AN IMPROVED ROTARY STEAM ENGINE
Year: 1871

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine,
Lake, & Co., Patent Agents, Southampton Buildings, London, for
the Invention of "AN IMPROVED ROTARY STEAM ENGINE."-A com-
munication from abroad by Michael Schwartz, of Bangor, Maine,
United States of America.
COMPLETE SPECIFICATION filed by the said William Robert Lake at
the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 6th December 1871, pursuant to the 9th
Section of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME I, WILLIAM
ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London, send greeting.
WHEREAS I am in possession of an Invention for "AN IMPROVED
ROTARY STEAM ENGINE," and have petitioned Her Majesty to grant unto
me, my executors, administrators, and assigns, Her Royal Letters Patent

page_text: for the same, and have made solemn Declaration that it has been com-
municated to me from abroad by Michael Schwartz, of Bangor, Maine,
United States of America.
NOW KNOW YE, that I, the said William Robert Lake, do hereby
declare that the following Complete Specification, under my hand and
seal, fully describes and ascertains the nature of the said Invention, and
in what manner the same is to be performed, in and by the following
statement, reference being had to the accompanying Drawing forming
a part of this Specification :—
My Invention aims at producing an economical and effective rotary
engine which shall do its work without waste of steam and which will
be simple in construction and operation. The working parts of my
engine, such as the piston head and the cams operating the abutments
and regulating the admission of the steam, are all placed upon and
move with one central shaft. This arrangement ensures regularity and
certainty of oneration
DESCRIPTION OF THE DRAWING.
Figure 1 is a front elevation of my improved engine; Figure 2 is a
section of the cylinder and valves; Figure 3 is a side elevation of the
said enginc. Like letters indicate the same parts throughout the
Drawing.
At A is shewn the aforesaid central or main shaft having a collar B
working in the cylinder C of the engine, and making steam-tight joints
therewith by means of the packing rings c. The space between the
inner circumference of the cylinder C and the outer surface of the
collar B serves for the piston head D to work in. This piston head is
so attached to the collar that it and the shaft A revolve with the head
as the piston moves round. At E are levers pivotted to the standards F
below the shaft at their lower ends and attached at their upper ex-
tremities to rods G which pass into the cylinder C and are attached to
valves or abutments H, I. These arms or levers are operated by cams J
upon the main shaft and communicate their motion through the said
rods & to the abutments, which are set into the cylinder in such a way
as to close the space through which the piston D moves for a greater
part of its stroke, each valve H, I, closing half the space and meeting
in the centre. By the action of the cams J they are drawn apart, and
the space left clear for the passage of the piston when it arrives at that

page_text: part of the stroke and closed again when it has passed the same. They
thus act as abutments for the steam to act against. By a modification
of the cams J they may if desired be operated without the intervention
of the arms E. At L is the exhaust of the engine, which remains
5 always open, the piston forcing the steam through the same as it
advances. At is shewn a smaller pipe placed close to the abut-
ments H, I, and connecting with the exhaust. This relieves the engine
of the compressed air, which would otherwise accumulate between the
piston and the abutments after the former had passed the exhaust. Steam
is admitted to the cylinder through the feed pipe M, and the supply is
regulated by the valve N operated by rods d, levers e, f, rod g, and a
cam o upon the shaft A. This cam may be arranged to cut off the
steam at any desired point, allowing the piston to be operated expansively
during the remainder of the stroke. After the steam passes the valve N
it enters the cylinder C through ports in the abutments II, I, forcing
itself directly against the piston. The abutments are halved together
and overlap each other at the point of contact so that the pressure of
the steam against them tends to make the joints tight.
The operation of this improved engine is as follows:-Suppose the
piston to be at P, Figure 3, the abutments H, I, being closed and
steam being admitted through the feed pipe it forces the piston forward
driving the air before it through the exhaust pipe. If the cut off
valve N is arranged to check the steam at half stroke, the expansion
drives the piston forward and past the exhaust L, the air between the
said exhaust and the abutments being expelled through the pipe 7.
As the head nears the abutments the cams J acting upon the arms E, E,
opens them, allowing the piston to pass, and closes them behind it,
steam is admitted again by the action of the cam O, and the operation
is repeated. A short lever is attached to the rods operating the cut-
off valve so that steam may be admitted with case when it is desired to
start the engine.
To render the action of the engine reversible the ports p, q, in tho
abutments H, I, may be made upon opposite sides of the said abutments
Figure 2, and steam may be admitted to the cylinder through either of
them and the passages k, m, by a valve j, opening one of the said
passages and closing the other simultaneously. The cam o is made
double and the arm 9 so arranged as to be adjusted at will from one
side to the other as from o to o', thus cutting off the steam at the
proper place in the stroke no matter in which direction the piston may

page_text: be travelling. Two exhaust pipes are also provided and furnished with
valves, the one nearest the port through which the steam enters being
the one to be closed during the action of the engine.
Having thus fully described the said Invention as communicated to
me by my foreign correspondent, and shewn how the same may be
conveniently and advantageously carried into practice I claim,-
First. The combination of the cams J and cam o, with the collar B,
and piston D revolving in the cylinder C, and arranged upon a central
shaft A, as herein set forth.
Second. The combination of the cams J and arms E with the rods G
and abutments H, I, as herein set forth.
Third. The combination of the valve N, rods d, levers e, f, rod g, and
double cam o, o¹, as herein set forth.
Fourth. The combination of the valvo j, passages k and m,
ports p and q in the abutments H, I, as herein set forth.
and
Fifth. The combination of the piston D, abutments H, J, having
ports p, q, therein, exhaust L, and escape l, as herein set forth.
In witness whereof, I, the said William Robert Lake, have here-
unto set my hand and seal, this Sixth day of December, in the
year of our Lord One thousand eight hundred and seventy-
one.
Witness,
E. C. JACKSON.
W. ROBT. LAKE. (L.S.)