IMPROVE- MENTS IN ENGINES WORKED BY STEAM OR OTHER FLUID."
Year: 1880

page_text: LETTERS PATENT to James John Miller and Gerald John Tupp, both of
Hammersmith, in the County of Middlesex, for an Invention of "IMPROVE-
MENTS IN ENGINES WORKED BY STEAM OR OTHER FLUID."
PROVISIONAL SPECIFICATION left by the said James John Miller and
Gerald John Tupp at the Office of the Commissioners of Patents on the
4th December 1880.
JAMES JOHN MILLER and GERALD JOHN TUPP, both of Hammersmith, in the
County of Middlesex. "IMPROVEMENTS IN ENGINES WORKED BY STEAM OR OTHER
FLUID."
The object of our Invention is to provide a simple method of reversing steam
and other engines, which we effect by making the inlet and exhaust passages to
and from the cylinder mutually interchangeable, so that the passage which is the
inlet for actuating fluid when the engine is running forwards becomes the exhaust
outlet when the engine runs backwards.
This interchange or reversal of office of the passages may be effected by the use,
in conjunction with an equilibrium or balanced distributing valve, of a slide, piston,
equilibrium, or other valve or valves, or, in the case of small engines, of a fourway
cock, whereby that part of the cylinder that is normally the exhaust may be put
into communication with the supply, and the appropriate port, that is normally an
inlet, into communication with the exhaust (for example, the funnel, in the case of
a steam launch), thus effecting the desired reversal. Or sets of clack valves
working alternately, or slide or piston valves taking the place of the ordinary slide
valve, and furnished with two sets of ports, may be so arranged that either set of
such ports can be brought into action by moving the valve so as to reverse the
position of its passages with regard to the steam and exhaust passages for the
purpose of reversing, as above set forth.
Our Invention may be applied to various kinds of engines with one or more
cylinders or compound.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James John Miller and Gerald John Tupp in the Great Seal Patent
Office on the 4th June 1881.
JAMES JOHN MILLER and GERALD JOHN TUPP, both of Hammersmith, in the
County of Middlesex. "IMPROVEMENTS IN ENGINES WORKED BY STEAM OR OTHER
FLUID."
The object of our Invention is to provide a simple method of reversing steam
and other engines, which we effect by making the inlet and exhaust passages to
and from the cylinder mutually interchangeable, so that the passage which is the
inlet for actuating fluid when the engine is running forwards becomes the exhaust
outlet when the engine runs backwards.
This interchange or reversal of office of the passages may be effected by the use,
in conjunction with an equilibrium or balanced distributing valve, of a slide,
piston, equilibrium, or other valve or valves, and in the case of small engines of a
fourway-cock, whereby that port of the cylinder that is normally the exhaust may
be put into communication with the supply, and the appropriate port, that is
normally an inlet, into communication with the exhaust (for example, the funnel,
in the case of a steam launch); thus effecting the desired reversal. Or sets of clack
valves working alternately, or slide or piston valves taking the place of the ordinary
slide valve, and furnished with two sets of ports, may be so arranged that either
set of such ports can be brought into action by moving the valve so as to reverse
the position of its passages with regard to the exhaust and steam passages for the
purpose of reversing, as above set forth.
Our Invention may be applied to various kinds of engines simple, with one or
more cylinders, or compound.
Referring to the accompanying two Sheets of Drawings, Fig. 1 is a central
longitudinal sectional elevation shewing the steam distributing and reversing
valves or apparatus of an engine, according to our Invention, driven by steam or
other actuating fluid, and Fig. 2 is a plan of the same.
A is the plug of a four way cock acting as the reversing valve, and shewn in the
position in which it stands when the engine is running ahead or in its normal
direction.
B, C, D, E, are the four orifices of the cock, of which, when the plug is in the
position represented in the Drawings, B is the steam inlet, D the steam outlet to
the distributing valve chest, E the inlet for the exhaust steam from the cylinder
to the cock, and C the exhaust outlet; F is a piston valve of the ordinary type,
end distributes the steam or other actuating fluid to the cylinder of the engine
through the ports G and H, shewn in dotted lines.
