Improvements in Compound Steam Engines.
Year: 1888

page_text: Date of Application, 9th May, 1888
Complete Specification Left, 9th Feb., 1889
Complete Specification Accepted, 16th Mar., 1889
Improvements in Compound Steam Engines.
ROBERT MUDGEMARCHANT of 26 Wellington Street, Upper Street, Islington,
London N., Civil Engineer, and OTHO GILES ABBOTT of 6 Clarendon Road,
Kimberley Road, Stockwell, London S.W., Gentleman do hereby declare the nature
of this invention to be as follows
1 The construction of interior cylinders which shall be turned and finished for
the working of an interior piston in the ordinary manner-the barrel of such cylinder
being extended beyond its bottom end so as to allow of the half or other portion of
the exterior length of such cylinder with its extended complement (for length) being
turned & finished into one surface applicable for the working on such surface of the
interior side of an annular piston which shall so work on the external surface or skin
of such interior cylinder & be supplied with ordinary or other attachments to the
working shaft of the Engine.
2-The construction of external cylinders of such larger diameter as shall leave
the required annular space between the outside of the interior cylinder & the turned
and finished interior of these larger and exterior cylinders, against which the exterior
side of the annular piston works.
3-The construction of holes or other sufficient passages through the interior
cylinder at the half or other proportion of the stroke of its ordinary piston & their
communication with one end of the annular space or cylinder.
4-The construction of an annular piston which shall be so constructed & so operated
on by springs as to provide steam tight action to both the interior & exterior of such
annular space & piston.
5-The delivery & use & expansion of the high pressure steam into & from the
interior cylinder through the passages (3) & into the outer cylinder for the purpose of
effecting one stroke of the annular piston.
6-The delivery & application of an alternate charge of high pressure steam for
expansion use at the opposite end of the annular piston to the purpose of effecting the
other stroke of such annular viston.

page_text: 7-During such "other" stroke of the annular piston the return passage of all that
high pressure steam which had been delivered and expanded and used from the
interior cylinder & through the passages (3) back into such interior cylinder &
thence through the piston rod end of such interior cylinder to a surface condenser
in connection with that end thereof.
"
8-During the " one "stroke of the annular piston the passage & delivery of all
the expanded steam of the high pressure charge which had effected the "other
stroke of such annular piston & through pumps & without condensation to the
Boiler.
9 The piston rod end of the interior cylinder will be connected with a surface
condenser & the opposite end of the outer or annular cylinder will be connected
through pumps with the Boiler.
10 The construction of piston check valves for the purpose of securing effective
high pressure application without leakage.
11 The provision for reversing the Engine & the general combination & con-
struction for effecting such application.
12-The invention herein before described is applicable to the purpose of effecting
Engine power for any requirement & the machinery therefor can be varied to suit
the particular application.
Dated this 9th day of May 1888.

page_text: Improvements in Compound Steam Engines.
We ROBERT MUDGEMARCHANT, of 26 Wellington Street, Upper Street Islington,
London, N., Civil Engineer, and OTHO GILES ABBOTT, of 6 Clarendon Road,
Kimberley Road, Stockwell, London, S.W., Gentleman, 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 :-
1. The construction of interior, or otherwise comparatively small, cylinders for
the working of an interior or otherwise comparatively small, piston in the ordinary
manner, the barrel of such cylinder being either extended beyond its bottom end
so as to allow of the half or other portion of the exterior length of such cylinder
with its extended complement (for length) being turned and finished into one surface
applicable for the working on such surface of the interior side of an annular piston
which shall so work on the external surface or skin of such interior cylinder; or be
so constructed and connected with a larger cylinder, as shown in the modification,
for effecting the described action and for attachment to the working shaft of the
engine.
2. The construction of external, or otherwise comparatively large, cylinders which
shall either leave the required annular space between the outside of the interior
cylinder and the interior of such larger, and exterior, cylinders for working an annular
piston; or, according to the modification shown, be adapted to the purpose of effecting
the described action from the smaller to the larger cylinder and "rice versa.
وو
3. The construction of holes, or other sufficient passage or passages, from the
interior or otherwise comparatively sinall, cylinders at the half, or other proportion,
of the stroke of the piston; and their communication with one end of the annular
space or larger cylinder.
4. The construction of an annular piston which shall be so constructed and so
operated on by springs as to provide steam tight action to both the interior and
exterior of such annular space and piston.
5. The delivery, and use, and expansion, of the high pressure steam into and from
the interior, or otherwise small cylinder, through the sufficient. passsage or passages, (3)
and into the outer, or comparatively large, cylinder for the purpose of effecting one
stroke of its annular or other piston.
6. The delivery and application of an alternate charge of high pressure steam, for
expansive use, at the opposite end of the annular, or otherwise larger, piston for the
purpose of effecting the other stroke of such piston.
7. During such "other" stroke of the annular, or otherwise larger, piston the
return passage of all that high pressure steam which had been delivered, and
expanded, and used, from the interior, or otherwise smaller, cylinder; and through
the passages (3) back into such cylinder, and thence through the piston rod end of
such cylinder to a surface condenser in connection with that end thereof.

