IMPROVEMENTS IN STEAM ENGINES AND BOILERS
Year: 1842

page_text: L
VAI
SPECIFICATION
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
LEWTHWAITE, of East Street, Manchester Square, in the County of Middlesex,
Engineer, 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 Fifteenth day of February, in the fifth year of Her reign, did, for
Herself, Her beirs and successors, give and grant unto me, the said John Lewth-
waite, Her especial licence, full power, sole privilege and authority, that I, the said
John Lewthwaite, my exors, adiñiors, and assigns, or such others as I, the said
John Lewthwaite, my exors, admors, 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 Inven-
tion of "IMPROVEMENTS IN STEAM ENGINES AND BOILERS;" in which said Letters
Patent is contained a proviso that I, the said John Lewthwaite, shall cause a
particular description of the nature of my said Invention, and in what manner
the same is to 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
thereunto bad, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
John Lewthwaite, lo hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, are fully described and

page_text: ascertained in and by the following statement thereof, reference being had to
the Drawings hereunto annexed, and to the figures and letters marked theroon,
that is to say
My Invention relates, first, to a mode of constructing and applying revolving
valves or slides to reciprocating steam engines.
And, secondly, my Invention relates to a mode of constructing steam boilers,
and in the application of a peculiarly formed auparatus for producing draft in
steam engine boiler furnaces.. And in order that my Invention may be most
fully understood, and readilly carried into effect, 1. will proceed to explain the
Drawings harounto aunovod
steam engine boiler furnaces.. And in order that my Invention may be most
fully understood, and readilly carried into effect, 1 will proceed to explain the
Drawings horonto sunexed
DESCRIPTION OF THE DRAWING.
Figure 1 represents a plan of a steam engine cylinder with my improved con-
struction of valves or slides. Figure 2 shows a vertical section of the steam cylinder
and valves or slides. Figure 3 shows a side elevation of the steam cylinder and
valves. Figure 4 shews a view of the steam cylinder, shewing the arrangement
of the steam ports and the cylindrical chamber, within which the slides work,
the cover of the chamber and the slides or valves being removed. Figure 5
shows the inner surface of the slide, having six openings for the flow of steam
into and from the parts of the steam cylinder. Figure 6 shews a side view of
the slides separately. Figure 7 shews a front or outside view of the slides
separately; and Figure 8 shews a section of the slides taken at the dotted
line a, a, at Figure 6. In each of the Figures of the Drawing the same letters
indicate similar parts. b, b, is the steam cylinder, on which is cast or applied
the side cylindrical chamber c, c; and the ports d, d, of the steam cylinder have
an even circular face, on which the slides work. It has been stated that the
slides consist of six openings, and they are formed through a circular pato e, c.
and they are so arranged that at the same time one opening will be for an induc-
tion way and another an eduction way. And it will be seen that the eduction
ways fff, are covered over and separated from the chamber c, c, so that only
the openings g, g. 9, will have communication with the chamber c, c; hence
whichever port either of the openings g may be opposed to, that port will be
open to the steam chamber c, and steam will flow into the cylinder at that port,
whilst at the same time the opposite eduction way fwill be open to the opposite
port of the steam cylinder, and the steam from that end of the steam cylinder
will flow off through the eduction way fand the openings h, h, into the educ-
tion pipe i, to the condenser or to the atmosphere, according as the steam engino
is a condensing or high pressure steam engine. is the steam pipe from tho
steam boiler. is the cover to the steam chamber e, there being a stuffing box

