AN EXCESS-FLOW SAFETY SHUT-OFF DEVICE

DISPOSITIF DE SECURITE A COUPURE AUTOMATIQUE EN CAS DE DEBIT ELEVE

English Abstract

A fluid flow safely device comprises a body having an inlet
end for connection to a fluid supply and an inlet passageway (8, 48,
103) which leads lo a selective fluid flow sensor chamber (9, 49,
115) having a sealing means (10, 50) which encircles the outlet
orifice (11, 51) of smaller cross section than that of the sensor
chamber, said outlet orifice leading from the sensor chamber into a
pressure chamber (12, 52) within the body leading to an outlet.
Between the inlet end of the sensor chamber and the sealing means
is a tapered section (13, 117), wherein the bore of the sensor
chamber decreases in a diameter as it nears the sealing means. A
sensor chamber shield (120) may encircle the sensor chamber by
forming, defining and separating the internal length of the sensor
chamber passageway from that of the inlet or any other
passageway. A ball (16, 56, 119) in the sensor chamber moves
between the inlet passageway end of the sensor chamber and the
outlet orifice, to form a seal with the sealing means when flow
through the sensor chamber is above a predetermined value.
Within the pressure chamber is a movable piston (20, 60, 131) in
sealing contact with it to increase or decrease the volume of the
pressure chamber. Movement of the movable piston from a rest
position fully towards the sensor chamber will deny a seal to be
made between the ball and the sealing means. The movable piston
may be a primary valve mechanism which forms a seal between the
inlet and outlet passageways. The movable piston may include an
indicator mark visible only when the pressure in the pressure
chamber is above a predetermined value. Embodiments for LP gas
include separate use of sensor chamber or movable piston with or
without primary valve.

French Abstract

L'invention se rapporte à un dispositif de sécurité pour écoulement fluide, qui comprend un logement ayant une extrémité d'entrée destinée à être connectée à une source de fluide ainsi qu'à un conduit d'entrée qui mène à une chambre à capteur d'écoulement fluide sélectif. A l'extrémité de sortie de ladite chambre à capteur est situé un organe d'étanchéité qui entoure l'orifice de sortie, lequel a une section transversale plus petite que la chambre à capteur, ledit orifice de sortie allant de la chambre à capteur jusqu'à une chambre sous pression à l'intérieur du logement. Entre l'extrémité d'entrée de la chambre à capteur et l'organe d'étanchéité est située une section conique, au niveau de laquelle le passage de la chambre à capteur décroît en diamètre au fur et à mesure qu'il se rapproche de l'organe d'étanchéité. Un bouchon mobile, qui est placé dans la chambre à capteur d'écoulement fluide sélectif, peut se déplacer entre la butée d'extrémité du conduit d'entrée de la chambre à capteur et l'orifice de sortie, et ce bouchon mobile a un diamètre plus grand que l'orifice de sortie de la chambre à capteur et il est en mesure de former une obturation en coopérant avec l'organe d'étanchéité. Cette obturation peut se produire lorsque l'écoulement de fluide à travers la chambre à capteur dépasse une valeur prédéterminée. Dans la chambre à capteur se trouve un piston mobile qui est en contact coulissant et étanche avec ladite chambre et dont le mouvement de coulissement à partir d'une position de repos fait augmenter ou diminuer le volume de ladite chambre sous pression. Un conduit allant de la chambre sous pression à une ouverture de sortie peut être raccordé à d'autres mécanismes de transport de fluide. Dans un mode de réalisation, le piston mobile porte un repère qui est visible uniquement lorsque la pression dans la chambre sous pression dépasse une valeur prédéterminée et lorsqu'un mouvement du piston mobile à partir d'une position de repos jusqu'à une position complétement dirigée vers la chambre à capteur empêche toute obturation entre le bouchon mobile et l'organe d'étanchéité. Dans le mode de réalisation préféré, le piston mobile constitue le mécanisme à valve primaire qui forme une obturation entre les conduits d'entrée et de sortie. Autour de la chambre à capteur est disposé un écran qui forme et définit le conduit de la chambre interne et qui sépare la longueur interne de ce conduit de celle du conduit d'entrée ou de tout autre conduit.

Claims

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THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:
1. A fluid flow safety device comprising;
a body, having an inlet for connection to a fluid supply, an
inlet passageway leading to a selective fluid flow sensor chamber, and located
at the outlet end of the said sensor chamber is a sealing means which encircles
an outlet orifice and this outlet orifice is of smaller cross section than that
of the sensor chamber, said outlet orifice leading from the sensor chamber into
a pressure chamber within the body;
a movable piston which makes a sliding and sealing contact
with the pressure chamber, and whose sliding movement from a rest position
increases or decreases the volume of the said pressure chamber;
a passageway extending from the pressure chamber to an
outlet aperture which is connectable to further fluid transport mechanisms;
and a movable plug which is positioned within the selective
fluid flow sensor chamber and can move between the inlet passageway end stop
of the sensor chamber and the outlet orifice, and the movable plug is of greaterdiameter than the sensor chamber outlet orifice and is able to form a seal with
the sealing means.
2. A fluid flow safety device according to claim 1 wherein, the
opposite end of the movable piston to that which is located within the bounds ofthe sliding and sealing contact of the pressure chamber, experiences the effect
of atmospheric pressure.
3. A fluid flow safety device according to claim 1 or claim 2
wherein, the movable piston's central axis is substantially aligned with the
central axis of the sensor chamber.
4. A fluid flow safety device according to any of the preceding
claims wherein, the diameter of the movable plug in relation to the internal
diameter of the sensor chamber allows a predetermined quantity of fluid to flow
to the outlet orifice wherein an increase in the fluid flow above that
predetermined quantity, draws the movable plug into a sealing contact with the
sealing means at the outlet orifice.
5. A fluid flow safety device according to any of the preceding
claims wherein, the sealing means located between the movable plug and the end
of the sensor chamber is an O-ring which encircles the outlet orifice.
6. A fluid flow safety device according to any of the preceding
claims wherein, a plunger is incorporated into the base of the movable piston.
7. A fluid flow safety device according to any of the preceding
claims wherein, the diameter of the plunger is of smaller diameter than the

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diameter of the outlet orifice.
8. A fluid flow safety device according to any of the preceding
claims wherein, when the movable piston is moved fully towards the sensor
chamber, the plunger extends through the outlet orifice sufficiently far to denya seal to occur between the movable plug and the sealing means at the outlet
orifice.
9. A fluid flow safety device according to any of the preceding
claims wherein, the movable piston is biased away from the sensor chamber.
10. A fluid flow safety device according to claim 9 wherein, the
biasing means is a spring.
11. A fluid flow safety device according to claim 9 or claim 10
wherein, if there is no additional force acting upon the movable piston, the
biasing means returns the movable piston to a rest position.
12. A fluid flow safety device according to claim 11 wherein,
when the movable piston travels from its rest position to its extended position
a biasing mechanism is compressed.
13. A fluid flow safety device according to claim 12 wherein,
the biasing mechanism is a spring.
14. A fluid flow safety device according to any of the claims 10
to 13 wherein, the biasing means and the biasing mechanism is the one and the
same spring.
15. A fluid flow safety device according to any of the preceding
claims wherein, a sufficient build up of pressure in the pressure chamber moves
the movable piston from the rest position to its fully extended position.
16. A fluid flow safety device according to any of the preceding
claims wherein, the movable piston includes an extension which is of sufficient
length to protrude proud of the body.
17. A fluid flow safety device according to any of the preceding
claims wherein, an indicator mark is present on the movable piston extension andit is totally visible when the movable piston is in its fully extended position.18. A fluid flow safety device according to any of the preceding
claims wherein, the indicator mark is not visible when the movable piston is
in its rest position
19. A fluid flow safety device according to any of the preceding
claims wherein, an outlet passageway is incorporated into the movable piston.
20. A fluid flow safety device according to claim 19 wherein,
the outlet aperture is incorporated into the extension from the movable piston
which protrudes proud of the body.
21. A fluid flow safety device according to any of the preceding

