IMPROVEMENTS IN ROLLING STOCK FOR RAILWAYS AND TRAMWAYS
Year: 1871

page_text: PROVISIONAL SPECIFICATION left by Saint John Vincent Day at the
Office of the Commissioners of Patents, with his Petition, on. the
21st June 1871.
I, SAINT JOHN VINCENT DAY, of Glasgow, in the County of Lanark;
North Britain, Civil Engineer, do hereby declare the nature of the said
Invention of "IMPROVEMENTS IN ROLLING STOCK FOR RAILWAYS AND TRAMWAYS,"
to be as follows, that is to say :—
This Invention, which relates to improvements in the rolling stock
used on railways and tramways, has for its essential object the obtain-
ment of greater steadiness and safety when running in vehicles or
engines carried upon a flexible wheel base than obtains under the
arrangements of flexible wheel base hitherto used, one of which arrange-
ments consists in carrying a pair of wheels on an axle in a truck near
to each end of the vehicle, each such truck being attached to the body
of the vehicle by a pivot or pin whose axis is at or near to the centre of
the axle, so that the axle with its truck may swivel thereon in order
-

page_text: to radiate the axle conformably to the contour of the rails on which
the vehicle travels, equal and contrary radiations of the two axles of
each wheel being produced by the well-known method of cross ties or
chains or reverse motion linkwork.
.
According to the arrangement of flexible wheel base constituting
this Invention the vehicles are carried on a pair of "castor trucks" so
that the point at which the castor trucks are coupled to the body
of the vehicle is removed to a considerable distance from (in place of
its axis being at or near to) the centre of the axle of each truck, and
one result of this arrangement is that the body of the vehicle con-.
stantly bears upon three points in each truck, namely, at the part on
which the truck radiates, and at two other points on the opposite side
of each truck, thereby avoiding the oscillations and disturbances which
accompany the arrangement herein-before referred to, wherein the axis
of the pivot is situated at or near to the centre of each axle. The
castor trucks are coupled by either cross ties, chains, or reverse motion
linkwork to produce the equal and contrary radiations, and by means
of the lead due to the position of the radiating centre of the "castor
truck" the contour of the rails of the railway or tramway is sufficient
to maintain the axles normal to the curve or at right angles to the
straight part of the rail without using springs or other contrivance to
aid, the movement of the radiating system. It is preferred to attach the
pivots or pins on which the "castor trucks" swivel (in the case of railway
vehicles) to the buffer beams, and in the case of tramway vehicles to
the end framing beams, but they may also be fixed to other beams so
As to remove the swivelling points from the ends of the vehicles if in
any case desired. In the case of tramway vehicles the draw polo may
be simply hinged either to the swivelling truck or to the body of the
carriage, and it may be connected by catch chains stretching angularly
from the sides of the pole to points at or near to the corners of the
"castor trucks" so as to aid in swivelling them; by this means the
horses in drawing the vehicles may be caused to aid in the radiation of
the castor trucks, the catch chains may also be dispensed with. In
place of fixing the pole to the vehicle by a hinge joint it may be rigidly
fixed to the truck. A brake is provided either on one or both of each
pair of combined castor trucks, which can be operated from either
end of the vehicle, either by turning a handle or raising or depressing
a lever.

page_text: Under this Invention the arrangement herein-before described may
also be combined into a wheel base constituting a pair of four wheel
articulated castor bogies or trucks either acting independently or inter-
coupled, in which case the vehicle would be carried upon four pairs of
wheels.