IMPROVE- MENTS IN ELECTRICAL RAILWAYS AND TRAMWAYS
Year: 1884

page_text: I JOHN HOPKINSON F.R.S. of 4 Westminster Chambers Westminster in the
County of Middlesex do hereby declare the nature of said Invention for "IMPROVE-
MENTS IN ELECTRICAL RAILWAYS AND TRAMWAYS" to be as follows :—
My Improvements relate to the maintenance of electrical connection between a
fixed generator and a motor upon the car or other moving body-Upon the car,
electromotor, or vehicle, I carry a transverse bar or bars or instead or in addition &
roller or rollers which shall rub upon a roll against the conductor which is suspended
along the line-This conductor consists of a wire or wires for example like telegraph.
wire carried upon suitable insulators, the transverse bar or bars roller or rollers or
other conductors on the vehicle touching the underside of the wire or wires which
rests or rest on the said conductors on the vehicle, as the vehicle passes along.
I arrange the insulators so that the conductors or contact pieces on the vehicle
shall pass near but clear of the supports from which the wires are suspended.
When a crossing of clear headway is required the wires may be discontinued for
about the length of the vehicles without breaking the circuit-This system lends
itself easily to making electrical connections round curves and at crossings and
junctions In order to avoid undue vibrations of the wires when necessary I make
the sag of the different wires unequal In some cases I hang some of the wires
from alternate posts to avoid breaking the contact or uneven contacts or undue
vibration. It is sometimes useful to make the supports and insulators capable of
yielding so as to distribute the disturbance caused by a vehicle passing.
It is also sometimes useful to carry the bar or bars on the vehicle on yielding
supports.

page_text: I, JOHN HOPKINSON F.R.S of 4 Westminster Chambers Westminster in the
County of Middlesex do hereby declare the nature of said invention for " IMPROVE-
MENTS IN ELECTRICAL RAILWAYS AND TRAMWAYS," 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 means of making the electric connection of an
electrical railway or tramway between the generating dynamo electric machine and
the motor machine on the tram or car.
According to my Invention I suspend a wire or wires (constituting the conductor
or conductors) from insulated supports above the track and I fix upon the car or
train contact pieces surfaces or rollers to make contact on the under part of the
conductor or conductors In order that the suspended conductor or conductors may
occupy any position over the car or train laterally and proper contact still be
maintained the contact pieces whether they consist of fixed surfaces or rollers aro
extended transversely to the car or train or are arranged to travel transversely to
the car or train The said contact pieces are placed at such a level that they will
pass clear beneath the supports of the suspended conductor or conductors without
touching the same or lifting it or them from the said supports-The advantages of
the overhead conductor or conductors are amongst other advantages that the
conductor or conductors is or are placed out of reach, that the distance between
posts even on curves and at junctions may be considerable, and that minutely
accurate adjustment is not needed as the contact piece on the car may lift the
conductor or conductors as the car or train travels along by nearly the full amount of
the sag of the said conductor or conductors When the contact pieces on the car or train
are extended laterally or capable of moving laterally the necessary freedom is still
more beneficially obtained to allow of considerable distance between the supports
even on curves and there is great ease of working on both curves and junctions and
when the said contact pieces are arranged to pass clear of the insulating supports
of the conductor or conductors these supports may be of a simple and inexpensive
construction.
And in order that my Invention may be thoroughly understood I will more
particularly describe the same with reference to the accompanying diagrams,
whereon figure 1 shows in diagram a side elevation of a part of the line with a
car between two posts Figure 2 is a diagram of the saine shewing a car passing
a post and Figure 3 is an end elevation The conductors a a are carried much as
telegraph wires are carried but special provision is made against the varying tension
of the conductors which arises from the passing cars lifting the conductors above it.
This may of course be effected by using posts fixed with exceptional strength but
when the spans are approximately equal it may be effected by allowing the con-
ductors to be free to slide longitudinally where they are supported by the posts;
bb are the contact pieces on the car fixed in the case sliewn at a considerable
height overhead in order to be out of reach of passengers on the top of the car
and to leave headway under the conductors where other roads cross. Where these
conditions do not exist both conductors and contact pieces may be placed lower.