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claims wherein, the inlet for connection to a fluid supply, the sensor chamber
and the outlet aperture have their central axes aligned to a common datum.
22. A fluid flow safety device according to any of the claims 1
to 20 wherein, the axis of the inlet for connecting to a fluid supply and the
axis of the outlet aperture are aligned to a common datum while the axis of the
sensor chamber is at an angle to that datum.
23. A fluid flow safety device according to any of the claims 1
20 or wherein, the axis of the inlet for the connection to a fluid supply and
the axis of the outlet aperture do not share a common datum.
24. A fluid flow safety device according to any of the preceding
claims wherein, the axis of the inlet passageway and the axis of the inlet for
connection to a fluid supply are not aligned to a common datum.
25. A fluid flow safety device according to any of the preceding
claims wherein, a groove is present in the body in the internal chamber walls,
adjacent to the movable piston, which can accommodate a compression clip ring.
26. A fluid flow safety device according to claim 25 wherein,
the height of the groove in the chamber wall is sufficient to allow the movable
piston to move to a point where the plunger can be inserted through the outlet
orifice to disallow the seal between the sealing means and the movable plug.
27. A fluid flow safety device according to any of the preceding
claims wherein, the groove in the chamber wall and the compression clip ring
are replaced by a circular internal push-on fastener which locates itself onto
the chamber wall.
28. A fluid flow safety device according to any of the claims 14
to 27 wherein, the single spring is located between two spacing ring stops
and is pretensioned by a circlip positioned in a groove on the movable piston.
29. A fluid flow safety device according to claim 27 or claim 28
wherein, the movable piston is located in its rest position due to the
positioning of the single spring and the two spacing ring stops between a step
in the bore of the pressure chamber and a circular internal push-on fastener.
30. A fluid flow safety device according to any of the preceding
claims wherein, an increase of fluid pressure in the pressure chamber above a
predetermined value compresses the spring fully which limits the travel of
the movable piston to its fully extended position.
31. A fluid flow safety device according to any of the preceding
claims wherein, a bypass passageway leads from the inlet passageway and bypassesthe sensor chamber outlet and connects to the outlet passageway.
32. A fluid flow safety device according to claim 31 wherein, a
valve is installed within the bypass passageway.

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33. A fluid flow safety device according to any of the preceding
claims wherein, a filtering material is installed within the inlet passageway.
34. A fluid flow safety device according to any of the preceding
claims wherein, a one way valve is installed in the outlet passageway.
35. A fluid flow safety device according to any of the preceding
claims wherein, part of the bore of the sensor chamber passageway is tapered to
a smaller diameter as it nears the sealing means.
36. A fluid flow safety device according to claim 35 wherein,
the tapered sensor chamber passageway is a separate unit which can provide a
location means for holding the O-ring in place.
37. A fluid flow safety device according to any of the preceding
claims wherein, the sensor chamber can be separated from the body.
38. A fluid flow safety device according to any of the preceding
claims wherein, the sensor chamber and the inlet for connection to a fluid
supply is separate from, and connectable to, the body.
39. A fluid flow safety device comprising;
a body, having an inlet orifice and an inlet passageway
leading to a selective fluid flow sensor chamber, and located at the outlet end
of the said sensor chamber is a sealing means which encircles an outlet orifice
and this outlet orifice is of smaller cross section than that of the sensor
chamber, said outlet orifice leading from the sensor chamber into a pressure
chamber within the body;
a guide for the movable piston is located by the body to
form part of the pressure chamber and has its axis is aligned to the axis of theoutlet orifice;
a movable piston which makes a sliding and sealing contact
with the guide, and whose sliding movement from a rest position increases or
decreases the volume of the pressure chamber;
a passageway extending from the pressure chamber to an
outlet aperture which is connectable to further fluid transport mechanisms;
and a movable plug which is positioned within the selective
fluid flow sensor chamber and can move between the inlet passageway end stop of
the sensor chamber and the outlet orifice, and the movable plug is of greater
diameter than the sensor chamber outlet orifice and is able to form a seal with
the sealing means.
40. A fluid flow safety device according to claim 39 wherein,
an inlet assembly with a fluid passageway and a mating connection forms a fluid
tight seal with the body inlet orifice and further provides a connection to
a fluid supply source.

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41. A fluid flow safety device according to claim 39 or claim 40
wherein, the opposite end of the movable piston to that which is located within
the bounds of the sliding and sealing contact inside the pressure chamber,
experiences the effect of atmospheric pressure.
42. A fluid flow safety device according to any of the claims 39
to 41 wherein, the movable piston's central axis is substantially aligned with
the central axis of the sensor chamber.
43. A fluid flow safety device according to any of the claims 39
to 42 wherein, the diameter of the movable plug in relation to the internal
diameter of the selective fluid flow sensor chamber allows a predetermined
quantity of fluid to flow to the outlet orifice wherein an increase in the fluidflow above that predetermined quantity, draws the movable plug into sealing
contact with the sealing means at the outlet orifice.
44. A fluid flow safety device according to any of the claims 39
or claim 43 wherein, the sealing means located between the movable plug and the
end of the sensor chamber is an O-ring which encircles the outlet orifice.
45. A fluid flow safety device according to any of the claims 39
to 44 wherein, a plunger is incorporated into the base of the movable piston.
46. A fluid flow safety device according to any of the claims 39
to 45 wherein, the diameter of the plunger is of smaller diameter than the
diameter of the outlet orifice.
4?. A fluid flow safety device according to any of the claims 39
to 46 wherein, when the movable piston is moved fully towards the sensor
chamber, the plunger extends through the outlet orifice sufficiently far to denya seal to occur between the movable plug and the sealing means at the outlet
orifice.
48. A fluid flow safety device according to any of the claims 39
to 47 wherein, the movable piston is biased away from the sensor chamber.
49. A fluid flow safety device according to claim 48 wherein,
the biasing means is a spring.
50. A fluid flow safety device according to claim 48 or claim 49
wherein, if there is no additional force acting upon the movable piston, the
biasing means returns the movable piston to a rest position.
51. A fluid flow safety device according to claim 50 wherein,
when the movable piston travels from its rest position to its fully extended
position a biasing mechanism compressed.
52. A fluid flow safety device according to claim 51 wherein,
the biasing mechanism is a spring.
53. A fluid flow safety device according to any of the claims 48

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to 52 wherein, the biasing means and the biasing mechanism is the one and the
same spring.
54. A fluid flow safety device according to any of the claims 39
to 52 wherein, a sufficient build up of pressure in the pressure chamber moves
the movable piston from the rest position to its fully extended position.
55. A fluid flow safety device according to any of the claims 39
to 54 wherein, the movable piston includes an extension which is of sufficient
length to allow that extension to protrude proud of the guide.
56. A fluid flow safety device according to any of the claims 39
to 55 wherein, an indicator mark is present on the movable piston extension
which is totally visible when the movable position is in its fully extended
position.
57. A fluid flow safety device according to any of the claims 39
to 56 wherein, the indicator mark is not visible when the movable piston is
in its rest position.
58. A fluid flow safety device according to any of the claims 52
to 57 wherein, the single spring is located between two spacer rings and is
pretensioned by a circlip positioned in a groove on the movable piston.
59. A fluid flow safety device according to any of the claims 39
to 58 wherein, the movable piston is located in its rest position due to the
positioning of the single spring and the two spacer rings between a step in the
bore of the guide and a vented plug located onto the base of the guide.
60. A fluid flow safety device according to any of the claims 39
to 59 wherein, an additional step is incorporated into the internal bore of the
guide such that an increase of fluid pressure in the pressure chamber above a
predetermined value compresses the spring and the spring spacer adjacent to the
circlip on the movable piston engages with the additional step which limits the
outward travel of the movable piston.
61. A fluid flow safety device according to any of the claims 39
to 60 wherein, the outlet orifice and the sealing means of the sensor chamber
are removable from the body.
62. A fluid flow safety device according to claim 61 wherein,
the removable outlet orifice and the sealing means are held in position by the
vented plug in the base of the guide.
63. A fluid flow safety device according to any of the claims 39
to 62 wherein, the bore of the sensor chamber passageway is tapered to a smallerdiameter as it nears the sealing means.
64. A fluid flow safety device according to claim 63 wherein,
the tapered sensor chamber passageway is a separate unit and can provide a