page_text: for the axis of the revolving valve. And in order to work this valve, the axis /
is to be so geared to the main shaft as to receive a constant rotatory motion at a
speed to make a third of a revolution for each revolution of the crank shaft,
and the gearing is to be conveniently arranged for reversing the action of the
piston when desired, by turning the slide one-sixth back.
I will now describe the second part of my Invention. Figure 9 shews a front
view of a boiler constructed according to my Invention. Figure 10 shews a
back view of the boiler. Figure 11 shews a side elevation of the boiler.
Figuro 12 shows a plan in section of the boiler, taken just above the fire bars.
Figure 18 shews a plan of the boiler in section, taken just above the tops of the
various chambers or water spaces, of which the boiler is for the most part com-
posed. Figure 14 shews an elevation of the boiler in section, taken from front
to back. Figure 15 shews another elevation of the boiler in section, taken
from side to side. Figure 16 shews parts in detail of the mode of combining
the various water spaces together, in such manner as to open steam and water
ways from one to the other. These parts are shewn on a larger scale, in order
that their construction may be more clearly scen. And Figure 17 shews the
apparatus separately, and in detail, for creating a draft in the furnace of the steam
boiler. The steam boiler is of a quadranglar figure, the four sides consisting
of a narrow water space or chamber, through the front of which are formed
openings for fire doors, and through the back one, at the upper part, are formed
holes, through which the products of combustion pass into the chimney. This
quadrangular water space is rivetted at the upper and lower parts, as is shewn,
and there are numerous stay bolts a, a, a, applied to give strength to this part
of the boiler. From this water space A, A, A, A, there are steam pipes B
into the steam chest C, which is placed above, and consists of a chamber C well
stayed by bolts c, c, c, as shewn. The water to keep up the proper supply to
the boiler is introduced at any convenient part of the outer water space A.
The stean chamber or chest C is carried by the plate D, fastened to the upper
part of the water space A, as is shewn. E is the steam pipe leading from the
steam chamber or chest C. 1 prefer the external surfaces of this boiler to be
cased in wood, as is clearly shown in some of the Figures of the Drawings F, F, F.
The upper part of the steam boiler is covered in by the cover G, which is affixed
by screw bolts and nuts. I are openings through the back part of the water
space A, for the passage of the products of combustion into the chimney If,
which chimney will be seen to be of two parts, II being the part for the passage
of the products of combustion, and II' is the part for the steam from the steam
cylinders; for in this arrangement the steam is not used as the means of obtain-
ing a strong draft in the furnace, but an apparatus hereafter described is used

page_text: within the chimney II for urging the draft. I is the furnace within the quadran-
gular water space A, and above the fire bars in the furnace 1 are applied a
series of water spaces or narrow chambers J, J, J, J, which having projectionsj
aflixed at their lowér ends, rest on the angle iron, affixed around the inside of
the furnace at K, as is shewn. These narrow water spaces are each composed
of plates of iron rivetted together all round the outer edges. And one of my
improvements consists.of the mode of connecting the water spaces J, J, to each
other, and allow of water and steam flowing from one to another. On the
outer surfaces of these water spaces J, J, are affixed a series of bars L, L
which keep the chambers separate one from the other, and allow of the heat
and products of combustion from the furnace rising up between the water
spaces J, J, there being many openings through the bars L at 1, 1, as is shown
within the chambers or water spaces J. Where they are connected there are
plates of metal rivetted to give strength and to receive the hollow screws M, M.
by which the chambers or water spaces are connected. m, m, are holes
through the pipes or screws M, and the same arrangements of hollow screws
are used for the water and steam ways between the water spaces J, J, except-
ing that the hollow screws for the steam ways are of larger diameter than those
for the water ways. On the external surfaces of the hollow screws M are formed
right and left hand screws, and Naro nuts, which, fitting on the screws M, M,
draw the water spaces J, J, together; and the water spaces J, J, are strongly
held together by means of the screw-bolts and nuts 0, 0, 0, which which passing
through the bars P, P, the whole of the water spaces J, J, are bound securely
together. Q, Q, are the steam pipes or ways which connect the upper parts
of the outer of the water spaces J, J, with the surrounding water space A, as
is shown. R is a plate, which separates the heat of the furnace from the upper
parts of water spaces J, J, and also from the steam chest or chamber C, there
being short bars L' on the upper surface of the plato R, in order to act as stays
between the water spaces J, J, as is shown. S is an axis, having a pully T
aflixed thereon, by which motion is communicated to the axis S by a band driven
by a pulley driven by the steam engine. On the upper part of this axis is affixed
the revolving frame V, which consists of a cylinder V affixed to the nave or
boss W, which is keyed to the axis S; and X, X, are a series of vanes, which
stand obliquely across the axis S, there being stops on the cylinder V against
which the oblique vanes rest, and the vanes move freely on axis, so that when
the frame is revolved in an opposite direction the vanes will fall over and
net, and thus whichever way the axis S niny be driven, by this arrange-
ment the revolution of this apparatus will cause a draft to take place in.the
furnace.

page_text: Having thus described the nature of my Invention, and the manner in which
the same is to be performed, I would have it understood that I do not confine
myself to the precise details herein described, provided the peculiar character
of either part of my Invention be retained. And I would have it understood
that what I claim is, first, the mode of constructing and applying rotatory slides
or valves to reciprocating steam cylinders, as above described.
Secondly, I claim the mode of combining water spaces J, J, in the con-
structing of steam boilers by means of hollow screws and nuts, in manner
above described.
Thirdly, I claim the application of the plate R to separate the heat of the
furnace from the steam chamber or chest C, as above described.
And, lastly, I claim the mode of constructing a revolving apparatus, with
moveable vanes capable of inclining in either direction, in order to work which-
ever way the axis is driven.
In witness whereof, I, the said John Lewthwaite, have hereunto set my
hand and seal, this Fifteenth day of August, in the year of our Lord
One thousand eight hundred and forty-two.