IMPROVEMENTS IN ROTATORY ENGINES
Year: 1873

page_text: LETTERS PATENT to Joseph Stead, of Ashton-under-Lync, in the
County of Lancaster, for the Invention of "IMPROVEMENTS IN ROTATORY
ENGINES."
Scaled the 18th July 1873, and dated the 22nd January 1873.
PROVISIONAL SPECIFICATION left by the said Joseph Stead at the
Office of the Commissioners of Patents, with his Petition, on the
22nd January 1873.
I, JOSEPH STEAD, of Ashton-under-Lync, in the County of Lancaster,
do hereby declare the nature of the said Invention for "INPROVEMENTS
IN ROTATORY ENGINES," to be as follows:-
My Invention relates to the class of prime movers well known as
rotatory engines. In such an engino constructed in manner according
with my Invention two or more pistons or leaves or vancs acting as
pistons are fitted to revolve within a cylinder around an axis which is
concentric with the interior of the said cylinder. The said pistons are
mounted upon a shaft or are connected with a shaft or with shafts, to
which a revolving motion is to be imparted. Each of the said pistons
is connected with the said shaft or with one of the said shafts by means
of a ratchet wheel and pawl or pawls, or of a friction or other suitable
clutch, the arrangement being such as that the said piston when rotating
gives motion to the said shaft at the same time that the shaft is at

page_text: liberty to continue to revolve, although the said piston may be at rest.
A similar arrangement is employed to prevent each piston from revolving
in any but one direction, that is to say, the direction of revolution of
the said shaft. The aforesaid cylinder is provided with inlet and exhaust
ports for steam or other propelling fluid. The action of the engine is
somewhat as follows, namely:-Supposing two pistons to be employed,
and the said pistons to be close together, one piston being situated
between the aforesaid ports, and that steam is admitted through the said
inlet port, the said steam will flow between the two pistons and will
force the forward piston around until it nears or touches the other piston
which has remained stationary. Both pistons will now move together
until they have changed places, when the piston which remained
stationary as aforesaid will now be caused to revolve, the other piston
remaining stationary. These alternate revolutions of the two pistons
being repeated a continuous revolving motion is imparted to the aforesaid
shaft or shafts.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Joseph Stead in the Great Seal Patent Office on
the 22nd July 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOSEPU
STEAD, of Ashton-under-Lync, in the County of Lancaster, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second 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 grant unto me, the said Joseph Stead, Her special license that
I, the said Joseph Stead, my executors, administrators, and assigns, or
such others as I, the said Joseph Stead, my executors, administrators,
and assigns, should at any timo 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 Ircland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN ROTATORY
ENGINES," upon the condition, amongst others, that I, tho said Joseph

page_text: Stead, 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 Joseph Stead, 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 and accompanying Drawings, that is to
say :-
My Invention relates to the class of prime movers well known as
rotatory engines. In such an engine constructed in manner according
with my Invention two or more pistons or leaves or vanes acting as
pistons are fitted to revolve within a cylinder around an axis which is
concentric with the interior of the said cylinder. The said pistons aro
mounted upon a shaft or are connected with a shaft or with shafts, to
which a revolving motion is to be imparted. Each of the said pistons
is connected with the said shaft or with one of the said shafts by means
of a ratchet wheel and pawl or pawls, or of a friction or other suitable
clutch, the arrangement being such as that the said piston when rotating
gives motion to the said shaft at the same time that the shaft is at
liberty to continue to revolve, although the said piston may be at rest.
A similar arrangement is employed to prevent each piston from revolving
in any but one direction, that is to say, the direction of revolution of
the said shaft. The aforesaid cylinder is provided with inlet and exhaust
ports for steam or other propelling fluid. The action of the engine is
somewhat as follows, namely:-Supposing two pistons to be employed,
and the said piston to be close together, one piston being situated
between the aforesaid ports, and that steam is admitted through the said
inlet port, the said steam will flow between the two pistons and will
force the forward piston around until it nears or touches the other piston
which has remained stationary. Both pistons will now move together
until they have changed places, when the piston which remained
stationary as aforesaid will now be caused to revolve, the other piston
remaining stationary. These alternate revolutions of the two pistons
being repeated a continuous revolving motion is imparted to the aforesaid
shaft or shafts.

