IMPROVEMENTS IN ROTATORY ENGINES, OR AN IMPROVED ROTATORY ENGINE
Year: 1836

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN YULE,
of Sanchiehall Street, Glasgow, Practical Engineer, send greeting.
WHEREAS His present most Excellent Majesty King William the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Fifteenth day of November, in the seventh year of His
reign, did, for Himself, His heirs and successors, give and grant unto me, the
said John Yule, His especial licence, full power, sole privilege and authority,
that I, the said John Yule, my exors, adñiors, and assigns, or such others as I,
the said John Yule, my exors, adiñors, 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 ROTATORY ENGINES, OR AN IMPROVED ROTATORY
ENGINE;" in which said Letters Patent is contained a proviso that I, the
said John Yule, 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 His 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 Yule, do hereby declare that the nature of my Invention, and the
manner in which the same is to be performed, are fully described and ascer-
tained in and by the following statement thereof, reference being had to the

page_text: Drawings hereunto annexed, and to the figures and letters marked thereon,
that is to say :-
My Improvements in Rotatory Engines or Improved Rotatory Engine consists
of an external large hollow cylinder containing an eccentric wheel or cylinder of
a diameter considerably smaller. This eccentric wheel or cylinder is fixed upon
a shaft parallel to its centre, but at a distance from the centre. The shaft of
the said eccentric wheel, drum, or cylinder is the axis upon which it revolves,
and the distance betwixt the centre of the shaft or axis to the farthest
extremity of the circumference of the said eccentric wheel is exactly equal to
the radius of the large cylinder. The said shaft or axis of the eccentric wheel
passes through the centre of the covers, which are bolted or otherwise secured
upon the ends of the large cylinder, which covers bear closely upon the ends of
the said inner eccentric wheel or drum. The eccentric wheel acts as the piston
of the engine, and when made to revolve touches the inner circumference of the
large cylinder with the farthest extremity of its circumference at every part of
its revolution. There is a slide passed into the large cylinder from the outside.
This slide touches upon the circular piston throughout the whole length of the
revolution of the inner cylinder or piston by means of connecting rods or links
being attached to crank pins affixed on cog wheels, which are keyed upon
each end of the shaft or axis of aforesaid eccentric wheel or cylinder. These
said links are attached to a cross bar or cross head, which is cast or otherwise
fixed upon the slide or steam abutment, and stop part of the slide projects above
or beyond the said cross head, and works in a fixed socket, so that the move-
.ments of the slide are always in a straight line. Below the cross head, guides
or bearers are fixed, which guides are made to bear upon friction wheels,
these friction wheels in a great measure taking away the friction occasioned by
the lateral pressure of the steam or other power upon the blade, the slide
forming the principal abutment or resting point for the steam or other power..
I shall now endeavour to explain more particularly the manner and operation
of the engine; but before doing so I may merely state, that the same principle
of rotatory engine may be employed in several other different shapes. Instead
of letting the steam in and out from the circumference of the large cylinder, it
might be let in and out from its centre, passing into one end of the shaft
or axis of the eccentric wheel and out at the other.
DESCRIPTION OF THE DRAWINGS.
Figure 1 represents a transverse section of the engine cut through at
Figure 4. Figure 2 is a longitudinal section cut through at æ, Figure 3.
T
2 is an and view of the engine Figure 4 is an elevation or side view