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location means for holding the 0-ring in place.
65. A fluid flow safety device according to any of the claims 39
to 64 wherein, the sensor chamber can be separated from the body.
66. A fluid flow safety device according to any of the claims 40
to 65 wherein, a filtering material is installed within the inlet assembly fluidpassageway.
67. A fluid flow safety device according to any of the claims 39
to 66 wherein, a one way valve is installed in the outlet passageway.
68. A fluid flow safety device according to any of the claims 39
to 67 wherein, the body has a mating relationship with the inlet assembly such
that the body can be rotated around the axis of the inlet assembly.
69. A fluid flow safety device according to claim 68 wherein,
when the body has been rotated into a fully inverted position, the movable plug
forms a seal with the sealing means of the sensor chamber.
70. A fluid flow safety device according to any of the claims 39
to 69 wherein, a bypass passageway leads from the inlet passageway and bypasses
the sensor chamber outlet.
71. A fluid flow safety device according to any of the claims 39
to 70 wherein, a valve is installed within the bypass passageway.
72. A fluid flow safety device comprising;
an inlet assembly with a fluid passageway for connection
to a fluid supply,
a body having an inlet passageway leading to a selective
fluid flow sensor chamber, and located at the outlet end of the of the said
sensor chamber is a sealing means which encircles an outlet orifice and this
outlet orifice is of smaller cross section than that of the sensor chamber, saidoutlet orifice leading from the sensor chamber to a pressure chamber within the
body;
a movable piston which makes a sliding and sealing contact
within the pressure chamber, and whose sliding movement from a rest position
increases or decreases the volume of the pressure chamber;
a passageway extending from the pressure chamber to an
outlet aperture which is connectable to further fluid transport mechanisms;
a movable plug which is positioned within the selective
fluid flow sensor chamber and is located between the inlet passageway and the
outlet orifice, and the movable plug is of greater diameter than the sensor
chamber outlet orifice;
and a separate shut-off mechanism to provide an independent
control for terminating the fluid flow.

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73. A fluid flow safety device according to claim 72 wherein,
the diameter of the movable plug in relation to the internal diameter of the
sensor chamber allows a predetermined quantity of fluid to flow to the outlet
orifice wherein an increase in the fluid flow above that predetermined quantity,draws the movable plug into a sealing contact with the sealing means at the
outlet orifice.
74. A fluid flow safety device according to claim 72 or claim 73
wherein, the sealing means located between the movable plug and the end of the
sensor chamber is an 0-ring which encircles the outlet orifice.
75. A fluid flow safety device according to any of the claims 72
to 74 wherein, the opposite end of the movable piston to that which is located
within the bounds of the sliding and sealing contact of the pressure chamber,
experiences the effect of atmospheric pressure.
76. A fluid flow safety device according to any of the claims 72
to 75 wherein, the movable piston's central axis is substantially aligned with
the central axis of the sensor chamber.
77. A fluid flow safety device according to any of the claims 72
to 76 wherein, the separate shut-off mechanism can also initiate the fluid flow.78. A fluid flow safety device according to any of the claims 72
to 77 wherein, the separate shut-off mechanism is located upstream of the sensorchamber.
79, A fluid flow safety device according to any of the claims 72
to 78 wherein, the separate shut-off mechanism is biased towards the closed
position.
80. A fluid flow safety device according to any of the claims 72
to 79 wherein, the separate shut-off mechanism which is biased towards the
closed position is held in the open state by a triggering system.
81. A fluid flow safety device according to any of the claims 72
to 80 wherein, the triggering system is responsive to vibration movement.
82. A fluid flow safety device according to any of the claims 72
to 80 wherein, the triggering system is responsive to heat.
83. A fluid flow safety device according to any of the claims 72
to 80 wherein, the triggering system is responsive to an electrical impulse.
84. A fluid flow safety device according to any of the claims 72
to 80 wherein, the triggering system incorporates a sensing chamber which will
activate the trigger in responsive to a change in the fluid pressure.
85. A fluid flow safety device according to any of the claims 72
to 84 wherein, the separate shut-off mechanism causes the movable plug in the
sensor chamber to form a seal with the sealing means which encircles the outlet

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orifice.
86. A fluid flow safety device according to any of the claims 72
to 77 wherein, the separate shut-off mechanism is located downstream of the
sensor chamber outlet orifice.
87. A fluid flow safety device according to claim 86 wherein,
the separate shut-off mechanism valve seat encircles the outlet side passagewayof the sensor chamber outlet orifice.
88. A fluid flow safety device according to claim 86 or claim 87
wherein, the separate shut-off mechanism valve plug is located such that it
forms a fluid seal with the separate shut-off mechanism valve seat.
89. A fluid flow safety device according to claim 88 wherein,
the separate shut-off mechanism valve plug is incorporated onto the base of the
movable piston.
90. A fluid flow safety device according to any of the claims 86
to 89 wherein, the movable piston is propelled into its closed position by
the action of a spindle mechanism.
91. A fluid flow safety device according to any of the claims 86
to 90 wherein, the axes of the separate shut-off mechanism valve plug, spindle,
valve seat and sensor chamber share a common datum.
92. A fluid flow safety device according to any of the claims 86
to 91 wherein, the movable piston is biased from its rest position by a
sufficient build up of pressure in the pressure chamber.
93. A fluid flow safety device according the claim 92 wherein,
when the spindle has been retracted to its open position and there is a
sufficient build up of pressure in the pressure chamber, the movable piston
moves the separate shut-off mechanism valve plug to an open state.
94. A fluid flow safety device according to any of the claims 72
to 93 wherein, the separate shut-off mechanism valve plug includes a protrusionpin which extends through an oversized orifice from the base of the valve plug.
95. A fluid flow safety device according to any of the claims 72
to 94 wherein, the protrusion pin extending from the base of the valve plug is
of smaller diameter than that of the outlet orifice.
96. A fluid flow safety device according to any of the claims 72
to 95 wherein, as the separate shut-off mechanism valve plug approaches its
closed position, the protrusion pin denies a seal to occur between the movable
plug and the sealing means.
97. A fluid flow safety device according to any of the claims 90
to 93 wherein, within the movable piston is a cylindrical chamber whose axis is
aligned with that of the movable piston.

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98. A fluid flow safety device according to claim 97 wherein,
one end of the reset plunger pin makes a sliding, sealing contact within the
cylindrical chamber while the other end is located within an oversized orifice
in the centre of the separate shut-off mechanism valve plug.
99. A fluid flow safety device according to claim 97 or claim 98
wherein, the reset plunger pin within the cylindrical chamber is biased to a
retracted position.
100. A fluid flow safety device according to any of the claims 97
to 99 wherein, the end of the reset plunger pin which makes a sliding and
sealing contact within the cylindrical chamber experiences the effect of
atmospheric pressure.
101. A fluid flow safety device according to claim 99 or claim
100 wherein, the biasing means for the reset plunger pin is a sufficient build
up of pressure in the cylindrical chamber which moves the reset plunger to
a retracted state.
102. A fluid flow safety device according to any of the claims 97
to 101 wherein, the spindle has a central guide hole present which extends
longitudinally through its central axis.
103. A fluid flow safety device according to any of the claims 90
to 102 wherein, a reset shaft is located within the spindle's guide hole.
104. A fluid flow safety device according to any of the claims 90
to 103 wherein, the reset shaft is biased towards a rest position.
105. A fluid flow safety device according to claim 104 wherein,
the biasing means is a spring.
106. A fluid flow safety device according to any of the claims 97
to 105 wherein, when the reset shaft is moved to its reset position it engages
with the reset plunger pin and extends it through the separate shut-off
mechanism valve seat to its reset position.
107. A fluid flow safety device according to claim 106 wherein,
as the separate shut-off mechanism valve plug approaches its closed position,
the reset plunger pin denies a seal to occur between the movable plug and the
sealing means.
108. A fluid flow safety device according to any of the claims
103 to 107 wherein, the reset shaft has a second biasing means which locates
it into a rest position.
109. A fluid flow safety device according to claim 108 wherein,
the second biasing means is a spring.
110. A fluid flow safety device according to any of the claims
103 to 109 wherein, the reset shaft includes an extension which protrudes past

