Device or Circuit Connection for Electric Heating Bodies and analogous Electrical Appliances.
Year: 1893

page_text: Date of Application, 10th Nov., 1893
Complete Specification Left, 27th Aug., 1894-Accepted, 29th Sept., 1894
PROVISIONAL SPECIFICATION.
Contact Device or Circuit Connection for Electric Heating Bodies
and analogous Electrical Appliances.
I, FRIEDRICH WILHELM SCHINDLER, Manufacturer, of Kennelbach, near
Bregenz, in the Austro-Hungarian Empire, do hereby declare the nature of this
invention to be as follows:-
My invention relates to electric heating bodies provided with two or more
(electrically) parallel electric heating circuits, and has for its object, to provide
simple and convenient means for connecting at will one or more of the said circuits
with the electric supply system or other source of electrical energy, in order to
regulate the heating effect, as may be required.
For this purpose I employ a three pole plug contact device consisting of two
principal parts, one of which carries three parallel plugs or contact pins, while the
other contains three corresponding sockets lined with metal bushes. One of the
two parts, that is, either the plug piece or the socket piece, is electrically connected
with the source of electricity, while the other part is electrically connected with
the heating body.
The three parallel contact pins are preferably placed in a row on the same plane
at equal distances apart, instead of which they may, however, form the corners of
an equilateral triangle, the three sockets being always arranged in a corresponding
manner.
In the following description I will suppose, that the plug piece is permanently
fixed to the heating apparatus and that the axes of the plugs are in the same plane,
while the socket piece is moveable and attached to the ends of two conducting
wires which connect it with the electric supply system. In this case one of the
two conducting wires, for instance the positive wire, is connected with the first and
the third socket (positive poles) while the other conducting wire (the negative
wire) is connected with the second or intermediate socket (negative pole). In the
plug piece, the second or intermediate plug forms one common pole or outgoing
terminal for the two or more electric heating circuits contained in the heating
body, while the first and third plug or contact pin form the opposite poles or the
ingoing terminals of the said electrically_parallel heating circuits.
By means of this arrangement the heating current supplied through the two
supply wires may be distributed in three ways, that is to say, either to the first
eating circuit, or the first group of heating circuits, or to the second heating
circuit or group of circuits, or to both circuits at the same time. For the first or
econd method of distribution, the intermediate contact plug is introduced into the
irst or third socket, and one of the outer contact plugs into the intermediate
ocket; for the third method, the three contact plugs are introduced into the three
ockets at the same time. If, for instance, the heating body contains two parallel
eating circuits, of which at the available pressure the first gives one heat unit,
nd the second two heat units, the body may be heated either with one unit, or
ith two or three heat units.
If there are three electrically parallel heating circuits, one of the outer contact
ins (the first pin) serves as a terminal for two of the circuits, while the third pin
rves as a corresponding terminal for the third circuit, and the second or
termediate contact pin is the opposite terminal for the three circuits.
Dated this 10th day of November 1893.

page_text: Contact Device or Circuit Connection for Electric Heating Bodies:
and analogous Electrical Appliances.
I, FRIEDRICH WILHELM SCHINDLER, Manufacturer, of Kennelbach, near
Bregenz, in the Austro-Hungarian 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 :-
My invention relates to electric heating bodies provided with two or more
(electrically) parallel heating wires or circuits, and has for its object, to provide a
simple and convenient means for connecting at will one or more of the said wires
or circuits with the electric supply system or other source of electrical energy, in
order to regulate the heating effect as may be required.
For this purpose, I employ a three-pole plug contact device consisting of two
principal parts, one of which carries three parallel plugs or contact pins, while the
other contains three corresponding sockets lined with metal bushes. One of the
two parts, that is, either the plug piece or the socket piece, is electrically connected
with the source of electricity, while the other part is electrically connected with
the heating body.
In the following description, reférence will be made to the accompanying
diagrams, of which Figs. 1 to 3 represent a three-pole contact device in three
different positions or stages, while Figs. 4 and 5 indicate an application of the
same and Figs. 6 to 10 diagrams of a four-pole plug contact in different positions.
A is a socket piece connected with the ingoing and the outgoing wire (that is the
positive and the negative conductor) in such a manner, that the conductor for the
outgoing current is in electric connection with the intermediate contact or socket a,
while the conductor for the ingoing current has two branches, which establish
electric connection with the two lateral contacts or sockets b and c.
In accordance with the bifurcation of the ingoing supply wire, the heating
body B contains two conductors or two groups of conductors and Y, which start
jointly from the intermediate contact or plug d and terminate separately in the two
lateral contacts or plugs e f. In this manner three different heating effects or
current distributions may be obtained, corresponding to the positions represented
by Figs. 1, 2 and 3.
In Fig. 1, the movable socket piece A is placed so, as to bring the contacts a
and together with the contacts c and d.
In Fig. 2, the piece A is placed so as to bring the contacts a and b together with
the contacts d and f.
In Fig. 3 the piece A has an intermediate position, so as to bring all three
contacts a, b, c, together with the contacts c, d, and f..
Supposing, that with the method of connection represented by Fig. 1 the
conductor embedded in the heating body B supplies one unit of heat, and that in
the case represented by Fig. 2 the conductor y supplies two units of heat, then
Fig. 3 represents the position, where the conductors x and y together supply
1+2 3 units of heat.
It is evident, therefore, that, by placing the movable contact piece A either in
the position of Fig. 1, or of Fig. 2 or of Fig. 3, I may supply or utilize at will
either one, or two or three units of heat.
Instead of interposing one heating wire between the contacts c and d or between
the contacts d and f, I may use two or more between each pair of contacts.
One of each pair of contacts is preferably a split pin fitting into a cylindrical
metal bush by spring action, but other forms of interchangeable or shifting contacts
may be adopted, without departing from my invention, for instance saddle pieces

