Improvements in Valves and Piston Rods for Compound Engines.
Year: 1893

page_text: Date of Application, 23rd Feb., 1893-Accepted, 13th May, 1893.
COMPLETE SPECIFICATION.
Improvements in Valves and Piston Rods for Compound Engines.
We, FRANCIS CHARLES SIMPSON, FREDERIC STRICKLAND, PHILIP PEM-
BROKE ALEXANDER, and GEORGE KINGDON, Engineers, Dartmouth, South
Devon, 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 valves and piston rods for compound
engines, the object being arranging one slide valve in one steam chest, that the.
steam from the high pressure cylinder may pass through said valve to the low
pressure cylinder at each travel, to be there re-used before escaping to the condenser,
or to the atmosphere.
The second object is to dispense with stuffing box, or gland in the partition plate
which divides the two cylinders.
Our valve is formed with a wider, or more open port at one end than at the
other, that it makes a connection with each exhaust port of the high pressure
cylinder at the termination of each stroke of the pistons for the passage of the
used steam through the valve to the entry port of the larger or low pressure
cylinder, the cylinders being attached or formed in one casting, or otherwise.
The rod of the high pressure piston is formed with annular grooves and pro-
jecting rings, which rings fit the wall of the aperture in the partition plate between
the two cylinders, and form a steam tight joint at that part, whereby the usual
stuffing box at that part is dispensed with.
The invention is applicable to all compound engines, marine, land, and
locomotive.
Our invention is shown in the annexed drawings in which
Figure 1 is a sectional view of a compound engine of combined high and low
pressure cylinders as one structure, suitable for driving a screw propeller, or any
kind of machinery.
A is the improved valve formed with a large port or aperture B of sufficient
width to serve for both the ports H, D, in the high pressure cylinder, and com-
municates with a passage C and ports B1, B2, which correspond during the move-
ments of the valve with the low pressure cylinder ports F, F¹.
Steam from the boiler enters the steam chest at R, or other convenient part, and
is distributed in the following manner, that is to say, with the pistons at the extreme
top ends of their stroke, the valve A is just moving down to uncover the port H
to the steam chest and admits live steam to the top side of the high pressure
piston I, and opens communication between the under side of said piston and the
top of the low pressure piston J by means of the wide port B, passage C ports B¹
and F respectively to exhaust the steam from the cylinder E for further work upon
The valve A
the piston J, the port B2 being closed upon the face of the cylinder.
is at the same time commencing to uncover the exhaust port S for exhausting the
steam from the under side of low pressure cylinder to the condenser, or atmosphere,
as the case may be, through the cylinder port F and valve port U. When the
pistons I, J, have arrived at their extreme lower position, the valve A will begin
to uncover the port D to the steam chest for admission of live steam, the recess T
being formed for this purpose, and the port B will open communication between
the top side of the high pressure cylinder E, and underside of the low pressure
cylinder G through the ports H, B, C, B2, and F¹ respectively, B₁ being closed
upon the cylinder face. The top side of the cylinder G will also communicate with
the condenser or atmosphere through the cylinder port F, valve port U, and
exhaust S, and so on consecutively. Both pistons are connected to the same rod K

page_text: to actuate the crank shaft L through the connecting rod M in the well known
manner.
Figure 2 is a plan view of the seating, or face on which the valve slides to and
fro, the ports being shown.
Figure 3 is a sectional elevation of an equilibrium tubular valve arranged as
described for the friction valve shown in Figure 1, the ports H, D, F, F', of the
cylinders E, G, being also arranged in a similar manner.
The second part of our invention is shown in Figure 1, where N is the ringed
and grooved portion of the piston rod K, which passes through the internal cover P
of the cylinder-G, whereby the usual glands and packing are dispensed with, the
central portion Q having a raised shoulder that never less than three of the rings
bear against the inner wall in the to and fro movement of the rod K.
We have shown the internal cover as part of the casting of the two cylinders E
and G, it may however be a separate cover bolted in place between the two
cylinders.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. Providing the valves of compound engines with an end port of greater width,
or more open than the other ports of said valve, that the exhaust steam from the
high pressure cylinder may pass to exert its remaining force upon the piston of the
low pressure cylinder, as set forth, said valve being like that shown in Figure 1; or
an equilibrium, as in Figure 3 of the annexed drawings.
2. Forming that part of a piston rod, which works through the internal cover of
a compound engine, with grooves and rings, as set forth and shown in Figure 1 of
the annexed drawings, whereby the usual stuffing or packing box in said cover is
dispensed with, as described.
3. The compound engine shown in Figure 1 of the annexed drawings, especially
the valve with a wide port, and the ringed and grooved piston rod as part thereof,
the whole acting, as and for, the purposes set forth.
Dated this 23rd day of February 1802
H. GARDNER,
Patent Agent, 166, Fleet Street, London,
Agent for the said Francis Charles Simpson, Frederic Strickland,
Philip Pembroke Alexander, and George Kingdon.