Year: 1896

page_text: Date of Application (in United Kingdom), 12th Nov., 1896
Complete Specification Left, 10th Aug., 1897-Accepted, 16th Oct., 1897
We, ALCIDE GENARD and ALBERT GÉNARD, both of 212 Rue Lafayette, Paris, France,
Manufacturers do hereby declare the nature of this invention to be as follows::-
The essential part of this apparatus is that which closes the orifice by which the
steam makes its escape. In ordinary valves this piece takes the form of a conical
flap the surface of the flap is subjected to the pressure of the steam (the steam which
should escape when the valve opens). My valve has the distinguishing characteristic
that it is not exposed to any pressure from the steam escaping at the moment of its
opening; this effect is obtained by making the valve grooved or hollowed, thus giving
it the form of a hollow cylinder or rather of a bell; its edges rest on a seat as in an
ordinary valve, and, in this condition it would act as such, and the steam would
exercise its pressure on the inside of the bell. But close to the top of the bell, a
piston is placed forming a diaphragm with a rod attached on the valve-seat. This
piston, therefore, is fixed, it masks the top of the bell which is thus withdrawn from
the action of the steam filling the boiler and the lower part of the bell.
Under these circumstances, the bell-shaped valve tends neither to open nor to
shut by the pressure of the steam. The action is obtained by supplying the valve
with steam taken from right within the boiler by means of a passage pierced in the
rod of the diaphragm piston; this steam takes effect against the top of the fixed
piston and the top of the moveable bell. When the steam pressure equalises the
load or weight, the bell rises, its edges leave the seat and the steam escapes ;
notwithstanding the loss of stean, the top-inside of the bell receives integrally the
whole pressure of the steam which passes through the passage, the diaphragm piston
preventing it from escaping freely at the edges of the bell. It follows that the valve
support the same pressure, whether it is open or closed.
When the pressure falls in the boiler, the valve falls only as an ordinary one of
conical form. The opening of the valve, by an independent steam supply, allows the
valve to be used with other fluids besides steain, water for example.
The weight, which acts as an equilibrium to the pressure of the steam, is obtained
by the help of a spring enclosed within a casing; its tension may be regulated very
precisely by a fixed-screw device and this tension can be modified, firstly by the shape
of the working head of the screw, and secondly by a nut which limits the compression
of the spring. This limit cannot be exceeded without taking the whole valve to
pieces. The weight, however, may be obtained by means of a lever and counter-
weight, or by a weight acting directly on the valve, as in existing valves. The

page_text: essential object of the invention is the closing-piece of the escape-hole for the steam.
and this is not found in any valve used at the present time.
This valve is made in the form of a bronze cylinder C. The lower end is open, and
it terminates in a flange b, which allows of the valve being bolted to the boiler. The
cylinder is closed at the top by means of a lid fastened with bolts. In the lower part
of the cylinder, a conical seat S is cut, on which rests the bell-shaped valve E, which
is made of bronze; above this there is a spring R which is lodged in the upper part.
of the cylinder. Through the centre of the lid, a screw-threaded rod t passes,
occupying the axial part of the cylinder; the head of the screw appears as a button
on the lid and is worked with a special key. Within the cylinder the screw carries a
plate P with wing-like extensions preventing it from turning; this plate presses
upon the spring R.
When the screw is turned it causes the plate P to descend or to rise, according
to the direction in which it is turned, and in this way the spring is either tightened
or loosened. A nut e is placed on the screw-threaded rod, a little below the plate P,
limiting the play of the latter, so that the spring cannot be compressed beyond a
certain limit. The lower part of the periphery of the cylinder G is slightly grooved
or hollowed inside and bulged outside and forms an annular chamber pierced with
wide openings O, so that as soon as the valve E rises, the steam can escape freely.
Under the valve-seat, are cast-metal arms a, serving as a point of attachment to the rod
of the diaphragm piston L; the steam passes freely between the arins a. A slight
play is allowed around the diaphragm piston L in order that it may not rub against
the wall of the bell-shaped valve C. The top of the diaphragm piston is hollowed out
like a funnel, in order that the condensation water may not gather and falls back into
the boiler through the passage of the diaphragmn rod l.
The most important advantages of the valve may be thus summarised: The rise of
the valve is considerable, so that there is a maximum escape of steam as compared
with the valve passage.
The valve closes simultaneously with the ceasing of the alarm signal. The flap
is well guided and always falls straight back on its seat; there are no friction surfaces
exposed to the steam.
On the outside, these surfaces are much reduced and only serve to secure a
good guidance.
The valve operates with steam, compressed air or water indifferently.
The spring can be regulated with great exactness so that the valve will rise
directly the alarm sounds. The latitude of operation can be regulated just as
required.
The operation can only be modified by means of the special key which must not be
accessible to the stoker.
Dated this 11th day of November 1896.
L. DUVINAGE,
Agent for Applicants.
We, ALCIDE GÉNARD and ALBERT GÉNARD both of 212 Rue Lafayette, Paris,
France, Manufacturers, 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 :-
This invention has for its object a safety-valve for steam-boilers and other apparatus,
which are subjected to a high pressure of steam from water or other fluids. In the
drawing, filled with the Provisional Specification.

