There are provided a flush water tank apparatus capable of reducing a pressure of flush water in a pressure chamber easily, and a flush toilet apparatus provided with the same. A discharge valve hydraulic drive portion of a flush water tank apparatus includes a cylinder in which supplied the flush water flows, a piston that is slidably disposed in the cylinder, partitions inside of the cylinder into a pressure chamber and a back pressure chamber, and further is moved from a first position to a second position by a pressure of the flush water that has flowed into the pressure chamber, an outflow portion from which the flush water in the cylinder flows out, and a communication mechanism that establishes communication between the pressure chamber and the outflow portion after the clutch mechanism is disengaged.

There are provided a flush water tank apparatus capable of reducing a pressure of flush water in a pressure chamber easily, and a flush toilet apparatus provided with the same. A discharge valve hydraulic drive portion of a flush water tank apparatus includes a cylinder in which supplied the flush water flows, a piston that is slidably disposed in the cylinder, partitions inside of the cylinder into a pressure chamber and a back pressure chamber, and further is moved from a first position to a second position by a pressure of the flush water that has flowed into the pressure chamber, an outflow portion from which the flush water in the cylinder flows out, and a communication mechanism that establishes communication between the pressure chamber and the outflow portion after the clutch mechanism is disengaged.

There is provided a flush water tank apparatus capable of returning to a state where next toilet flush operation can be started in a short time while opening a discharge valve using a water supply pressure. A flush water tank apparatus (4) includes a reservoir tank (10), a discharge valve (12), a discharge valve hydraulic drive portion (14) configured to drive the discharge valve using a water supply pressure, and a discharge/vacuum break valve device (30) provided on an upstream side of the discharge valve hydraulic drive portion and configured to supply the water supplied from the upstream side to the discharge valve hydraulic drive portion on a downstream side. The discharge valve hydraulic drive portion includes a cylinder (14a) into which the water from the discharge/vacuum break valve device flows, and a piston (14b) configured to be moved by a pressure of the water flowing into the cylinder to move the discharge valve. The discharge/vacuum break valve device includes a valve body that operates to discharge the water flowing backward from the discharge valve hydraulic drive portion while opening the upstream side to an atmosphere when the supply of the water from the upstream side is stopped.

Some embodiments include a fluid control system with an outlet valve assembly, an inlet valve assembly including a venturi inlet valve, and an actuator coupled to the inlet valve assembly. In some embodiments, the actuator can enable a user to control a flush volume of fluid control system. Some embodiments include a moveable float positioned in a chamber of the outlet valve assembly, where the chamber includes a variably-sized upper portion with a volume that is based at least in part on a variable position of the moveable float in the chamber. Some embodiments include a adjustable control valves coupled to an outer surface of the outlet valve assembly and the inlet valve assembly. Some embodiments also include a bellows positioned in and coupled to the variably-sized upper portion. In some embodiments, the bellows are fluidly coupled to the venturi inlet valve and at least one of the control valves.

There are provided a flush water tank apparatus capable of accurately setting the amount of flush water to be discharged while opening a discharge valve by a discharge valve hydraulic drive unit. A flush water tank apparatus includes a valve controller, where, in a case where a first amount of flush water is selected, the valve controller causes the timing control mechanism to be engaged with the discharge valve and causes the timing control mechanism to operate such that engagement is released after a lapse of a first period of time, and in a case where a second amount of flush water is selected, the valve controller causes the timing control mechanism to be engaged with the discharge valve and causes the timing control mechanism to operate such that engagement is released after lapse of a second period of time shorter than the first period of time.

The flush water tank apparatus of the present invention includes: a clutch mechanism 30 coupling the discharge valve 12 and the discharge valve hydraulic drive unit 14 to pull up the discharge valve, and being disconnected at a predetermined timing to cause the discharge valve to descend; flush water amount selection device capable of selecting from a first and a second amounts of flush water; a float device 26 including a float and a holding mechanism switchable between a holding and a non-holding states in conjunction with movement of the float; and a timing control mechanism controlling a timing of a drain port 10a being blocked; and, when the second amount is selected, causes the second amount of flush water to be discharged by switching the holding mechanism to the non-holding state before a water level in a storage tank drops to a predetermined water level.

The present invention is a flush water tank apparatus (4) and includes: a storage tank (10) on which a drain port (10a) is formed, a discharge valve (12) opening/closing the drain port; a discharge valve hydraulic drive unit (14) driving the discharge valve using water supply pressure; a clutch mechanism (30) coupling the discharge valve and the discharge valve hydraulic drive unit to pull up the discharge valve; flush water amount selection device capable of selecting between a first and a second amount of flush water; a timing control mechanism controlling a timing of the drain port being blocked; and a control jet unit (20) jetting, when the second amount is selected, flush water to a water receiving surface provided on the timing control mechanism so that a timing of the drain port being blocked is earlier than a case of the first amount of flush water.

A flush water tank apparatus enabling accurately setting an amount of flush water to be discharged while opening a discharge valve via a discharge valve hydraulic drive unit and a flush toilet apparatus including the flush water tank are provided. A flush water tank apparatus includes a first float device; a second float device that prevents from descent of the discharge valve according to the water level so as to discharge a second amount of flush water; and an adjustment mechanism configured so that when the second amount of flush water is selected by the flush water amount selection portion the clutch mechanism is disconnected at a pull-up height of the discharge valve such that the discharge valve descended by the disconnection of the clutch mechanism is held by the second float device in a holding state.

Flush valve assemblies are described herein which include a valve body; a flush valve cover detachably connected to a flush line; a pivot mechanism capable of opening and closing the flush valve cover upon actuation; wherein the flush line is connected at a first end to a flush actuating device and at a second end to the flush valve cover, the line being capable of raising and lowering the cover upon actuation; and a float situated above the cover and connected to the flush line at a point between the first and the second ends of the flush line or by a separate float line connected to the cover. The float is sufficiently buoyant and capable of resisting the force of flowing water and keeping the flush valve cover open to allow flush water to pass through the valve body before closing the cover when the valve body is installed on a toilet.

Flush valve assemblies are described herein which include a valve body; a flush valve cover detachably connected to a flush line; a pivot mechanism capable of opening and closing the flush valve cover upon actuation; wherein the flush line is connected at a first end to a flush actuating device and at a second end to the flush valve cover, the line being capable of raising and lowering the cover upon actuation; and a float situated above the cover and connected to the flush line at a point between the first and the second ends of the flush line or by a separate float line connected to the cover. The float is sufficiently buoyant and capable of resisting the force of flowing water and keeping the flush valve cover open to allow flush water to pass through the valve body before closing the cover when the valve body is installed on a toilet.