Supposing the valve F to be moving in the direction of the arrow the course of
the steam would be to enter at B, to traverse the passage D, to turn along the
port H to the main piston and propel it forward. At the same time the motion
of the valve would uncover the port G, and allow the steam from the forward end
of the cylinder to escape along the passage E and through the outlet C. If however
the fourway cock were turned through a quarter of a circle the engine would be
reversed by the steam being admitted in the first instance to the main piston by
the port G instead of by the port H as just described. In that case the course of
the steam would be from the inlet B, through the plug A, down the passage E, and
into the port G,.while the port H and the steam chest would be in communication
with the exhaust outlet C through the passage D and plug A.
Fig. 3 is a central longitudinal sectional elevation shewing the distributing and
reversing valves of an engine in which the interchange or reversal of office of the

page_text: ports or passages is effected by means of a slide valve, and Fig. 4 is a plan of the
same.
I is the slide reversing valve working in the steam chest J which communicates
with the chest of the piston distributing valve K by the two passages Land M,
each of which may act either as the inlet of live steam to the distributing valve,.or
the outlet of exhaust steam from the same valve.
N is the exhaust outlet .communicating, it may be to the condenser, or, in the
case of a steam launch, to the funnel; O is the handle whereby by means of the
spindle P and crank or arm Q (whose pin Q' works in a transverse slot in
the valve I) the valve I may be moved to cover the ports or passages Land N, and
to open or expose the passage M; R is the valve spindle, and S, T, the ports of the
cylinder whose piston is to be controlled or reversed. With the parts in the
positions shewn in the Drawings, that is, as they are in an engine set to run ahead
or in its normal direction, and with the piston approaching the end of the back ward
stroke, the steam passes from the chest J down the passage L, and, as the valve
moves in the direction of the arrow, into the cylinder by the port S, while the same
movement of the valve connects the opposite end of the cylinder through the
port T and the passage M to the exhaust outlet N. When the valve I is moved to
cover the ports or passages L and N and to open the passage M, the steam under
the same circumstances as those hereinabove just described passes from the chest J
down the passage M and into the port T, while the port S and the valve chest are
put in communication with the exhaust outlet N through the passage L.
Fig. 5 is a longitudinal sectional elevation of a slide valve having two sets of
ports so arranged that either set of ports can be brought into action by moving
the valve; and Fig. 6 is an elevation shewing the steam chest with the valve
and mechanism for effecting its reversal partly drawn in dotted lines.
A is the slide valve which is moved or operated by the bridle B. This valve has
two sets of ports, one on each side of the rib or dividing bar C. The upper set of
ports is designed for use when the engine is to run forwards and the lower set for use
when it is to run backwards; D, E, are the steam ports of the cylinder, shewn in
dotted lines; and F, the exhaust port. I is the reversing handle, which by means
of the spindle J and arm or crank K serves to traverse the valve sideways in its
bridle, and to bring when required the lower set of valve ports over the cylinder
ports D, E, and F.
When the valve is in the position shewn and moving in the direction of the
arrow the port E is just opening to the steam chest, and the port D to the exhaust
cavity of the slide valve. If, however, the valve were carried by the reversing
handle into its other position, the port D would be just opening into the steam
port D¹, which is cut right through the valve as if it were a plate valve, while the
port E would be opening into the exhaust cavity F¹ of the valve.
Fig. 7 is a longitudinal section of a steam chest containing a piston distributing
valve with two sets of ports so arranged that either set may be brought into action
by moving the valve, so as to reverse the position of its passages with regard to the
exhaust and steam passages of the engine for the purpose of reversing the said
engine.
H is the valve, which can be turned half round or through 180 degrees by the
handle I and spindle J connected to the valve by a pin K working in a slot L of
sufficient length to allow of the travel of the valve. By this semi rotation of the
valves the ports P', Q', R¹, R¹, are brought opposite to the ports M, O, N, in the
valve face, and take the place of the ports P, Q, R. With the valve in the position
shewn and moving in the direction of the arrow, the steam entering the central
cavity of the valve at the left hand end passes by the port P into the port M,
while the steam in the cylinder exhausts through the port N into the exhaust
opening R.
