Improvements in Liquid Pressure Engines.
Year: 1897

page_text: Date of Application, 23rd Mar., 1897-Accepted, 15th May, 1897
COMPLETE SPECIFICATION.
Improvements in Liquid Pressure Engines.
I, JOHANN STUMPF, of 19 Lessing Street, of Berlin, in the Kingdom of
Prussia, German Empire, Professor 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 refers in general to bydraulic motors of the class in which the
motive power is applied to reciprocate a piston, and in particular to the valves of
such motors and to the means for actuating said valves. The characteristic
feature of my invention resides in a particular reciprocal action of the valves, in
that (some of) these latter after having been compulsorily closed by a suitable
mechanism, shortly before the piston has finished its stroke, cause the opening of
the other valves by aid of a relative vacuum and a relatively excessive pressure
resulting from the continued movement of the piston. The induction valves as
well as the eduction valves are so arranged as to open in a direction contrary to
the direction of the water streaming into, and issuing from, the motor.
The
mechanical valve-gear (which, if desired, may well be operated by the piston of
the motor) closes said valves compulsorily shortly before the piston has reached
the end of its path; that is to say, in a single-acting motor there is, of course,
actuated either the induction-valve or the eduction valve, whereas in a double-
acting motor the induction-valve at one end of the cylinder and the eduction-valve
at the other end of the cylinder are simultaneously operated. There results in
this case a relative vacuum at one side of the piston, and a relatively excessive
pressure on the other side of the piston, in consequence of which vacuum and
pressure the other eduction valve and the other induction-valve are opened. The
valves are made so weighty, or are so acted on by springs, that they remain open
during the time the water passes through between the valves proper and their.
seats, and are closed only when the mechanical means above referred to come into
effect.
Hydraulic motors having their valves operated in the manner afore described
do not require fly-wheels or the like; they may be directly coupled to the machines.
they are intended to drive, and are especially suited for working pumps; they may
well be used for exhausting the energy of falls of water having a high head and
a small flow.
The valve-gear may be employed with single-acting motors, as well as with
double-acting ones, and also with such in which a differential-piston is made
use of. To attain an especially secure working two motors of the kind in question
may be combined with each other, the valve-gear of one motor being then
preferably operated by the piston or piston-rod of the other motor, and reversely.
In the accompanying drawing Figure 1 represents a side-view of a double-acting
motor constructed according to my invention, and Figure 2 is a vertical section
through that motor.
The latter is constructed as follows:
The piston a moves within the cylinder e that terminates at one end into the
valve-chamber i and at the other end into the valve-chamber . The water which
is to drive the motor passes through the port o' into the chamber o and flows then
upwards around and over one of the induction-valves u. The water then enters'
the respective valve-chamber and acts in known manner upon one side or end of

