Mechanism for moving a magnetic head

Claim 1

A mechanism for displacing a magnetic head, the mechanism comprising: a chassis; a motor attached to the chassis; a lead screw mounted to be rotated by the motor around an axis thereof in a first and second direction; a guide shaft means attached to the chassis in parallel with the lead screw; a carriage carrying a magnetic head thereon and being supported by the guide shaft means so as to be translationally displaceable in a first or second direction along which the guide shaft means extends; a connecting cam body between the carriage and lead screw for converting the rotational displacement of the lead screw around the axis thereof into a translational displacement of the carriage, the connecting cam body being attached at one end thereof to a plate fixed to the carriage rotatable in a first direction around an axis located at a position between the lead screw and the guide shaft means substantially perpendicular to a plane including the lead screw and guide shaft means, and having at another end thereof, cam tooth means engaged with the lead screw to define a line of engaging contacts therebetween; an elastic means disposed between the connecting cam body and the carriage for pressing the cam tooth means of the connecting cam body against the lead screw to press the carriage against the guide shaft means; a pair of protruding portions, with one of the pair of protruding portions formed on a face of the connecting cam body adjacent said plate and the other of the pair of protruding portions on a face of the connecting cam body opposite to the face adjacent said plate; and means for enabling pivoting of the connecting cam body in a second direction around the pair of protruded portions formed on opposite faces thereof at a position remote from the line of engaging contacts between the cam tooth means and the lead screw.