IMPROVEMENTS IN ROTARY ENGINES
Year: 1864

page_text: LETTERS PATENT to James Empson, of Hamburgb, Iron Ship Builder,
and Heinrich Von Hartz, of the same Place, Engineer, for the Inven-
tion of "IMPROVEMENTS IN ROTARY ENGINES."
Sealed the 8th September 1864, and dated the 15th March 1864.
PROVISIONAL SPECIFICATION left by the said James Empson and
Heinrich Von Hartz at the Office of the Commissioners of Patents,
with their Petition, on the 15th March 1864.
We, JAMES EMPSON, of Hamburgh, Iron Ship Builder, and HEINRICH
VON HARTZ, of the same Place, Engineer, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN ROTARY ENGINES," to be, as.
follows:-
The cylinder is made in two halves, each of which is turned inside to a
template, so as to be exact counterparts of each other, and then the two-
halves are fixed together with accuracy. In the interior of the cylinder there.
is a circular plate or collar acting as a crank, and forming part of a central
boss, which is fitted conically into glands connected to both sides of the
cylinder, and maintained at a uniform pressure by springs. The crank or
-

page_text: collar extends to the piston part of the cylinder, and works between two rings
provided with springs. The piston is fixed to the crank or collar, and works
in a bore at the outer circumference of the cylinder. The crank has an oblong
hole, into which is loosely fitted the main shaft of the engine, so that there
shall be no friction on the crank or glands. In the piston part of the
cylinder there is a space to which is fitted a slide, one side of which works
close to the rings at the side of the collar or crank. The slide is enclosed in
a box or case having a stuffing box, and to the outer end of the slide rod is
connected a roller, which is placed in an elliptic or cam groove, in a drum
fixed to the main shaft, so that as the drum revolves. the. slide shall move out
to allow the traverse of the piston and then close up quickly.. When there
is a double engine having two cylinders, the grooved drum is placed between,
and the grooves arranged accordingly. For regulating the supply and exhaust
of the cylinder there is a slide valve worked by a loose eccentric on the main
shaft, there being stops for working the engine forwards or backwards, and
air pumps, feed pumps, and other apparatus can be worked by eccentrics on the
main shaft or otherwise.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Empson and Heinrich Von Hartz in the Great Seal
Patent Office on the 14th September 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JAMES
EMPSON, of Hamburgh, Iron Ship Builder, and HEINRICH VON HARTZ, of the
same Place, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifteenth day of March, in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-seventh year of
Her reign, did, for Herself, Her heirs and successors, give and grant, unto
us, the said James Empson and Heinrich Von Hartz, Her special licence
that we, the said James Empson and Heinrich Von Hartz, our executors,
administrators, and assigns, or such other's as we, the said James Empson
and Heinrich Von Hartz, our 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 vend, within. the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention

page_text: for "IMPROVEMENTS IN ROTARY ENGINES," upon the condition (amongst
others) that we, the said James Empson and Heinrich Von Hartz, our
executors or administrators, by an instrument in writing under our, or
their, or oue of their hands and seals, should particularly describe and
5 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 we, the said James Empson and Heinrich Von
Hartz, do hereby declare the nature of our said Invention, and in what
manner the same is to be performed, to be particularly described and
ascertained in and by the following statement (that is to say):- 7
The cylinder is made in two halves, each of which is turned inside to a
template, so as to be exact counterparts of each other, and then the two
halves are fixed together with accuracy. In the interior of the cylinder there
is a central plate or disc acting as an arm, and forming a central boss, which
is fitted conically into glands connected to both sides of the cylinder. The
arm extends to the piston part of the cylinder, and works between two rings
provided with springs. The piston is fixed to the arm and works in a
circular space or bore at the outer circumference of the cylinder. The boss
of the arm has an oblong hole, into which is loosely fitted the main shaft of the
engine, so that there shall be no friction on the arm and glands. In the bore
of the cylinder in which the piston works there is a space to which is fitted
a stop slide, one side of which works close to the rings at the side of the arm.
The slide is enclosed in a box or case having a stuffing box, and to the outer
end of the slide rod is connected a roller, which is placed in an elliptic or cam
groove cut or formed in a drum fixed to the main shaft, so that as the drum
revolves the slide shall move out to allow the traverse of the piston, and then
close up quickly. When there is a double engine having two cylinders, the
grooved drum is placed between, and the grooves arranged accordingly. For
regulating the supply and exhaust of the cylinder there is a slide valve
worked by a loose eccentric on the main shaft, there being stops for working
the engine forwards or backwards, and air pumps, feed pumps, and other
apparatus can be worked by eccentrics on the main shaft or otherwise.
This Invention will be clearly understood by referring to the figures and
letters on the accompanying two Sheets of Drawings, in which Fig. 1 is a side
elevation of one of our improved double rotary engines; Fig. 2, an end
elevation of one of the pistons and arms; Fig. 8, a section of one of the

