IMPROVEMENTS IN ELECTRICAL RAILWAYS AND TRAMWAYS
Year: 1883

page_text: LETTERS PATENT to William Acheson Traill Civil Engineer, of Portrush in
the County of Antrim for an Invention of IMPROVEMENTS IN ELECTRICAL
RAILWAYS AND TRAMWAYS
PROVISIONAL SPECIFICATION left by the said William Acheson Traill at
the Office of the Commissioners of Patents on the 2nd July 1883.
WILLIAM ACHESON TRAILL, Civil Engineer of Portrush in the Country of Antrim,
"IMPROVEMENTS IN ELECTRICAL RAILWAYS AND TRAMWAYS."
My Invention relates to improvements in that system of electrical tramways or
railways wherein a metallic brush carried by the car makes contact with an electric
conductor alongside the railway or tramway in order to convey the current to the
electric motor on the car and my Invention has for its object to avoid damage which
is now liable to occur in travelling in alternate directions but more particularly in
passing interruptions in the continuity of the conductor, and secondly to avoid
liability of passers-by receiving electric shocks by coming into accidental contact
with the conductor.
To enable the contacts to more easily travel in either direction along the clectric
conductor and to automatically adjust themselves to such movements and to avoid
the liability of their being broken off or damaged on again striking the conductor
after passing a gap therein, I employ in lieu of the said brushes a double curved
elliptic or semi elliptic spring attached to the projecting arm from the car and
furnished with a shoe or contact wearing piece which moves along the conductor
the inclined surface of the elliptic brush more readily rising up upon the bevelled
end of the conductor. The shoe may either be a solid block having bevelled edges
or it may have a pointed or brush like contact surface or be composed of a number
of small springs secured at both ends or otherwise attached.
To accomplish the second object of my Invention I suspend the insulated
conductor below suitable supports and enclose or cover the top and sides of the
conductor with a non conducting material, the contact shoe being applied to the
underside of the conductor. The ends of the conductor would in this case be turned
up instead of down where gaps occur to facilitate the passage of the contact shoe
from one to the other.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Acheson Traill in the Patent Office on the 2nd January
"
1884.
WILLIAM ACHESON TRAILL Civil Engineer of Portrush in the County of Antrim
IMPROVEMENTS IN ELECTRICAL RAILWAYS AND TRAMWAYS."
My Invention relates to improvements in that system of Electric Tramways or
Railways wherein a rigid electrical conductor is laid alongside the railway or
Tramway and conveys the electricity from the generator, and where a metallic
contact brush carried by the car makes contact with such electric conductor in
order to convey the electricity to the electric motor in the car, and my invention
has for its object 1st. To collect the electricity from the conductor with the least
possible chances of a break in the metallic contact, to avoid damage to the "contact
brushes" in being rapidly rubbed along the conductor when travelling in either
direction, and more particularly where interruptions in the continuity of the
conductor take place, as at field or road gaps, to avoid. damage to such contact
brushes in passing across such openings. 2nd To minimise the liability of
passers-by receiving electric-shocks by coming into accidental contact with the
conductor.
To enable the contact brushes to preserve continuous contact with the conductor
two or more such contact brushes are generally used, placed at the ends of the
electric cars at a wider distance apart than the length of the gaps of the ordinary
interruptions in the Conductor, or on separate cars. According to my inven-
tion to enable the contact brushes to travel along such conductor with the
least amount of friction, while preserving metallic contact, and to adapt
themselves to the varying loads in the cars, and to automatically adjust
themselves for either direction of motion, and to readily slide off, and again to
imount on to the electric conductor where interruptions of the same occur with the
least chances of breakage, I employ in lieu of and in preference to either metallic
wire brushes or roller wheels, "a contact brush," which in its simplest form is a
double curved elliptic or semi-elliptic steel spring, shaped like a carriage spring.
formed of thin but broad spring steel in one or more leaves, and furnished with a
shoe or contact wearing piece, at the place of rubbing contact. The brush is
attached to a metallic arm projecting from the side of the car and capable of sliding
in or out, being held by a spring catch or screw when drawn out to the requisite
distance, or of folding up.or back when not in use.
