Lever based grade vent valve

Abstract

A grade vent valve assembly includes a float moveable between a lowered position and a raised position. A lever is coupled to the float at a first end of the lever. The lever pivots about a fulcrum spaced from the first end in response to movement of the float between the raised position and the lowered position. The lever pivots between an open position when the float is in the lowered position, and a sealing position when the float is in the raised position. The lever seals an orifice when in the sealing position to block fluid flow through the orifice.

1 . A grade vent valve assembly for a fuel tank of a vehicle, the grade vent valve assembly comprising:
 a housing defining a float chamber, an inlet open to the float chamber, a liquid sealing chamber in fluid communication with the float chamber, and an orifice open to the liquid sealing chamber;   a float disposed within the float chamber and moveable between a lowered position and a raised position; and   a lever having a first end coupled to the float and extending across the orifice to a second end, wherein the lever pivots about a fulcrum between an open position allowing fluid communication between the orifice and the inlet and a sealing position blocking fluid communication between the orifice and the inlet in response to movement of the float between the lowered position and the raised position;   wherein the lever is disposed in the sealing position when the float is disposed in the raised position, and the lever is disposed in the open position when the float is disposed in the lowered position.   
     
     
         2 . A grade vent valve assembly as set forth in  claim 1  further comprising a biasing device disposed within the float chamber between the housing and the float and configured for biasing the float into the raised position. 
     
     
         3 . A grade vent valve assembly as set forth in  claim 1  wherein the fulcrum is disposed at an approximate midsection of the lever. 
     
     
         4 . A grade vent valve assembly as set forth in  claim 1  wherein the first end of the lever is coupled to the float at a first force application location and the orifice is positioned relative to the lever at a second force application location, and wherein the fulcrum is disposed a first distance from the first force application location and a second distance from the second force application location. 
     
     
         5 . A grade vent valve assembly as set forth in  claim 4  wherein the lever defines a length between the first force application location and the second force application location, and wherein the first distance is at least equal to or greater than ten percent (10%) of the length. 
     
     
         6 . A grade vent valve assembly as set forth in  claim 4  wherein the lever defines a length between the first force application location and the second force application location, and wherein the second distance is at least equal to or greater than ten percent (10%) of the length. 
     
     
         7 . A grade vent valve assembly as set forth in  claim 1  further comprising a sealing member attached to the lever adjacent the second end of the lever and moveable with the lever, wherein the sealing member is configured for sealing against an interior surface of the liquid sealing chamber to seal the orifice. 
     
     
         8 . A grade vent valve assembly as set forth in  claim 7  wherein the sealing member includes a ribbon disposed between the lever and the interior surface of the liquid sealing chamber and including a width greater than a width of the orifice. 
     
     
         9 . A grade vent valve assembly as set forth in  claim 7  wherein the sealing member includes and is manufactured from a pliable material. 
     
     
         10 . A grade vent valve assembly as set forth in  claim 9  wherein the pliable material includes a synthetic rubber material. 
     
     
         11 . A grade vent valve assembly as set forth in  claim 7  further comprising a locating mechanism interconnecting the sealing member and the housing and configured to position the sealing member relative to the orifice. 
     
     
         12 . A grade vent valve assembly as set forth in  claim 1  further comprising a pivotable connection interconnecting the lever and the housing and defining the fulcrum. 
     
     
         13 . A grade vent valve assembly as set forth in  claim 1  wherein the first end of the lever is pivotably connected to the float. 
     
     
         14 . A grade vent valve assembly as set forth in  claim 1  further comprising a pressure relief mechanism in fluid communication with the orifice and configured for venting pressurized vapors therethrough. 
     
     
         15 . A grade vent valve assembly as set forth in  claim 1  further comprising a cover attached to and in sealing engagement with the housing and further defining the float chamber and the liquid sealing chamber. 
     
     
         16 . A roll-over vent valve assembly for a fuel tank of a vehicle, the roll-over vent valve assembly comprising:
 a housing defining a float chamber, an inlet open to the float chamber, a liquid sealing chamber in fluid communication with the float chamber, and an orifice open to the liquid sealing chamber;   a float disposed within the float chamber and moveable between a lowered position and a raised position;   a biasing device disposed within the float chamber between the housing and the float and configured for biasing the float into the raised position   a lever having a first end pivotably coupled to the float and extending across the orifice to a second end, wherein the lever pivots about a fulcrum between an open position allowing fluid communication between the orifice and the inlet and a sealing position blocking fluid communication between the orifice and the inlet in response to movement of the float between the lowered position and the raised position;   wherein the lever is disposed in the sealing position when the float is disposed in the raised position, and the lever is disposed in the open position when the float is disposed in the lowered position;   a sealing member attached to the lever adjacent the second end of the lever and moveable with the lever, wherein the sealing member includes a synthetic rubber material and is configured for sealing against an interior surface of the liquid sealing chamber to seal the orifice;   a locating mechanism interconnecting the sealing member and the housing and configured to position the sealing member relative to the orifice;   a cover attached to and in sealing engagement with the housing and further defining the float chamber and the liquid sealing chamber.   
     
     
         17 . A roll-over vent valve assembly as set forth in  claim 16  wherein the first end of the lever is coupled to the float at a first force application location and a center of the orifice is positioned relative to the lever at a second force application location, wherein the fulcrum is disposed a first distance from the first force application location and a second distance from the second force application location, wherein the lever defines a length between the first force application location and the second force application location, and wherein the first distance is at least equal to or greater than ten percent (10%) of the length, and the second distance is at least equal to or greater than ten percent (10%) of the length. 
     
     
         18 . A roll-over vent valve assembly as set forth in  claim 16  wherein the fulcrum is disposed at an approximate midsection of the lever. 
     
     
         19 . A roll-over vent valve assembly as set forth in  claim 16  further comprising a pivotable connection interconnecting the lever and the housing and defining the fulcrum. 
     
     
         20 . A roll-over vent valve assembly  20  as set forth in  claim 16  further comprising a pressure relief mechanism  26  in fluid communication with the orifice  36  and configured for venting pressurized vapors therethrough.