Flush valve structure for a toilet tank

Abstract

A toilet tank flush valve structure, for use with a toilet tank having a floor formed with an opening, includes a base for installation in the opening formed in the floor of the toilet tank. The base defines a water outflow passage having an upper end at which the passage has an area A1 and a lower end at which the passage has an area A2 and includes a valve seat at the upper end of the water outflow passage. A flush valve is movable relative to the base between a sealing position in which the valve engages the valve seat in sealing relationship and a flushing position in which the valve is spaced upwardly from the valve seat. The area A1 is substantially greater than the area A2.

1 - 14 . (canceled) 
   
   
       15 . A toilet tank installation including a toilet tank having a floor formed with an opening and a flush valve assembly comprising:
 a base structure comprising a base portion installed in the opening formed in the floor of the toilet tank, and an offset portion extending upward into the tank from the base portion, the base structure defining a water outflow passage having an upper end and a lower end, the lower end of the outflow passage being offset horizontally from the upper end of the outflow passage, and the base structure including a first valve seat at the upper end of the water outflow passage, wherein said offset portion provides the offset of the lower end of the outflow passage from the upper end of the outflow passage,   a guide member that extends vertically upward from the base structure,   a lower flush valve float device that is movable relative to the base structure between a sealing position in which the lower flush valve float device engages the first valve seat in sealing relationship and a flushing position in which the lower flush valve float device is spaced upwardly from the first valve seat, the lower flush valve float device defining a water flow passage that extends downward through the lower flush valve float device from an opening bounded by a second valve seat at an upper end of the lower flush valve float device to an opening at a lower end of the lower flush valve float device, and wherein the guide member passes through the water flow passage of the lower flush valve float device, whereby the guide member guides movement of the lower flush valve float device relative to the base structure, and the opening at the lower end of the lower flush valve float device is defined by an outflow extension tube that is part of the lower flush valve float device and extends downward beyond the first valve seat when the lower flush valve float device engages the first valve seat, and   an upper flush valve float device that is movable relative to the lower flush valve float device between a sealing position in which the upper flush valve float device engages the second valve seat in sealing relationship and a flushing position in which the upper flush valve float device is spaced upwardly from the second valve seat, the upper flush valve float device defining a passage that extends vertically through the upper flush valve float device, and wherein the guide member passes through the passage of the upper flush valve float device, whereby the guide member guides movement of the upper flush valve float device relative to the lower flush valve float device,   and wherein the offset portion is a skewed frusto-conical extension that flares upwardly from the base portion.   
   
   
       16 . A toilet tank installation according to  claim 15 , wherein the offset portion defines a segment of the water outflow passage,
 and wherein said segment of the water outflow passage has an upper end and a lower end, the first valve seat is provided at the upper end of said segment of the water outflow passage, and the upper end of said segment of the water outflow passage is of greater diameter than the lower end of said segment of the water outflow passage.   
   
   
       17 . A toilet tank flush valve assembly, for use with a toilet tank having a floor formed with an opening, the flush valve assembly comprising:
 a base structure comprising a base portion for installation in the opening formed in the floor of the toilet tank, and an offset portion extending upward into the tank from the base portion, the base structure defining a water outflow passage having an upper end and a lower end, the lower end of the outflow passage being offset horizontally from the upper end of the outflow passage, and the base structure including a first valve seat at the upper end of the water outflow passage, wherein said offset portion provides the offset of the lower end of the outflow passage from the upper end of the outflow passage,   a guide member that extends vertically upward from the base structure,   a lower flush valve float device that is movable relative to the base structure between a sealing position in which the lower flush valve float device engages the first valve seat in sealing relationship and a flushing position in which the lower flush valve float device is spaced upwardly from the first valve seat, the lower flush valve float device defining a water flow passage that extends downward through the lower flush valve float device from an opening bounded by a second valve seat at an upper end of the lower flush valve float device to an opening at a lower end of the lower flush valve float device, and wherein the guide member passes through the water flow passage of the lower flush valve float device, whereby the guide member guides movement of the lower flush valve float device relative to the base structure, and the opening at the lower end of the lower flush valve float device is defined by an outflow extension tube that is part of the lower flush valve float device and extends downward beyond the first valve seat when the lower flush valve float device engages the first valve seat, and   an upper flush valve float device that is movable relative to the lower flush valve float device between a sealing position in which the upper flush valve float device engages the second valve seat in sealing relationship and a flushing position in which the upper flush valve float device is spaced upwardly from the second valve seat, the upper flush valve float device defining a passage that extends vertically through the upper flush valve float device, and wherein the guide member passes through the passage of the upper flush valve float device, whereby the guide member guides movement of the upper flush valve float device relative to the lower flush valve float device.   
   
   
       18 . A flush valve assembly according to  claim 17 , wherein the base structure further includes an upward extension element extending upward beyond the offset portion, and the first valve seat is provided at an upper end of the upward extension element. 
   
   
       19 . A flush valve assembly according to  claim 18 , wherein the water outflow passage has an upper segment defined by the upward extension element, and the upper segment of the water outflow passage tapers downwardly. 
   
   
       20 . A flush valve assembly according to  claim 18 , wherein the outflow extension tube extends downward into the upward extension element. 
   
   
       21 . A flush valve structure according to  claim 17 , wherein the offset portion is an S-shaped tube. 
   
   
       22 . A toilet tank flush valve assembly, for use with a toilet tank having a floor formed with an opening, the flush valve assembly comprising:
 a base structure comprising a base portion for installation in the opening formed in the floor of the toilet tank, and an offset portion extending upward into the tank from the base portion, the base structure defining a water outflow passage having an upper end and a lower end, the lower end of the outflow passage being offset horizontally from the upper end of the outflow passage, and the base structure including a first valve seat at the upper end of the water outflow passage, wherein said offset portion provides the offset of the lower end of the outflow passage from the upper end of the outflow passage,   a guide member that extends vertically upward from the base structure,   a lower flush valve float device that is movable relative to the base structure between a sealing position in which the lower flush valve float device engages the first valve seat in sealing relationship and a flushing position in which the lower flush valve float device is spaced upwardly from the first valve seat, the lower flush valve float device defining a water flow passage that extends downward through the lower flush valve float device from an opening bounded by a second valve seat at an upper end of the lower flush valve float device to an opening at a lower end of the lower flush valve float device, and wherein the guide member passes through the water flow passage of the lower flush valve float device, whereby the guide member guides movement of the lower flush valve float device relative to the base structure, and the opening at the lower end of the lower flush valve float device is defined by an outflow extension tube that is part of the lower flush valve float device and extends downward beyond the first valve seat when the lower flush valve float device engages the first valve seat, and   an upper flush valve float device that is movable relative to the lower flush valve float device between a sealing position in which the upper flush valve float device engages the second valve seat in sealing relationship and a flushing position in which the upper flush valve float device is spaced upwardly from the second valve seat, the upper flush valve float device defining a passage that extends vertically through the upper flush valve float device, and wherein the guide member passes through the passage of the upper flush valve float device, whereby the guide member guides movement of the upper flush valve float device relative to the lower flush valve float device,   and wherein the offset portion is a skewed frusto-conical extension that flares upwardly from the base.   
   
   
       23 . A flush valve assembly according to  claim 22 , wherein the offset portion defines a segment of the water outflow passage,
 and wherein said segment of the water outflow passage has an upper end and a lower end, the first valve seat is provided at the upper end of said segment of the water outflow passage, and the upper end of said segment of the water outflow passage is of greater diameter than the lower end of said segment of the water outflow passage.