page_text: the piston.
The water supplanted out of the other valve-chamber by the other
side or end of the piston flows over and around the respective. eduction-valve r and
leaves the motor through the piece of tube s. As already mentioned the valves
are so arranged as to open in a direction opposite to the direction of the water, and
they are kept open by their own weight or by springs, or by both these means
combined. After the valves have been compulsorily closed the closure is securely
maintained by the pressure of the water also after the means that effected the
closing of the valves have ceased to act.
Each of the induction-valves u has a hollow outwardly or downwardly-projecting
stem or sleeve which consists of two parts of different diameter, and slides upon a
vertical guide-rod & fastened at its upper end in a spider in the inlet port, and at
its lower end in a socket at the base of the chamber o. On the sleeve of the
valve u, between the two parts of different diameter, is a flange u', and loose upon
the lower part of said sleeve is an outer sleeve having a flange z. Surrounding
this outer sleeve and confined between the flanges u¹ and is a spiral spring m
which tends to press the said outer sleeve downwards against a stop-nut w on the
lower portion of the sleeve of the valve u.
The eduction-valve has an upwardly or outwardly projecting stem ¹ which
slides through the adjacent stationary guide-sleeve, and has a reduced and
threaded upper end portion x 2. The neighbouring ends of the parts a¹ a 2 form a
shoulder, as shown. Loosely surrounding the lower part of the screwed stem x 2
is a flanged sleeve or bearing piece b, and screwed upon the upper end of the stem
is a flanged sleeve bl which moves through a guide-opening in a spider at the top of
the casing. Confined between the flanged sleeves b is a spiral spring m' which
tends to press the sleeve or bearing-piece down against the shoulder between the
parts 2 of the stem.
Extending through the shell of the chamber a below each of the induction-
valves is a rock-shaft journalled in a suitable stuffing-box and extending past the
adjacent part of the sleeve of the valve u. Firmly secured to each rock-shaft / is
a bifurcated lever or finger ', which straddles the adjacent nut w, and bears against
the under surface of the flange . Extending through the shell of the motor above
each eduction-valve r is a rock-shaft h 2 suitably journalled in a stuffing-box in the
shell, and carrying a bifurcated lever or finger 13 to engage the under surface of
the bearing-piece b.
The shafts h 2 at one end of the motor are provided beyond the shell with.
bell-crank levers tt, Figure 1, and the other shafts are provided with crank-
arms t2 13. The two bell-crank levers t t are connected with each other by a
rod t 4, and with the crank-arms t 2 t 3 by rods t5 t 6. Motion is applied to this
system of levers or cranks and rods by the rod t 7.
Owing to the different configuration and position of the bell-crank levers t t', as
shown; the levers t t 2 are moved to the left when the levers t¹ t 3 are moved to the
right, and reversely, and owing to the levers of the shafts h, as well as the
levers 3 of the shafts 2 extending one in the direction to the other, the induction
valves, are operated alternately, as are also the eduction valves in such a manner,
that the left-band induction valve and the right-hand eduction valve are opened
and the right-hand induction-valve and the left band eduction-valve are closed all
at a time, and reversely.
Supposed, the piston a move in the direction indicated by the arrow in Figure 2,
the water will pass from the chamber o into the chamber i around and over the
left-hand induction-valve u, whereas the water expelled out of the chamber
passes over and around the righthand eduction-valve r. Shortly before the piston
arrives at the end of its path said two valves are compulsorily closed by the
mechanism just described, and there will thus arise a relative vacuum within the
chamber i, and a relatively excessive pressure within the chamber 1. Owing to
these actions the righthand induction valve as well as the left-hand eduction-valve
will be opened, which occurs either very shortly before the end of stroke of the
piston, or just within the moment in which the direction of motion of the piston

page_text: changes. To effect within the valve-chambers
the piston need make but a very short way.
the two actions just mentioned
After the respective two valves have been freed from the action of the
levers h 3, and after their opening has been initiated by the relative vacuum
on one side and the relatively excessive pressure on the other side or end of the
piston, they are kept open either by their own weight, or by springs or by both
these means combined, as has already been mentioned in the preamble, and they
remain open until the levers 1 h 3 come again into play.
The mechanisms for operating these levers need not indispensably be arranged
outside the pump (as shown in Figure 1) but may be arranged, if desired, inside
the same; and instead of letting the mechanisms in question, or equivalent ones,
be operated from the machine or pump driven by the motor I may provide.
the piston-rod with (adjustable) collars for actuating the respective mechanical
system at proper times, or I may cause the piston to push on displaceable parts
which in their turn move the levers 3 in the requisite way. These are mere-
constructive changes which will be clear without any description to every expert.
in the art in question.
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 hydraulic motor having its valves opening in the direction opposite to
that of the water, the combination with said valves, of means for closing the open
valves compulsorily shortly before the end of stroke of the working piston of the
motor; the other valves being opened in consequence of the relative vacuum and
the alternatively excessive pressure resulting from the continued movement of said.
piston, as set forth.
2. In a hydraulic motor having its valves opening in the direction opposite
to that of the water, the combination with said valves, of means for closing
the open valves compulsorily shortly before the end of stroke of the working
piston of the motor, the valves having such a weight or being acted on by
springs of such a tension that the water cannot move them against their seats, as
set forth.
3. In a hydraulic motor having its valves opening in the direction opposite to.
that of the water, the combination with said valves, of levers arranged to move the
open valves against their seats, and mechanical means for compulsorily operating
said levers in this way shortly before the end of stroke of the working piston of
the motor, as set forth.
Dated this 22nd day of March 1897.
JOHANN STUMPF,
By Geo. H. Rayner,
Agent for the Applicant.