Resilient flush tank valve and water level indicator

Claim 1

A WATER FILLABLE AND DRAINABLE FLUSH TANK CONSTRUCTION COMPRISING: A WALLED TANK HAVING A BOTTOM WALL PROVIDED WITH OUTLET MEANS EMBODYING A GRAVITY FLOW ELBOW, SAID OUTLET MEANS BEING ADAPTED TO BE OPERATIVELY COMMUNICATIVELY CONNECTED AT A DISCHARGE END WITH A COMPLEMENTAL TOILET BOWL, SAID OUTLET MEANS HAVING A PORTION WITHIN THE INTERIOR OF SAID TANK PROVIDED WITH A VALVE SEAT, AN UPSTANDING TANK WATER OVERFLOW PIPE IN SAID TANK JOINED AT ITS LOWER END TO SAID ELBOW, A FLAP VALVE NORMALLY ATOP SAID SEAT AND CLOSING THE OUTLET MEANS, SAID FLAP VALVE BEING FLEXIBLE AND ALSO RESILIENT, A SHAFT ROCKABLE IN A BEARING PROVIDED THEREFOR ON A FRONT WALL OF SAID TANK, A HAND OPERATED TIP MEMBER MOUNTED ON SAID SHAFT AND LOCATED EXTERIORLY OF SAID FRONT WALL, AN ELONGATED LEVER IN SAID TANK, THE MAJOR PORTION OF SAID LEVER BEING DISPOSED IN AN OPERATING PLANE BELOW THE PLANE OF THE UPPER END OF SAID OVERFLOW PIPE AND HAVING ONE END OPERATIVELY CONNECTED WITH SAID SHAFT, THE OTHER END BEING FREE, TERMINATING ADJACENT TO SAID OVERFLOW PIPE AND PROVIDED WITH TERMINAL GUIDE MEANS GUIDINGLY EMBRACING AND MOVABLY OPERABLE RELATIVE TO SAID UPSTANDING OVERFLOW PIPE, A NORMALLY TAUT FLEXIBLE ELEMENT BETWEEN AND CONNECTED AT A LOWER END WITH A LIFTABLE AND LOWERABLE END PORTION OF SAID FLAP VALVE AND ORIENTED WITH SAID OVERFLOW PIPE AND CONNECTED