Improvements in Hydraulic Machinery.
Year: 1895

page_text: Date of Application, 23rd July, 18-5-Accepted, 24th Aug.,
1895
COMPLETE SPECIFICATION
Improvements in Hydraulic Machinery.
JOHN SANDERS STEVENS and CHARLES GEORGE MAJOR, Engineers, of
anus Works, Queen's Road, Battersea, in the County of Surrey, do hereby
eclare the nature of this invention and in what manner the same is to be
erformed, to be particularly described and ascertained in and by the following
tatement:-
The objects of our invention are to obtain greater economy in the use of water
power in hydraulic lifts, presses, and similar machinery; and also improved control
of the motions of such machines.
32
In ordinary machines of this class, the consumption of water is invariable,
notwithstanding that the load or other resistance may range through wide limits,
and when dealing with light loads such machines are therefore wasteful of power.
In some machines however, the motive power ram or cylinder, is divided into
two or more of smaller size, and one or more of these rams may be used in combi-
nation according to the load to be dealt with. In this way the water consumption
may be approximately proportioned to the work, and with a group of three or four
rams of varying size, a large number of powers are obtainable by changing the
combinations. The distribution of water to such variable power machines is
sometimes done by hand at the discretion of the attendant, and in other cases, is by
means of more or less complicated devices controlled automatically by the machine
itself. The primary subject of this invention is a simple device for automatic
distribution of the power, and it has no relation to the possible sub-division and
combinations among the rams all of which within useful limits are well known.
ram means either a
For the purposes of description it is herein assumed that "
means either the weight
ram and cylinder or a piston and cylinder; that "load"
raised in a lift or the resistance offered to any press ram; and for illustration a
lift is taken, having three rams (a). (b). (c). Fig. 1, and intended to provide three
different lifting powers.
For the first power the first ram (a) only is employed,
for the second power the first & second rams (a) and (b) are combined, and for the
third power the third ram (c) is added. All the water is passed through a starting
or control valve (d), worked in the usual manner by hand, and which may be of
any of the known forms. We however describe hereinafter a new and improved
form of control valve. The control valve has three positions, the first admitting
water to the machine from supply pipe (e), through pipes (f) and (g); the second
shutting off the machine from both pressure pipe (e), and exhaust pipe (h); and
the third allowing water to flow from the machine by pipes (f) and (y) to the
exhaust pipe (h), and receiving tank (i); from whence pipe (G) leads to drains.
We introduce between the control valve (d), and the machine a small valve
setting cylinder (j), placed preferably in a vertical position and shewn in detail in
Fig. 2. This cylinder or chamber (k) is closed at the top by a cover (1) fitted with
0 a ram (m) working through a suitable stuffing box. The pressure water from the
control valve (d) passes by pipe (f) through the chamber (k) on its way to the
rams (b) and (c), and is also in constant free connection with ram (a) through
pipe (g). This chamber is therefore always subjected to the same pressure as the
lift rams which may at any moment be in action. In the base or floor of the
15 chamber (k) are two openings communicating through pipes (n) and (o) respectively
with the second & third power rams (b) and (c), and closed by pot lid or mushroom
valves (p) and (7), opening upwards and consequently normally held down by the
hydraulic pressure within the chamber (k). These valves are however connected

page_text: to the ram (m) by means of the bridge (r) in such a manner that the upward
movement of the ram (m) will, at certain determinate points, open the valves in
successive order against the pressure within the chamber (k). Communication
will then be established between the control valve (d) and the second and third
rams (b) and (c).
The ram (m) carries at its head a weight (s) constructed in sections that its
amount may be varied. An enlargement (t) is formed upon the ram (m) working
freely in a small cylinder (u) which acts as a dash pot.
