IMPROVEMENTS IN GUARDS OR SHIELDS FOR THE WHEELS OF TRAMWAY CARS, OMNIBUSES, AND SIMILAR VEHICLES
Year: 1874

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PROVISIONAL SPECIFICATION left by John Cross Aitken at the Office.
of the Commissioners of Patents, with his Petition, on the 25th
November 1874.
I, JOHN CROSS AITKEN, of Leith, in the County of Mid Lothian,
North Britain, Shipowner, do hereby declare the nature of the said.
· Invention for "IMPROVEMENTS IN GUARDS OR SHIELDS FOR THE WHEELS OF
TRAMWAY CARS, OMNIBUSES, AND SIMILAR VEHICLES," to be as follows, that is
to say:-
This Invention, which relates to improvements in guards or shields for
the wheels of tramway cars, omnibuses, and similar vehicles, has for its
object to prevent or lessen the mutilation of such persons or animals as
may be " run down" by the vehicle to which the said guards or shields
are attached, and consequently to obviate the loss of life attendant upon
such accidents occurring with those cars and other vehicles now in use.
It consists in constructing the guard or shield in a box-like form, having
a closed front projecting in the form of a nose, just clear of the upper
surface of the rails or of the ground upon which the car or other vehicle
travels, and overlapping at back a portion of the wheel of the car or
other vehicle, but not in contact therewith, and having an axle extending

page_text: transversely across its interior, upon which axle is centred a small wheel
or antifriction roller, whose periphery is in contact with the upper
surface of the rails or ground. A link or links are rigidly fixed to the
lateral sides of the guard or shield, or otherwise connected thereto, and
are pivotted at their other ends on the axle of the wheel of the car or
other vehicle. By this means any vertical oscillation of the car produces
no difference in the position of the guard or shield with respect to its
height above the rails, and its projecting nose may thus be allowed to
approach close to the rail, and effectually prevent the contact of any
obstacle human or otherwise with the wheel, and also prevent the
mutilation thereof, as contradistinguished from the rigidly fixed guards
or shields now used, and which from the damage and breakage con-
sequent on the shocks arising from their frequent violent contact with
the rails or ground are placed so high above the latter as to be rendered
inefficient for their purpose and productive of mutilation.
Instead of pivotting the inner ends of the links or connecting rods on
the axle of the car wheel they may be made to work on pins carried in
brackets depending from the side soles of the car frame or other con-
venient place.
Another form of this Invention consists in discarding the links or
connecting rods-and attaching to the guard or shield a vertically sliding
rod working in brackets attached to the car frame, or brake shoe, or
'other suitable place.
By a convenient arrangement of levers or chains the guard or shield
may at will be raised so as to free the antifriction roller from contact
with the surface of the rail or ground, and be so held until required to
be put in use, when it may be lowered by the driver or other person
seeing cause of danger.
It will be understood that the guards or shields arc to be provided at
the front of each of the leading wheels, and to the rear of each of the
trailing wheels of the car or other vehicle.