page_text: "
8. During the " one stroke of the annular, or otherwise larger, piston the
passage and delivery of all the expanded steam of the high pressure charge, which
had effected the
"
other stroke of such larger piston, and through pumps and
without condensation to the boiler.
9. The piston rod, or front end, of the interior, or otherwise smaller, cylinder will
be connected with a surface condenser ; and the opposite end of the outer, or other-
wise larger cylinder, will be connected through pumps with the boiler.
10. The construction of piston check valves for the purpose of securing effective
high pressure action without leakage.
11. The provision for reversing the engine, and. the general combination and con-
struction for effecting such application.
12. The invention hereinbefore described is applicable to the purpose of effecting
engine power for any requirement; and the machinery therefor can be varied to suit
the particular application.
The annexed drawings will serve to illustrate the invention.
Figure 1, is a side elevation of the engine.
Fig. 2, is a plan of the engine.
Fig. 3 is a section through the high and low pressure cylinders showing the
pistons in position.
Fig. 4 is a cross-section through the cylinders showing the annular piston with
its top plate removed and with the adjusting spring to each section in position.
Fig. 5 is a modified construction for a vertical engine applicable to the purpose of.
effecting the same steam application.
Fig. 6 is a side elevation of the same.
Fig. 7 is a plan of the same.
Fig. 8-is a vertical section through the cylinders and valve boxes showing the
pistons in their position for the same.
Fig. 9-is the disc reversing gear as shewn in the above constructions.
In carrying our invention into practice we construct the comparatively small
cylinder a, to work in connection with the larger cylinder b, as shown in either form
(Figs. 3 and 8). High pressure steam is admitted through the port c into cylinder a
to work in connection with the larger cylinder b, as shewn in either form (Figs. 3 and 8).
High pressure steam is also admitted through the port c into cylinder a, forcing the
piston d downwards and, when the piston d in its passage through the cylinder opens
the porte; the high pressure steam being cut off by the piston valve f; the charge
is expanded on the larger piston d¹, forcing that piston upwards (the crank of the
larger cylinder being set at right angles ahead of the small cylinder crank) to the
end of its stroke, at which point the smaller piston d has returned to the port e and
opens the same on the opposite side of the piston d, thus giving free exhaust to the
expanded charge of the steam from the cylinder b, through the outlet at the lower
end of the cylinder a. For the return action of the larger piston d' the high pressure
steam is admitted by the piston valve f¹ through the port c¹ and is cut off by the
said valve at any required portion of its stroke. A similar piston valve f is used
on the back side of the cylinder (as shown in Figs. 2 and 7) for the purpose of
delivering, on the return stroke, such expanded charge to the pump / through the
valve the piston of that pump being driven forward by the charge so delivered
from the cylinder b. The set of the pump crank for this action is opposite to the
crank for the cylinder ; so that, when the delivery from this side of the piston d' of
the cylinder is being effected, the pump piston travels forward to receive the charge;
and, on its return stroke, the charge is again forced forward through the valve h² into
the front end of the barrel; the capacity of which is reduced to the required propor-
tion for the last pump by means of the sleeve i, and from this last pump it is forced
forward through the valve into the boiler. That portion of the steam which is
admitted into the small cylinder a, and, after its use on the larger piston d' is
already shewn to be exhausted through outlet g,-is passed through that outlet to a
surface condenser and is returned as water to the pump h, by means of the small pumpj,
through the pipe and valve *; and from the pump it is returned with the steam to
;

page_text: the boiler. With every revolution of the engine a small supply of air is delivered
into the pump h, by means of the small pump, and through the pipe and valve j³,
for the purpose of forming a spring in the pump clearance.
::
It will be observed (from the description of the action as above stated) that all the
steam supplied to the small cylinder a, and expanded on one side of the larger piston d¹
is condensed; and that all the steam supplied to the larger cylinder b, on the opposite
side of its piston, remains uncondensed and is passed forward to the pump h without
the extraction of its latent heat, and thence, with the condensed portion, is delivered to
the boiler. The construction of the annular piston is shown in Figs. 3 and 4. The
reversing of the engine is effected by the means shewn for disconnecting the crank,
or disc, 7, of the larger cylinder b. from the crank, or disc, l, of the smaller
cylinder ; at either end of the stroke, determined on, the engine is pulled up
by an auxiliary charge of steam from the "three-way valve k, and, after the steam
has been shut off from the cylinders by the starting valve -the said auxiliary
charge pulling the engine up before the crank arrives at the dead centre, and
at such point the discs are disconnected from each other by means of the spring
pawl (shewn in Fig. 9), which is forced forward by means of the sliding
bolt 1, connected to the hand lever ; and, whilst it is in such position, the auxiliary
steam charge is admitted to the cylinder b, only for the purpose of driving its piston, d¹,
in the opposite direction one-half revolution; the other piston, d, remaining stationary
for such half revolution; at the end of which the opposite spring pawl will have
slipped past the projecting quadrant of disc ', which lays in the recess of disc 1, and
will connect the 2 discs automatically for their travel in the opposite direction. The
eccentrics working the valves, f, f and f, are loose on the shaft, and are driven by
stops cut to the required angles for both ways of running, so that these eccentrics
follow automatically the reversed action of the engine. The pump m withdraws the
air from the surface condenser and maintains a vacuum therein.
Having now particularly described and ascertained the nature of our said Inven-
tion, and in what manner the same is to be performed, we declare that what we
claim, in respect of "Improvements in compound steam engines," is :—
1. The application and method of so using the steam that one portion shall be con"
densed, in a surface condenser, and retained as water with the ordinary vacuum action,
obtained by such condensation of a portion of the steam only; whilst the other
portion is returned to the boiler, in combination therewith, and without the extraction
of its latent heat; so that the whole charge is returned partly as steam and
partly as water in a continuous circuit; by which means a great saving in heat
expenditure is effected, and perpetually clean boilers are provided.
2. The construction of the piston check valves, shown, for the purpose of effecting
high pressure application, with little or no valve leakage.
3. The combination for reversing the engine by the application of one charge of
steam for the purpose, and by the shaft and disc arrangement and connecting gear, as
hereinbefore described and shewn in the drawings.
TA
1. 21
Why 1000
R. MUDGEMARCHANT.
OTHO GILES ABBOTT.