Improved Means for Producing and Applying Induced Electric Currents for Heating and other Purposes.
Year: 1893

page_text: Date of Application, 28th Mar., 1893-Accepted, 23rd Sept., 1893
COMPLETE SPECIFICATION.
Improved Means for Producing and Applying Induced Electric
Currents for Heating and other Purposes.
I, SAMUEL B. JENKINS, Electrician of Boston, in the County of Suffolk, and
State of Massachusetts United States of North America do hereby declare the
nature of my invention and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement :-
The primary object of this invention is to utilize for practical purposes the reversed
induced current which is set up in a conductor when the primary current is
interrupted; the said conductor being wound on a magnetic core and a second
conductor being wound on the same core reversely with respect to its length for
the passage of a second current of electricity continuously in an opposite direction
from end to end of the core in order to prevent sparking when the circuit of the
first current is thus broken. At each breaking of the current a certain evolution
of heat will take place, in excess of the normal heat of resistance, and probably
due to induction.
A chief feature of the present invention consists in a method and means hereinafter
set forth of utilizing this heat in a heating system for buildings.
But the induced current above described may be applied to many other uses, the
same series of conductors and currents being in substance adopted. The said
induced current is well suited to such applications, being of relatively high electro-
motive force, though less in volume than the primary current which creates it.
My said invention then consists in a system of electrical distribution for attaining
these ends and a method and means of electric heating whereby it is applied to one
especial practical use; all substantially as hereinafter more particularly set forth
and claimed.
In the accompanying drawings
Figure 1 represents the cores coils conductors, commutator and motor of one
combination of devices embodying my invention; and
Figure 2 represents the same parts in a second combination or arrangement.
These views are taken partly in perspective, partly diagrammatic.
The form shown in Figure 1 makes the intermittent circuit through each heater
separately, that shown in Figure 2 makes it through all the heating coils collectively.
A and B designate respectively the magnetic cores of which only two are shown,
although they may be of any number. C. designates a commutator D the motor
which rotates it E the common shaft of these two parts, E¹ their bed plate
and E' their supporting standards and bearings. The commutator may consist as
shown of a disk having alternating insulated and conducting segments and a
projecting conducting cylinder C¹. The motor may be of any known construction
suitable to rotate the said commutator or to oscillate it.
F. and G designate two wires which extend to a source of electricity completing
the circuits. From wire F a short wire d extends to a binding post d' of the motor
and from the wire G a short wire g extends to the binding post d² of the motor.
Whether the circuit through the commutator is interrupted or not the circuit
through the motor is operative following these wires dg and their necessary
connections as indicated by the arrows.
The wire F is connected to a branch wire F' which extends to the upper end of
core A and winds down on it as shown from left to right forming a helix F2 from
which a wire F³, preferably integral therewith, extends to the wire G. In like
manner the branch wire f extends from wire F winds down on core B forming
helix and returns as wire f³ to the wire G. The winding for each helix is

page_text: much closer than that shown and suitably insulated. This applies also to the
helices yet to be described. There is a similar winding for each core and a
continuous current flows through all dividing between the branches in proportion
to their resistances as usual. Preferably this is nearly equal in each instance.
I, J and K (Figure 1) designate three contact plates, springs or brushes mounted
on an insulating part or attachment e¹ of the said base E¹, and provided with
binding screws ijk. The two former brushes bear on the periphery of the disk
part of the commutator at points some distance apart. The brush K bears against
the drum or cylindrical extension C₁ of the same.
From the binding post i of brush or contact spring I a wire G extends to the
lower end of the core and winds up the latter from left to right in a
spiral line
parallel with helix or coil F2 forming a similar helix or coil G." Thence it returns
as wire G³ to wire G. In like manner wire gl from brush J runs to and around
core B forming helix g² and returns as wire g³ to wire G. A wire f extends from
binding post k of contact spring or brush K to wire F.
When the commutator is in the position of rotation indicated by Figure 1, the
circuit, as shown by the arrows, will be from wire F through wire f, brush K
extension C¹ commutator. C brush I wire G helix G2 and wire G³ to wire Ģ and
the source of electricity. If the commutator be turned far enough to bring the
brush J into contact with a conducting segment of the disk of the commutator and
leave the brush I against an insulating segment of the latter the circuit is as before
except that wire 9 helix 92 and wire 93 are substituted for the corresponding
conductors before mentioned. In either case the current is in.the reverse direction
with respect to the ends of the core from that of the continuous current first
described. The rotation or oscillation of the commutator by the motor causes a
rapid making and breaking of circuits successively bringing each coil or helix
controlled thereby into the electrical circuit. As often as the current is interrupted
in shifting to another helix an induced current is created in the same wire but in
the reverse direction and as a consequence heat is evolved beyond the heat of wire
resistance. This heat becomes available for heating the rooms or other places in
which the cores are respectively situated. Thus each core with its appurtenances
becomes an electro-magnetic heater operating in accordance with the principle
above stated.
This is equally true of the construction and arrangement shown in Figure 2
which differs from Figure 1 only in connecting the wire G¹ to the wire g' and the
latter to the brush or contact spring I, the brush J being dispensed with. When
the commutator in the position as shown in Figure 2, for the brush I to bear against
one of the insulated parts or segments of it the circuit is broken though the said
commutator and both of the coils or helices G² 92, and there is a circuit through
the motor only and a circuit through the coils F2 f2. When the action of the
latter has turned the said commutator far enough for one of the conducting segments
thereof to be in contact with the said brush I the circuit is closed through both of
these coils simultaneously or as many of them as there may be. Thus there is a
rapidly interrupted current set up through all the coils G² ² &c. of the series and
consequently a reversed induced current is created through the same.
continuous current through the helices F2 2 in the opposite direction with respect
to the length of the cores A B, prevents sparking in the interrupted circuit as
before explained.
The
Many other arrangements for connecting the several heaters in circuit with the
commutator or some equivalent device may be adopted, those shown and described
herein being intended merely to present two very convenient ones intending
respectively to switch the current from coil to coil never passing it through more
than one coil or helix at a time and to admit it to, or cut it off from, the entire
series simultaneously.
Of course the induced current thus set up may be applied to other than heating
purposes.

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what I
claim is:
First. A series of cores arranged individually at the points where an induced
current and its results are needed, in combination with a series of coils or helices
wound thereon and forming part of a circuit for a continuous current, a second
series of coils or helices wound on the same cores and forming part of the circuit
for an interrupted current, mechanism for automatically interrupting the latter
current either for the individual coils in succession or for the series taken together
in order to create an induced current substantially as set forth.
Second. The method of generating heat by electricity and applying the same to
a heating system for various points or apartments consisting in sending a
continuous current and an intermittent current in opposite directions with respect
to the length of the cores on which they are wound, the interruption of the latter
current generating a reversed induced current and producing heat thereby while
the continuous current first mentioned prevents sparking at such interruptions
substantially as set forth.
Third. A motor and commutator in combination with a series of magnetic cores, two
series of coils or helices wound thereon, conductors for making circuit for a
continuous current through the first series of helices and conductors and contact
pieces for making intermittent circuit through the helices of the second series
individually or collectively by means of the said commutator, the two currents
entering at opposite ends of said helices substantially as set forth.
1000
Signed in the presence of
ALMON C. THOMPSON,
EDWIN W. PIERCE.
SAMUEL B. JENKINS.