IMPROVEMENTS IN THE CONSTRUCTION OF STEAM ENGINES
Year: 1873

page_text: LETTERS PATENT to William Eli Sudlow, of Oldham, in the County
of Lancaster, Engineer, for the Invention of "IMPROVEMENTS IN
THE CONSTRUCTION OF STEAM ENGINES."
PROVISIONAL SPECIFICATION left by the said William Eli Sudlow at
the Office of the Commissioners of Patents, with his Petition, on
the 23rd January 1873.
I, WILLIAM ELI SUDLOW, of Oldham, in the County of Lancaster,
Engineer, do hereby declare the nature of the said Invention of “IM-
PROVEMENTS IN THE CONSTRUCTION OF STEAM ENGINES," to be as follows :—
This Invention has for its object the construction of a steam engine,
which is designed to obviate the disadvantage of the dead centres or
points and the ever varying leverage in a crank, and consequent loss of
power in a reciprocating piston connected to such crank, and consists in
arranging a number of drums upon a shaft, cach of which drums
revolves in a suitable casing (through stuffing boxes) of larger internal

page_text: diameter than the drum, so as to afford an annular space round the
periphery of such drum. Into this space a plato radiating from the
periphery of the drum projects, and at one point in the circumference of
the annular casing a slide containing ports and a slide valve is caused
by suitable mechanism to work up and down, so as temporarily to divide
the space between the drum and annular casing into two compartments,
in one of which the steam pressure is admitted through the ports in the
slide herein-before mentioned, and the other compartment is open to the
atmosphere, or is in communication with an air pump and condenser.
The slido hercin-before mentioned is caused by an eccentric to move out
of the way after first closing the steam port as the plate on the periphery
of the drum approaches it in its revolution, and to return to the closed
position as gradually and as soon as such plate has passed it, when tho
steam port is instantly opened again. This construction of rotary engino
permits of the steam being used expansively to better advantage than is
possible with a reciprocating piston in a cylinder, and by having several
of these drums and casings upon the same shaft the steam is always
exercising its full power upon the drums without the disadvantage of
the dead points, and the full leverage is maintained during the entire
revolutions of the drums.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Eli Sudlow in the Great Scal Patent
Office on the 23rd July 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ELI SUDLOW, of Oldham, in the County of Lancaster, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-third day of January, in the
year of our Lord One thousand eight hundred and seventy-three, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,
give and graut unto me, the said William Eli Sudlow, Her special
licence that I, the said William Eli Sudlow, my executors, admi-
nistrators, and assigns, or such others as I, the said William
Eli Sudlow, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time and at

page_text: 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, tho Channel Islands, and Islo
of Man, an Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF STEAM
ENGINES," upon the condition (amongst others) that I, the said William
Eli Sudlow, 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
samo to be filed in the Great Scal Patent Office within six calendar
months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, tho said William Eli Sutton, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement :-
This Invention has for its object the construction of a steam engine,
which is designed to obviate the disadvantage of the dead centres or
points and the over varying leverage in a crank, and consequent loss of
power in a reciprocating piston connected to such crank, and consists in
arranging a number of drums upon a shaft, each of which drums
revolves in a suitable casing (through stuffing boxes) of larger internal
diameter than the drum, so as to afford an annular space round the
periphery of such drum. Into this space a block upon the periphery of
the drum projects, and at one point in the circumference of the annular
casing a slide containing ports and a slide valve is caused by suitable
mechanism to advance and recede, so as temporarily to divide the space
between the drum and annular casing into two compartments, in one of
which the steam pressure is admitted through the ports in the slide herein-
before mentioned, and the other compartment is open to the atmospherc,
or is in communication with an air pump and condenser. The slide
herein-before mentioned is caused by an eccentric to move out of the
way after first closing the steam port as the block on the periphery
of the drum approaches it in its revolution, and to return to the closed
position as soon as such block has passed it, when the steam port is
instantly opened again. This construction of rotary engine permits of
the steam being used expansively to better advantage than is possible
with a reciprocating piston in a cylinder, and by having several of these
drums and casings upon the same shaft the steam is always exercising

