Improvements in Electric Block Signals for Railroads.
Year: 1895

page_text: Date of Application, 7th Aug., 1895-Accepted, 7th Sept., 1895
COMPLETE SPECIFICATION.
Improvements in Electric Block Signals for Railroads.
I, ANGUS CAMERON GORDON, of the City of Rochester, in the County of
Monroe and State of New York, United States of America, Manufacturer, 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 improvement relates to electric block-signals for railroads, in which, where
a train or car is on the block, a short circuit is established through the wheels and
axle, thereby opening the main circuit that controls the signal and leaving a
standing signal of "danger." On the removal of the train or car from the block
the relay operates by closing the main circuit and changing the signal to "safety."
Such devices are already known, and I lay no claim to such broadly.
My invention consists in certain combinations of parts hereinafter claimed,
hereby the parts in the signal-box are made simpler and more effective in
operation.
11
In the drawings,
Figure 1 is a diagram exhibiting one block in a railroad and the circuit connected
therewith for operating the signal.
Fig. 2 is a longitudinal vertical section of the signal-box.
Fig. 3 is a similar section at right angles to Fig. 2.
Fig. 4 is a face view of the shifting signal.
Fig. 5 is a sectional plan view of the same.
Fig. 6 is an enlarged face view of the conducting plates.
A indicates one block in a railroad, the same being insulated from the adjacent
blocks by non-conducting packings a a.
B is the signal-box. Within this box are located the shifting signal C and the
connections by which it is operated. Preferably the signal consists of a disk
attached to a shaft b, by which it receives half-rotation in opposite directions, but,
if desired, may be made of other form and arranged to slide instead of rotate.
One half of the face of the signal is red and the other half white to indicate
danger " and "safety," and over one-half is placed a black screen c, Fig. 5,
behind which the unused half of the signal is hidden when the other half is in use.
The signal is turned in one direction by a rack d, which engages with a pinion f
on the shaft and it is retracted or turned in another direction by a weighted
cord or chain g, that winds on a pulley h of the shaft.
66
With the block A is connected an electric circuit, consisting of a battery D with
two wires 1, 2, connecting with the opposite rails at one end of the block, and
wires 3, 4, connecting with the rails at the opposite end of the block, said wires 3, 4,
connecting at their outer ends with an electromagnet E, which operates a switch 1,
and by bringing it in contact with an electrode k closes the main circuit and
operates the signal, as will be bereinafter described.
It will be seen that when the block is clear the circuit through the wires 1, 2, 3, 4,
is closed and the armature switch i is drawn in contact with the electrode k, and the
main circuit though the signal-box is closed; but in case a car is on the block, as
shown at j, a short circuit is established through the wires 1, 2, the rails, and the
wheels and axles, as indicated by the arrows, Fig. 1, and the magnet E is
consequently demagnetized, and in that case the switch i in the main circuit is open,
as shown. This feature, as before stated is old.

