Year: 1896

page_text: !, Dr. CHARLES ALBERT TIMмE, of 30 West 59th Street, New York, in the
United States of America, do hereby declare the nature of this invention to be as
follows:-
This invention relates to the construction of an electric furnace or oven chiefly
designed for use in the manufacture of artificial teeth and plates or bases.
According to my invention I provide a shell or chamber, the lining of which is
composed of separate heating plates in which the wires for conducting the electric
currents are embedded, preferably arranged in parallel, so that the heating effect
of each plate or surface can be separately regulated.
By this construction the plates forming the lining of the furnace or oven can be
easily arranged so as to be exchangeable whereby plates which become damaged
by the high temperature of about 2000° C attained when employing the oven
for porcelain enamelling on platinum, can be easily replaced by fresh ones and
instead of the usual materials hitherto employed in the manufacture of the plates
such as asbestos or alumina I employ infusorial earth in layers of different degrees
of granulation or porosity.
To enable my invention to be fully understood I will describe it by reference
to the accompanying drawing, in which :-
Figure 1 is a perspective full size view of my furnace or oven;
Figure 2 is a longitudinal section to a reduced scale; and
Figure 3 is a horizontal section of the same.
A is the metal shell or chamber, B the cover of the same, L1, L2, L3, L' are the
separate heating plates forming the lining and in which the platinum wires p
for conducting the current, are embedded. The terminal screws q, q, q', q' for
the wires are arranged in the front of the apparatus at the side of the cover.
cover B rests on the bottom of the shell or chamber and is provided with a
window S which is closed by means of a plug C when the furnace is in use.
The
As shewn in Figures 2 and 3 the infusorial earth is divided into layers in the
manufacture of the heating plates in such a manner that the compactness or density
decreases from the interior towards the metal shell or chamber. This has the
advantage that the plates only give up their heat towards the interior whilst
towards the exterior on account of the increasing degree of porosity, a circulation
of air is set up whereby less heat is communicated to the metal shell or chamber.
From Figure 1 it can be seen that each heating plate can be easily switched off
during the working of the oven, it being only necessary, after the cover B has been
removed, to loosen the screws in connection with the plate to be switched off, so
that when the said plate is removed the wires attached to it are pulled out of the
terminals.
The teeth plates or bases to be heated are placed directly on the lower heating

page_text: plate L and by switching off one or more of the heating plates the degree of heat
can be regulated to suit the coating of enamel to be applied.
Dated the 2nd day of October. 1896.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
An Electric Furnace or oven.
I, Dr. CHARLES ALBERT TIMME, late of 30 West 59th Street New York, in the
United States of America, now of 62 and 63, Unter den Linden, Berlin, in the
German Empire, 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:-
This invention relates to the construction of an electric furnace or oven chiefly
designed for use in the manufacture of artificial teeth and plates or bases.
According to my invention I provide a shell or chamber, the lining of which is
composed of separate heating plates, in which the wires for conducting the electric
currents are embedded, preferably arranged in parallel, so that the heating effect
of each plate or surface can be separately regulated.
By this construction the plates forming the lining of the furnace or oven can be
easily arranged so as to be exchangeable whereby plates which become damaged
by the high temperature of about 2000° C attained for instance when employing
the oven for porcelain enamelling on platinum, can be easily replaced by fresh ones
and instead of the usual materials hitherto, employed in the manufacture of the
plates such as fire clay I employ infusorial earth in layers of different degrees
of granulation or porosity..
To enable my invention to be fully understood I will describe it by reference
to the drawing filed with my Provisional Specification in which :-
Figure 1 is a perspective full size view of my furnace or oven;
Figure 2 is a longitudinal section to a reduced scale; and,
Figure 3 is a horizontal section of the same.
A is the metal shell or chamber, B the cover of the same L, L, L, L are the
separate heating plates forming the lining and in which the platinum wires p
for conducting the current, are embedded. The terminal screws q, q, q', q¹ for
the wires are arranged in the front of the apparatus at the side of the cover.
cover
The
B rests on the bottom of the shell or chamber and is provided with a
window S which is closed by means of a plug C when the furnace is in use.
As shewn in Figures 2 and 3 the infusorial earth is divided into layers in the
manufacture of the heating plates in such a manner that the compactness or density
decreases from the interior towards the metal shell or chamber. This has the
advantage that the plates only give up their heat towards the interior whilst
towards the exterior on account of the increasing degree of porosity, a circulation
of air is set up whereby less heat is communicated to the metal shell or chamber.
The infusorial earth which I advantageously use for the heating plates is a
granular mass used for foundry sand and for pottery ware. The plates can be
advantageously manufactured by sifting the material in layers into a mould of
suitable size, the said material being slightly moistened before or after being
introduced into the mould. For the lower layers coarser grained material is
employed and is filled in to the proper depth before the heating wires are inserted.
When the mould is filled the material is heated in an oven until the particles
thereof become baked together and the plate forms a cohesive whole.

page_text: From Figure 1 it can be seen that each heating plate can be easily switched off
during the working of the oven, it being only necessary, after the cover B has
been removed, to loosen the screws in connection with the plate to be switched
off, so that when the said plate is removed the wires attached to it are pulled out
of the terminals.
The teeth plates or bases to be heated are placed directly on the lower heating
plate L and by switching off one or more of the heating plates the degree of heat
can be regulated to suit the coating of enamel to be applied.
It will be obvious that my improved electric furnace or oven can to put to many
uses other than that above described, that is to say, that it can be employed under
any circumstances where high temperatures are required and where the heat is
required to be cut off or interrupted at a particular moment. Amongst this class
of work I may mention, for example, fine mechanical work, the incrustation of
bodies, the union of bodies composed of metals which are with difficulty soldered
and the observation of the chemical formation and decomposition of mineral,
vegetable and animal bodies.
In cases where it is necessary to accurately follow the successive changes in the
temperature a pyrometer is introduced into the chamber of the oven or furnace
at each separate stage in the process the wires of which pyrometer are in connec-
tion with a galvanometer so as to operate the needle or pointer thereof.
temperature attained by the article in the oven or furnace can then at any moment
be read off in degrees on the scale by the operator.
The
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:-
1. An electric furnace or oven wherein the heating plates form a lining to the
furnace shell or chamber and are so arranged that a plate, should it become
damaged, can be removed and replaced by a new one without interfering with the
operation of the furnace or oven substantially as described and illustrated.
2. In an electric furnace or oven of the kind described in Claim 1 the employ-
ment of heating plates made of infusorial earth in such a manner that their
compactness or density decreases from one side to the other so as to create a
circulation of air towards the shell of the furnace or oven as described and
illustrated.
3. The manufacture and use of the improved electric furnace or oven herein-
before described and illustrated in the accompanying drawing.
1007
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.