Improvements in Electric Railways.
Year: 1893

page_text: COMPLETE SPECIFICATION.
Improvements in Electric Railways.
I, SYDNEY PITT, of Sutton, in the County of Surrey, Gentleman, (a com-
munication to me from abroad by "The Universal Electric Company of the City
of New York," a corporation organized under the laws of the State of West
Virginia, U.S.A., and having an office at 36 New Street, in the City of New
York, State of New York, U.S.A.,) 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 :-
The invention relates to that class of electric railroads having underground
conduits in which the contact devices are contained and operated.
The object of the invention is to provide a system that may be economically
installed and operated and in which loss of current due to leakage, as well as the
element of danger where high tension currents are employed, may be practically
eliminated.
At
To this end is employed a conduit of any ordinary construction that may as
usual be located between the rails of the track. Within this conduit or suitably
contiguous thereto the insulated lead or leads of the circuit may be located.
intervals within the conduit are supported closed contact boxes with each of which
the circuit is connected, the connection being lead into the interior of the box to
a contact plate or device therein, all exterior connections being completely insulated.
The boxes are provided with a projecting insulated switch arm or contact closing
device normally lying in the path of a brush or contact plate carried by the car,
by means of which the insulated contacts within the box are brought together and
There are therefore no
the circuit completed through the motor on the car.
uninsulated or exposed conductors within the conduit, and the motor on the car is
only connected with the circuit while the brush carried thereby is bearing against
the switch arm of the contact boxes. There is, therefore, no possibility of leakage
except during this brief period. And to prevent leakage during such time each
box may be charged with oil and provided with a porous portion or wall through
which the contained oil gradually percolates keeping the exterior of the box and
the parts connected therewith coated with a layer or film of oil that prevents the
deposit or condensation of moisture thereon. The box may be completely charged
with oil and the contacts therein through which the connection of the motor on
In order to obviate
the car with the main circuit is completed immersed in oil.
the necessity for examination and periodic filling of the boxes, each box may be
connected with a pipe system containing oil under pressure. This not only insures
that the boxes shall be completely filled at all times, but the pressure causes the
oil to penetrate the porous medium of the boxes and maintain their exterior
parts and connections constantly covered with oil. The brush or contact device
carried by the car always ensures the opening of the circuit at the brush before
the circuit can be opened at the contacts within the boxes. Formation of sparks
within the boxes and the consequent destruction of the contacts and carbonization
of the oil is prevented, so that when the system is once installed, the boxes and
circuit connections therein will require no attention for an indefinite period, while
the switch arm of the box and the brush carried by the car may be renewed or
repaired as occasion may require.
The invention as well as the details of construction are more fully hereinafter
set forth, and also shown in the accompanying drawings in which―
Figure 1 is a rear elevation of the car and a view of the track, road bed, and
conduit in cross-section.
ירד
ical central section through one of the boxes.

page_text: Figures & bottom view thereof with the bottom plate removed.
Figure 4 a diagram of the system.
Figure 5 a transverse longitudinal section through the brush.
Figure 6 a face view thereof.
Figures 7, 8 and 9 are view showing one manner of constructing the switch arm
projecting from the box.
Of course in this system both leads or sides of the main circuit may be insulated
and connected with opposite series of boxes in the conduit as above suggested, or
there may be one insulated lead, one series of boxes and the track may constitute
the other side of the circuit.
In Figure 1, A indicates the hanger on the car carrying the brush or contact
plate B and C C indicate a pair of contact boxes arranged on oppposite sides of
the conduit and supported upon the wall thereof in any suitable manner, D being
the switch or contact arms of the boxes against which the brush B works. In
Figure 4, G is the generator and G G¹ the insulated leads or sides of the circuit
thereof. Each box C is connected with the circuit by an insulated connection g g.
P indicates a pump and P¹ P the opposite sides of a pipe system into which oil
or other fluid insulating material is forced under pressure by the pump. The
interior of each box C is connected with each side of the pipe system by a branch
pipe p, which may be provided with a cock p'. Bis the brush carried by the car D
the switch arms of the boxes and M the motor on the car.
