IMPROVEMENTS IN ROTARY ENGINES AND PUMPS
Year: 1874

page_text: LETTERS PATENT to George Tomlinson Bousfield, of Sutton, in the
County of Surrey, for the Invention of "IMPROVEMENTS IN ROTARY
ENGINES AND PUMPS."-A communication from abroad by William
Robinson Manley, of the City of New York, in the United States of
America
COMPLETE SPECIFICATION filed by the said George Tomlinson Bous-
field at the Office of the Commissioners of Patents, with his Petition
and Declaration, on the 5th January 1874, pursuant to the 9th
Section of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
TOMLINSON BOUSFIELD, of Sutton, in the County of Surrey, send
greeting.
WHEREAS I am in possession of an Invention for "IMProvements
IN ROTARY ENGINES AND PUMPS," and have petitioned Her most Excellent
Majesty Queen Victoria to grant unto me, my executors, admini-
strators, and assigns, Her Royal Letters Patent for the same, and

page_text: have made solemn Declaration that it is a communication to me from
abroad by William Robinson Manley, of the City of New York, in the
United States of America.
NOW KNOW YE, that I, the said George Tomlinson Bousfield, do
hereby declare the nature of the said Invention, to be as follows :—
The Invention which constitutes the subject-matter of this Patent has
reference to that class of rotary engines in which two or more pistons
are caused to revolve or rotate in a cylinder or case, and it is applicable
in whole or in part to steam engines, pumps, fluid meters, and blowing or
other engines in which it or parts of it may be useful. The objects of
the Invention are to obviate the defects incident to the circular move-
ment of a piston or pistons in contact with heads fixed to the cylinder or
case confining the fluid, also to work the steam with variable expansion,
to pack the moving parts steamtight, to sustain the pistons at their ends,
to cause them to move properly, to prevent the leakage of steam from
the cylinder, and to equalize the steam pressure upon the exteriors of
rotary cylinder heads. To these ends the Invention consists primarily of
the combination of a fixed cylinder or case with one or more revolving
pistons, and with cylinder heads which revolve with the piston or
pistons, so that the unequal wear incident to the circular movement of
the piston or pistons upon fixed heads is obviated.
The Invention consists further of certain other combinations and con
structions which are specified at the close of this Specification.
The improvements may be embodied in various forms, and some of
them may be used without others, so that the construction of a steam
engine may be greatly varied without ceasing to embody my Invention
in whole or in part.
In order that, the Invention may be fully understood I have repre-
sented in the accompanying Drawings, and will proceed to describe a
rotary engine embodying all the parts of the Invention in a good practical
form.
Figure 1 represents an end elevation of the said engine, Figure 2
represents a plan of the same, Figure 3 represents a vertical longitudinal
section of the same, Figures 4, 5, and 6, represent transverse sections of
the same at the lines X, X, Y, Y, and Z, Z, respectively of Figure 3.

page_text: Figures 7 and 8 represent views of detached parts of the engine
designated by the same letters of reference as the same parts in the other
Figures.
The engine represented in the Drawings has a cylinder or case A,
which in this example is made fast to the bed plate B. This cylinder is
closed at both ends by heads G, and constitutes a cylindrical cavity in
which the pistons rotate. The pistons C in this example are six in
number, and are connected with a hub D, which is arranged to revolve
within the cylinder and eccentrically with the cavity thereof. The hub
D is supported by the gudgeons E, E, which are arranged to revolve in
pillow blocks F secured to the bed plate B. The sides of the cylinder A
are closed by heads G, G, which are rigidly connected with the piston
hub D, so that the hub, heads, and pistons all revolve together. The
rims of these heads cover the flanges h.of the cylinder A, and the joints
between the two are packed by preference with metallic rings m, which
are contained in ring grooves in the cylinder, and are pressed towards the
inner faces of the heads by springs; these packing rings are concentric
or thereabouts with the cylinder and eccentric to the cylinder heads G.
The pistons C in the present example are six in number. Each piston.
C is constructed to slide radially in a slot in the revolving piston hub,
and the sides of the piston are packed (see Figure 6) by means of
metallic packing bars a, which are arranged in grooves at the opposite.
sides of each slot, and are pressed towards the faces of the piston by
springs arranged behind the bars in the grooves. The outer edge of each
piston (C) is provided with a rocking shoe b, which is connected with
the piston by a pivot joint c, and revolves in contact with the inner
surface of the cylinder to which it adapts itself by rocking.
In order that a slight movement of the piston relatively to the shoe
may be permitted, the pivot of the joint is constructed with a plate
shank (see Figures 5 and 6) which is received in a groove in the outer
side of piston, and the shank is pressed outward by springs inserted in
the groove.
In order that the pistons may be sustained against the pressure of.
the steam the revolving cylinder heads are grooved radially, and each
end of each piston (in the vicinity of the cylinder heads) is connected
with a slide, which is constructed to slide radially in one of the...
grooves of the cylinder head, so that the pistons are guided and

