VEHICLES FOR TRAMWAYS AND RAILWAYS."
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by Martyn John Roberts at the Office
of the Commissioners of Patents on the 21st June 1877.
MARTYN JOHN ROBERTS, of the City of Bath, Esquire.
VEHICLES FOR TRAMWAYS AND RAILWAYS."
"IMPROVEMENTS IN
The objects of my Invention are, to enable all or any desired number of the
wheels of a tramway train, or the wheels of a railway locomotive, tender, and
adjoining vehicle or vehicles to be driven from the engine whatever curves there
may be in the line. Also to so connect or couple the vehicles, or the bogies on
which they are mounted, to the tramway or railway locomotive, or to each other,
or a bogie beneath a carriage to any axle on that carriage, that they may readily
adapt themselves to any curves of the line, and to the mode of driving the wheels
above referred to, at the same time allowing of a short rigid wheel base for such
vehicles.
I will proceed to describe my Invention as applied to tramway vehicles, for
which it has been specially designed, but it will be readily understood that the
improvements will also be found advantageous when applied to vehicles for
ordinary railways.
In order to drive all or a number of the wheels of a tramway train I first drive
one pair of the wheels of the steam car from the engine in any usual manner, and I
connect the axle of these wheels, or the axle of another pair of wheels driven by it,
with the axle of another pair of wheels of the next adjoining vehicle or bogie by
means of a connecting rod, which is free to move horizontally on a centre, situated
at a point which is at or near the centre of the axle of the driving pair of wheels.
This rod is attached to either or both of the axles, which it connects by means of a
universal joint, so that no matter what may be the obliquity or inclination to each
other of the two axles, produced by curves of the line, the driving of the second axle
from the first by means of the connecting rod can be effected. The universal joint
which I prefer for the purpose consists of a tube or collar fitted upon a crank or
excentric on the axle, and free to turn around the crank, and on this tube are a
pair of pins, transverse to the axis of the tube, to which pins are jointed or pivoted
the prongs of a fork or "jaws" on the end of the connecting rod. Thus while the
rod can move horizontally as required by curves in the line by the motion of the

page_text: fork on the pins the rod receives from the revolution of the crank the necessary to-
and-fro motion which it transmits to a corresponding crank on the other axle, the
loss of power on the sharpest curves of tramways being so slight as to make no
appreciable difference.
น
Instead of cranked axles and connecting rods pulleys, ropes, and straight axles
may be used, but I prefer the cranked axles and connecting rods, the main principle
to be maintained being that in any angular motion of the one axle to the other
the centres of the driving and the driven axles shall not be placed at different
distances from each other at different times of movement.
For the purpose of enabling the vehicles, or the bogies on which they are
mounted, to readily adapt themselves to the curves of the line, and also to coincide
in angular motion with that of the connecting rod, I connect or couple adjoining
vehicles together at a point which is in the same vertical plane, or as nearly so as
practicable, as the joint of the connecting rod before described, so that the centre of
the horizontal motion around each other of two adjoining vehicles or bogies is the
same, or nearly so, as the centre of horizontal motion of the rod which connects the
cranked axles. Thus whatever angular motion is imparted to the vehicles by the
curve of the line it is the same as that given to the connecting rod.
In the case where the vehicle which carries the driven axle is long I sometimes
partly support it at one end by the coupling which connects it to the vehicle on
which the driving power is placed; or if two or more passenger carriages are in the
train, then one may partially be supported by another. The said coupling may be
made by bars, or a solid platform, or be otherwise made of sufficient strength for
the purpose, and it must be fixed to the centre of horizontal motion above referred
to. By thus supporting one end of a long vehicle the two pairs of wheels of such
vehicles may be placed very near to each other, say, not more than 3 feet apart; the
rigid wheel base being so short the vehicle can run round a very sharp curve. One
pair of wheels of the rigid wheel base may be driven from the other by cranked
axles, or by side connecting rods, or otherwise.
If the coupling before mentioned be made strong enough a single pair of wheels;
on the vehicle may be sufficient.