IMPROVEMENTS IN ROTARY STEAM ENGINES
Year: 1859

page_text: LETTERS PATENT to William Edward Newton, of the Office for Patents,
66, Chancery Lane, in the County of Middlesex, Civil Engineer, for
the Invention of "IMPROVEMENTS IN ROTARY STEAM ENGINES."-A com-
munication from abroad by Charles Smith Hathaway, of Athol, Thomas
Huston Witherby, and Luke Bucklin Witherby, both of Worcester, and
Jonathan Horatio Nelson, of Shrewsbury, all in the County of Worcester,
and State of Massachusetts Tinited States of Ameri
PROVISIONAL SPECIFICATION left by the said William Edward Newton
at the Office of the Commissioners of Patents, with his Petition, on
the 17th October 1859.
I, WILLIAM EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane,
in the County of Middlesex, Civil Engineer, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN ROTARY STEAM ENGINES" to be
as follows:-
This Invention of improvements in rotary steam engines relates to that class
of rotary engine in which the cylinder only extends a portion of the way round
the main shaft. One of the ends of the cylinder of such an engine, if the
engine is only intended to run one way, or each end, if it is intended to run
both ways, is fitted with a moveable head, which serves as an abutment as well
as an exhaust valve; and the present Invention consists in certain mechanism

page_text: for operating the moveable head or beads, to make it or them close the
cylinder after the entry of the piston, and withdraw it or them to permit the
steam to be exhausted after having done its work. The cylinder extends
about three-fourths of the way round the main shaft, and has its steam channel
of circular form in its transverse section. A circular piston fits to the circular
steam channel, and is suitably packed to make it work steam-tight therein.
The piston is firmly secured to a hub that is keyed to the main shaft; a box
which is termed the exhaust box surrounds and supports the cylinder, and is
provided with an exhaust steam pipe. The main shaft passes through stuffing
boxes in the sides of the cylinder and other stuffing boxes in the sides of the box
or envelope of the cylinder. This shaft is supported in bearings in two standards
outside of the box or envelope. The cylinder is provided with moveable
heads, one fitted into each of the two mouths of the cylinder, with suitable
packing to make them steam-tight. One cylinder head is attached to a cross
head, which is fitted to slide in two parallel arms which are radial to the main
shaft, but are fitted loosely to the said shaft, so that they will not interfere
with or be interfered with by the rotation of said shaft. A rock shaft is
arranged parallel with the main shaft in bearings, and has rigidly attached to
it two arms or levers, one of which is connected with the crosshead, which is
also connected with a forked arm arranged to vibrate on a fixed pin secured to
the cylinder or the envelope. The other cylinder head is attached rigidly to a
short arm, which branches off from the arm of the rock shaft. Another arm
of the rock shaft is fitted with a slide, on the sides of which are journals, by
which it is connected with the connecting rod of an excentric that is fast on
the main shaft. The steam chest of the engine is supplied constantly with
steam. A slide valve works in this chest, and serves to effect the induction of
the steam to the cylinder, and to cut it off at such point in the revolution of
the piston as may be desired, and also serve as a reversing valve. This valve
consists of a simple flat plate without port or cavity, and it works against a
flat seat in which are two ports, one leading directly to the cylinder near one
of the mouths, and the other one communicating with the cylinder near the
other mouth. The stem of the valve is connected by a rod with one arm of a
three-armed lever, which works up on a fixed fulcrum. The other arms of the
said lever are so situated, that the friction rollers which they carry may be
operated upon by two cams on the main shaft; but these arms are so far apart
that only one can be operated upon at once. The change of operation of the
arms is effected by means of a hand lever, which contains a notch for the
reception of a stud on the rod of the slide valve. This lever is also furnished
with another stud, which is capable of being sprung into holes in a stationary