page_text: sustained by the heads as the pistons slide to and fro. in the slots of
the piston hub D.. The said piston slides may be constructed separately
from the pistons and secured to them, or may be constructed in one
piece with their respective pistons if deemed expedient. In order that
the sliding pistons may be positively drawn out of the hub D the ends
of the piston slides are extended beyond the circumference of the
cavity of the cylinder, and their extended ends are fitted with friction
wheels e, which are received in guiding ring grooves n formed in the
cylinder flanges h, so that the action of the sides of the said ring
grooves upon the slides / causes them, with the pistons, to move
properly as the pistons rotate. If preferred slide blocks may be
substituted for the friction rollers e, each slide block being connected
with its respective slide by means of a pivot. The guiding grooves n
are not precisely concentric with the cavity of the cylinder, because as
the piston hub D is eccentric to that cavity the slides are sometimes
exactly radial to that cavity, and are at other times oblique to the
radial lines thereof; and consequently if the guiding grooves were
concentric with the cavity of the cylinder the distance between the
centre of the sole of a piston shoe 6 and the inner side of the guiding
groove, measured along the longitudinal centre of a piston slide when
in its oblique position, would have to be greater than the distance
between the same two surfaces when the piston slide was radial to that
cavity.
In order that the distance between the centre of the sole piston shoe
and the friction roller of the guiding groove, measured in the line of
the piston slide, may remain the same in all positions which the piston
slide assumes the guiding grooves are made of the requisite eccentricity
to the cylinder cavity and of an imperfect elliptic form. The precise
form for this purpose is readily obtained by causing one of the pistons
to revolve in the cylinder with its shoe pressed against the inner surface
of cylinder, and by marking the track described by the centre of the
•hole in the piston slide for the pivot of the friction wheel. The line
thus described will be the central line of the guiding groove, from
which the lines of its sides may be laid out by measurement.
When the guiding grooves are formed as described the pistons shoes
are held against the surface of the cylinder with practically equal
pressure through their revolution.

page_text: Steam is admitted to the cylinder at one side of its central diametrical
line (ff, Figure 6) by the steam ports d, d', which communicate
with the steam chest H; and the steam is permitted to escape at the
opposite side of the central diameter through the exhaust ports d³, d³,
d', d³, which communicate with the exhaust chest I.
In order that the steam may be worked with a variable expansion,
or in other words may be cut off at variable portions of the travel of
the pistons, the steam port is divided into a series of openings ḍ,
extending from the first place 9 where steam is to be admitted to the
furthest place g¹ at which the steam is to be cut off, and a valve s
(Figures 7 and 8) is applied to the outer orifices of these openings, so
that more or less may be uncovered at will. The entrance of steam
can take place only through the uncovered openings, consequently as
soon as any one piston passes by those openings which are uncovered
the supply of steam to the last preceding piston is cut off, and the
period of cut off may be varied by moving the cut off valve s.
The construction of cut-off valve and valve openings, thus described,
also enables the cut-off valve to be used if desired as the throttle valve
of the engine. Or it may be connected with the slide of a governor,
so that the cut-off may be varied automatically.
In order that the admission of steam may be continuous from the
commencement to the end of the portion of the movement during which
steam may be admitted to act upon a piston two series of steam
openings d; d, of the divided steam port are provided, and the inner
orifices of one series are arranged horizontally opposite the spaces
between the inner orifices of the other series, so the orifices of the two
series alternate, and that the piston passing by said orifices will receive
steam continuously from an opening of one series or of the other at
every part of its revolution, during which cut-off may be effected.
In order that the cut-off valves may be moved with facility the cut
off valve is constructed double faced, or with faces at its opposite sides,
and the outer orifices of the steam port are arranged opposite each
other, with the valve between them, as seen at Figure 8, so that the
steam pressure at opposite sides of the valve is balanced; and in order
that the seats in contact with which the cut-off valve slides may be
adjusted one or both of the series of the exterior orifices of the steam,
0

