Improvements in Devices for Heating and Cooking by Means of Electricity, including Electric Flat Irons and other Articles.
Year: 1890

page_text: Date of Application, 25th Mar., 1890-Accepted, 12th July, 1890
COMPLETE SPECIFICATION.
Improvements in Devices for Heating and Cooking by Means of
Electricity, including Electric Flat Irons and other Articles.
We HENRY RICE BUTTERFIELD & WILLIS MITCHELL of Waterville in the County
of Kennebec, State of Maine, United States of America, Electricians, do hereby
declare the nature of our invention for "IMPROVEMENTS IN DEVICES FOR HEATING
AND COOKING BY MEANS OF ELECTRICITY INCLUDING ELECTRIC FLAT IRONS & OTHER
ARTICLES and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
"
The first part of this invention relates to devices for cooking and heating by
means of electricity; and its object is to simplify and cheapen such devices and
render them more effective. To this end I enclose a layer of continuous wire arranged
in coils, between two layers of asbestos and give to the material thus produced the
shape of an oven a broiler or other cooking utensil article or structure, the ends of
the coil being also protected by asbestos or other insulating material and the wire
connecting terminally with circuit wires so that a current of electricity will pass
through it.
In the accompanying drawing
Figure 1 represents a cylindrical oven or cooking device embodying our invention
the outer layer of asbestos or other insulating material being partly opened and turned
away to show the wire ;
Figure 2 represents a longitudinal section through the same;
Figure 3 represents in perspective a rectangular oven constructed according to my:
invention, the outer layer of asbestos or other insulating material being partly opened
as in Figure 1.
Figures 4, 5 and 6 represent detail perspective views of flat irons, an upright
cylindrical beater and a broiler each having the outer layer removed in part to show
the wire and each constructed according to my invention.
Figure 7 represents in perspective view a stove having an oven and cylindrical
heaters for pot holes according to my invention.
In Figs. 1-2-3-4-5-6 & 7 A designates the exterior layer of asbestos, or
cther insulating material B the interior layer, the coiled wire between them from
which I get the best results when left quite naked, D the ends of said wire connecting
with the wire of the electric circuit, and E the strips connecting the ends of the
asbestos layers in order that the coil of wire as a whole may be completely enclosed.
For most purposes I prefer a cylindrical device like that shown in Figures 1—2
and 5. When used as an oven it is arranged horizontally and the ends may be
closed in any convenient way or left open as shown. The outer and inner layers are
of course cylindrical and the end strips E are flat rings. The coil of wire as a
whole has a cylindrical form. When used for heating, the cylinder is set upright as
in Figure 5 and supported by short legs G.
The rectangular oven shown in Figure 3 differs mainly in shape from that above
described, the principle being the same. It is provided with an oven door H, open
in said figure.
In winding a naked wire on the inner layer B of insulating material care must bo
taken to keep the coils from touching to prevent short circuiting. The wire may be
covered with insulating material also if desired. Or when two layers of naked wire
are used it will be found convenient to separate the coils of the outer layer by small.
pieces of insulating material, and to insert the same between the outer and the inner'
layer of wire, or to wind one thickness of the inner wall of insulating material
between the layers of wire.
As shown in Figure 4, the lower part of a flat iron may consist of two flat layers
of asbestos with the coil between them and connected at the edges by strips.

