IMPROVEMENTS IN VALVES AND PISTONS."
Year: 1853

page_text: LETTERS PATENT to John Wright Child, of Halifax, in the
County of York, and Robert Wilson, of Low Moor Iron Works,
in the same County, Engineers, for the Invention of "IMPROVEMENTS
IN VALVES AND PISTONS."
PROVISIONAL SPECIFICATION left by the said John Wright Child
and Robert Wilson at the Office of the Commissioners of Patents,.
with their Petition, on the 12th September 1853.
We, JOHN WRIGHT CHILD, of Halifax, in the County of York, and
ROBERT WILSON, of Low Moor Iron Works, in the same County,
Engineers, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN VALVES AND PISTONS" to be as follows:-
This Invention relates, in the first place, to the construction and
arrangement of valves suitable for steam engines, and for the regula-
tion of fluid currents and in various situations, wherein the acting
pressure is wholly balanced, whilst the working efficiency and means of
adjustment are greatly improved. The valves are of the cylindrical
class, the passages through them being either from the interior or the
exterior, with the like advantages in each case. In constructing a

page_text: variable expansion valve on this principle, wherein the current shall
start from the interior to pass to the exterior or vice versâ, the moving
portion consists of an open ended cylinder or tubular piece accurately
turned to fit to a corresponding cylindrical recess as the working valve
face, and in the simplest form of the arrangement this inside cylinder
has two openings in it diametrically opposite to each other and both
of the same area, so that the pressure may be completely balanced.
These openings are plain right-angled triangular cuts, the perpendicular
in each case being parallel with the axial line of the cylinder, whilst
the base is consequently at a right angle with such axis, and the
hypotenuse forms in effect a spiral cut off edge. These openings
are made to correspond with similar but smaller openings in the outer
cylinder or valve seat, and the inner cylinder having a constant
rotatory motion, the steam is allowed to pass off' from the interior or
exterior of such cylinder through these diametrically opposed ports, as
they come into correspondence, twice during each revolution. If more
than two openings are used such openings are set at cqual distances
asunder, so as still to preserve the balance of pressure. When
the cut off of the steam is to be varied the inner cylinder is tra-
versed more or less longitudinally; the further the inner cylinder is
pushed in the shorter time are the ports allowed to be open. In
making common unalterable steam and exhaust valves the steam
ways arranged on a similar principle are plain oblong passages, or
such other forms as are suitable for steam and exhaust ports, the inner
cylinder being made either to rotate completely, or to oscillate or
partially rotate on its axis. In some cases strictly cylindrical surfaces
I may not be the best; slightly conical ones may be used instead, such
surfaces being kept in proper working contact without unnecessary
friction by placing an adjusting point or centre at the smaller end of
the inner cone. The improvement in pistons consists in placing in the
ordinary or usual recess between the bottom flange of the piston body
and the cover or joint ring four metallic rings of nearly triangular
section, each one cut through or separated at one point of the circum-
ference, the two outer ones being rings of equal section throughout, but
the two inner ones of gradually increasing sectional area from the

