CERTAIN IMPROVEMENTS IN STEAM ENGINES
Year: 1847

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MATTHEW
SPROULE, of Liverpool, in the County of Lancaster, Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Tenth day of March,
One thousand eight hundred and forty-seven, in the tenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Matthew Sproule, my exors, adiñiors, and assigns, Her especial license, full
power, sole privilege and authority, that I, the said Matthew Sproule, my
exors, adiñiors, and assigns, or such others as I, the said Matthew Sproule,
my exors, adors, or assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term of years therein
expressed, should and lawfully might make, use, exercise, and vend, within
England, Wales, and the Town of Berwick-upon-Tweed, and in all Her
Majesty's Colonies and Plantations abroad, and also in the Islands of Jersey,
Guernsey, Alderney, Sark, and Man, my Invention of "CERTAIN IMPROVEMENTS
IN STEAM ENGINES;" in which said Letters Patent is contained a proviso
that I, the said Matthew Sproule, shall cause a particular description of
the nature of my said Invention, and in what manner the same is to
be performed, by an instrument in writing under my hand and seal, to be
inrolled in Her said Majesty's High Court of Chancery within six calendar
months next and immediately after the date of the said in part recited Letters
Patent, as in and by the same, reference being thereunto had, will more fully
and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Matthew Sproule, hereby declare that the nature of my said Invention,
and in what manner the same is to be performed, are fully described in

page_text: and by the present Specification thereof, reference being had to the Drawings
hereunto annexed, that is to say:-
The improvements which constitute my said Invention have relation to the
working of steam engines expansively, and consist in the employment of a
valve of a new construction, which I call the "expansive clack slide valve,"
whereby the admission of the steam into the cylinder is regulated with the
greatest nicety according to the ever-varying strain on the engine. And
the manner in which the said valve is constructed and may be applied to
expansively worked engines of different descriptions is represented in the
Drawings hereunto annexed, and in the following description thereof :-
Figures 1, 2, and 3 are views of the "expansive clack slide valve," as
applied to a locomotive engine. Figure 1 is a plan of it in section, Figure 2
a side elevation, and Figure 3 a cross section on the line y, %.
o, p, are two
ports at the end of the valve, over which are suspended two clack valves a, b,
attached to the arms of a lever which vibrates on the axis a, and which valves
cut off the steam as it flows through the ports o, p, into the cylinder of the
engine; g, h, are slides which admit steam through the ports k, l, m, n, into
the ports o, p, (o, p, forming steam-tight cells when the valve is at half or
full stroke, and the clack valves down); i, j, are rods for setting the slides g, h,
forward and back in relation to the motion of the valve and the ports k, l, m, n.
The valve being set in motion by the eccentric on the crank shaft of the
engine, and the clack valve a being down over the cell o, the instant the valve
has moved so far as to uncover the port m, from under the end of the slide h,
the steam will instantly rush into the cell o, and balance the pressure which
holds the clack valve a down, whereupon the clack 6 will be immediately
thrown down by the rush of the steam into the cylinder through the port p,
leaving the steam to act expansively to the end of the stroke. The same
effect which is thus produced by the slide h and port m is necessarily obtained
by the slide g and port 1, for the clack a being now up and the clack 6 down,
as soon as the valve returns and uncovers the port 7 from under the end a
of the slide g, steam will rush into the cell p, and balance the pressure
on the clack b, when the clack a will fall down and cut off the steam,
as before. The position of the slide g, h, when the valve is at half stroke,
would give nearly an infinite expansion to the steam by the ports m. 1, the
opening commencing on the very centre of the stroke of the engine, and s
becoming less and less as the slides are moved one (9) to the right, and the
other (h) to the left, as shewn in the plan of the valve Figure 1. As the
steam when first laid on would have a tendency to throw down both valves
(a, b,) alike, there are affixed to the slides g, h, spring carriers d, d, and to

