Improvements in Electric Heaters.
Year: 1896

page_text: Date of Application, 8th Sept., 1896-Accepted, 9th Jan., 1897
Improvements in Electric Heaters.
We, JOHN EMORY MEEK, Electrician and THE H. W. JOHNS MANUFACTURING
Co. both of 87 Maiden Lane, New York City, United States of America 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 electric heaters for heating the atmosphere in a chamber
or compartment of any kind, and more especially is designed for use in electrically
propelled street cars.. The disadvantage under which many forms of electric heaters
for street cars heretofore made suffer, is the fact that, from their bulkiness and other
features of construction, it is impracticable to spread the heating surface over a
sufficient area of the car, but said heating surface is concentrated into two or four
heaters, with the result that said centre of radiation is overheated, while other
portions of the car are cold. To overcome this difficulty and obtain a heating surface
which will be uniformly distributed through the car, and which shall take up little
room and be cheap in construction, I have designed the form of apparatus illustrated
in the accompanying drawings.
.
A preferred form of the invention, more especially designed to provide a
convenient form of heater to be placed under the seats of street cars of the type in
which-the-said-seats-aré-placed-crosswise-of- the-car,-is-shown in Figures 1-to-6,
inclusive, of the drawings. The forms of electric heaters heretofore in general use
have been so complicated that the question of division so as to place one under each
cross-seat in a car has been one of some practicable difficulty. To avoid this and
produce a heater which shall be light, compact, and capable of such arrangement, I
have designed the form illustrated in the said figures of the drawings.
Figure 1 is a plan view of the heater, with a portion of the casing removed.
Fig. 2. is a cross section on line 2-2 of Fig. 1.
Fig. 3 is a cross section on line 3-3 of Fig. 1.
Fig. 4 is an enlarged detail view of a portion of the heater with parts broken
away.
Fig. 5 is a cross section on line 5 of Fig. 4.
Fig. 6 is a cross section on line 6-6 of Fig. 4.
Fig. 7 is a front elevation of one of the heaters, with a portion of the casing broken
away at the right hand end.
Fig. 8 is a cross section on line 8-8 of Figure 7.
Figure 9 is a cross section on line 9-9 of Fig. 7.
Fig. 10 is an enlarged detail view of a portion of the heater, other portions being
broken away.
Fig. 11 is a cross section on line 11-11 of Fig. 10.
The main feature of the invention consists of a woven fabric of asbestos or other
insulating and incombustible fibre in the woof thread of which is embedded an electric
conductor. This electric conductor is preferably a fine metal wire which has been
covered with asbestos yarn by weaving, winding or braiding. This fabric, with the
embedded conductor, is cut into sections and attached to any suitable backing such
as asbestos millboard, either by cementing, stitching or tacking it to the same, and

page_text: "size" or other material for stiffening the fabric, rendering the asbestos fibre
waterproof and otherwise fitting the fabric to withstand the conditions of use. This
treatment may be by "japanning," or any other method well known in the arts. The
fabric so stiffened and attached to the backing of the insulating and incombustible
board is then preferably placed in some light metal case to protect it from abrasion,
and the case is then attached to the front of the longitudinal seats in the ordinary
form of street car, or disposed about any room or chamber which is to be heated.
In the form shown in Figures 1 to 6, the conductor is omitted along certain portions
of the fabric, and the latter is bent over in folds along these portions, thus forming a
compact, powerful heater.
Throughout the drawings, like reference figures refer to like parts.
1 is the inclosing frame or case of the heater, which may be made of light sheet iron
or wire or some other metal construction.
2. generally is the woven fabric of asbestos fibre, which is bent into several
folds, 2, 2, 2. These folds are kept at proper distances one from the other, and
given additional insulation one from the other by the interposing strips, 3, which may
be of asbestos millboard or hard fibre or other insulating material.
4-4 are little knobs or projections on the frame, 1, and serving as means of lifting
the same slightly from the floor when the heater is placed upon the same.
5-5 are the terminals of the one section of the electrical conductor embedded in
the woof thread of one of the folds of the heater. This wire or other electrical
conductor is omitted from the woof thread of the fabric along the lines 6-6 on
which the folding of the fabric occurs, and if desired, a portion of such fabric may
be cut away along said lines of folding, as is shown in Fig. 5.
7 is a bolt, and 8 is a nut co-acting therewith to hold the various parts of the metal
shell, 1, together, as shown in Fig. 5.
9 is a layer of asbestos millboard or other insulating material placed inside of the
heater shell, and on which the lower part of the heater rests.
10-10 are air spaces left between the folds of the fabric.
11 is a piece of hard fibre, or other insulating substance in which the binding
screws 12-12 for the electric connections are mounted. The fabric containing
the electrical conductor is treated with any proper "size" or material for stiffening the
same and rendering the fibre waterproof before the said fabric is bent into the folds
shown. The substance which I have used for this apparatus is what is known as
"japan." The various sections electrically separated one from the other, formed
by the folds and arrangement of the conductors above described, may be connected
together at their terminals, 5-5, in series or in multiple arc, as is preferred.
I prefer, however, to connect corresponding sections of the different heaters placed
under the various seats of the car in series, so that the heating current may be
sent through the bottom fold of each heater in the car, or through the bottom fold
and the one next to it in each heater, and so on. In this way, an equable distribution
of the heat, whether the same is great or small, is produced.
The method of operation of this form of the invention is of course clear from
the foregoing description. The heaters are placed under the seats, and may be
loose or fastened. The terminals of the electrical conductors are connected as may
be desired, and thrown into circuit with the current from the source of supply to
the car motor.
The before described form of the invention is, as before stated, more especially
designed for use under seats and chairs, or for movable heaters. The form shown
in Figs. 7 to 11 is more especially designed for attachment to the walls of the
chamber to be heated. Referring to the drawings:-
13 represents generally a section of a woven fabric of asbestos with a metallic wire
embedded in the woof of said fabric and serving as an electrical conductor. The
terminals of the wire running through each section of the fabric are represented at
14 and 14. Of course, there are as many separate sections of said wires as there
are sections of the heater, and they may be connected together either in series or in
multiple arc, as desired.