page_text: its full power upon the shaft which receives motion from the drums
without the disadvantage of the dead points, and the full leverage is
maintained during the entire revolution of the drums.
Without HC disadvantage of
maintained during the entire revolution of the drums.
In order that this my said Invention may be the more readily seen and
understood I have hereunto annexed two Sheets of Drawings illustrative
of my improvements.
Fig. 1 is a plan partly in section, and Fig. 2 is a side sectional view of
a steam engine constructed according to my Invention, and drawn to a
scale of about one-fourth full size. A, A, are two cast-iron cylindrical
chambers, herein-after called cylinders, firmly secured upon the base
plate B by the bolts C. As the internal construction and method of
working both these cylindors is the same I will confine my description
to one of them, and will herein-after speak of the cylinder in the singular
number, it being understood that one, two, three, or more such
cylinders may be employed, according to the power required, and the
extent to which the steam is used expansively. The cylinder A is
bored out to a truc cylindrical surface to receive the revolving drum
herein-after described, and such cylinder is enclosed at each end by the
cover plates D secured in position by the set screws E. A space F is
formed partially surrounding the cylinder A, which serves the double
purpose
of a steam jacket, and an exhaust for the steam which escapes
into such space from the interior of the cylinder through the passage F',
and finally escapes by the exhaust pipe F; G is a shaft mounted in
bearings in the pedestals G', and passing through the centre of the
cylinder A through the stuffing boxes G₁ formed in the cover plates D.
Inside the cylinder A the shaft G carries the drum H, which is provided
with disc plates or flanges H' securely fastened at each end, the edge or
periphery of which plates or flanges revolve in anuular recesses H³
formed partly in the ends of the cylinder, and partly in the cover
plates D, as illustrated. The drum H is not keyed rigidly to the shaft G,
but is mounted upon an intermediato boss II³, which has keys I affixed
by set screws upon its periphery which fit into slots formed in the drum,
and so ensure such drum revolving with the shaft, but permit such shaft
to expand lengthwise when it becomes heated without at the same time
causing the drum to tighten against the ends of the cylinder, a space J
being left between cach extremity of the boss H³ and the corresponding
cover plate to allow for such expansion; K is a block projecting

page_text: from the periphery of the drum H, the outer edge of which block is
turned to the same curve as the bore of the cylinder, so that as the
drums revolves within the cylinder such block forms a steam-tight joint
with the curvilinear surface of the cylinder, and this tightness may be
still further ensured by the application of the spring packing piece L,
which is acted upon at the back by the steam entering through the
small passage M, and overcoming the strength of the spring N, which
simply draws back such packing picco when the steam pressure is
removed. It will thus be observed that an annular space U is provided
between the drum and the cylinder in which it revolves, and the steam
tightness of which annular space is secured by the application of the
dise plates or flanges H', whilst by the same means the friction agaiust
the ends of the cylinder is reduced to the minimum. Upon one side of
the interior of the cylinder a rectangular recess P is formed to receive a
corresponding shaped slide R of the same width as the annular space U,
and which slide is designed to advance across such annular space U
immediately the block K has passed the recess P, and so to form an
abutment for the steam, which exercises its pressure between such slide
and the block projecting from the periphery of the drum, and so com-
municates a revolving motion to the shaft G. The back of this slide R
is affixed to a hollow trunk S, which passes into a cylindrical slide box T,
where a piston S¹ and sleeve S² is mounted upon such hollow trunk, and
extends through the stuffing box S³, the sleeve portion S² of the piston
being designed to reduce the area of the back of the piston as compared
with the area at its front side, the steam space U at the back of the
piston being in communication with the steam chest V and steam supply
pipe V through the open passage W, and with the interior of the hollow
trunk S through the perforations X formed through the sleeve and
hollow trunk, which latter is further provided with ports Y leading into
the passages Z, opening into the interior of the annular space O when
the slide R is in contact with the periphery of the drum. The ports Y
are opened and closed by the small piston valve a, the spindle a¹
of which is extended through the stuffing box a², and is supported at its
outer extremity in the boss b projecting from the motion plate c secured
at the extremity of and moving with the hollow trunk S. The steam
spaced at the front of the piston S' is provided with two ports, tho
one marked e communicating with the exhaust pipe f, and the other
marked opening into the steam chest V, and being opened and closed
at suitable intervals by the slide valve h, as herein-after described.
I

