Improvements in High Speed Steam Engines.
Year: 1888

page_text: Date of Application, 2nd Nov., 1883
Complete Specification Left, 31st July, 1889-Accepted, 7th Sept., 1889
PROVISIONAL SPECIFICATION.
Improvements in High Speed Steam Engines.
I, GISBERT KAPP of Stanley Villa Wimbledon in the County of Surrey, Electrical
Engineer do hereby declare the nature of this invention to be as follows:
This Invention relates to improvements in single acting simple or compound,
condensing or non condensing high speed steam engines and has more particular
reference to the method and means for providing a continuous pressure in one
direction between the working surfaces of the cross head pin, crank pin and bearings
so as to avoid knocking and vibration. For this purpose it is necessary that there
should act upon the piston during the return or exhaust stroke a force in the same
direction as the force which propels the piston during the working stroke. This
opposing force must however be of smaller intensity than the force supplied by the
steam during the working stroke and it is not necessary that it should be regulated
with great nicety so long as its intensity is more than sufficient to counteract or
cushion the force arising from the inertia of the moving parts. This cushioning
action can in certain cases be produced by providing such a distribution of steam
as will allow a certain amount of compression, but where engines have to work under
variable conditions it is well known that the compression cannot be regulated so as
to suit all cases and an independent cushioning agent such as a definite volume
of air contained in a separate cylinder is sometimes used. In my improved
type of high speed steam engine I do not rely upon cushioning by compression
of the steain, nor by compression of a volume of air in a separato cylinder, but
I counteract the inertia of the moving parts in and by the hereinafter described
method and means.
In an ordinary simple non-condensing engine I use a cylinder which is closed at
both ends as if it were required for a double acting engine, but I omit one of the
steam passages, so that steam is admitted to and exhausted from one side of the
piston only. The space on the other side of the piston which I call the vacuum side I
connect with the atmosphere by means of a valve opening outwards so that whilst
the engine is at work there will be a partial vacuum in that space. There is thus
during the return stroke an opposing force exerted equal to the product of the area
of the piston and the difference in pressure on both sides. I can provide within
certain limits for a greater or lesser opposing force by varying the clearance space on
the vacuum side of the piston. If the engine is to work in connection with a
condenser the difference of pressure on the two sides of the piston on the upstroke
would be too small to provide sufficient opposing force and in this case I reduce the
area on the working side by employing a trunk piston. 1 may also connect the
opposite or vacuum side of the cylinder to the condenser and dispense with the valve
opening into the atmosphere.
Compound engines I may arrange tandem fashion with the small cylinder behind
the large cylinder and on the same centre line. The two cylinders may form one
continuous space without partition, in which case the large piston is provided with a
trunk which forms the small piston, or there may be a partition wall between the
two cylinders and in this case the two pistons are separately mounted upon the
same rod which passes through the partition by means of a stuffing box. I prefer
the former arrangement on account of greater simplicity but in either arrangement
the low pressure cylinder must be closed in front and the space in front of the piston
must be connected either with the exhaust passage, or if not so connected must be
provided with an air valve opening outwards. In case the two pistons are in one as
above described, the arrangement of an air valve opening into the atmosphere presents
special advantages when the engine is required to work with a variable steam pressure

page_text: and either condensing or non condensing at will and, when, as often happens with
electric light engines on board ship, the steam pressure is highest when the engine is
required to exhaust into the condenser. To provide a fairly constant cushioning force
in such a case I arrange the cut off in both cylinders to take place at about the same
point of the stroke. The cut off may be varied by a governor or by hand, but the
variation must affect both cylinders simultaneously. The exhaust from the small
cylinder I pass into a receiver which may conveniently he made in the form of an
annular chamber surrounding either one or both cylinders, and the steam for the
large cylinder is taken from this receiver. With such an arrangement the steain
pressure in the receiver depends mainly on the proportion between the areas of the
two pistons and the initial steam pressure in the small cylinder, but does not vary very
much when the engine works with different degrees of expansion. The cushioning
force during the return or exhaust stroke is derived from the pressure of the steam
in the receiver against the area of the small piston and that of the exhaust steam
against the annular area of the large piston. When working into the condenser the
force on the large piston is diminished but that on the small piston is increased, whilst
when exhausting into the atmosphere the force on the large piston is increased and
that on the small piston is (on account of the lower initial steam pressure available in
this case) diminished, so that in both cases the cushioning force can be made
approximately the same. To obtain steadiness in running without the use of too heavy
a fly wheel I prefer to put two or three pairs of cylinders side by side but I may also
arrange the cylinders of one pair side by side instead of tandem fashion, and provide
cushioning arrangements as above explained for simple engines. I may also apply my
method of providing a cushioning force to triple expansion engines and the necessary
alterations from the method described for compound engines will readily suggest
themselves to engineers.
