Improved Means for Electrically Operating Electrical Railway Switches.
Year: 1898

page_text: Date of Application, 30th Aug., 1898-Accepted, 12th Nov., 1898
COMPLETE SPECIFICATION.
Improved Means for Electrically Operating Electrical Railway
Switches.
We, ROLLIN ALGER BALDWIN and HEAVLON ROWLAND, both of South Norwalk,
in the County of Fairfield and State of Connecticut, United States, Electrical
Engineers, 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:
This invention has reference to an electrically operated railway switch, its
object being to provide an automatic device for actuating the switches in the
tracks of electric railways.
In carrying out this invention, an electro-magnet is located in a box in the road-
way at some convenient point adjacent to the switch tongue, and current to
actuate the magnet is taken from the return circuit of the railway, which,
ordinarily, is the rail. In order to do this, a short section of the rails ahead of
the switch is insulated and when the switch is to be turned, the return circuit
from the moving vehicles is passed into the insulated section of the rails, thence
to the magnet and finally to the return circuit again. If the switch is not to
be turned, the car passes over the insulated section of rails by its momentum,
the current being cut off to prevent the energising of the magnet.
This type of apparatus is already known in several forms and modifications
and our present improvements relate to the details of construction of the devices
whereby the armature of the magnet transmits its motion to the switch point or
tongue.
These improvements will be described in detail with reference to the accom-
panying drawings in which Figure 1 represents a side elevation of the mechanism
removed from its box and with parts broken away, and Figure 2, an end view
of the same. Figure 3 is a diagram of the electric circuits.
The electro-magnet «, of the horse-shoe type, is secured in a frame b, by means
of bolts passing through its back yoke. It is mounted in an upright position
with the two poles pointing downwards in a horizontal plane. A soft iron bar c,
constitutes the armature of the magnet and normally rests upon the cross piece
of the frame. Its extremities are perforated or notched to fit respectively over
two brass rods 63 which act as guides for the armature. A hole is formed through
the centre of the armature, through which passes the end of an upright brass
thrust rod d. Cross pieces or projections d are fixed in the thrust rod above
and below the armature, to cause the rod to partake in the motions of the armature
while at the same time permitting the rod to swing laterally in the plane of the
armature. The thrust rod passes vertically upward between the two magnet
bobbins and through an opening in the back yoke above which it is provided
with a wedge shaped head d. A reciprocating bar e, placed loosely in guides
formed on the frame b, extends out at one side as shewn, and connects with the
switch point f, in the railway track. The bar is provided with an opening e¹

page_text: in which the wedge-shaped head of the thrust rod stands, and the lateral parts
of this opening are inclined to correspond respectively with the inclined sides
of the head d. On the top of the frame b is fixed a plate g having a wedge-shaped
projection or part gl pointing towards the wedge-shaped head d² of the thrust
rod. The sides of this wedge-shaped part g¹ stand at the same angle to each other
as do those of the head d². This part gi is formed between two cavities 2 in
the plate g, into either of which cavities the head d is adapted to be thrust as
will be hereinafter explained. Two springs ii, connect respectively to the opposite
sides of the thrust rod d and to the bar e by means of cords passing over pullies 3.
The circuits are shewn in diagram Figure 3, wherein it will be seen that a con-
ductor 1, extends from the insulated section of rails 2, to the magnet, whence a
conductor 3 connects again with the main line of rails.
The operation is as follows:-The normal position of the thrust rod is against
one or the other of the sides of the opening e' in the reciprocating bar and with
its point immediately below and slightly to one side of the point of the part g
one of its normal positions being shewn by Figure 1. If, upon the approach of
a car, it is desired to throw the switch, the motor-man leaves the current on,
whilst he travels over the insulated section of rails. The return current from
the motor then leads through and energises the magnet, causing it to lift its
armature c, the motion of which is communicated to the thrust rod d. As the
thrust rod rises, one side of its wedge-shaped head comes into contact with one
side of the part 1 and it is forced in a lateral direction, the other side of the
wedge-shaped head meanwhile resting against the side of the opening el in the
reciprocating bar, forcing the said bar over, and throws the switch point. This
motion of the reciprocating bar relaxes one of the springs on that side towards
which the motion is made and puts the other spring under tension. As soon as
the car passes off from the insulated section of rail, the magnet is de-energised
and the armature in falling carries the wedge-shaped head of the thrust rod
downward, whilst the spring, which was previously put under tension, swings
it laterally until finally it comes to rest against the opposite side of the opening e¹
in the reciprocating bar. The next time current is passed through the magnet,
the wedge-shaped head of the thrust rod passes up on the opposite side of the part g¹
and moves the reciprocating bar in the opposite direction. If the switch is not
to be thrown, upon the approach of a car, the motor-man cuts off the current
and permits the car to roll over the insulated section of rails by its momentum.
It will be understood that the part g¹ may be a projection from the plate g
instead of being formed within it as shewn. It will also be understood that the
thrust rod d may have two cams upon it, the second one being directly behind
or below the head d and the first one acting upon the part g' whilst the second
acts upon the reciprocating rod e.
The function of the fixed part g' is merely that of a guide and purchase for the
rod d, and in order to ensure the least friction between the sliding surfaces, any
of the usual appliances such as anti-friction rollers may be inserted therein.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same may be performed, we declare that what
we claim is:
1. In an electrically operated railway switch, the combination of an electro-
magnet and its armature, a rod moved by the said armature, a wedge-shaped
cam against the faces of which the said rod is driven by the magnet to deflect
the rod in one direction or the other, means for determining which of the said
cam faces the rod shall be driven against, and a switch tongue connected with
the rod and partaking of its deflected motions, substantially as herein before
described with reference to the accompanying drawings.
2. In an electrically operated railway switch, the combination of an electro-
magnet and its armature, a rod attached to and moving with the armature, a
guide adapted to deflect the rod when it is moved by the armature, and a switch

page_text: moving bar under the control of the guided movement of the rod, substantially
as hereinbefore described with reference to the accompanying drawings.
3. In an electrically operated railway switch, the combination of an electro-
magnet and its armature, a thrust rod carried by the armature, a reciprocating
bar connected with the switch point, the thrust rod and bar being provided with
corresponding cam surfaces, and a fixed guide directing the movement of the
thrust rod and so controlling the movement of the reciprocating bar, substantially
as hereinbefore described with reference to the accompanying drawings.
4. In an electrically operated railway switch, the combination of an electro-
magnet and its armature, a thrust rod carried by the armature and having a
wedge-shaped cam at its extremity, a reciprocating bar connected with the
switch point, the thrust rod and bar being provided with corresponding cam
surfaces and a wedge-shaped fixed cam against which the cam on the thrust rod
is adapted to strike to deflect the latter and cause it to act on the reciprocating bar,
substantially as herein before set forth with reference to the accompanying
drawings.
5. In an electrically operated railway switch, the combination of an electro-
magnet and its armature, a rod pivoted to the armature and carrying a wedge-
shaped cam, two opposing springs connected respectively to the opposite sides of
the thrust rod, a fixed wedge-shaped cam pointing towards the cam on the rod,
and a reciprocating bar connected with the switch point and adapted to be engaged
by the rod, substantially as hereinbefore described with reference to the accom-
panying drawings.
Dated this Twenty-ninth day of August A D 1808
.