page_text: The admission of steam to the cylinder is controlled as follows:-The
eccentric i upon the shaft G is connected by the eccentric rod j to an
arm & mounted upon tho rocking spindle working in the fixing m, and
which rocking spindle has at its other extremity a boss n from which
two arms project, the shorter one o being connected to and actuating
the valve spindle p, and the longer arm 7 having its slot r connected
to the extremity of the shorter arms of a double lever mounted upon a
stud t at the back of the motion plate c, the longer arm S' of such lover
being connected by a pin passing through a slot u formed in the motion
plate to a cam v mounted upon a stud upon the front side of such motion
plate. This cam serves to give the requisite motion to the piston
valvo a, the spindle a' of which is provided with a bowl w, which is
acted upon by the cam v, as hercin-after described. It should be here
remarked that the slot permits the motion plato c, cam v, piston
valve a, and double lever a to reciprocate with the hollow drum inde-
pendantly of the rocking spindle 2.
The action of this rotary engine is as follows:-The eccentric i is so
set upon the shaft G that the slide valve begins to open a communi-
cation between the space d at the front of the piston through tho
passage g, and the exhaust through the hollow of the slide valve him-
mediately that the block K has passed the slido R, when the pressure of
steam upon the back side of the piston S¹ causes the slide R to advanco
across the annular space O, and to rest in close and steam-tight contact
with the periphery of the drum H. The piston valve a meanwhile has
been forced open by the pressure of the steam in consequence of the 2
cam v permitting the bowl w upon the valvo spindle p to descend the
incline upon the câm v, and the full pressure of the steam is now
exerted through the passage Z between the slide R and the block K
upon the drum H, which latter is thus caused to revolve within the
annular space O until the return action of the eccentric has com- 3
monced, and first caused the bowl w upon the valve spindle a¹ to mount
the incline x on to the projecting part of the cam v, and so cut off tho
steam by drawing the piston valve a over the ports Y, leaving the steam
for the further part of the revolution of the drum to act expansively.
Now as the block K approaches the slide R the slide valve / opens a 3
communication between the steam chest V and the front side of the
pistou S', which being of larger area than the other side causes such
piston to recedo, and so withdraws the slide R from the annular space O,

page_text: and allows the block K to pass, this receding action of the piston con-
tinuing until it reaches and uncovers the exhaust port e, and so
establishes a balance of pressure on both sides of the piston, which is
thus brought to a stand still without a shock, the expanded or exhaust
steam from the annular space O escaping through the passage F¹³ into
the space F, and finally escaping through the exhaust pipe F³. The
eccentric has now again opened the communication between the
spaced and the exhaust, and the same operation is repeated, so main-
taining a continuous revolving motion of the drum.
In Fig. 3 is represented another modification of my Invention, in
which no hollow trunk and small piston valve is employed, but the
admission of steam is regulated entirely by a single slide valve. This
view also represents a method of applying my improvements so as to
reverse the motion of the drums, and so render such improvements
applicable to winding, locomotive, marine, and other engines which
require to reverse their direction. In this view the cylinder A is sur-
rounded by a similar space B for the exhaust steam as that described in
reference to Figs. 1 and 2, but the upper and lower parts of such space
are connected together by elbows, the mouths of which are seen and
marked B', and which exhaust space opens to the pipe C. The drum D
is similarly mounted upon a shaft E, leaving an annular space F sur-
rounding the periphery of the drum from which projects a block F¹. At
cach side of this cylinder a recess is formed fitted with a slide G, the
back of which is arranged with a solid piston H, which works in the
cylindrical slide box H', and has an enlarged rod I passing through the
stuffing box J. Only one of these slides G is in action at the same
time, the other slide being provided for running the engine in the
opposite direction. The front side of each of these piston H is also of
larger area than the back, and communicates through a port K with the
steam chest L; this steam chest is fitted with a slide valve M actuated
by the spindle N, which is connected to the arm o upon the rocking
spindle p, which in its turn is actuated by an eccentric upon the shaft E
in the same manner as the eccentric in the previous modification. The
steam pressure is exercised upon the back of the piston through the
passage Q, which is in communication with the steam chest L. Each of
the slides G has two passages formed through it, the one marked R for
the admission of steam through the port S, which is opened and closed
at suitable intervals by the slide valve M, and the other passage marked

