CERTAIN IMPROVEMENTS IN THE CON- STRUCTION OF ROTARY STEAM ENGINES
Year: 1835

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MILES
BERRY, of Chancery Lane, in the County of Middlesex, Civil Engineer and
Mechanical Draftsman, 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 Eighth day of April, in the fifth year of His
reign, and in the year of our Lord One thousand eight hundred and thirty-five,
did, for Himself, His heirs and successors, give and grant unto me, the said
Miles Berry, His especial license, full power, sole privilege and authority,
that I, the said Miles Berry, my executors, administrators, and assigns,
or such others as I, the said Miles Berry, my executors, administrators, 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 mentioned, should and lawfully
might make, use, exercise, and vend, within England, Wales, and the Town of
Berwick-upon-Tweed, an Invention of "CERTAIN IMPROVEMENTS IN THE CON-
STRUCTION OF ROTARY STEAM ENGINES," being a communication made to me
by a certain Foreigner resident abroad; in which said Letters Patent is
contained a proviso that I, the said Miles Berry, 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 had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Miles Berry, do hereby declare that the nature of the said Invention, and

page_text: in what manner the same is to be performed, is particularly described and
ascertained in and by the following description thereof, reference being had
to the Drawings hereunto annexed, and to the figures and letters marked
thereon (that is to say): :-
These improvements in rotary steam engines consist in obtaining a con-
tinuous rotary motion from the interrupted rotary motions of an engine
cylinder and engine shaft, such cylinder and shaft alternately performing a
part of a revolution in the same direction, and giving a continuous rotary
motion to a driving shaft to which they are connected by toothed wheels and
segments (that is to say):-The cylinder is made to perform part of a revolu-
tion in one direction and give a rotary motion through its toothed wheel to the
driving shaft, the cylinder turning upon the engine shaft as its axis, which at
this time is stationary, and as soon as the cylinder has completed its portion
of a revolution the engine shaft is set in motion in the same direction as the
cylinder has moved, and by its toothed wheel continues the same rotary motion
to the driving shaft, the cylinder during the movements of the shaft remaining
stationary. The movements of the engine cylinder and engine shaft are
effected by the pressure of the steam acting alternately upon pistons or steam
stops fixed to the interior of the cylinder, and on other pistons fixed on to that
part of the engine shaft which is within the cylinder, such pistons alternately
becoming moving pistons, and stationary steam stops, one to the other, and
will be fully understood by reference to the accompanying Drawings and
following description thereof.
2
Figure 1 is a plan view of the engine complete, excepting that one of the
slide valves, with. its connecting rod and the cover of the steam box or chamber,
is removed to expose the interior.
Figure 2 is an end elevation of the engine, one of the steam chambers and
slide valves also being removed to expose the other parts.
Figure 3 is a vertical section of the engine cylinder and shaft, with their
steam stops or pistons taken crosswise in Figure 1.
Figure 4 is a similar representation, shewing the pistons or steam stops in a
different position, that is, after the cylinder and its piston has moved one
quarter of a revolution; and
Figure 5 is a vertical section of one of the steam chambers and slide
valves, the same letters of reference being marked upon corresponding parts
in all the Figures.
A, A, is the cylinder, the ends or caps of which are connected steam-tight
to it in any convenient manner, and both are securely mounted steam-tight
upon the engine shaft C by proper flanges and stuffing boxes B, B, so that