page_text: When the stud on the slide valve rod is in the lowest hole of the are,
the lever is allowed to assume such a position that the arm is acted upon by
the cam to cause the opening and closing of the upper port of the valve, the
other port being left closed; but when the stud is in the highest hole, reverse
action takes place. The moveable heads of the cylinder both remain stationary,
or at least very nearly so within the two mouths of the cylinder, while the
piston makes about a little more than half a revolution about the axis of the
main shaft within the cylinder; but as the piston arrives near each mouth of
the cylinder, the heads are withdrawn and moved out of the way to let the
piston pass them.. When the cylinder heads are in the mouths of the cylinder,
the toggle whereby they are connected with the rock shaft is straight, and the
rise of the arm produces a flexure of the toggle, which first-draws the cylinder
heads from the cylinder, and then raises them out of the path of the piston..
One of the heads is moved in an are described from the centre of the rocking.
shaft, but the other head, after being withdrawn from the cylinder; is lifted up
in a direction almost radial to the centre of the cylinder by the crosshead.. The
movement of the toggle is so controlled by the connection of the crosshead
with the arm, that as the flexure of the toggle commences it draws the heads
out of the cylinder,. and then moves the crosshead quickly up, and so lifts thé
heads out of the path of the piston. Immediately after the piston has again
entered the cylinder, the toggle is gradually straightened, and the return of
the heads into the cylinders is effected..
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Edward Newton in the Great Seal Patent Office
on the 17th April 1860..
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
EDWARD NEWTON,. of the Office for Patents, 66, Chancery Lane, in the County
of Middlesex, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeenth day of October, in the year of our
Lord One thousand eight hundred and fifty-nine, in the twenty-third year
of Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said William Edward Newton, Her special license that I, the said
William Edward Newton, my executors, administrators, and assigns, or such
others as I, the said William Edward Newton, my executors, administrators,
and assigns, should at any time agree with, and no others, from time to time

page_text: and at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United Kingdom
of Great Britain and Ireland, the Channel Islands, and Isle of Man, an In-
vention for "IMPROVEMENTS IN ROTARY STEAM ENGINES," being a communication
from abroad, upon the condition (amongst others) that I, the said William
Edward Newton, by an instrument in writing under my hand and seal,
should particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the same to
be filed in the Great Seal Patent Office within six calendar months next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Edward Newton, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the Drawing hereunto annexed,
and to the letters and figures marked thereon (that is to say) :-
This Invention of improvements in rotary steam engines relates to that
class of rotary engine in which the cylinder only extends a portion of the way
round the main shaft. One of the ends of the cylinder of such an engine, if
the engine be only intended to run one way, or each end if it be intended to
run both ways, is fitted with a moveable head, which serves as an abutment
as well as an exhaust valve; and the present Invention consists in certain
mechanism for operating the movable head or heads to make it or them close
the cylinder after the entry of the piston, and withdraw it or them to permit
the steam to be exhausted after having done its work.
In the accompanying Drawing, Fig. 1 is a vertical section, parallel with
the plane of rotation, of an engine constructed according to the present
improvements; Fig. 2 is a central vertical section of the same, taken in a
line parallel with the axis of rotation; Fig. 3 exhibits a side view of the cams
for operating the valves. Similar letters of reference denote like parts in each
of the several Figures.
A is the cylinder, extending about three-fourths of the way round the main
shaft C, as shown in Fig. 1, and has its steam channel s, s, of circular form
in its transverse section, as shewn in Fig. 2; D is a circular piston, fitting
to the circular steam channel s, s, and is suitably packed to make it work
steam-tight therein. The piston is firmly secured to a hub a that is keyed to.
the main shaft C. B is a box, which is termed the exhaust box; it surrounds
and supports the cylinder, and is provided with an exhaust steam pipe B*
(Fig. 1), which is attached to the box B. The main shaft C passes through
stuffing boxes c, c, in the sides of the cylinder A, and other stuffing boxes d, d,

