Improvements in Hydraulic Valves.
Year: 1898

page_text: Date of Application, 8th Feb., 1898
Complete Specification Left, 8th Nov., 1898-Accepted, 28th Jan., 1899
Improvements in Hydraulic Valves.
I, JOHN FIELDING, of Upton Saint Leonards, in the County of Gloucester,
Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to an improved hydraulic piston valve of the kind in
which packing leathers act as the valve edges.
My objects are to simplify and cheapen the construction of such valves, to
facilitate the renewal and examination of the packing leathers and to reduce
their wear and tear.
According to my invention the valve consists of an outer chambered body,
provided with suitable branches, for connection to the inlet and outlet pipes, an
inner cylinder or bush which may be permanently fixed inside the valve body.
A working piston consisting of a central bolt upon which are threaded the pack-
ing leathers which may be all of one pattern, to hold these leathers in their
proper positions, collars are interposed of suitable length.
In the outer body there are four annular chambers separated from each other
by pressure tight joints made by shoulders upon the inner bush. Starting from
one end say from left to right the first and third chambers are connected with the
cylinder of the machine to be worked, the second is that at which the pressure
enters, whilst the fourth is the exhaust chamber connected to the escape pipe.
Annular ports, preferably formed by drilling a number of small holes, are
formed in the inner bush opposite the second and third chambers, a similar
passage is formed opposite the first chamber, but in this case the holes may be
larger and fewer in number, the fourth chamber may be made to open to one end
of the inner bush which may terminate about midway between the third and
fourth chambers.
The first and third chambers may be connected by a side passage and to the
cylinder by a pipe common to both, or separate pipes may be used which in
certain cases is an advantage.
Four packing leathers are held upon the central bolt by means of the distance
pieces or collars already mentioned, the two leathers to the left are placed with
their lips facing to the right, the other two which are to the right have their
lips facing to the left, thus the lips of one pair face the lips of the other, all
facing towards the centre. The first leather, counting from left to right acts
as a packing to prevent leakage to the outside of valve and it passes over no
port, the second is the leather which controls the flow of pressure from the inlet
chamber to the working cylinder of machine and in working it passes over the
inlet passage holes.
The third prevents the leakage of water from the pressure inlet to the right
hand end of valve, and this like the first passes over no passage holes. The
fourth leather is that which controls the escape of the exhaust water from the
working cvlinder.
To admit pressure to the cylinder the valve piston is moved from left to right

page_text: and to exhaust it is moved from right to left. The position of the two con-
trolling leathers is such that they are perfectly protected from the flow of water
and their durability is thereby increased. The entire piston may be withdrawn
bodily by simply disconnecting it from the working lever, so that its examina-
tion is greatly facilitated.
A modification of such a valve may be used as a reducing valve, when con-
structed in the following manner.
A chambered external Body and internal fixed liner similar to that already
described, is used, but having only one inlet and one outlet branch.
The former communicates with an annular passage or port consisting of a ring
of small holes drilled through the liner, the outlet branch communicates with
another port which may be formed by a less number of larger holes giving
about an equal area to the other port.
The inner liner is bored to two diameters the inlet port being in the smaller
and the outlet in the larger bore.
There are three packing leathers upon the central spindle, the two outer pre-
venting external leakage whilst the central leather acts as a valve passing over
the small drilled holes for the purpose of opening or closing the passage.
A spring, fitted if desired with means of regulating its tension is connected
at one end to the outer body and at the other end to the valve piston. The
action of the spring is opposed to whatever hydraulic pressure may be acting
upon the annular area due to the difference between the two diameters to which
the liner is bored, the spring tending to opening the passage whilst the hydraulic
pressure tends to close it.
Such a valve is preferably used in conjunction with a pressure and exhaust
distribution valve provided with separate passages leading to and from the
machine cylinder. The reducing valve is placed in the passage leading to the
cylinder so that no obstruction is offered by it to the free exhaust of the waste
water.
Dated thi 5+1. 1
1
1000
Improvements in Hydraulic Valves.
I, JOHN FIELDING, of Belmont, Upton Saint Leonards, in the County of Glou-
cester, 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:-
My invention refers to an improved hydraulic piston valve of the kind in which
packing leathers act as valve edges.
My object is to simplify and cheapen the construction of such valves, to
facilitate the renewal and examination of the packing leathers, and to reduce
the wear and tear.
According to my invention the valve consists of an outer chambered body
provided with suitable branches for connection to the inlet and outlet pipes, an
inner cylinder or bush which may be permanently fixed inside the valve body.
A working piston consisting of a central bolt upon which are threaded the pack-
ing leathers which may be all of one pattern; to hold these leathers in their
proper positions collars are interposed of suitable length.
In the outer body there are four annular chambers separated from each other
by pressure tight joints made by shoulders upon the inner bush. Starting from