page_text: the cylinder will be properly supported on the shaft, and may turn upon it as
its axis.
In Figures 3 and 4, D; D, are the pistons or steam stops of the
cylinder, to which they are firmly secured; and E, E, are the pistons or steam
stops of the engine shaft, upon which they are fixed steam-tight, and have
proper metallic or hempen packing at their ends and sides to keep the junc-
tions steam-tight, but which is not shewn in the Drawing. To one of the
stuffing boxes, B, of the cylinder, the toothed wheel F is securely attached,
and to this wheel is also firmly bolted the ratchet wheel G, and by these means
the cylinder with its toothed wheel F and ratchet wheel G, being securely
connected together, are made to revolve round the engine shaft when the
steam acts upon the pistons D of the cylinder. Upon the engine shaft C is
securely mounted the toothed wheel H and the ratchet I, so as to revolve with
it when the steam acts upon the pistons E of the engine shaft, which shaft is
mounted in proper plummer boxes or bearings K, K, in the framework L, L.
M is the driving shaft, or that which receives its continuous rotary motion
from the interrupted rotary motions of the cylinder and engine shaft. The
driving shaft is also mounted in proper bearings or plummer boxes in the
framework L, and has the two toothed wheels or segments N and O securely
mounted upon it, which wheels or segments have teeth formed only one half
of their circumference. N is the segment which takes into the teeth of the
wheel F of the cylinder, and O the other segment, which gears into the
wheel H of the shaft, and these segments are so placed upon the driving shaft
that when one of them is in gear with its fellow toothed wheels F or H, the
other will be out of gear with its corresponding wheel, and by these means the
continuous rotary motion of the driving shaft is obtained; for when the
toothed wheel F of the cylinder is in gear with the segment N, the toothed
wheel H of the shaft will be out of gear with the segment O, and when this
segment is in gear with its corresponding wheel, the other segment will be out
of gear with its wheel. P, P, are strong palls or click stops, which take into
the notches of the ratchet wheels G and I, and prevent the cylinder and
engine shaft from turning round but in one direction when the steam is acting
upon the pistons of either the cylinder or shaft, and by thus preventing the
pistons of the cylinder and engine shaft from turning backwards, cause the
pistons alternately to form steam stops or abutments to the elastic force of
the steam acting upon each other. These palls or stops, P, P, are mounted
by joints upon strong rods or levers Q. Q, having their fulcrums at one of their
ends in joints screwed into the bottom or foundation plate of the engine, the
other ends of the levers being kept up by springs and adjusting screws, which
allow a sufficient motion or play in the levers for the palls to clear the ratchets

page_text: of the wheels G and I, and enter properly into contact with them, the palls
being kept in close contact with the periphery of the ratchet wheels by springs
pressing against them, as shewn in Fig. 2.
Having now described the arrangement and construction of the various
parts of the engine, I shall proceed to describe how the steam is admitted to
the interior of the cylinder, and the induction and eduction passages opened
and closed to effect the proper action of the engine.
It will be seen by Figures 3 and 4 that the pistons or steam stops D and E
divide the interior of the cylinder into four portions or chambers R, R, and
S, S. The two chambers R, R, have no communication with the others, S, S,
but the two first communicate one with the other through steam channels or
passages a, a, formed through the engine shaft, and the two latter by similar
passages b, b, (shewn by dots,) also passing through the shaft, which passages
alternately form the induction and eduction steamways of the engine. Steam
is admitted into the interior of the cylinder through the shaft C, which is
hollow, being bored longitudinally from its extremities inwards nearly through-
out its whole length, there being a small part left solid in the middle between
the passages a and b. The hollow passage of one end of the shaft com-
municates with the steam passages a, a, and that of the other end with the
steamways 6, 6, (as shewn by the red dotted lines in Figure 1,) and by this
disposition of the pistons and steam passages any engineer will easily under-
stand how the chambers R, R, and S, S, may be made, by means of proper
slide valves placed at the end of the shaft C, to communicate alternately with
I will therefore
the steam generator or condensor, or to the atmosphere.
proceed to describe the action of the engine, and one arrangement for effecting
the change of the induction and eduction passages, and the working slide
valves, but which will admit of considerable variation, as the proper move-
ments of the slide valves may be obtained in various ways.
T and U are two chambers or boxes mounted on brackets projecting from
the end frames of the engine, in which boxes the slide valves work, and are
supplied with steam through the pipes c, c, leading from the generator. d is
the slide valve working over the alternately induction and eduction passage e,
(see the detached Figure 5,) which communicates with another cylindrical
steam chamber f, from whence pipes 9, 9, extend to the hollow longitudinal
passages in the engine shaft C. These pipes 9, 9, are closed at their outer
ends, but have slots or openings in them within the chamber f, and are con-
nected steam-tight to these chambers by passing through stuffing boxes, in
which they revolve, and also to the shaft C by proper packing, and being fixed
on the ends of the shaft revolve with it, and they should be placed in a direct.
h

