IMPROVEMENTS IN ROTATORY ENGINES
Year: 1862

page_text: LETTERS PATENT to Andrew Blair, of the Dawsholm Print Works, in tho
County of Dumbarton, North Britain, Calico Printer, for the Invention
of "Az DomimDE TH
"
PROVISIONAL SPECIFICATION left by the said Andrew Blair at the Office
of the Commissioners of Patents, with his Petition, on the 8th March
1862.
I, ANDREW BLAIR, of the Dawsholm Print Works, in the County of
Dumbarton, North Britain, Calico Printer, do hereby declare the nature of
the said Invention of "IMPROVEMENTS IN ROTATORY ENGINES," to be as follows,
that is to say:-
This Invention relates to improvements designed to simplify the construction
and improve the working of rotatory engines such as are driven by steam.
In one modification of engine constructed with the improvements, a cylin-
drical steam chamber is used having the main shaft passing through its axis
and through stuffing boxes in its end covers. On this shaft is fixed a drum
or closed cylinder of smaller diameter than the chamber, and leaving an annular
space for the steam to work in. The drum is formed with flanges extending
to the cylindrical walls of the chamber, and fitted to work as closely as possible
therewith, and with the end covers but without appreciable friction, and by
preference without packing. A wing or piston is formed or fixed at one part

page_text: of the drum, filling up the channel between the flanges and serving for the
steam to act upon. The inlet and outlet for the steam are situated near each
other in the circumferential part of the chamber and a valve or abutment
piece is introduced between them to prevent the passage of the steam. As
the wing or piston comes round, the abutment valve has to be moved outwards
to allow it to pass, which action is effected by an incline on the front of the
wing or piston. At the same time the entrance of steam is for a moment
shut off by a separate valve acted upon by an eccentric or cam upon the main
shaft. As soon as the wing or piston has passed the steam entrance, the steam
being admitted by the action of the eccentric or cam, forces the abutment
valve back into its place, and the steam exerts its motive force on the piston
as before. In constructing the engine, spring or other packings are dispensed
with, as far as possible, and the parts are accurately shaped to work with as
little friction as possible, and yet as closely as to avoid any material passage of
steam. In some cases, however, as in engines of large size for example, light
spring packings may be applied to the edge of the wing or piston and to the
edges of the abutment valve. The details are susceptible of various modifica-
tions; thus the channel in the drum may be either rectangular or of a curved
or other convenient form. Two or more cylinders may be applied adjacently on
the same shaft, with the wings or pistons of each placed at different points;
or there may be in one cylinder two or more entrances and outlets for the
steam and two or more wings or pistons..
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Andrew Blair in the Great Seal Patent, Office on the 6th
September, 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, "ANDREW
BLAIR, of Dawsholm Print Works, in the County of Dumbarton, North
Britain, Calico Printer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of March; in the year of our Lord One
thousand eight hundred and sixty-two, in the twenty-fifth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Andrew Blair, Her special licence, that I, the said Andrew Blair, my execu-
tors, administrators, and assigns, or such others as I, the said Andrew Blair,
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

page_text: expressed, should and lawfully might make, use, exercise, and vend, within the
United Kingdom of. Great Britain and Ireland, the Channel Islands, and Islo
of Man, an Invention for "IMPROVEMENTS IN ROTATORY ENGINES,". upon the.
condition (amongst others) that I, the 'said Andrew Blair, 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 Andrew Blair, 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,
in writing; reference being had to the accompanying. Drawings, and to the
letters and figures marked thereon, that is to say:
My said Invention relates to improvements designed to simplify the con-
struction and improve the working of rotatory engines such as are driven
by steam.
And in order that my said Invention and the manner of performing the same
may be properly understood, I have hereunto appended a Sheet of explanatory
Drawings to be referred to in particularly describing my improvements.
Figures 1 and 2 of the Drawings, are vertical sections taken at right
angles to each other of an improved rotatory engine, arranged for turning in
one direction only. Figure 3, is a transverse sectional elevation showing the
application to the engine of a cut off valve with variable expansion gear;
and Figure 4 is a transverse vertical section of a modification of the engine
arranged so as to be driven in either direction. The same reference letters
mark the same or like. parts in all the Figures. In the modification of my
improved engine shown in Figures 1 and 2, a cylindrical steam chamber A is
used, having the main shaft B passing through its axis and through stuffing.
cboxes C, in its end. covers D. On this shaft B is fixed a drum or closed
cylinder E, of smaller diameter than the chamber or case A, and leaving an
annular space F for the steam to work in. The drum E is formed with flanges
or flanged ends G, extending to the cylindrical walls A, of the chamber, and
fitted to work as closely as possible therewith, and with the end covers D, but
..without appreciable friction, and by preference without packing. To reduce
the friction between the flanges G and the end covers D, these are
made to bear upon each other only at the circumference and near the
centre; and should any steam get between the flanges and covers its further
egress will be prevented by the stuffing boxes C.. A wing or piston H is fixed.

