Scanning device for a magnetic tape instrument

Claim 1

A scanning device, for use in a magnetic instrument of the type using a longitudinal tape for diagonal track scanning, comprising, in combination: a two-part stationary guide drum having a central axis concentric with said drum parts; a head assembly supported inside said guide drum rotatably about an axis of rotation, and including a head wheel, bearing means rotatably supporting said head assembly, said bearing means including a bearing near said head wheel, and a motor operable to drive said head assembly about said axis of rotation, the tape being movable in the vicinity of said head wheel at a predetermined angle of inclination relative to said axis of rotation; bearing adjusting means operable to move said bearing radially to concentrically align said axis of rotation with said central axis, said bearing adjusting means comprising three radially spaced apart adjusting elements, at least one of which has means for resiliently urging it towards said axis of rotation, an annular element for axially retaining, said bearing near said head wheel; and axial thrust bearing means disposed between said bearing near said head wheel and said element to facilitate smooth centering of said bearing with respect to said guide drum by consecutively adjusting said bearing adjusting means.