IMPROVEMENTS IN AND CONNECTED WITH TRAMWAY CARRIAGES
Year: 1874

page_text: PROVISIONAL SPECIFICATION left by John Hornsby Carruthers and
David Rankine at the Office of the Commissioners of Patents, with
their Petition, on the 2nd April 1874.
We, JOHN HORNSBY CARRUTHERS and DAVID RANKINE, of Glasgow,
in the County of Lanark, North Britain, Engineers, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN AND CONNECTED WITH
TRAMWAY CARRIAGES," to be as follows, that is to say :-
.
―:
'This Invention relates to improvements designed to overcome certain
difficulties and defects found to exist in the system of tramways and
tramway carriages, which has become prevalent of late years, the
difficulties and defects referred to causing greater friction than was to bo
expected, and thereby necessitating excessive hauling power and greatly
increasing the wear and tear of the trams and carriages, particularly as
regards the wheels and axles of the latter and the connections of these
with the carriage framing.

page_text: A feature of the present tramways in which they differ from ordinary
railways, and which seems to have been commonly overlooked, is the
main cause of the difficulties referred to, and that is the having a raised
part of the tram on each side of the wheel flange (the tram being formed
with a groove in which the flange runs between two raised sides). In a
common railway when the flange of one wheel of a pair on the same
axle is pressed against its rail, the flange of the other wheel is necessarily
freed from its rail, but with the tramway a lateral pressure causes both
wheel flanges to be pressed, one against the outer side of its groove, and
the other against the inner side of its groove. There is thus much
greater friction in the case of the tramway, and this becomes worse
where the line is at all curved or where the wheels or line are out of
gauge, or when, as must frequently happen, even on a straight line, there
is the slightest tendency in the carriage to assume an oblique position or
to move laterally.
By the present Invention difficultics such as are hercin-before
indicated are overcome by arranging the wheels on one side of the
carriage, so as to be independent of those on the other side without
making them loose on their axles, which would be merely substituting
some evils for others. For this purpose each single wheel is fixed on a
separate axle of its own, and the axle of each wheel extends from the
side on which its wheel is across the carriage framing to the other side,
being by preference tapered from the wheel end to the other end, and
having bearings at or near each end. With this arrangement¸ the
individual wheels of each transverse pair will be so far out of line as
that the two axles may pass and lie parallel to each other. When the
wheels are situated outside of the side beams of the carriage framings,
the bearings for the inner ends of the axles may be directly attached to
such side beams, and when the wheels are inside of the side beams, the
bearings last referred to can either be attached to brackets, or the two
axles may be arranged sufficiently apart longitudinally for cach to pass
outside of the wheel of the other, so as to reach the further side beam.
In order to render the wheels on each side still more independent of
those on the other side, their bearings may be fitted so as to be capable
of a limited lateral movement, or one wheel of cach pair, may be made 3
with a flange and the other without, whilst in arranging two or more
pairs of wheels on a carriage the flanged wheels may be put all on one

page_text: side, or the flanged and unflanged wheels may be disposed alternately on
each side.
The application of the herein-before described improvements to
existing tramway carriages will render the hauling of them, particularly
on slight inclines and on curves, much less severe on the horses than is
at present the case.