CERTAIN IMPROVEMENTS IN BALANCING OR REGULATING THE PRESSURE ON THE SLIDE VALVES OF STEAM ENGINES
Year: 1855

page_text: LETTERS PATENT to William Galloway and John Galloway, of Manchester,
in the County of Lancaster, Engineers, for the Invention of "CERTAIN
IMPROVEMENTS IN BALANCING OR REGULATING THE PRESSURE ON THE SLIDE
VALVES OF STEAM ENGINES."
Sealed the 5th June 1855, and dated the 14th March 1855.
PROVISIONAL SPECIFICATION left by the said William Galloway and
John Galloway at the Office of the Commissioners of Patents, with.
their Petition, on the 14th March 1855.
We, WILLIAM GALLOWAY and JOHN GALLOWAY, do hereby, declare the nature
of the said Invention for "CERTAIN IMPROVEMENTS IN BALANCING OR REGULATING
THE PRESSURE ON THE SLIDE VALVES OF STEAM ENGINES" to be as follows:-
The slide valves of steam engines as ordinarily constructed are enclosed in
valve boxes into which the steam for the supply of the engine is admitted
from the boiler, and in proportion to the working pressure of the steam and
the external superficies of the valve is the amount of power required to
actuate the valve upon its face.
This Invention therefore consists in the steam from the boiler being intro-
duced under or into the internal part of the valve and conveyed through
suitable ports or passages to the cylinder; the steam thus having a tendency
to throw the valve from its sliding or working face, a counter pressure of
steam is introduced into the valve box and upon the external surface of the
valve, and the external superficies of the valve exceeding its interior, it is.
evident that an admission of steam into the valve box of a reduced pressure
is sufficient to balance the valve, or neutralize the effort of the internal volume
to press the valve from its face. This counter current of steam to the valve

page_text: box is controlled by a self-acting regulating valve, as shewn in Drawing, fixed
in any
convenient situation, and is so set and adjusted as faithfully to give out
the desired amount of pressure to preponderate, in just keeping the valve
"up" by this arrangement a very serious amount of friction is taken away
and considerable power economized..For the .control of, the external steam
pressure, we do not confine ourselves to the particular construction of regu-
lating valve already referred to, but the point we more decidedly claim is,
this peculiar mode of "balancing the valve" as it is termed (without the
intervention of springs, pistons, &c.), by the use of steam, applied as already
described with the view of reducing friction and enabling "slide valves of the
langost less to be as ansily handled as the vary smallest
SPECIFICATION in pursuance of the conditions of the Letters. Patent, filed
by the said William Galloway and John Galloway, in the Great Seal
Patent Office on the 10th September 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, WILLIAM
GALLOWAY and JOHN GALLOWAY; of Manchester, in the County of Lancaster,
Engineers, send greeting..
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of March, in the year of our Lord
One thousand eight hundred and fifty-five, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us,
the said William Galloway and John Galloway, Her special license that we,
the said William Galloway and John Galloway, our exécutors, adminis-
trators, and assigns, or such others as we, the said William Galloway and
John Galloway, our 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 "CERTAIN IMPROVE
MENTS IN BALANCING OR REGULATING THE PRESSURE ON THE SLIDE VALVES OF STEAM
ENGINES," upon the condition (amongst others) that we, the said William
Galloway and John Galloway, by an instrument in writing under our hands
and seals; or under the hand and seal of one of us; 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 Seal
Patent Office within six calendar months next and 'immediately after the date
of the said Letters Patent.

page_text: NOW KNOW YE, that we, the said William Galloway and John Galloway,
do hereby declare the nature of the said Invention, and in what manner 'the
same is to be performed, to be particularly described and ascertained in and
by the following statement thereof, reference being had to the accompanying
Drawing and to the figures and letters marked thereon: (that is to say) :- :
Figure 1 of the accompanying Drawing is a longitudinal section of a
horizontal steam cylinder, with our Invention applied thereto. Figure 2 is
a plan of the same, with the slide valve and the valve box removed, so as to
show the ports or passages. The same letters refer to similar parts in both
Figures..
: .
A is the cylinder; B is the piston, and .C the piston rod; D and E are the
passages leading to the two ends of the cylinder; F and G are two passages
for the admission of the steam from the boiler; and H is the eduction passage;
I is the slide valve, which is worked by a rod Jin the ordinary manner;
K is the valve box. The valve I has a cavity or chamber a, which serves to
convey the steam from the cylinder to the eduction passage H, as in an
ordinary short slide valve. The valve. I has also another cavity or passage b
which serves, to admit the steam to the cylinder.
h
In the position in which the valve is shewn in the Drawing, both ends of
the cylinder. are open, to the eduction. passage:H; and the piston is just com-
pleting its stroke. As the valve is moved by the valve rod J in the direction
of the arrow, the passage D:becomes fully opened to the eduction, while the
passage E receives the steam, which enters the chamber 6 of the valve-from
the passage G..
In a similar manner, when the position of the valve is reversed, the steam is
admitted from the passage. F to D, while the steam escapes from the passage E
to the eduction passage. H. The steam for the supply of the engine does not,
therefore, enter the valve box and press the valve against its face, as is the
case with ordinary slide valves: The pressure of the steam has, on the con-
trary, a tendency to force the valve I away from its face, which tendency is
counteracted in the following manner
"
Liis a pipe, which conveys steam from the boiler or from the main steam
pipe through a valve M and pipe N to the valve box K... The valve M is
attached to a rod 0, which passes through a stuffing box, and is connected at
its upper end to a flexible diaphragm P, of vulcanized caoutchouc or other
suitable material, contained in a. flat. box Q. The lower part of the box Q.is
open to the atmosphere, while the upper. part communicateś by a pipe R with
the pipe N and the valve box, K. S is a lever, the short arm of which is con-
nected to the rod O, while the long arın carries a balance weight T. The

