IM- PROVEMENTS IN ROTARY ENGINES
Year: 1867

page_text: LETTERS PATENT to William Clark, of 53, Chancery Lane, in the, County
of Middlesex, Engineer and Patent Agent, for the Invention of "IM-
PROVEMENTS IN ROTARY ENGINES."-A communication from abroad by
Truman Merriam and James Cushing, both of Waterlos, Jefferson
County State of Wisconsin. United States of America..
Sealed the 5th April 1867, and dated the 14th January 1867.
PROVISIONAL SPECIFICATION left by the said William Clark at the
Office of the Commissioners of Patents, with his Petition, on the
14th January 1867.
I, WILLIAM CLARK, of 53, Chancery Lane, in the County of Middlesex,
Engineer and Patent Agent, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN ROTARY ENGINES," to be as follows:-
This Invention consists, first, in the arrangement of a series of cylinders
and pistons upon a revolving drum mounted on a shaft in combination with
a face plate and ports and adapted to segmental apertures in a stationary
steam chest in such a manner that a constant pressure of steam may be
alternately applied to the piston, whereby the leverage and power of the engine
will be increased without a corresponding increase in the consumption of
steam.
.It consists, secondly, in the arrangement of one or more curved tracks in
combination with a common cross head provided with trucks or pins, and with
Price 8d.1

page_text: a common reciprocating piston fitted in a cylinder, which is secured to a
revolving drum in such a manner that the reciprocating motion of the piston
is converted in a revolving motion of the drum and cylinder, whereby a rotary
engine of considerable power is obtained.
It consists, thirdly, in the arrangement of a steam chest with an oscillating
joint in combination with the face plate of the cylinders, or of the drum
containing said cylinders in such a manner that said steam chest can be reversed
one quarter, and the motion of the engine thereby reversed.
This Invention is illustrated in the accompanying Drawing, in which
Figure 1 represents an inside elevation of the steam chest; Figure 2 is a
vertical central section of the same; Figure 3 is a detached perspective view
of the disc supporting the supply and exhaust pipes; Figure 4 is a side
elevation of the engine. Similar letters of reference indicate corresponding
parts.
A represents the steam chest which is divided in two concentric compart-
ments B, C, as clearly shown in Figure 1. The inner compartment B is the
steam supply chamber, and the outer compartment C is the exhaust chamber,
steam being supplied through a pipe B' and exhausted through a pipe C¹(see
Figure 3). The steam chamber B communicates by suitable channels with
the segmental slots a, b, through which the steam is admitted to the several
cylinders, as will be presently explained. The pipes B', C, are secured in a
disc D, which is fitted into a recess on the outside of the steam chest cover,
and it is held in position by a plate which is provided with segmental slots to
admit the pipes B, C. The slots are of such a length that a quarter revo-
lution can be imparted to the steam chest for the purpose of reversing the
engine. Said steam chest is fitted on the face of the drum F, which is bored
out to form a series of radiating cylinders G,shown in dotted lines in Figure 4,
and it is provided with two sets of ports e, f, one set to correspond to the
segmental slots a in the steam chest, and to admit steam to the outer ends of
the several cylinders, and one set to correspond to the segmental slots in the
steam: chest, and to admit steam to the outer ends of the several cylinders, and
one set to correspond to the segmental slots b in the steam chest, and to admit
steam to the inner ends of the cylinders. Each of the slots a covers one
quarter of the ports f, and each of the slots bone quarter of the ports e, and
by referring to Figure 1 it will be noticed that the slots a are opposite the
open spaces between the slots b, and the slots opposite the open spaces
between the slots a, so that those cylinders which take steam through the
outer ports are free to exhaust through the corresponding inner ports, and
vice versa.
From this description it will be readily understood how by

page_text: Where
turning the steam chest one-quarter revolution, the motion of the engine is
reversed. The cylinders Gare provided with pistons of any suitableconstruction,
and the piston rods H which extend through the outer heads of the cylinders
connect with cross heads; these cross heads are provided with friction rollers
which work between the rectilinear guides J, and they are also furnished with
double or single trucks K, single trucks being shown in Figure 4.
single trucks are used, as in Figure 4, double sets of tracks L have to be
applied, one set inside and one outside the wheels which compose the trucks,
and said trucks are made in the form of ellipses, or in any other suitable
form or shape, so that when steam is admitted to the cylinders and the
various trucks are forced against the tracks in or out, as the case may be, by
the action of the truck wheels against the tracks a revolving motion is
imparted to the drum F. If the double trucks are used the tracks L are
placed between them, and in cases where it is desirable to run the engine at
a very high speed the trucks are dispensed with altogether, and the cross heads
are provided with studs which catch in grooves in the tracks. By these
means a rotary steam engine is obtained, the cylinders of which take steam
and exhaust the same twice during each revolution of the drum, and the
pistons reciprocate comparatively slow in their cylinders, so that the steam
acts on them with the full boiler prsssure, or nearly so, even when the engine
makes three hundred revolutious per minute.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Clark in the Great Seal Patent Office on the
1st July 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
CLARK, of 53, Chancery Lane, in the County of Middlesex, Engineer and
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of January, in the year of our
Lord One thousand eight hundred and sixty-seven,in'the thirtieth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said William Clark, Her special licence that I, the said William Clark, my
executors, administrators, and assigns, or such others as I, the said William
Clark, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise, and

