IMPROVEMENTS IN THE STEAM ENGINE, AND IN MACHINERY FOR PROPELLING
Year: 1846

page_text: SEAWARD'S SPECIFICATION.
TO ALL TO WHOM THESE PRESENTS SHALL COME. I JOHN
SEAWARD, of the Canal Iron Works, Engineer, send greeting.
- WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twelfth day of January, in the ninth year of Her reign,did,:
for Herself, Hér heirs and successors, give and grant unto me, the said John
Seaward, my exors, admors, and assigus, Her especial licence, full power, sole
privilege and authority, that I, the said John Seaward, my exors, admors, and
assigns, or such others as I, the said John Seaward, my exors, admñňors, or
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 of "IMPROVEMENTS IN THE STEAM ENGINE,
AND IN MACHINERY FOR PROPELLING;" in which said Letters Patent is contained
a proviso that I,the said John Seaward, shall cause a particular description of
the nature of my 'said Invention, and in what manner the same is to be per-
formed, 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 same, reference being there-
unto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with tbe said proviso, I, the said
John Seaward, hereby declare that the nature of my said Invention, and in
what manner the same is to be performed, are fully described in and by the
877

page_text: present Specification thereof, reference being had to the Drawings hereunto
annexed; that is to say :-
My Invention consists, firstly, of an expanding or compensating guide
block for preserving the parallelism of cross heads, and other moving parts
of steam engines. The mode of constructing and fitting this block is
represented in Sheet No. I. of the Drawings annexed.
Figure 1 is a side view of.the block; Figure 2 is a section on the line T, V;
Figure 3, a section on the line W, X; and Figure 4, a section on the line
Y, Z, of Figure 3. A, A, are the two guide bars, such as they are commonly
formed, and placed in a vertical or horizontal position, as the case may be.
The guide block is formed of three separate pieces, a centre piece B, and two
sliding or shifting pieces C, C. The hole D in the centre of B is to receive
the end of the cross head or bar. The two sliding pieces C,C, are held firmly
to the centre piece B, partly by the screw. bolts-a,a,a, and partly by the lugs
or projections b, b, b, b, while they are being at the same time continually
pressed outwards by the action of two powerfully compressed springs d, d,
placed in cavities made for the purpose, in the ends of the centre, piece B.
When, therefore, the guide block wears away. by use, all that is necessary.
is to slacken the nuts of the screw bolts a,a,a,a, when the springs d,d, acting
upon the sliding pieces c,,c, will force them out to the proper position
required to compensate for the amount of wear which has taken place.
My Invention.consists, secondly, of a new mode of constructing the
plummer. blocks of shafts of steam engines, where the force acts in a hori-
zontal or. an inclined direction.
Figure 1 of Sheet. No. II, of the Drawings annexed is a front view of my
improved plummer block; Figure 2 is a horizontal section or plan on the line
TT, of Figure 1; Figure 3 is a vertical section taken lengthways through the
plummer block on the line W,X, of Figure 2; Figure 4 is a similar vertical
section on the line. Y.,Z, of Figure 2.. A.represents (in section), a part of the
main line of shafting of a steam engine, with collars a, a;,B is the plummer
block and carriage.. The, brasses consist of four separate pieces placed side by
side in pairs in the plummer,block; one pair of brasses C, C, are formed in
the usual way, and placed horizontally, as shewn at Figure 4, being retained
in the usual.manner by means of the cap D, and two screw bolts d,d.. The
other pair, of brasses are divided in a vertical direction, as shewn at E, E, in
Figures 1 and 3, and are retained in their places by means of a cap Gand the
two screwed bolts.g,g; but, they are also tightened sideways as required by
means of,a-key H, which.is furnished with a regulating.screw.and nut h,.by
which the bearing can be.adjusted as the,.brusses wear away. A similar key