page_text: cuts or separations to the opposite points of the circumference; these
two inner ones form springs pressing the two outer ones, not only
horizontally or outwardly against the cylinder, but also vertically
against the top and bottom of the piston.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Wright Child and Robert Wilson in the
Great Seal Patent Office on the 11th March 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we,
JOHN WRIGHT CHILD, of Halifax, in the County of York, and ROBERT
WILSON, of Low Moor Iron Works, in the same County, Engineers,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelfth day of September, in the year
of our Lord One thousand eight hundred and fifty-three, in the seven-
teenth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said John Wright Child and Robert
Wilson, Her special licence that we, the said John Wright Child and
Robert Wilson, our executors, administrators, and assigns, or such
others as we, the said John Wright Child and Robert Wilson, our
executors, administrators, or 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, ex-
ercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IM-
PROVEMENTS IN VALVES AND PISTONS," upon the condition (amongst others)
that we, the said John Wright Child and Robert Wilson, 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 John Wright Child and Robert
Wilson, do hereby declare the nature of our 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:
Our said Invention relates, in the first place, to the construction and
arrangement of valves suitable for steam engines and for the regula-
tion of fluid currents in various situations, wherein the acting pressure
is wholly balanced, whilst the working efficiency and means of adjust-
ment are greatly improved. The valves are of the cylindrical class, the
passages through them being either from the interior or the exterior,
with the like advantages in each case. In constructing a variable
expansion valve on this principle, wherein the current shall start from
the interior to pass to the exterior, or vice versâ, the moving portion
consists of an open ended cylinder or tubular piece accurately turned
to fit to a corresponding cylindrical recess as the working valve face,
and in the simplest form of the arrangement this inside cylinder has
two openings in it diametrically opposite to each other, and both of the
same area, so that the pressure may be completely balanced. These
openings are plain right-angled triangular cuts, the perpendicular
in each case being parallel with the axial line of the cylinder, whilst
the base is consequently at a right angle with such axis, and the hypo-
thenuse forms in effect a spiral cut off edge. These openings are
made to correspond with similar but smaller openings in the outer
cylinder or valve seat, and the inner cylinder having a constant rotatory
motion, the steam is allowed to pass off from the interior of such
cylinder through the diametrically opposed ports, as they come into
correspondence, twice during each revolution. If more than two
openings are used such openings are set at equal distances asunder so
as still to preserve the balance of the pressure. When the cut off of
the steam is to be varied the inner cylinder is traversed more or less
longitudinally; the further the inner cylinder is pushed in the shorter
time are the ports allowed to be open. In making common unalterable

page_text: steam and exhaust valves the steam ways arranged on a similar
principle are plain oblong passages, or of such other forms as are suitablo
for steam and exhaust ports, the inner cylinder being made either to
rotate completely or to oscillate or partially rotate. In some cases
strictly cylindrical surfaces may not be the best; slightly conical ones
may be used instead, such surfaces being kept in proper working
contact without unnecessary friction by placing an adjusting point or
centre at the smaller end of the inner cone. The improvement in
pistons consist in placing in the ordinary or usual recess between the
bottom flange of the piston body and the cover or joint ring four
metallic rings of nearly triangular section, each one cut through or
separated at one point of the circumference, the two outer ones being
rings of equal section throughout, but the two inner ones of gradually
increasing sectional area from the cuts or separations to the opposite
points of the circumference; these two inner ones form springs pressing
the two outer ones, not only horizontally or outwardly against the
cylinder, but also vertically against the top and bottom of the piston.
And in order that our said Invention may be properly understood we
shall now proceed to describe the several Figures on the two Sheets of
Drawings hereunto attached. Figure 1, on Sheet 1, of the Drawings
is a vertical section of our improved expansion valve, taken through
the axial line of the valve and through the steam pipes. Figure 2, is a
horizontal section of the same taken through the steam pipes. Figure 8,
is an elevation of the valve; and Figure 4, is an elevation of the
cylinder or case within which the valve works. Figure 5, and 6,
are diagrams of the valve and casing as developed on a plane, shewing
the shape of the covering laps in one and the shape of the ports in the
other. Figure 7, and 8, arc respectively side and back elevations of
our rotatory or oscillating valve as applied to the stean passages of
an ordinary steam cylinder, the casing cover being represented as
removed in Figure 7. Figure 9, is a horizontal section of the valve
and casing; and Figures 10, 11, and 12, are different views of the
valve picce. Figure 1, on Sheet 2, of the Drawings is an eleva-
tion, and Figure 2, is a plan of a modified arrangement of rotatory
or oscillating valve as applied to a steam cylinder; and Figures 3,

