IMPROVEMENTS IN THE CONSTRUCTION OF STEAM ENGINES
Year: 1873

page_text: LETTERS PATENT to Henry Moore, of Blackburn, in the County of
Lancaster, for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION
OF STEAM ENGINES."
Sealed the 27th December 1873, and dated the 9th July 1873.
PROVISIONAL SPECIFICATION left by the said Henry Moore at the
Office of the Commissioners of Patents, with his Petition, on the
9th July 1873.
I, HENRY MOORE, of Blackburn, in the County of Lancaster, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
THE CONSTRUCTION OF STEAM ENGINES," to be as follows:—
This Invention relates more particularly to the construction of the
slide valves and the steam and exhaust ports of steam engines, the
objects being,-
Firstly. To construct a movable and variable "lap" to the valve.
Secondly. To construct an equilibrium slide valve by removing or
reducing the pressure on the back of the slide valve.

page_text: And, thirdly. So to construct and form the valve and the steam and
exhaust ports, that the admission of the steam shall be slow and gradual,
whilst the opening to the exhaust shall be instantaneous across the whole
width of the port.
Hitherto the "lap" upon a slide valve has been formed by casting a
solid flange or lap on the edge of the valve, which necessarily moves
simultaneously with the valve in both directions.
My improvements consist in forming the "lap" of a detached flange
or bar, which is so connected to the valve by claws or otherwise that
the valve can move a certain distance before it acts upon the " lap,"
which latter rests upon the cylinder facings until either pushed by the
valve or pulled by the claws, according to which direction the valve is
moving in, so that the instant the valve opens communication with the
exhaust at one end of the cylinder it also admits steam at the other end
between the edge of the valve and the movable "lap," which, by the
time the cylinder has become fully charged, is drawn by claws over the
port, and allows the steam to work expansively during the remainder of
the stroke.
When the valve returns in the reverse direction the claws leave the
Cap," and the latter does not commence to move until the valve comes
against it and pushes it forward.
To construct an equilibrium valve I place against the back of the
valve a piston, which is partly cylindrical, and works steam tight in a
cylindrical recess formed in the cover of the valve box, and is provided
with a square flange, against which the back of the valve works. The
cylindrical part of the piston removes the greater portion of the pressure
of the steam from the back of the valve, but the square corners of the
flange outside the cylindrical part afford a sufficient area to allow the
pressure of the steam to keep the valve close against the cylinder
facings. By reducing these corners the pressure can be still further
reduced if required.
In order to cause the admission of steam to the cylinder at one end to
be gradual, whilst the simultaneous opening of the port to the exhaust
at the other end shall be instantaneous across the whole width of the
exhaust opening, I form the steam and exhaust ports in the cylinder
facings at an oblique angle, and I also form the exhaust passage or recess

page_text: in the valve at a similar angle, whilst
make the front and back facings
of the valve straight and parallel, and the consequence is that whilst
the straight facing of the valve will commence to uncover only one
corner of the port on the steam side of the piston, the oblique edge of
the exhaust passage or recess in the valve, being parallel to the ports,
will commence at once to uncover the whole width of the port on the
exhaust side of the piston to the exhaust opening. If it is found that.
the straight edge of the valve does not admit the steam to the cylinder
quick enough, it can be made to admit the steam quicker by giving a
slight angle also to the back and front facing of the valve, but this angle
must in all cases be considerably less than that given to the ports and to
the exhaust passage or recess in the valve.
It will be evident that the three parts of my Invention herein-before
described may either be used separately or in combination with each
other, the movable "lap" and the equilibrium arrangement being
equally applicable to valves of the ordinary kind.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Moore in the Great Seal Patent Office on-
the 9th January 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
MOORE, of Blackburn, in the County of Lancaster, send greeting.
WHEREAS Her most. Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Ninth day of July, in the year of
our Lord One thousand eight hundred and seventy-three, in the thirty.
seventh year of Her reign, did, for Herself, Her heirs and successors;
give and grant unto me, the said Henry Moore, Her special license
that I, the said Henry Moore, my executors, administrators, and
assigns, or such others as I, the said Henry Moore, my 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 "IMPROVEMENTS IN

