Toilet tank flush valve

Claim 1

A TOILET TANK FLUSH VALVE, COMPRISING: A HOLLOW BODY HAVING AN OUTLET IN A LOWER PORTION THEREOF FOR THE DISCHARGE OF FLUSHING WATER THERETHROUGH, AN INLET FOR TANK OVERFLOW WATER IN AN UPPER PORTION THEREOF, AND AN OVER FLOW PASSAGE ESTABLISHING COMMUNICATION BETWEEN SAID INLET AND OUTLET, SAID BODY HAVING A BALL VALVE SEAT IN SAID UPPER PORTION DISPOSED ABOVE AND VERTICALLY ALIGNED WITH SAID OUTLET, SAID SEAT BEING INCLINED RELATIVE TO A HORIZONTAL LINE DISPOSED AT RIGHT ANGLES TO THE AXIS OF SAID OUTLET; A BOSS ON SAID BODY LOCATED BETWEEN SAID INLET AND SAID VALVE SEAT; A LEVER; MEANS PIVOTALLY MOUNTING SAID LEVER UPON SAID BOSS, SAID LEVER HAVING ARMS EXTENDING IN OPPOSITE DIRECTIONS FROM SAID PIVOT MEANS AND EACH TERMINATING IN A FREE END; A BALL VALVE MOUNTED UPON THE FREE END OF ONE OF SAID ARMS; A COUNTERWEIGHT MOUNTED UPON THE FREE END OF THE OTHER OF SAID ARMS, SAID OTHER ARM INCLUDING A LATERALLY EXTENDING PORTION CONNECTING THE SAME WITH SAID ONE ARM AND ARRANGED SO THAT SAID OTHER ARM IS DISPOSED TO ONE SIDE OF SAID INLET OPENING; AND MEANS ON SAID ONE ARM CONNECTIBLE WITH ACTUATING MEANS FOR LIFTING SAID VALVE ELEMENT FROM ITS SEAT.