Improvements in or connected with Valves for Hydraulic Machines.
Year: 1897

page_text: Date of Application, 17th June, 1897
Complete Specification Left, 15th Mar., 1898-Accepted, 23rd Apr., 1898
PROVISIONAL SPECIFICATION.
Improvements in or connected with Valves for Hydraulic Machines.
I, REGINALD EMPSON MIDDLETON, of 17, Victoria Street, Westminster, in the
County of Middlesex, Civil Engineer, do hereby declare the nature of this invention
to be as follows:-
The said invention relates to the construction of the valves employed for starting,
stopping, or otherwise regulating the working of hydraulic machines.
It applies
more particularly to valves of the "slide valve" class, but may also be used in con-
nection with other kinds.
The ordinary forms of slide valve used for the above described purposes, are
unbalanced, and the heavy pressures under which they sometimes work, soon cause
deterioration of the faces and consequent leakage, while in the event of the sudden
cessation of the water supply from the bursting of the main, or other cause, such
valves are liable to leave their faces, and the machine to which they are connected
cannot then be controlled.
In the case of a lift, or crane such failure of the valve may cause serious damage,
as the lift-cage, or load will descend without the possibility of any check being
applied.
The main objects of the present invention are to remedy these defects by provid-
ing efficient means for balancing the valve and for automatically holding it to its
face, not only in the event of sudden failure of the water supply, but under all other
conditions of working.
The following description of the application of the invention to a valve of the
slide valve class, forms a typical illustration of the mode of carrying the said
invention into effect.
The valve proper is formed as a rectangular, or other suitably shaped ring, closed
at the top, but the said top is preferably sunk below the top edges of the ring. The
bottom edges bear and work upon the valve chest face in the usual way.
In the valve chest cover is a cylindrical opening, immediately over the centre of
and perpendicular to the valve chest face. This opening contains a piston, packed
with a cup leather, or in any other suitable way. The lower end of this piston
terminates in, or has affixed to it a plate having a true face formed on its under side,
and the said face bears upon the top edges of the valve, which are also brought to a
true face, parallel with the bottom edges.
The water pressure in the valve chest is exerted on both sides of this plate, but
the area occupied by the piston on its upper side being slightly less than the area
occupied by the valve on its under side, the valve is pressed against its face, by the
pressure on the small area representing the difference between the above areas.
The valve is therefore not in absolute balance, but these areas are so proportioned that
only just enough pressure is exerted upon it to ensure a proper working contact,
while it is relieved from the heavy injurious pressure before mentioned.
The above described cylindrical opening is closed by a cover, having a small
central cylindrical cavity, provided with a suitably packed piston, the lower end of
side of this small
which bears upon the centre of the piston aforesaid.
piston is in communication with the pipe leading from the valve chest to the
The
upper

page_text: hydraulic machine, or with the cylinder of the said machine, by means of a small
pipe, or a bye pass passage, and the underside is open to the space between the
pistons, which said space, by means of an aperture in the valve chest cover, com-
municates with the atmosphere.
The effect of this arrangement is, that when pressure is admitted to the valve chest
from the main, or supply pipe the valve is held to its face by the differential pressure
on the aforesaid plate, and when the valve is moved to admit pressure to the
hydraulic machine, an additional pressure is applied to the valve through the
medium of the said small piston, and in the event of the pressure in the supply pipe
suddenly ceasing, through bursting of the main, or other cause and the differential
pressure on the plate therefore ceasing, the valve is nevertheless held to its face by
means of the pressure on the said small piston, which pressure is not affected by the
release of pressure in the main, therefore in the case of a lift, crane, or other like
machine, the valve can be operated in the usual way to stop its descent, or permit
the same to take place under perfect control.
Any water which may pass either of the pistons above described, will escape into
the atmosphere through the aperture before mentioned in the valve chest cover.