page_text: in the sides of the box or envelope B of the cylinder. This shaft is supported
in bearings b, b, in two standards E, E, outside the box or envelope B. The
cylinder is provided with movable heads F, F*, fitted into each of the two
mouths of the cylinder with suitable packing to make them steam-tight. One
cylinder head F is attached to a crosshead G, which is fitted to slide on two
parallel arms H, H, placed radially to the main shaft C, but fitted loosely to
the main shaft G, so that they will not interfere with or be interfered with by
the rotation of the said shaft. I is a rock shaft, arranged parallel with the
main shaft C in bearings placed on the top of the box B, and having rigidly
attached to it two arms or levers J, K. The arm J is connected at its
extremity by a joint pin e with a link L, which is connected with the cross-
head G. The arm J and link L combined constitute a toggle. The cross
head is also connected with a forked arm M, which is arranged to vibrate on
a fixed pin f, secured to the cylinder or to the box B. The arm M is curved,
The cylinder head F*
to allow it and the cylinder head F to clear each other.
is attached rigidly to a short arm J", which branches off from the arm J of
the rock shaft I, the arms J and J* being connected together in a perfectly
rigid manner. The arm K of the rock shaft I is fitted with a slide N, on the
sides of which are journals g, g, by which it is connected with a lever P, which
works on a stationary piu h, and is connected with the connecting rod Q of an
excentric R that is fast on the main shaft. The steam chest S of the engine
is supplied constantly with steam from the boiler by the pipe U. T is a slide
valve working in this chest, and serving to effect the induction of the steam
to the cylinder at the proper time, and to cut it off at such point in the
revolution of the piston as may be desired, and also serving as a reversing
valve. This valve consists of a simple flat plate, without port or cavity, and
it works against a flat seat i, i, in which are two ports j, j*, the former leading
directly to the cylinder near the mouth which receives the head F, and the
other one communicating by a passage k running round the outside of the
cylinder with the cylinder near the mouth which receives the head F*.
The stem of the valve s is connected by a rod m with one arm o of a three-
armed lever o, p, p*, which works upon a fixed fulcrum n, as shown by dots
in Fig. 1. The other arms p, p, of this three-armed lever are so situated,*
that the friction rollers q, q*, which they carry may be operated upon by two'
cams t, t, on the main shaft C, the cam t being arranged. to operate upon
the roller g of the arm p, and the cam t* arranged to operate on the roller q*
of the arm p, but these arms are so far apart that only one can be operated
upon at once. Fig. 1 represents the cam t in operation on the arm p, and
represents the arm p* in an inoperative condition. The cam t, by its operation

page_text: on the arm p, moves the valve T in such a manner as to open and close the
port j, leaving the port j* always closed; but the cam *, by its operation on
the arm p* moves the valve in such a manner as to open and close the port j*,
leaving always closed. The change of operation of the arms is effected by
means of a hand lever W (Fig. 1), which works on a fixed fulcrum v, and
contains a notch, for the reception of a stud w on the rod m of the slide
valve. This lever is also furnished with another stud a, which is capable of
being sprung into either of three holes y, y', y², in a stationary arc X. The
weight of the valve T, and stem l, and the rod m, aided by a portion of the
weight of the lever o, p, p*, causes the stud w to drop into the notch z when
the valve is not held up. When the stud a is in the lowest hole y, as shewn
in the Drawing, the lever o, p, p, is allowed to assume such a position that
the arm p is acted upon by the cam t, to cause the opening and closing of
the upper port j and the port j* is left closed; but when the said stud x is
in the highest hole y², the arm p* is in position to be operated upon by the
cam t, so as to cause the opening and closing of the port j", and the port j
is kept closed; and when the stud x is in the middle hole y', the lever W
keeps the lever o, p, p*, in such a position that neither cam will act upon it,
and it will hold the valve T in a position to close both ports and stop the
engine.
The movable heads F, F, of the cylinder both remain stationary, or at
least very nearly so, within the two mouths of the cylinder, while the piston
makes about a little more than half a revolution about the axis of the main
shaft within the cylinder; but as the piston arrives near each mouth of the
cylinder the heads are withdrawn and moved out of the way to let the
piston pass them. This operation is effected entirely by the oscillating
movement of the rock shaft T, produced by the action of the excentric R,
lever P, and slide N, upon the arm K, the movement of the lever P derived
from the excentric causing the slide to work back and forth along the arm.
When the cylinder heads are in the mouths of the cylinder, the toggle J, L,
is straight, and the rise of the arm L produces a flexure of the toggle, which
first draws the heads F, F, from the cylinder, and then raises them out of
the path of the piston. The head F* is moved in an arc described from the
centre of the shaft I, but the other head F, after being withdrawn from the
cylinder is lifted up in a direction almost radial to the centre of the cylinder by
the crosshead G, which, when carrying it, slides up the arms H, H. At the
time of the two heads being brought within the mouths of the cylinder by the
straightening of the toggle J, L, the lever P, slide N, and arm K, are in the
relative positions shown in black outline in Fig. 1, and the part of the arm K