The boxes are shown in detail in Figures 2 and 3. They may consist of a
casting C¹ open at both ends and having about midway of its length an internally
projecting flange c and two hubs or tubular projections, one p² for the connection of
the oil pipe p, and another g¹ for the connection of the insulated branch conductor g.
One half of the box, that is, the upper half as seen in Figure 2 may be annular
while the lower half below the flance c may be semi-circular on one side and have a
right angular extension C² from the other. This end of the box may be closed by
a cap or lid C³ tightly secured by means of bolts passing through lugs or ears
thereon or otherwise. The projecting hub g' is shown as formed upon the square
projection at the box and instead of extending out at right angles from the wall
thereof it is preferably curved downwardly as indicated. The interior bore thereof
is preferably larger than the opening g² in the end thereof and the opening g³
leading into the box, so that when the insulated conductor g is inserted asphaltum
or other heated insulating material g* may be poured in. Of course any suitable
way of leading in the conductor and sealing the entrance may be adopted. The
end of the conductor within the box carries or is connected to a contact plate H
mounted upon an insulating support having two projecting ends h between which
works a contact arm I carried on the end of a rod or shaft l'extending up through
the box. This rod may be supported and provided with a bearing as follows:
Beneath the flange c is placed a plate K of wood or other insulating material.
Above the flange is a similar plate K', on which is placed a relatively thick washer
or mass of porous insulating material K2, such for instance, as asbestos, earthenware
or other suitable material, fibrous or otherwise. Above the washer is another
plate K³ of insulating material. A flanged sleeve L is passed through the
plates K, K, K2, K³, the flange abutting against the lower plate K, and is
provided at the top with a screw clamp nut L'. The rod I' has its bearing within
the sleeve L and upon its inner end carries the contact arm I which is provided
with a tubular hub fitting upon and secured to the end of the shaft and having
flange between which and the flange of the sleeve L, a packing washer i is placed.
This is for the purpose of preventing an excessive leak of oil along the shaft or
rod I. The laterally projecting switch or contact arm D may be composed, as
shown, of two plates of metal lying against each other and secured to the outer
end of the shaft I¹. These plates are preferably of spring metal, such for instance
as tempered brass, copper or other metal, or compositions of metals. Its short end
is connected with one end of a spiral spring enveloping the shaft and having its
other end connected with the clamp nut L. When therefore the switch arm D is
a

page_text: operated as presently described, there are two yielding or resilient connections, one
the arm D itself, the other the spiral spring, and a third may if desired be provided
by also making the interior contact arm I elastic. This prevents the jarring of the
box, its supports and electrical connections when the brush on the car comes in
contact with and leaves the switch arm D. Oil from the connection p² is introduced
into the large end of the box and finding its way through and past the insulating
plates K, K, percolates through the porous medium K2 and past the plate K³ to
the top of the box. By preference there shall be an accumulation of the oil here,
and for this purpose the upper edge or wall of the box is caused to project above
the level of the clamping nut L', and also preferably above the end of the sleeve L,
so that there is a perfect protection against moisture entering along the bearing of
the shaft I, and a thorough lubrication of its bearing is ensured. The sweeping of
the oil up through the box is preferably so controlled that there is but a slight
discharge over the edge of the box that will be only sufficient to keep the walls
and bottom of the box and the insulation of the conductor g coated with a suitable
film of oil. A receptacle may, however, if desired be placed within the conduit
beneath each box to collect such dripping of the oil as may occur, and from which
the collected oil may from time to time be pumped or otherwise withdrawn. The
details of construction shown and described are suitable, practical and efficient, but
obviously they might be varied in many ways.