page_text: T being arranged to form a communication with the exhaust when the
slide is in its position in the annular space, as seen in the left-hand slide
which is illustrated in this position.
The action of this modification is as follows:--If it be required to
run the engine in the direction of the arrows the left-hand slide must bo
withdrawn. When immediately the block F has passed the slide G the
slide valve M opens a communication between the front of the piston II
through the passage K, hollow of slide valve and port S, when the
pressure upon the back of the piston forces the slide G into contact with
the periphery of the drum D, by which time the slide valve M has
opened the port S to admit the steam which enters the annular space F
through the passage R in the slide G, and flows in until the slide
valve M cuts off the supply of steam, which then acts expansively in
the annular space until the slide valve M again opens the passage K,
and so admits steam to the front of the piston, which being of larger
area than the back causes the same to retire, and so withdraws the
slide G for the block F¹ to pass, when the same operation is repeated,
the exhaust steam meanwhile escaping through the passage T in the
slide G into the space B, whence it finds its way into the exhaust
pipe C. The steam supply pipes to the steam chests L are each provided :
in this modification with inlet valves, so as to be controlled by the
attendant who admits steam to either of the steam chests according
to the direction in which he wishes the shaft E to revolve, it being
understood that only one of the slides G is in operation at a time,
the other meanwhile remaining quiescent for the want of steam to
actuato it.
It will be readily apparent that a single cylinder and drum may be
employed for imparting revolving motion to a shaft in accordance with
either of the foregoing modifications of this Invention, in which case a
fly wheel would be required, but I prefer to uso two or more cylinders
and drums, and thus not only dispense with a fly wheel, but ensure the
full pressure of the steam being exercised upon the shaft during its
ontiro revolution.
In conclusion I would remark that rotary engines upon this principle
may also be driven by hot air, gas, explosive or otherwise, or by water
pressure, the valve arrangement being modified accordingly.
Having thus particularly described and ascertained the nature of this
my said Invention, together with the best methods with which I am

page_text: acquainted for carrying the same into practical effect, I wish it to be
understood that I do not confine myself to the precise details, relative
proportions or dimensions of the various parts of the engines illustrated
on the accompanying Drawings, and herein-before described, as the same
may be considerably varied without departing from the Invention; but
I wish it to be understood that I make no claim to a drum revolving in
an annular space, except as mounted in the peculiar manner herein-
before described, for the purposes of allowing expansion of the shaft, and
for keeping the drum steam-tight at the sides, and at the same time
reducing friction; and I claim particularly the method of actuating the
slide by the pressure of steam upon a piston, having by preferance a
larger area on one side than the other as and for the purposes described
and illustrated on the accompanying Drawings.
In witness whereof, I, the said William Eli Sudlow, have here-
unto set my hand and scal, this Twenty-second day of July, in
the year of our Lord One thousand cight hundred and seventy-
three.
Witness,
JOHN G. WILSON,
Patent Office,
71, Market Street,
Manchester.
WILLIAM ELI SUDLOW. (L.S.)