Improvements 155 the Draft of Tramway and other Vehicles.
Year: 1887

page_text: Improvements
155
the Draft of Tramway and other Vehicles.
I, CHARLES WRIGHT PEARSALL of Syracuse, in the County of Onondaga and State of
New York, United States of America, Mechanic, do hereby declare the nature of my
invention for IMPROVEMENTS IN DRAFT REDUCERS FOR VEHICLES and in what manner
the same is to be performed to be particularly described and ascertained in and by
the following statement:-
The object of my invention is to produce an improved device for reducing the
amount of draft required to move, from a standstill, and keep in motion any kind of
wheeled vehicle carrying a load.
And it consists in general, of a device for applying the drafts strain to the top of one
or all of the main wheels, applying such draft in such a manner as to effect a frictional
pull upon the periphery of the main wheel, to which it is applied, at a point which is
farthest from the centre of said wheel, and vertically above its axle, such friction
being increased by shifting the weight of the vehicle and the load, from the main
axle to the periphery of the main wheel or wheels.
In the annexed drawing, Fig. 1 is a side elevation of a car truck embodying my
invention, and Fig. 2 is a vertical transverse section on line in Fig. 1.
It is constructed as follows :-A represents the bed frame of a car, which car is shown
to illustrate the principle of my invention, not limiting myself to its application to
that class of vehicles alone.
In its use upon the car shown it operates as a car starter, as the car is started and as
a draft reducer as soon as the car receives headway.
The frame A consists of the side timber, 1, and 2, and the ends 3, and also the box
frames 4, 4, secured to under side of timber, 1.
The inner faces of these box frames are grooved vertically to receive a tenon on each
side of the box 5, so that the box can slide up and down therein. Across the lower
ends of these box-frames, I also secure a stop bar 6, to hold the boxes within the
frames.

page_text: In these boxes 5, I journal the main axles 7, which axles carry the main wheels 8,
the wheels and axles being of ordinary construction.
Upon the under side of the side timber 1, and 2, I secure journals 9, receiving the
supplemental axles 10, upon which I mount the supplemental, or as I term them, the
"draft-wheels," all being so erected that the peripheries of the draft-wheels rest in
close frictional contact with the peripheries of the tread of the main wheels.
It will be observed that the draft wheels are much smaller than the main wheels.
It will also be observed that the weight of the vehicle and load is supported
entirely upon the peripheries of the main wheels, being in one sense carried by the
draft-wheels and also that such weight effects the strongest or maximum frictional
contact of the draft wheels upon the main wheels.
It will be further observed that when strain or draft is applied to either end of the
frame A such draft operates directly upon the periphery of the main wheels, and
exerts greater pulling power, than if applied to the main axles 7, proportional to the
distance such strain is removed from the centres of the main wheels.
As the boxes are free to play somewhat vertically in their frames I can interpose
springs 12, between the boxes and the frame, and can make those springs strong
enough to carry the weight of the body of the vehicle and support it in such manner,
when empty, as to prevent very much frictional contact of the draft-wheels upon the
main wheels.
Also the main wheels can be mounted loosely upon the main axles, to permit
independent revolution of the wheels in each pair, in turning a curve.
. Having now particularly described and ascertained the nature of my said invention
and in what manner the same is to be performed, I declare that what I claim is :-
1. In combination with the frame of a vehicle, a main wheel having bearings to
admit vertical play in said frame, and a draft wheel resting on the tread of said
main wheel and having its bearings under the frame to support the load, substantially
as described.
2. The combination with the frame of a vehicle of a main wheel having bearings to
permit vertical movement in said frame, a draft wheel resting on the tread of the main
wheel and supporting the frame on its bearings and relieving springs interposed
between the bearings and the frame, substantially as described.
3. The combination with the frame A having box frame 4, of the main wheels 3,
having axle bearings 5, guided to vertical movement in said box frame, draft
wheels 11, resting on the tread of the main wheels perpendicularly above their
centers and having their bearings in the frame at each side of a perpendicular extension
of the main wheel, and springs 12, above the movable bearings of the wheels, all
substantially as described.
CHARLES WRIGHT PEARSALL.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.