The strain of the spiral spring around the shaft 1' that occurs when the arm D is
struck and strained to one side by the brush on the car should preferably be in a
direction tending to screw up the nut. When thus arranged there is no liability of
the nut becoming loose. The nut may also be pinned to the washer K³. As
shown in Figure 4 the boxes on opposite sides of the conduit are arranged in
alternation and the brush B is of a sufficient length to be always in contact with at
least two of the switch arms D on opposite sides of the conduit. As shown in the
diagram opposite series of boxes may be employed and both leads of the circuit
insulated, but the principles of the invention may as before stated be employed in a
system where the rails form one side of the circuit. In such an organization the
brush B should be long enough to be always in contact with two switch arms D.
The general character of the brush that is preferred is indicated in Figures 4, 5
and 6. It is composed of a body of insulating material b, upon which the contact
plate connected with the motor on the car is mounted. The ends of the plate /
do not extend to the end of the body b, but there is at each end of the brush a face
of insulating material as seen in Figure 4, extending beyond the end of the contact
plate . These insulated faces at each end are preferably below or inside of the
plane of the face of the contact. As the car traverses the track the brush
successively strikes the laterally projecting switch arms D which bend and are
moved to one side as indicated in Figure 4. The shaft I partially turns in its
bearing and the contact arm carried thereby, is pressed against one of the contact
plates h of the main line contact. The brush contact establishes a good rubbing
connection with the switch arms D and the circuit is completed through the motor
on the car. As the brush leaves a switch arm D the arm passes off of the contact
plate b with an abrupt snap on to the insulated face extending beyond the end of
the contact, the main circuit is therefore opened at this point, and the connection
within the box cannot be broken until the switch arm runs off of the insulation b.
Of course the operation is precisely the same where boxes are arranged on each
side of the conduit, the brushes B then having contact plates on each side and
insulated end portions on each side as already described. In the event of the
backing of the car the switch arms D, as seen for instance in Figure 4, that are
bearing against the brush contact plates will maintain their position, as is obvious,
and there will therefore be no opening of the circuit within the boxes, the switch
arms being still held in their position after they have run off on to the insulated
end portion b. Were it not for the fact that the insulated part of the brush
extends beyond the contact plates, there might be a breaking of the circuit within

page_text: the box after the brush has passed from the switch arm and the arm by reason of
its resiliency follows up the receding brush. If at this time the arm were in
electrical connection with the contact plate of the brush the circuit would first be
open at the contacts within the box, but with the organization described, the
circuit will have already been open when the switch arm leaves the contact plate
of the brush and bears upon the insulation end thereof. By providing a brush
therefore with an insulated extension beyond each end of the contact plate the
circuit must always be broken at the brush and there is no liability of the circuit
first being broken in the box. In order to prevent wear and maintain the surfaces
of the switch arm clean and well polished, the ends of the brush may have inserted
into the insulation, metal plates 62 which are however, entirely insulated from the
contact plates of the brush. The boxes might be inverted, the switch arms then
being at the bottom instead of the top.
In this organization the boxes are arranged at the side of the conduit and not
beneath the slot. The contact devices of each box are controlled by a partially
rotatable shaft having its bearing in the box. The box can therefore be practically
hermetically closed so far as the shaft opening is concerned since it may be very
effectively packed. The switch contact arm that operates the shaft is itself
operated by the vertical face of the shoe working against the vertical face of the
head or end of the switch arm. There is therefore little danger of such contact
faces becoming covered with mud, dirt, snow or ice and of course they are kept
burnished by the rubbing contact between them.
Figures 7, 8 and 9 show a switch arm or device capable of yielding radially with
reference to the shaft I. Such a mode of operation is desirable, among other reasons,
because it eliminates any danger of breakage from the ends of the arms catching
on the shoe when the car is backed. The end or head of the switch arm also has
a motion about the axis of the arm and this ensures good contacts.
The upper portion of the shaft I projecting beyond the box is squared and its
end is screw threaded. A washer S is placed over the end of the shaft and rests
upon the shoulder formed by the squared portion thereof. A plate spring T
having a suitable aperture at its end is then placed over the shaft and brought
against the washer S. A block U, having a squared bore is then placed upon the
squared portion of the shaft, and clamped in position by nuts u. The block U,
has a lateral projection U', that is tapped to receive a rod V, that screws into it,
and is secured by a pin v.