page_text: are
one end, say from left to right, the first and third chambers are connected with the
cylinder of the machine to be worked, the second is that at which the pressure
enters, whilst the fourth is the exhaust chamber connected to the escape pipe.
Annular ports preferably formed by drilling a number of small holes
formed in the inner bush opposite the second and third chambers, a similar
passage is formed opposite the first chamber, but in this case the holes may be
larger and fewer in number, the fourth chamber may be made open to one end
of the inner bush which may terminate about midway between the third and
fourth chambers.
The first and third chambers may be connected by a side passage, and to the
cylinder by. a pipe common to both, or separate pipes may be used which in
certain cases is an advantage.
Four packing leathers are held upon the central belt by means of the distance
pieces or collars already mentioned, the two leathers to the left are placed with
their lips facing to the right, the other two which are to the right have their
lips facing to the left, thus the lips of one pair face the lips of the other, all
facing towards the centre. The first leather counting from left to right act
as a packing to prevent leakage to the outside of valve and it passes over no
port, the second is the leather which controls the flow of pressure from the inlet
chamber to the working cylinder of machine, and in working it passes over the
inlet passage holes. The third prevents the leakage of water from the pressure
inlet to the right hand end of valve, and this, like the first, passes over no passago
holes, the fourth leather is that which controls the escape of the exhaust water
from the working cylinder.
To admit pressure to the cylinder the valve piston is moved from left to right
and to exhaust it is moved from right to left. The position of the two con-
trolling leathers is such that they are perfectly protected from the flow of water,
and their durability is thereby increased. The entire piston may be withdrawn
bodily by simply disconnecting it from the working lever, so that its examina-
tion is greatly facilitated.
DESCRIPTION OF THE DRAWING.
Fig. 1 shews a complete section of my improved valve with the piston in mid
position. Figs. 2 and 3 are supplementary views shewing the valve piston at
the two ends of its movement. 1 is the outer chambered body with branches 2, 3,
and 4 respectively to connect to the pressure pipe, exhaust pipe, and cylinder of
the machine to be operated, 5 is the inner cylinder or bush suitably held in
position with pressure tight joints between the several chambers of the outer
body.
6 is the central bolt upon which are threaded the packing leathers 7, 8, 9, 10
secured in their proper position by collars 11, 12, and 13, and the cap or nut 14,
15 is a stuffing box through which the solid end of the central bolt 6 works.
Whilst the pressure inlet and the exhaust branches each connect with one
chamber, the cylinder branch 4 connects with two chambers, one, 16, for the
passage of water into, and another-17-for the passage of water out of the
cylinder.
Referring to the leathers, 7 and 9 are simply packing leathers, the former to
prevent leakage to the outside of the valve, and the latter from the pressure
chamber to the cylinder chamber 17. Leathers 8 and 10 are the valve leathers
proper which control the admission and outlet of water.
In Fig. 1 the piston is in mid-position so that water cannot enter or escape
from the cylinder.
In Fig. 2 the piston is shewn moved to the right hand which has caused the
leather 8 to pass over the pressure inlet ports in the cylinder, thus allowing
water to flow into the chamber 16, and to the cylinder branch 4, at the same
5 time the leather 10 has moved further away from the exhaust port, and prevents
the escape of water to the exhaust chamber.

page_text: In Fig. 3 the reverse position of the piston is shewn, leather 8 having repassed
the pressure inlet port, and leather 10 has passed over the outlet port to permit
the escape of water from the cylinder.
.
Fig. 4 shews one method of securing the cover which holds the inner cylinder
or bush in position.
Figs. 5 and 6 shew to an enlarged scale the method preferably adopted in the
formation of the annular ports in cylinder, these consisting of a number of small
holes drilled in the walls of cylinder.
Having now particularly described and ascertained the nature of my said in-
vention, and in what manner the same is to be performed, I declare that what I
claim is:-
The arrangements and construction of a hydraulic piston valve substantially
as described.