page_text: and 4, are vertical and horizontal sections corresponding. Figures 5,
and 6, are views of the valve piece at right angles to each other; and
Figures 7, and 8, are vertical sections taken through different parts of the
valve piece. Figure 9, on the same Sheet of Drawings is an elevation of
our improved piston. Figure 10, is a vertical section of the piston;
and Figure 11, is a plan of the same with half of the cover removed
to shew the internal arrangement. Figures 12, and 18, are respectively
a plan and a vertical section of one of the inner packing rings of the
piston. The expansion valve A, Figures 1, to 6, on Sheet I. of the
Drawings, is in the form of a cylinder, having certain triangular
portions cut away, and this valve works within a cylinder or chamber B,
provided with a pair of ports C, diametrically opposite to each
other. The cylinder B is fitted into or may be cast in one piece
with the valve casing D. This casing is cast with a pipe entrance at
E, for the steam, which passes thence to a segmental space F, and then
diverges along the two passages G, to the spaces H, into which
open the ends of the cylinder B, and valve A, or the steam may
be conveyed to one end only of the cylinder and valve. The steam
thus gains access to the interior of the valve, and when the posi-
tion of the valve is such that its cut away portions coincide with
the side ports C, in the cylinder B, the steam passes through those
ports into the passages I, and thence by the pipe outlet J, to the
steam cylinder. Or, instead of this routine, the steam may be made
to enter at J, and, after passing through the various parts in the
reverse order to that described, it will pass on to the steam cylinder
at E. The ports C, of the cylinder B, are triangular in shape, and
'may have one angle truncated, as at K, or not. This triangular open-
ing is disposed with one of its sides at right angles, and the other
parallel to the axis of the cylinder, whilst the third side or hypothenuse
winds helically round the cylinder. The valve piece A, has triangular
portions L, cut out to correspond to the ports C, but larger than the
latter. The valve is formed with radial feathers a, and a boss b, by
means of which it is fixed on the spindle c, passing out through the
stuffing box d. This stuffing box being inverted is lubricated from
above. For this purpose an oil cup is screwed into the top cover at e,

page_text: where the oil enters the valve casing by a small opening. A small
wire f, hung in this opening guides the oil down a small channel g,
bored down the centre of the spindle c. This channel opens at the
side of the spindle a little above the stuffing box d, so as to convey the
oil into the cup of the latter. The valve A, acts by revolving on its
axis, being so driven as to make one revolution for each double stroke
of the engine, so that as it is represented as having two ports, the
steam will be admitted to the cylinder twice during such double
stroke. Both the valve and cylinder may, however, be made with any
number of ports, the speed of the valve been made to correspond to
the intermittent supplies of steam required. The time during which
the steam is allowed to pass through the valve at each uncovering of
the ports is determined by the longitudinal adjustment of the valve
piece A. This adjustment may be effected in any convenient manner
without interfering with the regular revolution of the valve piece, and
it may either be derived from a governor, thus constituting a self-
acting arrangement, or it may be given by hand, an external index
being provided to shew the grade of expansion at which the engine is
working. If the valve piece A, is pushed up to the top of the casing
only very small portions of its cut away parts will lie within the zone
of the ports C, so that the steam will be allowed to pass through the
valve during a very small portion only of each semi-revolution. In
other words, the steam will be cut off at a very early period of the
stroke. If, however, the valve piece A, is brought down to the posi-
tion represented in the Drawings, much larger portions of its cut away
parts will lie in the zone of the ports C, and the steam communication
will consequently be maintained through a greater part of the stroke.
The valve is so proportioned that if the valve piece A, be brought down
to its lowest position the steam will not be cut off at all during the
stroke. The adjustment of the valve piece affects only the period of
covering the ports, since the edges of the valve, which recede from the
edges of the ports on uncovering the latter, are parallel to the axis of
the valve, so that no longitudinal adjustment alters the periods at
which the ports begin to open. The valve just described may be
converted into a throttle valve or stop cock, similar in action to the

