IMPROVEMENTS IN ROTARY ENGINES
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by the said Henry Clay Bull at the
Office of the Commissioners of Patents on the 6th September 1883.
HENRY CLAY BULL, of Liverpool, in the County of Lancaster IMPROVEMENTS
IN ROTARY ENGINES
My Invention relates to the construction of rotary engines and to the com-
pounding of the same, and provides a means of reversing the engine.
A compounded and reversible rotary engine according to my Invention consists
of a vessel, having flat sides and a semi cylindrical top and bottom. In the vessel
are placed and work four barrels provided each with four, or more moveable pistons
which are connected in pairs together through the barrels. The barrels are mounted
on shafts which pass through stuffing boxes in the ends of the vessel and work in
bearings outside the vessel, the ends are bolted to the vessel. The vessel is divided
into two parts by a diaphragm, the parts being proportioned one to the other for
expanding the steam from one chamber to the other making them high and low
pressure chambers. The shafts are geared together by toothed wheels and run in
opposite directions, either shaft being provided with power transmitting devices
such as pulleys, discs, or cranks. The steam and exhaust ports are five in number
and are arranged side by side in the engine valve face, the two outside ports lead
to and open out through two passages in each side of the high pressure chamber
which passages are distanced apart equal to one diameter of the piston barrels and
serve as steam and exhaust ports according to the way in which the engine is
running. The intermediate ports lead and open into the low pressure chamber in
a manner similar to those of the high pressure chamber and serve as steam and
exhaust ports to the low pressure chamber according to the way in which the
engine is running, these ports respectively communicate through a valve with the
ports of the high pressure chamber before spoken of, so that the steam after work
in the high pressure chamber finds its way, for work, to the low pressure chamber.
The central port serves as the exhaust port from the low pressure chamber. The
valve which serves as the communicating valve between the high and low pressure

page_text: chambers and as the reversing valve is placed on and works on the engine valve
face and is provided with four ports, nainely two outside ports which are through
ports and serve as the admission ports to the bigh pressure chamber. The inter-
mediate port is an internal port and serves to open communication from the exhaust
port of the high pressure chamber into the admission port of the low pressure
chamber, and is arranged so as to serve for either of the ports of the high and low
pressure chamber according to the way in which the engine is running so that by
the moving of the valve to cover and uncover the respective ports, the direction of
the steam is reversed. The central port is an port and serves to open from the
exhaust of the low pressure chamber to the main exhaust, or central port of the
engine valve face before spoken of and is arranged so as to serve for either of
the ports of the low pressure chamber and the main exhaust according to which
direction the engine is running. Over the communicating valve is placed the
admission valve, which consists of a flat plate with a central opening which serves
as an admission port to the outside ports of the communicating valve, and the valve
is so arranged as to cover both ports and shut off the steam, or to open either of the
ports according to the direction in which the engine is desired to run. The valves
work in a valve chest secured over the engine valve face. Both the communicating
and steam admission valves are provided with spindles which pass through stuffing
boxes in the valve chest. Inside the high and low pressure chambers there are
provided four triangular blocks, two in each chamber and each block having a flat
side to correspond with the flat sides of the chambers.-The flat sides of the blocks
extend between the inlet ports on each side of the chambers. The blocks have
two curved sides which correspond with the curved surfaces of the barrels so that
the blocks come between the two barrels in each chamber. The blocks are placed
centrally one on either side of the chambers and are provided with spindles passing
through stuffing boxes on the respective sides of the chambers. The spindles of
the four blocks are connected by rods so that either two of the blocks on one and
the same side of both chambers can be moved up to the barrels; the other two
blocks on the opposite side being by the same movement brought up to the sides of
the chambers and away from the barrels.
The moveable pistons before spoken of as working in the barrels consist of
rectangular blocks provided with spring packing pieces. These blocks work in
slots in the barrels and each pair are connected together by rods which pass through
the centre of the barrel. The pistons are spaced apart so that when one piston is
against and bearing up to the inner surface of the chamber the other piston is in
the slot of the barrel with its outer surface flush with the periphery of the barrel
The pistons being in this position steam entering the high pressure chamber
through the two passages at one side acts against the projecting pistons, thus
revolving the barrels in opposite directions. As the pistons come round, they come
in contact with the curved surfaces of the block on one side, which is in position
against the side of the chamber This contact forces out the pistons on the opposite
sides of the barrels, which in their turn are acted upon by the pressure of the steam.
The centrifugal force caused by the rotation of the barrels keeps the pistons against
the surface of the chamber. The same action of the pistons takes place in the low
pressure chamber, the steam after use in the high pressure chamber acting on the
pistons in the low pressure chamber, as will be understood. By simultaneously
reversing the position of the valves and the position of the triangular blocks, the
spindles of which are connected together the direction of the motion of the engine
is reversed. The whole engine is mounted on a suitable bed plate or framework to
suit the purposes to which it is to be applied.