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the outside end of the spindle.
111. A fluid flow safety device according to any of the claims
103 to 110 wherein, an indicator mark is present on the reset shaft extension
which is only visible when the reset shaft is in its fully extended position.
112. A fluid flow safety device according to claim 110 or claim
111 wherein, when there is sufficient pressure built up around the oversized
orifice of the plug, valve the reset plunger pin moves to its fully retracted
state and compresses the second biasing means which causes the indicator mark
on the reset shaft extension to become visible.
113. A fluid flow safety device according to any of the claims 72
to 112 wherein, a bypass passageway leads from the inlet passageway and bypassesthe sensor chamber outlet and connects to the outlet passageway.
114. A fluid flow safety device according to claim 113 wherein, a
valve is installed within the bypass passageway.
115. A fluid flow safety device according to claim 114 wherein,
the valve is a solenoid valve.
116. A fluid flow safety device according to any of the claims 72
to 115 wherein, a filtering material is installed within the inlet passageway.
117. A fluid flow safety device according to any of the claims 72
to 116 wherein, a one way valve is installed in the outlet passageway.
118. A fluid flow safety device according to any of the claims 72
to 117 wherein, the bore of the sensor chamber passageway is tapered to a
smaller diameter as it nears the sealing means.
119. A fluid flow safety device according to claim 118 wherein,
the tapered sensor chamber passageway is a separate unit which can provide a
location means for holding the O-ring in place.
120. A fluid flow safety device according to any of the preceding
claims wherein, the sensor chamber and the sealing means can be separated from
the body.
121. A fluid flow safety device comprising;
a body having an inlet end for connection to a fluid supply
and an outlet end for connecting to further fluid transport mechanisms, an inletpassageway leading to a valve orifice passageway which leads to a primary valve
seat and primary valve pressure chamber which connects via the outlet passagewayto the outlet end;
a primary valve mechanism is located within the primary
valve pressure chamber such that it can form a fluid tight seal between the
inlet and the outlet passageways by engaging with the primary valve seat;
a selective fluid flow sensor chamber positioned between the

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inlet end and the primary valve seat and located at the outlet end of the said
sensor chamber is a sealing means which encircles an outlet orifice and this
outlet orifice is of smaller cross section than that of the sensor chamber
said outlet orifice leading from the sensor chamber to the valve orifice;
a sensor chamber shield which encircles the sensor chamber
by forming, defining and separating the internal length of the sensor chamber
passageway from that of the inlet or any other passageway;
a movable plug which is positioned within the fluid flow
sensor chamber and can move between the inlet passageway end of the sensorchamber and the outlet orifice, and the movable plug is of greater diameter thanthe sensor chamber outlet orifice and is able to form a seal with the sealing
means.
122. A fluid flow safety device according to claim 121 wherein,
the movable plug in its open position is located in the centre of the inletend of the sensor chamber.
123. A fluid flow safety device according to claim 121 or claim
122 wherein, during the refilling process where the fluid flow travels in the
reverse direction to normal, all of the fluid is allowed to flow through the
full length of the sensor chamber, thus cleaning the full length of the sensorchamber and then to flow past the movable plug which is located firmly into
a rest position which prevents it from moving or vibrating.
124. A fluid flow safety device according to any of the claims
121 to 123 wherein, the body and the sensor chamber shield are of unity
construction and are manufactured from the one piece of material.
125. A fluid flow safety device according to any of the claims
121 to 124 wherein, three or more detents or fingers supported by the sensor
chamber shield provide the open position for the movable plug.
126. A fluid flow safety device according to any of the claims
121 to 125 wherein, a safety valve passageway extends from the inlet passagewayto a safety valve mechanism which has been designed to vent to the atmosphere
that fluid from the safety valve passageway should the pressure in that
passageway raise above a predetermined value.
127. A fluid flow safety device according to any of the claims
121 to 126 wherein, the safety valve passageway encircles the sensor chambershield.
128. A fluid flow safety device according to any of the claims
121 to 127 wherein, the diameter of the movable plug in relation to the internaldiameter of the sensor chamber allows a predetermined quantity of fluid to
flow to the outlet orifice wherein an increase in the fluid flow above that

- 26 -
predetermined quantity, draws the movable plug into a sealing contact with
the sealing means at the outlet orifice.
129. A fluid flow safety device according to any of the claims
121 to 128 wherein, the responsiveness of the closing ability of the movableplug remains unaltered regardless of any discharge from the safety valve.
130. A fluid flow safety device according to any of the claims
121 to 129 wherein, the sealing means located between the movable plug and
the end of the sensor chamber is an O-ring which encircles the outlet orifice.
131. A fluid flow safety device according to any of the claims
121 to 130 wherein, part of the bore of the sensor chamber passageway is taperedto a smaller diameter as it nears the sealing means.
132. A fluid flow safety device according to any of the claims
121 to 131 wherein, the tapered sensor chamber passageway is a separate unit
which can provide a location means for holding the O-ring in place.
133. A fluid flow safety device according to any of the claims
121 to 132 wherein, the opposite end of the primary valve to that which is
located within the bounds of the sliding and sealing contact of the primary
valve pressure chamber, experiences the effect of atmospheric pressure.
134. A fluid flow safety device according to any of the claims
121 to 133 wherein, the primary valve's central axis is substantially aligned
with the central axis of the sensor chamber.
135. A fluid flow safety device according to any of the claims
121 to 134 wherein, a separate shut-off mechanism is located upstream of the
sensor chamber.
136. A fluid flow safety device according to any of the claims
121 to 135 wherein, the separate shut-off mechanism can also initiate the fluid
flow.
137. A fluid flow safety device according to any of the claims
121 to 136 wherein, the separate shut-off mechanism is biased towards the closedposition.
138. A fluid flow safety device according to any of the claims
121 to 137 wherein, the separate shut-off mechanism which is biased towards the
closed position is held in the open state by a triggering system.
139. A fluid flow safety device according to any of the claims
121 to 138 wherein, the triggering system is responsive to vibration movement.
140. A fluid flow safety device according to any of the claims
121 to 139 wherein, the triggering system is responsive to an external signal.
141. A fluid flow safety device according to any of the claims
121 to 140 wherein, the triggering system incorporates a sensing chamber which

- 27 -
will activate the trigger in responsive to a change in the fluid pressure.
142. A fluid flow safety device according to any of the claims
121 to 141 wherein, the separate shut-off mechanism causes the movable plug in
the sensor chamber to form a seal with the sealing means which encircles theoutlet orifice.
143. A fluid flow safety device according to any of the claims
121 to 142 wherein, the primary valve seat encircles the outlet passageway side
of the sensor chamber outlet orifice.
144. A fluid flow safety device according to claim 143 wherein,
the primary valve is propelled into its closed position by the action of a
spindle mechanism.
145. A fluid flow safety device according to any of the claims
121 to 144 wherein, the axes of the primary valve, spindle, primary valve seat
and sensor chamber share a common datum.
146. A fluid flow safety device according to any of the claims
121 to 145 wherein, when the spindle has been retracted to an open position,
it moves the primary valve to an open state.
147. A fluid flow safety device according to any of the claims
121 to 145 wherein, when the spindle has been retracted to its open positionand there is a sufficient build up of pressure in the pressure chamber, the
pressure moves the primary valve to an open state.
148. A fluid flow safety device according to any of the claims
121 to 147 wherein, the primary valve includes a protrusion pin which extends
from the base of the primary valve.
149. A fluid flow safety device according to any of the claims
121 to 148 wherein, the protrusion pin extending from the base of the primary
valve is of smaller diameter than that of the outlet orifice.
150. A fluid flow safety device according to any of the claims
121 to 149 wherein, as the primary valve approaches its closed position, theprotrusion pin denies a seal to occur between the movable plug and the sealing
means.
151. A fluid flow safety device according to any of the claims
121 to 150 wherein, within the primary valve is a cylindrical chamber whose
axis is aligned with that of the movable piston.
152. A fluid flow safety device according to claim 151 wherein,
within the cylindrical chamber is a reset pin, one end of which makes a sealing
and sliding contact with the cylindrical chamber while the other end is located
an oversized orifice in the centre of the primary valve.
153. A fluid flow safety device according to claim 151 or claim

- 28 -
152 wherein, when the reset pin has been moved to the bottom of the cylindrical
chamber, the other end of the reset pin protrudes proud of the base of the
primary valve.
154. A fluid flow safety device according to any od the claims
151 to 153 wherein, as the primary valve approaches or is at its closed
position, the reset pin can be moved to the botom of the cylindrical chamber
which allows the other end of the reset pin to deny a seal to occur between
the movable plug and the sealing means.
155. A fluid flow safety device according to any of the claims
121 to 154 wherein, the selective fluid flow sensor chamber and/or the sensor
chamber shield are removable from the body.
156. A fluid flow safety device according to any of the claims
121 to 155 wherein, when the pressure in the pressure chamber is above a
predetermined valve, an external indicator registers the pressure increase.
157. A fluid flow safety device according to any of the previous
claims wherein, the movable plug is a metal ball.
158. A fluid flow safety device according to any of the previous
claims wherein, the movable ball is biased towards the open position.
159. A fluid flow safety device according to claim 158 wherein,
the biasing means is a magnetic force.
160. A fluid flow safety device according to any of the previous
claims wherein, when the movable piston is in the rest position, the free flow
of fluid from the inlet to the outlet passageway is severely restricted.
161. A fluid flow safety device according to any of the previous
claims wherein, the internal passageways include a flashback arrester.
162. A fluid flow safety device according to any of the claims 1
to 38 and claims 121 to 161 wherein, the body is mounted vertically.
163. A fluid flow safety device according to any of the claims 39
to 120 and claim 161 wherein, the body is mounted in a horizontal orientation.
164. A fluid flow safety shut-off mechanism comprising;
an attaching guide housing which is connectable with a fluid
flow safety device body, said attaching guide housing containing a central guidehole and a mating connection for a spindle mechanism;
a movable piston which makes a sealing and sliding contact
within the central guide hole in the attaching guide housing, said movable
piston containing a cylindrical chamber and a valve plug;
a reset plunger pin, one end of which makes a sliding,
sealing contact within the cylindrical chamber while the other end is located
within an oversized orifice in the centre of the valve plug;

