CERTAIN IMPROVEMENTS IN THE CONSTRUCTION OF STEAM ENGINES
Year: 1834

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, SAMUEL
SEAWARD, of the Parish of All Saints, Poplar, in the County of Middlesex,
Engineer, send greeting.
WHEREAS His most Excellent Majesty King William the Fourth, by
His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Seventeenth day of October, in the fifth year of His reign,
did, for Himself, His heirs and successors, give and grant unto me, the said
Samuel Seaward, His especial licence that I, the said Samuel Scaward,
my exors, adñiors, and assigns, or such others as I, the said Samuel Seaward,
my exors, adfiors, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term of years therein
expressed, should and lawfully might make, use, exercise, and vend, within
England, Wales, the Town of Berwick-upon-Tweed, and also in all His
Colonies and Plantations abroad, my Invention of "CERTAIN IMPROVEMENTS
IN THE CONSTRUCTION OF STEAM ENGINES;" in which said Letters Patent
there is contained a proviso obliging me, the said Samuel Seaward, 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 His Majesty's High
Court of Chancery within two calendar months next and immediately after
the date of the said recited Letters Patent, as in and by the same, refer-
ence being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Samuel Seaward, do hereby describe and ascertain the nature of my said
Invention as follows, (reference being had to the Sections or Drawings in the
margin of these presents).
My Invention and Improvements consist in arranging or combining the four

page_text: principal sliding valves of steam engines in such a manner as to produce the
following effects. First, that either the upper or lower steam slide valve, or
the upper or lower eduction slide valve, in double-acting engines, or the steam
slide valve, the equilibrium slide valve, or eduction slide valve in single
engines, may, with its face, be separately taken out of its place, and either
repaired or renewed without in any way affecting or disturbing any one of the
other principal sliding valves or faces of either of the said engines; and
secondly, that each of the said four principal side valves shall be pressed
upon its face by the simple pressure of the steam only, so that, should water at
any time accumulate within the cylinder,. it will be ejected back into the steam
pipe without in any way affecting the tightness of the sliding valves or faces of
the steam engine. Thus for a double-acting engine I cause the working
cylinder to be cast with four separate nozles, branches, or passages, as shown
in the accompanying Drawing No. 1, which is a side elevation of the said
cylinder, and is intended, according to the scale at the side of the said Drawing,
to represent the cylinder of a steam engine of one hundred horse power.
A represents the cylinder, and the Figures 1, 2, 3, and 4, represent the four
nozles, branches, or passages. The Drawing No. 2 is a front elevation of the
same cylinder, shewing two of the said nozles, branches, or passages, 1 and 2.
Upon the two nozles, branches, or passages, Nos. 1 and 2, which are for the
entrance of steam into the cylinder, I attach the steam pipe D, D, as marked
in the Drawing No. 3, which is a vertical section of the same cylinder, the
same figures and letters denoting the same parts in each of the Drawings; and
upon the nozles, branches, or passages, 3 and 4, I attach the eduction pipe
G, G, as marked also in the said section No. 3; the said steam (D, D,) and
eduction (G, G,) pipes are jointed to the cylinder by means of screws and
cements, or any other of the well-known contrivances now used for that purpose.
On each of the two nozles, branches, or passages 1 and 2, and within the steam
pipe D, D, I attach a smooth face of cast iron or other metal, having an
aperture in it large enough to enable the steam conveyed by the steam pipe
(D, D.) immediately to fill the cylinder A, the smooth part of the face
standing from the cylinder. These faces may be attached with bolts or
screws, but I prefer a method which I shall hereafter describe. These faces
of cast iron or other metal are designated in the Drawing No. 3, as B, B,
attached to No. 1, with its aperture No. 11, and C, C, attached to No. 2,
with its aperture No. 12, and their thickness will vary according to the power
of the engine in which they are to be used. Upon these faces I cause two
flat side valves or shutters S and T, of cast iron or other metal, to move
either conjointly or separately by means of stalks or spills working through a

page_text: stuffing box either above or below the slide, the said slide being with a
knuckle joint at its upper or lower end, where it is attached to the stalk or
spill, by which means it is connected with the said stalk or spill so freely as
that the valve may have free motion to move off the face. Independent of the
spill or stalk, other contrivances may be used to give direct motion to the slide
valve, but I prefer the above; but in whatever way the movement is given, it is
quite necessary that the said steam slide valve should have this freedom of
motion. These slide valves or shutters, by being moved over the aperture in
the faces, will effectually prevent the steam from entering into the cylinder, and
by moving them off the said apertures. the steam will immediately fill the
cylinder either at top or bottom, as the case may require; the steam
being conveyed from the boilers by the aforesaid steam pipe D, D, attached to
the nozles, branches, or passages of the cylinder A, and the pressure of steam
in the boiler will always keep the sliding valve close to the face upon which it
moves. For the exit of the steam from the cylinder I employ two similar,
slide valves P and Q, moving on two faces E, E, and F, F, with apertures in
them, as marked respectively No. 13 and 14, one for the top and one for the
bottom of the cylinders, (sec Drawing No. 3,) but with this difference, that
instead of the faces upon which the slides move being fixed to the nozle,
branch, or passage of the cylinder, with their smoth surfaces directed from the
cylinder, the said faces E, E, and F, F, are attached to the eduction pipe
G, G, and stand with their smooth surfaces towards the cylinder, or are
otherwise so placed that the pressure of steam within the cylinder shall press
the slide valves close to the faces upon which they move. These two slides
may also be moved conjointly or separately at pleasure to allow the steam to
escape cither from the top or bottom of the cylinder, as may be required, and
thus by alternately opening and closing the apertures 1 and 2, and in like
manner the apertures 3 and 4 on the said slide faces, by an eccentric rod, or
any of the means or contrivances commonly used, the steam will produce its
required effect upon the piston. A direct motion may be given to these slide
valves in the same way as described for the steam induction slide valves; but it
is not necessary that the eduction slide valves should have a knuckle or move-
able joint where they are attached to the slide spill or stalk, as they are not
required to move off their face during the working of the engine. It is not
absolutely necessary there should be two distinct slides and faces within the
In small double-action steam
induction pipe D, D, as above described.
engines, the two steam passages in the induction pipe may be brought so
close to each other that one steam slide will answer the purpose, the slide
working over two apertures instead of one; but still as regards the eduction

