Improvements in and relating to Electric Heaters.
Year: 1895

page_text: Date of Application, 28th May, 1895-Accepted, 6th July, 1895
COMPLETE SPECIFICATION.
Improvements in and relating to Electric Heaters.
I, CHARLES JOHN REED, of No. 441 Chestnut Street, Philadelphia, in the
County of Philadelphia, and State of Pennsylvania, United States of America,
Electrician, 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 :-
My invention relates to electric heaters and is illustrated in the accompanying
drawing in which
Figure 1 is a side elevational view illustrating the application of my improvement
in the simple form of radiator, while
Figure 2 is a perspective view partly broken away of a glass tube illustrating
the manner of constructing my improved heating apparatus.
B represents the base of the heater, preferably of metal, and A a heat radiating
tube either of glass or porcelain, or analogous non-conducting material, said tube
being disposed in a similar manner to well known forms of heat radiating tubes and
attached to the base B by yokes or eyes C.
D represents the conducting or neck portion of a socket, analogous in all respects
to well known forms of incandescent lighting sockets, and S the stationary part of
said socket, a key being provided, as shown, for connecting the current feeders in
circuit with the conductors w w which are secured at their inner ends to the con-
ducting portions of the socket in the usual manner, their outer ends being connected
to the inner surface and lower ends of the tube A, said inner surface being as
shown in Figure 2, a thin coating or film of silver and electro-plates with copper at
the lower ende.
In the construction of my improved form of heater, I deposit a thin coating or
film of metal by any well known depositing process, such as is well understood for
instance in the art of silvering mirrors. A silver solution is first prepared by
dissolving ten grams of nitrate of silver in 100 grams of water. To this, I add
160 grams of caustic soda solution prepared by dissolving 20 grams of caustic soda
in 500 grams of water. I then add ammonic hydrate enough to re-dissolve the
precipitate until it becomes nearly clear. I then add enough water to make
1200 cubic centimeters. I now prepare a reduction solution by boiling 25 grams of
white sugar in 200 grams of water and add, while boiling, 1 & 33-100ths grams of
nitric acid, the boiling continuing preferably about twenty minutes. When cold,
I add 50 grams of alcohol and water enough to make 500 cubic centimeters. I now
proceed in the process of silvering by mixing 100 parts of the above described
silver solution with 10 or 12 parts of the above described reduction solution, and
then fill the tube A with this solution, allowing it to stand a sufficient time for the
silver to deposit on the inner surface of the tube.
The thickness of this deposit, and hence its conductivity, will depend of course
upon the proportions of the solution and the length of time it is allowed to stand
in the tube.
The above named process of silvering glass and analogous surfaces is well
known in the art of mirror making and constitutes no part of my inveution,
the same being described here for the purpose of illustrating the manner of
constructing my novel form of heater.
After the interior of the tube has been thus silvered or coated with a thin
conducting deposit, I alternately immerse the ends of the tube in an electro-plating

page_text: bath and deposit thereon an additional surface of copper as shown in Figure 2,
this process of electro-plating being also well understood by those skilled in that
art. By thus plating the inner ends of the tube, I afford a simple and efficient
means of attaching the outer ends of the conductors w by soldering, as will be well
understood by those skilled in the art.
While I have shown my invention arranged in the form of a radiator, it is to be
understood that it may be used in many well known ways; to illustrate, it might
be arranged for use in connection with flat-irons, water-heating vessels, and
in fact in any place where heating implements are now used in the art of electric
heating.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what: 1
'claim is -
1. An electric heater consisting of a heat radiating tube having a conducting
lining attached to its inner surface, the opposite ends of said conducting lining being
connected to current conductors.
2. An electric heater consisting of a non-conducting tube having an interior
coating of conducting material which coating is attached at its opposite ends to
current conductors.
3. An electric heater consisting of a glass tube having a thin conducting film of
silver deposited on its inner surface, said film being connected at the opposite
end of the tube to conductors which lead to a source of current supply.
4. An electric heater consisting of a non-conducting tube having a thin film or
coating of silver attached to its inner surface, said 'film being connected at its
opposite ends to conductors leading to a source of current supply.
5. An electric heater consisting of a non-conducting tube bent in zigzag form
after the manner of an ordinary radiator and coated on its inner side with a thin
conducting film, the opposite ends of which film are connected to a source of
electrical energy.
6. An electric heater consisting of a glass tube having a thin film or coating of
silver on its inner surface, the opposite ends of which are connected to a source of
electrical energy, said tube being bent back and forth upon itself in the form of an
ordinary radiator, substantially as described.
Dated this 28th day of May 1895.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.