Method and arrangement of a flight attachment

Abstract

Flights in drums of drying and mixing apparatus are attached with bolts held by bolt cages disposed on inner surfaces of the drums. The bolt cages are formed of channels, the channel openings of which face the inner surface of the drums, and which channels have longitudinal slots extending from ends of the channels into the bases thereof for receiving the shanks of bolts. The bases or base plates are consequently spaced by side walls of the channels from the inner surfaces of the drums, the depth of the channels being such to admit the height of a head of a bolt between the inner surface of the drums and adjacent and facing surfaces of the bases of the channel type cages. The side walls of the cages extend parallel to the slots and are spaced to slidingly accept the width of the head of a bolt across opposite parallel faces of such bolt. The spacing between the sidewalls thereby prevents the rotation of a caged bolt about its longitudinal axis as a result of a nut being torqued onto its shank. The cages are preferably welded to the inside surfaces of the drums and releasably capture the heads of bolts inserted into the slots with the shanks of the bolts extending radially inward into the drums to engage correspondingly located apertures in flanges of flights to be attached. When an apertured flange of any such flight is inserted over respective cages and bolts, and is fastened to the cages by complementary fasteners, such as nuts, the profile of the cage in combination with a protective shielding by the flange of the attached flight substantially eliminates wear on the cages due to material contact as a result of the operation of a respective drum.