CERTAIN IMPROVEMENTS IN STEAM ENGINES
Year: 1841

page_text: SEAWARDS SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME we, JOHN?
SEAWARD and SAMUEL SEAWARD, of the Canal Iron Works, Poplar, in the
County of Middlesex, Engineers; send greeting."
WHEREAS Her present most-Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Thirteenth day of August, in the fifth year of Her reign, did, for
Herself, Her heirs and successors, give and grant unto us, the said John'
Seaward and Samuel Seaward, Her especial licence, full power, sole privilege
and authority, that we, the said John Seaward and Samuel Seaward, our
exors, adiñors, and assigns, and such others as we, the said John Seaward
and Samuel Seaward, our exors, adñiors, 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 that part of Her Majesty's United Kingdom of
Great Britain and Ireland called England, Her Dominion of Wales, the
Town of Berwick-upon-Tweed, the Islands of Guernsey, Jersey, Alderney,
Sark, and Man, and also in all Her Majesty's Colonies and Plantations abroad,
our Invention of "CERTAIN IMPROVEMENTS IN STEAM ENGINES;" in which said
Letters Patent is contained a proviso that we, the said John Seaward and
Samuel Seaward, by an instrument in writing under our hands and seals, or
under the hands and seals of one of us; shall cause a particular description
of the nature of our said Invention, and the manner in which the same..is to
-

page_text: be performed, to be inrolled 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 same, reference being there-
unto had, will more fully and at large appear.
NOW KNOW YE, that in pursuance of the said proviso, we, the said
John Seaward and Samuel Seaward, do hereby declare that the following is
a full and true Specification of the nature of our said Improvements, and the
manner in which the same are to be performed, reference being had to the
Drawings hereunto annexed, marked Numbers 1 to 11 inclusive, and to the
letters and figures thereon, that is to say :-
Our said Improvements, which may be classed under four distinct heads or
branches, consist,―
Firstly, in various new modes of connecting and disconnecting the paddle
shafts of marine steam engines, or, in other words, the driving crank, from the
driven crank of such engines. And the first of these modes is represented in
Number 1 (Figures 1 and 2) of the Drawings hereunto annexed. L and M are
the driving and driven cranks attached to their respective shafts X and Y, the
former carrying the pin A, to which the connecting rod is affixed. B is a toe
pin which passes through the driving crank and centre of the pin A, and is
moved to and fro therein by means of a screw C, worked from the back of
the crank L. D is a recess formed in the face of the driven crank M, for the
reception of the end of the toe pin B when projected forwards by the screw C,
by which projection and fitting in of the toe pin the two cranks are connected
and made to go round together. When it is desired to disconnect the cranks,
and make them work independently of one another, all that is necessary is to s
withdraw the toe pin B by means of the screw C from the recess D of
the driven crank M. Instead of the toe pin B being passed through the
driving crank and centre of the pin A, as shewn in the preceding arrangement
(Figure 1), it may be passed through the driven crank M, as represented
in Figure 2, and received in a recess in the end of the pin A; or the whole of 3
the arrangements shewn in Figure 1 may be reversed, and the crank pin
as well as the toe pin be attached to the driven crank, and the toe pin work
into a recess on the face of the pin A, similar to that (D, D,) on the face of
the crank M. The Drawings Number 2 (Figures 1, 2, 3, 4, and 5,) repre-
sent a mode of connecting and disconnecting the cranks of marine steam s
engines different from the preceding. The end of the pin A, which is attached
to the crank L, is made of the form of the letter Y, and the broad or biforked
part fits loosely into a groove in the end of the crank M, which is made for
this purpose wider than usual. B is a bolt attached to the face of the crank

