Improved Methods of and Means for Making and Breaking Electric Circuits.
Year: 1895

page_text: Date of Application, 18th Sent., 1895
Complete Specification Left, 14th July, 1896 -Accepted, 22nd Aug., 1996
PROVISIONAL SPECIFICATION.
Improved Methods of and Means for Making and Breaking Electric
Circuits.
1, REGINALD BELFIELD, of 32, Victoria Street, in the City of Westminster,
Electrician, do hereby declare the nature of this invention to be as follows:-
My invention relates to improved methods of and means for making and breaking
electric circuits.
The objects of my said invention are to provide for making and breaking an
electric circuit or circuits automatically when the current in another circuit
becomes greater or less than a certain predetermined value and also to provide for
making and breaking an electric circuit or circuits from a place at a distance from
the said circuit.
An important feature of my invention consists in the employment of an electric
motor or equivalent magnetic device for actuating the switch contact, the circuit
of said motor or its equivalent being made or broken by means of an electromagnet
in the circuit in which the current varies. A further important feature of my
invention consists in the provision of means whereby when the switch has been
operated by the motor or its equivalent the motor circuit is automatically broken
until such time as it is again required to operate the switch.
In order that the nature of my invention may be more clearly understood I will
now proceed to describe briefly how it may be carried out in practice.
The circuit in which the current varies which I will call the principal circuit
has included in it an electromagnet having a movable armature controlled by a
spring or weight. The said armature is arranged to "make" the motor circuit
when moved from its normal position, that is to say when the current in the
principal circuit falls either above or below a predetermined value. The motor is
thereby caused to rotate and through suitable mechanism operates the switch in
another circuit which I will call the auxiliary circuit. At the same time the
mechanism restores the armature of the electromagnet to its normal position
breaking the motor circuit as soon as the switch has been operated. The armature
of the electromagnet is so connected with the switch mechanism that the armature
can only move towards its magnet when the switch of the auxiliary circuit is open.
When the said switch is closed the armature can only move away from its magnet
that is to say under these conditions it only operates to make the motor circuit
when the current in the principal circuit diminishes. Two or more switches
controlling two or more auxiliary circuits may be simultaneously operated by the
mechanism if desired.
The effect of opening or closing the auxiliary circuit is to connect or disconnect
another source of energy to or from the principal circuit thus bringing the current
flowing therein nearer its normal value.
I interpose a spring or its equivalent between the motor and the switch
mechanism in such a manner so that the motor does not directly operate the
switch but winds up the spring which ultimately escapes operating the switch.
I use the term motor to include any electromagnetic mechanism which will as
long as current is supplied to it continue to operate to wind up a spring or its
equivalent.
When I desire to operate switches from a distance, for example, when it is
required to control from a central station transformers at one or more sub-stations

page_text: I provide in the primary circuit of each transformer an electromagnet which is
energized by the leakage current through the primary coil when the circuit is
closed at the central station. The electromagnet then operates a switch in the
manner herein before described thereby connecting the secondary coils of the
transformer to the feeding mains.
In a modification the electromagnets at the sub-stations are included in a
separate circuit or circuits which can be opened or closed at the central station
independently of the main or feeder circuit."
Dated this 18th day of September 1895.
W. P. THOMPSON & Co.,
31, High Holborn, London, W.C., Patent Agents for the Applicant.
Improved Methods of and Means for Making and Breaking Electric
Circuits.
I REGINALD BELFIELD, of 32 Victoria Street, in the City of Westminster,
Electrician 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 improved methods of and means for making and breaking
electric circuits.
The objects of my said invention are to provide for making and breaking an
electric circuit or circuits automatically when the current in another circuit
becomes greater or less than a certain predetermined value and also to provide for
making and breaking an electric circuit or circuits from a place at a distance from
the said circuit.
An important feature of my invention consists in the employment of an electric
motor or equivalent magnetic device for actuating the switch contacts, the circuit
of said motor or its equivalent being made or broken by means of an electromagnet
in the circuit in which the current varies. A further important feature of my
invention consists in the provision of means whereby when the switch has been
operated by the motor or its equivalent the motor circuit is automatically broken
until such time as it is again required to operate the switch...
