Safety valve

• US 6,408,869 B1
• Filed: 07/02/2001
• Issued: 06/25/2002
• Est. Priority Date: 08/07/2000
• Status: Expired due to Fees

• Current Assignee: Taiwan Pao
• Original Assignee: Gaap Gas Controls, LLC
• Inventors: Grewal, Harsharan, Bartos, Josef A.
• Primary Examiner(s): Walton, George L.
• Application Number:
  US09/895,705
• Time in Patent Office: 358 Days
• Field of Search: 137/413, 137/414, 137/442, 137/443, 137/444, 137/446, 137/430, 141/198
• US Class Current: 137/414
• CPC Class Codes: F16K 1/303 with a valve member, e.g. stem or shaft, passing through the seat
• CPC Class Codes: F16K 1/307 Additional means used in combination with the main valve
• CPC Class Codes: F16K 31/34 acting on pilot valve controlling the cut-off apparatus
• CPC Class Codes: F16K 31/385 the fluid acting on a diaphragm
• CPC Class Codes: F17C 2250/0413 with floats
• CPC Class Codes: Y10T 137/7374 Flexible diaphragm valve
• CPC Class Codes: Y10T 137/7426 Float co-axial with valve or port
• CPC Class Codes: Y10T 137/7478 With interposed cam, gear or threaded connection

Abstract

A liquid level responsive shut-off valve for filling a tank, such as a liquid propane tank, comprises a valve housing having an inlet passageway for connection to a source of liquid under pressure, an outlet passageway opening into the tank, and a diaphragm actuated valve element having open and closed positions respectively opening and closing. the inlet passageway to the flow of liquid therethrough to the outlet passageway and tank. A float operated valve element controls operation of the diaphragm actuated valve element and has a closed position when the tank is initially filled which precludes the flow of liquid into the tank thereafter, even when the tank becomes empty, until the liquid supply pressure is reduced to atmosphere.

Claims

1. A liquid level responsive shut-off valve comprising a valve housing having a first end and an inlet passageway at said first end for connection to a source of liquid under pressure, said inlet passageway having an axis and an outlet end transverse to said axis, a diaphragm actuated valve element coaxial with said axis for opening and closing said outlet end, a spring biasing said diaphragm actuated valve element to open said outlet end, said housing including an outlet passageway laterally adjacent said outlet end for the flow of liquid from said housing when said outlet end of said inlet passageway is open, said diaphragm actuated valve element having a first side facing said outlet end of said inlet passageway and a second side opposite said first side, said housing including a liquid chamber on said second side coaxial with said axis and an outlet port for the flow of liquid in said chamber from said housing, said diaphragm actuated valve element including a flow passageway between said first and second sides and having an inlet end in flow communication with said inlet passageway and an outlet end in flow communication with said liquid chamber, said housing having a second end spaced from said first end, a float retainer mounted on said second end of said housing coaxial with said axis and providing a float chamber having an inner end adjacent said second end of said housing, a float in said float chamber, a float operated lever pivotally mounted in said float chamber between said float and said inner end of said float chamber, a lever operated valve element in said valve housing having open and closed positions for respectively opening and closing said outlet port to the flow of liquid from said liquid chamber through said outlet port in response to the position of said float in said float chamber, said lever operated valve element including an operating end extending from said housing into said float chamber, said lever having an actuating end and an opposite end spaced from said actuating end, said actuating end interengaging with said operating end of said lever operated valve element, said opposite end of said lever slidably engaging said float for said float to pivot said lever as the float ascends and descends in said float chamber, said float at a predetermined lower level in said float chamber engaging said opposite end of said lever for said actuating end of said lever to interengage with said operating end of said lever operated valve element to maintain said lever operated valve element in said open position thereof, whereby liquid under pressure from said source flows through said inlet passageway and through said flow passageway into said liquid chamber and out through said outlet port, said actuating end of said lever disengaging said operating end of said lever operated valve element when said float ascends in said float chamber to a predetermined upper level, whereby said lever operated valve element is released to close said outlet port and liquid under pressure flowing into said liquid chamber through said flow passageway from said inlet passage closes said diaphragm actuated valve element, and said actuating end of said lever including means interengaging with said operating end of said lever operated valve element when said float ascends in said float chamber to said predetermined upper level and the outlet port is closed, the weight of said lever being insufficient to displace said lever operated valve element against the fluid pressure in said fluid chamber to open said outlet port, whereby said means interengaging with said operating end maintains the float operated lever against displacement relative to said operating end as said float descends in said float chamber from said upper level and until said liquid under pressure in said liquid chamber and said inlet passageway is reduced to atmospheric pressure whereupon the weight of said lever displaces said lever operated valve element to open said outlet port.

