Improvements in and relating to Rotary Engines.
Year: 1899

page_text: Improvements in and relating to Rotary Engines.
I, DAVID TULLOCH, of 94; Marshall Street, Grangemouth, in the County of
Stirlingshire, Shipwright, do hereby declare the nature of my invention to be
as follows:-
This invention has reference to improvements in and relating to rotary engines
which can be worked by steam or other fluid either at high pressure or expan-
sively.
The improvements consist of a wheel mounted on a shaft and fitted eccen-
trically with a vane or piston to rotate round axis of wheel inside a chamber.
This cylinder is fitted on opposite sides of wheel with two sliding partitions
which when closed will divide the cylinder into two equal divisions. These
partitions slide in grooves formed in the cylinder, and they are reciprocated or
worked by two eccentric guide wheels, which are mounted on the shaft one on
each side of engine, or alternatively the vane wheel may be made to work these
partitions in place of the outside guide wheels. When the piston is halfway
between the partitions, both of these are closed for a short time, and they being
thus closed gives the fluid pressure time to exhaust. The partition behind the
piston acts as a cylinder-end, and the steam coming in between this partition and
piston causes the piston to turn the wheel. The guide wheels having the same
eccentric shape as the wheel causes the partition before it to open and allows it
to pass, and when the piston is past, the guide wheels pull back the partition
with the same action as they opened it. This partition is now the one that is
behind the piston and it acts as the cylinder-end for the next half turn. Imme-
diately the partition closes, the exhaust valve opens and allows the steam which
was left in the space between the partitions, to escape. The steam which followed
the piston fills one quarter of the cylinder and is still pressing the piston by its
expansion. At the same time as the exhaust valve opens the steam supply also
opens and presses the quarter cylinder of reduced steam up and so keeps on a
constant pressure.
The other half turn is just a repeat of the former so, that there is a constant
turning and constant pressure both in the same direction.
To reverse the action of the engine the steam ports which enter into the
cylinder are placed on both sides of the partitions, but one is shut and not used
when the engine is worked in the reverse direction. The other is the working
port, it being between the partition and the piston, and may feed the cylinder
for half a turn or may be cut off at any part to make the engine work expan
sively. The exhaust ports are constructed and worked in the same manner. The
only time that an exhaust port is closed is when the piston is passing a partition
and until this partition is closed, a little more than a quarter of a turn, for a
full revolution of the engine.
The cylinder being long might expand or reduce the pressure as much as
necessary, or by enlarging the diameter of the engine-disc and giving it more
stroke would lengthen the cylinder and give more leverage and consequently

page_text: more power or a less size of cylinder. For large engines the partitions could
be opened and shut by slides, or wheels could be used to open and close them.
Dated the 2nd June 1899.
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.
:
I, DAVID TULLOCH, of 94, Marshall Street, Grangemouth, in the County of
Stirlingshire, Shipwright, do hereby declare the nature of my invention and in
what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement, that is to say:-
This invention has reference to improvements in and relating to rotary engines
which can be worked by steam or other fluid either at high pressure or expan-
sively.
And in order that my said invention and the manner of carrying same into
practice may be properly understood, I have hereunto appended a sheet of
explanatory drawings in which Figure 1 is a sectional elevation and Figure 2
a sectional plan view of a rotary engine as constructed in accordance with my
improvements, the rotating wheel A being shown broken away in Figure 1.
Referring to these drawings:
The improvements consist of a wheel A mounted on a shaft A¹ and fitted
eccentrically with a vane or piston A² to rotate round axis of wheel inside a
cylinder B B a casing B being formed inside the cylinder. This cylinder B B²,
is fitted on opposite sides of wheel A with two sliding partitions C, C', which
when closed will divide the cylinder into two equal divisions.
These parti-
tions C, C', slide into chambers G G forming housings outside of the cylinder,
and they are reciprocated or worked by two eccentric guide wheels D, D', which
are mounted on the shaft A' one on each side of engine, or alternatively the vane
wheel A may be made to work these partitions C and C in place of the outside
guide wheels. When the piston A2 is halfway between the partitions C, C, as
shown in Figure 1 both of these are closed for a short time and they being thus
closed gives the fluid pressure time to exhaust through the pipes E¹ and valves e
which are both open at this time. The partition C behind the piston A³ acts
as a cylinder-end, and the steam coming in between this partition and piston
causes the piston to turn the wheel A. The guide wheels D, D', having the
same eccentric shape as the wheel A cause the partition before them to open and
allow it to pass, and when the piston is past, the guide wheels pull back the
partition C with the same action as they opened it. This partition C¹ is now
the one that is behind the piston and it acts as the cylinder end for the next
half turn. Immediately the partition C¹ closes, the exhaust valve e¹ nearest it
opens and allows the steam which was left in the space B¹ between the partitions,
to escape. The steam which followed the piston fills one quarter of the cylinder
and is still pressing the piston by its expansion. At the same time as the exhaust
valve el last mentioned opens the steam supply valve e nearest to it on same
side of shaft A¹ also opens and presses the quarter cylinder of reduced steam up
and so keeps on a constant pressure.
:
The other half turn is just a repeat of the former so that there is a constant
turning and constant pressure both in the same direction.
The steam valves e and the exhaust valves el are operated by cams H mounted
on the shaft A¹. These cams H are formed at one part with an eccentric or

page_text: raised surface which acts on the hook shaped free ends of levers H¹ having their
other ends attached to the spindles of the valves so as to oscillate the valves and
open or shut them at the proper times. A spring H2 is fitted behind the levers H¹
to bring them back to their normal position on top of cam H.
Figure 1 shows the steam supply pipes E and valves e. The exhaust pipes E
and valves e are on the opposite side of engine and are constructed and worked
in the same manner, except that the ports are on the opposite side of the parti-
tions to that of the steam ports.
The steam is supplied direct from a boiler through a stop cock to these pipes;
and the exhaust steam goes direct from the cylinder through the exhaust pipes
to a condenser or the atmosphere.
To reverse the action of the engine the steam ports e which enter into the
cylinder, are placed on both sides of the partitions C, C¹, but one is shut and not
used when the engine is worked in the reverse direction. The other is the work-
ing port, it being between the partition and the piston, and may feed the cylinder
for half a turn or the steam may be cut off at any part to make the engine work
expansively. The exhaust ports e¹ are constructed and worked in the same
manner. These valves are both open when before the piston. The only time
that an exhaust port is closed is when the piston is passing a partition C or C¹
and remains closed until the piston has moved a quarter of a revolution, and
then both exhausts are open at the same time.
The cylinder being long, by cutting off the steam early, same might expand
or reduce the pressure as much as necessary, or by enlarging the diameter of the
engine-dise and giving it more stroke would lengthen the cylinder and give more-
leverage and consequently more power or for the same power a less size of cylinder.
For large engines the partitions C, C', could be opened and shut by slides, or
wheels could be used to open and close them.
The partition rods F, F, work out through casing, and the partitions open
into chambers G, G¹, and the fluid gets into these chambers and acts on top as
well as underneath partition while the latter is closing or moving into the
cylinder B².
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:-
First. A rotary engine constructed and operated in the manner herein set
forth.
Second. In rotary engines, the arrangement of wheel fitted eccentrically with
a vane or piston to rotate round axis of wheel inside a close chamber, in com-
bination with two sliding partitions, substantially as herein described in reference
to and shown in the accompanying drawings.
Third. The arrangement in combination of the parts of a rotary engine, sub-
stantially as herein described in reference to and shown in the accompanying
drawings.
Dated the 2nd day of March 1900.