IMPROVEMENTS IN TRAM CARS
Year: 1878

page_text: PROVISIONAL SPECIFICATION left by Charles Llewellyn Light and Henry
Merryweather at the Office of the Commissioners of Patents on the 10th April
1878.
CHARLES LLEWELLYN LIGHT, of Westminster, in the County of Middlesex, Civil
Engineer, and HENRY MERRYWEATHER, of the Firm of Merryweather and Sons,
Engineers, of Lambeth, in the County of Surrey. "IMPROVEMENTS IN TRAM
CARS."
Our improvements in tram cars have for object to produce light and durable
vehicles, and economise tractive force.
To give strength and rigidity to the car body and prevent "hogging" thereof,
it is constructed with metallic under framing trussed by means of struts and tie rods
arranged longitudinally under the seats. To facilitate starting and reduce the
strain on the horse or other tractive agent, springs and recoil rings are interposed
between the draw bars, and the frame or body, so that in moving the vohicle the
draw bars operate through the springs, and in stopping through the recoil rings.
To allow of endwise movement of the axles (lateral play of the bearings) when
travelling on curved lines, the axle journals are of smaller diameter at or near their
centres than at their respective ends; the diameter increases towards each end; the
bearings are made shorter than the journals, and of corresponding form, so that
when travelling over curves the bearings may be slightly raised by passing up the
inclined surfaces of the journals, and on a straight part of the road being reached
the weight of the carriage body will cause the bearings and axles to automatically
resume their normal relative positions.
To further economise tractive power the wheels are loose upon their axles, between
which and their interior surfaces of the wheel naves or hubs are interposed anti-
friction rollers, kept at suitable distances apart, with their axes parallel to the axes
of the axles they surround by means of carrier plates secured to the naves or hubs
of the wheels.
To enable the vehicle to be readily stopped without undue wear and tear of the
wheel, treads and flanges, metallic strap breaks, or blocks, and actuating gear are
arranged to operate in connection with friction drums or surfaces fixed to or formed

page_text: with one or more of the wheels, or where the wheels are not free to rotate inde-
pendently of the axles the drums may be fixed on the axles; or we so stop the car
as to absorb and store up the power due to the momentum of the car in stopping,
and utilize the power thus obtained in starting the car.
The construction of the apparatus for this purpose is as follows:-A drum of
convenient dimensions is provided, having its interior on one side in the form of a
cone or other friction clutch running loose upon the axle; a second cone or other
equivalent half friction clutch is so fixed as to be capable of sliding on one or more
feathers in the axle. To the drum is fixed a chain or rod in such manner that a
partial revolution of the drum extends or compresses a spring which upon being
released acts upon a larger diameter of the drum on its opposite side, and thus gives
a continuous motion to the drum or rotation in the same direction.
The clutch on being put into gear gently (by means of a handle and rods which
may be similar to those of an ordinary car brake), itself acts as a brake by slightly
retarding the revolution of the axle on which it is fixed. If more force be applied
to the handle the clutch takes firm hold of the drum, and causing its partial revo-
lution, winds up the spring as before described; upon releasing the clutch the drum
is caused to rotate still in the same direction by the means before described, and
causes the wheels to advance on the rails.
A reversing catch is arranged by means of which the apparatus may be set to
work in either direction.
The arrangement may be applied to one or both axles.
The improvements above described may obviously be carried out in various
forms, and it will be evident that some one or more of them may be used without
the others.