page_text: Two contact pieces b b are shewn as being placed on the car to enable the contact
to be maintained when the car is passing a post and this is necessary where the
contact pieces on the car or train aro at a lower level than the supports of the
suspended conductors as herein before stated The contact pieces bb may if desired
be rollers to avoid friction and wear and tear but for the reason hereinbefore given
these rollers are also extended across the car to make contact at any point of the
width of the car-It will be evident that instead of making the contact pieces or
rollers continuous transversely across the car or train they may be mounted so
that they can travel transversely along rods or guides extending across the car or
train.
I prefer to use at least two wires as conductors to secure continuous contact even
when the wires vibrate and it is better to stretch them with a slightly differenti
tension so that their normal times of vibration may be different, but I do not limit
myself to the use of two or more wires or conductors as one only may be used.-
Where great uniformity of contact is required the number of posts may be
increased, and the wires or conductors a a be hung from alternate posts as shown
in Figure 4. It will be readily understood that a separate and similarly insulated
return wire or conductor may be provided, but I prefer to use the rails and the
earth as a return, as is well known in connection with known systems of electric
railways and tramways, and in that case the generating dynamo will have one
pole connected to the earth and the other to the insulated conductor a a whilst
the contacts b b are connected by a wire or other conductor to one pole of the
dynamo on the car or train, the other pole of which dynamo is connected
electrically to the wheels of the car or train and so to earth. The Electric circuit
is thus From the generating dynamo through the conductors a, a, and con-
tacts b, b, to the motor dynamo, thence through the wheels of car and the rails to
earth, and thence back to the generating dynamo.
Figure 5 illustrates the application of my Systom to a curve. It will be
observed that at X the contact pieces b, b, make contact near one extremity
whereas at X² they make contact at the other extremity but that the wires or
conductors a, a, are not displaced laterally. Figure 6 illustrates the application of
the Invention to a junction of two lines. In this case also the lateral extension of
the contacts b, b and their being placed at a lower level than the supports of the
wires or conductors a enable, when these conditions are observed, the connection
to be readily maintained at the junction.
In order to keep the headway beneath the conductor or conductors a a constant,
notwithstanding variations of temperature, it is in some cases advantageous to
provide means for taking up the increase of length of the conductor, due to rise
of temperature. This may be effected in various ways. In figure 7 I have shewn
diagrammatically in side elevation a portion of a line provided with an arrange-
ment suitable for taking up the expansion of a comparatively short length of
wire a This consists of a bell crank c, pivotted to the post at d. To this bell
crank the wire is fixed, the tension of the wire being counterbalanced and kept
sensibly constant by the weight e, on the said bell crank. Figures 8, 9 and io
illustrate an arrangement suitable for taking up the expansion of a greater length
of wire a. Figure is a plan. Figure 9 a side elevation and Figure 10 an end
elevation to a larger scale. The end of the wire a is taken round a flanged
pulley f turning on a centre fixed to the post and thence over a second pulley g,
also turning upon centres fixed to the post and the wire is then attached to a
weight h. Whichever arrangement is adopted, means are readily provided for
maintaining the electric continuity of the conductor.
It is unnecessary to shew or describe the arrangement of the dynamo on the car
or train or the mechanism for making or reversing the connections thereof or other
details not essential to the features constituting my Invention, as the said arrange-
ment and mechanism are well understood in connection with other systems of
railways or tramways and may be arranged as has hitherto been customary or in
any other suitable way.

page_text: Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is
First. In electrical railways or tramways a suspended conductor or suspended
conductors arranged to make contact with contact pieces on the car or train
substantially as herein before described..
Second. In electric railways or tramways contact pieces fixed on the car or
train and arranged to make contact with a suspended conductor or suspended
conductors and lift it or them substantially as hereinbefore described.
Third. The combination with an electric train or tramcar of contacts thereon
and a suspended conductor or suspended conductors in contact therewith substan-
tially as hereinbefore described.
Fourth. The combination with an electric train or tramcar of contacts thereon
and a suspended conductor or suspended conductors along the line, the contacts on
the car or train being at such a level relatively with the conductors or conductor
that the said contacts pass clear beneath the supports of the said conductor or
conductors substantially as hereinbefore described.
Fifth. In electric tramways or railways the combination with the car or train,
of a contact piece or contact pieces extended across the car or train or capable of
moving there, across so that in all positions of the car or train proper contact with
the conductor or conductors of the line is maintained substantially as hereinbefore
described.
Sixth. The combination with the car or train of an electric railway or tramway
of a suspended conductor or conductors and contact pieces fixed on the car or train
at such a level as to pass clear beneath the insulating supports of the said con-
ductor or conductors the said contact pieces being extended transversely across the
car or train, or being capable of moving transversely there-across, substantially as
and for the purposes herein before described.
Seventh. In electric railways or tramways, the general arrangement and com-
bination of parts constituting the improved system for adaptation to straight lines
and curves and junctions all substantially as hereinbefore described.
.
DTL
100K