page_text: cylinders, stop slide, and main shaft, with the piston and arm in elevation;
Fig. 4, a view of one of the eccentrics and slide motion; Fig. 5, Sheet 2, a
cross section of one of the cylinders and parts connected with it drawn to an
enlarged scale; and Fig. 6, Sheet 1, a Diagram representing the working
properties of a rotary engine.
a, b, represent the two halves of the cylinder; c, the piston; d, the bore or
space in which it works; e, the arm to which the piston is connected; f, the
ss of the arm; g, the conical glands for keeping the boss tight; h, the
rings and springs for preventing the escape of steam to the arm; i, the main
sbaft; k, the stop slide; 2, the box for the slide; m, Fig. 1, the grooved drum
for working the stop slides of the two cylinders; n, Fig. 4, one of the slide
valves for admitting and exhausting the steam; o, the eccentrics for working
the slide valves; p, one of the valve rods; g, the steam and exhaust passages;
and r, the starting, stopping, and reversing gear, each of the passages q being
either for steam or exhaust, according to the direction in which the piston and
shaft are turned. The two halves of each cylinder are bolted together by
the bolts s, Fig. 1, the bore or space for the piston being made of a circular
form, across which space the stop slide works square through and down to the
rings h, so as to cut off the steam, and is tight in itself. For giving motion
to the stop slides each slide rod has connected to it an antifriction roller t,
which works in grooves cut or formed in the drum m, so that as the drum
revolves, the slides move out to allow the pistons to pass, and then move
quickly in to form a resisting surface to the steam. In the boss f, there is an
oblong hole, to which an oblong part of the main shaft is fitted for the
purpose of turning the shaft, but at the same time preventing friction. In
Fig. 6, Sheet 1, we represent the working properties of the rotary engine; d
represents the diameter of the cylinder bore or space, and s, s, the stop slide
which separates the exhaust port from the steam port. If the piston & be in
position, and the steam port quite open, then the piston works full power to
position, meanwhile the exhaust port is open, and the resisting pressure in the
cylinder is one atmosphere; now the steam begins to expand, and is cut off
from the cylinder by the slide valve, and the piston works by expansion from
position to position. During three-quarters of the stroke the slide s, s, is
shut and the steam exhausts before the piston through the outlet port. Now
the slides, s, moves back from the cylinder d, from position into its box,
meanwhile both ports are open to the exhaust, the pressure in cylinder equal,
and the engine would come to a stand-still, but the piston in the other cylinder
is working full power, during this quarter of a stroke dead, and the velocity of

page_text: the loose main shaft, and the: general arrangement of the machine as
herein described and illustrated in the accompanying two Sheets of Drawings..
In witness whereof, we, the said James Empson, and Heinrich Von
Hartz, have hereunto set our hands and seals, this Eighth day of
September, in the year of our Lord One thousand eight hundred and
sixty-four.