IMPROVEMENTS IN SAFETY OR ESCAPE VALVES
Year: 1876

page_text: LETTERS PATENT to Carl Friedrich Heinrich Bollé, of the City of Manchester,
in the County of Lancaster, Engineer, for the Invention of "IMPROVEMENTS IN
SAFETY OR ESCAPE VALVES."
Scaled the 5th June 1877, and dated the 14th December 1876.
PROVISIONAL SPECIFICATION left by the said Carl Friedrich Heinrich Bollé
at the Office of the Commissioners of Patents on the 14th December 1876.
CARL FRIEDRICH HEINRICH BOLLE, of the City of Manchester, in the County of
Lancaster, Engineer. "LMPROVEMENTS IN SAFETY OR ESCAPE VALVES."
The object of my Invention is a directly weighted safety valve of the equilibrium
class, which will open a wide orifice for the escape of the steam or other elastic
fluid when the pressure of such elastic fluid exceeds a limit fixed upon, and my
Invention consists in an improved combination and arrangement, namely:-I prefer
to form the casing of the valve having a passage to communicate with the boiler,
and an outlet escape passage from the valve, of cast iron, which is bored out to
receive a bush of brass forming a double seating for a valve having two cone facings
of the equilibrium class, which is made with a hole through its centre or axis,
through which hole a spindle passes, which has an inverted valve facing or cone at
its lower end that fits a seating upon the lower side of the hole through the
equilibrium or escape valve. The upper end of the spindle has a plug screwed upon
it, the lower edge of which forms a flat valve facing, that rests upon a projecting
flange in a bush secured in a tube forming part of the casing of the valve. Upon
the upper outside end of the spindle a hat-shaped piece is suspended, the inside of
the part corresponding to the crown of the hat resting upon the end of the spindle,
while the part corresponding to the brim of the hat serves to support the ring
weights used to keep down the valve. While the pressure of the steam is below
the limit fixed upon, the small valve at the upper end of the spindle is closed, and
that at the lower end is open, allowing the steam to pass through the hole in the
equilibrium or escape valve, and act upon the upper side of it, which is a little
larger in area, so that the pressure will keep the escape valve shut; but when the
pressure increases above the limit fixed upon the small valve at the upper end of
the spindle and weights are lifted, and this draws up the spindle so that the head