Figures 1 and 2 represent a usual form of my contact brush where A and A¹ are
the two parts of the spring, B the projecting metallic arm passing through metallic
slides attached to the car but insulated therefrom, and held in position by the
spring catches or screws D. The brushes are attached to the projecting arm by
bolts and nuts for ready interchange if so required. G is the steel wearing, shoe
attached at the side where the rubbing contact occurs. Figure 3 shews another
shape of brush. The inclined surface-ends of the elliptic brush admit of the brush
more readily rising up on the bevelled ends of the conductor where interruptions of
continuity occur, without causing a violeut blow and for sliding off the bevelled
ends without straining the brush.
The brush is capable of attachment to the projecting arm so as either to press
down upon the top surface of a conductor rail as in figure 2 or so as to press
upward against the under side of a conductor rail as in Figure + or it may be used
for a side pressure.
With the object of preventing the brush expanding too widely when passing
through a gap in the conductor or for the purpose of raising the brush entirely off
the conductor, I connect to the inside of the shoo a short length of chain which is
attached to the end of a screw E adjusted by means of a nut F with insulated
handle, whereby too great expansion of the spring is prevented when passing
through gaps under a heavily loaded car.

page_text: To accomplish the second object of my invention viz: to minimise the chances of
passers-by receiving electric shocks by coming into accidental contact with the
conductor, I suspend the insulated conductor below suitable supports and enclose
or cover the top and sides of the conductor with a non-conducting material.
A suitable application of this mode of construction is where a Tramway is laid
alongside an esplanade or path, where it is advisable to separate such path from
the roadway by a post and rail fence, and where an exposed conductor would be
objectionable. Figure 5 gives a general view of the system adopted where H is
the electric tramcar or carriage and I the pillars of a post and rail fence from
which brackets J project which hold suspended the rigid conductor K, along the
underneath side of which is carried the metallic conductor with which the contact
brush (as above described) makes contact by pressure upward of the brush.
Figure 8 gives an enlarged sketch of the conductor and its supports. The
columns I may be of iron, wood or other material with or without connecting bars
or chains. Brackets J support the conductor K, which is composed of two portions
a non-conducting material L such as wood formed with bevelled edges or rounded
so as to throw off moisture, and a conducting material M either iron or other metal,
but by preference a continuous broad ribband of copper screwed on to the underside
of the non-conducting (wooden) cap with intervening piece of india rubber, gutta
percha, or other insulating material between; the contact brush A would in such a
case press up against the under side of the conductor K. Figures 6 and 7 shew the
disposition of the posts and the conductor, Where interruptions in the continuity
of the conductor would have to be made the ends of the conductor would be turned
up and not down, and insulated conducting cables would be carried down the posts
and underground across the gaps so as to preserve the continuity of the current, as
shown at N figure 6.
The non-conducting material on the top of the metallic conductor would prevent
any casual contact with it by passers-by and so largely tend to do away with the
objections to an exposed conductor.
·
In each case the electric current would be taken from the metallic arm holding
the contact brush and led into the dynamo in the car, the return carrent passing
back through the wheels and rails to the generator.
Having described the nature of my Invention and the manner of performing the
same, I declare that what I claim as my Invention to be protected by the herein-
before in part recited Letters Patent is.
•
1st In a system of electrical tramway or railway wherein the car carries one
or more metallic contact makers which rub against an electric conductor, the
employment of a contact maker constructed of an elliptic or bowed spring furnished
with a shoe or wearing piece on its convex surface which is adapted to come in
contact with the conductor, substantially as herein described and shown in the
drawings for the purpose specified.
2nd In a system of electrical tramway or railway wherein a laterally projecting
contact inaker carried by the car rubs against an electrical conductor mounted
alongside of the track; the mode of mounting said conductor by placing it at the
underside of an insulating supporting and covering rail carried by brackets and of
applying the contact maker to press upwards against said conductor, substantially
as herein shown and described for the purpose specified._
In Witness whereof I the said William Acheson Traill have hereunto set my
hand and seal this twenty eighth day of December, A.D. 1883.
WILLIAM ACHESON TRAILL. (L.S.)