In case the initial steam pressure and therefore the receiver pressure is insufficient
to produco the full force required for cushioning I arrange the compound piston in the
shape of three pistons the smallest trunk being the high pressure piston as before, the
intermediate annular area of the second trunk being constantly exposed to the steam
in the receiver and the annular area of the third piston receiving steam from the
receiver during the working stroko only as before. In this case also the front ond of
the low pressure cylinder is closed and provided with an air valve opening outward.
Dated this 2nd day of November A.D. 1888.
WILLIAM E. HEYS,
Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in High Speed Steam Engines.
I, GISBERT KAPP of Stanley Villa Wimbledon in the County of Surrey, Electrical
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 :-
This Invention relates to Improvements in single acting simple or compound, condensing
or non condensing high speed steam engines and has more particular reference to the
method and means for providing a continuous pressure in one direction between the
working surfaces of the cross head pin, crank pin, and bearings, so as to avoid
knocking and vibration. For this purpose it is necessary that there should act upon
the piston during the return or exhaust stroke a force in the same direction as the
force which propels the piston during the working stroke. This opposing force must
however be of smaller intensity than the force supplied by the steam during the
working stroke and it is not necessary that it should be regulated with great nicety so
long as its intensity is more than sufficient to counteract or cushion the force arising
from the inertia of the moving parts. This cushioning action can in certain cases be
produced by providing such a distribution of steam as will allow a certain amount of

page_text: compression but where engines bave to work under variable conditions it is well known
that the compression cannot be regulated so as to suit all cases, and an independent
cushioning agent such as a definite volume of air contained in a separate cylinder is
sometimes used. In my improved type of high speed steam engine I do not rely upon
cushioning by compression of the steam, nor by compression of a volume of air in a
separate cylinder, but I counteract the inertia of the moving parts in and by the
Lereinafter described method and means.
In an ordinary simple non-condensing engine I use a cylinder which is closed at
both ends as if it were required for a double acting engine, but I omit one of the
steain passages, so that steam is admitted to and exhausted from one side of the piston
only. The space on the other side of the piston which I call the vacuum side I
connect with the atmosphere by means of a valve opening outwards, so that while the
engine is at work there will be a partial vacuum in that space. There is thus during
the return stroke an opposing force exerted equal to the product of the area of the
piston and the difference in pressure on both sides. 1 can provide within certain
limits for a greater or lesser opposing force by varying the clearance space on the
vacuum side of the piston. If the engine is to work in connection with à condenser
the difference of pressure on the two sides of the piston on the upstroke would be too
small to provide sufficient opposing force and in this case I reduce the area on the
working side by employing a trunk piston. I may also connect the opposite or vaccum
side of the cylinder to the condenser and dispense with the valve opening into the
atmosphere.
Compound engines 1 may arrange tandem fashion with the small cylinder behind
the large cylinder and on the same centre line. The two cylinders may form one
continuous space without partition, in which case the large piston is provided with a
trunk which forms the small piston, or there may be a partition wall between the two
cylinders, and in this case two pistons are separately mounted upon the same rod which
passes through the partition by means of a stuffing box. I prefer the former arrange-
ment on account of greater simplicity but in either arrangement the low pressure
cylinder must be closed in front and the space in front of the piston must be connected
either with the exhaust passage or, if not so connected, must be provided with an air
valve opening outwards. In case the two pistons are in one as above described, the
arrangement of an air valve opening into the atmosphere presents special advantages
when the engine is required to work with a variable steam pressure and either
condensing or non-condensing at will and when, as often happens with electric light
engines on board ship, the steam pressure is highest when the engine is required to
exhaust into the condenser. To provide a fairly constant cushioning force in such a
case I arrange the cut off in both cylinders to take place at about the same point of
the stroke. The cut off may be varied by the governor or by hand, but the variation
must affect both cylinders simultaneously. The exhaust from the small cylinder 1 pass
into a receiver which may be conveniently made in the form of an annular chamber
surrounding either one or both cylinders, and the steam for the large cylinder is taken
into this receiver. With such an arrangement the steam pressure in the receiver
depends mainly on the proportion between the areas of the two pistons and the initial
steam pressure in the small cylinder, but does not vary very much when the engine
works with various degrees of expansion. The cushioning force during the return or
exhaust stroke is derived from the pressure of the steam in the receiver against the
area of the small piston and that of the exhaust steam against the annular area of the
large piston. When working into the condenser the force on the largo piston is
diminished, but that on the small piston is increased, whilst when exhausting into the
atmosphere the force on the large piston is increased and that on the small piston is
diminished on account of the lower initial steam pressure available in this case, so that
in both cases the cushioning force can be made approximately the same. To obtain
steadiness in running without the use of too heavy a fly wheel I prefer to put two or
three pairs of cylinders side by side but I may also arrange the cylinders of one pair
side by side instead of tandem fashion, and provide cushioning arrangements as
hereinbefore explained for simple engines. I may also apply my method of providing

page_text: a cushioning force to triple expansion engines and the necessary alterations from
the method described for compound ongines will readily suggest themselves to
engineers.
