CLAPET DE FERMETURE AUTOMATIQUE DE ROBINET

AUTOMATIC FLUID FLOW SHUT-OFF DEVICE

Abrégé anglais

ABSTRACT
A gas shut-off device 10 for a gas cylinder, to stop gas flow from
the cylinder if the gas flow becomes excessively high, or the device is
tilted from its normal orientation. The device 10 includes a cylindrical
chamber 21 having a gas inlet 20 and a gas outlet 25, with a ball 22
located within the chamber 21 to close the outlet 25 if the gas flow
becomes excessively high or the device 10 becomes tilted.

Revendications

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The embodiments of the invention in which an exclusive property
or privilege is claimed are defined as follows:
1. A fluid flow shut-off device comprising:
a hollow body having an inlet connection portion to be connected to a
supply of fluid under pressure, and an outlet connection portion to be
connected to an apparatus to receive said fluid, said body providing a
chamber through which the fluid passes from a chamber inlet to a chamber
outlet, said inlet and outlet being positioned so that fluid entering said
chamber enters in a direction having a direction component normal to the
direction of the fluid entering said outlet, with said outlet being
positioned at an upper portion of said chamber when said device is in its
normal operating orientation having said inlet generally horizontally
facing;
a movable valve ball captively located within said chamber to
selectively engage said outlet to prevent fluid flow therethrough, wherein
said ball will engage said outlet when either the fluid flow rate becomes
excessively high through said device or said device is tilted through a
predetermined angle from its normal operating orientation.
2. The fluid flow shut-off device of claim 1, wherein said outlet
is generally downwardly facing and said chamber is of a cylindrical
configuration, with the longitudinal axis thereof vertically oriented
during normal operation.
3. The fluid flow shut-off device of claim 2, wherein said outlet
is provided with a resilient ring against which said ball engages.
4. The fluid flow shut-off device of claim 3, wherein said inlet
connection portion and said outlet connection portion are horizontally
aligned along a common axis, and the longitudinal axis of said chamber
extends generally radially from said common axis.
5. The fluid flow shut-off device of claim 4, further including a
valve actuator extending from said outlet connection portion to said inlet

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connection portion to operate a valve of said supply upon said outlet
connection portion being connected to said apparatus.
6. The fluid flow shut-off device of claim 5, further including a
hollow shaft slided mounted within said body for connection to a pressure
measuring gauge which hollow shaft is movable from a retracted position
clear of said outlet, and a reset position protruding through said outlet
to dislodge said ball.
7. The fluid flow shut-off device of claim 6, wherein said body has
a passage extending along said common axis, which passage receives said
valve actuator, which passage is sealingly divided between a downstream
portion located in said inlet connection portion, and an upstream portion
located in said outlet connection portion.
8. The fluid flow shut-off device of claim 7, wherein said outlet
communicates with said upstream portion, and said downstream portion
communicates with said inlet.
9. The fluid flow shut-off device of claim 2, wherein the ratio of
the ball diameter to the chamber diameter is about .7, and said ball is
formed of steel.
10. The fluid flow shut-off device of claim 2, wherein said ball has
a weight of about 4.3gm and a diameter of about 4.8mm, and said chamber has
a diameter of about 6.6mm.
11. The fluid flow shut-off device of claim 2, wherein said ball has
a weight of about 4.9gm and a diameter of about 5.4mm, and said chamber has
a diameter of about 7.5mm.

