Improvements in or relating to Apparatus for Controlling Electric Currents of High Tension and Great Quantity
Year: 1898

page_text: Date of Application, 16th June, 1898-Accepted, 20th Aug., 1898
COMPLETE SPECIFICATION.
Improvements in or relating to Apparatus for Controlling Electric
Currents of High Tension and Great Quantity.
I, EDWARD HIBBERD JOINSON, Electrician, and ROBERT LUNDELL, Electrician,
both of No. 527, West 34th Street, in the County of New York and State of New
York, 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:-
These improvements are directed particularly to apparatus for use in connection
with electric motors, dynamo electric machines or analogous electric translating
devices which utilize electrical currents of 'high potential and large quantity and
its objects are,
First, to provide means whereby arcing at the circuit controlling contacts 'may
be effectually avoided while the various circuit changes are being effected by the
controller in connecting up the circuits in any prearranged order for which the
translating device such as a motor may be devised; and, second, to provide means
whereby arcing at the circuit breaker itself is 'reduced to a minimum.
The improvements will be fully understood by referring to the accompanying
drawings, in which,
Figure 1 illustrates' diagrammatically a controller for an electric motor having
a starting coil, two field magnet coils, two armature coils, a drum carrying circuit
changing contacts, and the improved means for automatically interrupting the
circuit before certain current changes are effected in the motor circuits as the
controller drum is rotated in either direction.
Figure 2 is a longitudinal section taken through the improved automatic
circuit breaker illustrating the controlling magnet therefor, its plunger, the
arc extinguishing means and the switching contacts;
Figure 3 is a plan thereof; and
Figure 4 is a detail view of one of the spring supported contacts of the automatic
circuit breaker.
Referring first to Figure 1,
A represents a developed controller drum having a number of circuit controlling
contact strips s to s' inclusive arranged thereon for effecting the proper current
changes in any prearranged order through a starting resistance R, field magnet
coils F F and armatures A¹ and A2, a series of binding posts being provided with
contact brushes, not 'shown, but adapted to bear upon the strips s to s' inclusive
as the controller drum is rotated. c¹ and care controller contacts located as
shown near the upper end of the drum or cylinder A, c¹ being slightly in advance
of contact strips s s₁ and s³, and c² being of greater width than c¹ for a purpose
'to be hereinafter described.
Brushes, not shown, are also provided for the binding posts c and adapted
to bear on the contacts and as said contacts pass under the free ends thereof.

page_text: 00, 1–1 2–2, 3–3, 4–4 and 5-5 are broken lines illustrating the different
positions of the controller drum and the circuit relations which the field and
armature coils assume for said positions.
Referring now to Figures 2, 3 and 4, C represents a rectangular iron casing
with an approximately cylindrical base provided with means for securing it in
a position adjacent to the controller. M is a solenoid coil of comparatively small
dimensions, it being only used momentarily when the current changes are being
effected by the controller and hence having ample time to cool off. One end
of this coil is connected by a conductor w2 (Figure 1) to binding post c and the other
by a second conductor w³ running to the negative binding post of the controller.
P¹ is a brass tube secured in the casing C and provided at its upper end with an
air tight head having air vents or tubes a a¹. P is an iron plunger or solenoid
core fitting snugly within the tube P1 and r is a steel rod secured thereto and
fitting snugly in the head of the tube. To the upper end of the rod r is secured
a copper circuit breaking plate B but insulated therefrom by washers i, said
plate resting normally on a number of pairs of carbon and copper contact
blocks c³¹³ ³ c6 6, etc., supported yieldingly on conducting springs t t which
in turn are connected to binding posts I D¹ supported by insulating material J J¹
secured to the top of the casing C.
Referring again to Figure 1, suppose the controller to be on open circuit with
the contact springs free from contact with the contact strips on the cylinder or
drum A, as shown by the dotted line 0-0. Upon rotating the controller cylinder
from the position indicated by line 0-0 to position 1-1 the operation is as
follows:-
Owing to the advanced position of contact strip c¹ the upper contact brushes first
close a circuit through the shunt coil M of the circuit breaker, causing the contact
plate B to suddenly break connection between the carbon and copper contacts c³
and c. Upon a further rotation of the cylinder the lower contact springs
or brushes establish connection between the various field coils and armatures
in the manner indicated at line 1-1 and when position 1-1 is finally reached
the circuit through the shunt coil M is broken and the circuit breaker has again
closed connection between the contact blocks ccc and c6, causing the line
current to flow as indicated at line 1-1.
When the cylinder is rotated from position 1-1 to 2-2 the starting resistance
is merely cut out and when position 3-3 is reached the field coils F1 and F2
are coupled in parallel. Continuing the rotation of the controller cylinder to
position 44, the circuit breaker is again brought into action and is caused by
contact strip to break the line current before the contact springs or brushes
are disconnected from the contact strips s, 1 and 3 and to keep the line current
broken until position 4-4 is reached. Position 5-5 will be reached without
any action of the circuit breaker. Upon reversing the controller cylinder from
position 5-5 the operation is substantially the same. The circuit breaker will
interrupt the line current before the contact springs are disconnected from con-
tact strips s4, 5, 6 and s' and will keep the line current interrupted until position 3-3
is reached. The circuit breaker is again brought into action before the
contact springs have become disconnected from the contact strips s s¹ and s²,
thus breaking the line current at contact blocks c3 c5 and C6.
Referring now to Figure 2 of the drawings for a clear understanding of the
operation of the arc extinguishing means, by which any arc at the switch break-
ing contacts is extinguished, it will be apparent that when the shunt coil M is
energized, the plunger P is drawn suddenly upward so that the circuit breaking
plate B interrupts the circuit by being first lifted from the spring supported
copper contact blocks c5c5 and 6 c6 and afterwards from the carbon contact
blocks c3 c4. At the same instant blasts of air are ejected from the tube P¹ above
the head of plunger P through the air-vents a al with such force and volume as
to suddenly blow out or extinguish any arc which might result at the last points
of rupture.

page_text: Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:
1. A normally closed electromagnetic circuit breaker, in combination with a
current changing device and a translating device, such as an electric motor, said
circuit breaker being arranged to momentarily interrupt the current supply for
the purpose of preventing arcing at the current changing device, substantially
as described.
2. A circuit breaker consisting of electromagnetic means for interrupting an
electric circuit, in combination with means controlled by the movable part of the
circuit breaker and adapted to force or eject a blast of air around the circuit.
breaking contacts thereof, substantially as described.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.