page_text: may be placed on the opposite side of the brasses so as to tighten them with-
out altering the central position of the shaft.
My Invention consists, thirdly, for a new mode of working the slide valves
of such steam engines as are furnished with double valves.
Figure 1 of Sheet No. III of the annexed Drawings is a vertical and fore
and aft section of the cylinder of a steam engine having double side valves;
Figure 2 is an external side view of the same; and Figure 3 is a fore and aft
section of the upper and lower steam passages and slides. A, is the cylinder;
B', B", are the two inlet or steam passages; C³, C₁, the two exhausting
passages; D¹, D, are the two steam slides, which are moved by the spindles
d', d, by being connected by the links a, a, &c., to the way shaft lever f¹,f¹¹;
E', E", are the exhausting slides with the spindles e¹, e", connected with the
way shaft, in the same manner as the steam slides; F¹, F11, are two weigh
shafts, one for each of the two steam slides; and V₁, V", are two similar way
shafts, one for each of the exhausting slides, and connected therewith by the
arms or levers f¹, f", and 71, 7, as before described. Each way shaft is
furnished with a hanging lever or arm 9, 9, 9,9g, by means of which the four
way shafts are connected crossways, in pairs, by the rods G¹, G"; so that the
upper steam slide and the lower exhausting slide, and the lower steam slide
and upper exhausting slide being respectively connected together, will also
open or shut together. H is a strong sliding plate or bar (coloured grey),
which is placed in a horizontal position, and slides freely backwards and
forwards between angular or bevelled bearings or edges. Motion is given to
this sliding bar by means of a rod T attached to the back of the bar, as
indicated by the dotted lines, one end of which rod is jointed to the sliding bar
at I, and the other end to the strong bent lever K, K, which turns upon a
fixed centre k. The bent lever K has motion communicated to it by the rod
L, which is connected by its upper part with the beam or some other part of
the engine, from which it can receive the required reciprocating motion. The
rod L has an open jaw at m, like the outer end of an eccentric rod, by which
it can be shipped and unshipped from the pin n of the bent lever K. On the
one end of the two upper way shafts F and V₁ are securely fixed the two
double levers M' and M" (seen more distinctly in Figures 4 and 5); these
levers are acted upon by the tappets or wipers o¹, o, and P¹, P", which are
fixed upon the sliding plate H aforesaid. Now, when the engine is at work,
the two levers M' and M" will alternately be pressed down by the aforesaid
tappets O, P, and O", P"; for, supposing the piston to be at the top of the
cylinder, and about to make the down stroke, the sliding bar H will at the
same time move in the direction of the arrow, which bringing the tappet O'in

page_text: contact with the lever M¹, the tappet O' presses the lever down, and so gives
motion to the way shaft F¹ and V", by which the two slides'D' and 'E will
be moved so far as to close the steam passage 'B' entirely, and also partly
close the exhausting passage C¹. The effect therefore of the tappet O' pressing
down the lever M' is to cut off the flow of steam by 'the passage B' into the
cylinder, but still. to leave a communication from the bottom of the cylinder to
the condenser by the partially open passage Cas'represented by the position
of the valves. in Figure 3. Now, when the tappet O' has pressed down' the
lever M³, as aforesaid, it slides along the back or upper surface of the lever
until the small tappet Plcoming in contact with the lever M³ presses it down
a' further distance, at. the same time moving the two way shafts Fland V"
together with the: two slides D¹ and "E" also a further distance, by which
the exhausting. passage C will be completely closed, as the steam passage
B¹ was before.
Now, when the tappet Pl presses down the lever M', the toe en'd'm of the
said lever, see Figures 4 and 5, will be caught by the catch Qand held there
till again liberated; but as the toe'm' thrusts back the catch Q4, it at the same
time. moves the catch Q" by means of the rods R' and 'R", and' thereby
liberates the toe m". of the lever M", which immediately'flies up in conse-
quence of the counterpoise attached to the way shaft V', 'and consequently
the two-way shafts V' and F", being thus moved, the lower steam slide D¹¹ and
upper.exhausting slide E will be thrown open, and the engine will then be in
a state to make the return stroke, when the sliding bar'H will move in the
opposite direction, and the lever M" will in its turn be operated upon by the
two tappets O" and P", by which the way shafts V¹ and F" will'be' moved,
and the corresponding slides: E' and D" will be closed-in precisely the same
manner as is before described with respect to the opposite set of valves.
The levers M, M", will be alternately thrown up as soon as the toes are
liberated from their respective.clutches Q and Q", by the counterpoises
attached to the levers.fland of the way shafts 'F' and 'V'. The two rods
sand may have attached to them"at their lower' ends 'a' weight, spring, or
other counterpoise, the upper ends being connected with the levers fand
aforesaid. The tappets O¹and O" are adjusted to any 'required'distance by
the regulating screws.T and T, so that the steam may be cut off at any
required part of the stroke, and the two tappets Pland P" are to be adjusted
by the regulating screws and t", so that they may strike the levers'M' and M"
simultaneously as the piston arrives at the bottom or top of the stroke.
Figure 4 represents the position of the levers 'M', m', 'and"M","m", before the
tappet O' has touched the lever M; while Figure 5 shows the position of these

