Apparatus for operating offtake and main valves

A coke oven gas apparatus for consecutive operation of a seal on a gas collection main conduit and a cover of a communicating gas offtake pipe, said gas offtake pipe having a vertical axis and having said cover at its top and also communicating through a transition element to a horizontally presented gas collection main conduit, the said seal being disposed to open or close the connection from said transition element to said gas collection main conduit, comprising

• an extensible and retractable first shaft connected through a first pivot pin at its upper end to the bottom end of a second shaft;
• said second shaft connected at its upper end to one end of a first bell crank arm which has a second pivot pin at its center and is connected to the said cover whereby pivotal movement of the said first bell crank arm will move the said cover from an open position to a closed position and vice versa, the other end of said first bell crank arm being weighted to urge the said cover by gravity into a closed position;
• said first pivot pin being engaged in a slot in one arm of a second bell crank arm having its other arm secured to the said seal whereby movement of the said second bell crank arm about the said first pivot pin causes the said seal to open and close and vice versa;
• the connections being such that with the said first shaft in its extended, uppermost position, the said cover is closed and the said seal is open and with the said first shaft in its retracted, bottommost position, the said cover is open and the said seal is closed;
• said shafts, pivot pins and arms being arranged and constructed such that as the said first shaft extends from its lowermost position, said cover closes and thereafter said seal opens, and as the said first shaft retracts from its uppermost position, the said seal closes and thereafter the said cover opens.