IMPROVEMENTS IN ROTATORY ENGINES
Year: 1874

page_text: LETTERS PATENT to William Barnard Pinhey, of Bennett Park,
Blackheath, in the County of Kent, Surveyor, for the Invention of
"IMPROVEMENTS IN ROTATORY ENGINES."
Şealed the 19th March 1875, and dated the 24th September 1874.
PROVISIONAL SPECIFICATION left by the said William Barnard Pinhey
L
at the Office of the Commissioners of Patents, with his Petition,
on the 24th September 1874.
I, WILLIAM BARNARD PINHEY, of Bennett Park, Blackheath, in
the County of Kent, Surveyor, do hereby declare the nature of tho
said Invention for "IMPROVEMENTS IN ROTATORY ENGINES," to be as
follows:-
My Invention relates to the class of prime motors well known as
rotatory engines; such an engine constructed in manner according
with my Invention consists of a drum upon a shaft revolving in a
suitable casing (through stuffing boxes or bearings) of larger internal
diameter than the drum so as to afford an annular space around the
periphery of such drum; in this space two pistons or leaves are so fitted

page_text: as to perform a semi-revolution on their own axis (a sinking or recess
being formed in the periphery of the drum, and also in the circum-
ference of the annular casing) to allow of one piston passing the other,
when they are retained in a radial position during the remainder of the
revolution of the drum, thus dividing the annular space into two
compartments, in one of which the steam pressure is admitted by means
of ports & slide worked in the usual manner, and the other compart-
ment is open to the atmosphere, or is in communication with an air
pump and condenser.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Barnard Pinhey in the Great Seal Patent
Office on the 23rd March 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
BARNARD PINHEY, of Bennett Park, Blackheath, in the County of Kent,
Surveyor, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fourth day of September, in the
year of our Lord One thousand eight hundred and seventy-four, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said William Barnard Pinhey, Her
special licence that I, the said William Barnard Pinhey, my executors,
administrators, and assigns, or such others as I, the said William Barnard
Pinhey, 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 vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN ROTATORY ENGINES," upon the condition (amongst
others) that I, the said William Barnard Pinhey, my executors
or administrators, by an instrument in writing under my, or their,
or one of their hands and seals, should particularly describe and

page_text: 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 Barnard Pinhey, 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:
My Invention relates to the class of prime motors well known as
rotatory engines; such an engine constructed in manner according
with my Invention consists of a drum upon a shaft revolving in a
suitable casing (through stuffing boxes or bearings) of larger internal
diameter than the drum so as to afford an annular space around the
periphery of such drum; in this space two pistons or leaves are so fitted
as to perform a semi-revolution on their own axis (a sinking or recess
being formed in the periphery of the drum, and also in the circum-
ference of the annular casing) to allow of one piston passing the other,
when they are retained in a radial position during the remainder of the
revolution of the drum, thus dividing the annular space into two
compartments, in one of which the steam pressure is admitted by means
of ports and slide worked in the usual manner, and the other compart-
ment is open to the atmosphere, or is in communication with an air
pump and condenser.
By a suitable arrangement for reversing the motion the induct
passage in the annular casing then becomes the exhaust, and vice
versa.
And in order that this my said Invention may be fully understood,
I have hereunto annexed a Sheet of Drawings illustrative of my im-
provements, and marked with letters and figures of reference, corre-
sponding 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 constructed in accordance with my said Invention ;
Fig. 4 is a vertical section on the axial line of the said engine, section,
Fig. 1, being taken on the line A, section, Fig. 2, on the line B, and
section, Fig. 3, on the line C in Fig. 4; Fig. 5 is part section shewing
piston 2 on the line D, Fig. 1.

page_text: In the said Figures, a is a cylinder which is truly bored, having a
recess formed therein to allow of piston 1 revolving on its axis; and
such cylinder is enclosed at each end by the cover plates band b¹
secured with set screws, and the said cover plates are formed with
bearings in which the central shaft c is fitted to revolve, and upon
which central shaft the flanged drum d is keyed, the periphery of such
drum being formed with a recess to allow of piston 2 revolving on its
axis. Piston 1 revolves on axis e in bearings fitted to cover plates;
such piston has a catch plate ƒ affixed to axis, a chamber being formed
in cover plate 6 for such catch plate. Piston 2 revolves on axis -g-in
bearings fitted to flanges of drum d, and has catch plate h affixed to
axis, a sinking being formed in flange to take such plate on the drum
performing a revolution. The catch plate ƒ engages in the stud i affixed
to the flange of drum; and the catch plate / engages in the stud j
affixed to cover plate 6', which cause the pistons to make a semi.
revolution on their own axis, during which piston 2 passes piston 1,
and after which each piston is retained in a radial position until the
catch plates again engage in the studs, as shewn by Figs. 2 and 3. In
Fig. 2 the catch plate / affixed to piston 2 runs in the groove / formed
in the cover plate 6 until engaging in the stud j, around which stud
the groove is sunk to allow the plate to revolve. In Fig. 3 the catch
plate affixed to piston 1 is retained in position by the rebate n in the
flange of drum until engaging in stud i, around which stud the rcbate
or sinking is enlarged to allow of the plate f revolving. The steam
tightness of the joints O between the flanges of drum and the cover
plates is secured by metallic packing, as also the joints around edges of
pistons..
In Fig. 1 the pistons are shown in the positions they occupy on
the admission of steam, which enters from steam chamber p, through
the disct at the port », and escapes, after acting on piston 2 (causing the
drum and shaft to revolve) at s through the exhaust passage u, Fig. 4;
being the slide valve worked by the usual eccentric w.
Figs. 6, 7, and 8 show the arrangement for reversing the motion of
the engine; Fig. 6 is a horizontal section of disc t, and Fig. 7, a vertical
section on line E, Fig. 6, of disc; Fig. 8 is a horizontal section of steam
chamber p, Fig. 1, with slide valve removed, shewing ports and s, the
aperture 4, Fig. 6, being opposite 2, Fig. 8, allows the steam to pass
through port as shewn in Fig. 1; the exhaust steam on emerging

page_text: through s, Fig. 1, is conducted by the recess 3, Figs. 6 and 7, to the
exhaust passage u; upon turning the disc quarter round by means of
the lever x, Fig. 1, the aperture 5, Fig. 6, will be opposite the port 8,
which will then admit the steam, the port forming the exhaust, and
thus reversing the motion.
In engines of certain proportions the studs upon which the catch
plates engage may be formed on and be part of axis of pistons. To
facilitate fixing catch plates to pistons suitable apertures may be formed
in cover plates.
Although when describing the Drawings I have referred only to an
engine actuated by steam, water engines or prime movers actuated by
water, air, or gas may be constructed 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 which I consider to be
my Invention is, the employment of two revolving pistons, one of which
pistons imparts motion to the central shaft and drum, and the other
acts as a stationary abutment, substantially in the manner set forth and
indicated.
In witness whereof, I, the said William Barnard Pinhey, have here-
unto set my hand and seal, this Twenty-third day of March, in
the year of our Lord One thousand eight hundred and seventy-five.
WILLIAM BARNARD PINHEY. (L.S.)