The action of the apparatus is as follows:-
Assume that the lift is at the bottom and that the load to be lifted is within the
power of the first ram (a); the control valve (d) is opened by hand, and water
flows directly through pipe (g) to ram (a) which inoves away under pressure in the
usual manner; no movement occurs in the setting cylinder mechanism; the first
ram (a) carries with it the two inoperative rams (b) and (c), which are followed up
by slack water from the tank (1) feeding through non-return valves (v) and (w) in
the usual manner; the three lifting cylinders are thus all filled with water, and
when the control valve (d) is set over to the exhaust position for descending, the
water from the first cylinder (a) flows freely back through pipe () by the way it
came, but the slack water in the other two cylinders will pass by pipes (n) and (0)
to the mushroom valves (p) and (g) which will lift automatically to afford passage,
aud so through chamber (k) and pipe (f) through the control valve, and finally
by pipe () to tauk (i). It should be noted that when the lifting cylinders (a). (b).
and (c) are opened to exhaust, pressure is simultaneously removed from chamber (k).
When the lift ceases to descend the valves (p) and (9) immediately re-scat
themselves.
In a second case suppose a load too heavy for the first power, and within the
capacity of the second power. The first ram (a) could not by itself move when
the control valve admits pressure to it, and to chamber (k), and the pressure in the
latter will almost instantly become equal to that in the pressure main. But the
weights (s) upon the ram (m) are so proportioned that they are insufficient, by
some determinate amount, to hold the ram down against the full pressure, and the
ram will tend to rise; but this tendency is at once resisted by the second power
valve (p) which is coupled to the bridge (r), and has to be lifted against the
hydraulic pressure. The conditions now are that the weight (s) acting together
with the hydraulic pressure on valve (p) tend to hold the ram (m) down against
the pressure beneath it. The latter is designed to have the preponderance and the
valve (p) is lifted. The conditions are then however immediately aud substantially
changed, for pressure is now admitted beneath the mushroom valve (p), which is
at once put into approximate equilibrium, the weights (s) are robbed of the
assistance of the pressure upon valve (p), and the ram (m) which at first had
only a small preponderance of power, now has a very considerable preponderance,
and moves upward till it reaches the point where it would lift the third power
valve (g), which being still closed and under pressure resists any farther motion
of the ram (m), and forms an effective and definite stop.
100
The opening of the second power valve (p) has in effect increased the acting
area of the ram (m), and the valve is given an otherwise unnecessary amount of
area to make the difference substantial, a point of importance for the following
reason. The load which was too great for the first lifting ram (a), may have been
only slightly, say ten per centum, in excess of the first power; but the second
ram (b) is, say, equal in area to the first, and the lifting power is increased by it
per centum, and there is now;200 of power area to deal with 110 of load; but
the pressure cannot exceed the resistance, and in the chamber (k) it therefore falls
in the proportion of 200 to 110, and if the effective area of ram (m) were not at
the same time increased, the weights (s) would overpower the ram (m) and drive
it down till by reclosing the valve (p) and throttling the flow of water, equilibrium
was restored. This would be. at the expense of speed in the machine, which with
our device is maintained by means of a fully opened valve.

page_text: An alternative defect avoided, by the variable power given to
ssible indefinite dancing movement of the valve (p) about the nearly closed
sition, when the load is only just outside the power of ram (a).
Another object attained by this arrangement, is the definite stop of the ram (m),
en the required valve is fully opened, and the non-opening of additional
required powers. If, for instance the resistances of the mushroom valves (p)
d (g) were absent, and say slide valves were substituted, there would be no reason
hy the ram (m) once started into 'motion, should not continue, & open more
wers than required, before the pressure in chamber (k) could readjust itself by..
e machine getting to work; for it is well known that the friction of motion is.
ss than that of repose. The effect would be first an impulsive start of the
achine under an excess of power, and then à slowing down as the ram (m) returned
its proper position.