page_text: ordinary throttle valve or stop cock, by making the valve piece with
ports corresponding or not in shape to the ports in the scat, which last
may be simply oblong, or of any convenient form, and dispensing with
the longitudinal movement of the valve piece, a lever being fitted on
the valve spindle for setting it to any position, as in ordinary throttle
valves. Such valves may be made slightly conical with advantage, as
hercin-after described in reference to further modifications of our
valves. In all cases the ports must be so arranged around the cir
cumference of the valve and seat as to produce a balance of pressure,
and this object will be attained in some instances by simply forming
recesses in the valve scat diametrically opposite and equal in area to
any port acting as the mouth of a passage, the valve piece, however,
being formed with equal diametrically opposed ports, or such an arrange-
ment of ports as is equivalent thereto. It will be obvious that the dia-
metrical balance of ports and passages can be obtained in various ways
to suit particular circumstances and requirements; as, for example, by
placing two ports of certain areas opposite to one of an area equal to
the sum of such areas; and wherever the diametrical balance of the
ports is referred to herein, such various means of obtaining it are to be
understood as included in the reference. The rotatory or oscillating
steam cylinder valve mechanism, represented in Figures 8, to 12, on
the same Sheet of Drawings, consists of a valve casing A, fitted by
means of the flanges B, across the face C, of the steam cylinder. The
steam enters the casing A, by the pipe D, and immediately diverges to
cach side along the passages E, to the ends F, of an inner space
turned out cylindrically or slightly conically to receive the oscil-
lating valve piece G, turned to work steam-tight in the casing.
This valve piece is worked by means of the spindle H, passing out
through the lateral stuffing box I, and formed with a cross head J,
fitting into a socket in the end of the valve piece G. The valve
piece is pressed down towards the narrow end of the conical seat
by the helical spring K, whilst a screw L, is entered through the
opposite cover in the axial line of the valve to answer as an ad-
justable centre, against which works a steel pivot M, fixed in the nar-
row end of the valve piece, so that the valve is thereby prevented from

page_text: being pressed up too tightly in its seat. The valve piece G, which is
of very peculiar configuration, is delineated in end view in Figure 7,
in vertical cross section in Figure 10, in plan in Figure 11, in hori-
zontal longitudinal section in Figure 9, and in vertical longitudinal
section in Figure 12. As already stated, the entering steam has access
at F', to both ends of the valve G. If required, however, the steam
may be made to enter the valve at one end only. The valve is formed
with two passages N, (Figures 7, 10, and 12,) extending the entire
length of the valve, and admitting the steam to two ports or openings
O, O', in the sides of the valve. The spaces N, also communicate with
each other by the central passage P. The turned out portion of the
valve casing A, has two ports Q, R, indicated by dotted lines in
Figure 7, and communicating respectively with the steam passages
Q', R', leading to the top and bottom of the steam cylinder. The
oscillation of the valve G, brings the openings O, O', alternately into
coincidence with one of the passages Q, or R, so as to admit the steam
to the top or bottom of the cylinder, as the case may be. Between
the ports Q, and R, is the port S, communicating with the exhaust
passage S¹. A space T, is cut out of the side of the valve G, to cor-
respond to the "cup" of an ordinary slide valve, so that when the
valve is so turned, as, for instance, to admit the steam through the
upper steam opening O, into the passage Q, a communication is formed
by means of the cup T, between the lower steam passage R, and the
exhaust passage S, and on the return movement of the valve, whilst the
steam enters through the opening O', to the lower passage R, the used
steam finds its way back through the passage Q, and cup T, to the ex-
haust passage S; a space T", precisely equal to the space T, is cut away
on the opposite side of the valve, and the two spaces communicate
with each other by the passages U, in addition to this spaces V, are cut
out of the valve scat diametrically opposite, and equal in arca to the
passages Q, R, and S, so that the pressure on the valve is perfectly
balanced in every respect. The modification of our improved valve
represented in Figures 1, to 8, on Sheet 2, of the Drawings, is con-
structed to be worked either continuous rotation or by oscillation.
The valve A, may be cylindrical, but it is preferred to make it slightly