page_text: M, which is moved to and fro by means of a screw C, and which, when
projected between the forks or jaws of the pin A, connects the two cranks
securely together. When this bolt is withdrawn the cranks are disconnected,
and will revolve independently of one another. Instead of one bolt, two bolts
may be employed, as shewn in Figures 4 and 5, but in that case thè
pin A should not be of the Y form, but made square, and to fit into the space
between the two bolts B, B. The Drawing Number 3, Figure 1, shews a
mode of connecting and disconnecting a pair of engines in which the faces of
the two cranks L and M are brought close together on the intermediate
or middle shaft, which is divided into two parts, S and T, each carrying one
of cranks, and the part T having a small end V, which fits into and turns
freely in a corresponding recess of the part S. The connection and
disconnection are effected by means of a sliding or screwing toe pin A, C, in
the same way as in the other plans before described. The pair of cranks may
either be provided with one arm and pin, as represented at A, C, or with two,
one at A, C, and the other in the position indicated by the dotted lines at N, O.
The Drawing Number 4, Figures 1 and 2, represent another modification of
the general system followed in the preceding plans. The cranks L and M
are affixed to the shafts X and Y, and the former carries the crank pin A in
the usual manner; but through the end of the crank M a small toc pin B
screws to and fro, which, on being projected beyond the face of the crank,
takes into a recess in the end of the crank pin A, and thereby makes the two
cranks fast, and on being withdrawn leaves them free to revolve indepen-
dently of one another. The Drawing Number 5, Figures 1, 2, and 3, repre-
sents another method analogous to the last. The pin A, attached to the
crank L, terminates in a smaller projecting piece a, and both A and a are
solid. Through the end of the crank M, which is formed broader than usual,
two screw pins B, B, terminating in two smaller toe pieces b, b, are passed.
The projecting piece a of the pin A fits into the space between the toe pieces
b, b, of the screw pins B, B; and as these toe pieces are projected or with-
drawn by the screwing or unscrewing of the pins B, B, the cranks are connected
or disconnected.
The second branch of our said improvements consists in a certain addition
or additions to the air-pump bucket of steam engines, whereby a better vacuum
than usual can be obtained. In the working of the common air-pump, every
time the bucket is drawn up to the top of the pump there is always left
behind at the bottom of the pump a considerable quantity of water, and also
a large quantity of water in the condenser, both as represented in the Draw-
ing, Number 6, where Figure 1 shows the levels (a, a, and b, b,) of the water

page_text: in the air pump and condenser respectively, when the bucket is at the bottom
of the pump; and Figure 2 shews the corresponding, levels (a, a, and b, b,)
when it is, at the top; but until the water in the condenser is. forced or
brought as low as the bottom of the air pump, as shewn at 6, b, the uncon-
densed vapour
and gases in the condenser cannot escape; and to effect this a
corresponding column of water must be raised in the air pump (as shewn at
a, a, Figure 2), which column of water may be one, two, or three feet high,
and in proportion to its height operates as an obstruction to the escape of the
uncondensed vapour and gases. Now our improvements under this head con-
sist in more completely clearing out the water from the air pump aud condenser,
and thus enabling the uncondensed vapour and gases to escape more freely,
whereby a better vacuum in the working cylinders is produced. We employ
for this purpose a hollow vessel A,, which is fixed to the under side of the pump
bucket, as represented in the Drawing. Number 7, Figures 1 and 2. When
the bucket, with its appendage, is at the bottom of the pump, the water is at
the levels a, a, and b, b, of the air pump and condenser respectively; but as the
bucket ascends, the water flows from the condenser into the space.left unoccupied
by the hollow vessel A, and rises no further than to the levels a, a, and b,
shewn in Figure 2, leaving the uncondensed vapour and gasses free to escape
without the obstruction of the column of water ordinarily experienced, as
before explained. As the use of the hollow vessel A is simply to displace. a
portion of water equivalent to its bulk, any solid body of the same proportions
will of course serve the purpose equally well.
12.
..
The third of our said Improvements consists in certain additions to marine
steam engines, by means of which the brine or saturated or foul water may be
discharged with greater regularity and safety than at present. We employ for
this purpose three different sorts of apparatus. The first of these is represented
in the Drawing Number 8, Figures 1, 2, 3, 4, 5, and 6. Figure 1 is a
transverse vertical section, and Figure 2 a longitudinal vertical section of this
apparatus. A is a small hollow cylindrical vessel (shewn separately in Figures
5 and 6), which revolves in another vessel or case B (also shewn separately in
Figures 3 and 4). C and D are two small chambers at the top and bottom of
the outer vessel B; and a, a, is an aperture in the side of the cylindrical, vessel
A, which, as that vessel revolves, comes alternately opposite the chambers C and
D. When this aperture is opposite C, then the brine or saturated, or foul
water flows through the pipe 6 into the chamber C, and thence into and fills
the hollow cylindrical vessel A; and when by the revolution of the vessel A the
aperture comes opposite to D, the contents of the vessel A are discharged into
the chamber D, and carried off through the pipe d. In this manner, at every.
.....
t

