Improvements in Compound Steam Engines.
Year: 1894

page_text: Date of Application, 20th Apr., 1894
Complete Specification Left, 21st Jan., 1895-Accepted, 23rd Feb., 1895
PROVISIONAL SPECIFICATION.
Improvements in Compound Steam Engines.
Communicated by FREDERICK FURSE, of Villa Schlaepfer, Capo di Monte,
Naples, in the Kingdom of Italy, Engineer.
I MORTIMER WILLIAM ASH of 38 Trebovir Road Kensington in the County of
Middlesex Engineer do hereby declare the nature of this invention to be as
follows:-
The object of this invention is to provide compound steam engines that will be
lighter more compact and efficient as well as cheaper than those at present in use
whereby they will be suitable for and capable of being used on all occasions and
for all purposes but will be more especially applicable and useful as high-speed
engines.
To carry out this object say in a simple compound engine a cylinder is made in
any ordinary and suitable manner jacketed or clothed or otherwise treated as may
be desired but this cylinder is so constructed and fitted internally that the upper
half or part thereof is of a much smaller diameter than the lower half or part
thereof the difference between the areas of these two halves or parts of the cylinder
being that which is required ordinarily between the areas of an high pressure
cylinder and a low pressure cylinder or these areas may be of other convenient
proportions. A piston is made for this cylinder the upper and diametrically smaller
part of which fits the upper and diametrically smaller part of the cylinder and is
of about the same length as this part so that at the bottom of the stroke of the
piston this upper part of the piston does not leave the upper part of the cylinder
but is still properly tight therein the packing ring or other appliances being fitted
near the upper end of this part of the piston. The lower and diametrically larger
part of the piston fits the lower and diametrically larger part of the cylinder and
it may be made and formed and packed in any manner as may be desirable.
The rod of this piston passes out of the cylinder at its larger end in any usual
manner.
The valve chest of this cylinder is made in any ordinary manner and a passage
is provided from the upper part of the same to the top end of the cylinder and
another passage is provided from the lower part of the same to the bottom end of
the cylinder while the steam can be admitted thereinto about the middle of the
same and is exhausted therefrom at its lower part and these passages between the
valve chest and the cylinder and the ports thereof can be made and formed in any
ordinary manner and of any desirable style and shape.
A piston valve is preferably used in this valve chest and it can be so made and
formed and such passages are created therein that in its uppermost position com-
munication is opened between the steam inlet and the top end of the cylinder above
the piston and then as the valve travels downwards this communication is gradually
closed until when and after it is entirely closed communication is gradually opened
through the valve between the top end of the cylinder above the piston and the
bottom end of the cylinder below the piston and when the valve is in its lowest
position this communication is fully opened and then the valve commences to travel
upwards gradually closing this communication until as it reaches its uppermost
position communication is opened between the bottom end of the cylinder below the
piston and the steam exhaust or vice versa.