page_text: And in order that my said Invention may be fully understood I will
now refer to the accompanying Drawings mado about onc-eighth of the
full size and marked with letters of reference, corresponding marks
indicating the same parts in the various Figures. In the said Drawings
Figs. 1, 2, and 3 represent vertical sections of a rotatory engine con- ¦
structed in accordance with my said Invention, and Fig. 4 is a vertical
section on the axial line of the said engine, sections 1 and 2 being taken
on the line A, and section 3 on the line B, in Fig. 4.
In the said Figs. a is a cylinder, which is truly bored and provided
with and covers b, b, and tho said end covers are formed with " stuffing
boxes," in which the central shaft c is fitted to revolve. The central
part of the said shaft is formed with ratchet teeth, as seen in Figs. 1 to 3,
and is embraced by the bosses of the two pistons d, d, one of which is
shewn detached at Figs. 5 and 6.
The bosses of the said two pistons
are situated end to end, and occupy the central part of the cylinder from
cover to cover, and each piston projects over the boss of the other piston
so as also to extend from cover to cover. The edges of the piston
marked e, e, in Fig. 5, are provided with metallic packing, which bears
against the said end covers, and the edge ƒ and g are also provided with
packing, which bears in the one case against the inner circumference of
the cylinder, and in the other caso against the periphery of the boss of
the other piston, the said packings being shown at i, i, in the Drawings.
Pawls k, k, are mounted in recesses formed in each of the said bosses,
and aro provided with springs which maintain the said pawls in gear
with the ratchet teeth formed on the central shaft, the said recesses
being covered by means of a cylindrical turned ring 1, which is secured
on the boss and constitutes the surface upon which the packing at g in
the other piston works. The cylinder is formed with an inlet port me
for steam and with an outlet or exhaust port n, and in openings formed
on each side of the said exhaust port are fitted sliding catclics o, o, which
aro seen in Fig. 3 and in Fig. 7, which last represents a section taken
through the said catches and exhaust port.
The action of the engine may be described as follows:-When the
two pistons are in the positions represented in Fig. 1 steam will be
flowing into the cylinder, and the piston marked 1 will be moving in
the direction of the arrow and be turning the central shaft by means of
the pawls k, k, the piston 2 being prevented by the catches o, o, from
moving backwards. When the piston 1 has arrived in the position scen

page_text: in Fig. 2 it will come into contact with piston 2, and both pistons will
move together into the positions seen in Fig. 3, when the catches o, o,
which have been raised by the passing piston will fall behind piston 1
and will prevent any return movement of the said piston. The entering
steam will now have admission between the two pistons, and piston 2
will be forced around and will continue the movement of the central
shaft, the pawls of piston 1 slipping over the aforesaid ratchet teeth,
and the alternate movements of the two pistons will impart a continuous
revolving motion to the said shaft. Although when describing the
Drawings I have referred only to an engine actuated by steam, water
engines, or prime movers, actuated by water or other fluid, may be con-
structed on the same principle.
Having now fully described the nature of my said Invention and
means whereby I may carry the same into practical effect, I would in
conclusion have it to be distinctly understood that I do not confine
myself to the precise details of the apparatus herein described and illus-
trated in the accompanying Drawings, but that what I consider to be
my Invention is the employment of two or more pistons, each of which
at times imparts motion to the central shaft, and at other times acts as a
stationary abutment, substantially in the manner herein-before set forth
and indicated.
In witness whereof, I, the said Joseph Stead, have hereunto set
and and acol this hunter first dow of Tul in the your of
Signed and scaled by the said Josephi Stead,
in the presence of
EDWARD K. DUTTON,
Agent for the Patentec,
Manchester.
JOSEPH STEAD. (L.S.)