In order that my invention may be clearly understood I will now proceed to
describe the same with reference to the accompanying drawings, in which,
Figure 1 is a side elevation of my apparatus with the switch in open position.
Figure 2 is a plan view of the same with the switch, in a closed position
together with a diagram of circuits and translating devices to which it is
applicable.
Figures 3 and are diagrams of circuits showing further applications of the
invention.
Reference being now had to the drawings in detail, 1 is a suitable base which
supports bearing blocks or standards 2 for a shaft 3, on which are rigidly mounted
two pairs of movable contact arms 4 and 5, each pair being suitably insulated from
the other pair.
Mounted upon the base 1 in such a position as to be engaged by
the arms 4 and 5 at certain points in their movement as the shaft rotates, are the
stationary contacts 6 and 7. Each of these contacts preferably comprises two
strips or leaves between which the movable contact arms engage as is usual in so
called knife switches. It will be understood that the number and relative
arrangement of the switch arms and stationary contacts as well as the form of each
will be varied in practice as may be found necessary or desirable.
Mounted rigidly upon the shaft 3 and near the end opposite to that carrying the

page_text: contact arms 4 and 5 is a stop lever 8, having a long arm 9 and a short arm 10, the
former being provided on one side at its outer end with a lug 11 in alignment with
the short arm, or, if preferred, the two arms may be in the same vertical plane and
each provided with a lug at its outer end, as will be readily understood. A worm
wheel 12 is loosely mounted upon the shaft 3 adjacent to that side of the stop
lever 8 which bears the lug 11, a connection between this worm wheel and the shaft
being made by means of a stiff coiled spring 13, one end of such spring being
attached to the shaft and the other to the worm wheel in such a manner that as the
wheel is rotated in the direction indicated by the arrow in Figure 1 and the shaft
is held stationary, the spring will be placed under such tension that it will cause
the shaft to rotate whenever the latter is released, as will be hereinafter more fully
described..
The worm wheel 12 is provided with a cam groove on the face adjacent to the
stop lever 8, the two main portions 14 and 15 of which have the form of ares of
circles, the radius of the former being somewhat greater than that of the latter.
These two arc-shaped portions of the grooves are connected at diametrically
opposite points. by spaces 16 and 16' of considerably greater width.
Pivoted to a suitable boss or projection on the base 1 is a stop lever 17, provided
with a pin 18 which engages with the cam groove in the worm wheel 12. This
stop 17 is so located with, reference to the stop lever 8 that one or the other of its
arms will normally engage with it and thus hold the shaft 3 against movement.
19 is a small electric motor supported by the base 1 and connected by means of
suitable gearing 20 with the worm shaft 21, the said shaft carrying the worm 22
which meshes with the worm wheel 12, and thus causes it to rotate as long as the
motor 19 is in operation. As this motor always runs in the same direction, the
worm wheel will also rotate in the same direction and tend to wind the spring 13.
The motor 19 may derive its current from any suitable source, but in the present
instance it is, shown as included in the circuit of a battery 23. The respective
terminals of this battery circuit are connected to contact points 24 and 24¹ on
the base of the machine. These contact points will be made of metal or carbon
as may be desired and each pair will be electrically connected.
25 represents a plurality of translating devices fed from the secondary circuit 26
of a transformer 27, the primary of such transformer being supplied with current
from a suitable generator circuit 28. Mounted upon the base 1, and preferably at
the end opposite to that carrying the motor 19, is an electromagnet 29, the coil or
coils of which, are included in the circuit 26. The armature 30 for the electro-
magnet 29 is supported by an arm 31 pivoted to suitable standards 32, only one of
which is shown in Figure 1. This arm 31 is provided at its outer end with a pin 33
which engages with the camn.groove in the worm wheel 12. Depending from the
arm 31 are one or more contact strips or springs 34, the lower ends of which
project respectively between the pairs of contact points 24 and 24'. This arm 31
is also preferably provided with an adjustable counterweight 35. The contacts 6
constitute the terminals of the circuit 36 of the primary of the transformer 37, and
the contacts 7 constitute the terininals of the secondary 36¹ of the transformer 37.
