Improvements in Automatic Safety Devices for Electric Circuits.
Year: 1895

page_text: Date of Application, 2nd July, 1895-Accepted, 10th Aug., 1895
COMPLETE SPECIFICATION.
Improvements in Automatic Safety Devices for Electric Circuits.
I, LEWIS G. ROWAND, of 13 North Fourth Street, Camden, in the County of
Camden, State of New Jersey, United States of America, 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 consists essentially in placing upon an electric circuit at the
commencement of said circuit, a switch controlled by an electric device, preferably
an electro-magnet, in shunt with the circuit upon which is the switch, the resistances
of the shunt circuit being greater than the resistance of the line circuit under
normal conditions; but, if a wire breaks in the main circuit, the resistance becomes
greater than the resistance of the shunt circuit, and the magnet is energized so that
it acts upon the switch to open the line or circuit at its commencement, so that the
broken wire is no longer a live wire.
My invention is adaptable to all character of circuits either light or power, and
is especially applicable for use in electric roads, as will hereinafter be fully
pointed out.
Fig. 1 is a diagramatic view showing my invention applied to a single circuit.
Fig. 2 is a vertical longitudinal section, switch and controlling device.
Fig. 3 is a plan of single switch and switch controlling device, gearing omitted.
Fig. 4 is a plan of double switch and switch controlling device, gearing being
shown.
Fig. 5 is a side elevation showing position of and support for switch box.
Fig. 6 is a diagramatic view showing my invention applied to an electric railway
with sub sections in main section.
Fig. 7 is a diagramatic view showing my invention applied to a multiple circuit.
Fig. 8 is a diagramatic view showing my invention applied to a number of main
electric railway sections.
Fig. 9 is a diagramatic view of double switch and connections.
Fig. 10 is a diagramatic view of single switch as used in Fig. 8.
Fig. 11 is a diagramatic view of single switch as used in Fig. 6.
Fig. 12 is a diagramatic view showing signalling devices and electrical connections
used with switch devices.
Figure 1 represents a circuit B in which D is the dynamo, and D' a lamp in the
circuit. At a point close to the commencement of the circuit I insert the device X,
shown in Figures 2 and 3, Figure 2 being a section, and Figure 3 a plan. In this
device A is a switch lever pivoted at a, and at the pivoted end, by means of the
binding post a', connection is made with the wire of the main circuit. The other
end of lever A rests against a spring contact b, connected to the binding post,
connected with which the wire of the main circuit beyond the switch is connected.
Therefore, when the lever A is in contact with spring contact b, the circuit is
complete through the switch. The switch lever stands vertically and is normally
held against the contact, by means of the catch on the pivoted arm C, engaging
a projection from the lever. The pivoted arm C carries the armature of
a magnet E, the catch holding the lever when the armature is unacted on by the
magnet. The magnet E is in shunt with the main circuit. The resistance of the
magnet E is greater than the resistance in the main circuit B, aud consequently
normally, the magnet is not energized, and the catch of armature holds the lever in