page_text: Tig
section
Fig. 2 a horizontal section on the line A B Fig. 1.
This valve is inade in the form of a bronze cylinder C. The lower end is open,
and it terminates in a flange b, which allows of the valve being bolted to the
boiler. The cylinder is closed at the top by means of a lid fastened with bolts. In
the lower part of the cylinder, a conical seat S is cut, on which rests the bell-shaped
valve E, which is made of bronze; above this there is a spring R which is lodged
in the upper part of the cylinder. Through the centre of a lid, a screw-threaded
rod passes, occupying the axial part of the cylinder; the head of the screw appears
as a button on the lid and is worked with a special key. Within the cylinder the
screw carries a plate P with wing-like extensions preventing it from turning; this
plate presses upon the spring R. When the screw is turned it causes the plate P
to descend or to rise, according to the direction in which it is turned, and in this way
the spring is either tightened or loosened. A nut e is placed on the screw-threaded
rod, a little below the plate P, limiting the play of the latter, so that the spring
cannot be compressed beyond a certain limit. The lower part of the periphery of
the cylinder C is slightly grooved or hollowed inside and bulget outside and forms
an annular chamber pierced with wide openings O, so that as soon as the valve E
rises, the steam can escape freely. Under the valve-seat, are cast-metal arms a
serving as a point of attachment to the rod of the diaphragm piston L; the steam
passes freely between the arms a. A slight play is allowed around the diaphragm
piston L in order that it may not rub against the wall of the bell-shaped valve C.
The top of the diaphmgm piston is hollowed out like a funnel, in oriler that the
condensation water may not gather and falls into the boiler through the passage of
the diaphragm rod . The essential part of this apparatus, is that which closes the
orifice by which the steam makes its escape. In ordinary valves this piece takes the
form of a conical disc; the surface of the disc is subjected to the pressure of
the steam (the steam which should escape when the valve opens). My valve has the
distinguishing characteristic that it is not exposed to any pressure from the steam
escaping at the moment of its opening; this effect is obtained by making the valve grooved
or hollowed, thus giving it the form of a hollow cylinder or rather of a bell; its edges
rest on a seat as in an ordinary valve, and, in this condition it would act as such,
and the steam would exercise its pressure on the inside of the bell. But close to the top of
the bell, a piston is placed forming a diaphragm with a rod attached on the valve
seat. This piston, therefore, is fixed, it masks the top of the bell which is
thus withdrawn from the action of the steam filling the boiler and the lower part of
the bell.
Under these circumstances, the bell-shaped valve tends neither to open nor to
shut by the pressure of the steam. The action is obtained by supplying the valve
with steam taken from right within the boiler by means of a passage pierced in the
rod of the diaphragın piston; this steam takes effect against the top of the fixed
piston and the top of the moveable bell. When the steam pressure equalises the
foad or weight, the bell rises, its edges leave the seat and the steam escapes;
notwithstanding the loss of steam, the top-inside of the bell receives integrally the
whole pressure of the steam which passes through the passage, the diaphragm
piston preventing it from escaping freely at the edges of the bell. It follows that the
valve supports the same pressure, whether it is open or closed.
When the pressure falls in the boiler, the valve falls only as an ordinary one of
conical form. The opening of the valve, by an independent steam supply, allows
the valve to be used with other flnids besides steam, water for example.
The weight, which acts as an equilibrium to the pressure of the steam, is obtained
by the help of a spring enclosed within a casing; its tension may be regulated very
precisely by a fixed-screw device and this tension can be modified, firstly by the
shape of the working head of the screw, and secondly by a nut which limits the
compression of the spring. This limit cannot be exceeded without taking the whole
valve to pieces. The weight, however, may be obtained by means of a lever and
counter-weight, or by a weight acting directly on the valve, as in existing valves.

page_text: The essential object of the invention is the closing-piece of the escape-hole for the
steam and this is not found in any valve used at the present time. The most important
advantages of the valve may be thus summarised: The rise of the valve is
considerable, so that there is a maximum escape of steam as compared with the valve
.passage.
The valve closes simultaneously with the ceasing of the alarm signal. The flap is
well guided and always falls straight back on its seat; there are no friction surfaces
exposed to,the steam.
On the outside, these surfaces are not much reduced and only serve to secure a good
guidance.
The valve operates with steam, compressed air or water indifferently.
The spring can be regulated with great exactness so that the valve will
rise directly the alarm sounds. The latitude of operation can be regulated just as
required.
The operation can only be modified by means of the special key which must not
be accessible to the stoker.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is.:
In a safety valve, the combination of a fixed diaphragm piston with a hollow rod
for direct supply of steam under pressure from the boiler, with a 'bell-shaped
valve held by a device for effecting the equilibrium of the normal pressure,
the valve resting with its lower edge on a valve-seat, provided at the steam escape
opening.
Dated thin th day of Anonat 1007