IMPROVEMENTS IN STOP VALVES
Year: 1881

page_text: LETTERS PATENT to John Dewrance and George Henry Wall, both of 176,
Great Dover Street, Borough, in the County of Surrey, for an Invention of
"IMPROVEMENTS IN STOP VALVES."
PROVISIONAL SPECIFICATION left by the said John Dewrance and George
Henry Wall at the Office of the Commissioners of Patents on the 15th January
1881.
JOHN DEWRANCE and GEORGE HENRY WALL, both of 176, Great Dover Street,
Borough, in the County of Surrey. "IMPROVEMENTS IN STOP VALVES."
This Invention has for its object improvements in stop valves.
We construct a cage (two rings connected by bars), and on the inside of the
lower ring we form the seat of the valve; the outside of the same ring we arrange
to form a tight joint on the diaphragm of the stop valve. The cage is forced down
on to the diaphragm by the upper ring either by screwing it into the body or by
arranging it so that the cover will put sufficient pressure upon it. When under
steam the expansion of the cage itself assists in making the joint on the
diaphragm.
By this arrangement we can renew the seating when necessary without fear of
straining it.
Sometimes we arrange the lower ring of the cage to fit into a cavity formed for
it in the diaphragmn, and an inner cage, which we call the valve, fits inside the
outer cage. The hole in the diaphragm is bored to fit the valve.
Rings of asbestos packing are provided at both ends of the outer cage; they
surround the valve and are compressed by a gland.
When the upper ring of the valve, which is broad, is opposite these packings the
way through the stop valve is closed, but when the bars of the valve are opposite
the bars of the outer cage and between the two packing rings the steam or fluid
passes through the bottom of the valve and through the bars of both the valve and
the cage.
The depth of the lower ring of the cage is such that when the upper ring of the

page_text: valve leaves it before it opens a passage for the steam the packing is covered by the
lower ring of the valve, so that the packing is never exposed.
Sometimes we make the cage solid with the cover and dispense with the upper
packing ring, and we then apply a stuffing-box to the spindle.
The nut and stuffing box we arrange as follows:-We form a cavity in the cover
and screw it to take the stuffing nut. When the nut is screwed down tight we bore
and screw a hole through both the nut and the cover to fit the valve spindle; this
thread is the same pitch as that in the packing cavity.
Sometimes we make these stuffing boxes with the packing inserted at the side
and compressed by screws and with the screw thread passing through the top and
bottom of the box, which in this case are in one piece.
Either of these arrangements secures extra length of thread with facility for
greasing it while at work, and the stop valve is more compact.
These stuffing boxes are applicable to all forms of stop valves.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Dewrance and George Henry Wall in the Great Seal Patent
Office on the 14th July 1881.
JOHN DEWRANCE and GEORGE HENRY WALL, both of 176, Great Dover Street,
Borough, in the County of Surrey. "IMPROVEMENTS IN STOP VALVES."
This Invention has for its object improvements in stop valves.
We construct a cage (two rings connected by bars), and on the inside of the lower
ring we form the seat of the valve; the outside of the same ring we arrange to form
a tight joint on the diaphragm of the stop valve. The cage is forced down on to
the diaphragm by the upper ring, either by screwing it into the body or by
arranging it so that the cover will put sufficient pressure upon it. When under
steam the expansion of the cage itself assists in making the joint on the
diaphragm.
By this arrangement we can renew the seating when necessary without fear of
straining it.
Sometimes we arrange the lower ring of the cage to fit into a cavity formed for
it in the diaphragm, and an inner cage, which we call the valve, fits inside the outer
cage. The hole in the diaphragm is bored to fit the valve.
Rings of asbestos packing are provided at both ends of the outer cage; they
surround the valve and are compressed by a gland.
.
When the upper ring of the valve, which is broad, is opposite these packings, the.
way through the stop valve is closed, but when the bars of the valve are opposite
the bars of the outer cage and between the two packing rings the steam or fluid
passes through the bottom of the valve and through the bars of both the valve and
the cage.
The depth of the lower ring of the cage is such that when the upper ring of the
valve leaves it before it opens a passage for the steam the packing is covered by the
lower ring of the valve, so that the packing is never exposed.
Sometimes we make the cage solid with the cover and dispense with the upper
packing ring, and we then apply a stuffing box to the spindle.
The nut and stuffing box we arrange as follows:-We form a cavity in the cover
and screw it to take the stuffing nut. When the nut is screwed down tight we bore
and screw a hole through both the nut and the cover to fit the valve spindle; this
thread is the same pitch as that in the packing cavity. Sometimes we make
these stuffing boxes with the packing inserted at the side and compressed by screws
and with the screw thread passing through the top and bottom of the box, which in
this case are in one piece.
Either of these arrangements secures extra length of thread with facility for
greasing it while at work, and the stop valve is more compact.
These stuffing boxes are applicable to all forms of stop valves.
In order that our said Invention may be most fully understood and readily
carried into effect, we will proceed to describe the Drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.

