Improvements in Compound or Tri-compound Steam Engines.
Year: 1896

page_text: Date of Application, 2nd Mar., 1896
Complete Specification Left, 30th Nov., 1896-Accepted, 13th Feb., 1897
PROVISIONAL SPECIFICATION.
Improvements in Compound or Tri-compound Steam Engines.
1, MATTHEW HENRY PHINEAS RIALL SANKEY, of Ferry Works, Thames
Ditton, in the County of Surrey, Engineer, do hereby declare the nature of this
invention to be as follows:-
In cases where it is desired to admit steam, either for starting, or for the sake of
increased power to the low pressure cylinder or cylinders of a compound engine,
I form the relief valves upon the H.P. cylinder or cylinders as slide-valves, able
to lift against the resistance of a spring holding them upon their seats, and dis-
charging the water or vapour from the cylinder into a passage connected with the
steam chest. The valves are moved in the usual way by spindles passing through
glands, cither by suitable hand-gear, or by the action of the governor acting either
directly or through a relay cylinder, or by electrical means, as by a solenoid
actuated by the increase or decrease of an electrical current.
I apply these valves as an adjunct to the apparatus for automatically varying
the cut-off in steam engines, described in Patents Nos. 3400 and 3478 of 1894. In
this case the piston rod of the relay cylinder, at the extreme end of its travel,
after making the cut-off as late as possible, acts upon the spindle of the pass-valve,
opening it, and thus admitting steain continuously to the H.P. cylinder from the
steam-chest, and thus almost continuously to the receiver; the effect is to partially
convert the engine into a simple engine with much increased power. This combined
apparatus is applicable in cases where the variation of load is very great, and
where it is desired to be able to work the engine for short periods at a mean pressure
much exceeding the most economical mean pressure.
It is evident that similar apparatus, applied to a triple-expansion engine, will
partially convert it into a compound engine and that if in a triple-expansion
engine, such apparatus is applied to both the high-pressure and the intermediate
cylinders, the engine may be partially converted into a simple engine if at the
same time an independent steam supply, is opened into the first or high pressure
receiver.
Dated this 20th day of Fabunar 1846
1, MATTHEW HENRY PHINEAS RIALL SANKEY, of Ferry Works, Thames
Ditton, in the County of Surrey, Engineer, do hereby declare the nature of this
invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:-
in cases where it is desired to admit steam, either for starting, or for the

page_text: sake of increased power to the low pressure cylinder or cyliulers of a compound
engine, use relief valves upon the H.P. cylinder or cylinders so arranged as to he
able to lift against the resistance of a spring holding them upon their seats, and
to discharge the water or vapour from the cylinder into a passage connected with
the steam chest. The valves are moved in the usual way by spindles passing
through glands, either by suitable hand-gear, or by the action of the governor
acting either directly or through a relay cylinder, or by electrical means, as by a
solenoid actuated by the increase or decrease of an electrical current.
I apply these valves as an adjunct to the apparatus for automatically varying
the cut off in steam engines, described in Patents Nos. 3400 and 3178 of 1891.
In this case the piston rod of the relay cylinder, at the extreme end of its travel.
after making the cut-off as late as possible, acts upon the spindle of the pass-valve.
opening it, and thus admitting steam continuously to the H.P. cylinder from the
steam-chest, and thus almost continuously to the receiver; the effect is to partially
convert the engine into a simple engine with much increased power. This combined
apparatus is applicable in cases where the variation of load is very great, and where
it is desired to be able to work the engine for short periods at a mean pressure much
exceeding the most economical mean pressure.
It is evident that similar apparatus, applied to a triple-expansion engine, will
partially convert it into a compound engine and that if in a triple-expansion engine,
such apparatus is applied to both the high pressure and the intermedinte
cylinders, the engine may be partially converted into a simple engine, this effect
being increased if at the same time an independent steam supply is opened into
the first or high pressure receiver.
In order that my invention may be fully understood and readily carried into
effect will proceed to describe the drawings annexed.
Figure I in the accompanying drawings is a sectional view of the relief valve
and its chamber, which is attached to the cylinder so that the valve 1 is over a
suitable port communicating with the cylinder clearance. The valve I is kept
against its seat by a spring 2; when acting as a relief valve, it is opened against
this spring by the water pressure on the other side; when acting as a bye-pass, it
is opened by a collar 3 on a spindle 4, passing through a gland. Clearances are
left so that the valve is free to open independently of the spindle, and also to take
a good seat when required. The spindle 4 is here shown actuated through a bell
crank 6 by a rod 5, which may similarly actuate corresponding valves on other
cylinders, and which may be moved as aforesaid either by a hand-lever or equivalent
appliance, as shown in dotted lines in Figure 2, or by the action of the governor,
ncting either directly or through a relay cylinder, ns shewn in the same figure.
The relay cylinder may be controlled by the governor through the mechauism
shown in my Specification No. 3478 of February 17, 1894 or by any other well
derstood means. Whether the action of the governor is direct or indirect, it is
to be understood that such action is secondary to its normal function of controlling
the engine as to speed, whether by throttling the steam supply, or by altering the
point of cut-off.
In Figure 2. 7 is a rod actuated by the movement of the governor balls in the
usual manner, connected directly with the throttle-valve. On an increase of load
the rod 7 moves in the direction of the arrow, and opens the throttle-valve wider.
When the throttle-valve reaches its full open position (but not until then) the
continued movement of the rod opens the controlling valve 8 and allows the steamn
to be exhausted from the end A of the relay cylinder 9. The other end of
the cylinder is in permanent communication with the steam chest, or with
the steam pipe; the piston in the relay cylinder is thus noved in the
direction B, and by the mechanism already described, opens the relief valve,
which is thus constituted a bye-pass continuously admitting steam to the
cylinder so long as the lond upon the engine keeps the governor balls in the
position corresponding with that which retains the controlling valve open.
reduction of the load upon the engine, and consequently slight increase in
On

page_text: speed the rod 7 moves in the direction contrary to that of the arrow, and closes
the controlling valve before commencing to close the throttle valve. The con-
trolling valve is so arranged that when the end A of the relay cylinder is not open
to the exhaust, it is open to the permanent steam supply to the engine. Either
through the other end of the cylinder being in communication with a source of
pressure lower than that of the steam pipe as shewn in the arrangement with full
lines, or through a difference of area on the two sides of the piston as shewn by
dotted lines (if the pressure acting on the two sides is the same) the piston moves
away from A and closes the relief or bye-pass valves. It is evident that the
permanent action of a spring or of a weight might be substituted for that of the
tail rod in the second case.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The arrangement of the relief valve in such manner as to permit of its use
also to admit steam to the cylinder substantially as described.
2. The application of a valve controlled by the governor to admit steam in
such manner as to render a compound engine partially simple, or a tri-compound
engine partially compound, substantially as described.
Dated this Twentieth day of November 1896.