page_text: or wedge-pieces, as will be easily understood. Although I prefer to arrange the-
contacts in a straight line, they may be arranged in a triangle.
Figs. 4 and 5 represent an electric frying pan provided with my three pole-
contact devices, as an example of the great number of applications of my invention.
In this case, three heating wires C are embedded in a shallow layer or plate D
of refractory material, so as to form three parallel circuits. This heating plate or
layer is placed in a casing A which fits like a cap to the bottom of the frying pan,
so as to enclose the lower part of the same and produce a direct contact between
the said heating plate and the bottom of the pan.
The three contact pins or plugs B are fixed to a small box E attached to the
circumference of the casing A. The conducting wires. C pass from the contact
plugs B to the heating plate D through perforations of the casing A and box E
and are insulated from the same. The connection between the plugs B and the
supply wires G is formed by a detachable contact piece F containing three metallic
sockets or contact sleeves insulated from each other but connected with the two
supply wires G in the manner represented by Fig. 1.
This arrangement may, of course, be reversed by fixing the socket piece to the
box E and the plug piece to the supply wires G.
In the four-pole plug contact device represented by Figs. 6 to 10, I is the
common starting point for the three heating wires or groups of heating wires I-a,.
Ib, I-c, and is electrically connected with the plug 1, for instance by a thick
wire as indicated by a dotted line. The movable socket piece has four sockets,.
one of which is connected with one of the supply wires, (negative pole), while the
three other sockets are connected with the other supply wire, (positive pole).
If the movable contact piece is applied to the fixed contacts in the manner
represented by Fig. 6, the current enters at a, and passes through the first heating
wire to I, and thence returns through the second heating wire to b. The two
heating wires are therefore arranged and heated in series.
If the movable contact is applied as indicated by Fig. 7, the current passes.
from I directly to I and thence through the heating wire I-b. The wire I-a
remains inactive, because it has the same polarity as I-I.
In the position represented by Fig. 8, the current flows from I to I and thence
simultaneously through the three heating wires I-a, I-b, I-c, causing them to
glow.
In the position indicated by Fig. 10, no heating effect is produced, because the
two plugs I and c have the same polarity. Consequently, the movable contact
piece should never be placed in this position.
The apparatus may be arranged in such a manner, that under normal conditions,
the wire a represents one unit of heat or receives one unit of current (1 ampère),.
the wire -b one unit, and the wire I-c two units. Instead of being arranged in.
a straight line, the four poles may form a quadrilateral.
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. A three-pole contact device for electric heaters and analogous appliances,.
comprising in its construction a movable contact piece having three contacts or
electric terminals, one of which is connected with the first supply wire or conductor,
while the others are connected with the second supply wire or conductor, and three
stationary contacts or terminals connected with the heating wires, one of the said
contacts or terminals, (the intermediate one) serving as common starting point for
the (electrically parallel) heating wires, while the others are separately connected
with the opposite ends of the said wires or groups of wires, the whole being
arranged and adapted to operate substantially as described and for the purpose-
specified.
2. A multiple plug contact device for electric heaters, comprising a movable.
contact piece A attached to the supply wires and containing three contacts or

page_text: verunuals a, b, c, one of which is connected with the first supply wire, while the
others are connected with the other supply wire, and an electric heating body B
having three or more heating wires xy and three terminals or stationary
contacts e df, the terminal d serving as a common starting point for the heating
wires, while the terminals e and fare connected with the opposite ends of the same,
so that either or each of the said contacts ef, serves as terminal for two or more
heating wires, y, the whole being arranged and adapted to operate substantially
as described with reference to Figs. 1 to 3.
3. A multiple plug contact device for electric heaters and analogous appliances,
consisting of a movable and a stationary contact piece, each of which has four or
more poles arranged and adapted to operate substantially as described.
Dated this 25th day of August 1894.
FAIRFAX & WETTER,
433, Strand, London, Agents.