Under certain conditions, as for example the sudden admission of water at pressure
to the valve chest when it is empty, there is a possibility of water getting between
the upper edges of the valve and the aforesaid plate, which would have the effect of
destroying the action of the large and small pistons and reducing the valve to the
condition of an ordinary unbalanced slide valve. To provide against such con-
tingency, the following arrangements may, if desired, be employed. Thus, a light
spring may be placed between the top of the large piston and the cover, giving
sufficient pressure upon the piston to keep the said plate and valve always in contact.
As such spring will not be in constant motion and will be away from the water, it
cannot deteriorate, and it may, if desired, be placed in a cavity in the top of the
piston, filled with oil.
As an alternative a 3-way cock may be fitted to the small pipe leading to the top
of the little piston, to provide a communication between such piston and the supply
main beyond the stop valve, which admits pressure to the valve chest. In operation,
such communication could, by means of the said 3-way cock, be established
before opening the stop valve, thus ensuring the large piston being forced down on
the valve before the admission of the pressure. After such admission the 3-way
cock is turned to its normal position. If desired, arrangements may be provided,
whereby the stop valve cannot be opened till the 3-way cock has been first turned, as
above described, while the slide valve cannot be operated till the said cock is turned
back.
of
to the
As a further alternative, the top of the large piston aforesaid, may be provided
with a flange, or enlargement working practically watertight in an enlargement of
the cylindrical opening in the valve chest cover, and an aperture be provided through
the centre of the piston. The effect being, that if on the admission
valve chest, the plate is not down on the
valve, or is forced off by the suddenness of the admission, the water gains immediate
access to the top of the piston and forces it down. The water thus admitted above
it, subsequently leaks off by a small aperture in the side of the cover, which is just
exposed when the piston is down in its correct position.
pressure
In the case where a valve is employed in connection with a machine, such for
example as a hydraulic engine, or motor, where sudden cessation of pressure merely
results in the stoppage of the machine, the small piston aforesaid may be omitted
and the large balancing piston only employed, while in a case where it is necessary
to have control of the machine, on bursting of a main, though it may not be thought
necessary to balance the valve, the small piston only may be employed.
Dated this 17th day of June 1897

page_text: Improvements in or connected with Valves for Hydraulic Machines.
I, REGINALD EMPSON MIDDLETON, of 17, Victoria Street, Westminster, in the
County of Middlesex, Civil Engineer, 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:-
The said invention relates to the construction of the valves employed for starting,
stopping, or otherwise regulating the working of hydraulic machines. It applies
more particularly to valves of the "slide valve" class, but may also be used in
connection with other kinds, such for example as rotary valves.
The ordinary slide, and some other forms of valve employed for the above des-
cribed purposes, are unbalanced, and the heavy pressures under which they gener-
ally work, soon cause deterioration of the faces and consequent leakage, while in
the event of the sudden cessation of the water supply, from the bursting of the main,
or other cause, such valves are liable to leave their faces, and the machine, to which
they are connected, cannot then be controlled.
In the case of a lift, or crane, such failure of the valve may cause serious damage,
as the lift-cage, or load will descend, without the possibility of any check being
applied.
The main objects of the present invention are to remedy these defects, by provid-
ing efficient means for balancing the valve and for automatically holding it to its
face, not only in the event of sudden failure of the water supply, but under all other
conditions of working.
The accompanying four sheets of drawings, which form part of this Specification,
illustrate the application of the invention to valves of the "slide" and "rotary
class, and form typical illustrations of the mode of carrying the said invention
into effect.
In the said drawings, in which similar letters of reference denote similar parts
throughout:
Fig. 1 is a side elevation,
Fig. 2 is a plan, and
Fig. 3 is a cross-sectional elevation through A, A, in Figs. 1 and 2, of a hydraulic
slide valve, constructed in accordance with one mode of applying the said invention.
Fig. 4 is a plan of the balancing piston and valve detached, through a a in Fig. 3.