page_text: vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN ROTARY
ENGINES," a communication to ine from abroad by Truman Merriam and James
Cushing, both of Waterloo, Jefferson County, State of Wisconsin, United States
of America, upon the condition (amongst others) that I, the said William
Clark, my executors or administrators, by an instrument in writing under
my, or their, or one of their hands and seals, 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 Clark, 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 follow-
ing statement, reference being had to the 2 Sheets of Drawings hereunto
annexed, and to the letters and figures marked thereon (that is to say):-
This Invention consists, first, in the arrangement of a series of cylinders and
pistons upon a revolving drum mounted on a shaft in combination with a face
plate and ports,and adapted to segmental apertures in a stationarysteam chest
in such a manner that a constant pressure of steam may be alternately applied
to the piston, thereby increasing the leverage and power of the engine without
a corresponding increase in the consumption of steam.
It consists, secondly, in the arrangement of one or more curved tracks in
combination with a common cross head provided with trucks or pins, and with
a common reciprocating piston fitted in a cylinder,. which is secured to a
revolving drum in such a manner that the reciprocating motion of the piston
is converted in a revolving motion of the drum and cylinder, and a rotary
engine of considerable power is attained.
It consists, thirdly, in the arrangement of a steam chest with an oscillating
joint in combination with the face plate of the cylinders or of the drum cou-
taining said cylinders in such a manner that said steam chest can be reversed
one quarter, and thereby the motion of the engine is reversed.
This Invention is illustrated in the accompanying Drawing, in which Figurel
represents an inside elevation of the steam chest; Figure 2 is a vertical central
section of the same; Figure 3 is a detached perspective view of the disc
supporting the supply and exhaust pipes; Figure 4 is an outside view of the
steam chest cover; Figure 5 is a detached elevation of the slotted plate which
keeps the disc, Figure 3, in its place; Figure 6 is a side elevation of the
engine when the steam chest and the curved tracks are removed; Figure 7

page_text: is a similar elevation to the previous Figure, looking at the Engine from the
opposite side; Figure 8 is a partial side elevation of a modification thereof;
Figure 9 is a perspective view of the same; Figure 10 is a detached view of
one of the cross heads. Similar letters of reference indicate corresponding
parts.
A represents the steam chest, which is divided in two concentric compart-
ments B, C, as clearly shown in Figure 1; the inner compartment B is the
steam supply chamber, and the outer compartment C is the exhaust chamber,
steain being supplied through a pipe B', and exhausted through a pipe C³ (see
Figure 3). The steam chamber B communicates by suitable channels with
the segmental slots a, b, through which the steam is admitted to the several
cylinders, as will be presently explained; the pipes B', C¹, are secured in a
disc D, which is fitted into a recess c on the outside of the steam chest cover
(Figure 4), and it is held in position by a plate E, which is provided
with segmental slots d to admit the pipes B', C¹. The slots are of such
a length that a quarter revolution can be imparted to the steam chest for the
purpose of reversing the engine. Said steam chest is fitted on the face of
the drum F which is bored out to form a series of radiating cylinders G, shown
in dotted lines in Figures 7 and 5, and it is provided with two sets of ports e,f,
one set to correspond to the segmental slots a in the steam chest and to admit
steam to the outer ends of the several cylinders, and one set to correspond to
the segmental slots b in the steam chest and to admit steam to the inner ends
of the cylinders. Each of the slots a covers one quarter of the ports f, and
each of the slots bone quarter of the ports e, and by referring to Figure 1 it
will be noticed that the slots a are opposite the open spaces between the
slots b, and the slots opposite the open spaces between the slots a, so that
those cylinders which take steam through the outer ports are free to exhaust
through the corresponding inner ports, and vice versa. From this description
it will be readily understood how by turning the steam chest one quarter
revolution the motion of the engine is reversed. The cylinders G are provided
with pistons of any suitable construction, and the piston rods H which extend
through the outer heads of the cylinders connect with cross heads I, a detached
view of one of which is shown in Figure 10; these cross heads are provided
with friction rollers i which work between the rectilinear guides J, and they
are also furnished with double or single trucks K,double trucks being shown
in Figures 8 and 9, and single trucks in Figures 6 and 7.
Where single
trucks are used, as in Figures 6 and 7, double sets of tracks L have to be
applied, one set inside and one outside, the wheels which compose the trucks
and said tracks are made in the form of ellipses, or in any other suitable form

page_text: or shape, so that when steam is admitted to the cylinders and the various
trucks are forced against the tracks in or out, as the case may be, by the
action of the truck wheels against the tracks a revolving motion is imparted
to the drum F. If the double trucks are used the trucks Lare placed between
them, as shown in Figures 8 and 9, and in cases where it is desirable to run
the engine at a very high speed the trucks are dispensed with altogether and
the cross heads are provided with studs (see Figure 10) which catch i
grooves in the tracks, said grooves being shown in Figure S. By these
means a rotary steam engine is obtained, the cylinders of which take steam
and exhaust the same twice during each revolution of the drum, and the
pistons reciprocate comparatively slow in their cylinders, so that the steam
acts on them with the full boiler pressure or nearly so, even when the engine
makes three hundred revolutions per minute.
Having described the nature of this Invention, and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the
herein-before in part recited Letters Patent is, ―
First, the arrangement of a series of cylinders and pistons upon a revolving
drum mounted on a shaft in combination with a face plate and ports, and
adapted to segmental apertures in a stationary steam chest, substantially as
and for the purpose described.
Secondly, the arrangement of one or more curved tracks in combination
with a common cross head provided with trucks or pins and with a common
reciprocating piston fitted in a cylinder which is secured to a revolving drum,
substantially as and for the purpose set forth.
Thirdly, the arrangement of a steam chest with an oscillating joint in con-
bination with the face plate of the cylinders or of the drum containing said
cylinders, substantially as and for the purpose described.
In witness whereof, I, the said William Clark, have hereunto set my
hand and seal, this Twenty-fourth day of June, in the year of our Lord
One thousand eight hundred and sixty-seven.
W. CLARK. (L.S.)