IMPROVEMENTS IN THE ARRANGE MENTS OF VALVES, AND IN THEIR APPLICATION TO STEAM ENGINES."
Year: 1859

page_text: LETTERS PATENT to William Pickford Wilkins, of Ipswich, in the County
of Suffolk, Engineer, for the Invention of "IMPROVEMENTS IN THE ARRANGE
MENTS OF VALVES, AND IN THEIR APPLICATION TO STEAM ENGINES."
PROVISIONAL SPECIFICATION left by the said William Pickford Wilkins
at the Office of the Commissioners of Patents, with his Petition, on
the 22nd March 1859.
I, WILLIAM PICKFORD WILKINS, of Ipswich, in the County of Suffolk,
Engineer, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN THE ARRANGEMENTS OF VALVES, AND IN THEIR APPLICATION TO STEAM
ENGINES," to be as follows:-
My Invention relates to circular valves which have rotary motion on their
In their application to steam engines I place them on the ends of the
steam cylinder, and in order to surround the stuffing-box, I make them of an
annular form. I form the ends of the cylinder with a number of radial
openings or ports, directly through & face such cylinder ends, to recieve the
valves, which consist of annular plates having a number of radial through
openings forming the induction, and corresponding with the ports before-
mentioned. In the face of this plate, intermediate and alternate with these
through openings, are a number of recesses of similar form, also radially

page_text: disposed, which form the eduction openings, and communicate at the extreme
diameter with an annular recess in the plate, which is always in communication
with the eduction passage. The back of this annular disc valve is faced, and
another disc or plate applied which has through openings, leaving sufficient
breadth of solid metal between to cover and lap over the induction openings
through the before-mentioned plate, and by which I regulate the expansion.
The first one-I drive slowly by teeth on its periphery, gearing.with a pinion
working inside the valve box, and fixed on and driven by a shaft entering through
a stuffing-box, and communicating motion from the engine. The second disc or
plate I actuate by a shaft and toothed gearing somewhat similar, but placed
in communication with the governer, in order to regulate the expansion
according to the speed of the engine, or the expansion may be regulated by
hand by a tangent screw. When the expansion disc covers and laps over the
through steam openings in the first disc or plate, at the time such openings
coincide with the ports in the cylinder ends, the steam will be altogether cut
off, or the expansion at the extreme, any departure from which position of
the expansion plate will extend the time, that the through steam openings and
the ports will remain open for the induction. I cast or form projections on
the piston, so as to enter and fill up the ports at each end of the stroke, in
order to prevent waste of steam.
:
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Pickford Wilkins in the Great Seal Patent Office on
the 22nd September 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
PICKFORD WILKINS, of Ipswich, in the County of Suffolk, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second day of March, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-second year of Her
reign, did, for Elerself, Her heirs and successors, give and grant unto me,
the said William Pickford Wilkins, Her special licence that I, the said
William Pickford Wilkins, my executors, administrators, and assigns, or such
others as I, the said William Pickford Wilkius, 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