page_text: two levers after M¹ has been pressed down by the tappet O', but before it has
been touched by the tappet P¹.
The two springs
and
are to keep the catches firmly to their work.
The cross lever is fixed on a centre p, and regulates the action of the two
.rods R¹ and R".
"
My Invention consists, fourthly, of a mode of lessening or proventing in
marine boilers the escape of water through the steam pipe, commonly called
priming." To effect this object I employ an apparatus which I call a steam
separator, which I place in the steam chamber or steam chest of the boiler, as
represented in Sheet No. IV. of the annexed Drawings. Figure 1 is a vertical
and fore and aft section of the front part of a cominon' marine boiler; and
Figure 2 is a sectional plan of the same. A is the steam chamber or open
space immediately above the water, in which the steam collects. B is the
vessel, which I call the steam separator.
It is placed within the open space or steam chamber A, and attached to the
roof or top of the boiler. It is perforated all round at top with a number of
small holes b, b. The bottom of it is made slightly dished or 'conical, and
there projects downwards from it a pipe C,which reaches to nearly the bottom
of the boiler. Within the separator there is a circular division plate E,E,which
is fixed.close to the top or roof of the boiler, and descends to about half the
depth of the separator; and outside the separator is a similar circular division
plate G;G, which is fixed also to the top of the boiler, and descends a few
inches below the lowest row of small holes formed in the top of the 'separator.
The.steam pipe D passing in at the front of the boiler, enters into the separator,
and turns upward with a bend into the space within the division plate E, E,
where it terminates in a bell mouthed top within a short distance of the top of
the boiler. The course which the steam therefore takes is this: it passes first
up between the outer división pláte G, G; and the exterior of the separator,
then through the small holes b,bjin the top of the separator, and thence down
below the inside of the separator, and the exterior of the division plate E, E,
after which it rises within the compartments E, E, and flows over into the
steam pipe D, all as iudicáted by the arrows in Figure 1. As there will be
comparatively very little commotion or ebullition within the separator, what-
ever water is carried in with the steam will subside to the bottom of the
separator, and pass off by the pipe C; and the steam will go to the cylinder
without carrying with it so great a quantity of water as is usually the case.
The larger the separator the more effectually it will operate; but it should
in no case be less than three times the diameter of the steam pipe, the bottom
should not reach below. the level of the water in the boiler. The steam