page_text: Figure 5 is a steam valve for shutting off the steam when the eccentric is on
the centre. Figure 6, bird's-eye view of large cylinder with steam pipes, and
other apparatus disconnected. Figure 7, eccentric cylinder blade and guides
by themselves. Figure 8, an end view of eccentric cylinder blade and guides.
Figure 9, front and edge view of cylinder cover by themselves. The same
figures denote the same parts in each different view. The red color in
Figure 1 is the fresh steam from the boiler; the blue colour is the waste steam
ór steam exhausting. A, A, is the large or outer cylinder; B, B, the eccentric
wheel or eccentric cylinder; C, the axis or shaft on which the eccentric wheel
is affixed; D, the slide; E, a part of the slide projecting above the cross
bar F, as seen in Figure 2, and working in the fixed socket a; b, b, the steam;
c, c, the exhausting pipes; d, d, slide valves capable of covering from the
steam either one or two of the steam ports e, e, f, f, as may be required;
e, e, is covered from the steam immediately from the boiler, and the valve is
shaped so as to allow the steam to exhaust in the direction of the arrows
through the ports e, e, while the other valve d is pulled to the position it now
is in covering only one port f, leaving the other port f open for the steam to
pass into the large cylinder in the direction of the arrows (the slide D dividing
the space y, y, into two compartments in the present position of the engine);
9, packing to keep the whole length of the circumference of the farthest
extremity of the eccentric wheel or drum steam tight; H, H, a part of the
guides carried down from the cross head upon each end for the purpose of
connecting the links j, j, to the cross F, F, and crank pins h, h, as seen
in Figures 3 and 4; L, throttle valve; M, a gridiron, steam, or stop valve,
which shuts off the steam by means of the top part of the blade B pressing up
the lever N; the elasticity of the spring, which is seen in the Drawings, opens
the valve as the blade recedes from it. This valve is necessary, as both steam
ports and exhausting ports are open to each other when the engine is upon the
centre, or when the end of the slide is opposite or touching the packing g of the
eccentric wheel or drum; the springs are seen at back of the packing g of the
eccentric wheel, which presses forward the packings as the were requires it;
o, o, are the packings for keeping the slide steam tight. These packings are
placed in the cylinder cover, and are pressed out also by springs, as is seen in
the Drawing. The point of the slide or steam stop where it touches the
eccentric cylinder is kept steam tight by the circular-sided packing 'p, which
has springs at the back of it to keep it closely bearing upon the eccentric
wheel at every part of its revolution. The blade or slide is packed with hemp
in the same manner as the piston rod of reciprocating engines, as may be seen
in the Drawings, or metallic packing may be used for the same purpose.

page_text: Sheet 2 shows the inner or eccentric piston made in various shapes, though
not differing in principle, Figure 4 being of the same form as in Sheet 1.
In Figures 5 and 6 the links are attached directly to the cross head of
the blade, in which case it will be necessary that the piston should be of an
elliptical form. The line x in the Figures 4, 5, 6, represents the links.
The weights y, y, in Figures 7, 8, 9, 10, force down the packings a, a, a, at
all times, rising and falling as the shape of the inner cylinder or piston may
require.
Having thus described the nature of my Invention, and the combining the
various parts, I would have it understood that I lay no claim to any of
the parts separately nor in combination other than is hereafter particularly
pointed out and claimed as new combinations of mechanical parts of rotatory
steam engines. What I claim as my Invention is,―
First, the affixing of the inner cylinder to the shaft or axis C, and thus
transmitting the power of steam or other vapour, air, or fluid acting on the
eccentric cylinder to the purposes desired, such eccentric cylinder acting as the
piston, as above described.
And, secondly, I claim the mode of working the slide D by means of crank
pins or cranks and links j, and rods H applied to the shaft C, as above
described, by which the slide D is at all times retained in a correct position
for making a steam-tight division of the compartments y, y, as above described.
Thirdly, I claim the peculiar arrangement of valves and steamways d, d, e, e,
ff, and c, c, as above described.
In witness whereof, I, the said John Yule, have hereunto set my hand
and seal, this Fifth day of May, in the year of our Lord One thousand
eight hundred and thirty-seven.

page_text: Lang, a Justice of the Peace for the County of Lanark, in the Kingdom of
Scotland, and the signature to the acknowledgment of John Yule's Specifi-
cation is in the handwriting of the said John Lang. And this deponent
further saith, that the said John Lang was, at the time of receiving such
acknowledgment, a Justice of the Peace for Lanark, and that he was autho-
rized to administer such acknowledgment.