IMPROVEMENTS IN MOTIVE POWER AND PUMPING ENGINES
Year: 1880

page_text: LETTERS PATENT to Thomas Wilson, of Glasgow, in the County of Lanark,
North Britain, Engineer, and George Wilson, of Glasgow aforesaid,
Brassfounder, for an Invention of "IMPROVEMENTS IN MOTIVE POWER AND
PUMPING ENGINES."
PROVISIONAL SPECIFICATION left by the said Thomas Wilson and George
Wilson at the Office of the Commissioners of Patents on the 30th November
1880.
THOMAS WILSON, of Glasgow, in the County of Lanark, North Britain,
Engineer, and GEORGE WILSON, of Glasgow aforesaid, Brassfounder. IMPROVE
MENTS IN MOTIVE POWER AND PUMPING ENGINES."
This Invention, which relates to improvements in motive power and pumping
engines, has reference to the valves by which steam is distributed to the steam
cylinder, and it consists of an arrangement composed of a main slide or double
piston valve enclosed within a valve chamber or casing. On the spindle of the
said main valve or double piston valve, but in a separate chamber, a valve driving
piston with a suitable cushioning arrangement at each of its sides or ends is
placed. The cylinder for this piston is of the ordinary double ported construction
with a common slide or piston valve. Through the centre of the latter valve and
parallel to its line of motion is fixed or screwed a short spindle which projects into
one end of the steam cylinder. From an arm formed or fitted to the back or side
of the slide or piston valve a rod or spindle extends to the other end of the steam
cylinder, whereat it is secured in another arm from whose opposite end a second
short rod extends into the other end of the steam cylinder.
The effect of this arrangement is that when the steam piston has nearly reached
the termination of its stroke it acts upon one or other of the said short rods,
whereby the slide valve to which they are connected, as herein before set forth, is
operated upon so as to admit steam alternately to opposite ends of the chamber
containing the driving piston mounted on the same spindle with the main slide or
double piston valve, as before specified, and the said main valve is thereby caused
to distribute steam alternately to opposite ends of the steam cylinder of the motive
power or pumping engine.
Under a modification of the arrangement the auxilliary slide or piston valve
may be secured on the rod or spindle extending throughout the length of the steam
cylinder.

page_text: SPECIFICATION in pursuance of' the conditions of the Letters Patent filed by
the said Thomas Wilson and George Wilson in the Great Seal Patent Office
on the 27th May 1881.
THOMAS WILSON, of Glasgow, in the County of Lanark, North Britain,
Engineer, and GEORGE WILSON, of Glasgow aforesaid, Brassfounder. "IMPROVE-
MENTS IN MOTIVE POWER AND PUMPING ENGINES."
Our said Invention, which relates to improvements in motive power and
pumping engines, has reference to the arrangement of the valves and methods of
actuating the valves by which steam is distributed to the steam cylinders of such
engines.
And in order that our said Invention may be properly understood, we have
appended hereunto an explanatory Sheet of Drawings, and with reference to the
Figures and letters marked thereon we now proceed more particularly to set forth
several systems or modes in or under which the same is or may be used or carried
out in practice, that is to say,-
On the accompanying Drawings, Figure 1 is a longitudinal section of a steam
cylinder, the valves for admitting, distributing, and exhausting steam from which
are constructed in accordance with our said Invention; Figure 2 is an elevation of
the end of the cylinder marked A, Figure 1, with the cover B removed; and
Figure 3 is a transverse section on the line x, x, Figure 1. As shown by these Figures,
the arrangement consists of a double ported slide valve C, the inner steam spaces D
of which communicate through openings at each side of the valve with the steam
space of the valve chest or casing E, and through openings or ports F conduct the
steam into the cylinder G, through the ports H, whilst the steam is exhausted from
the cylinder through the said ports H and the ports I of the valve into the common
exhaust, all as in the ordinary method of constructing a double ported slide valve.
On the same spindle J with the double ported slide valve a valve driving piston k
is secured, the said valve driving piston being situated in a separate chamber L,
formed in the cover of the cylinder G, and provided with a cushioning
arrangement k¹ at each of its sides to deaden the blow or beat of the valve driving
piston at the termination of each stroke.
The cylinder or casing of the valve driving piston k is formed with steam and
exhaust ports of the ordinary construction, and with a port or passage b
communicating with the steam chest E, and it is provided with a common slide
valve M, as seen at Figure 1. The exhaust port c of the cylinder L communicates
with the main exhaust, as indicated in dotted lines at Figures 1 and 2. Through
the said valve M, and parallel to its line of motion, a short spindle N is secured,
one end of which projects into the steam cylinder G, as shown. The spindle N is
also connected by an arm, bracket, or strap a, seen more particularly at Figure 2,
or by two such arms placed one at each end of the valve M to a rod or spindle O,
which extends to a chamber at the other end of the steam cylinder, as seen in
dotted lines at Figure 1, whereat it is in like manner connected by another arm or
bracket P to a similar short rod or spindle Q, one end of which also projects into
the steam cylinder G.
The effect of this arrangement is that when the piston in the steam cylinder G
has nearly reached the termination of its stroke in either direction, it acts upon one
or other of the short rods or spindles N, Q, whereby through the intervention of
the rod O in one case and in the other case directly the slide valve M is operated
upon so as to admit steam alternately to opposite ends of the chamber or cylinder L
containing the valve driving piston k, whereby the said valve driving piston is
operated and with it the main double ported slide valve C, thereby distributing