In the third case of a load requiring all three rams (a). (b) and (c), the second:
ower valve (p) would be opened as described, but as the power of two rams (a)
nd (), would be insufficient, the pressure in chamber (k) remaining unimpaired
would cause the ram (m) to continue moving till the third power valve (g) were
pened, with results as described in the case of the second power.
The exhaust for lowering is effected in all three cases in the same manner as
lescribed for the first.
It will be understood that the valves (p) and (g) are so mounted in the bridge (1)
that they are free to rise for passage of exhaust water without requiring any
movement of the ram (m); and also that the latter lifts the second power
valve (p) with its first motion, for the moment leaving all other valves seated;
that it next picks up the third power valve (g), and successively any number which
may be required.
For the purpose of preventing the motion of the ram (m) becoming too rapid
we form it with an enlarged collar (t) working in a chamber (u) placed imme-
chamber being that of a
diately beneath the cover (1), the action of collar
piston and dash pot or cataract, and so serves to retard the motion of rain (m) and
valves (p) and (q).
When the controlling valve (d) places the chamber (k) in communication with
the exhaust, the ram (m) drops to the bottom of its travel, and is ready to re-set
the valves on the next journey.
If the load is varied during the ascent of the lift, it will be seen that the setting
ram (m) will at once accommodate itself to the variation. This is important in
that class of lifts known as "hydraulic balance" in which long vertical rams are
often left uncompensated for protrusion. Such lifts will start from the bottom
with a much lighter pressure than they require at the top, but the maximum
Our invention will enable
power is at present provided throughout the travel.
such lifts to start with a small power, and give the additional only when required
by growing protrusion.
.
In the arrangement described we make the weights (s) adjustable either in
amount by loose sections, or in position along a lever (v) Fig. 3, and it thereby
becomes possible to vary at will the pressure in chamber (k) at which the successive
admission valves shall be opened; the effect being that the machine may be made
to take more power while still possessing a good margin of lifting capacity, or on
the other band the addition of power may be delayed till the load nearly equils
In the former case water is used to maintain
the power of the acting ram or rams.
speed; in the latter, nearly the whole of the lifting effect of the water may be
utilised at the expense of speed.
'
In some cases the weights (s) would be inconveniently large and we then adopt
the alternative arrangement shewn in Fig. 4 wherein the chamber (k) and all its
fittings remain the same as described herein before but the ram (m) is continue.
55 into a second inverted hydraulic cylinder (w), which at its upper end is fitted
·with a second ram (a) of much smaller diameter; and carrying on its hea
weights (s). When ram (m) is intruded into cylinder (w) any given distance th

page_text: smaller ram (a) must be extruded a greater distance in inverse proportion to their
respective areas, and as the weight (s) partakes of this increased movement it
may be reduced in amount in the same ratio as the ram areas. Leakage from (w)
may be replenished either from the pressure main or from the tank (i.)
Any other of the known devices for increasing the movement of (s) relatively to
that of (m) and so reducing the mass of (s), may be employed without departing
from the substance of our invention.
In another alternative arrangement the ram (a) and weight (s) of Fig. 4 may be
suppressed and pressure water brought to cylinder (w) direct from the pressure
main. In this case the end of ram (m) entering cylinder (w) must be of smaller
. diameter than that working in chamber (k), that the latter may have the described
requisite preponderance of power. Direct hydraulic pressure would thus take the
place of the weight (s), but in all other respects the action would be as described
for Figs. 1 and 2.
In this arrangement we sometimes provide adjustable weights upon ram (m)
between the glands of cylinders (k) and (w) for the purpose of varying the
promptitude of action as described for Fig. 3.
In another arrangement we bore the cylinder (k) as in Fig. 5, and fit it with a
piston (m) carrying a spindle (y) projecting through the cover and thus forming an
annular space (s) on the upper side of piston (m). Pressure water is admitted to
this annulus by pipe (2) direct from the main, and its pressure upon the annulus
takes the place of the weights (s) acting in opposition to the upward hydraulic
pressure beneath piston (m) which replaces ram (m); and the motions and action
are all as already described. A small amount of weight is carried on spindle (y)
for adjusting purposes. Control of speed is given by making the orifice from
pipe (2) to annulus (s) very small.