page_text: As shown in Figure 6 two flat plates or layers of asbestos may have the wire
between them and be connected by strips of asbestos, as above, at the edges, the
whole constituting a composite heating and cooking plate adapted to receive a frying
pan, a gridiron or other utensil of similar use.
These figures will suffice to illustrate the varied applicability of my invention,
but many different articles used in cookery or for similar purposes may be constructed
in this way. The heat is generated by the resistance to the passage of the electric
current and the asbestos or other insulating material protects the wire from contact
with any external body, and insulates it as a whole electrically, although the wire is
not covered throughout its length, and although sufficient heat is allowed to escape
through the asbestos or other insulating material for heating and cookery.
This electric cooking device is very durable, since the wire of course cannot burn
the asbestos, and the asbestos preserves the wire from rusting and from injury.
My olectric heating device may be used for heating buildings and for all analogous
purposes.
Another part of this invention has for its object to provide an improved electric
heater and radiator, suitable for warming rooms, halls and other spaces. To this end
we wind the electric wires on studs, rings frames or other supports in such a way as
to form a wire network allowing the passage of air through it, but in circuit as a
continuous conductor and offering a considerable degree of resistance to the electric
current. The details of our invention will be hereinafter particularly set forth, as
embodied in the preferred constructions; and the said invention will be defined in the
appended claims.
In the accompanying drawings Figure 8 represents a perspective view of a
radiator embodying the said invention, the same being ready for use.
Figure 9 represents the said radiator in perspective the exterior casing being
removed;
Figure 10 represents the base and interior frame in perspective;
Figure 11 represents a detail perspective view of the interior frame detached from
said base; and
Figure 12 represents a side elevation of a modified form of my radiator having a
rectangular or flat casing one side of the latter having been removed.
In Figs. 8-9-10-11 and 12 of the drawings A designates the base of the
radiator, which may be of any convenient ornamental form, preferably circular in
general outline; and B designates a cylindrical casing upright thereon. The top B'
of this casing slopes inward and upward preferably with a neat curvature, leaving a
central opening B2 as a draft outlet. This top is imperforated except said draft
opening B2; but the cylindrical body of said casing is provided with a great number
of perforations b, allowing the free passage of air through it everywhere. For this
body of the casing any other form of openwork may be employed, such as braided
strips or stout wire and the material may be either metallic or non-metallic insulating
or non-insulating.
On said base A a small cylinder C concentric with and inside of casing B is
erected, the same constituting at once a draft flue and a frame for the heating wire.
The upper part C of this flue C is solid for perhaps a third, more or less, of the
entire length.
From this ring several strips c extended downward to a wire ring which forms
the base of the said cylindrical flue or frame. A network (3 of braided wire covers
these strips from the solid part C₁ of said cylinder to the base ring C² thereof.
This solid part C₁ the base ring C and the strips care provided with outwardly
extending studs c¹ or equivalent fastenings or supports on which the heating wire is
wound.
This wire marked D forms part of an electric circuit and is either insulated
throughout or separated by insulating material from all metallic parts of the radiator,
the various crossing parts of said heating wire, if it is so wound as to cross, being
also insulated from each other. The said wire is a continuous conductor, but wound
either as a spiral as shown or back and forth in obliquely crossing lines so as to

page_text: constitute an open wire cylinder or network enclosing the open part of frame C. The
length of wire thus wound ensures a considerable amount of resistance and a
corresponding degree of heat, so that the air passing through the radiator will be
warmed effectually when the electric current is at its maximum. The heat may of
course be regulated by decreasing and increasing the current as required. The air
passes in from all sides through perforations of the outer casing into contact with
the electric heating wire D and through interstices in the same, thence through the
wire network C3 of the inner cylindrical frame C to the interior of the latter and
finally out through the outlet opening 132 in the top of the casing B. On the drawings
arrows indicate the course thus taken.
The cylindrical form is decidedly the best for radiators of this kind, but of course
other forms may be used without departing from my invention. Thus in Fig. 12 the
casing B may be rectangular and provided with inwardly extending studs or pins
similar to those already described, or equivalent devices in its top, bottom, end and
sides, or some if not all of these inner faces or instead of a casing there may be
merely a frame as in the right hand part of said figure. The heating wire D is
passed from one to another of these studs in crossing lines, forming a network. The
same precautions against short circuiting are taken, the heating wire being either
coated throughout with insulating material or separated by this from all metallic parts
and from contact, with itself at all points where such contact may occur.
This form
of radiator may be used without a base. Indeed a base is not indispensable to any
form, though very desirable and convenient. When used it is preferably provided
with small openings e as shown in Figures 9 & 10 allowing the ends of heating wire D
to extend down through it.
The third part of my invention relates to a modification of the electric flat iron
hereinbefore described and consists mainly in a wire forming part of an electric
circuit and wound on a core said wire and core being inserted in and removable from
a hollow flat iron the upper part of which is lined interiorly with asbestos or equiva-
lent material, the bottom being lined on the inside with copper. In the accompanying
drawings Figure 13 represents a side elevation partly broken away.
Figure 14 a vertical cross section of a flat iron embodying my invention.
Figure 15 is an end view of the flat iron shell.
In Figs. 13 and 14 A designates the hollow shell of the flat iron having a handle a
and open at the rear to receive the wire B. This wire is wound about a core I which
may be hollow or solid, metallic or non-metallic.
The coils or rings of the wire are insulated from each other by strips J and from
the copper lining plate L below said wire by strips K.
A lining M of asbestos or other insulating material covers the inner face of the
hollow iron and may be attached to said copper lining plate L, so that the two
together will form a casing for the wire B and be removable therewith. Or they
may be attached to said hollow flat iron.
In either case the wire and its core are easily removed and replaced, and when in
position within said iron the ends of said wire make contact with the circuit wires 0 0',
by means of clamping posts N N or in any other suitable manner.
The beat generated in the space surrounding the wire B will readily be conducted
by the copper plate L to the bottom of the shell A and made thereby available in
ironing. Other material of suitable nature may be substituted for the wire and the
wire need not be in a coil. The plate L is not necessarily of copper although that
material is preferred.
The upper part of the flat iron is covered with a jacket P of asbestos or other
heat insulating material to prevent the radiation of the heat into the air.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is
1st. In an electric cooking or heating device, an interior layer of insulating material,