page_text: line with its axis. i, i, are the exit pipes or passages for the eduction steam,
which may lead off to a condensor, or to the atmosphere.
Supposing the pistons of the engine to be in the position shewn in Figure 3,
that is, with the chambers R, R, open to the steam generator by the
passages a, a, and the chamber S, S, open to the condensor or atmosphere
through the passages b, b, the steam on being admitted by the slide valve, as
herein-after described, passes along the hollow passage of the engine shaft
through the openings a, a, into the chambers R, R, where exerting its ex-
pansive power against both the pistons D and E forces the former round with
the cylinder one quarter of a revolution in the direction of the arrows, that is,
into the position shewn in Figure 4, the other pistons E of the engine shaft
resisting the force of the steam, they being prevented from turning round the
reverse way by the palls or stops P taking into the ratchets of the wheel I.
As soon as the pistons D arrive in this position, that is, at the end of one
quarter of a revolution, the steam passages are changed by the slide valve, the
steam being admitted into the chambers S, S, through the passages b; at the
same time the steam in the chambers R, R, is free to make its escape through
the passages a, a, (which now become the eduction passages) to the condensor
or the atmosphere. The steam now exerts its expansive force in the
chambers S, S, and as the pistons D are prevented from turning back by
the palls or stops P taking into the ratchets of the wheel G, the pistons E are
forced round in the direction of the arrow one quarter of a revolution (that
is, following the pistons D), when another change of the slide valves takes
place, and the passages 6, 6, again become the eduction passages, and the
passages a, a, the induction, and the cylinder, with its pistons, is again made
to move forward one quarter of a revolution, when another change in the
slides take place, and the pistons E again move, and so on, producing alter-
nately an interrupted rotary motion of the cylinder and engine shaft in one
direction, which motion is communicated by the toothed wheels F and I to
the working shaft, as before stated, and from its segments or wheels N, O,
being only half the diameter of the wheels F and H, the driving shaft con-
sequently makes two rotations to one of the engine. A fly wheel should be
placed on the working shaft to render its motion regular and continuous during
the time the engine is on the dead points, that is, while the slide valves are.
changing the steam passages. The motion of the slide valves in the chambers
T and U is obtained in the following manner :-k, k, are the slide valve rods
which work through stuffing boxes and guides, and are connected at the outer
ends by joints to the ends of the lever 1, turning upon a pin or stud ; as its
fulcrum. The ends of this lever are alternately moved outwards and inwards,

page_text: thereby changing the position of the slides by cams or tappets n, m, and
n*, m, mounted on opposite ends of the working shaft m, which cams act
against the ends of the sliding bars o, o, the other ends of the bars being con-
nected by joints to the ends of the lever 1, and thus as the working shaft
revolves the slide valves will be moved, and change the steam passages at the
proper times.
In order that the engine may be worked with the steam ex-
panding, that is, when the passage of the induction steam into the engine is cut
off before the pistons have performed their full quarter of a revolution, the
tappets n, m, and n*, m*, are so placed upon the shaft M that when the
larger tappet n has forced one end of the lever outward and caused the slide valve
at its end of the shaft to admit the steam into the engine (as seen in Figure 5),
and as soon as sufficient steam is admitted to the cylinder, then the smaller
tappet m, (shewn by dots in Figure 2,) at the other end of the shaft, coming
into contact with its rod o, forces the lever and slide partly back again into
the position shewn in the diagram Figure 6, and cuts off the supply of steam,
the slide valve covering the aperture e. The steam in the cylinder then ex-
panding continues the motion of the shaft M, until the larger tappet n, comes
into contact with its slide bar o, when its slide d will be brought into the
position shewn in Figure 5, and the slide at the other end of the engine
brought into the position shewn in the diagram Figure 7, that is, opening the
passage to the exit pipe i, when the eduction steam is free to go off to the
condensor or atmosphere, and these movements taking place at each end of the
engine, the continuous motion is effected. I would here remark, that as the
steam does not enter the cylinder at the very moment the pistons of the shaft
and engine finish their movements, it might happen that they would perform a
little more than their proper portion of a revolution, and if this should take
place on the next entrance of the steam, they would have to recede, which
would produce a concussion in the engine; this inconvenience is provented by
the application of each of the toothed wheels F and I, of four projecting stop
pieces p. p, p, p, which come into contact with the lever 1, at the moment the
pistons of the cylinder or engine shaft have completed their quarter of a
revolution, and which are released by the movement of the lever at the
moment the toothed wheels F and H, and their pistons, are on the point of
starting.
In witness whereof, I, the said Miles Berry, have hereunto set my hand
and seal, this Eighth day of October, in the year of our Lord One
thousand eight hundred and thirty-five.
MILES (L.s.) BERRY.

page_text: AND BE IT REMEMBERED, that on the Eighth day of October, in the
sixth year of the reign of His Majesty King William the Fourth, the said
Miles Berry came before our said Lord the King in His Chancery, and
acknowledged the Instrument aforesaid, and all and every thing therein con-
tained and specified, in form above written. And also the Instrument
aforesaid was stamped according to the tenor of the Statute made in the
fifty-fifth year of the reign of His late Majesty King George the Third.
Inrolled the Eighth day of October, One thousand eight hundred and
thirty-five.