page_text: conical, as represented in the Drawings. It works steam-tight in a
seat B, accurately turned out to fit it, being pressed down towards the
narrower end by a spring C, whilst an adjustable screw D, entered
through the valve casing serves to prevent the valve from being pressed
down too tight by acting as an abutting centre for the inner end of the
valve spindle E. This spindle passes out through the stuffing box F
and has a rotatory or oscillating motion given to it, as may be con-
venient. The valve A, is partially hollow, being divided into two
compartments by a central transverse diaphragm G, which also serves
to unite it to its spindle. Each compartment of the valve is provided
with a pair of ports a, b, each port being set diametrically opposite to
the other in the same compartment, but at right angles to the ports in
the other compartment, so that a line draw parallel to the axis
through any one port will lie equally between the two ports in the
adjoining compartment. The top H, and bottom I, are respectively
open to the spaces J, and K, in the valve casing, communicating the
former with the steam pipe L, and the latter with the exhaust pipe M.
The passages N, and O, from the top and bottom of the steam cylinder
communicate with the interior of the valve seat B, by elongated ports
parallel to the axis of the valve seat, and at right angles to each other
as regards the centre of the valve; recesses P, Q, corresponding to
the ports N, O, are formed in the valve seat directly opposite to the
latter. The ports N, O, are of such length in the axial line of the
valve as to communicate with both pairs of ports a, b, in the latter as
these come round in succession, so that a communication is alternately
made with the top H, and bottom I, of the valve, and since the ports
N, and O, are at right angles with each other equally with the
ports a, and v, it follows that when one of the former is in com-
munication with the top of the valve the other is in communica-
tion with the bottom. In other words, whenever a communica-
tion is made between one end of the steam cylinder and the
steam pipe a corresponding communication is formed between the
other end of the steam cylinder and the exhaust passage, and the
rotation or oscillation of the valve A, causes the interchange of
these communications at each single stroke of the cylinder piston in

page_text: precisely the same manner as it takes place in ordinary steam cylinder
valves. The recesses P, Q, opposite to the steam ports are formed for
the purpose of balancing any lateral pressure on the valve. Thus the
steam entering at H, and through the port which happens to be
opposite to the passage N, for example, will exert its pressure on the
lower part of the valve from the outside as far as the mouth of the
passage N, extends, but precisely the same amount of pressure will be
exerted on the opposite side of the valve through the opposite port of
the valve, and through the recess Q. The two forms of valve last
described are each designed to answer singly for both ends of a steam
cylinder, but it is obvious that very slight modifications will fit them
for application in pairs to each cylinder, that is to say, each serving to
regulate the ingress and egress of steam into and out of one end only
of the steam cylinder.
It will be obvious to the practical engineer that the forms, propor-
tions, and relative positions of the ports in the valves described may
be modified in various ways to obtain effects similar to those produced
by the lead or lap of ordinary steam cylinder valves. It is also obvious
that several varieties of action may be obtained by means of differential
gearing arranged to move the valve at a quicker rate during one part
of its revolution or oscillation than another. Or the motion of the
valve may be rendered intermittent, so that the change of valvular
communication may be sudden or instantaneous, if required, as for water
meters, for example. Our improved piston represented in Figures 9,
to 13, on Sheet 2, of the Drawings, consists of the body A, cast with
a lower flange B, and provided with a cover C, the outer edge D, of
which forms the upper flange, and serves to retain the packing rings
E, F. These rings are formed to the exact diameter of the cylinder,
and compose the rubbing surfaces; they are each cut through at one
side as at G, to admit of their expansion on being worn, the rings
being so placed that their cuts are at opposite sides of the piston. The
adjacent inner edges of the rings E, F, are bevilled, and in the
annular space thus formed are placed two rings H, I, shaped externally
to correspond to the internal angular faces of the rings E, F. One of