page_text: beyond the slide N, is in a position coinciding as nearly as it can with the arc
described by the extremity of the lever P, so that the lever in being moved
by the excentric to carry the slide from this position toward the end of the
arm K and back again, scarcely moves the said arm on the rock shaft I, and
consequently leaves. the heads F, F*, so nearly stationary that their move-
ment is hardly perceptible, and no steam is permitted to pass the one on the
steam side of the piston; but as the slide N is caused to approach nearer to
the rock shaft it causes a depression of the arm K, and causes the arm J to
be raised, and the toggle to be bent. Now the movement of the toggle is so
controlled by the connection of the crosshead G with the arm M, that; as the
flexure of the toggle commences it draws the heads out of the cylinder, and
then moves the crosshead G quickly up the arms H, H, and so lifts the head
F as well as. F* out of the path of the piston, the mechanism for operating the
heads then being in the position shown in red outline. Immediately after the
piston has again entered the cylinder the slide N.commences to return along
the arm K, and to depress the said arm, and by that means to cause the
gradual straightening of the toggle and the return of the heads into the
cylinders. In working the engine in the direction indicated by the red arrow in
Fig. 1, the head F constitutes the abutment for the steam and also the exhaust
valve, and the head F* performs no duty at all. In working in the other
direction the head F* does duty, and the head F no duty at all, though both
are always in operation. In engines for working only one way the head F*
may be entirely dispensed with. The valve gear for working the valve T is so
adjusted as to admit steam by the port j or j to the cylinder close to the
head For F; suppose F, for the sake of example, immediately after the
piston has entered the cylinder, and the head has closed the cylinder behind it.
The valve may close the port at any point in the movement of the piston that
will allow time for the heads to be subsequently removed in time to prevent the
piston from coming in contact with them, and the port is not opened again
till the piston has passed round and entered the cylinder again, and the head
has been closed behind it. The steam is exhausted from the cylinder into the
exhaust box B by the opening of the head, and escapes from the exhaust box
by the pipe B*. It is proposed generally to cut off the steam when the piston
has made only a portion of its movement through the cylinder, and to complete
the movement by its expansive force.
It will be obvious to the engineer that unless this kind of engine is to make
a portion of its revolution by the momentum of a fly-wheel, two cylinders
must be employed so that one piston may always be subject to the action of
the steam.

page_text: Having now described the Invention that has been communicated to me
as aforesaid, and. having explained the manner of carrying the same into
effect, I claim the combination of the crosshead G (or its equivalent which
carries the cylinder head F), the rock shaft I, the toggle J, L, and the
vibrating arm M, the whole applied and operating substantially as described
in combination with the guide arms H, H, for the purpose herein set forth.
In combination with the above-mentioned rock shaft I also claim the
arm K, the slide N, the lever P, and the excentric applied to produce an
intermittent motion of the said rock shaft, as herein set forth.
In combination with the use of the mechanism herein described, which
operates the movable cylinder head F, I further claim the attachment of the
cylinder head F* to the arm K of the rock shaft I.
In witness whereof, I, the said William Edward Newton, have hereunto
set my hand and seal, the Sixteenth day of April, in the year of our
Lord One thousand eight hundred and sixty.
Witness,
J. W. MOFFATT,
66, Chancery Lane.
W. E. NEWTON. (L.S.)