page_text: revolution of the vessel A a quantity of brine or saturated or foul water equal
to the contents of such vessel is discharged from the boiler. The necessary
rotative action may be given to the vessel A either by a band from the shaft
of the engine running on the rigger X, X, or by any other suitable contrivance.
When the engines stop; the vessel A will cease to revolve, and no more brine-
be discharged.
9,
The second description of apparatus which we employ for the above purpose
is represented in the Drawing Number 9 (Figures 1 and 2). A is a valve box,
with its valve a, spindle b, and gland C. The spindle 6 is connected with a
compound lover d, e, which is worked by a cam affixed to the shaft which
carries a rigger h, which is put in motion by a band from the main shaft of
the engine. The brine or saturated or foul water flows into the valve box by.
the passage K, and on the rising of the valve a escapes into the discharge pipe
Lin a quantity proportional to the degree in which the valve is opened. The
compound lever d, e, has a regulating screw i, means of which the degree in
which the valve is to be opened can be previously regulated at pleasure.
The third description of apparatus which we make use to discharge brine or
saturated or foul water is represented in the Drawing Number 10. A, A, is a
valve box, with its valve a, a, and entrance and exit passages W and x; and
B, B, a second box, with its valve b, b, and entrance and exit passages Y and z.
The two valves a, a, and b, b, are connected together by a common spindle C,
which works through a stuffing box D, and the diameter of a, a, is double that
of b, b. The feed water to supply the boiler is made to pass through the valve
box A, A, as through a regulating valve, while the brine or saturated or foul.
water is discharged through the valve box B, B; the feed water whicli enters
the valve box A, A, by the passage W, raising the valve a, a, (ns also, by means
of the connecting spindle C, the valve b, b,) and flowing to the boiler through
the passage x, and the brine or saturated or foul water escaping through a pipe
leading from the bottom of the boiler into the passage Y of the valve box B, B,
and thence through the now open valve b, b, into the exit passage z. It
follows that as the diameter of the valve a, a, is double that of 6, b, there will
always be twice the quantity of feed water introduced that there is of brine or
saturated or foul water discharged; and according as these relative proportions
may be varied so also will the quantities of water admitted and discharged be
varied. When the engines are stopped, or the feed water is shut off, the valves are
pressed down on their seats and closed by a spiral spring m. E is a regulating.
spindle which passes upwards from the valve a, a, through the spiral spring m,
and screwed at the top so as to work into the nut F of the guard frame G, by the