page_text: the rings II, I, is represented detached in Figures 12, and 13. This
ring is cut through, as at J, and at K, diametrically; opposite to this
cut it is of greater sectional area than at any other part, such area
being gradually increased from the points J, to K. In constructing
these rings H, I, they are formed somewhat larger in size than is
required, and a piece is cut out of each, as at J, and they have conse-
quently to be compressed to bring them to their proper size, and the
elastic action by which they tend to regain their original more expanded
form qualify them for acting as expansive springs upon the inside of
the rings E, F, so as always to keep the latter in close contact with the
surface of the cylinder. The rings II, I, are placed on the piston with
their cut sides diametrically opposite and respectively coinciding or not
with the cut sides of the external rings E, F. The horizontal or plane
surfaces of the rings are made to fit steam-tight upon the inside
surfaces of the upper and lower flanges D, B, of the piston, a sufficient
pressure for this purpose being obtained by the wedge action of the
springs rings II, I, upon the inclined inside surfaces of the outer rings
E, F. The rings E, F, may be rendered steam-tight independently of
each other by means of tongue pieces let in at the joints or cuts, as at
I, so as to prevent the passage of the steam through the cut.
Having now described and particularly ascertained the nature of our
said Invention, and the manner in which the same is or may be used
or carried into effect, we may observe, in conclusion, that we do not
confine or restrict ourselves to the precise details or arrangements
which we have had occasion to describe or refer to, as many variations
may be made therefrom without deviating from the principles or main
features of our Invention; but what we consider to be novel and
original, and therefore claim as the Invention secured to us by the
herein-before in part recited Letters Patent, is,--
First, the general arrangement and construction of valves and pistons,
as herein-before described.
Second, the application and use of rotatory or oscillating cylindrical
or conical valves, wherein the steam or other fluid is admitted into the
interior of the valve from one or both ends, and issues therefrom by

page_text: ide passages set diametrically opposite to or at equal distances from
each other, or so as to produce an equivalent effect, or wherein the
steam or other fluid enters the valve by side passages set diametrically
opposite to or at equal distances from each other, or so as to produce
an equivalent effect, or wherein the steam or other fluid enters the
valve by two or more lateral passages set diametrically opposite to or
at equal distances from each other, or so as to produce an equivalent
effect, and issues therefrom by another set or other sets of lateral
passages similarly arranged, so that all lateral pressure on the valve
may be accurately balanced, as herein-before described.
Third, the application and use in rotatory or oscillating valves of
cylindrical or conical valve seats and valves constructed in a symme-
trical manner, and with passages or recesses and inter-communicating
chambers of equal dimensions set on each side of the axis, and
diametrically opposite to each other, or so as to produce an equivalent
offect, as herein-before described.
Fourth, the arrangement and construction of rotatory variable
expansion valve mechanism, in which the cover sides of the ports and
valves are disposed angularly with reference to the plane or line of
motion of the valve, so that an adjustment of the valve in a line at
right angles to the plane or line of motion will alter the period of the
stroke or revolution of the valve at which the cover takes place, as
hercin-before described.
Fifth, the system or mode of forming rotatory or oscillating
valves and their seats of a slightly conical section, together with the
application of a spring at one end, and an adjustable abutting centre or
stop at the other, to secure a steam-tight and at the same time easy
action of the valve, as herein-before described.
Sixth, the arrangement or construction of the seats of rotatory or
oscillating cylindrical or conical valves with recessos disposed diametri-
cally opposite, and corresponding in dimensions to such passages as
enter the seat on one side only of the valve, as herein-before described.
Seventh, the application and use of a metallic packing for pistons,
wherein compressed rings of triangular section or with inclined edges

page_text: and differential thickness act as springs to press external packing rings
outwards against the internal surface of the steam cylinder, and against
the top and bottom flanges of the piston, as herein-before described.
In witness whereof, we, the said John Wright Child and Robert
Wilson, have hereunto set our hands and seals, this Tenth day
of March, in the year of our Lord One thousand eight hundred
and fifty-four
JOHN WRIGHT CHILD. (L.S.)
ROBERT WILSON.
(L.B.)