IMPROVEMENTS IN THE CON- STRUCTION OF RAILWAY VEHICLES."
Year: 1879

page_text: LETTERS PATENT to Robert Francis Fairlie, of Victoria Street, in the City of
Westminster, Engineer, for the Invention of "IMPROVEMENTS IN THE CON-
STRUCTION OF RAILWAY VEHICLES."
PROVISIONAL SPECIFICATION left by the said Robert Francis Fairlie. at
the Office of the Commissioners of Patents on the 5th March 1879.
ROBERT FRANCIS FAIRLIE, of Victoria Street, in the City of Westminster,
Engineer. "IMPROVEMENTS IN THE CONSTRUCTION OF RAILWAY VEHICLES."
My Invention has special reference to six wheeled vehicles, and its object is to
enable the wheels and the bogie frames or trucks which carry them to adapt
themselves in a better manner than bitherto to curves of the line without imparting
their swivelling movement to the body of the vehicle.
For this purpose I employ for each vehicle three bogie or swivelling trucks, each
provided with a single pair of wheels; these trucks are connected together by
diagonal or other suitable couplings, and support a rigid frame or carrier upori
which the body of the vehicle is mounted. Each of the trucks has a bogie centre
to receive a pin preferably of large diameter on the rigid frame, but the middle
truck instead of having a simple "centre" to turn or swivel on the pin is formed with a
transverse slide or groove, which is free to travel along the pin in accordance
with any side-long movement imparted to the truck by the construction of the
line, the truck being nevertheless free to turn on the said pin. Each truck is
formed at each end with a curved slot struck from the bogie centre, and the rigid
frame is provided with pins to take into these curved slots, so that each of the
trucks is free to swivel independently without affecting the movement of the rigid
frame.
The bogie pin on the rigid frame of the middle truck, instead of working in a
transverse slide or groove as before described, may if desired take into a circular
hole in a transverse slide which works in a transverse guide or channel in the said
truck.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Robert Francis -Fairlie-in-the-Great -Seal Patent Office on the
5th September 1879.
ROBERT FRANCIS FAIRLIE, of Victoria Street, in the City of Westminster,
Engineer. "IMPROVEMENTS IN THE CONSTRUCTION OF RAILWAY VEHICLES."
My Invention has special reference to six wheeled vehicles, and its object is to
enable the wheels and the 'bogie frames or trucks which, carry them to adapt
themselves in a better manner than hitherto to curves of the line without
imparting their swivelling movement to the body of the vehicle.
For this purpose I employ for each vehicle three bogie or swivelling trucks,
each provided with a single pair of wheels; these trucks are connected together by
diagonal or other suitable couplings, and support a rigid frame or carrier upon
which the body of the vehicle is mounted. Each of the trucks' has a bogie centro
to receive a-pin, preferably of large diameter, on the rigid frame, but the middle
truck instead of having a simple "centre" to turn or swivel on the pin, is formed
with a transverse slide origroove which is free to travel along the pin in accord-
ance with any side-long movement imparted to the truck by the construction of
the line, the truck being nevertheless free to turn on the said pin. Each of the
outside trucks is formed -at-each-end-with-a-curved -slot-struck from the bogie
centre, and the rigid frame is provided with pins to take into these curved slots, so
that while each of the trucks is free to swivel independently without affecting the
movement of the rigid frame, the swivelling movementlis properly controlled.
The bogie pin on the rigid frame of the middle truck, instead of working in a
transverse slide or groove. as before described, may if desired take into a circular
hole in a transverse slide which works.in a transverse guide or.channel.in the said
truck,
The manner in which 'I prefer to carry my Invention into effect is shown in the
annexed Drawings. Figure 1 is a side elevation of the vehicle; Figure 2 is a plan
of the three bogie trucks; Figure 3 is a central longitudinal section of the middle
truck; and Figure 4 a transverse section of the same truck.
A, B, C, are the three bogie trucks, each provided with a single pair of wheels
as shown and connected by diagonal couplings D, D. E (Figure 1) is a rigid
frame or carrier upon which the body F of the vehicle is mounted, and which is
itself supported by the bogie trucks A, B, C. Each of the trucks has a bogie
centre H to receive a pin on the rigid frame E; these pins I prefer to be of large
diaméter, particularly that for the middle truck B. The middle truck'is formed as
before described with a transverse groove or slide K, which is free to 'travel along
the pin I in accordance with any side-long movement imparted to the carriage.
The pin I is rounded as shown to allow either of the wheels of the middle truck to
rise or fall in going round sharp curves. The part L of the frame E-does not quite
touch the truck, so that a little freedom'is, allowed for the rise or fall just men-
tioned, and india rubber or other elastic material faced with metal may be placed
between the frame E and the truck at N if thought desirable. The trucks A and
Care formed at each end with a curved slot M struck from the bogie ‘centre, and
the rigid frame E has pins to take into these slots as herein before described.
And having now described the nature of my said Invention and in what manner
the same is to be performed, I declare that I claim :-
First. Constructing six wheeled vehicles with three bogie or swivelling trucks,
the middle truck being capable of swivelling as well as moving transversely of the
vehicle, substantially-as-and-for-the-purpose-herein before-described, and represented
in the annexed Drawings.

page_text: Second. Constructing the trucks A and C with curved slots M to receive pins on
the frame E, substantially as and for the purpose herein before described, and
represented in the annexed Drawings.
In witness whereof, I, the said Robert Francis Fairlie, have hereunto set
my hand and seal, this Third day of September, One thousand eight
hundred and seventy nine.
ROB³. F. FAIRLIE. (L.S.)