Fig. 5 is a cross-sectional elevation, similar to Fig. 3, shewing a modification.
Fig. 6 is a side elevation, and
Fig. 7 is a plan, shewing an alternative modification.
Fig. 8 is a cross sectional elevation of a slide-valve, shewing a balancing arrange-
ment only, and
Fig. 9 is a similar view, shewing an automatic pressure arrangement only.
Fig. 10 is a cross-sectional elevation, similar to Fig. 3, shewing a slight modifica-
tion in the mode of construction.
Fig. 11 is a plan, and
Fig. 12 is a cross-sectional elevation, through 66 in Fig. 11, of a hydraulic rotary.
valve, constructed in accordance with a mode of applying my invention.
Fig. 13 is a plan of the valve detached.
The bottom
Referring first to Figs. 1 to 4, B is the slide valve, of rectangular shape, closed at
the top B¹, the said top being sunk below the upper edges of the valve.
edges bear and work upon the valve chest face C, in the usual way.
In the valve chest cover D, is a cylindrical opening E, immediately over the centre
of, and perpendicular to the valve chest face C. This opening contains a piston F,
packed with a cup leather F¹, or in any other suitable way. The lower end of this

page_text: piston F terminates in, or has affixed to it a rectangular plate F2, having a true face
formed on its under side, parallel with the valve chest face C, and the said face bears
upon the top edges of the valve B, which are also brought to a true face, parallel
with the bottom edges.
The water pressure in the valve chest is exerted on both sides of this plate F2, but
the area occupied by the piston F, on its upper side, being less than the area occupied
by the valve B, on its under side, as shewn clearly in Fig. 4, the said valve is pressed
against its face C, by the pressure on the area representing the difference between the
above areas.
The valve is therefore not in absolute balance, but these areas are so
proportioned that only just enough pressure is exerted upon it, to ensure a proper
working contact, while it is relieved from the heavy injurious pressure before
mentioned.
The cylindrical opening E is closed by a cover H, having a small central cylindri-
cal cavity H, axial with the opening E, and provided with a suitably packed
piston J, the lower end of which bears upon the centre of the piston F.
The upper end of this piston J, is, by means of the passage H2, and small pipe I,
in communication with the pipe L, leading from the valve chest to the hydraulic
machine, while the lower end is open to the space M, between the pistons.
If preferred, the pipe K may be connected to the cylinder of the hydraulic machine,
or in place of such pipe, a bye-pass passage may be employed, formed in the covers
and body of the valve chest."
The effect of this arrangement is, that when pressure is admitted to the valve chest
from the main, or supply pipe N, the valve B is held to its face by the differential
pressure on the plate Fa, and when the valve is moved to admit pressure to the
hydraulic machine, an additional pressure is applied to the valve through the
medium of the small piston J, and in the event of the pressure in the supply pipe N
suddenly ceasing, through bursting of the main, or supply pipe, or other cause,
and the differential pressure on the plate F2 therefore ceasing, the valve is neverthe-
less held to its face by means of the pressure on the small piston J, which pressure is
not affected by the release of pressure in the main, or supply pipe, therefore, in the
case of a lift, crane, or other like machine, the valve can be operated in the usual way.
to stop the descent of the lift cage, or load, or permit the same to take place under
the usual control.
Any water which may pass either of the pistons F or J, will escape into the
atmosphere, from the space M, through an aperture M¹.
Under certain conditions, as for example the sudden admission of water at
pressure to the valve chest when it is empty, there is a possibility of water getting
between the top of the valve B and the underside of the plate F, which would have
the effect of destroying the action of the pistons F and J, and reducing the valve to
the condition of an ordinary unbalanced slide valve." To provide against such
contingency, one, or other of the following arrangements are employed. Thus, a
helical spring P, see Fig. 5, may be placed within an annular recess P¹ in the
cover H, and bear upon the top of the piston F, with sufficient pressure to keep the
plate F and valve B always in contact. As such spring will not be in constant
motion and will be away from the water, it cannot deteriorate, and as an alternative
arrangement, it may be placed in an annular recess in the top of the piston F, filled
with oil.