- 29 -
a spindle mechanism which makes a mating connection with
the attaching guide housing and which, when rotated towards its closed position,urges the movable piston from the attaching guide housing and the said spindle
contains a central guide hole which extends longitudinally through its centralaxis;
a handle which combines with the spindle to transmit the
rotational movement to the spindle.
165. A fluid flow safety shut-off mechanism according to claim
164 wherein, a reset shaft is located within the spindle's guide hole.
166. A fluid flow safety shut-off mechanism according to claim
164 and claim 165 wherein, the reset shaft is biased towards a rest position.
167. A fluid flow safety shut-off mechanism according to any of
the claims 164 to 166 wherein, the biasing means is a spring.
168. A fluid flow safety shut-off mechanism according to any of
the claims 164 to 167 wherein, when the reset shaft is moved to its reset
position, it engages with the reset plunger pin and extends it through the valveplug to its reset position.
169. A fluid flow safety shut-off mechanism according to claim
166 wherein, when it is installed into a matching fluid flow safety device aspreviously described, and as the valve plug approaches or is at its closed
position and the reset shaft is depressed, the reset plunger pin denies a seal
to occur between the movable plug and the sealing means.
170. A fluid flow safety shut-off mechanism according to any of
the claims 164 to 169 wherein, the reset shaft has a second biasing means whichlocates it into a rest position.
171. A fluid flow safety shut-off mechanism according to claim
170 wherein, the biasing means is a spring.
172. A fluid flow safety shut-off mechanism according to any of
the claims 164 to 171 wherein, the reset shaft includes an extension whichprotrudes past the outside end of the spindle.
173. A fluid flow safety shut-off mechanism according to any of
the claims 164 to 172 wherein, an indicator mark is present on the reset shaft
extension which is only visible when the reset shaft is in its fully extended
position.
174. A fluid flow safety shut-off mechanism according to claim
172 or claim 173 wherein, when there is a sufficient build up of pressure
around the oversized orifice of the valve plug, the reset plunger pin moves to
its fully retracted state and compresses the second biasing means which causes
the indicator mark on the reset shaft extension to become visible.

- 30 -
175. A fluid flow safety shut-off mechanism according to any of
the claims 121 to 174 wherein, an inter-lock is included on the primary valve
mechanism which requires a specific form of manual manipulation to establish
a fluid flow after the primary valve has been turned off thus providing "child
safe" protection.
176. A fluid flow safety device, substantially as hereinbefore
described with reference to the accompanying drawings.

Description

W 095l05554 2 1 6 9 1 9 2 PCT/AU94/00453
AN EXCESS-FLOW SAFETY SHUT-OFF DEVICE
This invention relates to the provision of a user friendly,
inexpensive and simplified excess-flow safety shut-off device for the control ofhazardous, expensive or precious fluids. While this invention was originally
developed to provide additional protection for LP gas users, it has wider
applications than that of just gas cylinder operations. For simplicity however,
it will be described with reference to LP gas applications in this text. This
safety device particularly addresses the requirement to contain flammable gases
in the cylinder when a variety of potentially hazardous situations occur. For
particular applications, it also helps ensure the correct orientation of the gascylinder so that only fuel in its gaseous state can proceed from the cylinder
and through the device.
LP gas is an efficient, effective and economical fuel source
which, when treated correctly, is completely safe. However time, wear and tear,
customer misuse and equipment failures can produce a variety of unsafeoperational conditions which this invention specifically seeks to address.
BACKGROUND ART
Previous inventions relating to safety shut-off devices for
LP, butane, coal or natural gas, reference the different methods of housing,
locating or resetting the various shut-off valve me~h~ni~ ~ which terminate the
fluid flow when certain operational conditions are encountered. Many of the
previous inventions, which range from the over simplified to the complex, only
provide an adequate level of protection in a very limited number of operational
states, are not consistent regarding their shut-off flow rates and often containadditional components which ~are either not required, which require regular
servicing, which can be confusing, which do not enhance the safety functioning
of the shut-off device or whose presence only adds to the cost of manufacture
which, in turn, increases the retail price of the unit.
Previous devices which include gas pressure gauges often
cause operators to believe that they now have an indication of the gas contents
of the cylinder when, in fact, all they have is an indication of the actual gas
pressure of the supply line at that moment. When LP gas converts from its liquidto its gaseous state, it expands some two hundred and seventy times in volume.
~ 35 When contained within a sealed cylinder, Boyle's Law can be used to help show
the ratio of gas to fluid and the pressure at various temperatures. Therefore, avery small quantity of fluid LP gas within the cylinder can register a pressure
of around one hundred pounds per square inch, which is within the bounds of the
normal supply pressure and wnich is the reading that a full cylinder will
Sm3SlllUl~ SB ~R~e 26)

W095,~5554 2 1 6 9 1 9 2 2 - PCTIAU94/00453
register, even though the cylinder is almost empty. When this normal pressure
is observed, some operators therefore expect that the cylinder contains an
adequate supply of gas for their i ed;~te needs. When this is found to be
not the case, the safety device is often considered to be somehow faulty and
is then removed from the system, thus eliminating whatever level of safety
shut-off protection which was being provided by that device.
Some of the previous devices do not shut-off if the gas
cylinder falls onto its side or, if a less than half full cylinder is being
operated while lying on its side. The orientation of the gas cylinder should
effect the shut-off device as, in some instances, this is the only method of
detecting that an unsafe condition exists and prevents it from then becoming
life threatening. For example, a mantle lantern mounted onto a small portable
gas cylinder in a camping type situation should not remain operational when
lying on its side.
Another problem which inflicts many of the previous
inventions is that they are inconsistent with regard to their -~i flow
rates. These flow rates should be at their ~i when the cylinder is in its
correct orientation and must then decrease as the cylinder deviates from that
orientation regardless through which axes the deviation is occurring. Many of
the previous inventions are sensitive to one style of deviation and tests have
shown that, instead of registering reduced fluid flows when placed in these
positions, they actually register substantially increased flows.
Many of the disadvantages of the previous invention include
their methods of construction. Those that contain user serviceable components,
adjustment ~ch~ni! or those which can be dissembled, all lend themselves to
the effects of incorrect reassembly or tampering. This can seriously effect
their efficiency of operation.
DISCLOSURE OF THE lNV~NllON
It is therefore an object of the present invention to
overcome the abovementioned problems in a reliable and inexpensive manner.
According to one form of the present invention there is provided a fluid flow
safety device comprising; a body, having an inlet for connection to a fluid
supply, an inlet passageway leading to a selective fluid flow sensor chamber,
and located at the outlet end of the said sensor chamber is a sealing means
which encircles an outlet orifice and this outlet orifice is of smaller cross
section than that of the sensor chamber, said outlet orifice leading from the
sensor chamber into a pressure chamber within the body; a movable piston which
makes a sliding and sealing contact with the pressure chamber, and whose sliding
~U~-lllUl~ SHE3Er ~e ~