page_text: pipe may pass out from the top of the boiler, as shewn by the dotted lines
at H.
My Invention has,fifthly,relation to screw-propelled vessels, and consists in
certain improved modes of attaching the screw to the engine shaft, whereby it
can be shipped or unshipped, or,in other words,raised or lowered at pleasure.
The first of the arrangements which I adopt for this purpose is represented
in the Sheet of Drawings, No. V. Figures 1, 2, 3, and 4, are vertical sections
of the stern or after part of a vessel; Figure 5 is a horizontal section or plan
of the same. The propeller, it will be observed, is placed a little abaft the
rudder, and the propeller shaft is inclined a little on one side the rudder post,
a small part being cut out of the after part of the rudder to allow it to swing
clear of the shaft. The outer or after part of the shaft which receives the
propeller is made of a conical shape. A is a swinging frame, which is sus-
pended from bearings a, a; Figure 6 is a transverse view of the swinging
frame; B, B, are two grooved sliding pieces (which are also seen sideways in
Figure 1) the lower ends of which are formed into bearings, upon which are
supported the two journals or gudgeons a, a, of the swinging frame, that is to
say, the propeller is suspended between the two jaws or lower ends of the
swinging frame, which are formed into journals in which the propeller turns
freely. C is a strong lever attached to the swinging frame by means of which
it can be moved forwards or backwards; if this lever is drawn forward, that
is, towards the bow of the vessel, it will cause the propeller to be unshipped
from d, the end of the propeller shaft D, as shewn in Figure 3, but if the
lever C is forced the contrary way, or towards the stern of the vessel, it will
cause the propeller P to ship on to the end d of the propeller shaft when it is
in a proper position for propelling. If it is required to disconnect and remove
the propeller, the first thing to be done is to disconnect the propeller from the
end of the shaft by drawing forward the lever C of the swinging frame, then
the propeller and swinging frame can be raised up by means of the chain E,
which passes over a pulley e, to the barrel of a crane motion F, as shown in
Figure 4. Figure 7 shows the after part of the propeller shaft drawn to a
large scale. D is the propeller shaft, with its conical end d. This piece of shaft
has an aperture through its entire length to receive the spindle S, with a
screwed end T. The fore end of this part of the propeller shaft is formed into
a bow at E, to receive the worm wheelf, by means of which the spindle is
readily turned round by a worm screw connected with the worm wheel. Now,
when the propeller is shipped into its place upon the conical end of the pro-
peller shaft, the spindle S is to be turned round, and the end T will screw itself
into the bossp of the propeller, and thereby firmly hold and secure the propeller

page_text: to the shaft; and when the propeller is to be unshipped, the spindle S will have
to be unscrewed and withdrawn. Sometimes I dispense with the swinging
frame and the grooved guide pieces before described, and I employ instead.
thereof the arrangements in Sheet No.VI. of the annexed Drawings. Figure 1
is a side view of the after part or stern of a vessel (part being in section)
furnished with a screw propeller, which it will be observed is. placed a little
beyond the after part of the rudder; Figure 2 is a view of the propeller looking.
towards the stern of the vessel; and Figure 3. is a horizontal section or plan
through the centre of the propeller.shaft. P is the propeller; D, the propeller
shaft, which is inclined a little on one side of the stern post; G, G, is a strong
frame or brace of iron or other suitable material, which is firmly secured to the
stern of the vessel, and which is formed into a journal or bearing at H,in which
the after end of the propeller shaft passes,and is supported thereby. InFigurel
the propeller is shewn attached to the propeller shaft, and in a proper state for
propelling. The propeller is secured to the end of the propeller shaft by means
of a compound conical or.wedge-shaped clutch, shewn on a large scale in
Figures 4 and 5. Figure 4 is a section of the middle part of the propeller
in a plane parallel with the axis of the blades; and Figure 5 is a section at
right angles with the former.. D, D, is the outer end of the propeller shaft,
which is formed hollow to admit the spindle S, which spindle S is for the
purpose of locking or securing the propeller to the end of the propeller shaft in
the same way as in the first arrangement.before described. H; H, is the outer
bearing formed at the after part of the frame G; G, before described. P is the
propeller. L, L, is the clutch, firmly secured to the end of the propeller shaft.
The central part.or boss of the propeller is..so formed that it will readily ship
itself over and into the clutch L, L, when lowered down in a convenient
manner for that purpose, on which the spindle S is to be thrust out and turned
round, by which means the screw end T of the spindle will be screwed into the
boss of the propeller. The propeller will by this means be firmly locked and
united with the clutch and propeller shaft, and in a fit state for propelling.
And for the purpose of shipping and unshipping the propeller in this case I
make use of the following means:-I employ two straight round bars M, M,
and pointed and screwed,as shewn in Figures 1 and 2, which slide upand down
through the two guide plates N¹ and N. The lower ends of the bars are
supported on the cross bar or yoke V, by means of collars formed on the said
bars; and the yoke Vis suspended by means of two chains a, a, which passing
over sheaves b, b, are led away to the barrel of a crane motion or crab W, by
working which the two bars M, M, are raised or lowered at pleasure. On the
tace of the propeller blades, near the boss or centre, are two screwed holes,