page_text: Kingdom of Great Britain and Ireland, the Channel Islands, and Isle of
Man, an Invention for "IMPROVEMENTS IN THE ARRANGEMENTS OF VALVES, AND IN
THEIR APPLICATION TO STEAM ENGINES," upon the condition (amongst others) that
I, the said William Pickford Wilkins, 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 Invention,
and in what manner the same was to be performed, and cause the same to be
filed in the Great Scal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Pickford Wilkins, 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 three Sheets of Drawings
hereunto annexed, and to the letters and figures marked thereon, (that
is to say):-
My Invention relates to circular valves which have rotary motion on their
axes. In their application to steam engines, I place them on the ends of the
steam cylinder; and in order to surround the stuffing-box, I make them of a
circular form. I form the ends of the cylinder with a number of radial
openings or ports, directly through and face such cylinder ends to receive the
valves, which consist of annular plates, having a number of radial through
openings forming the induction, and corresponding with the ports before-
mentioned. In the face of this plate, intermediate and alternate with theso
through openings, are a number of recesses of similar form, also radially
disposed, which form the eduction; these recesses extend radially to a greater.
extent than the induction openings, and communicate at the extreme
diameter with an annular recess in the plate, which is always in communication
with the eduction passage. The back of this annular disc valve is flush,.and
another annular disc or plato applied, which has through openings, leaving
sufficient breadth of solid metal between to cover and lap over the induction
openings through the before-mentioned plate, by which I regulate the
expansion. The first valve or plate I drive slowly by teeth on its periphery.
gearing with a pinion working inside the valve box, and fixed on and. driven
by a shaft entering through a stuffing-box, and communicating motion from
the engine. The second disc or plate I actuate by a shaft and gearing some-
what similar, but placed in communication with the governor, in order to
regulate the expansion according to the speed of the engine; or the expansion
may be regulated by hand, by a tangent screw taking into the periphery of the
expansion valve or plate. When the expansion disc covers and overlaps the

page_text: through steam openings in the first disc, at the time when such openings
coincide with the ports in the cylinder ends, the steain will be altogether cut
off, or the expansion be at the extreme. Any departure of the expansion valve
from this position will extend the time that the through steam openings and
the ports will remain open for the induction. A further improvement consists
in forming and casting projections on the piston, so as to enter and fill up the
ports at each end of the stroke, in order to prevent waste of steam by their
presence in the ports, when the engine is at the dead points.
DESCRIPTION OF DRAWINGS.
Fig. 1, Sheet A, represents a longitudinal section of part of a steam engine
cylinder constructed and fitted according to my Invention, showing also a
piston fitted thereto; it is represented as being a horizontal cylinder; the
piston rod passing out at both ends, therefore, both ends are fitted and
furnished in the same manner. D is the induction passage, and E the
eduction, both cast with the cylinder, and passing from end to end thereof;
Fis a plate, which is fixed on and closes the ends of the cylinder, & through
which the ports a are formed. This plate is represented in top plan at Fig. 2,
Sheet B, and under side plan at Fig. 8, as also in sections taken at right angles
to each other in Figs. 4 & 5; all these Figures are to a scale of half the size
of Fig. 1. The ports a are ten in number, and all radiate from the centre, as
shown, but may be of any other suitable number or arrangement. This plate
F, which is fitted to the cylinder like an ordinary cover, has, besides the
through ports a, a, a through passage D', forming a continuation of the
induction passage. The eduction is also formed in this plate, and consists of
an annular space c, c, having an annular opening d, d, in the one surface of
the plate, and on the other side of plate an opening e which coincides with the
eduction passage E, as seen in Fig. 1. G is a ring, separately represented in
plan at Fig. 6, Sheet C, and in section at Fig. 7, which with the cover H and
plate F are all bolted firmly to the flange of the cylinder. The ring G thus
raises the cover I from the plate F, and forms a chamber between the two,
in which the expansion and steam valves are placed. I is the steam valve,
which consists of an annular plate, separately represented at Figs. 8, 9, 10,
and 11, Sheet C, on a scale the same as Fig. 1. Fig. 8 represents a top plan,
while Fig. 10 represents an under side plan, being that next plate F. Figs. 9
and 11 represent sections, the one through the induction passages a' in that
plate, the other through the eduction passages c'. Fig. 12, Sheet C, represents
a cross section of the ports on the line 1, 2, Fig. 10. The passages a¹ are
simply through openings, as will be seen in Fig. 9, while the eduction passages