Although I have described my Invention as applied to a compound rotary
reversible steam engine, I would have it understood that my Invention may be
applied as a single engine using the steam once only. It is also applicable for use
as a compressed air, or other elastic fluid engine, or as a hydraulic engine.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
t
:
by the said William Clay Bull in the Patent Office on the 3rd March
1884.
HENRY CLAY BULL, of Liverpool, in the County of Lancaster
IN ROTARY ENGINES
"IMPROVEMENTS
My Invention relates to a novel construction of rotary engines and to the
compounding of the same and provides a means of reversing the engine. The
following is a full, clear and exact description of this Invention sufficient to enable
others skilled in the art to which it appertains, or with which it is most nearly
connected to inake, use, and put the same into practice, reference being had to the
sheets of Drawings making a part of this Specification and to the letters and figures
of reference marked thereon, which correspond with those used in this Specifica-
tion, like letters and figures being used to denote the same, or corresponding parts
throughout the various views and figures
DESCRIPTION OF THE DRAWINGS
Figure 1 is an elevation of a compound rotary steam engine according to this
Invention.
Figure 2 is an end view of Figure 1.
Figure 3 is a sectional view of Figure 1.
Figure 4 is a sectional view taken at X X Figure 1.
Figure 5 is a sectional view of the piston of the high pressure steam vessel.
Figure 6 is a plan of Figure 5.
Figure 7 is an end sectional view of Figure 5.
Figure 8 is an elevation of the piston of the low pressure steam vessel.
Figure 9 is an elevation of a compound rotary steam engine fitted with a surface
condenser and air pump according to my Invention.
Figure 10 is an end view of Figure 9.
Figure 11 is a sectional elevation through X X Figure 10.
Figure 12 is a cross section through Y Y Figure 9.
Upon reference to Figures 1. 2. 3. 4. 5. 6. 7 and 8 it will be seen that a compound
and reversible rotary engine (to be driven by, say, steam pressure) consists of a
vessel A having flat sides and a semi oylindrical top and bottom. The vessel A is
divided into two parts by the diaphragm A¹, so as to form high and low pressure
chambers, namely the part B forms the high pressure chamber and is proportioned
to the part C which forms the low pressure chamber, so that the steam after use in
the high pressure chamber B is expanded into and used in the low pressure
chamber C. In the vessel A are placed and work four barrels DD and EE. Each
of these barrels is provided with moveable pistons F which are connected in pairs
by the rods F¹ as shown in detail in Figures 5, 7, and S. Figure 5 showing the
pistons for the high pressure chamber B. Figure S showing the pistons for the low
pressure chamber C. The respective barrels DE and DE are mounted on the
shafts G and H and pass through stuffing boxes I. I. J. J. in the ends of the
vessel A and the shafts G and H are supported by and work in bearings K K LL
outside the vessel A, which bearings are carried by the framework M. of the engine.
The ends A are bolted to the vessel A. The shafts G. H are geared together by
the toothed wheels NO and run in opposite directions. Either of the shafts G, or
H is provided with power transmitting devices such as pulleys, discs, or cranks;
cranks P being shown in the Drawings on the shaft H. The steam inlet and
exhaust ports of the engine are five in number and are arranged side by side in the
engine valve face Q as shown at Figure 4. The two outside ports a a lead to and
open out through two passages a¹ a¹ in each side of the high pressure chamber B.

page_text: The passages a' a' on each side of the high pressure chamber B are distanced apart
equal to one diameter of the piston barrels D D and serve as steam and exhaust
ports according to whichever way the engine is running, namely when the engine
is running one way round the passages on one side serve as steam inlets and the
passages on the other side serve as outlets for the exhaust steam. The intermediate
ports of the engine valve face bb lead to and open into the low pressure chamber C
in a manner similar to the way in which the passages a¹ open into the high pressure
chamber B as before described. In like manner the passages bb serve as steam
and exhaust ports for the low pressure chamber C according to whichever way the
engine is running. The ports b respectively communicate through a valve R with
the ports a of the high pressure chamber B, so that the steam after work in the
high pressure chamber B finds its way for work to the low pressure chamber C.
The central port d serves as the exhaust port from the low pressure chamber C.
The valve R serves as the communicating valve between the high pressure
chamber B and the low pressure chamber C and as the reversing valve. It is
placed on and works on the engine valve face and is provided with four ports,
namely two outside ports e e which are through ports and serve as the admission
ports to the high pressure chamber B. The intermediate port h is an internal port
and serves to open communication from the exhaust port a of the high pressure
chamber B into the admission port b of the low pressure chamber C, and the port h
is arranged so as to serve for either of the ports of the high and low pressure
chambers, according to the way in which the engine is running so that by the
moving of the valve R to cover and uncover the respective ports the direction of
the steam is reversed. The central port k of the valve is a shaped port and
serves to open communication from the exhaust port b of the low pressure chamber C
to the main exhaust, or central port d of the engine valve face and the central
port is arranged so as to serve for either of the ports b of the low pressure
chamber C and the main exhaust d according to whichever direction the engine is
running. Over the communicating valve R there is placed the admission valve S
which consists of a flat plate with a central opening which opening 7 serves as an
admission port to the outside ports e e of the valve R. The valve S is so arranged
as to cover both the ports e e of the valve R and shut off the steam or to open either
one, or the other of the ports e e and admit steam according to the direction in which
the engine is desired to run. The valves RS work in a valve chest T secured over
the engine valve face Q. The valve R is provided with a spindle R¹. The valve S
is provided with a spindle S¹. These spindles R¹ S¹ pass through stuffing boxes in
the valve chest T.