page_text: which receive the screwed ends of the bars M, M. When the propeller is
turned round to the proper position for disconnecting, the two bars M, M,
are then lowered down and screwed into the two holes in the propeller, after
which the spindle S is drawn back, and by turning the handles of the crane
motion or crab W, the two bars M, M, will be drawn up, and will bring with
them the propeller away from the clutch at the end of the shaft. By this
means the propeller is brought up above water close up to the counter, or
stern of the vessel, when it can be readily removed altogether if required.
To re-ship the propeller it will only be necessary to reverse the course of
operation last herein-before described.
My Invention has, sixthly and lastly, relation also to screw propellers, and
consists in a mode of removing or lessening the friction and wear which arises.
from the end thrust of the propeller on the propeller shaft. With this view I
introduce continuously a thin stratum or film of oil, water, or other lubricating
substance, between the hardened surfaces of the metallic disks or friction pieces
in the following manner, represented in Sheet No. VII. of the Drawings
annexed. Figure 1 represents a side view of the inner end of a propeller
shaft; and Figure 2 is a vertical section at right angles thereto in the direc-
tion X, Y. A represents the inner end of the range of propeller shafting,
with a bearing at a. At the end of the shaft there are two hardened metallic
diaks, one of which, B, is attached by the shank 6 to the extreme end of the
shaft A, and revolves with it. The disc C is attached or fixed to the cross bar
or beam D, which sustains the whole thrust or force of the propeller shaft,
and this beam is supported to the framing of the engine or to the timber work
of the vessel in any convenient manner. The disc C is secured to the beam D
by means of the cheeks d, d, and remains stationary with the said beam. The
two discs are hollowed out so as to leave a cavity E between them of about
half the area of the disks. Into this cavity is forced, by adequate pressure, a
continuous stream of oil, water, or other lubricating substance, which spreads
itself in a thin uniform film between that part of the two discs which would
otherwise be in constant contact, but which are prevented from touching
each other in consequence of the film of oil, water, or other substance being
interposed. G is a set of three forcing or plunger pumps, similar to those
used for hydraulic presses, which are kept in constant work by the three-
throw crank shaft H, which latter receives its motion by means of the two
wheels I and K. A casing L is placed round the two discs B and C, and
forms a circular chamber, in which is received the oil, water, or other sub-
stance, as it is forced out from between the disks, after which it is conveyed
back to the cistern or tank L' by means of the pipe M.

page_text: And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that what I claim as of my
Invention is,
First, the forming of the guide blocks of steam engines in three separate
pieces, with adjusting springs and screws, as before described.
Second, the improved compound plummer block,having two pairs of brasses,
one placed horizontally, and the other vertically, as before described.
Third, the working of steam engines having double slide valves by means of
horizontal sliding bars, with double tappets at each end, as before described.
Fourth, the adaptation to steam engine boilers of a steam separator and
appendages, for the prevention or diminution of priming, as before described.
Fifth, the two several methods of connecting and disconnecting screw
propellers with and from the working shaft of screw-propelled vessels, before
described.
And, sixth, the mode before described of obviating or lessening the friction
and wear which ordinarily arises from the end thrust of the propeller against
the propeller shaft in screw-propelled vessels.
In witness whereof, I, the said John Seaward, have hereunto set my hand
and seal, this Ninth day of July, in the year of our Lord One thousand