Improvements in and connected with the Overhead System of Electric Traction.
Year: 1895

page_text: Date of Application, 3rd Sept., 1895
Complete Specification Left, 3rd July, 1896-Accepted, 8th Aug., 1896
PROVISIONAL SPECIFICATION.
Improvements in and connected with the Overhead System of
Electric Traction.
1. WALTER CHARLES BERSEY, of Grosvenor House, Gore Road, South
Hackney, London, N.E. Electrical Engineer, do hereby declare the nature of this
invention to be as follows:
--
This invention relates to electric traction on tramways by overhead lines and
trolley collectors. The overhead lines comprise line and return wires upon each of
which run trolleys constructed of a jointed toggle or diamond-shaped frame in
which are mounted three grooved travelling wheels, one at each end bearing
upwards against the wire and an intermediate one at upper middle joint bearing
downwards upon the wire, the pressure in opposite directions of the end and middle
wheels being maintained by a spring tending to draw the two middle joints of the
diamond frame together. Thus arranged the centre of gravity of the trolley is
below the wire on which it runs so that overturning of the trolley is prevented.
The wheel spindles are mounted to rotate in the frame and are tubular and closed
at the ends to form oil reservoirs from which oil is supplied through an oil hole to
the bearing surfaces of the spindle. At the supporting posts the wire is connected
to bifurcated ridges or bars, one member passing above and the other below the
supporting bracket in an acute diamond form, the jointed and spring action of the
diamond-shaped trolley frame enabling it to expand in the vertical direction to
permit of the upper and lower sets of wheels passing above and below the
bracket.
Dated this 3rd day of September 1895.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.
COMPLETE SPECIFICATION.
Improvements in and connected with the Overhead System of
Electric Traction.
I, WALTER CHARLES BERSEY of Grosvenor House, Gore Road, South
Hackney, London, N.E. Electrical Engineer, 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 relates to electric traction on tramways by means of overhead
lines and trolley collectors.
The invention consists essentially in the means whereby the trolley wheels are
caused to bear with constant pressure upon the wire so as to ensure continuous
contact and avoid jumping and sparking and whereby they are adapted to pass the
points of support of the wires, and it also consists in the mode of supporting the
wire so as to ensure continuous unbroken contact of the wheels therewith.
The invention will be described with reference to the accompanying drawings
forming part of this specification wherein Figure 1 is a side elevation shewing

page_text: the trolley in its normal position on the wire. Figure 2 is a similar view shewing
the trolley passing a point of support, Figure 3 is a cross-section at the point of
support and Figure 4 is an enlarged axial section of one of the wheels of the
trolley.
The trolley collector is preferably constructed of a toggle like frame composed
of the four members a a a a jointed together at so as to permit of the frame
assuming a more or less acute diamond shape. At the three joints b¹² bare
mounted the spindles of three grooved wheels c¹ c² 3 of which the intermediate
wheel and the extreme wheels hear in opposite directions against the wire
conductor d the former bearing in the downward, and the latter in the upward,
direction. The mutually opposing pressures of the wheels is maintained by a
spring e connected to the two middle joints 636 and tending to draw them together.
The wheels are situated at or overhang from one side of the frame so as to permit
of the latter passing the wire supporting brackets, but as by the arrangement
described the centre of gravity of the trolley is below the level of the wire the
trolley is not liable to overturn.
lustead of the jointed frame it will be evident that the opposing pressures of
the wheels on the wire might be obtained by mounting the wheel spindles in
blocks fitted to slide in guide slots in a rigid frame, the slide blocks of the
intermediate and extreme wheels being pressed in opposite directions by springs.
At the supporting posts the wire d is connected to rails passing above and
below an acute diamond insulated bracket g bolted or otherwise fixed to the post h.
The wheels being spring pressed towards the wire are capable of separating in the
vertical direction either by the jointed construction of the frame or by the sliding
of the spindles in their guides so as to permit of the upper and lower sets of wheels
passing respectively above and below the bracket as shewn without at any time
ceasing to maintain contact with the wire so that no sparking can occur.
The spindles of the trolley wheels are made tubular and closed at the ends so
as to serve as receptacles for oil to be supplied through a hole i to the bearing
surfaces of the wheels, which run loose on the spindles. The latter may either be
themselves the joint pins of the frame a or they may be fixed in tubular joint pins.
To the spindle of the joint of the trolley is connected a flexible conductor j led
down through a guide tube rising from the roof of the car, to the motor, there
heing two such trolleys in the case of a line and return wire circuit, or only one in
the case of a rail and earth return.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed 1 declare that
what claim is :-
1. A trolley collector for overhead conductors having three wheels pressed by
mutually opposing spring pressures against the wire, so as to maintain constant
contact and perinit of separating to pass the wire supports substantially as
specified.
2. The herein described expanding trolley collector consisting of a jointed frame
and three wheels pressed by inutually opposing spring pressures against the wire
substantially as specified.
3. In an overhead system of electric traction, the conductor bifurcated so as to
pass at opposite sides of a support of elongated acute form in combination with a
trolley collector having wheels oppositely pressed against the wire and adapted to
pass at opposite sides of the said support substantially as specified.
Dated this 3rd day of fl. 1906
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.