Inside the high and low pressure chambers B C there are provided triangular
blocks U U. The arrangenient and construction of these blocks U U¹ are the
same in both the chambers B C and will be understood on reference to Figure 4;
upon reference to which it will be seen that the blocks U U have a flat side, which
corresponds with the flat side of the chamber and extends between the inlet
ports a¹ a¹ on each side of the chamber. The blocks U U¹ have two curved sides
which correspond with the curved surfaces of the barrels D D and E E, so that the
blocks come between the two barrels in each chamber. The blocks U U¹ are
placed centrally one on either side of the chamber and are provided with spindles
U U passing through stuffing boxes on the respective sides of the chambers B C.
The spindles of the four blocks are connected by rods V so that either two of the
blocks on one and the same side of both the chambers B C can be moved up to
the barrels D E. The other two blocks on the opposite side being by the same
movement brought up to the sides of the chambers and away from the barrels.
The relative position of the blocks U U is shown at Fig. 4.
The moveable pistons F before spoken of as working in the barrels D E are
illustrated in detail at Figures 5. 6. 7 and 8. They consist of rectangular blocks m
provided with packing pieces n, which packing pieces are kept out by the spiral
spring p. These pistons work in slots q which are formed in the barrels D E.
Each pair of pistons F are connected together by the rods F¹ as shown. The pistons

page_text: being spaced apart so that when one piston is against and bearing up to the inner
Burface of the chamber, the other piston is in the slot q of the barrel with its outer
surface flush with the periphery of the barrel, for example as shown at Figure 4.
The piston F being in this position (namely as shown at Figure 4) steam entering
the high pressure chamber B through the passages a' a' in the direction of the
arrows acts against the projecting pistons F thus revolving the barrels D in opposite
directions. As the pistons F travel round, they come in contact with the curved
surfaces of the block U. This contact forces out the pistons F on the opposite
sides of the barrels, which pistons are then acted upon by the pressure of the steam,
the centrifugal force caused by the rotation of the barrels, keeps the pistons against
the surface of the chamber. The steam after use in the high pressure chamber B
passes as before stated through the valve R and ports b to the low pressure
chamber Cand acts in the same way on the pistons of the low pressure chamber C
as will be understood. By shutting off the steam by the valve S and reversing the
position of the blocks U U and the valve R the direction of the motion of the
engine is reversed.
In the engine shown on sheet 2 of the Drawings at Figures 9, 10, 11 and 12, the
exhaust ports d. of the low pressure cylinder C are open to the surface condenser C'
which is fitted with a single acting air pump d' worked from the engine shaft G,
a valve d' is fitted between the condenser Ci and the pump d¹ to make communi-
cation alternately between the bottom of the pump d' and the discharge channel d³
and the condenser C¹. A port d' is formed in the valve d² through which the water
from the pump d' is forced. Whilst the valve d² is at the bottom of its stroke
communication between the condenser C¹ and the pump d¹ is closed and the port d'
of the valve d is open to the interior of the pump d. In this example the blocks
U U of the low pressure chamber C are not moveable, but form part of the
vessel C.
Although I have described my Invention as applied to a compound rotary
reversible steam engine, it must be understood that my Invention may be applied
as a single engine using the steam once only. It is also applicable for use as a
compressed air, or other elastic fluid engine, or as a hydraulic engine.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed, I claim
First In a rotary engine, the combination of two barrels having moveable pistons
rotating in opposite directions within a chamber provided with inlet and outlet
ports, the engine operating as herein described and constructed as shown in the
Drawings hereto annexed.
Second In a rotary engine a piston packing consisting of packing pieces n
spring p and a block m substantially as herein described and shown in the Drawings
hereto annexed.
Third The arrangement and construction of a compound rotary steam engine, as
herein described and shown in reference to Figures 1 to 8 inclusive of the Drawings
hereto annexed.
Fourth The arrangement and construction of a compound rotary steam engine as
herein described and shown in reference to Figures 9 to 12 inclusive of the Drawings
hereto annexed.
In Witness whereof, I, the said Henry Clay Bull have hereunto set my hand and
seal this twenty second day of February in the year of our Lord one thousand
eight hundred and eighty four.
HENRY CLAY BULL (L.S.)