page_text: or valve at its lower end closes the hole in the escape or equilibrium valve; this
shuts off or diminishes the supply of steam to the upper side of the escape valve, as
a small part of that left above the escape valve is passing away through the small
valve at the upper end of the spindle, and as the latter valve exposes a larger area
after it has opened, this extra lifting pressure and that upon the lower end of the
spindle acts to open the escape valve to its full extent.
A part of the weight is suspended on the ends of the pins fixed in the casing of
the valve when the escape valve is closed, but when fully opened the weight will
rest upon the upper surface of the other weights, and will help to close the valve
when the pressure of the escaping steam or elastic fluid has sufficiently diminished.
There may be a small valve facing to prevent the small escape of steam past the
plug at the upper end of the spindle when the valve has lifted, and to limit the rise
of the spindle, and there may be projections from the spindle which will only just
be clear of the upper side of the escape valve when the latter and the spindle are in
their lowest positions, the projections acting in that case to help to close the escape
valve when the spindle is forced down by the weights on the pressure being dimin-
ished to the required extent.
The casing of the valve limits the rise of the escape valve, and when the
spindle and escape valve are at their highest, and the latter rises higher than the
former the steam can pass through the escape valve to its upper side.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Carl Friedrich Heinrich Bollé in the Great Seal Patent Office on the
5th June 1877.
CARL FRIEDRICH HEINRICH BOLLE, of the City of Manchester, in the County of
Lancaster, Engineer. "IMPROVEMENTS IN SAFETY OR ESCAPE VALVES."
The object of my Invention is a directly weighted safety valve of the equilibrium
class, which will open a wide orifice for the escape of the steam or other elastic fluid
when the pressure of such elastic fluid exceeds a limit fixed upon, and my Invention
consists in an improved combination and arrangement which will be most readily
described by reference to the accompanying Drawings.
Fig. 1 is a vertical section through the axis of the valve; Fig. 2 is an outside
elevation; Fig. 3 is a plan section on the line A, B, Fig. I; and Fig. 4 is a plan
with cap part of the valve casing removed.
a is the lower part, and a¹ is the upper part of the valve casing, the latter fitting
and being secured to the former by bolts a*, as shown; a² is the flange for securing
the valve casing to the boiler, pipe, or other vessel, and as the flange for the escape
pipe where used; b is a bush in the casing forming the lower seating of the double
valve; b, another bush forming the upper seating of the double valve, this bushi
having projections be parallel to the axis of the valve to act as guides to the double
valve c. Through the axis of the valve c there is a hole for the spindle d of the
valve to pass through, which spindle has a shoulder upon it that acts as a valve
to close the hole through the equilibrium valve when the spindle rises. The spindle
has grooves in it, as shown in the plan section, Fig. 3, so that the steam or elastic
fluid can pass through the valve c to the space above, and keep it down on its
seating. The upper end of the spindle d passes through a bush e secured by a
screw in the upper casing a¹, and the end of the spindle has a long collar & with a
valve facing secured upon it by a ring nut d², as shown. Upon this collar da hat-
shaped weight carrier freats to carry the moveable ring weights f¹. When the
spindle d is pressed down by the weights to the lowest position the valve facing on
the collar d' rests upon a seating on the bush e.
I prefer to place a spring g round the spindle d, as shown, abutting against the
collar d' at its upper end, and at its lower end against a loose collar d³ on the
spindle, and exerting some pressure (say, about one-twelfth of the load on the

page_text: valve) to help to close the equilibrium valve c after it has been opened by an
excess of pressure when the pressure has sufficiently diminished. The diameter
of the lower end of the spindle d and the collar d'are about the same, and the lower
end of the spindle passes through a hole in the plate of metal h, secured by bolt
studs to the valve casing a, as shown. This plate h is perforated all over with
small holes, so that the steam or elastic fluid passing out through the valve will be
more divided, and the pressure of the steam or elastic fluid acting upon the end of
the spindle will be less likely to be affected by the current or flow of the escaping
elastic fluid.
Instead of the disc or plate being secured on stud bolts, as shown, a diaphragm
may be cast in the casing a, with a central hole for the spindle to pass through,
and slit holes or openings for the steam or elastic fluid to pass through near the
sides of the casing.
The action of the valve is as follows:-When the pressure of steam or elastic
fluid acting upon the area of the spindle or the collar d' is sufficient the spindle risos,
and the shoulder or valve d' upon the spindle comes in contact with the under side
of the valve c, and closes it; then the steam above the valve c escapes past the
collar d', which removes the pressure from the upper side of the valve c, which is
then forced up until it comes against the casing a¹, which forms a stop. The prin-
cipal part of the escaping steam or elastic fluid passes out between the lower valve
facing and its seating (b).
When the pressure has diminished a little below the pressure at which the valve
opens then the weights fand f1 force down the spindle d, and the spring g acts
along with the weight of the valve (c) to close it, assisted by the increase of pressure
above the valve c.
I have now particularly described the nature of my said Invention, and the mode
of carrying the same into effect, and claim as my Invention, a spindle and double or
equilibrium valve combined and arranged with the other parts, substantially as
herein-before described and illustrated by the accompanying Drawings.
In witness whereof, I, the said Carl Friedrich Heinrich Bollé, have hereunto
set my hand and seal, this Second day of June, in the year of our Lord One
thousand eight hundred and seventy-seven.
AUT
RAT15
CARL F. H. BOLLÉ. (LS.)