page_text: The action of this apparatus is as follows. The steam passes first to the top end
of the cylinder above the diametrically smaller part of the piston where it acts as
high pressure steam and in this part of the cylinder there need be no packing gland
as the piston rod need not pass out of this end of the cylinder and this is an
advantage. When the piston has thus been driven to the bottom of its stroke the
steam can pass out of this diametrically smaller part of the cylinder through the
valve to the bottom end of the cylinder below the diametrically larger part of
the piston and in this diametrically larger part of the cylinder it can expand and
act as low pressure steam until it has driven the piston back to the top of its stroke
when it passes to the exhaust and fresh steam is admitted to the top end of the
cylinder and so on.
The space in the diametrically larger part of the cylinder above the diametrically
larger part of the piston can be in communication with the exhaust or with the
condenser or otherwise to ensure that there shall be no back pressure.
In a triple expansion engine another cylinder of a still larger diameter can be
arranged below this cylinder in which is a corresponding piston on the same rod
and the steam on leaving the diametrically larger part of the cylinder aforesaid can
be admitted to this still larger cylinder alternately above and below the piston
therein in any usual or other manner and by and through any ordinary and
suitable means and appliances.
In a quadruple expansion engine the aforesaid cylinder with two diameters with
its appropriate piston and valve would be duplicated care being taken that the
proportionate diameters and areas of these two cylinders necessary for such
expansion are duly maintained and the second cylinder may be placed below or at
the side of the first cylinder or elsewhere in respect of the same as may be desired
in each case proper passages being formed to lead the steam from the bottom end
of the smaller cylinder to the top end of the larger cylinder.
I have thus described this engine as arranged in the ordinary inverted vertical
manner but it can obviously also be arranged in any other position as may be
desired.
Dated this 20th day of April 1894.
HART & Co..
186, Fleet Street, London, E.C., Agents.
Communicated by FREDERICK FURSE, of Villa Schlaepfer, Capo di Monte,
Naples, in the Kingdom of Italy, Engineer.
1 MORTIMER WILLIAM ASH of 38 Trebovir Road Kensington in the County
of Middlesex Engineer do hereby declare the nature of this invention and in what
inanner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
The object of this invention is to provide compound steam engines that will be
or may be lighter and more compact and efficient as well as cheaper than are most
of those at present in use whereby they will be suitable for and capable of being
used on all or most occasions and for all or most purposes but will be more especially
applicable and useful as high-speed engines.
In order the more clearly to explain this invention and in what manner the same
is to be performed I refer to the accompanying drawing wherein I have shewn a
vertical section of this compound steam engine according to one extremely
convenient style and manner of construction.

page_text: A cylinder A is made in any ordinary and suitable manner being jacketed or
clothed or otherwise treated as is customary and as may be desirable externally
while internally this cylinder A is so constructed or fitted in any ordinary and
appropriate manner that the upper half or part thereof is of a much smaller
diameter than the lower half or part thereof the difference between the areas of
these two halves or parts of this cylinder A being that or about that which is
ordinarily required between the areas of an high pressure cylinder and a low
pressure cylinder in an ordinary compound engine or these areas may be of other
convenient proportions as may be appropriate in each particular case. I shew in
the drawing an extremely convenient manner of effecting this object although I do
in nowise limit myself thereto. According to this manner the cylinder A is made
of the same diameter throughout and in the upper part thereof is fitted and
arranged an annular casing B of the desired style and size and depth and the
surface of the inner periphery of this casing B forms the cylinder of the smaller
diameter which I will call C while the cylinder of the larger diameter or that is to
say the lower part of the cylinder A below the casing B I will call D. A piston E is
made for this cylinder A so fitted and arranged as is hereinbefore described which
piston E is of corresponding diameters and this piston E is most conveniently
formed and constructed as is shewn in the drawing although I do in nowise limit
myself thereto. According to this manner the upper and diametrically smaller
piston F is connected by a trunk with the lower and diametrically larger piston G
the piston rod H passing through both the pistons F and G and the trunk and the
stroke of this piston E is so regulated and is of such a length that at the top
thereof the piston G is in close proximity to the lower part or bottom of the
casing B if any or to the lower end of the cylinder C while at the bottom thereof
the piston F has not left but is still in this cylinder C and these pistons F and G
can be packed in any ordinary or other desirable manner. The piston rod H passes.
out or may pass out of the cylinder A at, its lower and larger end being there
packed and otherwise treated as is customary.
As is hereinbefore stated I consider that the style and manner of construction and
fitment shewn in the drawing are extremely convenient but as is indeed sufficiently
obvious all these parts that is to say the cylinder A consisting of and being the
two cylinders C and D of differing diameters and the piston E also consisting of
and being the two pistons F and G of differing diameters can be formed an
constructed and fitted together with the piston rod H in any manner and after
any style that may be customary and may be appropriate or desirable in each
particular case.
The valve chest K of this cylinder A is also made in any ordinary and suitable
manner and a passage L is provided leading from the upper part of the same to
the top end of the cylinder C passing through the casing B if any and another
passage M is provided leading from the lower part of the same to the bottom end
of the cylinder D while the steam is admitted thereinto through the port N at or
about the middle of the same and is exhausted therefrom through the port P at the
lower part of the same which passages L and M and ports N and P can be made
and formed in any customary manner and of any appropriate or desirable size and
shape and style.
A piston valve R is most conveniently used in this valve chest K which piston
valve R is also made in any ordinary and suitable manner and therein is formed a
passage or recess T at or about the middle of the length of the same and also
another passage V which issues from this piston valve R both above and below
the passage T which passages T and V likewise can be made and formed in
any customary manner and of any appropriate or desirable size aud shape and
style.
When another kind of valve is used in the valve chest as for example an ordinary
slide valve the same two passages would be formed therein but the valve would
require to be pressed down in any customary manner on the slide face of the valve
chest as in all cases under the arrangements herein contemplated the steam is