We apply our invention to packing & baling presses by two separate methods.
In the first a press is made with a number of rams supplied with pressure water
according to the needs of the increasing squeeze given to the bale, automatically
by means of a valve setting apparatus as described in Figs. 1, 2, 3, 4, and 5 :—and
in the second method simple presses of the ordinary construction with one ram may
be used, and the pressure applied through an intermediate group of regulating
rams, controlled by a valve setting apparatus as described and shown in
Figures 1 to 5. The group of regulating rams might for instance receive water
from a pressure service at 1000 lbs. per square inch, and might commence the
movement of the press ram with a pressure upon it of only 100 lbs. per square
inch, gradually bringing more rams into action till a final pressure of say 7000 lbs.
were attained. A large number of press rams could be served by one group of
regulating rams, as the time occupied in actual pressing is small as compared with
the time required for preparing the bale, bonding, covering, etc.
Fig. 6 illustrates such a group of regulating rams.
water direct from the controlling valve (d) Fig. 1; and gives the first power.
The centre one (a) receives
Rams (bb), receive either slack water through non-return valve (v), or pressure
water through the valve setting apparatus (j) and together with (a) give the
second power; and so on, rams (c c) being added for third power, and rams (AA)
for fourth power. Other powers may be added as required. The cylinder (B) for
ram (a) acts also as a ram in cylinder (C) from which the water at varying pressure
flows through pipe (D) to the presses. All the smaller cylinders of the rams (bb),
(cc), and (A A) are secured to ram (B) by means of the crosshead (E) and when
the group of driving rams are connected with the exhaust their cylinders together
with cross head (E) return by their own weight. A portion of the exhaust water
'flows through non-return valve (F) and refills cylinder (C) ready for the next press,
while the surplus goes to tank (i). Each press is fitted with a non-return valve
and a screw stop to retain the intensified pressure when supplied. Fig. 7 is a play
of the group of regulating rams.
The second part of our invention relates to the controlling valve (d) of such
machines, and is also applicable to controlling valves of all hydraulic machines.

page_text: "
"
he valves generally in use give rise to much noise & difficulty-m
articularly those used with pressures ranging from 400 lbs. per square inch
pwards. For the purpose of avoiding such defects, we use a valve consisting
These
fa case (A) Fig. 8 containing three chambers, that is (B) in connection with
he pressure, (C) with the lift cylinders, and (D) with the exhaust.
hambers are arranged in the above order along a common centre line, and are
eparated by walls bored to a uniform size and fitted with hydraulic leathers as
acking. A valve spindle (E) of solid metal passes through the chambers
rom end to end along the centre line and through the packing collars. The spindle
s generally parallel, but is formed with a long depression (F) or reduced diameter
When the large or parallel portions of the spindle
or a part of its length.
coincide with the leather collars, which they fit, the various chambers are completely,
separated and the lift stands still. If the spindle (E) is moved end wise so that the
reduced diameter (F) comes opposite the leather dividing the pressure chamber (B)
from the lift chamber (C), it allows water to pass this leather and the lift ascends..
Conversely if the spindle (E) is moved the opposite way, so that the end is drawn
out of the last leather, water passes from the lift chamber (C) to the exhaust.
chamber (D) and the lift descends. The exhaust end (G) of the spindle (E) and
the junction (H) between the reduced portion (F) and the parallel portion of the
spindle (E), that is to say the two points which pass in and out of the leathers, are
curved in a peculiar way shewn enlarged in Fig. 9, and this form of curve conduces
to both silence and the preservation of the form of the leather cups, with ready
In case the curved form referred to might allow the lip of
passage through same.
the leather to fall in upon the spindle, and prematurely cut off the flow of water,
we drill the spindle at each of the two required points (II) with one small hole
transversely and connected therewith another longitudinally in such a manner that
a small quantity of water may still pass through the body of the spindle after the
fall of the leather lip, and continue to do so till the transverse hole has also passed
the lip, thus causing a definite cut off at the desired point. A valve such as this
will require no lubrication; and cannot fall away from its seat should the pressure
be withdrawn.
