Air heater seal frame support link

In a regenerative air heater of the type having an open-ended cylindrical shell disposed about an elongated central axis with open axially spaced cylindrical end faces, a stationary heat exchange mass mounted within the shell, air ducts coaxially mounted at each end of the shell for rotation relative to the heat exchange mass, means for sealing the air ducts in fluid-tight engagement against the end faces, said sealing means including a seal frame, a hood frame axially spaced from the seal frame attached to each air duct, and an intermediate linkage connecting the seal frame and the hood frame, the improvement wherein the intermediate linkage comprises a first plate extending laterally, relative to the axis, from the seal frame, a second plate extending laterally from the hood frame, and link means pivotally supported by and maintaining the first and second plate in parallel relationship to each other for axial coplanar relative movement, the link means comprising a first link pivotally connected at one end to the first plate, and a second link pivotally connected at one end to the second plate and pivotally connected at an opposite end to an end of the first link opposite the end of the first link which is connected to the first plate.