When the valve H is turned through 180 degrees around its longitudinal axis
the course of the steam, supposing the parts to be otherwise in the position shewn

page_text: in the Drawings, would be as follows:-The steam from the central cavity of the
valve passes as the valve. moves to the right through the steam port P of the
valve into the port N of the cylinder, while the exhaust steam from the opposite
end of the cylinder escapes into the port R³, and from thence to the exhaust
outlet S.
Fig. 8 is a side elevation of a compound engine fitted with reversing apparatus
according to our Invention; it may be either the apparatus described with
reference to Figs. 1 and 2, or to Figs. 3 and 4, or to Figs. 5 and 6, or to Fig. 7.
1 is the high pressure cylinder; 2, the low pressure cylinder; 3 and 4, the spindles
of the reversing valves of the high and low pressure cylinders respectively; 5, a
coupling rod; and 6, a hand lever for simultaneously operating the two reversing
valves.
When the engine is standing with the crank in certain positions both of the
steam ports of the high pressure cylinder are covered by the valve, and conse-
quently the steam cannot penetrate into either cylinder, and the engine will not
start. Under such circumstances a cock in the pipe 10, which is for the purpose of
admitting steam direct from the boiler to the low pressure cylinder, is opened, and
steam admitted at a reduced pressure into the pipe 8, which connects the exhaust
outlet of the high pressure cylinder to the steam inlet of the low pressure cylinder.
Unless, however, there is a check valve in the low pressure steam pipe the steam
acts; under these circumstances, upon opposing sides of the two pistons, and, as it
is free to accumulate in the small cylinder up to the full boiler pressure, while the
relief valves of the large cylinder blow off much below that pressure, it may happen
that the two forces will balance each other, and the engine will not start. To
avoid this difficulty we place in the pipe 8 a check valve 9 between the connecting
pipe 10 and the small cylinder, and as the valve opens towards the large cylinder
the steam pressure when admitted by the pipe 10 closes this valve, and acts only on
the large piston.
Having now described the nature of the said Invention, and explained the
manner in which it is to be or may be performed or carried into practical effect, we
would have it understood that what we consider to be novel and original, and
therefore claim as secured to us under the Letters Patent hereinbefore in part
recited is,―
1. The use for reversing steam and other engines worked by fluid pressure of a
fourway cock in combination with an equilibrium or balanced distributing valve,
the arrangement being such that the offices of the inlet and exhaust passages of the
engine are made mutually interchangeable, substantially as described with reference
to Figs. 1 and 2 of the Drawings.
2. The use for reversing steam and other engines worked by fluid pressure of a
slide valve in combination with an equilibrium or balanced distributing valve, the
arrangement being such that the offices of the inlet and exhaust passages of the
engine are made mutually interchangeable, substantially as described with reference
to Figs. 3 and 4 of the Drawings.
3. The use for reversing steam and other engines worked by fluid pressure of a
slide valve, taking the place of the ordinary slide valve, and furnished with two
sets of ports, so arranged that either set of ports can be brought into action by
moving the valves, such ports being so disposed that the act of moving one set of
such ports out of and the other set of such ports into position over the ports of the
cylinder effects the reversal or interchange of office of the passages of the valve with
regard to the exhaust and steam passages, substantially as described with reference
to Figs. 5 and 6 of the Drawings.
4. The use for reversing steam and other engines of a piston valve, taking the
place of the ordinary slide or piston valve, and furnished with two sets of ports, so
arranged that either set of ports can be brought into action by moving the valve,
such ports being so disposed that the act of moving one set of such ports out of and
the other set of such ports into position over the ports of the cylinder effects the

page_text: reversal or interchange of office of the passages of the valve with regard to the
exhaust and steam passages, substantially as described with reference to Fig. 7 of
of the Drawings.
5. Arranging a compound steam engine so that the inlet and exhaust passages
are made mutually interchangeable, as and by the means above explained, and
that when the passages have been so reversed the engine will readily start, as
described with reference to Fig. 8 of the Drawings.
In witness whereof, we, the said James John Miller and Gerald John Tupp,
have hereunto set our hands and seals, this Fourth day of June, in the
year of our Lord One thousand eight hundred and eighty one.