page_text: (or formed) at one part of the drum E, filling up the channel F between the
flanges G, and serving for the steam pressure to act upon. The inlet I and
outlet J for the steam are situated near each other in the circumferential
part A of the chamber, and a valve, slide, or abutment piece K is introduced
between them to prevent the passage of the steam. The wing or piston H
is formed with inclined sides, and as it comes round it moves the abutment
valve K outwards in order to pass it, at the same time the abutment valve K
shuts off the steam by covering the inner end of the inlet passage or port I.
The abutment valve K is fitted to work in a groove or box, the lower part of
which serves as a stuffing box, and the groove or box is lined with brass, the
upper end being exposed to the steam pressure in the steam chest L. As
soon as the outer edge of the piston or wing H passes the abutment valve K,
this last is caused, by the steam pressure on its outer end, to move inwards,
and by the time it has reached its inner position its outer edge will have un-
covered the inlet passage or port J, and the steam will have access to the
chamber, and exerting its motive force on the piston H, as before, will continuo
the rotation of the drum E. The momentum of the moving parts and of the
fly wheel M serves to carry the wing or piston H past the dead point when
the steam does not act upon it. Or two engines may be combined with their
pistons at opposite parts of their respective drums. If preferred the inlet
port I, instead of being closed by the abutment valve K, may be closed by a
separate valve acted upon by an eccentric or cam on the main shaft. In the
modification shown in Figure 3, a valve N is fitted to work in the steam
chest L, to regulate the access of the steam to the abutment valve K and
port I. This valve N is worked by a lever P fast on a spindle Q, turning in
bearings on the cylinder flanges, and having fast on its outer end a lever R,
fitted with a moveable pin, adjusted by means of a screw S, and actuated by
the rod T, of an eccentric U, on the main shaft B. By adjusting the eccentric
rod T up or down the lever R, it may be made to cut off the steam at a later
or earlier period of tho revolution, thus giving the power of working. the engine
more or less expansively. A simple means of cutting off the steam before tho
piston reaches the dead point is indicated by a dotted line at V, in Figure 1.
this line representing a piece for increasing the diameter of the drum E, some
distance in advance of the piston H, this piece being of a thickness to move
the abutment valve K outwards sufficiently far to close the inlet port I.
Figure 4 represents an arrangemant of valves for reversing the direction of
rotation. A cylindrical chamber W is formed towards each side of the abutment
valve K, each chamber having an inlet port I, communicating with the box
in which the abutment valve K works. There is also an exhaust port &, and a

page_text: cylinder port y, in each chamber W, and on a spindle passing through the centro
of each chamber there is a diametrical valve Z, the position whereof determines
the side on which the steam enters, and that on which the steam leaves the
cylinder. The spindles of the valves Z, have levers a fixed upon them exter-
nally, and these levers are connected by a link b, so that the valves may be
shifted simultaneously. In constructing the engine, spring or other packings
are dispensed with as far as possible, and the parts are accurately shaped to
work with as little friction as possible, and yet as closely as to avoid any
material passage of steam. In some cases, however, as in engines of large size
for example, light spring packings may be applied to the edge of the wing or
piston, and to the edges of the abutment valve. The details are susceptible of
various modifications, thus the channel in the drum may be either rectangular
or of a curved or other convenient form. Two or more cylinders may be
applied adjacently on the same shaft, with the wings or pistons of each placed
at different points, or there may be in one cylinder two or more entrances and
outlets for the steam and two or more wings or pistons.
Having thus particuliarly described my said Invention, and the manner in
which the same is or may be performed, I have to state that I do not restrict
myself to the precise details herein described or delineated, but that what I
consider to be novel and original and claim as the Invention secured to me
by the herein-before in part recited Letters Patent, is, the constructing of
rotatory engines substantially as herein described and delineated.
In witness whercof, I, the said Andrew Blair, have hereunto set my hand
and seal, this Fourth day of September, in the year of our Lord One
thousand eight hundred and sixty-two.
Witness,
EDMUND HUNT,
Patent Agent,
28, St. Enoch Square,
Glasgow.
ANDREW BLAIR. (L.S.)