page_text: hereinafter more fully described. Our novel renewable seating for the valve is a
cage, consisting of two rings e and e¹ connected by the bars e; the lower ring e
fits accurately into the opening in the diaphragm a³, and the bearing surface for
the valve is truly formed within it. The upper ring e¹ of the renewable seating
is, as here shewn, made to screw into the socket prepared upon the shell to receive
the stuffing box.
A plan of the renewable seating is shown at Figure 2; ex are notches in the
upper ring e¹ to receive the tool by which the seating is screwed down to its place
to fit tightly against the diaphragm, and by which it can also be removed when
it becomes unserviceable.
Figure 3 is a longitudinal section of the description of stop valve known as a
check valve. The shell and the renewable cage seating are the same as in Figures 1
and 2, but the screw and stuffing boxes are replaced by a simple cap in which
there is a guide for a stem formed upon the valve.
Figure 4 is a longitudinal section of another form of check valve to which we
apply our renewable cage seating. The cage although somewhat different in form
is similar to that already described. The shell in this form of check valve has the
inlet passage immediately beneath the valve; we make the seating longer to form
a guide for the valve.
Figure 5 is a section on the line 1, 1, in Figure 4.
Figure 6 is a longitudinal section of a stop valve of larger size; Figure 7 is an
end elevation, and Figure 8 a section on the line 1, 1, in Figure 7. The con-
struction of this stop valve clearly appears from the Drawing; it differs from the
stop valve shown by Figure 1 principally in that the, renewable cage seating is
not screwed into the shell, but is made of such a length that the cover (which in
this case is bolted on) keeps it in its place. Figure 9 is a plan of the valve seating.
The cover carries a screwed stuffing box, hereinafter described, and the screw passes
through it.
Sometimes we interpose a ring of packing between the renewable cage like
seating and the cap or cover, in the manner shown in Figure 10.
Figure 11 is a longitudinal section of a stop valve, in which we employ, together
with an outer or fixed cage, an inner cage which serves as the valve.
Figures 12, 13, and 14 are sections of the same stop valve taken on the lines
1, 1, and 2, 2, and 3, 3, in Figure 11 respectively.
a is the shell; a', the diaphragm; and b is the inner cage serving as the valve;
c is the screw by which motion is imparted to the valve, it has a hand wheel keyed
to the upper end of its stem. There is a button at the lower end of the screw c
which is received into a cavity in the cage valve b in which it fits loosely, it is
retained by a screw ring. The screw works through a nut fixed upon the
cover d, as in this construction a stuffing box is not required; e is the outer cage,
it has a ring of packing both below and above it, and this packing being compressed
by the cap comes into fluid tight contact with the cage valve b. In Figure 11 the
stop valve is shown open, and the fluid is able to pass freely between the bars of
both cages, and so from one side of the diaphragm a¹ to the other. In screwing
the valve down the flow will be almost completely stopped when the bars of the
two cages cease to be opposite to each other, but a perfect closing will not be
effected until the bars of the cage valve b have passed beneath the lower ring of
packing. Thus the current of the fluid is cut off before the packing is uncovered,
and there is no danger of the packing being displaced.
Figure 1 shows one of the ways in which, in accordance with our Invention, we
make a screwed stuffing box for stop valve requiring a stuffing box. In this Figure
dx is the stuffing nut, whilst in construction it is screwed down tight, then the
thread to receive the screw c is cut right through it and also the bottom of the box.
This screw must have the same thread as that by which the stuffing nut d* itself
screws into the stuffing box, and then in screwing the stuffing nut down on the
packing the thread within the stuffing nut will remain true with the thread in the
bottom of the stuffing box.

page_text: Figure 15 is an elevation partly in section of a stop valve, and shows another
way of forming its stuffing box in accordance with our Invention. Here the cover
is screwed right through and packing is applied by apertures at the side, and is
compressed by plugs a screwed in, as the Drawing clearly indicates. Figure 16
is a section on the line 1, 1, in Figure 15. The packing which we employ is
asbestos.
This stuffing box is essentially similar to that shown in Figure 6. The com-
pressing plugs also, as here shown, take the form of glands and are drawn to
their places by external screws.
Having thus described the nature of our said Invention, and the manner of
performing the same, we would have it understood that we claim,-
First. Our renewable cage like valve seating for stop valves and the methods
of fixing same, substantially as described in respect to Figures 1, 2, 3, 4, 5, 6, 9,
and 10 of the Drawings.
'
Second. Our double cage stop valve, substantially as described in respect to
Figures 11, 12, 13, and 14 of the Drawings.
Third. In our double cage stop valve so proportioning the cages that the flow is
cut off before the packing is uncovered, substantially as described.
Fourth. The method of forming the stuffing boxes of stop valves, substantially
as described in respect to Figure 1 of the Drawings.
Fifth. The method of forming the screwed stuffing boxes for stop valves, sub-
stantially as described in respect to Figures 15 and 16 of the Drawings.
In witness whereof, I, the said John Dewrance, have hereunto set my hand
and seal, this Fourteenth day of July, in the year of our Lord One
thousand eight hundred and eighty one.
ΤΑΥΤΑΣ
TCA לתת
JOHN DEWRANCE.
(1.S.)