W 095/05554 3 ~ 2 1 6 9 1 9 2 PCT/AU94/00453
movement from a rest position increases or decreases the volume of the said
pressure chamber and a plunger is incorporated into the base of the movable
piston and an indicator mark on the movable piston is visible when the pressure
in the pressure chamber is above a predetermined valve; a passageway extending
from the pressure chamber to an outlet aperture which is connectable to further
fluid transport -ch~ni ~; and a movable plug which is positioned within the
` selective fluid flow sensor chamber and can move between the inlet passageway
end stop of the sensor chamber and the outlet orifice, and the movable plug
is of greater diameter than the sensor chamber outlet orifice and is able to
form a seal with the sealing means and the diameter of the movable plug in
relation to the internal diameter of the sensor chamber allows a predetermined
quantity of fluid to flow to the outlet orifice wherein an increase in the
fluid flow above that predetermined quantity, draws the movable plug into a
sealing contact with the sealing means at the outlet orifice.
15In another form of the present invention there is provided a
fluid flow safety device comprising; a body, with an inlet assembly cont~ining
a fluid passageway which provides a mating connection to form a fluid tight
seal between the body inlet orifice and is connectable to a fluid supply source
and, has an inlet passageway leading to a selective fluid flow sensor chamber,
and located at the outlet end of the said sensor chamber is a sealing means
which encircles an outlet orifice and this outlet orifice is of smaller cross
section than that of the sensor chamber, said outlet orifice leading from the
sensor chamber into a pressure chamber within the body; a guide for the movable
piston is located onto the body to form part of the pressure chamber and has
its axis is aligned to the axis of the outlet orifice; a movable piston which
makes a sliding and sealing contact with the guide, and whose sliding movement
increases or decreases the volume of the pressure chamber and a plunger is
incorporated into the base of the movable piston and an indicator mark on the
movable piston is visible when the pressure in the pressure chamber is above
a predetermined valve; a passageway extending from the pressure chamber to
an outlet aperture which is connectable to further fluid transport mechanisms;
and a movable plug which is positioned within the selective fluid flow sensor
chamber and can move between the inlet passageway end stop of the sensor chamberand the outlet orifice, and the movable plug is of greater diameter than the
sensor chamber outlet orifice and is able to form a seal with the sealing means
and the diameter of the movable plug in relation to the internal diameter of
the sensor chamber allows a predetermined quantity of fluid to flow to the
outlet orifice wherein an increase in the fluid flow above that predetermined
quantity, draws the movable plug into sealing contact with the sealing means at
~U~-lllUl~ SH33Er ~R~c 26)

- 2169192 4
W095/05554 PCT/A~5~/~C~
the outlet orifice.
In another form of the present invention there is a fluid
flow safety device comprising; an inlet assembly with a fluid passageway for
connection to a fluid supply, a body having an inlet passageway leading to
a selective fluid flow sensor chamber, and located at the outlet end of the
of the said sensor chamber is a sealing means which encircles an outlet orifice
and this outlet orifice is of smaller cross section than that of the sensor
chamber, said outlet orifice leading from the sensor chamber to a pressure
chamber within the body; a movable piston which makes a sliding and sealing
contact within the pressure chamber, and whose central axis is aligned with
the central axis of the sensor chamber and the opposite end of the movable
piston to that which is located within the bounds of the sliding and sealing
contact of the pressure chamber, experiences the effect of atmospheric pressure;a passageway extending from the pressure chamber to an outlet aperture which
is connectable to further fluid transport ~-hAni! ~; a movable plug which
is positioned within the selective fluid flow sensor chamber and is located
between the inlet passageway and the outlet orifice, and the movable plug is
of greater diameter than the sensor chamber outlet orifice and the diameter
of the movable plug in relation to the internal diameter of the sensor chamber
allows a predetermined quantity of fluid to flow to the outlet orifice wherein
an increase in the fluid flow above that predetermined quantity, draws the
movable plug into a sealing contact with the sealing means at the outlet
orifice; and a separate shut-off ~~hAni! to provide an independent control
for terminating or initiating the fluid flow wherein part of the separate
shut-off -ch~ni can be biased towards the closed position and can be held
in the open state by a triggering system.
In another form of the present invention there is provided
a fluid flow safety device comprising; a body having an inlet end for connectionto a fluid supply and an outlet end for connection to further fluid transport
~chAni~ ~, an inlet passageway leading to a valve orifice passageway which
leads to a primary valve seat and primary valve pressure chamber which connects
via the outlet passageway to the outlet end; a primary valve l?chAni is
located within the primary valve pressure chamber such that it can form a fluid
tight seal between the inlet and the outlet passageways by engaging with the
primary valve seat; a selective fluid flow sensor chamber and located at the
outlet end of the said sensor chamber is a sealing means which encircles an
outlet orifice and this outlet orifice is of smaller cross section than that
of the sensor chamber said outlet orifice leading from the sensor chamber to
the valve orifice; a sensor chamber shield which encircles the sensor chamber
~U~lllUl~ SED3Er ~e 26~

W095/05554 - 5 - 2 1 6 ~ 1 9 2 rcTlAu94loo453
by forming, defining and separating the internal length of the sensor chamber
passageway from that of the inlet or any other passageway; a movable plug which
is positioned within the fluid flow sensor chamber and can move between the
inlet passageway end of the sensor chamber and the outlet orifice and is able 5 to form a seal with the sealing means; a safety valve passageway extends from
the inlet passageway to a safety valve ~hAni- which has been designed to
vent to the atmosphere that fluid from the safety valve passageway should the
pressure in that passageway rise above a predetermined valve.
In another form of the present invention there is a fluid
flow safety shut-off mechAni ! comprising; an attAching guide housing which is
connectable with a fluid flow safety device body, said attAching guide housing
contAining a central guide hole and a mating connection for a spindle -^hAni!
a movable piston which makes a sealing and sliding contact within the central
guide hole in the attaching guide housing, said movable piston containing a
cylindrical chamber and a valve plug; a reset plunger pin, one end of which
makes a sliding, sealing contact within the cylindrical chamber while the other
end is located within an oversized orifice in the centre of the valve plug; a
spindle echAnism which makes a mating connection with the attaching guide
housing and which, when rotated towards its closed position, urges the movable
piston from the attaching guide housing and the said spindle contains a central
guide hole which extends longitudinally through its central axis; a handle
which combines with the spindle to transmit the rotational movement to the
spindle; a reset shaft which, when moved to its reset position, engages with thereset plunger pin and extends it through the valve plug to its reset position;
and an indicator mark is present on the reset shaft extension which is only
visible when the reset shaft is in its fully extended position.
BRIEF DESCRIPTIONS OF THE DRAWINGS
As there are several different presentations for this
invention they will now be described, by way of example only, with reference to
the accompanying drawings wherein:
figure 1 shows the operational and pressurized condition of
one version of the vertical presentation of the fluid flow safety device while,
figure 2 shows the shut-off condition of the same vertical
version while,
figure 3 shows the reset condition of the same vertical
version while,
figure 4 shows the operational and pressurized condition of
one version of the horizontal presentation of the fluid flow safety device
~U~ lUl~ S~ l ~ C ~

W 095/05554 2 1 6 9 1 9 2 6 - PCT/AU94/00453
while,
figure 5 shows the shut-off condition of the activation
components of the same horizontal version while,
figure 6 shows the reset condition of the activation
components of the same horizontal version while,
figure 7 shows the operational and pressurized condition
of the version of the fluid flow safety device for mounting directly into the
main outlet of the gas cylinder while,
figure 8 shows the rest position of the fluid flow safety
shut-off l--h~ni ! while,
figure 9 shows the reset position of the fluid flow safety
shut-off ?chAni! while,
figure 10 shows the pressurized position of the fluid
flow safety shut-off ?ch~n;! .
In the drawings designated as figures 1, 2 and 3 there is
shown a vertical version of a fluid flow safety device 1 which is connectable
to a gas cylinder (not shown) at the inlet end 2 of the body 3. In the version
shown in these figures the inlet assembly 4 is separate from, and connectable
to the body 3. As this version is designed to have a metal inlet assembly and
a plastic body, the 0-ring 5 provides a fluid tight seal between the two
components. The upper periphery 6 of the inlet assembly is crimped into the
groove 7 located on the lower portion of the body. This design seeks to
substantially reduce the cost of manufacture while still meeting those
regulatory requirements which demand a metal body for the cont~in -nt offlammable gases. In this design, should the unit become engulfed in flames
and the plastic components melt and loose the ability to contain the fluid,
the excess flow will be contained within the metal inlet assembly as the movableplug forms a seal with the sealing means. However, it is envisaged that the
inlet assembly and the body can be manufactured from the same material and
this will in no way alter the intent of this invention.
Contained within the inlet assembly is an inlet passageway 8
which leads to a selective fluid flow sensor chamber 9 and a sealing means
10 which encircles the outlet orifice 11 of the sensor chamber which leads
to a pressure chamber 12 within the body. In these three drawings the sealing
means is shown as an 0-ring which is held in place with a removable tapered
sensor chamber passageway 13. A inlet passageway end stop 14 is firmly inserted
into the end of the inlet passageway and, as it is highly resistant to being
removed, renders the sensor chamber tamper proof. The inlet passageway end
stop also locates the removable sensor chamber passageway in its correct
~Uk~lllUl~ S~:k~ ~ ~

