IMPROVEMENTS IN, LOCOMOTIVE CARRIAGES FOR TRAMWAYS OR COMMON- ROADS
Year: 1874

page_text: LETTERS PATENT to William Dundas Scott-Moncrieff, of Glasgow,
in the County of Lanark, North Britain, Engineer, for the Invention
of "IMPROVEMENTS IN, LOCOMOTIVE CARRIAGES FOR TRAMWAYS OR COMMON-
ROADS."
Sealed the 4th September 1874, and dated the 10th March 1874...
PROVISIONAL SPECIFICATION left by the said William Dundas Scott-
Moncrieff at the Office of the Commissioners of Patents, with his
Petition, on the 10th March 1874.
L
I, WILLIAM DUNDAS SCOTT-MONCRIEFF, of Glasgow, in the County
of Lanark, North Britain, Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN LOCOMOTIVE CARRIAGES FOR TRAMWAYS
OR COMMON ROADS," to be as follows, that is to say :-
This Invention relates to improvements: in the construction and
arrangement of locomotive carriages for tramways or common roads, and
comprises important arrangements and mechanism for using compressed
air as the motive agent in a safe, convenient, and satisfactory manner.

page_text: The air compressed by fixed engines at convenient stations is admitted
into and stored in a strong receiver which is by preference made with a
shell of sheet steel and with sufficient internal stays of steel. In general
contour the receiver is of an oblong rectangular form in plan and of a
uniform or varying depth, and by preference constitutes the lower part
of the body of the carriage, and the internal stays are by preference in
the form of rectangular frames rivetted or bolted to all sides of the
receiver, whilst stay plates connect the ends of the receiver to the sides
of it. A space or well is formed in the middle of the receiver, in and
above which space or well a pair of inverted cylinder engines is arranged
to drive a cranked axle with driving wheels.
The engines are fitted with link motion or other suitable reversing
valve mechanism and with separate adjustable cut-off valves, and in
order to attain uniform working notwithstanding the gradually decreasing
pressure of the air in the receiver the cut-off valve mechanism is adjusted
in accordance with the pressure in a simple automatic manner.
The compressed air is admitted to one end of a cylinder having in it
a piston pressed against the air by a spring, and a rod from the piston is
connected to the adjusting gear so that the air will be cut off early in
each stroke when in its more compressed state, and gradually later and
later in the stroke as its pressure decreases.
In addition to the driving wheels herein-before referred to the carriage
is supported on two other pairs of wheels, one pair at or near each end,
and each pair arranged on a bogie or swivelling frame to facilitate the
passage of the carriage over curves.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Dundas Scott-Moncrieff in the Great Seal
Patent Office on the 10th September 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
DUNDAS SCOTT-MONCRIEFF, of Glasgow, in the County of Lanark, North
Britain, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Tenth day of March, in the year of

page_text: our Lord One thousand eight hundred and seventy-four, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said William Dundas Scott-Moncrieff,
Her special licence that I, the said William Dundas Scott-Moncrieff,
my executors, administrators, and assigns, or such others as I, the
said William Dundas Scott-Moncrieff, my executors, administrators,
and assigns, should at any time agree with, and no others, from time
to time and at all times thereafter during the term therein expressed,
should and lawfully might make, use, exercise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN LOCOMOTIVE CARRIAGES
FOR TRAMWAYS OR COMMON ROADS," upon the condition (amongst others)
that I, the said William Dundas Scott-Moncrieff, my executors or
administrators, by an instrument in writing under my, or their, or one
of their hands and scals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Scal Patent Office
within six calendar months next and immediately after the date of the
said Letters Patent.
NOW KNOW YE, that I, the said William Dundas Scott-Moncrieff;
do hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement in writing, reference being had to the
accompanying Drawings, that is to say :-
My said Invention relates to improvements in the construction and
arrangement of locomotive carriages for tramways or common roads, and
comprises important arrangements and mechanism for using compressed
air as the motive agent in a safe, convenient, and satisfactory manner.
The air compressed by fixed engines at convenient stations is admitted
into and stored in a strong receiver made by preference with a shell of
slicet steel and with sufficient internal stays of steel. In general contour
the receiver is of an oblong rectangular form in plan and of a uniform
or varying depth and constitutes the lower part of the body of the
carriage. A space or well is formed in the middle of the receiver in and
above which space or well a pair of inverted cylinder engines is arranged
to drive a cranked axle with driving wheels.
The engines are fitted with link motion or other suitable reversing
valve mechanism and with separate adjustable cut-off valves, and the