Description

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62616-105
Background of the Inven~ion
The present invention relates to fluid flow shut-off
devices and in particular to an emergency, automatic shut-off
device for gas cylinder operation.
Discussion of Prior Art
An automatic fluid flow shut-off device is known in
which a ball moves into engagement with a seat to prevent gas flow
in emergencies. However, it can not be guaranteed that the device
will operate in all circumstances, particularly if the device is
incorrectly oriented relative to the horizontal.
German Specification 2249598 describes a ball valve
which is operated if the gas flow becomes excessive. The valve is
intended to be operated so that the valve is accelerated upwardly
against the force of gravity when the gas flow becomes excessive.
There is no consideration given to providing this valve with a
shut-off function if it becomes incorrectly oriented. Still
further, the various embodiments of this particular device shown
and dlscussed, do not lend themselves to actuation if the device
is merely tilted.
Objects and Summary of the Invention
It is the object of the present invention to overcome or
substantially ameliorate the above disadvantage.
There is disclosed herein a fluid flow shut-off device
comprising:
a hollow body having an inlet connection portion to be
connected to a supply of fluid under pressure, and an outlet
connection portion to be connected to an apparatus to receive said
fluid, said body providing a chamber through which the fluid
passes from a chamber inlet to a chamber outlet, said inlet and
outlet being positioned so that fluid entering said chamber enters
in a direction having a direction component normal to the




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direction of the fluid entering said outlet, w~th said outlet being
positioned at an upper portion of said chamber whell said device is in its
norma7 operating orientation having said inlet generally horizontally
fac~ng;
a movable valve ball captively located within said chamber to
selectively engage said outlet to prevent fluid flow therethrough, wherein
said ball will engage said outlet when either the fluid flow rate becomes
excessively high through said device or said device is tilted through a
predetermined angle from its normal operating orientation.
Brief Description of the Drawing
A preferred form of the present invention will now be described by
way of example with reference to the accompanying drawing, which
schematically depicts in sectioned side elevation a fluid flow shut-off
device.
Description of the Preferred Embodiment
In the accompanying drawing there is schematically depicted a fluid
flow shut-off device 10. The device 10 is connectable to a gas cylinder
(not shown) at the inlet end 11. The connection being any convenient means
such as snap-on, push-on or screw threaded, connection. At its other end,
outlet end 12 is adapted to be connected to a regulator (not shown).
The device 10 has a shaft 13 located in a body 15 adapted to abut a
needle valve of the gas cylinder.
The body 15 has a further passage 16 sealingly engaged by O-rings 17
mounted on the shaft 13. The shaft 13 extends to a leading portion 18.
When connected to the regulator, the leading portion 18 is engaged and the
shaft 13 moved to operate the needle valve of the gas cylinder. The O-rings
17 divide the passage 16 into an upstream and a downstream position.
The passage 15 communicates with a chamber 19 having an inlet chamber
portion 20 and an outlet chamber portion 21. Located in the outlet chamber

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portion 21 is a ball 22. The chamber portion 21 is of a cylindrical
configuration, having its axis normal to the axis of the passage 16.
The chamber portion 21 is provided with an 0-ring 23 against which a
washer 24 bears. The 0-ring 23 and washer 24 provide an outlet passage 25.
The outlet passage 25 is of a smaller cross sectional area than the ball
22, so that upon the ball 22 seating against the 0-ring 23, fluid flow is
prevented.
Fluid leaving the passage 24 passes through the washer 24 via the
passage 25 to an outlet passage 26 to be delivered to the outlet end 12.
It should be appreciated that fluid entering the chamber 21, from the
chamber 20, has a direction of travel at least partly normal to the
direction of travel of fluid entering the passage 25. By providing this
configuration, the device 10, if inadvertently tilted or moved, independent
of the starting orientation, will act to stop gas flow by engagement of the
ball 22 with the 0-ring 23. This will also occur when there is excessively
high gas speeds.
Also mounted in the body 15 is a hollow shaft 27 having a central
passage 28 extending to the passage 25. The passage 28 communicates with a
pressure gauge 29. Still further, the shaft 27 is movable in the direction
of the arrow 39 so that movement of the shaft 27 can move the ball 22 from
engagement with the 0-ring 23 in order to reset the devlce 10.
~ here a steel ball 22 is employed, it has been found that the ratio
of the ball diameter to the diameter of the chamber 21 is.approximately .7.
It has also been found that the ball 22 if provided with a weight of
about 4.3 gm (about 4.8 mm diameter) co-operates with a chamber 21 diameter
of 6.60 mm. As a further alternative, a ball 22 having a weight of 4.871
gm (5.40 mm diameter) co-operates with a chamber 21 diameter of 7.50 mm.



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