page_text: slides and faces upon which they move, they must be arranged in the manne
before described. And for single action steam engines, the steam slide valve
the equilibrium slide valve, and the eduction slide valve, must also be arranged in
the manner herein-before described, by which each valve will be pressed upor
its face by the simple pressure of the steam, and all of them may be made to act
separately or conjointly as may be deemed adviseable. My method of attaching
the slide faces to the cylinder or eduction pipes, and the mode of detaching them
is as follows: The steam pipe D, D, and the eduction pipe G, G, being securely
bolted and jointed to the 4 nozles, branches, or passages of the cylinder A,
have spaces, as marked W, X, Y, Z, left in them opposite each nozle, branch,
or passage of the cylinder, to receive the slide and slide face. The steam slide
faces being placed in the said spaces, with their backs against the nozle,
branch, or passage of the cylinder, are firmly keyed with folding keys. or
wedges (as marked 9 and 10 in the Drawing No. 4), which is an enlarged
vertical section, and are also seen at 9, 9, and 10, 10, in the Drawing No. 5,
which is an enlarged horizontal section of the said slide face and nozle,
branch, or passage; these keys press on the slide face and against the steam
pipe, which binds the face close to the cylinder, nozle, branch, or passage, a
dovetail I space being left at each side, as marked 5 and 6 in the Drawing No. 5,
and a plain caulking space at the bottom and back of the said slide face, as
marked 7 and 8 in the Drawing No. 4; it is then firmly jointed or caulked
with what is commonly known by the name of soft packing, or other substances
impervious to steam, but I prefer those having a degree of elasticity in them.
This joint will remain perfect so long as the keys remain in their places, con-
sequently, should it be necessary to remove the slide face, it can be always done
in a few minutes by driving back the wedges, the dovetail form of the slides
permitting the slide face to be easily detached from the packing upon which it
has been pressed by the aforesaid folding keys or wedges. The same descrip-
tion applies equally to the manner of fixing the eduction slide faces, excepting
that their smooth surfaces are reversed, as before stated, and are keyed with
their backs from the cylinder, and pressing against the eduction pipe G, G.
The Drawing No. 6 is a vertical section on an enlarged scale of the space
marked W in the Drawing No. 3 (as hercin-before described) in the induction
steam pipe D, D. The Drawings Nos. 4, 5, and 6, are upon a scale of
double the size of the Drawings Nos. 1, 2, and 3.
Now whereas, as regards my said Invention and Improvements, I do not
claim the invention of any of the parts, apparatus, or materials employed in my
improvements in the construction of steam engines, all such parts, apparatus,
and materials having been in use for various purposes, but I claim as my Inven-
3

page_text: tion the peculiar arrangement or combination above particularly described,
whereby I am enabled to effect the entrance of steam inte, and the exit of
steam from, the working cylinder of either high-pressure or low-pressure steam
engines, using distinct slide valves and faces for the entrance as well as for the
exit of the steam, and so arranged and combined that cach slide valve shall be
pressed against the face upon which it moves, by the simple pressure of the
steam only, and thereby permitting any water which may accumulate within
the cylinder to be driven back into the steam pipe, the steam valves being
lifted off their faces by the said water to admit of its escape. And I further
claim as my Invention the manner herein-before described of attaching and
detaching each slide valve and face to or from their places, without affecting any
one of the other principal valves and faces of the steam engine. And such my
Invention and Improvements, as above particularly described, being, to the
best of my knowledge and belief, entirely new, and never before used in that
part of His said Majesty's United Kingdom called England, His said Majesty's
Dominion of Wales, or Town of Berwick-upon-Tweed, or in any of His said
Majesty's Colonies and Plantations abroad, I do hereby declare this to be my
Specification of my said Invention and Improvements; and that I do verily
believe this, my said Specification, doth comply in all respects, fully and
without disguise, with the proviso in the said herein-before recited Letters
Patent contained. Wherefore I do hereby claim to maintain exclusive right
and privilege to my said Invention and Improvements.
In witness whereof, I, the said Samuel Seaward, have hereunto set my
hand and seal, this Fifteenth day of December, in the year of our Lord
One thousand eight hundred and thirty-four.