page_text: admitted under or inside the valve or between the same and the cylinder and is
exhausted from outside or over the same.
The action and cycle of operations of and in this compound steam engine herein-
before described are as follows.
When all the parts are in the positions shewn in the drawing the piston E is at
or very near the top of its stroke and the valve R is also approaching the top of
its stroke and the passage L is being uncovered. The steam entering the port N
passes through the passages T and I to the top end of the cylinder C above the
piston F where it acts as high pressure steam and forces this piston downwards.
As the piston F descends so does the valve R gradually closing the passage L and
cutting off the continuity of the same with the passage T until by the time the
piston F has descended to the bottom of its stroke the passage L is in communi-
cation with the passage V which also is in communication with the passage M and
the steam from the cylinder C passes through these passages L and V and M to the
bottom end of the cylinder D below the piston G where expanding it acts as low
pressure steam and forces this piston G upwards. As the piston G ascends so does
the valve R gradually closing the passages Land M and cutting off the continuity
of the same with the passage V until by the time the piston G has ascended to the
top of its stroke the passage M is uncovered and the steam from the cylinder D
can enter the valve chest K and is exhausted therefrom through the port P while
at the same time steam entering the port N can pass through the passages T and L
to the top end of the cylinder C above the piston F and the aforesaid cycle of
operations is repeated and so on.
Thus in a very simple and efficient manner and by and through very simple
and effective means and appliances steam is introduced into the diametrically
smaller end of a compound cylinder above a compound piston to act as high
pressure steam and then is passed into the diametrically larger end of this
compound cylinder below this compound piston to expand and act as low pressure
steam.
If and when it may be necessary or convenient so to do the space in the
cylinder D above the piston G and between the same and the piston F can be
connected by a pipe or otherwise be in communication with the exhaust or with the
condenser or other suitable part to ensure that there shall be no back pressure
against either of these pistons F and G and more especially against the piston G.
The top of the cylinder A is preferably formed as shewn in the drawing and is
fitted with a cover W as the piston rod H need not pass out of this end of the
cylinder A thereby dispensing with any packing gland exposed to high pressure
steam which obviously is a great advantage.
I have thus described this compound engine and I have shewn the same in the
accompanying drawing as arranged in the ordinary inverted vertical position but it
is sufficiently obvious that I do not limit myself to such position for it may also
plainly be arranged in any other position both in respect of itself and of the work
that it performs as may be desired in each particular case but the action of the
same and the cycle of operations therein as herein before described would always
obtain and be performed.
Having now particularly described and ascertained the nature of this said inven-
tion and in what manner the same is to be performed declare that what I
claim is
1. In a steam engine a compound cylinder A being two cylinders C and D of
differing diameters and a compound piston E being two pistons F and G of differing
diameters in such cylinder A in combination with a valve chest K.passages L and M
between the same and the cylinder A a valve R in the valve chest K and passages T
and V in such valve R steam being admitted under or inside the valve R and
exhausted from outside or over the valve R the whole being arranged and
combined and operating substantially as and for the purpose 'hereinbefore described
and declared.

page_text: 2. The compound steam engine substantially as hereinbefore described and shown
in the accompanying drawing.
Dated this 21st day of January 1895
HART & Co.,
186, Fleet Street, London, E.C., Agenta.