The outer end of the rod enters loosely part way into the bore of a casting or
end piece W, but does not extend normally to the end thereof where the bore is
preferably enlarged. The casting may be shaped substantially as indicated, and
between the casting and block a spring V', envelopes the rod. To exclude dirt a
shield Y, is placed over the casting and rod and is soldered to the casting W, so
that pressure upon the casting permits it to yield or move inwardly toward the
shaft. A contact head 1, conforming in interior shape to the casting W, is mounted
upon or envelopes it and is secured thereto by split pins 2. The outer edge of this
head is rounded or curved and is preferably a segment of a circle and preferably a
semi-circle. The plate spring T, is attached to the block U by a screw t, extends
parallel with the rod V, for a short distance and is then bent down and up again
as shown and is attached to the contact head 1, at t¹, as indicated. The torsion of
the spring serves to hold the contact head in a normal horizontal position while it
is free to be pressed in by the brush or shoe carried by the car and to be pressed
out by the spring V₁, as well as the spring T. It also is capable of a turning
motion on the rod V. At the same time, the contact head may readily be removed
when worn and a new one substituted, this being done by removing the screw t¹.
Such in detail is the construction shown in the drawing. The details may, no
doubt, be varied in some respects without departing from my invention.
So far as I am aware, I am the first to provide, in systems of this kind, a switch
arm that may be moved laterally to establish contact and is capable of yielding

page_text: endwise to prevent breakage, when the car is backed also the contact head forming
part of the switch arm, which is capable of rocking or turning; and I desire to
claim these features broadly since it is obvious that the details of construction by
which such results may be accomplished may be varied.
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 system, the combination of the insulated lead or leads
of the main circuit, a series of boxes having interior contact devices with which the
main circuit is connected, each box being charged with oil or other insulating fluid
in which the contacts are immersed and having a porous medium or portion through
which the oil exudes and coats the exterior of the box and its connections, and a
switch arm carried by the box and controlling the enclosed main circuit contacts
and adapted to be operated by a contact brush or device carried by the
passing car.
2. In an electric railroad system, the combination of the lead of the main circuit,
a conduit, a series of closed boxes arranged therein, contact devices within each
box with which said lead is connected, a shaft having its bearings in the box and
carrying a contact arm within the box that works against said contact devices when the
shaft is partially rotated, the switch arm carried by the outer end of said shaft
adapted to be operated by the brush of the passing car to complete the main circuit
through the motor thereon, a pipe system for distributing oil or other insulating
fluid under pressure and connections between said system and the interior of the
boxes.
3. In an electric railway, the combination with the track and slotted conduit, of
a series of closed boxes arranged therein to one side of the slot and containing an
insulated contact device with which the lead of the circuit is connected, an upright
shaft having its bearing in each box, the shaft being partially rotatable to complete
the circuit from said contact device through the shaft, a switch contact arm pro-
jecting laterally from each shaft toward the centre of the conduit and having a
vertical contact face, and a contact shoe having an elongated smooth vertical
contact face carried by a car, the organization being such that the switch contact
arms are struck by the elongated vertical face of the contact shoe and the shafts
partially rotated, thereby successively completing the circuit through the motor on
the car, substantially as set forth.
4. In an electric railroad system, the combination of the lead or leads of the
main circuit, a conduit, a series of boxes arranged therein, contact devices within
the boxes with which said lead or leads is connected, the switch or contact arms of
the boxes adapted to be operated by the brush of the passing car to complete the
main circuit through the motor thereon, a pipe system for distributing oil or other
insulating fluid under pressure and connections between said system and the interior
of the boxes, each box having a porous medium or portion through which the oil
filtrates and coats the exterior of the boxes and their connections.
5. In an electric railroad system, the combination with the conduit of a series of
boxes located therein and containing oil or other insulating fluid therein under
pressure, the insulated lead or leads of the main circuit connected with contact
devices within the boxes submerged in the oil, and contact controlling devices
adapted to be actuated by the brush or contact device on the passing car to com-
plete the circuit through the motor thereon, each box having a porous medium or
portion through which the oil filtrates and coats the exterior of the box and its
connections.
