Improvements in and relating to Steam Engines.
Year: 1893

page_text: Date of Application, 7th Dec., 1893
Complete Specification Left, 7th Sept., 1894-Accepted, 27th Oct., 1894
Improvements in and relating to Steam Engines.
I, JOHN DUNCAN GRAY THOMPSON, of 159 Queen Victoria Street, London E.C.
Ventilating and Consulting Engineer, do hereby declare the nature of my inven-
tion to be as follows:-
This invention has reference to and comprises a new or improved construction or
arrangement and combination of the parts of a steam engine specially suitable for
driving dynamo electric machines, sewing machines, lathes, propelling vessels and
machinery generally.
The engine frame would consist of a cylindrical box casing made in two main
removable parts bolted together and having the driving shaft mounted in adjustable
bearings at its ends, said bearings consisting of an outer cast metal stuffing box, an
inner brass bearing and metal packing ring and an end gland extending into metal
packing and secured by studs from stuffing box flange fitted through flange on
outer end of gland and tightened up by nuts. The shaft is formed with a central
hole and has mounted on it a lubricator at the top end from which the lubricant is
made to flow through the central hole and through àpertures to the different
bearings. Two cylinders are formed in the frame-work in the same straight line in
which work trunk pistons connected by rods to a crank on the central driving
shaft. A steam chest casing is fitted over one of these cylinders and is formed with
inlet and exhaust steam ports over which work a slide valve connected by a rod,
passing through fluid tight bearings, to an eccentric mounted on the driving shaft
of the engine. A casing or trunk leads the steam from this steam chest to a port
on the closed end of the other cylinder, and the slide valve is so set and arranged
that one of these single steam acting pistons is on its outstroke while the other is
on its instroke, so as to obtain a maximum continuous power in driving. By
unscrewing the securing bolts one part of the frame can be removed and free access
got to the cylinders, pistons, cranks and eccentric for renewal or repair.
By a modified arrangement a longitudinal passage is formed through the slide
valve, and live steam is admitted to each cylinder by separate steam ports, and the
exhaust steam is led back through the same passages when the slide valve travels
to proper position, and the exhaust passages will convey the exhaust steam to one
outlet pipe. The live steam is admitted above the slide valve, and when the port
in slide valve commences to travel over the steam passage in framework or casing,
steam is admitted to drive the pistons. In this arrangement the engine framework
may be formed in two parts or cast all in one piece, and in the latter case covers
would be secured on the ends of cylinders.
The trunk pistons would each be formed preferably in two main parts, a
U shaped end part and an inner hollow sleeve part having its inner end bearing up
arainst the inner surface of solid end of the other part, the two parts being
connected or coupled together by a transverse pin. The outer end of the inner
sleeve part would be formed with a projecting bead or flange, and spring piston
rings would be interposed and secured between this flange and the hollow end of
the U shaped part of piston.
Dated the 6th December 1893.
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.

page_text: Improvements in and relating to Steam Engines.
1, JOHN DUNCAN GRAY THOMPSON of 159 Queen Victoria Street, London E.C.
Ventilating and Consulting Engineer, do hereby declare the nature of my inven-
tion and in what manner the same is to be performed to be particularly described
and ascertained in and by the following statement in writing that is to say:-
This invention has reference to and comprises a new or improved construction or
arrangement and combination of the parts of a steam engine specially suitable for
driving dynamo electric machines, sewing machines, lathes, propelling vessels and
machinery generally.
And in order that'my said invention and the manner of performing or carrying
the same into effect or practice may be properly understood, I have hereunto
appended an explanatory sheet of drawings in which Figure 1 is a sectional
elevation of my improved construction of engine, and Figure 2 a detached sectional
view of my improved construction of piston.
Referring to these drawings:-The engine frame would consist of a cylindrical
lox casing made in two removable parts A, A bolted together and having a
driving shaft B mounted in adjustable bearings at its ends, said bearings consisting
of an outer cast metal stuffing box a, an inner brass bearing a' and metal packing
ring a and an end gland a³ extending into metal packing a" and secured by
studs as from stuffing box flange a fitted through flange on outer end of gland a
and tightened up by nuts. The shaft B is formed with a central hole band has
mounted on it a lubricator at top end from which the lubricant is made to flow
through the central hole 6 and through apertures to the different bearings. Two
cylinders C, C, are formed in the frame work in the same straight line in which
work trunk pistons c, c, connected by rods c, c², to and actuating a crank con
central driving shaft B. A steam chest casing D is fitted over one of these
cylinders C and is formed with inlet and exhaust steam ports d d' over which work
a slide valve D¹ connected by a rod D2, passing through fluid tight bearings D", to
air eccentric D³ mounted on the driving shaft B of engine. A pipe D₁, or it may
be a casing or trunk leads the steam from this steam chest D to a port d on the
closed end of the other cylinder C¹, and the slide valve D', is so set and arranged
as to supply steam to one of these single steam acting pistons c or e' on its outstroke
while the other is on its instroke so as to obtain a maximum continuous power in
driving. By unscrewing the securing bolts one part A of the frame can be
removed and free access got to the cylinders, pistons, cranks and eccentric for
renewal or repair.
By a modified arrangement a longitudinal passage is formed through the slide
valve D' and live steam is admitted to each cylinder C, C, by separate steam
ports, and the exhaust steam is led back through the same passage when the
slide valve D' travels to proper position and the exhaust passages will convey the
exhaust steam to one outlet pipe. The live steam is admitted above the slide
valve, and when the port in slide valve commences to travel over the steam
passage in frame work or casing, steam is admitted to drive the pistons. In this
arrangement the engine frame work may be formed in two parts or cast all in
one piece and in the latter case covers would be secured. on the ends of cylinders.
As shown in Figure 2 the trunk pistons would each be formed preferably in two
main parts a cylindrical solid end part E and an inuer hollow sleeve part E having
its inner end E bearing up against the inner surface of solid end E of the other
part, the two parts being connected or coupled together by a transverse pin
The outer end of the inner sleeve part would be formed with a projecting bead or
flange E³ and spring piston rings would be interposed and secured at E between
this flange E³ and the hollow end Es of the cylindrical part. E of piston.
e.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
First. The construction or arrangement and combination of the parts of a steam
engine substantially as herein described in reference to and shown in the accom-
panying drawings.
Second. In steam engines the arrangement of slide valve and casing for
supplying steam to both cylinders of engine, substantially as herein described in
reference to and shown in the accompanying drawings.
Third. In steam engines the construction of trunk piston formed in two main
parts a cylindrical solid end part and a hollow sleeve part, substantially as and for
the purposes herein described in reference to and shown in the accompanying
drawings.
Dated the 6th September 1894
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.