In case the initial steam pressure and therefore the receiver pressure is not
sufficient to produce the full force required for cushioning in the previously described
arrangement of compound engine, I arrange the compound engine in the shape of
three pistons the smallest trunk being the high pressure piston as before, the inter-
mediate annular area of the second trunk being constantly exposed to the steam in
the receiver and the annular area of the third piston receiving steam from the receiver
during the working stroke only as before. In this case also the front end of the low
pressure cylinder is closed and provided with an air valve opening outwards or with a
passage leading into the exhaust chamber.
The appended sheet of drawings illustrates the application of my Improvements.
In Fig. 1 the steam cylinder C is provided at the top with a steam passage a a¹ leading
from the valve chest, and at the bottom with a valve V opening outwards. The steam
enters at S and is distributed by the slide valve A to the top of the piston H, the
exhaust taking place through the orifice E. Fig. 2 illustrates a modified arrangement
when the piston H is provided with a trunk T for the purpose of increasing the
downward pressure due to the partial vacuum in the cylinder C under the piston H.
This arrangement I adopt when the engine is required to exhaust into the condenser.
In this case the vacuum on the top of the piston H in Fig. 1 on the upstroke would
balance the vacuum under the piston and no downward pressure would be obtained.
By shaping the piston as shown in Fig. 2 I obtain a downward pressure due to the
pressure of the atmosphere upon the trunk T. Instead of employing the valve V,
may provide a passage P' between the lower part of the cylinder and the exhaust
f
chamber.
In Fig. 3 I illustrate the application of my Improvements to a compound tandem
engine. Cand Caro respectively the high and low pressure cylinders containing the
pistons H and L mounted upon the same piston rod. The two valves A and B are
also mounted upon a rod common to both and move simultaneously. The steam
ports a a, b b and the valves are so arranged that the cut off in both cylinders takes
place simultaneously, the point of cut off being varied according to the load of the
engine either by hand or by any form of automatic governor. The steam pressuro in
the receiver R during the upward or return stroke acts against the upper face of the
piston H and produces the downward pressure required to counterbalance the inertia
of the moving parts. The absolute amount of this pressure is not greatly altered by
changes in the degree of expansion so that at all loads the engine is capable of
working without knocking. I arrange a passage Q between the lower parts of the
high and low pressure cylinders and I provide a valve V opening outwards so that
during the return or up stroke a partial vacuum is formed under both pistons. If
the engine is required to work always with the same steam pressure and this
pressure be high enough, 1 may omit the valve V and provide a passage P into the
exhaust chamber.
Fig. 4 shews the application of my Improvements to a compound engine fitted with
a high pressure trunk piston H. The bottom end of the low pressure cylinder is
closed and provided with a channel d leading to a valve V opening outward or I may
omit this valve and employ a passage P leading to the exhaust chamber. In Fig. 3
there is a partition between the two cylinders but in Fig. 4 this partition is omitted, as
is also the passage Q. The steam is distributed by a piston valve A B, the part A
controlling the admission of steam through port a, and channel a¹ to the high pressure
cylinder, and the part B controlling the admission of the steam from the receiver to
port and channel. The high pressure steam enters through S and surrounds the
upper neck of the valve at S¹. "When the valve moves downwards steam is admitted
to the top of the piston H and simultaneously the steam in the receiver is admitted
through passages to the annular face of piston L. When the two pistons have 5
advanced through a certain part of the stroke the valve moves upwards and cuts off
the steam supply to both cylinders, and the rest of the stroke is performed expansively.

