Improvements in Electric Heating Devices.
Year: 1897

page_text: Date of Application, 18th Feb., 1897
Complete Specification Left, 18th Nov., 1897-Accepted, 18th Dec., 1897
Improvements in Electric Heating Devices.
I, WILLIAM EDWIN HEYS of 70, Market Street, Manchester, in the county of
Lancaster, Chartered Patent Agent, do hereby declare the nature of this invention
to be as follows:
This Invention relates to an Improved Electric Heater which has been especially
designed for use in Electric Tramway and Railway Vehicles, in Electric carriages,
and in other vehicles and suitable places where electric current is available.
The apparatus constructed according to this Invention may be of any dimensions
and of any convenient forin, such for example as that of a plate or tube. Its basis is
Asbestos cardboard upon which is wound any suitable metallic wire, the dimensions of
which have been calculated to give the electrical resistance necessary for the
required temperature. This wire covered basis is again covered with an asbestos
envelope, and the whole is enclosed in a metallic envelope which is preferably
hermetically closed to prevent the entry of moisture.
The wire on the basis is connected by its ends to terminals such as metallic
eyelets, to which also the leading in wires are connected.
Dated this 17th day of February AD 1807
Improvements in Electric Heating Devices.
I, WILLIAM EDWIN HEYS of 70, Market Street, Manchester in the county of
Lancaster, Chartered Patent Agent, 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 an improved electric heater which has been especially
designed for use in electric tramway and railway vehicles, in electric carriages,
and in other vehicles and suitable places where electric current is available.
Its
The apparatus constructed according to this invention may be of any dimensions
and of any convenient form, such for example as that of a plate or tube.
basis is asbestos cardboard upon which is wound any suitable metallic wire the
dimensions of which have been calculated or found to give the electrical resistance
necessary with the given pressure of current, to produce the required temperature.
This wire covered basis is again covered with an asbestos envelope which is preferably
hermetically closed to prevent the entry of moisture.

page_text: The wire on the basis is conneeted by its ends to external conductors or to
terminals such as metallic eyelets to which also the leading in wires are
connected.
The accompanying drawings represent one type of electro-calidor or electric warmer
constructed according to the present improvements,
Figure 1 shewing a front view with the cover lifted away:
Figure 2, a section along the line 1-2, and
Figure 3, an elevation with the covering envelope shewn as about to be closed,
The asbestos card-board basis A may have any suitable dimensions and the wire
conductor B may be wound upon it as indicated. To prevent contact with the wire B,
it is advantageous in this form of the appliance, to wind it into notches or slits N,
formed in the edges of the board A. The two ends of the wire may be coiled around
the two metal eyelets C C, and be clinched in the thicknes of the cardboard in the act
of closing the eyelets. The external conducting wires F F, may also be respectively
coiled around the eyelets, and be similarly secured by clinching. These two
wires may be connected with any suitable terminals or means for connecting them
with the wires of the electric circuit as is well understood. The wires will of course
be insulated or prevented from coming into contact with each other and short
circuiting.
The cardboard basis being thus prepared, there is cemented upon each of its two faces
by means of a layer of silicate of potash, another asbestos cardboard E of appropriate
thickness and of the same surface dimensions as the board A. The new electro-
calidor has then the appearance of a thick ordinary asbestos cardboard from one end
of which the wires F F, protrude.
The covered card is then enveloped with any suitable sheet metal whatever, D,
such as copper, tinned iron, galvanised iron, brass, aluminium and the like, of such
thickness as may be required for the object to be attained taking care to provide for
the insulated passage of the wires F F₁. The metallic cover is then clamped folded
brazed or soldered along its edges or joints so as to prevent the entry of moisture and
the electrocalidor is complete.
The appliance can be constructed to utilise currents of any pressure or density
desired and to give almost any required degree of heat within reasonable limits.
Instead of the permanent metallic envelope herein before described, the electro-
calidor may be inserted during use into any suitable metallic case or wariner or
within any other equivalent cover.
If the electrocalidor is required to have a tubular or cylindrical form the wire B is
wound upon an asbestos tube which is then enclosed by a second larger asbestos
tube, and finally by a metallic cover in substantially the same manner as described
for the flat heater. Other forms or shapes may also be constructed with the necessary
and obvious variations in like manner.
Having now particularly described and ascertained the nature of my said Inven-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is :-
An electrocalidor or electric heater, consisting of an asbestos cardboard basis upon
which an electric conductor is wound, asbestos cardboard covers secured on the basis
so as to cover the conductor, an external metallic casing, and connections for closing
the electrocalidor circuit: substantially as herein before described with reference to
the accompanying drawings.