IMPROVEMENTS IN HYDRAULIC ENGINES
Year: 1884

page_text: I, DAVID JOHNSTON, of 96 Buchanan Street, Glasgow, Lanarkshire, Consulting
Engineer, do hereby declare the nature of my said Invention for "IMPROVEMENTS
IN HYDRAULIC ENGINES," to be as follows:-
My Invention consists of improvements in the construction and arrangement of
the valves and valve actuating details and of other parts of hydraulic engines
intended mainly for use as pumping engines, for winding and for other purposes in.
connection with mining operations.
According to my invention I employ two reciprocating piston valves of a peculiar
form to control the admission and discharge of the water to the cylinder of the
hydraulic engine, and these valves I fit within a long cylindrical casing or series of
casings arranged in line.
The piston valves are fitted on a long rod or spindle of nearly the full length of
the valve casing, and at some distanco apart on the spindle, each end of which is
fitted with a suitably packed plunger by which the valves are actuated as herein-
after described.
Between the piston valves, an inlet orifice is formed in the valve casing or
chamber through which the water employed to operate the engine enters, and in
the portion of the length of the valve casing in which the valves reciprocate on
each side is formed a port or passage communicating with the corresponding end of
the engine cylinder. The valves being on a single spindle are operated in unison
and they are so placed that when one passes over and uncovers the port on one side
to open the communication from the inlet opening to the corresponding end of the
cylinder, the other valve uncovers the other port and places it in communication
with a discharge orifice in the valve casing beyond the valve; or vice versa.
valve consists of a piston fitting a liner in the valve casing of greater diameter in
its mid length than at the ends, and on each side of the piston a series of rings are
built of smaller diameter to fit the ends of the liner an annular face being left on
each side of the piston, and being covered with leather or other material.
Each
When the valve on one side of the central inlet is at its outstroke, the other
valve is at the instroke and both fit tightly against faces formed in the liners, and
prevent the flow of water direct from the inlet to the discharge orifices, which are
on the other side of each valve. In this way the valves seal the orifices and
combine the advantages of clack valves with those of piston valves, and they are
perfectly tight under any pressure of water. The water from the inlet then freely

page_text: passes by the port uncovered by the valve which is at its outstroke, to the end of
the cylinder, and the water from the other end of the cylinder escapes through the
port uncovered by the opposite valve which is at its instroke.
While the valves are traversed to the opposite end of the stroke the communi-
cation between the cylinder ports and the inlet and outlet orifices is momentarily
cut off by the rings or bosses on the ends of the pistons fitting the ends of the
liners, but as the valves complete their stroke the opposite cylinder ports are put
in communication with the inlet and outlet orifices respectively, and the direction
of the flow is reversed. The actuation of the valves at the proper time may be
effected by rods, levers and tappets or equivalent mechanical devices from the
piston rod of the engine, but I employ by preference the following arrangement.
Each end of the valve spindle is fitted as before mentioned with a plunger, said
plunger working in a cylindrical chamber. The outer end of each chamber com-
municates by a port or passage with a valve chest in which is fitted an ordinary
D slide, or similar distributing valve, the valve and ports being arranged as in a
steam engine, and an exhaust port being provided. The water operating the engine
is admitted to the slide valve chest, and it is admitted by that valve to the port
communicating with the chamber at one end of the piston valve chest or to that
communicating with the other chamber, and it acts on the corresponding plunger
and traverses the piston valves in one direction or the other, and holds the clack
rings tight against the valve faces during the entire stroke of the engine. This
slide valve might be actuated from the engine by mechanical devices but I prefer
to operate it also by water pressure, and with this object I fit it in a casing the
ends of which form barrels for small plungers. On the ends of each of these
plungers alternately water pressure is applied by means of minute pumps which
consist simply of small barrels fitted with plunger rods which are struck at the
termination of each stroke of the piston of the engine.
These pumps are in communication with opposite ends of the slide valve casing,
and when acted on they transmit through pipes connected to the plunger barrels,
the pressure imparted to the water on them whereby the plungers and with them
the slide valve are traversed to the requisite extent.
The main object of employing water pressure to communicate the motions to the
valves in the manner described, is to avoid the risk of derangement and difficulty
of replacing parts which become disconnected in engines employed under ground."
Where ordinary facilities for repairing are not available. To facilitate renowal
of the barrels or cylinders of such engines or of the pumps to which they are
connected I form the cylindrical barrel of the engine or pump in a separate casting
from the ends or end casings, and I cast a flange near each end of the barrel, so
that the barrel may be tightly jointed to the casing at each end, and when one
barrel becomes worn out it may be taken out and easily replaced by a similar
barrel or if desired by another of different size. The end casings are cast with
flanges and are drawn tightly together on the barrel to tighten up the joints by
strong stay bolts extending from end to end of the barrel. In engines of the kind
described it is not necessary that the valve casing should be fitted directly to the
cylinder or engine body, but they may be connected thereon by long tubes serving
as the ports from the cylinder to the valve casing.
Dated this Third day of September 1884