page_text: care recesses (Fig. 11) on the under side, which all communicate with the
annular recess d', which recess coincides with the annular opening d in F.:
This valve plate is furnished with teeth around the entire periphery which'
gear with a driving pinion K, whereby a slow continuous rotary motion is
communicated to the valve I. In order to facilitate the motion of the valve,'
I recess the neck of the stuffing box formed on plate F for the reception of
friction rollers f, mounting their beatings in rings or segments g, such rollers
surrounding the stuffing box in sufficient numbers for the purpose of presenting
a suitable bearing on which to rotate the valve plate I. This valve plate in
its rotation alternately presents the passages a' and c' to the ports a, the coin-
cidence of a' with a admitting steam to the cylinder, say, for the downstroke,'
and the coincidence of c' with a¹ permits the eduction or escape of steam from:
the cylinder for the opposite motion of the piston. It will, therefore, be seen
that the rotary motion of the valve is slow as the transition from the one
passage a to the other c' is short; supposing the steam to be admitted freely
to the back of I, the steam would have free passage to the cylinder, when the
passages a¹ and ports a coincide, and free escape when the passages c¹ and
ports a coincide, which is all that is necessary when working without expansion,
but for the purposes of working the steam expansively I apply another circular
valve plate L on valve plate I.
The expansion plate L like the valve I is fitted to move on the exterior of
the stuffing box as a centro, but its motion being slight it has no friction
rollers to bear on. This valve plato L is separately represented in under side
plan at Fig. 13, Sheet A, and in section across the centre at Fig. 14; it is
furnished with only a few teeth Q at the periphery, being sufficient for the
extent of motion it has to perform. a" are the steam passages through tho
valve L, in such position and so arranged as to be at pleasure brought over or
to coincide with the ports a, so that when the passages a¹ of valve I coincide
also with the same, a clear passage is opened through them. The wholo
number being open simultaneously, any departure of the valve L from this
position tends to diminish the passage for the steam, the passage being
gradually diminished as it is moved towards the position to bring the blank
spaces h, h, of the valve L over the ports a, by which they may be entirely
closed. In order to facilitate the admission of steam to the back of valve I,
1 cut a small dip i, i, in the face of L at the passages a", which prevents the
valve L cutting off the steam entirely.
As before mentioned, the cylinder represented is that of a horizontal engine
with the piston rod M passing through both ends, and that the valves as described
at que end are repeated at the other end. Fig. 15, Sheet C,. represents

page_text: a section of the cover H on half scale of Fig. 1; and Fig. 16 represents a
section of cover at the opposite end, while Fig. 17, Sheet A, represents a plan
of the same, and Fig. 18, a section at right angles to the section Fig. 15.
:.
The shaft P carrying the pinions K, K, one for each valve I, is driven from
one end and enters at stuffing box 1, while the other end is received in a step m,
or it may pass through another stuffing box if desirable; one of the stuffing
boxes p, through which the short shafts pass for actuating the expansion valves,
is seen in the plan, Fig. 17, Sheet A, and in section, Fig. 18; it may be
stepped in a suitable step or bearing in plato F, or it may be overhung;
toothed segments are placed on such shafts to gear with the teeth Q of the
expansion valves, whereby they are moved to open more or less the pas-
sages a¹, a¹¹, such motion being given by a lever or other appliance on the
shaft by hand, or it may be placed in connection with the governor of the
steam engine to be controlled by its action, as well understood in working steam
expansively. Instead of occasional motion being communicated to the expan-
sion valves, it may be continuous in the opposite direction to that of the valve I.
Instead of pinions to act on the teeth of the expansion valve L, tangent screws
may be used, suitably actuated by their shafts by hand, or by the action of the
governor. The plates F, rings G, & covers H, are all screwed to the flanges
of the cylinder by through bolts 1, 2, as seen in the section, Fig. 1, and as
will be readily understood, while the stuffing box glands is secured by studs t,
passing through cover H into the metal of the stufling box of plate F, as also
seen in Fig. 1. The parts being so arranged, and shaft P being connected
with the main shaft of the engine, so that the valvo I, J, will receive one
revolution for each ten strokes (ten revolutions of the engine), and in such
manner that the passages a¹, a¹ are opposite to or coincide with the ports a, a
in F when the piston is retreating from the same end of the cylinder and be
opposite the blank spaces v, v, (see Fig. 2, Sheet B, when the piston is.
advancing towards that end of the cylinder. The same arrangement is
observed at each end of the cylinder. These positions of the valves of course
succeed each other in regular succession to permit the entrance and escape of
the steam at each end of the cylinder, and produce the reciprocating motion
of the piston, as well understood. The steam enters D, as seen by the arrow,
and having free entrance under cover II, presses on the back of the valves.
Supposing the expansion valves L to be in position to coincide with tho ports a,
such valves permit the steam to have free entrance into the cylinders and
subject to the regulation of the valves I only. These valves admit the steam
when the passages a pass on and open to the ports a (the motion of valve I being
continuous) and produce the stroke, as well understood. The piston having

