Improvements in the Manufacture of Balance Wheels for Watches and Chronometers.
Year: 1887

page_text: Date of Application, 14th Nov., 1887
Complete Specification Left, 13th Aug., 1888
Complete Specification Accepted, 14th Sept., 1888
Improvements in the Manufacture of Balance Wheels for Watches
and Chronometers.
We, HEINRICH OSTERMANN, and AXEL PRIP, both of Geneva, in Switzerland, do
hereby declare the nature of this invention, to be as follows:-
The purpose of our invention is to have the balance wheel of watches and chrono-
meters made non-magnetic and unoxidisable, with a view to avoid the disturbances
produced in the working of the watch by dynamo-electric machines, and by oxidation.
Therefore, it is necessary to have two non-magnetic and unoxidisable metals or
alloys having similar qualities, as steel and brass, for the purpose of manufacturing
well compensated balance-wheels. The most important condition which is to be
obtained is a dilatation corresponding exactly with the dilatation of steel and of
brass.
We are aware that non-magnetic balance-wheels composed of palladium alloys in
place of steel, and of silver, in place of brass, have been made. But the dilatation of
steel being 0.0011 to 0.00115 the dilatation of the palladium alloy is 0.00135
to 0.001375, that is to say there is a difference of 0.0002 between the dilatation of
these two metals. We are also aware that the said difference is partly compensated
for by the inverse difference existing between silver and brass. The dilatation of
silver being 0.0019 to 0.00195, the dilatation of brass will be 0.00185 to 0.00190,
that is to say, a difference of 0.0001 which is to be subtracted from the aforesaid
difference. But there is still a difference between those balance wheels and the well
compensated steel and brass balance-wheels, and the purpose of our invention is to
obtain a perfectly compensated non-magnetic balance-wheel made of alloys which are
easily worked up.
We form the inner blade of the balance of an alloy composed of platinum, nickel,
copper and cadmium; or of platinum, nickel copper, cobalt and cadmium, to which
may be added, in small proportions, some other metals, without changing the qualities

page_text: of the alloy. The principal part of the alloy is platinum. The nickel and cobalt may
be replaced by gold; and the copper may be replaced by silver, but the best result
is obtained by means of the aforesaid alloy combined in the following proportions:
to which are added 3.50° cadmium.
°
The alloys containing cobalt and those which contain more nickel and less platinum
are harder than those which contain no cobalt, or little quantities of nickel.
The melting is effected in a crucible furnace under the action of compressed air.
The nickel, copper, and cobalt are first combined with one half of the aforesaid pro-
portion of platinum and with powdered charcoal, and melted together. The other
half part of the platinum is added afterwards, in the form of thin rolled plates, and
then the cadmium is thrown into the molten mass. Part of it (perhaps one half) will
be gasified and be lost, whilst the other part will be absorbed by the molten mass.
The linear dilatation of the specified alloy will be the following: for A and B, at
or about 0.001125; for C and D, at or about 0.001175; for E and F, at or
about 0.0012.
In combination with the hereinbefore specified composition of the inner blade of
the balance, we make the outer blade of an alloy composed essentially of cadmium and
silver, or of cadmium, copper, and silver combined in variable proportions.
Dated this 11th dow of Naumbo. 1007
ERNEST DE PASS, Fel. Inst. P.A.,
68, Fleet Street, London,
Agent for the Applicants.

page_text: COMPLETE SPECIFICATION.
Improvements in the Manufacture of Balance Wheels for Watches
and Chronometers.
We, HEINRICH OSTERMANN and AXEL PRIP of Geneva in Switzerland, 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 :-
The purpose of our invention is to enable the balance wheel of watches and chrono-
meters to be made non-magnetic and unoxidisable with a view to avoid the disturbances
produced in the working of the watch by dynamo electric machines and by oxidation.
It is therefore necessary to have two nonmagnetic and unoxidisable metals or alloys
having similar qualities, as steel and brass, for the purpose of manufacturing well
compensated balance wheels. The most important condition which is to be obtained
is a dilatation corresponding exactly with the dilatation of steel and of brass.
We are aware that non magnetic balance wheels composed of palladium alloys in
place of steel, and of silver in place of brass have been made but the dilatation of
steel being 0-0011 to 0.00115 the dilatation of the palladium alloy is 0.00135 to
0.001375 that is to say there is a difference of 0.0002 between the dilatation of these
two metals. We are also aware that the said difference is partly compensated for by
the inverse difference existing between silver and brass. The dilatation of silver
being 0.0019 to 0.00195 the dilatation of brass will be 0.00185 to 0.00190, that is
to say a difference of 0.0001 which is to be subtracted from the aforesaid difference.
But there is still a difference between those balance wheels and the well compensated
steel and brass balance wheels, and the purpose of our invention is to obtain a
perfectly compensated non-magnetic balance wheel made of alloys which are easily
worked up.
We form the inner blade of the balance of an alloy composed of platinum, nickel,
copper, and cadmium, or of platinum, nickel, copper, cobalt, and cadmium to which
may be added in small proportions some other metals without changing the qualities
of the alloy. The principal part of the alloy is platinum. The nickel and cobalt
may be replaced by gold; and the copper may be replaced by silver, but the best
result is obtained by means of the aforesaid alloy combined in the following
proportions:-

page_text: to which is added 3.50% cadmium.
The alloys containing cobalt and those which contain more nickel and less platinum
are harder than those which contain no cobalt or little quantities of nickel.
The melting is effected in a crucible furnace under the action of compressed air.
The nickel, copper, and cobalt are first combined with one half of the aforesaid pro-
portion of platinum and with powdered charcoal, and melted together. The other
half part of the platinum is added afterwards in the form of thin rolled plates and
then the cadmium is thrown into the molten mass. Part of it, (perhaps one half)
will be gasified and be lost whilst the other part will be absorbed by the molten mass.
The linear dilatation of the specified alloy will be the following: for A and B at or
about 0.001125; for C and D at or about 0.001175; for E and F at or about 0.0012.
In combination with the herein before specified composition of the inner blade of
the balance we make the outer blade of an alloy composed essentially of cadmium
and silver, or of cadmium, copper, and silver combined in variable proportions.
The improved alloy when composed of platinum, copper, nickel and cadmium or of
platinum, copper, nickel, cobalt, and cadmium may be used for manufacturing other
parts of the escapement which are in relation with the balance wheel.
Having now particularly described and ascertained the nature of our Invention,
and in what manner the same may be performed, we declare that what we claim is :-
1. A non magnetic and unoxidisable compensating balance wheel for watches and
chronometers having its inner blade made of an alloy composed essentially of platinum,
copper, nickel and cadmium, or of platinum,copper, nickel, cobalt and cadmium, as specified.
2. A non magnetic and unoxidisable compensating balance wheel for watches and
chronometers having its outer blade made of an alloy composed essentially of cadmium
and silver, or of cadmium copper, and silver.
3. A non-magnetic and unoxidisable compensating balance wheel for watches and
chronometers having its inner blade made of an alloy composed essentially of
platinum, copper, nickel, and cadmium or of platinum, copper, nickel, cobalt and
cadmium and its outer blade made of an alloy composed essentially of cadmium
and silver, or of cadmium, copper and silver.