W095/05554 ~ 7 ~ 2 1 6 9 1 9 2 PCT/AU94/00453
position. It should be noted that the sealing means can also be a radius which
matches the movable plug and can be machined into the end of the sensor chamber
and the cylindrical walls of the sensor chamber can then be formed to resemble
the profile of the internal passageway as shown by the removable tapered sensor
chamber passageway. The inlet passageway end stop can have a tapered outlet
15 which combines with the movable plug 16 to provide a one way valve. Also,
the inlet passageway end stop can contain a filtering material within its
passageway to help ensure that foreign material is excluded from the sensor
chamber. The positioning of the movable plug within the sensor chamber herein
defined by a larger diameter 17, a tapered section 18 and a smaller diameter
19 enhances the effects of Bernoulli's theorem on the movable plug in that
as the movable plug is drawn towards the outlet orifice by the flow of the
fluid, as the movable plug approaches the outlet orifice the pressure increases
until the seal with the sealing means is achieved. Also, the tapered section
allows for a much lower flow rate to move the movable plug to the sealing means
when the unit is in a horizontal Al ign -nt. Thus, if the unit falls onto its
side, it is very responsive to a quick shut-off.
Within the pressure chamber of the body is movable piston 20
which has two circlip grooves 21 and 22, a passageway 23 and an extension 24
at the outlet end for connection to further fluid transport mechAni! ~. Betweenthe two circlips 25 and 26 are two spacer rings 27 and 28 and between them
are two 0-rings 29 and 30 and a shim 31. While two 0-rings are not essential,
many of the regulatory authorities require a double seal between a pressure
chamber and atmosphere. Between the circlip 26 and the further fluid transport
--hAni ~m iS a spacing ring stop 32, a spring 33 and an inverted spacing ring
stop 34. Within the step in the chamber walls 35 of the body is a circular
internal push-on fastener 36 which, when in place, renders the top end of the
unit virtually tamper proof. It should be noted that the inverted spacing ring
stop and the internal push-on fastener could be replaced by a groove in the
pressure chamber walls and a compression clip ring. There is a groove 37 in
the extension of the movable piston which contains a indicator mark 38 which
could be a green neoprene 0-ring. Mounted onto the base of the movable piston
is a plunger 39 which has a passageway 40 which allows fluids to flow between
the pressure chamber and the passageway 23. At the narrow passage 41 can be
installed a one way valve should the need arise.
In figure 1, the fluid flow safety device is shown in the
condition that it will be in when it is passing pressurized fluid at a rate
below the -~i predetermined flow rate for that unit. The movable plug is
near the base of the sensor chamber and the pressure in the pressure chamber
~U~SlllUl~ ~h~l ~e ~

W095/05554 2 1 6 9 1 9 2 - 8 - PCT/AU94/00453
forces the movable piston into the position shown and the volume of the pressurechamber increases to its ~i . This is achieved by 0-ring 29 pressing the
shim 31 onto the 0-ring 30 which presses the spacer ring 28 which presses the
circlip 26 onto the spacing ring stop 32 whose limit of travel is reached when
the spring 33 is fully compressed against the inverted spacing ring stop 34
which is resting upon the circular internal push-on fastener 36.
In figure 2, the fluid flow safety device is shown in the
condition that it will be in when an emergency shut-off has occurred. The
movable plug 16 has been forced onto the sealing means 10 at the end of the
sensor chamber 9 at the outlet orifice end.
The circular internal push-on fastener 36 which is immovable
within the chamber walls of the body, is anchoring the inverted spacing ring
stop 34 which has the upper end of the spring 33 pressing against it. The other
end of the spring has forced the spacing ring stop 32 to come to rest against
the step in the bore of the pressure chamber 42. The action of the still
tensioned spring which is held between the circular internal push-on fastener
and the step in the bore of the pressure chamber holds the movable piston
between the inverted spacing ring stop pressing against the movable piston's
extension at 43 and the spacing ring stop pressing onto the circlip 27. When
there are no external forces acting upon the movable piston 20, it returns
to this position. The plunger 39 does not touch the movable plug. The indicator
mark 38 is no longer visible and the volume of the pressure chamber returns
to its rest volume.
In figure 3, the fluid flow safety device is shown in the
condition that it will be in when it is being reset. The reset occurs when
an external force moves the movable piston into the position as shown. The
extension of the movable piston at 43 moves the inverted spacing ring stop
34 away from the circular internal push-on fastener 36 and compresses the spring33 against the spacing ring stop 32 which can not move as it is held in place
by the step in the bore of the pressure chamber 42. While held in this position,the volume of the pressure chamber decreases to, or near, its ni _ .
The plunger 39 has moved the movable plug 16 away from
the sealing means 10 and this action allows the pressure chamber to become
pressurized and, providing a sufficient pressure is obtained, returns the device to the condition as shown in figure 1.
In the drawings designated as figures 4, 5 and 6 there is
shown a horizontal version of a fluid flow safety device 44 which is connectableto a gas cylinder (not shown) at the inlet assembly 45 which, in this case
has a POL type mating connection, and connects with the body 46. In the version
SU~lllUl~ SED3Er ~ ~

