IMPROVEMENTS IN THE CONSTRUCTION OF MOTORS FOR TRAMCARS AND SIMILAR VEHICLES
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Joseph Theodore Dann at the Office
of the Commissioners of Patents on the 26th July 1883. Communicated
to him from abroad by Charles Brown, of Winterthur, in the Republic of
Switzerland
JOSEPH THEODORE DANN, of 32 Canterbury Road, Brixton, in the County of
Surrey, Civil Engineer, "IMPROVEMENTS IN THE CONSTRUCTION OF MOTORS FOR
TRAMCARS AND SIMILAR VEHICLES a communication to me from abroad by
Charles Brown, of Winterthur in the Republic of Switzerland
"
This Invention has for its object to adapt to the requirements of traction on
tramways as well as on ordinary railways, a self-acting mechanical apparatus
taking the place of horses, mules or other animals in front of tramcars or similar
vehicles and combining most of the advantages of animal traction with an entire
absence of all its concomitant drawbacks; among the advantages alluded to being
reckoned the great suppleness and flexibility possessed by various quadrupeds in
acting as motors for vehicular traffic on rail or tramways, and among the principal
drawbacks the vast outlay required, in the shape of plant and working expenses,
for feeding, tending, and stabling the animals referred to, apart from the notoriously
high death-rate prevalent chiefly in the case of tram-horses.
In constructing the motor according to my Invention, I provide one driving axle
upon which the two driving wheels run loose, being compelled by a differential or
other suitable gearing to revolvo along with the axle, thus adapting themselves to
any curve, however small the radius thereof may be; whilst in caso of the radius
of the curve being large, the wheels may be keyed fast on to the axle. Upon the
framework supporting this axle in the customary vehicular manner I mount a
mechanical motor of any appropriate kind actuated by any proper agency, such as
steam, hot water, gas, compressed air or electrical current, together with its
generator in the shape of a steam boiler, a water or air tank, an accumulator, or
any other suitable reservoir of energy. At each end of the engine shaft within
which the power engendered by the prime mover is concentrated, I fix a pinion
which I connect by means of a chain with a wheel fixed at the corresponding
extremity of the wheel axle, such pinions having different diameters, so as to enable
the power produced by the engine to be brought into proper proportion to the work

page_text: to be done on level ground or on ascending or descending a gradient, according as
the case may be; and I furnish the engine shaft with clutches or other suitable
organs by means of which it may be coupled or uncoupled and thrown in or out of
gear at the discretion of the driver. I also fix the engine frame and the generator
at such an inclination towards one another as to admit of their supporting each
other, and this I effect by placing the engine and the reservoir of energy on opposite
sides of the driving axle.
To the framework of the motor I fit a pole sliding within a directing tube
which itself is lodged in a pivoting support or carrier, both the tube and its
support or carrier being connected with the framework of the tramcar or vehicle
that is to be drawn along by the motor or locomotive. In using or employing
this description of coupling between motor and car, I furnish the car itself with
radial axles and with an articulating arrangement consisting of a series of frames
connected together by one or more connecting links, whereby the wheels of the car
are enabled to inscribe themselves correctly within the rails in passing over curves.
When, on the contrary the axles of the car are fixed and parallel to each other,
I so fit the locomotive pole as to have it carried between two parallel bars,
placed in proximity to one of the axles of the car, and bring the weight of the
engine to bear upon a point close to that axle; the pole being guided between two
inclined check-bars and a coupling bar being hinged at one end to the car-frame
and fixed at the other end to the extremity of the pole nearest to the engine; and
a similar arrangement may also be used with articulated cars. In either arrange-
ment the centre of gravity of the whole machine is placed near, but somewhat in
the rear of the wheel axle, so that, when the locomotive is uncoupled, a part of the
weight comes to rest on two small trailing wheels, and owing to the centre of
gravity being thus close the centre of the axle, it is obvious that the engine may
be easily handled by the engine pole in the same way as in any other two-wheeled
vehicle.