6. In an electric railroad system, the combination of the lead or leads of the
main circuit, the conduit, a series of closed boxes arranged therein having interior
contact devices connected with the lead or leads, laterally projecting yielding switch
arms, and the brush carried by the car, the brush having a contact face or faces

page_text: against which the switch arms work and insulation extending beyond the ends of
the contact faces for the purpose set forth.
7. In an electric railroad system, the combination of the lead or leads of the main
circuit, the conduit, a series of closed boxes arranged therein having interior
contact devices connected with the lead or leads, laterally projecting yielding
switch arms, and the brush carried by the car, the brush having a contact face or
faces against which the switch arms work and insulation extending beyond the
ends of the contact faces, and the boxes being filled with oil, for the purpose set
forth.
8. In an electric railroad system, the combination of the lead or leads of the
main circuit, the conduit, a series of closed boxes arranged therein having interior
contact devices connected with the lead or leads, laterally projecting yielding arms,
and the brush carried by the car, the brush having a contact face or faces against
which the switch armis work and insulation extending beyond the ends of the con-
tact faces, and the boxes filled with oil, and having a porous medium or portion
through which the oil filtrates and coats the exterior of the boxes and their
connections, for the purpose set forth.
9. The combination substantially as set forth, of a conduit, the boxes therein
having the yielding switch arms D and the brush to be carried by the car having
a contact plate which works against and makes contact with the switch arms and
insulation extending beyond the ends of the contact plate.
10. The combination, substantially as set forth, of a conduit, the boxes therein
having the yielding switch arms D and the brush to be carried by the car having
a contact plate 6' which works against and makes contact with the switch arms and
insulation extending beyond the ends of the contact plate, the insulation extension
being below or inside of the plane of the surface of the contact.
11. The combination of the shell of the box, having two projections or coupling
connections, one p² for the connection of an oil supply pipe and one g¹ for the leading
in of a circuit conductor, the contact plate connected with the end of the conductor
within the box, the contact arm working against said plate, the shaft or rod to
which it is attached, its bearing, the porous packing surrounding the bearing and
closing the ends of the box, and the switch arm D carried by the shaft.
12. The combination substantially as set forth, of the box shell, the inwardly
projecting flange c, the plates of insulating material and porous packing, the flanged
sleeve, the shaft therein, the interior contact arm carried by the shaft, the switch
arm carried by its outer end, and the clamp nut on the screw and the spring
connected with the switch arın and the clamp nut.
13. The combination of the shell of the box, means for maintaining a supply of
oil therein, the vertical shaft or rod, its bearing within the box and the switch arm
carried by the upper end of the shaft, the edge of the box being extended up
beyond the bearing of the shaft to form a receptacle, and oil filling said receptacle
all substantially as and for the purpose set forth.
14. The combination of the box, the yielding or spring switch arm D, its rod or
shaft having its bearings in the box, the spring that holds the shaft in the normal
position, the contact arm carried by the shaft within the box, and the contact
plate within the box to which the insulated circuit wire is connected.
15. In an electric railroad, the combination of the contact devices arranged_at
intervals along the line of the road, a switch arm controlling each of them, and a
brush carried by a car, and adapted to operate the switch arm, to close the circuit
at the contact devices and between the brush and switch arm, the brush consisting
of insulating material and a contact plate beyond both ends of which the insula-
tion extends, whereby as the car passes, the circuit is first broken at the switch
arm and brush and then at the said contact devices, substantially as set forth.
16. The combination, substantially as set forth, of the closed box and its con-
tained contact devices and shaft, and the projecting switch arm for operating the
shaft, said arm being capable of yielding radially with reference to the shaft.

page_text: 17. The combination, substantially as set forth, of the box and its contained con-
tact devices and operating shaft, the switch arm projecting laterally from the
shaft and having a contact head capable of yielding radially with reference to the
shaft and rocking axially.
Dated this 17th day of October 1893.