~ 9 - 2 1 69 I q2
W O9S/05554 PCT/AU94/00453
shown in these figures the inlet assembly 45 is separate from, and connectable
to the body. As this version is not intended to be taken apart, an industrial
adhesive is used to bond the inlet assembly to the body.
Contained within the inlet assembly is an inlet passageway
48 which leads to a selective fluid flow sensor chamber 49 and a sealing means
50 which encircles the outlet orifice 51 of the sensor chamber which leads
to a pressure chamber 52 within the body. In these three drawings the sealing
means is shown as an 0-ring which is held in place with a removable tapered
sensor chamber passageway 53. A inlet passageway end stop 47 is pin which is
firmly inserted into the body. The inlet assembly can contain a filtering
material within its passageway to help ensure that foreign material is excluded
from the sensor chamber. The positioning of the movable plug 56 within the
sensor chamber herein defined by a larger diameter 57, a tapered section 58
and a smaller diameter 59 enhances the effects of Bernoulli's theorem on the
movable plug in that as the movable plug is drawn towards the outlet orifice
by the flow of the fluid, as the movable plug approaches the outlet orifice
the pressure increases until the seal with the sealing means is achieved. Also,
the tapered section allows for a much lower flow rate to move the movable plug
to the sealing means when the orientation of the sensor chamber is in a
horizontal alig --t. Thus, if the unit falls onto its side, it is very
responsive to a quick shut-off. The tapered sensor chamber passageway 53 is
removable from the body. In order to form a fluid tight seal between the sensor
chamber and the pressure chamber an 0-ring 54 surrounds the tapered sensor
chamber passageway and forms a seal between the body and the removable outlet
orifice 55 of the sensor chamber. The removable outlet orifice passageway holds
the tapered sensor chamber in place and, in turn, it is held in place by the
vented plug 201 which connects with the guide 202 which attaches to the body.
A passageway 203 leads to the outlet end for connection to further fluid
transport chAni! .
The guide forms part of the pressure chamber and, within
the guide hole 206, resides the movable piston 60 which has a circlip groove
61 and a circlip 65 located at its lower end. An angled stop 64, a spring 63
and spacer ring 204 are located between the circlip and the step in the piston
at 205. A step in the guide hole's chamber walls 207 limits the outward travel
of the spacer ring. The angled stop is able to travel between the vented plug
and the step in the guide hole's chamber walls at 208.
There is a groove 67 in the extension of the movable piston
which contains a indicator mark 88 which could be a green neoprene 0-ring.
Mounted onto the base of the movable piston is a plunger 69 which is of smaller
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WO 9S/05554 2 1 6 9 1 9 2 lo - PCT/AU94/00453
diameter that of the outlet orifice from the sensor chamber. To help ensure
that the device is tamper proof, the guide is screwed into the body with the
aid of an industrial strength adhesive.
The guide uses the 0-ring 209 to help ensure a fluid tight
seal between itself and the body while the two grooves on the movable piston
accommodate the two 0-rings 210 and 211.
For those variations of this presentation where an
additional shut-off -ch~n; ! iS used, the pin 47 is removed and is replaced
with a shut-off shaft and triggering merh~ni~ whose axes are aligned, with
the sensor chamber to a common datum. Under normal conditions, the shaft will
locate the movable plug in the position as shown in figure 4. When the
triggering -ch~ni! holding the shut-off shaft releases, the movable plug
is forced, by the shut-off shaft, to form a seal with the sealing means. To
reset the triggering ~-h~n;sm and to re-establish the fluid flow, the reset
action of the movable piston will not only cause the pin to unseat the movable
plug, but will travel sufficiently far to cause the shut-off shaft trigger
to re-latch into its armed state.
In figure 4, the fluid flow safety device is shown in the
condition that it will be in when it is passing pressurized fluid at a rate
below the ~; predetermined flow rate for that unit. The movable plug
is near the base of the sensor chamber and the pressure in the pressure chamber
forces the movable piston into the position shown and the volume of the
pressure chamber increases to its ~ . The upward travel of the movable
piston is limited by the circlip 65 pressing against the angled stop 64 which
has engaged the step in the guide hole~s chamber walls at 208. If the pressure
in the pressure chamber drops below a predetermined value, the tension in
the spring 63 returns the movable piston to its rest position. For the
horizontal version which incorporates an separate shut-off ~ch~n;s~, which
is not shown~ the pin 47 is removed and a shaft ~ch~n; is installed at
point 199. This shaft ~ch~n;! is axially Aligned with the axis of the sensor
chamber and when in it is held open by the triggering system, positions the
movable plug in the location as shown in this figure. When the triggering
system has been released, the shaft ~ch~n;! forces the movable plug to form
a seal with the sealing means thereby terminating the fluid flow.
In figure 5, the fluid flow safety device is shown in the
condition that it will be in when an emergency shut-off has occurred. The
movable plug 56 has been forced onto the sealing means 50 at the outlet orifice
end of the sensor chamber 49. As the pressure in the pressure chamber 52 has
fallen below a predetermined valve, the spring 63 pressing on the spacer ring
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11 21 691 92
W 095/05554 PCT/AU94100453
204 which is located on the step in the guide hole's chamber walls at 207
forces the movable piston 60 to travel to the point where the angled stop
64 rests upon the vented plug 201. When the movable piston is in this position,
the indicator mark 88 is not visible and the volume of the pressure chamber
returns to its rest volume.
In figure 6, an external force moves the movable piston to
its reset position. The spring 63 is compressed and the reset pin prevents
the movable plug from maintA;ning contact with the sealing means and the volume
of the pressure chamber is decreased to, or near, its ni
It should be noted that all of the devices described in
the figures 1 to 6, can be used to test a pipe system for leaks. When the line
has been pressurized and the fluid flow safety device has been reset, turn
the cylinder valve off. Leave the system for about an hour and then check
to see if the indicator mark is still visible. If it is not then a leak of
some kind is present.
In figure 7, the fluid flow safety device has been mounted
into a modified form of the standard type of on/off valve which is currently
marketed on LP gas cylinders. The body 101 has the standard features which
include an att~ching means 102 for connecting the valve body to the cylinder
(not shown) which normally consist of a tapered thread. An inlet passageway 103
which leads to a safety valve ~h~ni ! 104 through a safety valve passageway
105, a primary valve seat 106, a primary valve 107, an outlet passageway 108
and an outlet aperture 109 for connection to further fluid transport
-ch~nisms. An 80~ decanting bleed tube 110 and bleed valve 111 are provided
to aid the cylinder filling process. A valve -ch~ni_ including a handle
112, a spindle 113 and an att~hing guide housing 114 are standard features.
Many of the above mentioned features are covered by mandatory requirements and
it was therefore essential that the current invention made no attempt to
interfere with, or modify the operation or integrity of any of these features.
The provision of a selective fluid flow sensor chamber 115,
the sealing means 116, the tapered sensor chamber passageway 117, the rest
position locating means 118 for the movable plug 119, the sensor chamber shield
120 which isolates the internal length of the sensor chamber from all other
passageways and the axial ~lig --t of these components provides an efficient,
safe and consistent termination of the fluid flow from the open valve seat
when the predetermined flow rate has been exceeded regardless of whatever
fluid disch~rge may be occurring from any of the other orifices located in the
body. The tapered sensor chamber passageway and the rest position of the
movable plug make it virtually impossible to remove any gas from the cylinder
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W095105554 2 1 6 9 1 q 2 - 12 - PCTIAU94/00453
when the cylinder is in the horizontal position. A very low discharge rate
rolls the movable plug into contact with the sealing means and terminates the
fluid flow. Domestic and commercial LP gas appliances are designed to operate
on gas, not liquid fuel. The internal shape of the sensor chamber combined with
the movable plug make it very hard to obtain a substantial flow of gas unless
the cylinder is mounted in its correct orientation. This design has no critical
tilt angles. Any deviation from the vertical in any direction will cause the
~ ; flow rate to ~; n;sh. Also, the positioning of the movable plug into
its rest position by the aid of three fingers, provides a stable platform
for the refilling process in that there is n; ~1 pressure loss as the movable
plug ~. -in~ stationary during this procedure.
With this design, when the on/off valve is in the off
position, the pin 121 in the centre of the valve plug will not allow a seal
to form between the movable plug and the sealing means. As the primary valve
-ch~ni starts to open a small quantity of gas would be allowed to escape.
This discharge is sufficient to pressurize the gas lines, or, if the main
outlet is venting to the atmosphere, a further opening of the valve quickly
causes the movable plug to terminate the fluid flow. According to the length
of the pin, the termination should occur within the first twenty degrees of
rotation of the spindle when venting to the atmosphere. Also, with this design,
it is possible to unscrew and remove the primary valve -ch~ni ! from the
body regardless of the contents of the gas cylinder.
To reset the valve, it is a simple matter to turn the
primary valve fully off, which opens the movable plug, and then slowly turn
it back on to pressurize the line.
In figure 8, a fluid flow safety shut-off mech~ni ! iS
detailed. It is intended as a special upgrade for the cylinder type fluid
flow safety device herein previously described. This unit is intended to be
either a factory fit option or an upgrade kit for the after fit market. It
provides an indicator and reset mech~n;~ similar to those described in the
figures 1 to 6. The attach;ng guide housing 122 screws into the body of the
fluid flow safety device described in figure 7. A spindle 123 makes a threaded
connection with the attach;ng guide housing and has a handle 124 located at
the outer end and held in place with the aid of an indicator nut 125. Within
the spindle is a spindle guide hole which contained a reset shaft 126. Screwed
onto the outer end of the reset shaft is an extension 127 which includes an
indicator mark 128. Between the two ends of the both the spindle and the reset
shaft are two captured springs 129 and 130. These springs locate the reset
shaft into a central position in relation to the spindle.
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21 691 9~
W 095/05554 - 13 - PCT/AU94/00453
Located within, and making a sealing and sliding contact
with the att~ching guide housing is a movable piston which contains within
it a cylindrical chamber 132. Making a sliding and sealing contact within
that cylindrical chamber is a reset plunger pin 133. Sealing the lower end
~ 5 of the cylindrical chamber is a valve plug 134. The orifice where the reset
plunger pin passes through the valve plug is slightly oversized to allow
pressurizing of the cylindrical chamber to occur. If the mech~ni ! as detailed
within figure 8 were installed in a valve body, it would show the condition
of an emergency shut-off. The pressure in the pressure chamber has the movable
piston touching the spindle, the reset plunger pin is touching the reset
shaft, the spindle is in an open position and the indicator mark is not
visible.
In figure 9, a fluid flow safety shut-off --h~ni! is
detailed in the reset position. The spindle 123 has been rotated to a near
closed position and has moved the movable piston 131 to the lower end of the
att~ching guide housing 122. When the extension 127 has been depressed, the
spring 130 compresses and the reset plunger pin extends itself through the
valve plug 134. In this state, the reset plunger pin will deny seal to occur
between the movable lug and the sealing means.
In figure 10, a fluid flow safety shut-off ?chAni ! iS
detailed in its armed position. The spindle 123 has been rotated within the
attaching guide housing 122 to an open position. The pressure in the pressure
chamber has forced the movable piston 131 into the att~ching guide housing
and into contact with the spindle. The pressure within the cylindrical chamber
has forced the reset plunger pin 133 into its fully retracted position and
has forced the reset shaft 126 to compress the spring 129 and, the extension
127 is positioned so that the indicator mark 128 is visible.
It should be noted that this type of mech~ni ! also is
suitable the incorporation of a child proof lock which would deny access to
the flammable fluids for those people not skilled in the art of such devices.
~U~ lUl~ SEE3Er ~e

Representative Drawing