page_text: The mechanism and connections in the signal-box for operating the signal are as
follows:-
F is a vertically-sliding rod forming a connection provided at its lower end with
an armature which engages with an electromagnet G when drawn down. This rod
is pivoted at m to a rock-lever n fulcrumed at o to the side of the box. The upper
end of the rod F is connected with the sliding rack d by a rod H. When the sliding
rod is drawn down, the rack gives rotary motion to the signal-shaft, as before
described. I is a motor provided with a pulley p, on which winds a cord
attached
to the outer end of lever n. When the motor is operated the pulley draws the
sliding-rod F down-ward and brings its armature near to the magnet G. Instead of
the cord winding on the pulley a rack and pinion may be used.
The sliding-rod F has a projecting pin r, forming a switch, which plays between
two conducting-plates s, s', separated from cach other and attached to an insulated
block t. The pin rests in contact with both plates. To the bottom of plate s¹ is
attached a small metallic contact plates, separated from the plates by a thin
insulated block u. In its down stroke the pin r passes from contact with the two
plates 8, 8, to contact with plates and the small contact-plates s³, thereby changing
the circuit, as will presently be described. The circuit for operating these parts
has a battery K, from which extends a wire 5, connecting with the switch-
armature i, and a wire 6 extending to the conducting plates. 7 is a wire:
connecting the plates with the motor I. 8 is a wire connecting the contact-
plate with the magnet G. 9 is a wire connecting magnet G with the motor I,
and 10 is a wire connecting said motor with the electrode k.
When the block A is clear the circuit through the relay is closed and the switch-
armature is also closed, which closes the main circuit through the signal-box.
The current from battery K passes through wire 10, giving motion to the motor,
thence through wire 7, the conducting-plate ', the pin r, (which is then at its
highest point,) through the plate s, and through wire 6 back to the battery. The
motion given to the motor winds up the cord 9, draws down with it the rod F and
its pin, until finally the pin passes from contact with the two plates, s', and
comes in contact with the plates 8, s². The circuit is now changed, passing from
battery K through wire 5, armature i, wire 10, wire 9, the magnet G, (charging
same), the wine 8, conducting-plate s², the pin i, conducting-plates, and wire 6 back
to battery. This stops the motor, and by changing the magnet G draws down and
holds the armature, which has previously been drawn down near to the magnet by
the motor. In this position the signal has been shifted so that the white stands
outward as the signal of "safety." It is so retained as long as the block is clear.
When a car passes onto the block the relay is short-circuited and the switch of the
main circuit opened, as before described, and the armature released from the
magnet G, and the signal is then shifted from white to red, indicating "danger,"
by means of the weighted cord g, and so remains so long as the car remains on the
block. A broken rail, or any other defect in the track by which the circuit is
broken, sets the signal to "danger" in the same way.
The essential feature in this invention is the motor or its equivalent, for drawing
down the connection that operates the signal, and the electromagnet for holding
the same in its depressed position so long as the block is occupied. The magnet
alone cannot produce the desired effect, as the throw is too great to enable it to act
upon the arinature. The motor draws it down within the reach of the magnet, and
the latter seizes it and holds it, while the motor releases its hold. The whole is
accomplished with the minimum expenditure of battery power.
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. In an electric railroad signal, the combination of a shifting signal, a magnet,
a rod between the signal and magnet provided with an armature, a motor, a cou-
nection between the motor and rod whereby the latter is operated, and an electric

page_text: circuit connected with the motor and magnet and provided with a switch, whereby
when the circuit is closed the motor first draws down the armature, then stops,
while the magnet continues to hold the armature in place as described.
2. In an electric railroad signal, the combination of a shifting signal, a magnet,
a rod between the signal and magnet provided with an armature, a motor, a con-
nection between the motor and rod whereby the latter is operated, an electric
circuit connected with the motor and magnet provided with a switch, whereby
when the circuit is closed the armature is drawn down by the motor and held by
the magnet, and means for retracting the sigual when the armature is released by
the magnet, as specified.
3. In an electric railroad signal, the combination of a shifting signal, a magnet,
a connection provided with an armature operating with the magnet, a motor, a
circuit connected with the motor and magnet whereby the motor first draws the
armature down to the magnet and then stops while the magnet continues to hold
the armature in place, and a circuit connected with the block controlling the main
circuit, the whole arranged to operate in the manner and for the purpose specified.
4. The combination of a shifting signal, a rod for operating same provided with
an armature at its end, an electro-magnet for holding the armature when drawn in
connection therewith, a motor connected with the rod to draw the same in connection
with the magnet, electrical connections for giving motion to the motor and charging
the magnet, and means for retracting the signal when released by the magnet as
specified.
5. The combination of a shifting signal, a rod for operating the same provided
with an armature at its end, a magnet for holding the armature when in contact
therewith, a rock lever to which the rod is pivoted, a motor with a connection for
operating the rock lever, electrical connections for giving motion to the motor
and charging the magnet, and means for retracting the signal when released by the
magnet, as herein shown and described.
Dated this 7th day of August. 1895
ALLISON BROS.,
Agents for the Applicant.