This secondary circuit is so connected that when the circuits are closed by
contacts 4, 6 and 5, 7 the current from the secondaries of both transformers will
traverse the coil of the electro-magnet 29 and the translating devices 25.
The mechanism herein before described may be very considerably modified by
anyone skilled in the art without departing from the spirit and scope of my
invention, as will be readily understood. For example, other means than a worm
gear inay be employed for rotating the wheel provided with the cam groove, aud
a plurality of cam grooves or wheels or both may be employed. The grooved
wheel may also be rigidly mounted upon its shaft and the releasing devices
attached to the motor mechanism so that the switch will be released after the
motor has done a certain amount of work. These and many other variations may
be adopted if found desirable.
Assuming that the several parts of the apparatus are in the position shown in

page_text: Figure 1, the operation is as follows:-The current from the secondary 26 of the
transformer 27 passing through the translating devices 25 will also traverse the
coil of the electro-magnet 29, and thus tend to attract the armature 30. As in
this position of the apparatus the pin 33 will be in the enlarged portion 16 of the
cam groove, the armature will be free to move. If the counterweight is so placed
as to exactly counteract the magnetic effect of a current just sufficient to supply
the translating devices in circuit, there will be no movement of the connected parts.
If, however, an additional number of translating devices be switched into the
circuit, thus causing an additional flow of current through the magnet coil, the
armature will be drawn downward and the other end carrying the pin 33 elevated,
thus bringing the contact springs 34 into engagement with the contact points 24'
at the right, thereby closing the circuit of the motor 19. This will start the motor,
which, by means of the gearing between the same and the worm wheel 12, will
cause the latter to rotate. When the wide portion 16' of the cam groove reaches
the pin 18, the stop 17 which now supports the short arm 10 of the stop lever 8
will be gradually pressed outward until the stop lever is released, when the
spring 13, which has been gradually placed under increased tension by the rotation
of the worm wheel will quickly reverse the stop lever, bringing the end of the
arm 9 into contact with the stop 17 and closing the switches 4, 6 and 5, 7 thus
closing the primary and secondary circuits of the transformer 37 and adding the
secondary current to that supplied to the translating devices by the transformer 27.
As the action just described takes place while the pin 33 engages the narrow
portion 15 of the cam groove, the contacts 24' and 34 will remain in engagement
and the motor 19 will be kept running until the wide portion 16' of the cam groove
reaches the said pin 33, when the latter will be pressed outward by the inner wall
of the groove until the contact is broken and the motor stopped, the parts being
then in the position shown in Figure 2. The shape of the cam is such that it will
cause armature 30 to be brought back approximately to the position it occupied
before the cycle of events above described occurred, and will prevent any move-
ment thereof in the direction of the magnet. The armature is free to move in the
opposite direction, however, whenever the counterweight 35 shall overcome the pull
of the magnet. A similar locking arrangement is effected by the wide portion 16
of the cam except that it is so shaped as to permit the armature 30 to move only
toward the magnet 29 as above described. A pin 49 is attached to the rotating
wheel 12, so that if by any means the switch arms 4 and 5 should stick between
the leaves so that the spring alone will not be able to move them, the pin will
come into contact with the arm 10 of the lever 8 and force the switch arms to
move.
When the switches 4, 6, and 5, 7 are closed and a sufficient number of translating
devices are cut out to materially decrease the demand for current, the counter-
balance weight will overcome the pull upon armature 50 by magnet 29, and the
contacts 34 and the points 24, opposite to those heretofore described as in engage-
ment will be brought into engagement, thus closing the motor circuit 19 and starting
the rotation of the worm wheel 12. As this rotation continues, the stop 17 will be
gradually moved inward until it clears the lug 11 on the end of the arm 9 of the
stop lever 8 as before described, and the spring will reverse said lever and thus
quickly open the switches 4, 6 and 5, 7, interrupting both the primary and secondary
circuits of the transformer 37.
I may employ any known auxiliary means for suppressing or extinguishing arcs
which may form or tend to form between these stationary and movable contacts
without departing from my invention, but such devices will probably be unnecessary
under most circumstances on account of the very rapid and wide separation of the
contacts.