page_text: wire wound thereon and an exterior layer of insulating material enclosing all the metal
parts of the device substantially as set forth.
2nd. In an electric heater an exterior layer of insulating material, an interior
layer of insulating material concentric therewith and an interposed coil of wire, the
ends of said insulating material layers, being connected by strips or rings and the
wire forming part of an electric circuit substantially as set forth.
:
3rd. In an electric heater a wire forming part of an electric circuit and wound in
layers properly separated from each other to prevent short circuiting, in combination
with two concentric walls or layers of insulating material one of the latter being
within these layers of wire and the other beiug outside of them, and all the
metal parts of the device being enclosed within said exterior layer substantially as
set forth.
4th. A cylindrical heating device consisting of coils of wire Carranged in layers,
which are separated to prevent short circuiting in combination with a cylindrical
layer B of insulating material about which said wires are wound and a cylindrical
exterior layer A of insulating material enclosing all the metal parts of the device, the
said wires being in an electric circuit and the whole constituting an electric heating
cylinder substantially as set forth.
5th. An electric radiator having its heating wire in the form of openwork but
constituting a continuous conductor in an electric circuit and insulated wholly or
whenever necessary to avoid short circuiting. Said radiator being provided with
inlet and outlet draft openings permitting the passage of air through said wire
openwork substantially as set forth.
6th. In combination with an inner open frame, an electric conductor wound
thereon and forming part of an electric circuit both of said parts allowing the
passage of air through them for the purpose set forth.
7th. In combination with an inner open frame, a wire network surrounding the
same and insulated to guard against short circuiting the wire of said openwork
forming part of an electric circuit as one continuous conductor and allowing the free
passage of air through it substantially as set forth.
8th. In combination with a perforated exterior casing and an inner open frame
an interposed continuous conductor forming an open spiral or network which will
allow the passage of air, said conductor being in an electric circuit and insulated
against short circuiting substantially as set forth.
9th. The exterior casing B having perforations and outlet opening B² in combi-
nation with an interior frame C and an interposed spiral or network of wire consti-
tuting a continuous conductor in an electric circuit, said network casing and frame
allowing the air to pass freely from said perforations to said outlet through the
radiator substantially as set forth.
10th. The interior flue or frame C consisting of a solid upper part, a base
ring, strips connecting them and a wire spiral or netting on said strips and
provided externally with studs c¹ in combination with a heating wire wound over
said studs and around said frame and forming a network which allows the passage
of air, but constituting a continuous conductor in an electric circuit and insulated
against short circuiting substantially as set forth.
11th. An electric radiator having its heating wire wound to form spiral or other
openwork and enclosed within a casing said radiator being provided with studs or
equivalent fastenings for supporting said wire at its angles and holding it in position,
said wire constituting an open network which allows the free passage of air through
it though being a continuous conductor in an electric circuit and insulated against
short circuiting substantially as set forth.
12th. The combination of base A with casing B, frame C and wire network 1
arranged concentrically thereon, said parts B, C, D, allowing the passage of air
freely through them and the said network constituting a properly insulated continuous
conductor in an electric circuit for the purpose set forth.
13th. A.hollow flat iron provided with a removable wire coil having a core and
adapted to form part of an electric circuit substantially as set forth.

page_text: 14th. A hollow flat iron provided with a lining partly of non-heat conducting
material and partly of heat conducting material, and having a conductor of electricity
in the space within said lining said conductor being arranged to be in an electric
circuit when desired for the purpose set forth.
15th. In combination with a hollow flat iron a removable casing having an electric
conductor within it said conductor being arranged to be in an electric circuit when
desired substantially as set forth.
16th. A hollow flat iron having a copper plate in contact with the inner face of its
bottom and a suitably insulated electrical conductor in the space above said plate
said conductor being adapted to be made part of an electric circuit when desired for
the purpose set forth.
Dated this 31st day of December 1880
HENRY RICE BUTTERFIELD.
WILLIS MITCHELL.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicants.