Abstract: To seal against the surround of the door opening of a coke oven, the door has an elongate knife-edge element which engages the surround and is held against a sealing surface on the side of the door. The knife edge element is movable past the sealing surface on the door for adjustment. The knife-edge element is divided into a plurality of mutually abutting parts in the adjustment direction. In order to allow a greater amount of adjustment of the knife edge element and to make assembly of the seal easier, holding means e.g. a plurality of brackets, are provided to hold the parts of the knife edge together in the adjustment direction and to restrain at least the outermost part from lateral movement relative to the door. The holding means permits relative sliding of the parts in the longitudinal direction.

Abstract: A drill rig for drilling wells having a derrick adapted to hold and lower a conductor string and drill pipe string. A support frame is fixed to the derrick to extend over the well to be drilled, and a rotary table, for holding and rotating drill pipe strings, is movably mounted thereon. The table is displaceable between an active position in alignment with the axis of the well and an inactive position laterally spaced therefrom. A drill pipe holder is movably mounted on the frame below the rotary table for displacement between a first position laterally of the axis of the well and a second position in alignment with the axis of the well. The rotary table and said drill pipe holder are displaced in opposition to each other, so that the rotary table may be removed from alignment with the axis of the well and said drill pipe string simultaneously held without removal from said well.