IMPROVEMENTS IN VALVES FOR STRAM ENGINES AND OTHER PURPOSTS
Year: 1867

page_text: LETTERS PATENT to Bernard Peard Walker, of North Road House,
Wolverhampton, in the County of Stafford, Engineer, for the Invention
of "IMPROVEMENTS IN VALVES FOR STRAM ENGINES AND OTHER PURPOSTS"
Sealed the 6th September 1867, and dated the 12th March 1867.
PROVISIONAL SPECIFICATION left by the said Bernard Peard Walker
at the Office of the Commissioners of Patents, with his Petition, on the
12th March 1867.
I, BERNARD PEARD WALKER, of North Road House, Wolverhampton, in
the County of Stafford, Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN VALVES FOR STEAM ENGINES AND OTHER
PURPOSES." to be as follows:-
This Invention relates to the slide valves and corresponding valve ports or
passages of steam engines, and also to conical or disc valves for regulating the
flow of steam and other fluids under pressure, and has for its object the
partially or wholly balancing the pressure on such valves.
In constructing and arranging a slide valve and ports according to my
Invention, in place of disposing the steam and exhaust ports of the cylinder
face with their greatest length at right angles to the movement of the valve I
propose to arrange the exhaust port with its greatest length at right angles to the
steam ports and in the direction of the motion of the slide valve. The slide valve
017

page_text: in place of having an opening or recess on its under surface sufficiently large
to embrace the exhaust port, and one of the two steam ports with the space
between them, consists simply of a hollow box provided on the working face
with three openings similarly arranged to the three ports in the cylinder face,
but so disposed that the central or longitudinal exhaust port in the valve will
always work over the corresponding port in the cylinder face, whilst one or
other of the transverse ports or openings will correspond alternately with one
or other of the steam ports in the cylinder face. By this means the unbalanced
are of the slide valve due to the exhaust port may be reduced to the actual
area of the steam port alone, and this without affecting the lop or "cut off"
of the slide valve, whereas in an ordinary slide valve the unbalanced area is
equal to the area of the exhaust and steam port and the intervening space
combined. This construction of slide valve also affords facility for lengthening
the valve so as to cut off the steam close to the top and bottom of the cylinder
without increasing the unbalanced area.
In constructing an equilibrium, conical, or disc valve according to my
Invention I secure the spindle of the valve to an elastic cover or bonnet, which
may be composed of one or a series of elastic metal or other discs secured
together, or of india-rubber or other suitable elastic material, such elastic cover
or bonnet yielding sufficiently to allow of the rise and fall of the valve, and
being of sufficient area to balance the pressure on the valve. By making this
elastic cover steam and fluid tight the necessity for stuffing boxes is avoided.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Bernard Peard Walker in the Great Seal Patent Office on
the 11th September 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, BERNARD
PEARD WALKER, of North Road House, Wolverhampton, in the County of
Stafford, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of March, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Bernard Peard Walker, Her special licence that 1, the said Bernard
Peard Walker, my executors, administrators, and assigns, or such others
as I, the said Bernard Peard Walker, executors, administrators, or
assigns, should at any time agree with, and no others, from time to time

page_text: 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 VALVES FOR STEAM ENGINES AND OTHER PURPOSES."
upon the condition (amongst others) that I, the said Bernard Peard Walker, my
executors and administrators, by an instrument in writing under my hand and
seal, 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.
NOW KNOW YE, that I, the said Bernard Peard Walker, do hereby
declare the nature of my said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the accompanying Drawings, and
to the letters and figures marked thereon, that is to say:--
My said Invention relates to the slide valves and corresponding valve ports
or passages of steam engines, and also to conical or disc valves for regulating
the flow of steam and other fluids under pressure, and has for its object the
partially or wholly balancing the pressure on such valves.
In constructing and arranging a slide valve and ports according to my
Invention, in place of disposing the steam and exhaust ports of the cylinder
face with their greatest length at right angles to the movement of the valve, I
propose to arrange the exhaust port with its greatest length at right angles to
the steam ports, and in the direction of the motion of the slide valve. The
slide valve in place of having an opening or recess on its under surface
sufficiently large to embrace the exhaust port and one of the two steam ports
with the space between them consists simply of a hollow box provided on the
working face with three openings arranged similarly to the three ports in the
cylinder face, but so disposed that the central or longitudinal exhaust port in
the valve will always work over the corresponding port in the cylinder face,
whilst one or other of the transverse ports or openings will correspond alternately
with one or other of the steam ports in the cylinder face. By this means the
unbalanced area of the slide valve due to the exhaust port may be reduced to
what is due to the actual area of the steam port alone, and this without
affecting the lap or "cut off" of the slide valve, whereas in an ordinary
slide valve the unbalanced area is equal to the area of the exhaust and steam
port and the intervening space combined. This construction of slide valve
also affords facility for lengthening the valve so as to cut off the steam close
to the top and bottom of the cylinder without increasing the unbalanced area.