page_text: cut-off valve mechanism is adjusted in accordance with the gradually
decreasing pressure of the air in a simple automatic manner..
And in order that my said Invention and the manner of performing
the same may be properly understood, I hcrcunto append a Sheet of
explanatory Drawings to be herein-after referred to and representing a
tramway locomotive as constructed with my improvements. In these
Drawings the same reference numerals are used to mark the same or
like parts wherever they are repeated.
Figure 1 of the Drawings is a horizontal section; and Figures 2 and 3
are longitudinal and transverse vertical sections; Figure 4 is a section
of a part of the receiver 1, showing the internal staying; and Figure 5
is a sectional diagram explanatory of the mechanism whereby the cut-off
valves are adjusted to the pressure. The lower part of the body of the
carriage is formed by an oblong rectangular receiver 1 in which the
compressed air required for a journey or stage is stored, and which has
a rectangular well or opening 2 formed at its middle to receive the lower
parts of a pair of inverted cylinder engines 3. These engines 3 are
arranged to directly drive the cranked axle 4 of a pair of driving
wheels 5, and the cylinders are provided with cut-off valves in addition
to the ordinary or equivalent slide valves, the said cut-off valves being
worked by separate eccentrics.
The valve rods 6, 7, may be acted on through link motion gear of the
common well known kind, but which is not shown in the Drawings,
and it is to be understood that various minor details not shown in the
Drawings or not referred to in this description are to be constructed as
in any existing arrangements for similar purposes that may be suitable.
Tlic cut-off valves supposed to be used in the example delineated are of
the kind having in each case two plates or equivalent parts fitted to
work over ports in 'the main valve and attached to the valve rod 7 by
right-hand and left-hand screw threads so that they are adjusted more or
less apart by turning the valve rod 7. Each valve rod 7 reciprocates
through the eye of a pinion 8, by which pinion it is made to turn by a
groove and feather, the pinion being held between a pair of plates 9.
The two pinions 8 are in gear with a spur wheel 10 which has fast on it
à pinion 11 that is in gear with a toothed rack 12, and this rack is fixed
to a rod 13 of a piston 14 working in a cylinder 15. The compressed
air from the receiver 1 is admitted to the front end of the cylinder. 15.

page_text: and it causes the piston 14 to compress air confined in a vessel 16 com-
municating with the other end of the cylinder, a quantity of water or
other liquid being interposed between the piston and the confined air.
The confined air acts as a spring, and as the pressure of the air in the
receiver 1 gradually decreases with its use the piston 14 is pushed
outwards, and through the gearing herein-before described adjusts the
cut-off valves to admit the air to the cylinders 3 during correspondingly
increasing portions of the stroke.
Instead of employing a quantity of confined air as a spring, a metallic
or other suitable spring may be connected to the piston 14, and the
manner of arranging such piston and the gearing to act on the cut-off
valves as desired may be modified in a variety of ways as will be obvious
to persons acquainted with the numerous existing arrangements of
adjustable cut-off valve mechanism.
The internal staying of the receiver 1 I prefer to effect by means of
rectangular frames 17 rivetted to the top and bottom, and ends or sides
of the receiver.
In addition to the driving wheels herein-before referred to the carriage
is supported on two other pairs of wheels 18, one pair being at each end
and cach pair being arranged on a bogic or swivelling frame 19 to
facilitate the passage of the carriage over curves.
The construction of the upper part of the carriage and the arrange-
ment of seats for passengers may be varied according to circumstances,
but what is shown in the Drawings and will be casily comprehended
therefrom is convenient, and will I expect be found generally suitable.
Having thus particularly described my said Invention and the manner
of performing the same, I have to state that I do not restrict myself to
the precise details herein described or delineated, but that what I believe
to be novel and original and claim as the Invention secured to me
by the herein-before in part recited Letters Patent is,—
1. The constructing, arranging, and combining together of the pro-
pelling apparatus of locomotive carriages for tramways or common roads,
and to be worked by compressed air in the improved manner, sub-
stantially as herein-before described.
2. The providing of the engines of locomotive carriages for tramways
or common roads and worked by compressed air with separate cut-off

page_text: valves and gear arranged to be adjusted for change of pressure of the.
air, substantially in the manner herein-before described.
In witness whereof, I, the said William Dundas Scott-Moncrieff;
have hereunto set my hand and seal, this Eighth day of
September, in the year of our Lord One thousand eight hundred 5
and seventy-four.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
W. D. SCOTT-MONCRIEFF. (L.S.)