page_text: 28 is the insulating asbestos or other fibre of the woof thread surrounding the
conducting wire, 14, as best shown in Figs. 10 and 11.
15 is a backing of any kind of incombustible board, such as asbestos mill-board; to
which the asbestos fabric is attached, either by pasting, stitching or tacking.
16 is a light sheet iron or wire or other metal frame placed over the heater, and
having the openings, 17, through which the heated air may escape from the interior
of the heater. This frame or shell, 16, is attached to the metallic back, 18, by means
of the bolts, 19, and the nuts 20, and in conjunction therewith forms a metallic shell
or inclosing frame for the heater.
21 (Fig. 7) represents a strip or section through, the woven fabric in which the
conductor, 14, is omitted from the woof thereof. This forms a heater into two
electrically separate sections, each having its closed circuit, of conductor, 14. Of
course, the conductor may be omitted from other intervening portions of the woof
of the fabric, and thereby are formed as many different sections as desired in the
heater.
22 (Fig. 11) represents the "size," or other stiffening and water-proofing substance,
such as
japan," which protects the insulation from the action of moisture and
gives the fabric a desirable stiffness, sufficient to render it self-supporting independent
of the backing, 15, if necessary.
The method of operation of this general form of my invention is evident. The
heaters are fixed to the walls of the room or to the side of the seat, or to any other
convenient object, and, on account of the slight thickness of the heater and its
complete insulation, it cannot overheat the occupants of the room or the passengers
of the car, even if their clothing is pressed against the face of the heater.
A number of heaters are distributed throughout the room or the car, and thereby
the amount of heat necessary from each heater is reduced and the possibility of an
uncomfortable degree of local temperature avoided.
The conductors, 14, 14, of the various sections are connected up in any proper
way, but preferably similar sections of different-heaters-are-connected in-series,.so.
that one section of each heater may be thrown in to produce a low temperature and
two or more sections of each heater to produce higher temperature.
In that way the temperature will be equable throughout the room or the car
whether high or low, and the disadvantages resulting from the usual method of cutting
out one or more heaters entirely, while others are radiating their full amount of heat.
are obviated.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what I
claim is :-
1. An electric heater, which consists of a woven fabric of asbestos or similar
incombustible and insulating fibre, with an electric conductor embedded in the woof
of the fabric, the said fabric being folded upon itself one or more times and having a
proper quantity of "size" or other stiffening material applied thereto, to render it
inflexible, substantially as described.
2. An electric heater, which consists of a woven fabric of asbestos or similar
incombustible and insulating fibre, with an electric conductor embedded in the woof
of the fabric, the said fabric being folded upon itself one or more times and having a
proper quantity of "size" or other stiffening material applied thereto, to render it
inflexible, said fabric being divided into two or more electrically separate sections by
the omission of the conductor from the thread of the woof along and adjacent to the
line of each fold, substantially as described.
3. An electric heater, which consists of the combination of a woven fabric of
asbestos, or similar incombustible and insulating fibre, with an electric conductor
embedded in the woof of said fabric, and a backing of incombustible millboard to
which said fabric is attached, said fabric having a proper quantity of "size" or other
material for stiffening applied thereto substantially as described.

page_text: .: 4. An electric heater, which consists of the combination of a woven fabrio of
asbestos, or similar incombustible and insulating fibre, with an electric conductor
embedded in the woof of said fabric, and a backing of incombustible millboard to
which said fabric is attached, said fabric having a proper quantity of "size" or
other material for stiffening applied thereto, said fabric being divided into two or
more electrically separate sections by the omission of the conductor from the inter-
vening threads of the woof, substantially as described.
Dated this Eighth day of September 1896.
For the Applicants,
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent.Agent..