In place of a spring, a 3 way cock Q, see Figs. 6 and 7, may be fitted to the small
pipe K leading to the top of the little piston J, to provide, by means of a pipe R, a
communication between such piston and the supply main N beyond the stop valve S,
which admits pressure to the valve chest. In operation, such communication could,
by means of the 3 way cock Q, be established before opening the stop valve S, thus
ensuring the pistons F and J being forced down on the valve before the admission of
pressure within the valve chest. After such admission the 3 way cock would be
turned to its normal position, to establish communication between the piston J and
the pipe L, or cylinder of the machine. If desired, arrangements may be provided,
whereby the stop valve S cannot be opened till the 3 way cock has been first turned,

page_text: as above described, while the slide valve B cannot be operated till the said cock is
turned back. An arrangement to fulfil the latter condition is shewn in Figs. 6 and 7.
This consists of a bar T, fixed by its downwardly projecting ends to the spindle V of
the slide valve, so that it is parallel with and moves as one piece with the said spindle.
Q is the hand wheel operating the 3 way cock Q, having a notch or slot in its
periphery through which the bar T can slide. There is also a notch T in the said
bar, to receive the edge of the hand wheel Q¹. Now when the parts are in the
position shewn in Fig. 7, the 3 way cock can be moved to admit pressure from the
main N beyond the stop valve S, and the valve B is then locked, because the notch
in the wheel Q is not opposite the bar T, but when the 3 way cock is turned back to
its normal position, the said notch is opposite the said bar, and the slide valve can be
operated, the bar T in its turn, preventing movement of the 3 way cock, until again
in the position shewn in Fig. 7.
•
In practice however, I prefer to employ an arrangement shewn in Fig. 3. In this
case the top of the piston F is provided with a flange, or enlargement W, working
practically watertight in an enlargement of the cylindrical opening E in the valve
chest cover D, and an aperture X is provided through the centre of the piston F.
The effect being that if on the admission of pressure to the valve chest, the plate F
is not down on the valve, or is forced off by the suddenness of the admission, the
water gains immediate access to the enlarged top of the piston F, and so forces it
down. The water thus admitted above it, will subsequently leak past it and escape
by the small aperture M¹ aforesaid, which in this case is placed below the flange W.
A cross groove X' is formed in the bottom of the piston J to ensure free access of
the water to the top of F.
In the case where a valve is employed in connection with a machine, such for
example as a hydraulic engine, or motor, where sudden cessation of pressure merely
results in the stoppage of the machine, the small piston J may be omitted, and the
large balancing piston F, only employed. Such an arrangement is shewn in Fig. 8,
the piston F being similar to that shewn in Fig. 3, and provided with an enlarge-
ment W and aperture X, for the purpose above described.
In certain other applications, where it is necessary to have control of the machine,
on bursting of the main or supply pipe, though it may not be thought necessary to
balance the valve, the small pressure piston J, only is employed, and such arrange-
ment is shewn in Fig. 9.
Here the piston J bears upon, or has attached to its lower end a plate J¹, through
which its pressure is transmitted to the valve B.
Although the pistons F and J, have so far been described as separate from each
other, they may be constructed in one piece, as shewn in Fig. 10, and in this and the
previous figures, the piston F is fitted with a detachable ring, or annular piece F³, to
enable its cup leather to be fitted in place.
Forming the two pistons in one, has the advantage that the small piston then acts
as an efficient guide to the large piston, and prevents the possibility of the latter
canting or jamming in its cylinder.
The space on the top of the valve B may also be omitted, and the said valve formed
with a solid continuous top surface.