page_text: action of this apparatus is as follows:-The valve M is raised by the balance
weight, and the steam flows from the boiler into the valve box until the
pressure of the steam in the valve box acting upon the diaphragm P is
sufficient to overcome the balance weight T and close the valve M. The
entrance of the steam is thus arrested. If, however, the pressure in the valve
box diminishes, the valve M is again raised by the weight T, and steam is
thus again admitted until the pressure rises to the required amount. The
pressure in the valve box is varied or adjusted by shifting the weight T nearer
to or farther from the fulcrum of the lever. The pressure is thus regulated to
such an amount as is sufficient to keep the valve properly up to its face
without causing unnecessary friction.
U is a safety valve, to allow of the escape of steam from the valve box in the
event of its accidentally rising above the proper pressure. It will be obvious
that the form and arrangement both of the slide valve and the self-acting
regulating valve may be varied, provided the valve box be supplied with steam
at a less pressure than that which supplies the cylinder, and the slide valve be
constructed to receive the steam within it or through the face on which it
works. Thus, in Figures 3, 4, and 5, a somewhat different construction of
slide valve is shewn.
Figure 4 is a longitudinal vertical section of a portion of the vertical cylinder
of a steam engine with our Invention applied thereto. Figure 3 is a section
through the steam and exhaust pipes and the valve boxes; Figure 5 is a
horizontal section of the same.
A is the cylinder, and B is the piston; D and E are the passages leading to
the top and bottom of the cylinder; F and G are the steam passages, and
Hand Hare the exhaust passages; I and I are two slide valves working
in two boxes K and K', connected by a pipe V. The two slide valves are
connected by a rod W, and worked by a rod J, so that they move together
and open and close the passages in a similar manner to the single valve
herein-before described in reference to Figure 1. Each valve has a cavity
or chamber a for the exhaust, and another cavity or chamber for the
steam. The regulating valve is constructed as herein-before described.
The regulating valve may be opened and closed by means of a piston
working in a cylinder, in lieu of the flexible diaphragm herein-before men-
tioned, and the valve itself may be an ordinary conical valve or a double
beat valve or equilibrium valve, and other variations may be made in its
construction, provided it is arranged so as to maintain the steam in the valve
box at a lower pressure than that which enters the slide valve for the supply
of the cylinder.

page_text: Thus, in the pipe leading from the boiler or main steam pipe to the valve
box, a simple valve, loaded by a weight or spring and opening towards the
valve box, may be employed. The steam will overcome the load upon this
regulating valve and pass into the valve box, until the pressure in the valve box.
added to the load upon the regulating valve balances or equals the pressure in
the boiler. The valve will then close, but will open again whenever the differ-
ence of pressure between the boiler and valve box exceeds the load upon the
regulating valve.
Having thus described the nature of the Invention, and in what manner
the same is to be performed, we wish it to be understood that what we par-
ticularly claim is, the introduction of steam into the interior of the valve
direct from the boiler, thereby pressing the valve from its face, and that
internal pressure counteracted by introducing steam of less density into the
valve chest, exerting its reduced force upon the exterior of the valve, but of
sufficient preponderance to cause the valve to adhere to the face without that
undue friction consequent upon the ordinary slide valves.
Secondly, the peculiar mode of reducing the steam on the back of the valve
by the self-acting regulating valve or valves as herein-before described. We
wish it to be understood that we do not confine ourselves to the precise details
herein described, so long as the peculiar character of the Invention be retained,
which consists in introducing steam at working pressure from the boiler into
the interior of the valve, and enveloping the external surface with steam of less
pressure, to counteract the former with sufficient preponderance, either from
the boiler, steam exhaust pipes, or any other source, if necessary, reduced to
the required pressure by self-acting regulating valves or otherwise.
In witness whereof, we, the said William Galloway and John Galloway,
have hereunto set our hands and seals, this Eighth day of September,
in the year of our Lord One thousand eight hundred and fifty-five.
Witness,
JNO. G. MELLER,
School Mills, Manchester.
WILLIAM GALLOWAY. (L.S.)
JOHN GALLOWAY.
(L.S.)