Electromagnetic line spacing device

摘要

A platen for a typewriter, is rotated intermittently by pulsing a winding to establish flux between poles of a stator and a rotor, which rotates through a fixed angle and then back to a datum position under the action of a spring. The magnetic flux also engages an electro magnetic clutch formed by the rotor and a part rotationally fast with the platen so that the platen is rotated only during the forward rotation of the rotor. The stator, rotor and said part are all coaxial with the platen and may be housed inside the platen.