A modification of this valve is shewn in Fig. 10 in which the spindle (E) is cut
in two and worked by a double ended lever in two separate chambers (B) and (D)
The lever (J) may be replaced with a
both connected with the lift chamber (C).
toothed wheel engaging with two racks attached to (E E).
shewn in Fig. 11 in which also the
Another modification we sometimes use
spindle is divided into two sections connected by means of crossheads (K K), a
tie (L) and a toothed rack (M), through which the valve receives motion from
the pinion (N).
The same letters of reference are used throughout the figures to indicate the
same or equivalent parts.
Although we have described several methods of applying our invention, we wish
it to be understood that we do not confine ourselves to those particular methods, as
many other mechanical equivalents are possible without departing from the
5 substance and nature of the invention.
Having now particularly described and ascertained the nature of our said inven
tion and in what manner the same is to be performed, we wish it to be understood
that we do not bind ourselves to the exact details of the different forms o
apparatus herein set forth, but do declare that what we claim is
50 (1.) In a hydraulic machine with variable powers, the combination of a valve
setting cylinder with one chamber only; a ram loaded with weights placed directly
upon it, or by means of a lever; one or more distributing valves varying th
effective area of the setting ram; and the bridge for lifting the distributing valve
in the required order as shewn in Figs. 1. 2. & 3 substantially as and for th
55 purposes described.
(2.) In a variable power valve setting cylinder as shewn in Figs. 3. 4. & 5 th

page_text: combination of setting ram with collar and dash pot as in Fig. 2 substantially as
and for the purpose described.
(3.) In a hydraulic machine with variable powers the combination of a valve
setting ram or piston in any of the forms described and shewn in Figs. 2, 3, 4,
and 5 with weights adjustable as to quantity, or as to position along a lever,
substantially as and for the purpose described.
(4.) In a hydraulic machine with variable powers, the combination of a valve
setting cylinder of two chambers, having therein two opposing rams of differential
area united each to the other, with a third ram working separately with a relatively
long stroke carrying a proportionately small weight and a fluid piston between the
second and third rains, as shewn in Fig. 4, substantially as and for the purpose
described.
(5.) In a hydraulic machine with variable powers, the combination of a valve
setting cylinder of two chambers having therein two opposing rams of differential
area united each to the other and having constant hydraulic pressure in the upper
chamber, with one or more distributing valves varying the effective area of the
lower ram, and the bridge for lifting the distributing valves in the required order,
substantially as and for the purposes described.
(6.) In a hydraulic machine with variable powers, the combination of a valve
setting cylinder of two chambers separated by a piston, with one or more
distributing valves varying the effective area of the piston, and the bridge for
lifting the distributing valves in the required order, as shewn in Fig. 5, substantially
as and for the purposes described.
(7.) In a hydraulic press with multiple rams and variable powers, the combination
with an automatic valve setting device as shewn in Figs. 2. 3. 4. and 5, substantially
as and for the purpose described.
(8.) For use with hydraulic presses, a group of regulating rams and cylinders of
any desired number as shewn in Figs. 6 and 7 in combination with an automatic
valve setting device as shewn in Figs. 2. 3. 4 and 5, substantially as and for the
purposes described.
(9.) In a hydraulic machine the improved form of controlling valve as shewn in
Figs. 8. 9. 10. and 11, substantially as and for the purposes described.
1 :
Dated this 23rd day of July 1895.
JOHN SANDERS STEVENS.
CHARLES GEORGE MAJOR.