Teaching apparatus

摘要

A teaching apparatus especially for dyslectic students of the type wherein a platen carrying the work lesson is movable between a raised position in which the indicia on the worksheet is readily traceable by a student on tracing paper positioned over a window above the platen to a lowered position where the indicia on the worksheet gradually becomes indiscernible to the student. A bellows is moved to a collapsed position in response to movement of the platen to its raised position and the bellows is operative when extended to move the platen to its lowered position. Valve means are provided to selectively control the rate at which air is allowed to move back into the collapsed bellows to thereby control the rate of extension of the bellows and the rate at which the platen returns to its lowered position.