page_text: In constructing an equilibrium, conical, or disc valve according to my
Invention I secure the spindle of the valve to an elastic cover or bonnet,
which may be composed of one or a series of elastic metal or other discs secured
together, or of india-rubber or other suitable elastic material, such elastic
cover or bonnet yielding sufficiently to allow of the rise and fall of the valve,
and being of sufficient area to balance the pressure on the valve. By making
this elastic cover steam and fluid tight the necessity for stuffing boxes is
avoided.
And in order that my said Invention may be fully understood I shall now
proceed more particularly to describe the same, and for that purpose shall
refer to the several Figures on the annexed Sheet of Drawings, the same
letters of reference indicating corresponding parts in all the corresponding
Figures.
Figure 1 of my Drawings represents a longitudinal vertical section of a
cylinder provided with my improved construction of slide valve and ports;
Figure 2 is a plan of the valve and cylinder face; and Figure 3 is a transverse
section shewing a pair of cylinders provided with my improved slide valves,
the section being taken through the exhaust port in one cylinder and steam
port in the other cylinder.
I make the steam ports A, A, Figures 1, 2, and 3, of the ordinary
shape and proportions, whilst the exhaust port B, B, I make of the
same or nearly the same area with the steam ports and arrange it as shewn
in Figure 1, with its longer sides parallel with the axis of the cylinder, by
which arrangement the area of the exhaust is but slightly diminished by the
motion of the valve, even when the aperture in the face of the valve is made
of the same dimensions with the exhaust port of cylinder. The valve may
be cast either of iron, gun metal, or other suitable material, or, which I
prefer, may be built up of sheet metal, the back being of boiler plate iron and
the face of steel. It consists of a hollow box having rods C, C, attached to
it for connecting it with the eccentric or other gear for actuating it in the
ordinary way. Its face, or that side which is in contact with the cylinder
face when arranged for working, has three apertures which are made to
correspond with those in the cylinder face, so that the central one and one of
the end ones shall be coincident with one of the steam ports alternately and
the exhaust port, as shewn in Figure 1. In this Figure the valve is seen
with portions of the back removed, so as to exhibit the arrangement of the
steam and exhaust ports A, A, and B, the right steam port being in the
position shewn in connection with the exhaust, and the left port receiving
steam, the piston passing from left to right. In cases where the stroke of ar

page_text: engine is very short relatively to the diameter of the cylinder I use two exhaust
ports, still arranging them as before described, with the longest side parallel
with the axis of the cylinder.
The second part of my Invention, which has for its object getting rid of the
pressure which has to be overcome in opening ordinary conical puppet or
spindle valves under steam or other fluid pressure, is illustrated by Figures 4
and 5 of my Drawings. Instead of, as is usual, constructing valves of the
above-named kind with a stuffing box through which the valve spindle passes
I make use of an elastic cover or bonnet A, as shewn in Figure 4, to which
the valve B is attached by means of a spindle C. This bonnet is in one
arrangement composed of discs of steel or other suitable material connected
together by rivetting and soldering, or any suitable method, so as to permit
the spindle to rise and fall by the bending of the discs, thus allowing
the valve to rise for the admission of steam. It is evident that the
upward pressure of the steam against the bonnet will if the proportions of
area are correctly preserved balance the downward pressure upon the valve.
Motion is given to the valve by an attachment to the spindle or bonnet from
the outside, as will be readily understood. I do not limit myself to the con-
struction shewn in the Drawing, as when the lift of the valve is not required
to be great I make use of a single plate of steel or other suitable material, and
corrugate it so as to allow of its springing in a direction perpendicular to the
valve, as shewn in Figure 5.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe in conclusion that what I consider to be novel and
original, and therefore claim as the Invention secured to me by the herein-
before in part recited Letters Patent is,--
First, the method herein-before described of reducing the unbalanced
pressure on slide valves of steam or other engines by arranging the exhaust
ports with their longest sides at right angles or nearly so with the steam ports,
or in other words arranging the exhaust ports so as that their smallest sides
shall be at right angles with the path of the valve in order that the diminution
of the area of the exhaust passage by the moving of the valve shall be
a minimum, and hence the necessity for making the exhaust passage and
the opening in the face of the valve larger than one of the steam ports is
obviated.
Second, constructing spindle or puppet valves with an elastic cover or bonnet
in lieu of a rigid cover with spindle and stuffing box, which elastic bonnet or
cover having its area of proper proportions for the purpose is acted upon by the

page_text: steam or other fluid, and thereby balances the pressure upon the valve,
substantially as herein-before described.
In witness whereof, I, the said Bernard Peard Walker, have to this my
Specification set my hand and seal, the Tenth day of September,
One thousand eight hundred and sixty-seven.
BERNARD PEARD WALKER. (L.S.)