page_text: position against the contact band the circuit is active on the line. If by any
reason the wire of circuit B should break, the resistance in the line will at once
become greater than the resistance of the shunt circuit, and the magnet E will
become energized and the armature drawn in releasing the catch from lever A,
and the lever will fall, opening the main circuit at its commencement, and the
broken wire will no longer be a live wire.
If the circuit be a multiple circuit, as shown in Figure 7, then the device X is
preferably placed at each circuit of the multiple. Thus I place one at I
contiguous to the dynamo. I place one at the branch 2, contiguous to the point of
departure from the main line." I place one on the main line just beyond this
branch 2, that being the commencement of a new circuit which extends to the
branch 3, and at the commencement of this branch 3, I place a similar device,
and so on throughout, each circuit of the multiple where it commences is provided
with a device, such as before described, so that, if in any of these circuits a wire is
broken, the current is cut off from passing through the circuit in which the wire
is broken, so that there is no danger of live wires. When a ground circuit is used,
I use a single switching device (see Fig. 10). Where there is a metallic circuit
I prefer to use a double switching device with two levers, one controlling the
connection of one wire, the other controlling the circuit to the other wire, both
levers being controlled by the armature C of magnet E, (as shown in Figs. 4,
7 and 9) where in multiple circuits, I use a device for each circuit, and it is
desired to register at the central station or power house, the circuit in which the
break has occurred, so that it may be repaired, I provide the following mechanism.
Connected in series in a circuit independent of the line circuits, are a series
of discs, F, F', F &c., said dises corresponding in location and position and
number with the devices X. These devices are insulated at that portion of the
periphery upon which are the insulating strips see Figs. 2, 4 and 12) F has one
strip, F two, F2 three, and so on. are brushes resting upon these dises connected
in series, and in the circuit at the power house is a signal L. On the shaft f² of
each of discs F, F &c., is a gear G, which meshes with gear wheel G and gear
wheel G. Upon the shaft of gear G2 is a gear which meshes with the spring
acting gear G, and fixed upon the shaft of gear G' is a disc having a notch g in
its periphery, in which is adapted to rest the toe piece of the arm H connected to
arniature C.
When the magnet E is energized as before described, the movement of the
armature prevents the further reception of current in the main circuit, and it also
moves the toe piece from the notch g, allowing the spring gear G to act, and
signal is given. The number of signal is dependent upon the number of strips
Thus, if the wire broken is in the circuit corresponding to disc Fone signal will be
given, if F, two signals, and so on, so that the person at the station can tell by the
number of the signal, the location of the break. Any other mechanism controlled
by the circuit breaker to give the signal may be used. In practice it is preferable
to make the gear G' such that it will revolve once in two revolutions of disc F, so
that two sets of signals may be given before the toe piece again engages the
notch 3.
I can operate the levers of switch device by hand, if desirable to cut off the
current from any circuit, in the following manner.
Jis a bell crank to one end of which is attached a cord j, which passes to the
desired point. The other end is in aligument with armature C, so that when
the string is pulled the armature is forced toward the magnet and the levers
released. See Figs. 2 and 5, in which Fig. 5 is a view of pole with controlling
switch mechanism and cord extending downward to the point where it can be
reached.
As before stated, my invention is especially applicable to electric railways, and
in Figures 6 and 8 I have illustrated my improvement applied to such a use.
Taking first Figure 8, K is the dynamo; K' the trunk line; k, k³, k², k³, k*, the
feed wires leading from the line Kto the trolley wire of its corresponding trolley

page_text: section, 1, 1, ², 1³, 1. The end of each of the sections, 1-1 is connected with
the ground through resistance, which resistance is greater than that of the car
motors. In shunt with each circuit, 1, 1,-1, and at the point where the said
circuits connect with their corresponding feed wire k, k¹-k (that is at the
commencement of each circuit of the trolley wire) I place the device X hereinbefore
described in a shunt circuit (see Figs. 8 and 10) the resistance of whose shunt
circuit magnet is greater than the motor resistance or the trolley section circuit
resistance, so that, so long as the trolley wire of that circuit remains intact the
magnet is not energized, but when the wire of any section is broken, its corresponding
magnet is energized and the current cut off from that section of the trolley wire.
As, however, the sections I, l', &c. are of considerable length in practice, and
there being also several supporting poles in a section, a wire may break when two
or more cars are in the section, and a car between the section magnet and the
break, in which case the trolley wire of that section would still remain alive. This
can be obviated by the motormen of all the cars in a section cutting out their
motors when the break occurs, when the magnet corresponding to said section would
at once act and cut off current from the wire. However, a better method than this
is shown in Fig. 6, where I form in each section, - (one section and a part of
another being shown), a number of shunt circuits, such as shown in Figure 11,
each having a magnet controlling a switch upon the trolley subsection line, so that
if the break takes place anywhere in the sub-section, the distance between the
break and a magnet will be so short that the possibility of a car being there is
remote, and if there, the time which it remains there would be short.
In practice I propose placing the shunt magnets and switches at the points where
there are supporting poles. The theory of this last method shown in Figure 6, is
that each car makes a separate circuit, and, if I arrange my magnets and switches
to provide for the maximum number of possible circuits thus formed, I am in
position to cut the current from a broken wire at any point. The registering
devices heretofore described can be used with the method shown in Figures 6 and 8
just described, so as to indicate the location of the broken wire.
Having now particularly described and ascertained the nature of my said inven-
tien, and in what manner the same is to be performed, I declare that what I
claim is :-
1. The combination with an electric circuit, of a normally closed switch in said
circuit, an electric device in a closed shunt with said circuit and adapted to control
said switch, the resistance of said device being greater than the resistance of the
cirenit, the arrangement being such that when the resistance of the circuit is unduly
increased said device is energized and said switch is opened.
2. The combination with an electric circuit, of a normally closed switch at the
cominencement of said circuit, an electric device in a closed shunt with said circuit
and adapted to control said switch, the resistance of said device being greater than
the resistance of the circuit, the arrangement being such that when the resistance
of the circuit is unduly increased said device is energized and said switch is opened.
3. The combination with an electric circuit, of a plurality of normally closed
switches in said circuit, each switch being controlled by an electric device in a
closed shunt with said circuit, the resistance of which device being greater than the
resistance of the circuit, the arrangement being such that when any device is
energized its corresponding switch is operated to open the circuit at said switch.
4. In combination with multiple electric circuits, each being provided with a
normally closed switch, an electric device in a closed shunt with its corresponding
circuit and controlling its corresponding switch, the resistance of each of said
devices being greater than the resistance of its corresponding circuit, the arrange-
ment being such that when any of said devices is energized its corresponding switch
is operated and its circuit broken.
5. In combination with multiple electric circuits each being provided at its
commencement with a normally closed switch, an electric device in a closed shunt