page_text: arrived at the opposite end of the cylinder, the passages c' will arrive opposite.
the ports a, permitting the passage passage of the steam from the cylinder
through ports a, passages c', by the annular space d'into the annular opening d
of passage c in the plate F, passing thence to the eduction passage E, as
marked by the arrows in Fig. 1. Thus far the effect may be produced without
the expansion valve L altogether. In engines required to be worked expan-
sively, I introduce expansion valves L, as described, and move such valves L
from the position before mentioned, so that they are no longer directly opposite
the ports; it may be, say, that such openings lap on each other to the
extent of one half, the steam will now be admitted only during about one half
of the stroke, and consequently expanded to a proportionate extent, for this
reason, that the passages a¹ and a, although still open, will be cut off from the
steam chest by the passages a" of valve L, no longer coinciding with a', and
therefore all further admission of the steam to the cylinder is cut off. In this
manner the passages all may be moved off or away from exact coincidenco
with the ports a, and so cause the steam to be cut off, and its admission to the
cylinder, suspended, at any earlier period of the stroke, and so expanded to a
greater extent, or it may be moved in the opposite direction, so that the
expansion shall take place in a lesser degree.
Although I have represented these valves to a horizontal cylinder, with the
piston rod emerging from each end, they may be applied equally well to a
vertical engine, having the piston emerging from the top only. At the bottom
the valves may rotate on a central stud or other bearing, and have a spring or
other means of carrying their weight and keeping them up to their faces if
necessary. It is also unnecessary that these valves should be concentric with
the cylinder, as they may be eccentric thereto, or beyond the stuffing boxes
altogether, and instead of making the induction and eduction ports in the same
valve, these separate passages may be in separate valves, placed, say, one on each
side of the centre. These valves, although described only with reference to
steam engines, are equally applicable to other purposes, for regulating the
passage of fluids.
A further improvement consists in the application of a projection or pro-
jections on the piston of steam engines, to fill up the ports at the terminations
of the strokes, by their presence in such ports. T, Fig. 1, Sheet A, is the
piston, and U, U, the projections, which, it will be observed, enter and nearly
fill up the ports a in the plate F, and so prevent such space being occupied by
steam at each alternation of the piston; such steam would otherwise bo
entirely lost, which loss has been always incurred heretofore. These pro-

page_text: jections may fit moro or less closely to the ports a, according to the accurancy
of the workmanship.
Having described the nature of my Invention, and the manner of per-
forming the same, I declare that what I claim as my Invention to be protected
by the herein-before in part recited Letters Patent is, the arrangement of
valves herein-before described, or any mere modification thereof, for the
purpose of regulating and controlling the admission and escape of steam or
other fluid to cylinders or other chambers, as herein-before described.
I also claim the projection or projections U on the pistons, as applied
thereto, as and for the purposes herein-before described.
In witness whereof, I, the said William Pickford Wilkins, have hereunto
set my hand and seal, this Twentieth day of September, in the year of
our Lord One thousand eight hundred and fifty-nine.
W. P. WILKINS.
W. P. WILKINS.