of the metal.
In cases where a precious metal is to be inlaid, such as gold, silver or
platinum, this boring would considerably increase the cost of production, as the
holes would, of course take up part of the metal. To prevent this it is intended
to drive into the holes pins of some other metal, the ends of which must how-
ever, not project above the upper ground surface if the pattern is to be produced
by the precipitate alone. But by the aid of these pins new effects in patterns
may be obtained, for instance, by using silver as the inlaying metal and brass
or copper pins, the latter so placed, that after the precipitating process their
ends project above the surface in such places as differently colored spots, or
rows of spots, are desired in the design, as for instance, represented in Fig. 5.
such cases of course, the protruding pins must be filed or cut down after the
precipitating process until their surfaces are on a level with that of the rest.
In
It is clear that where marble, syenite, granite or such like is the ground
material the under-cutting of the rims can be dispensed with if the boring repre-
sented in Fig. 3 or the pins shown in Figs. 4 and 5 are used to increase the
durability.
The durability may also be increased by placing in the grooves of the pattern
metal wire of some kind or a whole net-work of wire. This not only causes a
great saving in deposited metal, but removes another drawback of the galvano-
plastic process which is always very noticeable and has been regarded as unavoid-
able. As is known to every expert, only large even surfaces or large regular
surfaces become uniformly covered with metal in the galvanic process, on
variegated surfaces the gradual accumulation of the metal begins at the corners,
rims and protruding parts, as shown in diagram No. 6. In consequence in pro-
ducing inlaid patterns by the galvanic process a section of a groove representing
a thin line in the pattern would look, after the precipitating process, like the
one shown in Fig. 7, and a large quantity of metal would have to be filed away, or
otherwise removed, if a really even upper surface is desired, because the ridges
of metal at the edges must be left to go on accumulating until they meet, or else
furrows will appear in the lines of the pattern. In the case of wide. grooves
this drawback is, of course, still more noticeable, because, for the reasons.ex-
plained, a a section of one or these would show that such grooves still present the
shape of a trough when narrower ones are already entirely filled up, Fig. 8. Now
if into the broad grooves a netting of wire is placed, Fig. 9.plan view, Fig. 10,
sectional view, and into the narrower grooves, single wires,. (Fig. 11, plan view,
Fig. 12, sectional view), of any kind of metal, the accumulation of the pre-
cipitate is considerably more rapid, and above all more regular, because it also
starts round the wire, so that neither furrows in the narrow grooves nor troughs
in the wiḍe ones are to be feared, because on the one hand the greater part of the
.

page_text: groove is already filled out by the wire, or wire netting, and on the other hand,
as shown in Figs. 10 and 12, only very small, hardly perceptible ridges of metal
are formed, which can easily be polished away with very little waste of material.
As has been mentioned already, laying in these wires and wire nettings also
considerably increases the durability, and this result can be still further increased
in the case of the netting by letting the latter be of the same size, or approxi-
mately so, as the bottom of the groove and then pressing it into the latter,
so that it is held down by the projecting edges, (Fig. 10). The wires and nettings
can be attached to the ground-material very firmly by boring through the latter
in places and passing the wire through (Figs. 13 and 14). If the ground material
is of considerable thickness it will be found more suitable to bore the holes for
passing the wire through in the manner shown in Fig. 15.
It follows herefrom that by this means the effectiveness of the pattern may
be further increased, by using wire of a different color and either bending it or
passing it over elevated portions of the bottom of the grooves, so that it appears
in places at the upper surface. Either the grooves may be made so shallow or
the wire, which need, of course, not be round, may be so thick that the latter
appears at the surface all along, or the wire may be bent so that it only appears
at the surface at certain places. Of course the wire or wires, may be so used that
the visible portions form special figures in the design, as shown in Fig. 16, where
the dotted lines indicate a wire for example, of a different color to the galvanic
deposit.
islands". of
Still more beautiful effects can be obtained by replacing the
material remaining within the pattern by enamel or mother-of-pearl or such like,
or by introducing such like material by mechanical means into the grooves at
certain places. In order to fix the inserted material in such cases more firmly,
it is desirable to make the profiles, as shown in section in Fig. 17 so that they
show rectangular or other offsets. When the various manipulations described,
which prepare the ground material for the precipitating process have been gone
through, the latter process can, of course, only be proceeded with at once if the
ground-material is a good conductor of electricity. If that is not the case it
must be converted into a conductor. This can be done in the same way that the
casts used in the galvano-plastic process are made conductors, i.e. by rubbing, in
graphite, only with the difference that in the present case the deposit is intended
to adhere, while in the galvano-plastic process it must be, easily removable. In
this case, therefore, it is necessary to produce a thin metallic coating, which
will make the surface conducting and at the same time will not prevent the
deposit from adhering to the ground surface, but will further that end. For this
purpose it is desirable to use a metallic silver coating, produced by chemical
action which will penetrate well into the hollows and pores of the material.
The following is an entirely new process for this purpose which consists in
rubbing all parts of the non-conductive material to which the deposit is to adhere
with a style made of soft metal, such as aluminium, zinc, tin, or such like, which
is less expensive and would serve the purpose better.
In consequence of the preparing process described this metal coating would
represent an undetachable binding agent for the galvanic deposit. The galvanic
deposit is then produced in the usual way and after polishing it can of course, be
further embellished with engraving or chasing.
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. A process for producing inlaid work with any desired metal on any desired
material by a galvanic process in such a manner that upon the ground material
grooves are produced by chemical or mechanical action corresponding to the
shape or the pattern to be inlaid, and by a further process these grooves are
partially filled with any desired kind of material, or differently colored material,

page_text: so that the galvanic deposit to follow will adhere to them closely, and take place
quickly and evenly.
2. A form of the process indicated in Claim 1, in which the grooves which are
to receive the galvanic deposit are produced on the ground surface by means of
a sand blast.
3. A form of the process indicated in Claim 1, in which the grooves in the
ground surface are so undercut that a section of the groove will show the edges
in the form of a trapezium.
4. A form of the process indicated in Claim 1, in which the ground surface
is bored into in various slanting directions in such a manner that the holes
represent diverging continuations of the space to be taken up by the galvanic
precipitate.
5. A form of the process indicated in Claim 1 in which pins of less valuable
material are driven into the holes mentioned in Claim 4, in such a manner that
either their heads only reach above the bottom of the grooves, or, for the purpose
of further ornamentation, above the upper surface.
6. A form of the process indicated in Claim 1, in which wires are placed in
the narrower grooves in the ground surface and wire netting in the broader
grooves, the wires in the former grooves being fixed by passing the ends through
holes in the ground material, and the wire netting by being pressed into the
grooves.
66
$6
33
7. A form of the process indicated in Claim 1 in which the wires mentioned
in Claim 6 are sewn "into the ground-material, in the manner of embroidery.
8. A form of the process indicated in Claim 1, in which the islands of
material remaining between the grooves of the design are replaced by enamel or
mother-of-pearl or some other substance differing from that of the ground-
material, or in which such substance is introduced at certain places into the
grooves which are to receive the galvanic precipitate in such a manner as to fill
up the said grooves at the said places.
9. A form of process as indicated in Claim 1 in which the employment of non-
conducting or badly conducting substances as ground-material is made possible
by rubbing those places on the said ground material to which the galvanic pre-
cipitate is to adhere with a style made of soft metal, and thus rendering them
conducting.
1000
HERBERT HADDAN & Co.,
Agents to Applicant, 18, Buckingham Street, Strand, London.