In the application of the invention to a hydraulic valve of the rotary class, as
.shewn in Figs. 11, 12 and 13, B is the valve, having an inlet port c and an exhaust
port d, and capable of rotation about the pivot e upon the valve chest face C.
The upper part of the valve is reduced in diameter to receive a loose ring B³,
which seats against the valve chest cover D, the joint being made by a washer B³, in
the usual way.
The valve, as will be seen from its form, is practically balanced,
there being only enough pressure upon the two parts BB, to keep them to their
seats.
Formed in one piece with, or affixed to the part B is a spindle f, passing through a
stuffing-box 9: and serving as the means of communicating motion to the valve.
In the valve chest cover is a cylindrical cavity H¹, and an enlargement J of the
spindle f, fitted with a cup leather, or other suitable packing, works water-tight in

page_text: the said cavity. Pressure from the pipe L, leading to the cylinder of the hydraulic
machine, is admitted to the upper end of the piston J by the pipe K, so that on
sudden cessation of pressure within the valve chest, from the bursting of the main, or
other cause, the valve B is kept to its face by means of the pressure on the piston J.
Any water which may leak past the said piston, or the ring B³, will escape by the
passages
h and i into the exhaust port d.
The invention may be applied in a similar manner to the rotary valve of a
3 cylinder, or other like hydraulic engine.
+
The above examples illustrate the main features of the invention, but modifications
may be made in the arrangement, where necessary, to adapt the invention to d
variations in the pattern or construction of the valve to which it is to be applied,
provided that in all cases the essential principles of the invention be retained.
Having now,particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I claim
is:-
1. In a hydraulic slide valve, in combination, a piston F with plate F³, a loose
ring F3 with enlargement W, a passage X, and aperture M', substantially as and
for the purposes herein set forth.
2. In a hydraulic slide-valve, in combination, a piston J, and a pipe K or other
like passage, substantially as and for the purpose herein set forth.
3. In a hydraulic slide-valve, in combination, a piston F with plate F2, a piston J,
and a pipe K or other like passage, substantially as and for the purposes.herein set
forth.
4. In a hydraulic slide-valve, in combination, a piston F with plate F2, a loose
ring F3 with enlargement W, a passage X, an aperture M¹, a piston J, and a pipe K
or other like passage, substantially, as and for the purposes herein set forth.
5. In a hydraulic slide valve, in combination, a piston F with plate F2, a piston J
.formed in one piece with or affixed to said piston F, and a pipe K or other like
passage, substantially as and for the purposes herein set forth.
6. In a hydraulic slide valve, in combination, a piston F with plate F³, a loose
ring F3 with enlargement W, a passage X, an aperture M¹, a piston J formed in one
piece with or affixed to said piston F, and a pipe K or other like passage,
substantially as and for the purposes herein set forth.
7. In a hydraulic rotary valve, in combination, a piston J, and pipe K. or other like
passage, substantially as and for the purpose.herein. set.forth.
8. A hydraulic valve, constructed and operating in the manner and for the
purposes, substantially as herein set forth with reference to Figs. 1, 2, 3 and 4. of
the accompanying drawings.
9. A hydraulic valve, constructed and operating in the manner and for the
purposes, substantially. as herein set forth with reference to Fig. 8 of the accompany-`
ing drawings.
10. A hydraulic valve, constructed and operating in the manner and for the
purposes, substantially as herein set forth, with reference to Fig. 9 of the accompany-
ing drawings.
4
11. A hydraulic valve, constructed and operating in the manner and for the 4
purposes, substantially as herein set forth, with reference to Fig. 10 of the
accompanying drawings.
12. A hydraulic valve, constructed and operating in the manner and for the
purposes, substantially as herein set forth with reference to Figs. 11, 12 and 13 of
the accompanying drawings.
Dated the 15th 1e of Manch
1000
5
AMBROSE MYALL,
2, Lancaster Place, London, W.C.,
Agent for the Applicant.