The diagram of circuits illustrated in Figure 3 is intended to show the use of my
invention at substations for making and breaking the circuits of the secondaries of
the sub-station transformers in accordance with the manipulation of the switches in
the feeder circuits of the main station

page_text: In this figure 38 represents the main circuit fed by generators 39, and 40, 41
and 42, the feeder circuits extending between the main station and the trans--
formers 43, 44 and 45 at the sub-stations. 46 are the feeder switches for these
feeder circuits, and 47, the electromagnetic device herein before described, the coil
of which is included in the feeder circuit at each sub-station. The switching-
device described in connection with Figures 1 and 2 is here connected in the
secondary circuit of the transformer at each substation which supplies suitable-
translating devices 48. Assuming that the secondary circuits are open, if one of the
feeder switches 46 or any of them be closed, the leakage current through the corre--
sponding primary at the sub-station will energize the actuating coil of the electro-
magnet 47 sufficiently to start the switch motor which closes the secondary circuit.
It will also be apparent from the foregoing description that if the feeder switch be
opened the flow of current in the primary of the transformer at the corresponding
sub-station and also in the actuating coil 47, will cease, and the switch-operating
motor will be started and will open the secondary of the transformer. It will
therefore be readily understood that the transformers at the sub-stations are at all
times under the control, of the attendant at the main station and may be cut into
or out of circuit without the employment of any additional conductors other than
those employed for feeding the translating devices, and also without any attention.
at the sub-stations.
Referring to Figure 4, 38' is a generator circuit fed by generators 391, 40¹, 411,.
and 421 are the feeding mains for the primaries of transformers 43', 44 and 45
located at sub-stations, 48' being the work circuits fed by the secondaries of such
transformers. 50 is a second circuit fed by a battery or other source of current 51,
this circuit extends to all the substations and includes at each an electro-magnetic
device 29' like that hereinbefore described which controls a switch 52 in the primary
circuit of the transformer, these switches being like that heretofore described. It
will be understood that the opening or closing of the battery circuit at the main-
station will effect the cutting in or out of the primaries of all the transformers at
the sub-stations.
.
It will be apparent to anyone skilled in the art that a solenoid and core or other
equivalent device may be employed in lieu of an electromagnet and armature for
closing the motor circuit, but I prefer substantially the construction illustrated and
described for the reason that the strength of the magnetic field and therefore the
force exerted upon the armature is increased the nearer the armature is brought to
the poles of the magnet, thus surely and effectually attracting and holding the
armature in the position desired.
I desire to be understood not only that the form and arrangement of the several
parts may be widely varied without departing from the spirit and scope of my
invention, but that the apparatus, either in the form illustrated and described or in
a modified form may be utilised in other relations than those which have heretofore
been described. I do not, therefore, intend to limit my invention to any of the
details described except in so far as limitations may be imposed by the state of
the art.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. An automatic apparatus by means of which the strength of the current in one
circuit governs the flow of current in another circuit, comprising a switch, a motor
for operating the same controlled by an electromagnetic device in the governing
circuit, substantially as described.
2. In an automatic apparatus such as described the provision of means whereby
after the switch has been operated the movable portion of the electromagnetic
device is caused to assume its normal position.
3. In apparatus such as described connecting the switch with the governing
device so that when the switch is closed the mechanism can only cause the motor t

page_text: operate to open the switch and when the switch is open the mechanism can only
cause the motor to close the switch.
4. In apparatus such as described means for ensuring that the motor circuit shall
be not be broken until after the switch has been operated by the motor, substantially
as described.
5. The method of closing the secondary circuit of a transformer which consists
in actuating the circuit closing switch by means of the magnetising current through
the primary of said transformer.
6. An automatic apparatus constructed and operating substantially as described
with reference to Figure 1 of the accompanying drawings.
6. In a system of electrical distribution the means for opening or closing a circuit
at a given point by a switch or switches at another point substantially as described
with reference to Figure 3 or to Figure 4 of the accompanying drawings.
Dated this 14th day of July 1896.
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicant.