Improvements in Steam and other Fluid-pressure Engines.
Year: 1890

page_text: Date of Application, 24th Oct., 1890
Complete Specification Left, 24th July, 1891-Accepted, 5th Sept., 1891
PROVISIONAL SPECIFICATION.
Improvements in Steam and other Fluid-pressure Engines.
I, JOHN TAYLOR EWEN of Millbank House, Forfar, in the County of Forfar,
North Britain, Engineer, do hereby declare the nature of this invention to be as
follows:-
The object of my invention is to simplify the construction of high-pressure
engines with two or three or more cylinders, and of compound engines with
expansion in two or three or more cylinders, by reducing the number of their
working parts and making them more compact and rigid, and by securing a
quicker cut-off and a better distribution of steam to the cylinders than is usual
with the present arrangement of valve-gears.
This I do by dispensing altogether with one or more of the eccentrics or other
gear generally used to actuate the steam-distributing valves, and driving each
valve whose eccentric or other gear is thus dispensed with, direct from the
cross-head or other similarly moving part of one of the other cylinders in such
a manner as will shortly be described.
I will now describe one modification of my invention as applied to a three-
cylinder inverted compound engine working on three separate cranks; in which
each of the valves is driven direct from the cross-head or other similarly moving
part of one of the other cylinders.
The cranks are supposed to be placed at equal angles to each other and to
he arranged in the following sequence :-High-pressure, mean-pressure, low-
pressure. I wish it to be understood however that the angles between the cranks
need not be equal, and that their sequence as given above may be varied.
In this particular arrangement, I rigidly connect the low-pressure valve to
the cross-head or other similarly moving part of the mean-pressure cylinder,
and as the mean-pressure crank is 120° in advance of the low-pressure crank,
this arrangement will give a similar motion to the low-pressure valve as would
be given by an eccentric placed 120° in advance of the crank.
In the same manner the mean-pressure valve is driven direct from the cross-
head or other similarly moving part of the high-pressure cylinder, and the high-
pressure valve from the cross-head or other similarly moving part of the
low-pressure cylinder.
In another modification of my invention I use one eccentric or other gear to
actuate the valve of one of the cylinders of any three-cylinder engine with
three cranks, while the remaining valves are driven direct from cross-heads or
other similarly moving parts as already described.
I wish it to be understood further that I intend to make the cylinders of
three-cylinder engines sometimes with all three strokes equal, sometimes with
only two of the strokes equal, and sometimes with all three strokes different, as
may be found suitable for the special working conditions of the engines. In a
similar way I intend to vary the strokes of engines having more than three
cylinders.
;
In two-cylinder engines I place the cranks at any suitable angle to one
another, and actuate the valve of one cylinder by means of an eccentric or
other suitable gear, while the valve of the other cylinder will be actuated
direct from the cross-head or other similarly moving part of the first-mentioned
cylinder.
In this arrangement again I intend to make both cylinders of the two-cylinder
engines sometimes with equal strokes and sometimes with unequal strokes, as
may be found most suitable for the special working conditions of the engines.

page_text: I do not of course bind myself to the exact details as here stated, as it will
be seen that these may be considerably varied without in any way altering the
nature or purpose
invention.
D
71
of my
00
if Antibion 1900.
COMPLETE SPECIFICATION.
Improvements in Steam and other Fluid-pressure Engines.
I, JOHN TAYLOR EWEN, Engineer, of Millbank House, Forfar, Scotland, 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:
This invention for improvements in steam and other fluid pressure engines has
for its object to simplify the construction of high pressure engines with two, three,
or more cylinders, and of compound engines with expansion in two three or more
cylinders by reducing the number of their working parts and making them more
compact and rigid and by securing a quicker cut off and a better distribution of
steam to the cylinders than is usual with the present arrangement of valve gears.
In an engine constructed according to this invention one or more of the eccentrics.
or other gear generally used to actuate the steam distributing valves are dispensed
with and each valve whose eccentric or other gear is thus dispensed with is driven
direct from the crosshead or other similarly moving part of one of the other
cylinders..
In one arrangement of three-cylinder inverted compound engine working on to
three separate cranks, each of the valves is driven direct from the crosshead or
other similarly moving part of one of the other cylinders. The cranks are placed at
equal angles to each other and are arranged in the following sequence: High
pressure, mean pressure, low pressure. The low pressure valve is rigidly connected
to the crosshead or other similarly moving part of the mean-pressure cylinder, and
as the mean-pressure crank is 120 degrees in advance of the low pressure crank a
similar motion is given to the low pressure valve as would be given by an eccentric
placed 120 degrees in advance of the crank. In the same manner the mean
pressure valve is driven direct from the crosshead or other similarly moving part
of the high pressure cylinder and the high pressure valve from the crosshead or
other similarly moving part of the low pressure cylinder.
In another arrangement of three-cylinder engine working on to three separate
cranks, one eccentric or other gear actuates the valve of one of the cylinders while
the remaining valves are driven direct from crossheads or other similarly moving
parts as already described.
In one arrangement of two cylinder engine, the cranks are arranged at any
suitable angle to one another and the valve of one cylinder actuated by means of
an eccentric or other suitable gear while the valve of the other cylinder will be
actuated direct from the crosshead or other similarly moving part of the first
mentioned cylinder.
In the accompanying two sheets of illustrative drawings
Fig. 1 is a sectional elevation of a three cylinder inverted compound engine
working on to three separate cranks constructed according to this invention:
Fig. 2 is an elevation of a two-cylinder inverted simple engine constructed
according to this invention, and
Fig. 3 is a plan of the same.
Referring to Fig. 1, the pistons a a, ba, c a, of the three cylinders a, b, c are
connected to three separate cranks a b, bb, e b, on the crank shaft. The valve a c
of the cylinder a is driven from. an eccentric a d on the engine shaft. The steam
is admitted to the valve chest a at the centre of the valve, and exhausts at the
ends of the valve and by the passages af and bf to the ends of the valve cheste

page_text: of the cylinder b. The valve be is driven directly from the crosshead of the
cylinder a by means of the bracket b h. The steam exhausts from the cylinder b
through the centre of the valve bc and by the passages bg and cf to the ends of
the valve chest ce of the cylinder c. The valve c is driven directly from the
crosshead of the cylinder 6 by means of the bracket ch. The cylinder c exhausts
by the centre of the valve c c and passage c g.
In the two cylinder simple engine shown in Figs. 2 and 3, the valve of the
cylinder d works in the valve chest da and is driven from the bracket db on the
crosshead of the cylinder e; and the valve of the cylinder e works in the valve
chest e a and is driven from the bracket eb on the crosshead of the cylinder d.
This arrangement is suitable for winch or other reversing engines and for engines
which usually work up to their full power.
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 :-
1. In fluid pressure engines having more than one cylinder, actuating the
distributing valve of one cylinder directly from the crosshead of another cylinder
without the intervention of levers links or the like substantially as described.
2. In fluid pressure engines having more than one cylinder, actuating the
distributing valve of one or more of the cylinders directly from the crosshead of
another cylinder whilst the remaining valves are actuated in the ordinary manner
substantially as described.
3. The arrangement for actuating the distributing valves of fluid pressure engines
having two or more cylinders substantially as described with reference to the
drawings.
Dated this 24th day of July 1891.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.