page_text: with its corresponding circuit, and controlling its corresponding switch, the
resistance of each of said devices being greater than the resistance of its corre
sponding circuit, the arrangement being such that when any of said devices is
energized its corresponding switch is operated, and its circuit broken.
6. In combination with multiple electric circuits, a plurality of normally closed
switches in each of said circuits, each switch being controlled by an electric device
in a closed shunt with its corresponding circuit, the resistance of each of said
devices being greater than the resistance of its corresponding circuit, the arrange-
ment being such that when any device is energized its corresponding switch is
operated to open its corresponding circuit at said switch.
7. In combination with an electric circuit, a normally closed switch in said
circuit, an electric device in a closed shunt with said circuit and adapted to control
said switch, the resistance of said device being greater than the resistance of the
circuit, the arrangement being such that when the resistance of the circuit is
undly increased said device is energized and said switch is opened, a circuit
independent of the first mentioned circuit, a signalling device in said circuit,
adapted to be thrown into action when the electric device is energized and a
receiving device in said circuit.
8. The combination with an electric circuit, of a plurality of normally closed
switches in said circuit, each switch being controlled by an electric device in a
closed shunt with said circuit, the resistance of which device heing greater than the
resistance of the circuit, the arrangement being such that when any device is
energized its corresponding switch is operated to open the circuit at said switch,
a circuit independent of the first mentioned circuit, signalling devices equal in
number to said switches, and the corresponding signalling device being adapted to
be thrown into action when its corresponding switch is opened, and a receiving
device in said circuit.
9. In combination with multiple electric circuits, each being provided with a
normally closed switch, an electric device in a closed shunt with its corresponding
circuit and controlling its corresponding switch, the resistance of each of said
devices being greater than the resistance of its corresponding circuit, the arrange-
ment being such that when any of said devices is energized its corresponding
switch is operated and its circuit broken, a circuit independent of the first
mentioned circuits, signalling devices equal in number to said switches, and the
corresponding signalling device being adapted to be thrown into action when its
corresponding switch is opened, and a receiving device in said circuit.
10. In combination with multiple electric circuits, a plurality of normally
closed switches in each of said circuits, each switch being controlled by an
electric device in a closed shunt with its corresponding circuit, the resistance of
cach of said devices being greater than the resistance of its corresponding
circuit, the arrangement being such that when any device is energized its corre-
sponding switch is operated to open its corresponding circuit at said switch, a
circuit independent of the first mentioned circuits, signalling devices equal in
number to said switches and the corresponding signalling device being adapted
to be thrown into action when its corresponding switch is opened, and a receiving
device in said circuit.
11. The combination with an electric circuit of a normally closed switch in said
circuit, an electric device in a closed shunt with said circuit and adapted to
control said switch, the resistance of said shunt circuit being greater than the
resistance of the circuit, the arrangement being such that when the resistance of
the circuit is unduly increased said device is energized and said switch is opened.
12. The combination with an electric circuit of a plurality of normally closed
switches in said circuit, each switch being controlled by an electric device in a
closed shunt with said circuit, the resistance of which shunt circuits being greater
than the resistance of the circuit, the arrangement being such that when any
device is energized its corresponding switch is operated to open the circuit at said
switch.

page_text: 13. In combination with an electric circuit, a normally closed switch in said
circuit, an electric device in a closed shunt with said circuit and adapted to control
said switch, the resistance of said shunt circuit being greater than the resistance of
the circuit, the arrangement being such that when the resistance to the circuit is
unduly increased said device is energized and said switch is opened, a circuit
independent of the first mentioned circuit, a translating device in said circuit,
adapted to be thrown into action when the electric device is energized, and a
receiving device in said circuit.
14. The combination with an electric circuit, of a plurality of normally closed
switches in said circuit, each switch being controlled by an electric device in a
closed shunt with said circuit, the resistance of which shunt circuits being greater
than the resistance of the circuit, the arrangement being such that when any
device is energized its corresponding switch is operated to open the circuit at said
switch, a circuit independent of the first mentioned circuit, translating devices
equal in number to said switches, and the corresponding translating device being
adapted to be thrown into action when its corresponding switch is opened, and a
receiving device in said circuit.
E
C
1005
LEWIS G. ROWAND.
Haseltine, Lake & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.