page_text: steam alternately to opposite ends of the cylinder G of the motive power or pumping
engine.
Figure 4 is a side elevation, Figure 5 an elevation of the end marked R, and
Figure 6 an elevation of the end marked S (Figure 4) of a modification of the
arrangement herein before described and wherein the cylinder or chamber L of
the valve driving piston k, in lieu of being formed in a piece with one cover of
the cylinder G, as illustrated at Figure 1, is formed upon the side or barrel of the
cylinder, and constitutes a continuation of of the steam chest E; Figure 7 is a
longitudinal section of the modification, and Figures 8 and 9 are respectively
transverse sections on the lines y, y, and w, w, Figure 7.
In this arrangement the slide valve M for actuating the valve driving piston k
is formed with an eye through which the rod O passes, the valve being thereby
connected directly to the rod, as seen at Figure 8, whilst the rod is connected to
short spindles N, Q, situated in chambers at each end of the cylinder G by brackets
or arms, as hereinbefore specified.
In Figure 7 the said chambers and spindles should not appear, but are shown on
the Drawing for better understanding of the arrangement.
In lieu of employing a double ported slide valve to distribute steam to the steam
cylinder G, a double piston valve may for that purpose be mounted on the same
spindle J with the valve driving piston k, as shown in longitudinal section at T,
Figure 10. Under this arrangement the valve chest E is preferably lined with a
hollow cylindrical sleeve E¹, and in the said lining two double rows of holes or
openings 8, communicating with the ports H of the cylinder G, are made, as shown.
The holes & nearest the centre of the valve chest act as steam induction passages,
whilst the holes & nearest the ends of the chest are eduction passages, from when
the exhaust steam passes outwards into the exhaust passage through ports or
openings t or t' at the ends of the valve chest. With this arrangement the cylinder
or chamber L for the valve driving piston k and auxiliary slide valve M may also
be formed or cast on the barrel of the cylinder, as in the modification, Figures 4 to 9,
in lieu of being formed in the cylinder end or cover, as shown.
Figure 11 illustrates in longitudinal section a modification of of the preceeding
arrangement, in which the exhaust steam, on passing out from the end X of the
cylinder G through the port s is conducted through a channel u in the body of the
double piston valve C to the exhaust port at the opposite end of the cylinder G,
that is to say, the exhaust steam from both ends of the cylinder passes into the
exhaust passage through one port t.
°
Figure 12 illustrates a further modification of our said Invention, in which an
ordinary slide valve C is employed in conjunction with the auxiliary valve driving
piston k to distribute steam to the steam cylinder G in lieu of employing a double
ported slide or a double piston valve for that purpose.
With this arrangement, in order that the valve driving piston k, and with it the
main valve C, may be moved in the proper direction at the end of each stroke,
steam is admitted to and distributed from the middle of the auxiliary valve, M
instead of to and from each end as is usual, and conversely the exhaust from the
chamber L takes place at each end of the valve M, a communication being
established between the two ends by the passages through the valve M, shewn in
dotted lines, or the steam may be led from each end separately to the exhaust pipo.
The same object may be effected by crossing the ports v, w, as described in the
Specification filed in pursuance of Letters Patent granted to us, dated 18th July,
A.D. 1879, No. 2922, and shown at Figure 6 of the Drawings annexed thereto.
Having now described and particularly ascertained the nature of our said
Invention, and several systems or modes in or under which the same is or may be
used or carried out in practice, we would observe in conclusion, that what we
consider to be novel and original, and therefore claim as the Invention secured to
us by the hereinbefore in part recited Letters Patent is,-
In a motive power or pumping engine, the combination and arrangement of a
double ported main distributing slide valve, or of an ordinary slide valve, or of a

page_text: double piston valve, with a single valve driving piston (k), and with an auxiliary
slide or piston valve (M), operated (so as to distribute steam to the cylinder G) in
one direction directly through the spindle N and in the other direction through the
spindle and rod O, substantially as hereinbefore described and shown by the
several Figures on the Sheet of Drawings hereunto annexed.
In witness whereof, I, the said Thomas Wilson, on behalf of the said George
Wilson and myself, have hereunto set my hand and seal, this Twenty fifth
day of May, in the year of our Lord One thousand eight hundred and
eighty one.
Witness,
GEO. M. CRUIKSHANK,
Patent Agent,
Glasgow.
THOMAS WILSON. (L.S.)