IMPROVEMENTS IN LOCOMOTIVE AND TRAMWAY ENGINES
Year: 1876

page_text: LETTERS PATENT to David Greig, of the Steam Plough Works, Leeds, in the
County of York, for the Invention of " IMPROVEMENTS IN LOCOMOTIVE AND
TRAMWAY ENGINES."
Scaled the 19th December 1876, and dated the 8th July 1876.
PROVISIONAL SPECIFICATION left by the said David Greig at the Office
of the Commissioners of Patents on the 8th July 1876.
DAVID GREIG, of the Steam Plough Works, Leeds, in the County of York.
"IMPROVEMENTS IN LOCOMOTIVE AND TRAMWAY ENGINES."
This Invention has for its object improvements in locomotive and tramway
engines.
Each of the driving or cranked axles of the locomotive is provided with a
separate engine, which may be of the three cylinder rotary or ordinary type.
Each engine is on a frame entirely separate from the main frame of the locomotive,
and this frame is carried principally upon the axle itself, with only such a con-
nection with other parts as to prevent it rotating about the axle. Thus the
springs are allowed free play without in any way interfering with the engines, and
the axles may also be free to lock in passing round curves.
The main frame of the engine is made hollow of a circular or rectangular
section, and the steam is admitted into it before it passes to the chimney. A
portion of the steam is thus condensed, and the water obtained serves for the
supply of the boiler.
The engines are so arranged that if required one can be used as a high-pressure
and the other as a low-pressure engine.
20 SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said David Greig in the Great Seal Patent Office on the 8th January
1877.
DAVID GREIG, of the Steam Plough Works, Leeds, in the County of York.
"IMPROVEMENTS IN LOCOMOTIVE AND TRAMWAY ENGINES."
1.77

page_text: separate engine, which may be of the three cylinder rotary or ordinary type.
Each engine is on a frame entirely separate from the main frame of the loco-
motive, and this frame is carried principally upon the axle itself, with only such a
connection with other parts as to prevent it rotating about the axle. Thus the
springs are allowed free play without in any way interfering with the engines, and
the axles may also be free to lock in passing round curves.
The main frame of the engine is made hollow, of a circular or rectangular section,
and the steam is admitted into it before it passes to the chimney; a portion of
the steam is thus condensed, and the water obtained serves for the supply of the
boiler.
The engines are so arranged that if required one can be used as a high-pressure
and the other as a low-pressure engine.
In order that my said Invention may be most fully understood and readily
carried into effect I will proceed to describe the Drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a longitudinal section, Figures 2 and 3 are transverse sections, and
Figure 4 is a sectional plan of a tramway locomotive constructed according to my
Invention. The whole structure of the locomotive is shown in these Drawings in
some detail, but I need only refer to those parts of the structure with which my
Invention is concerned.
a and a are the two cranked axles on which the driving wheels are mounted.
Each axle has three crank throws set at angular distances of 120 degrees the one
from the other. b, b, are hollow frames or cases surrounding the axles a which
pass through stuffing boxes on their sides. c, c, are steam cylinders formed in
connection with the cases b or fixed to them. There are three cylinders in each
set, and the axes of the cylinders are parallel. d, d, are links suspending the
outer ends of the cylinders c in such manner as to prevent them rotating about the
cranked axles a. In each steam cylinder there is a piston, which by a thrust
connecting rod is connected with one of the cranks on the driving axle a. The
cylinders receive steam only at their outer ends, and the exhaust steam from the
cylinders is passed into the cases b around the axles, from whence it may be passed,
as is shewn,. into the hollow frames e of the locomotive, where it is in part
condensed. Each engine or set of steam cylinders is supplied by a rotary valve f
which regulates the passage of steam into and from the cylinders.
In the arrangement shown in the Drawings the engines are both supplied with
steam from the boiler by steam pipes marked g and respectively, but if desired
one of the engines may have cylinders of larger size, and be worked by the
exhaust steam from the other or high-pressure engine.
Having thus described the nature of my said Invention, and the manner of
performing the same, I would have it understood that I claim the construction of
tramway and other locomotives with the engines supported upon the cranked axles
and by a link serving to prevent them rotating about the axle, substantially as
described.
In witness whereof, I, the said David Greig, have hereunto set my hand and
seal, this First day of January in the year of our Lord One thousand
eight hundred and seventy-coven