page_text: screwing of which spindle up or down the height to which the valves a, a, and
b, b, can rise may be regulated at pleasure.
The fourth and last of our said Improvements consists of an apparatus
represented in the Drawing Number 11, by means of which the spent steam
from the working cylinders, before passing into the condenser, is made use of to
assist in producing a supply of distilled water for the service of the vessel, or
other purpose. The principle on which this apparatus is constructed is that of
distillation in vacuo, as illustrated by the well-known fact that water of only
one hundred and twenty or one hundred and thirty degrees of heat, or even
less, will rise in vapour, and may be distilled, provided a vacuum is maintained
above it. A, A, is a vessel divided into three compartments, a, Y, and D. The
central compartment Y is about three fourths filled with the sea or other water,
which may be distilled; x is an open chamber at the top of Y for the reception
(through the pipe a) of the spent steam from the working cylinders, and D a
chamber below Y, where the steam is condensed in the usual manner. The
two compartments & and D communicate with one another by means of a
number of small vertical pipes i, i, i, i, passed through the central compartment
Y; and the steam, as it descends through these pipes, imparts heat to the water
around the pipes. To produce and maintain a vacuum above the surface of
the thus moderately heated sea water, a communication is formed through the
medium of the pipe C, and refrigerator B, between the upper part of the
chamber Y and the exhausting pump E, and this pump is kept constantly
working the engine. The water in Y, under the joint influence of the heat
derived from the spent steam of the vacuum over it produced by the exhausting
pump, being raised to a state of ebullition, passes over in vapour into the refri-
gerator B, where it is condensed by means of a number of small tubes 0, 0, 0, 0,
kept constantly cold by a stream of cold water. The vapour as condensed
falls down in the state of pure distilled water into the chamber K, whence it
is drawn up by the bucket 6 of the exhausting pump E, and transferred to the
tank or reservoir T, to be made use of as required. The vessel A, A, with its
three compartments, might be altogether dispensed with by connecting the
upper part of the common condenser with the pipe C, and thereby with the
rest of the apparatus before described; but we prefer using the entire apparatus
as before described.
And having now described the nature of our said invented improvements,
and the manner in which the same are to be performed, we declare that what
we claim under our said Letters Patent is as follows:-
We claim, under the first branch, the several modes of connecting and

page_text: disconnecting the paddle shafts of marine steam engines herein-before described,
and represented in the Drawings hereunto annexed, marked Numbers 1, 2, 3,
4, and 5.
We claim, under the second branch, the addition to the ordinary air-pump
bucket of steam engines of the hollow vessel A, or of any equivalent substitute,
by means of which a like improvement in the vacuum may be effected.
We claim, under the third branch, the three several modes herein-before
described, and illustrated by the Drawings hereunto annexed, marked
Numbers 8, 9, and 10, of discharging at regular intervals, and in duly
proportioned quantities, the brine or saturated or foul water from.steam-engine
boilers.
And we claim, under the fourth branch, the apparatus herein-before
described, and represented in the Drawings hereunto annexed, marked
Number 11, for obtaining a supply of distilled water through the joint agency
of the spent steam from the working cylinders and of a vacuum artificially
produced above the water to be distilled, and whether such apparatus is used
wholly or in part.
And such our said Invention being, to the best of our knowledge and belief,
entirely new, and never before used in that part of Her Majesty's United
Kingdom of Great Britain and Ireland called England, Her Dominion of
Wales, Town of Berwick-upon-Tweed, the Islands of Guernsey, Jersey,
Alderney, Sark, and Man, and also in all Her Majesty's Colonies and Planta-
tions abroad, we do hereby declare this to be our Specification of the same, and
that we do verily believe this our said Specification doth comply in all respects,
fully and without reserve or disguise, with the proviso in the said herein-before
in part recited Letters Patent contained; wherefore we hereby claim to maintain
exclusive right and privilege to our said Invention.
In witness whereof, I, the said John Seaward, on behalf of myself and
the said Samuel Seaward, have hereunto set my hand and scal, this
Tighth day of Fabnuame One thousand night hundred and famber bo

page_text: written.
And also the Specification aforesaid was stamped according to the
tenor of the Statute made for that purpose.
Inrolled the Tenth day of February, in the year of our Lord One
thousand eight hundred and forty-two.