page_text: During the return stroke the valve is moved further up, establishing communication
between the high pressure cylinder and the receiver R on the one hand and between
the low pressure cylinder and the exhaust E by way of the ports E¹ on the other hand.
The steam in the high pressure cylinder is forced into the receiver R and exerts a
downward pressure upon the piston H which increases as the piston approaches the top
of its return or up stroke. The increase of pressure depends upon the ratio of
cubical capacity between the high pressure cylinder and receiver and I find in practice
that good results are obtained if the receiver has from equal to twice the capacity of
the high pressure cylinder.
The arrangement shewn in Fig. 4 is particulary applicable for an engine which has
to work under either of the following conditions viz. -(1) High initial steam
pressure, exhausting into the condenser; (2) Lower initial steam pressure exhausting
into the atmosphere. If either of these conditions is imposed upon the engine I omnit
the passage P and adopt the valve V so that there may be the same degree of vacuum
under the piston L in all cases. When the steam pressure is low the receiver pressure
is also low and the downward pressure on piston H may not be sufficient by itself to
produce complete cushioning. But in this case the annular area of piston Lis
exposed to atmospheric pressure during the up stroke, which added to the receiver
pressure on top of piston H is sufficient to produce complete cushioning. If the
steam pressure is high and the engine exhausts into the condenser then there is no
sensible pressure on the annular area of piston L during the up stroke but as the
receiver pressure coming on top of piston H is now also high, this pressure alone is
sufficient to produce complete cushioning.
It may happen that an engine be required to work with a comparatively low initial
steam pressure and exhaust into a condenser and then the cushioning pressure
obtainable from the small piston only may be insufficient to overcome the inertia of
the moving parts at the end of the up stroke. In this case I prefer to arrange the
engine as shewn in Fig. 5.
The low pressure piston L is separated from the high pressure piston H by an inter-
mediate piston I the top of which is constantly exposed to the steam pressure in the
receiver R by means of a passage c.
The valves A and B are arranged so that the cut
off for the two cylinders is simultaneous at all loads. The bottom of the low pressure
cylinder communicates by opening d and channel P with the exhaust chamber E.
During the working stroke the steam in the receiver R acting upon the intermediato
piston I expands even after valve B has closed the inlet to the low pressure cylinder
and the receiver pressure continues to diminish to the end of the stroke. During the
return stroke the piston H and the piston I both force the steam back into the receiver
and the pressure increases to the end of the return stroke. By this arrangement I
ensure that the greatest cushioning force (due to the receiver pressure on pistons H
and I) takes place at the end of the stroke, that is to say at the moment when it is
most required. I prefer to surround the high pressure cylinder with a steam jacket
and have shewn steam jackets at F in Figs. 3, 4 and 5.
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) In a single acting non condensing steam engine the construction and arrange-
ment of a steam cylinder closed at both ends as shewn at Fig. 1, provided with the
usual steam port at one end and at the other end with a valve V opening outwards or
a passage to a space in which a vacuum is maintained; substantially as and for the
purpose herein before described and illustrated.
(2) In a single acting condensing or non condensing steam engine the combination
of a steam cylinder with a trunk piston constructed and arranged as shewn in Fig. 2
the cylinder being provided at its front end with a valve V opening outwards or a
passage leading to a space in which a vacuum is maintained substantially as and for
the purpose hereinbefore described and as illustrated by the drawings.

page_text: (3) In a single acting tandem compound engine; the combination and arrangement
with a low pressure cylinder closed at the front end and having a passage to the front
end of the high pressure cylinder as shown in Fig. 3, of a valve V opening outwards
(or a passage connecting the front end with a condenser), and a system of steam
distribution valves and ports so arranged as to ensure an equal and simultaneous
cut off in both cylinders substantially as and for the purpose hereinbefore
described.
(4) A single acting compound engine constructed arranged and operating substan-
tially as herein before described with reference to Fig. 4 of the accompanying
drawings.
(5) In a single acting tandem compound engine the combination with a low pressure
cylinder closed in front as shewn in Fig. 5 and provided with a passage P leading to
the exhaust (or a valve opening outwards into the atmosphere) of an intermediate
cylinder and piston constantly opposed to the pressure of the steam in the receiver R
substantially as and for the purpose hereinbefore described.
Dated this 25th day of July A.D. 1889
WILLIAM E. HEYS,
Agent for the Applicant.