AN IMPROVED FOUR-PORT SLIDE VALVE, AND AN IMPROVED CON- TROLLER FOR REVERSING STEAM ENGINES, AND FOR WORKING THE STEAM EXPANSIVELY IN THE CYLINDER
Year: 1843

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
SHEPHERD, of Kingston-upon-Hull, Joiner and Builder, send greeting.
WHEREAS Her present most Gracious Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Eighteenth day of November, in the seventh year o Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
William Shepherd, Her special license that I, the said William Shepherd, my
executors, administrators, and assigns, or such others as I, the said William,
Shepherd, my executors, administrators, and assigns, should at any time. agree
with, and no others, from time to time and at all times during the term of
years therein expressed, should and lawfully might make, use, exercise, and
vend, within England, Wales, and the Town of Berwick-upon-Tweed, my
Invention for "AN IMPROVED FOUR-PORT SLIDE VALVE, AND AN IMPROVED CON-
TROLLER FOR REVERSING STEAM ENGINES, AND FOR WORKING THE STEAM EXPANSIVELY
IN THE CYLINDER;" in which said Letters Patent is contained a proviso obliging
the said William Shepherd, by an instrument in writing under my hand
and seal, particularly to describe and ascertain the nature of my said Invention,
and in what manner the same is to be performed, and to cause the same to be
enrolled in Her said Majesty's High Court of Chancery within six calendar
months next and immediately after the date of the said in part recited
Letters Patent, as in and by the, reference being thereunto had, may fully
and at large appear.
me,

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
William Shepherd, do hereby declare the nature of my said Invention to con-
sist in a slide valve, having four ports-that is to say, an induction port and
an eduction port for each of the two ends of the cylinder; each pair consisting
of induction and eduction, and each pair being regulated by its own D slide on
its own portion of a double D slide valve, as herein-after described, to shut off
the steam at the extremities of the cylinder. And secondly, by attaching and
securing the working D valves upon the valve rod by a right and left handed
screw, causing the said valves to be moveable upon the rod, so that by turning
or screwing round the valve rod, the said valves can be removed further from
each other, thus cutting off the steam at an earlier period of the stroke, thereby
working the steam expansively in the cylinder. And thirdly, an improvement
for the immediate reversion of steam engines, which I call a controller, and
which consists in placing one or two cocks or circular valves in suitable positions
on or near the valve casing, which communicate both with the said valve casing
and exhaustion pipe. This controller may also be used for causing the steam
to work expansively. The operation of the whole of which said valves and
cocks will be more clearly understood by reference to the Drawings hereunto
annexed, and the figures and letters marked thereon. The similar letters
which are marked on the different Figures in each Drawing refer to the same
or parts answering a similar purpose in part of my improvements.
DESCRIPTION OF DRAWINGS.
Drawing 1, Figure 1, shews the four-port valve V, V', which alternately
opens and closes the communication between the steam ports P, P¹, and the
space A round the valve, and the passage B leading to the exhaustion pipe or
steam pipe, according as the engine is going forward or backward. The right
and left handed thread, by which the distance of the ports V and V of the four-
port valve can be increased or diminished, is shewn at T, T, on the valve rod R.
Figure 3 shews one of the means by which the engine can be reversed. S is
the steam pipe; E, the exhaustion pipe. In each of these pipes is a hollow
cock or circular valve (a, a,) with one or more steamways cut in them, which,
with its suitable gear, I call my controller; the object being to open a com-
munication between the interior of the valve and the passages leading to the
valve case. Supposing the piston to be moving in the direction shewn by the
arrow, Figure 1, the engine is moving forward. If the engine is to be reversed,
the two hollow cocks or valves a, a', are to be turned simultaneously by suitable
gear, till the opening in the valve in the steam pipe S shall open into B instead
of C, and the cocks or valve in the exhaustion pipe E shall open into C instead

page_text: of B; thus the steam from S, instead of passing along C into A, and thence
into the top of the cylinder, forcing the piston downwards, will be turned into
B, and thus pass into the bottom of the cylinder, by these means reversing the
motion of the piston, forcing it upwards instead of downwards, and conse-
quently reversing the motion of the engine. b, b, Fig. 1, shews the back of the
valve slides as they rest upon the packing. J, J, Fig. 2, is an outside view of
the manner in which the circular valves in the steam and induction pipes may
be placed in each side of the valve casing, for having their spindles in r, r, con-
nected to the suitable working part of the steam engine.
Drawing 2 shews a plan for reversing the engine by means of a controller,
as above described, and in which a common marine engine's valve is used
instead of my four-port slide valve. Fig. I is a vertical section; and Fig. 3
is an horizontal section; Fig. 2 being an outside view or elevation. V is the
D valve; S, the steam pipe; E, the exhaustion pipe, either leading of into
the atmosphere or to the condensor. In both there is a circular valve or
hollow cock (a). We will suppose the steam pipe opening into B, which
communicates into the interior middle part of the valve casing A. (The middle
part of the interior of the valve casing A is completely issolated from the top.
and bottom of the same valve casing by means of the two simi-circular
packings J, J, which press against the valve, and which are to be made of the
same shape of the valve, whatever that may be, whilst the top and bottom of
the valve casing communicate by means of the hollow space in the valve, and
the exhaustion pipe opening into C, which communicates with the top of the
valve casing; but it could be easily made to communicate with the bottom.
The steam passes then through B into A, round the valve, in at the lower
steam port P', forcing the piston up. If the engine is to be reversed, the two
hollow cocks or valves a, a', are to be turned till S opens into C, and E into B;
thus the steam will pass along C into A, and thence into the upper part of the
cylinder through P, forcing the piston downwards, thus reversing the motion
of the piston, and consequently that of the engine. In this combination the
steam could be cut off at any part of the stroke, simply by turning the valve
or cock (a, a',) in the steam pipe by means of a camb, or other suitable gearing
or machinery, so as to shut steamways C and B.
Drawing 3 exhibits an arrangement for working with my four-port slide
valve and controller; the various moving parts of the valves being formed as
pistons and piston rods of suitable materials. Fig. 1 is a vertical section;
Fig. 2 is a cross or horizontal section; and Fig. 3 is a section from a to y in
Figs. 1 and 2, showing the controller and the main valve slide. It will be
seen by the Drawing how this four-port slide and the controller move or work

page_text: lengthways; or up and down their respective cylindrical chambers. In the
Drawings 1, 2, and 3, the direction of the steam is indicated by the arrows.
In witness whereof, I, the said William Shepherd, have hereunto set my
hand and seal, this Sixteenth day of May of May, One thousand eight
hundred and forty-four.
WILLIAM SHEPHERD. (L.S.)
AND BE IT REMEMBERED, that on the Sixteenth day of May, in the
seventh 1 year of the reign of Her Majesty Queen Victoria, the said William
Shepherd came before our said Lady the Queen in Her Chancery, and
acknowledged the Instrument aforesaid, and all and every thing therein con-
tained and specified, in form above written. And also the Instrument
aforesaid was stamped according to the tenor of the Statute made in the
fifty-fifth year of the reign of His late Majesty King George the Third.
Inrolled the Eighteenth day of May, One thousand eight hundred and
förty-four.