page_text: THE CONSTRUCTION OF STEAM ENGINES," upon the condition (amongst others)
that I, the said Henry Moore, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said Inven-.
tion, 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.
NOW KNOW YE, that I, the said Henry Moore, 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 1
following statement and accompanying Drawings (that is to say) :-
This Invention relates more particularly to the construction of the
slide valves and the steam and exhaust ports of steam engines, the
objects being,-
Firstly. To construct a movable and variable "lap” to the valve.
Secondly. To construct an equilibrium slide valve by removing or
reducing the pressure on the back of the slide valve.
And, thirdly. So to construct and form the valve and the steam and
exhaust ports, that the admission of the steam shall be slow and gradual,
whilst the opening to the exhaust shall be instantaneous across the whole
width of the port.
Hitherto the "lap" upon a slide valve has been formed by casting a
solid flange or lap on the edge of the valve, whịch necessarily moves
simultaneously with the valve in both directions.
My improvement consists in forming the "lap" of a detached flange
or bar, which is so connected to the valve by claws or otherwise that the
valve can move a certain distance before it acts upon the "lap," which
latter rests upon the cylinder facings until either pushed by the valve
or pulled by the claws, according to which direction the valve is moving
in, so that the instant the valve opens communication with the exhaust
at one end of the cylinder it also admits steam at the other end between
the edge of the valve and the movable "lap," which, by the time the
cylinder has become fully charged, is drawn by claws over the port, and
allows the steam to work expansively during the remainder of the
stroke.

page_text: cc
When the valve returns in the reverse direction the claws leave the
lap," and the latter does not commence to move until the valve comes-
against it and pushes it forward.
1
Fig. 1 in the annexed Drawing is a section of a valve box, valve, and
cylinder ports illustrating three ways of working the movable lap; a, a,
are facings of the cylinder ports; b, b, is the slide valve made without
any fixed lap; and c, c, is the valve spindle; d, d, (at the left-hand side
of the valve) is a claw or guard screwed or otherwise fixed to the valve,
and embracing the movable lap e, e, and I may here observe that
although only one claw is here shown for the sake of avoiding unne-
cessary drawing, yet it will be obvious that when this method of working
the movable lap e, e, is adopted there will be a pair of these claws or
guards on each steam side of the valve. This same remark will also
apply to the two other arrangements here described and shown on the
other steam side of the same valve. The movable lap e on the right
hand side is attached to a small spindle f, f, working through a stuffing
box, and this spindle is worked by the valve spindle c, c, either by a
tappet g, g, which is adjustable thereon, and acts against the end of the
movable lap spindle f, f, or by means of a lever h, h. The stroke of
this lever (and consequently the amount of "cut off") may be varied
as required whilst the engine is in motion by turning the small hand
wheel i, i. This wheel has a screwed boss or nut, through which works
the screwed rod k, k, the outer end of which thus forms an adjustable
fulcrum for the lever h, h, and consequently regulates the action of the
movable lap e, e. The nut wheel i, i, may have a small toothed wheel
1, 1, attached to it, which, by being connected to the governor of the
steam engine by multiplying gearing, the latter acts upon the movable
lap so effectually as to cause any irregularity of the speed of the engine
to be arrested at once, without altering the pressure of the steam in the
valve box, which latter always takes place when the governor acts upon
the throttle valve. This wheel nut and screwed rod may be dispensed
with, and the upper ends of the levers h, h, may be connected together
by means of links represented by the dotted lines m, m, the joint at n
being attached to a rod leading to the governor, and this rod being
capable of being lengthened or shortened by means of a nut with a
right and left-handed screw, the regulating and adjusting can be operated.
without stopping the engine. If preferred, the fulcrum of the lever:

page_text: h, h, may be a fixed point, and the screwed nut and wheel i, i, be placed
upon the valve spindle c, c, as shown in the sectional view Fig. 2.
To construct an equilibrium valve I place against the back of the
valve a piston, which is partly cylindrical, and works steam tight in a
cylindrical recess formed in the cover of the valve box, and is provided
with a square flange, against which the back of the valve works. The
cylindrical part of the piston removes the greater portion of the pressure
of the steam from the back of the valve, but the square corners of the
flange outside the cylindrical part afford a sufficient area to allow the
pressure of the steam to keep the valve close against the cylinder facings.
By reducing these cornors the pressure can be still further reduced if
required. This part of my Invention is also illustrated by Figs. 1 and 2.
o, ox, is a piston, the cylindrical part of which o is provided with packing
rings, and fits steam tight in a cylindrical recess formed in the valve box
cover p, p, whilst the bottom flange o* is square (as shown in the plan
view Fig. 3) and rests on the back of the valve b, b. The cylindrical
part o being steam tight, it will be evident that no steam can pass to the
upper part of the cylindrical recess above the piston excepting when the
tap q, q, is opened for that purpose, and hence it is only the pressure of
the steam upon the four corners o*, o*, which holds the valve b, b,
against the facing, and the amount of this pressure may be reduced to a
minimum by reducing the area of these corners. r, r, is a tap for
opening a communication between the space s, s, above the piston o, and
the condenser or the exhaust passage, and t, t, is for an oil cup to
lubricate the equilibrium piston o. There is a pipe u, u, passing through
a small gland or stuffing box, and through the piston o for conveying
oil between the surfaces of the back of the valve b, b, and the flange o*,
in which there is a recess formed to receive the oil or other lubricating
matter, and v, v, is a cup for applying the steam indicator or vacuum
gauge when required. w, w, are projections on the valve box cover p, p,
which are for the purpose of steadying the square part o* of the piston
whilst the valve is being moved.
In order to cause the admission of steam to the cylinder at one end to
be gradual, whilst the simultaneous opening of the port to the exhaust
at the other end shall be instantaneous across the whole width of the
exhaust opening, I form the steam and exhaust ports 1, 1, and 2, 2, in
the cylinder facings a, a, at an oblique angle, as shown at Fig. 4; and I
}

page_text: .
also form the exhaust passage or recess 3, 3, in the valve b, b, at a
similar angle, as shown at Fig. 5, whilst I make the front and back
facings of the valve at 4, 4, straight and parallel, and the consequence
is that whilst the straight facing 4, 4, of the valve will commence to
uncover only one corner of the port 1, 1, on the steam side of the piston,
the oblique edge of the exhaust passage or recess 3, 3, in the valve being
parallel to the ports will commence at once to uncover the whole width
of the port 1, 1, on the exhaust side of the piston to the exhaust opening
2, 2. If it is found that the straight edge of the valve does not admit
the steam to the cylinder quick enough, it can be made to admit the
steam quicker by giving a slight angle also to the back and front facings
4, 4, of the valve, but this angle must in all cases be considerably less
than that given to the ports 1, 1, 2, 2, and to the exhaust passage or
recess 3, 3, in the valve a, a.
It will be evident that the three parts of my Invention herein-before
described may either be used separately or in combination with each
other, the movable "lap" and the equilibrium arrangement being equally
applicable to valves of the ordinary kind.
Figs. 6 and 7 are similar views, showing the ports at a double oblique
angle, in which case the steam will commence to enter at the central
point of the port instead of at one corner.
Having now described the nature and object of my said Invention,
together with the manner in which the same is to be or may be per-
formed or carried into practical effect, I wish it to be understood that I
claim as my Invention,-
Firstly. The construction and employment of a movable and variable
"lap" for the slide valve, substantially in the manner and for the
purposes herein-before described and illustrated by the Drawings
annexed.
Secondly. The manner herein-before described and illustrated of con-
structing and applying a piston to the back of a slide valve for the
purpose of removing or reducing to a minimum the pressure upon the
back of the same.
And, thirdly. The method herein-before described and illustrated of
constructing and forming the valve and the steam and exhaust ports
respectively, whereby the admission of the steam to the cylinder is

page_text: rendered slow and gradual, whilst the opening of the port to the exhaust
is instantaneous across the whole width of the same.
In witness whereof, I, the said Henry Moore, have hereunto set
my hand and seal, this Sixth day of January, in the year of
our Lord One thousand eight hundred and seventy-four.
Witnessed by,
GEORGE DAVIES, C.E.
Patent Agent,
Manchester.
HENRY MOORE. (L.S.)