page_text: the clack valves a, b, steel planes f, f, which operate in manner following:-
By throwing the slide g to the left and the slide to the right, the spring
carriers & are made to glide under the steel planes f, f, and as the slides
advance the ports n and k open, and admit steam below the down clack valve,
which, instantly yielding to the force of the spring carrier d, is borne up,
and both clack valves caused to assume an equal opening over the steam
passages o, p. The engine will then start with steam throughout the whole
stroke, and being now in motion the slides h and 9 are reversed, which
draws the spring carriers and planes out of gear, and leaves the clack valves
to exert their own peculiar motion. Figure 4 (a side elevation), Figure 5
(a front elevation), and Figure 6 (a plan), shew the manner in which this
valve may be adapted to a marine engine. a, b, are clack valves attached, as
before, to a lever which vibrates on the centre ; g, h, are the slides on the
back of the clacks connected by the rods i, j; t, a lever which is connected at
one end by a link s, to a fixed centre on the back of the valve, and at tho
other by a link s" to a fixed centre on the valve casing; and u, v, w, a bell
crank for setting the slides g, h. By the motion of the valve up and down, the
slides receive a relative motion of 1 to 2. The bell crank is kept in a state
of parallelism by the groove slide e on the back of the valve, and the alter-
nating or changing of the expansion is effected by the lever q being thrown
forward to the left, which sets the slide back by the bell crank u, v, w, in
relation to the ports m, n, l, k, and the motion of the valve.
plifies the mode in which the same valve may be applied to pumping steam
engines. a, b, are the two clack valves; o, p, the ports or cells; h, the slide;
t, the throttle valve; g, a balanced lever connected to t, which is acted on
by the cataract e through the rod f; e" is the engine rod; a", 6", c¹¹, a bell
crank, of which the arm 6" gives the descending motion to the valve on the
ascending of the engine, and the arm c" the ascending motion to the valve on
the descending of the engine; " is the elevating plug for the arm c"; f", the
depressing plug for the arm 6"; ", the plug for elevating the cataract e and
the slide h by their respective levers c and d; " is a balance slide on the back
of the casing to take the pressure off the valve; u, a bolt which transmits the
reacting force from the balance slide to the valve, both having like motion.
The action of the engine depends, so far as regards the number of the
strokes, upon the timing of the cataract, and as regards the measure of expan-
sion, on the elevation of the plug g" on the rod e¹. Supposing the engine to
be set on by the valve being brought into the position shewn, and the ram to
be down and the piston up, and the clack valve b to be also shut, and the clack
valve a open, then steam would rush through o into the cylinder, and as the
Figure 7 exem-

page_text: engine descended the plug 9" would press up on the clutch lever 7", and
throw up the slide h over the port n, when the steam rushing into the cell
would equilibrate with the pressure upon the clack valve 6, when instantly
the other clack a over the induction port o would fall by the rush of steam
into the cylinder, while at the same time the cataract would be elevated to the
position shewn, and the throttle valve t be shut by the balanced lever connected
to g. After the shutting of the throttle valve, the plug takes the arm c, and
gives an ascending motion to the valve, bringing the ports 21 and w free to
each other, and cutting off the ports w and v, that is to say, the condenser
from the bottom of the cylinder. The cataract will now have fallen so far as
to bring down the lever g of the throttle valve t, when the steam will equili-
brate and flow from the top of the cylinder through the port 2", and down
to the bottom of the cylinder through the port w. On the ascent of the valve,
the cell o rising above the face at q, the steam equilibrates in the cell o, and
the cell p next advancing over the condenser port v, a rush of steam against
the clack valve 6 shuts it, which throws the other clack valve a wide open.
On the ascending of the engine the plug f" takes on the arm 6", and throws
the valve down into the position with the ports 2" and w cut off, and w and v
open. As the piston reaches the top of the cylinder o is opened to the educ-
tion, and then the steam again enters through the port b, and the engine
descending throws up the slide h as before, the slide h having been drawn
down to its position in relation to the port n by the falling of the cataract.
From the exemplifications that have been thus given of the application of the
"expansive clack side valve" to locomotive, marine, and pumping steam
engines, it will be seen that it may be adapted, with more or less advantage,
to expansively worked engines of every description and denomination, and
in every locality, with such modifications and additions only as any workman
of ordinary intelligence and skill can readily supply.
And having now described my said Invention, and in what manner the same
is to be performed, I declare that what I claim is the employment in steam
engines worked expansively, of whatever description or denomination the same
may be, of the "expansive clack slide valve" before described, however the
same may be varied for sake of adaptation, as long as the general arrange-
ment and combination of the parts thereof, and the manner of operating
therewith, are substantially the same as herein-before set forth.
In witness whereof, I, the said Matthew Sproule, have hereunto set my
hand and seal, this Tenth day of September, One thousand eight
hundred and forty-seven.
MATTHEW (L.S.) SPROULE.

page_text: AND BE IT REMEMBERED, that on the Tenth day of September, in
the year of our Lord 1847, the aforesaid Matthew Sproule came before our
said Lady the Queen in Her Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Specification aforesaid was stamped according
to the tenor of the Statute made for that purpose.
Enrolled the Tenth day of September, in the year of our Lord One
thousand eight hundred and forty-seven.