2. A liquid level responsive shut-off valve comprising a valve housing having a first end and an inlet passageway at said first end for connection to a source of liquid under pressure, said inlet passageway having an axis and an outlet end transverse to said axis, a pressure actuated valve element coaxial with said axis for opening and closing said outlet end, a spring biasing said pressure actuated valve element to open said outlet end, said housing including an outlet passageway laterally adjacent said outlet end for the flow of liquid from said housing when said outlet end of said inlet passageway is open, said pressure actuated valve element having a first side facing said outlet end of said inlet passageway and a second side opposite said first side, said housing including a liquid chamber on said second side coaxial with said axis and an outlet port for the flow of liquid in said chamber from said housing, said pressure actuated valve element including a flow passageway between said first and second sides and having an inlet end in flow communication with said inlet passageway and an outlet end in flow communication with said liquid chamber, said housing having a second end spaced from said first end, a float retainer mounted on said second end of said housing coaxial with said axis and providing a float chamber having an inner end adjacent said second end of said housing, a float in said float chamber, a float operated lever pivotally mounted in said float chamber between said float and said inner end of said float chamber, and a lever operated valve element in said valve housing having open and closed positions for respectively opening and closing said outlet-port to the flow of liquid from said liquid chamber through said outlet port in response to the position of said float in said float chamber, said lever operated valve element including a conical operating end extending from said housing into said float chamber, said lever having cam means at one end thereof and an opposite end spaced from said one end, said cam means interengaging with said conical operating end of said lever operated valve element for displacing said lever operated valve element to open and close said outlet port, said opposite end of said lever slidably engaging said float for said float to pivot said lever as the float ascends and descends in the float chamber, said float at a predetermined lower level in said float chamber engaging said opposite end of said lever for said cam means to interengage with said conical operating end of said lever operated valve element to maintain said lever operated valve element in said open position thereof, whereby liquid under pressure from said source flows through said inlet passageway and through said flow passageway into said liquid chamber and out through said outlet port, said cam means on said lever disengaging said conical operating end of said lever operated valve element when said float ascends in said float chamber to a predetermined upper level, whereby said lever operated valve element is released to close said outlet port and liquid under pressure flowing into said liquid chamber through said flow passageway from said inlet passage closes said diaphragm actuated valve element, and said cam means including a nose portion interengaging with said conical operating end in said closed position of said lever operated valve element and in response to said float ascending in said float chamber to said predetermined upper level, the weight of said lever being insufficient to displace said lever operated valve element against the fluid pressure in said fluid chamber to open said outlet port, whereby said nose portion interengaging with said conical operating end maintains the float operated lever against displacement relative to said conical operating end as said float descends in said float chamber from said upper level and until said liquid under pressure in said liquid chamber and said inlet passageway is reduced to atmospheric pressure whereupon the weight of said lever displaces said lever operated valve element to open said outlet port.

3. A liquid level responsive shut-off valve comprising a valve housing having an inlet passageway for connection to a source of liquid under pressure, an outlet passageway, a diaphragm actuated valve element having open and closed positions respectively opening and closing said inlet passageway to the flow of liquid therethrough to said outlet passageway, said diaphragm actuated valve element having upstream and downstream sides, said inlet and outlet passageways being on said upstream side, a liquid chamber on said downstream side, said diaphragm actuated valve element including a connecting passageway between said upstream side and said chamber, an outlet port for said chamber, a float operated valve element having open and closed positions respectively opening and closing fluid flow communication from said chamber to said outlet port, means including a float and float operated means for displacing said float operated valve element to said closed position thereof when said float is at a predetermined upper level relative to said float operated valve element, said float operated means being between and constantly engaging said float and said float operated valve element, said float at a predetermined lower level in said float chamber engaging said float operated means for said float operated means to interengage with said float operated valve element to maintain said float operated valve element in said open position thereof, whereby liquid under pressure from said source flows through said inlet passageway and through said connecting passageway into said liquid chamber and out through said outlet port, said float operated means disengaging said float operated valve element when said float ascends in said float chamber to said predetermined upper level, whereby said float operated valve element is released to close said outlet port and liquid under pressure flowing into said liquid chamber through said flow passageway from said inlet passage closes said diaphragm actuated valve element, said float operated means being in a first position when said float operated valve element is in said closed position thereof and said float is at said predetermined upper level, said float operated means and said float operated valve element including holding means interengaging in said closed position of said float operated valve element and in response to said float ascending to said predetermined upper level, the weight of said float operated means being insufficient to displace said float operated valve element against the fluid pressure in said fluid chamber to open said outlet port, whereby said holding means maintains the float operated means against displacement relative to said float operated valve element as said float descends from said upper level and until said liquid under pressure in said liquid chamber and said inlet passageway is reduced to atmospheric pressure whereupon the weight of said float operated means displaces said float operated valve element to open said outlet port.

4. A valve according to claim 3, wherein said float operated means includes a lever pivotal by said float about a lever axis to displace said float operated valve element from said open to said closed position.

5. A valve according to claim 4, wherein said lever has a first position when said float operated valve element is in said closed position, said lever including a nose and said float operated valve element including an end interengaging with said nose in said closed position of said float operated valve element for maintaining the said lever in said first position thereof.