page_text: COMPLETE SPECIFICATION.
I DAVID JOHNSTON of 96 Buchanan Street Glasgow Lanarkshire Consulting
Engineer do hereby declare the nature of my invention for "IMPROVEMENTS IN
HYDRAULIC ENGINES and in what manner the same is to be performed to bo
particularly described and ascertained in and by the following statement :-
"
My invention consists of improvements in the construction and arrangement of
the valves and valve actuating details and of other parts of hydraulic engines
intended mainly for use as pumping engines, for winding and for other purposes in
connection with mining operations.
A modification of my improved hydraulic pumping engine is illustrated in longi-
tudinal section and sectional end elevation in figures 1 and 2 of the accompanying
drawings.
The pumping engine illustrated is intended particularly for mining purposes in
which case it is usually operated by the pressure due to the head of water in the
ising main in the mine shaft, a water supply pipe being connected from the main
pipe to the valve casing of the hydraulic engine to operate the engine cylinder A
while the water pumped through the pump barrel B is discharged through pipes
led up to the required level.
I employ two reciprocating piston valves C. D of a peculiar form to control the
admission and discharge of the water to the cylinder A of the hydraulic engine,
and these valves I fit within a long cylindrical casing or series of casings E
arranged in line. The piston valves C. D are fitted on a long rod or spindle c of
nearly the full length of the valve casing, and at some distance apart on the spindle,
each end of which is fitted with a suitably packed plunger F by which the valves
are actuated as hereinafter described. Between the piston valves an inlet orifice G
is formed in the valve casing or chamber E through which the water employed to
operate the engine enters and in the portions of the length of the valve casing in
which the valves C. D reciprocate on each side is formed a port or passage H H¹
communicating with the corresponding end of the engine cylinder. The valves
C. D being on a single spindle are operated in unison and they are so placed that
when one C passes over and uncovers the port on one side to open the communi-
cation from the inlet opening G. H to the corresponding end of the cylinder A the
other valve D uncovers the other port and places it in communication with a dis-
charge orifice I in the valve casing beyond the valve or vice versa. Each valve
consists of a piston fitting a liner e the valve casing E of greater diameter in its
midlength than at the ends and on each side of the piston a series of rings are
built or a soft metallic boss is formed of smaller diameter to fit the ends of the
liner an annular face being left on each side of the piston and being covered with
leather soft metal or other material. When the valve C on one side of the central,
inlet is at its outstroke the other valve D is at the instroke and both fit tightly
against faces formed in the liners e and prevent the flow of water direct from the
inlet G. to the discharge orifices.I which are on the other side of each valve-In
this way the valves seal the orifices and combine the advantages of clack valves
with those of piston valves and they are perfectly tight under pressure of water.
The water from the inlet G then freely passes by the port H uncovered by the

page_text: valve C which is at its outstroke to the end of the cylinder A and the water from
the other end of the cylinder escapes through the port H¹ uncovered by the
opposite valve which is at its instroke. While the valves are traversed to the
opposite end of the stroke the communication between the cylinder ports HH'
and the inlet G and outlet orifices I is momentarily cut off by the rings or bosses
on the ends of the pistons C D fitting the ends of the liners e but as the valves
complete their stroke the opposite cylinder ports are put in communication with
the inlet and outlet orifices respectively and the direction of the flow is reversed.
The actuation of the valves at the proper time may be effected by rods levers and
tappets or equivalent mechanical devices from the piston rod of the engine but
I employ by preference the following arrangement. Each end of the valve spindle
is fitted as before mentioned with a plunger F said plunger working in a cylindrical
chamber E. The outer end of each chamber E communicates by a port or passage k
with a valve chest K in which is fitted an ordinary piston valve D slide or similar
distributing valve L, the valve and ports being arranged as in a steam engine and
an exhaust port being provided. The water operating the engine is admitted to
the slide valve chest K by a port and it is admitted by that valve L to the
port communicating with the chamber E at one end of the piston valve chest or
to that communicating with the other chamber and it acts on the corresponding
plunger F and traverses the piston valves in one direction or the other and holds
the clack of the valve rings C D tight against the valve faces, during the entire
stroke of the engine. This slide valve L may be actuated from the engine by
mechanical devices such as the levers O and tappets P or by water pressure. I fit
the valve L in a casing K through the ends of which pass small plungers m
connected to the levers O and which act on the valve L. The ends of each of
these plungers are acted on alternately by the levers O operated by the tappets P
or water pressure may be applied by means of minute pumps which consist simply
of small barrels fitted with plunger rods which are connected by the levers O and
tappets P struck at the termination of each stroke of the piston of the engine.
These pumps are in such case in communication with opposite ends of the slide
valve casing and when acted on they transmit through pipes connected to the
plunger barrels the pressure imparted to the water on then whereby the plungers
and with them the slide valve are traversed to the requisite extent. The main
object of employing water pressure to communicate the motions to the valves in
the manner described is to avoid the risk of derangement and difficulty of
replacing parts which become disconnected in engines employed underground where
ordinary facilities for repairing are not available.
To facilitate removal of the barrels or cylinders of such engines or of the pumps
to which they are connected I form the cylindrical barrel A or B of the engine or
pump in a separate casting from the ends or end casings A' or B' and I cast a
flange a or b near each end of the barrel so that the barrel may be tightly jointed
to the casing at each end and when one barrel becomes worn out it may be taken
out and easily replaced by a similar barrel or if desired by another of different
size. The end casings A-B' are cast with flanges and are drawn tightly together
on the barrel to tighten up the joints by strong stay bolts S extending from end to
end of the barrel. The arrangement of removable barrel described may be applied
to hydraulic engines and pumps generally.
In engines of the kind described it is not necessary thet the valve casings
should be fitted directly to the cylinder or engine body but they may be con-
nected thereto by long tubes serving as the ports from the cylinder to the valve
casing.
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

page_text: 2 The arrangement in a hydraulic engine or pump of the valve chamber and
valves C. D actuated automatically by water pressure or by mechanical devices
substantially as set forth.
3 The arrangement in a hydraulic engine or pump of a movable and inter-
changeable cylinder or barrel formed with flanges adapted to fit suitably formed
end casings substantially as set forth.
4 The arrangement in a hydraulic engine or pump of the valves C. D serving
both as piston valves and clack valves substantially as herein described.
0012
1007