page_text: ports are constructed in movable plates ", which are secured in place by
screws.
It is desirable that the steam should be permitted to exhaust as
soon as it has attained the greatest expansion of which the engine
admits. To this end the engine has an exhaust port d² arranged at a
distance from the exhaust side of the central diameter f, equal to half
of the peripheral distance between two adjacent piston shoes, or
thereabouts, so that the exhaust will commence from the space j
between two pistons, when they are at about equal distances at opposite
sides of the central diameter f, f, (as represented in dotted lines in 1
Figure 6) at which time the variable space enclosed between the pistons
is greatest.
In order that the exhaust may be permitted to continue to the last
moment practicable, additional exhaust ports d³, d³, d³, are used, so that
the steam may exhaust through them after the exhaust through the 1
first port (d²) is cut off by the passage of the piston over it.
For the sake of clearness in the Drawing the piston hub D is
represented as separated from the surface of the cylinder at the nearest
point between the last exhaust port and the first steam port by a con-
siderable space; but in practice the piston hub is made so large that it 2
just clears the surface of the cylinder, so that the dead space between
the last exhaust port and the first steam port may be a minimum.
In order that the heads of the steam cylinder may be kept warm,
head jackets K, K, are provided. These are secured steam tight to the
flanges of the cylinder, and they have packing boxes t, t, at their central 2
openings for the piston shaft or gudgeons E, so that the escape of steam
or water from the jackets is prevented unless it is drawn off by a cock.
Consequently the steam which may leak past the packings of the
revolving cylinder heads is caught and retained in the jackets, and the
water produced by the condensation of such steam acts as a lubricator 3
for the working parts.
In order to equalize the pressure upon the exteriors of the two
cylinder heads at opposite ends of the cylinders, the spaces within the
jackets are combined by a transverso equalizing passage w, through

page_text: 1
into the piston hub directly from the steam boiler when the engine
is to be started. The bore of the cylinder in this example is not a
true cylinder, but is formed of two intersecting segments of cylinders
of different radii. One of these segments extends from 6 to 6' in the
direction of the arrow a, Figure 9, and is concentric with the piston
hub but of slightly larger diameter, so that the piston hub just clears
it; the other segment extends in the same direction from b¹ to b,
Figure 9, is of much larger diameter than the piston hub, and is
eccentric thereto.
- It will be noticed that in an engine constructed as either of the
two above described the pistons or the piston slides slide radially in
contact with the surfaces of the heads, but do not revolve against
them. As in such radial sliding all the parts of the pistons or piston
slides in contact with the heads move the same lineal distance, the
wear is equalized, and unequal wear of the pistons is prevented;
whereas if the edges of the pistons turned in contact with the fixed
cylinder heads (as has heretofore been common), the inner ends of
the pistons would describe smaller circles than their outer ends, and
consequently the former would travel shorter lineal distances than
the latter, the result of which would be unequal wear and constant

page_text: 4th. Also the combination, substantially as before set forth, of the
fixed cylinder, the revolving cylinder heads, the piston hub, the sliding
piston, and the bar packing between the piston and the piston hub.
5th. Also the combination, substantially as before set forth, of the
fixed cylinder, and the cylinder heads arranged to revolve eccentrically
to the said cylinder, and provided with radial grooves for guiding and
sustaining the pistons.

page_text: heads, the head jackets, and the equalizing passage connecting the said
jackets.
In witness whereof, I, the said George Tomlinson Bousfield, have
hereunto set my hand and seal, this Twenty-third day of
December, in the year of our Lord One thousand eight hundred 5
and seventy-three.