Printing mechanism with movable type wheel and hammer carriages

Claim 1

A high speed printing arrangement for serially recording selected characters along the print line of a recording medium in response to input signal code combinations comprising: a. a movable type wheel carriage assembly positioned to one side of the recording medium, said type wheel carriage assembly including a continuously rotating type wheel having the character types arranged circumferentially thereon and having on a flat surface thereof a revolution indicating projection and a plurality of type position indicating projections, means for rotating said type wheel adjacent to the recording medium, and adjustable sensing means, which include a compound inductor unit having a set of letter E laminations with a permanent magnet secured to the center limb and individual coils on each of the outer limbs, and positioned proximate to said flat surface and stationarily arranged with respect to the rotation of said type wheel, said adjustable sensing means being arranged to generate a pulse each time either a type indicating projection or the revolution indicating projection passes relative thereto, said sensing means having an adjustment for altering the timing of projection sensing by changing the relative position of said sensing means with respect to the type wheel projections; b. a movable hammer carriage assembly positioned on the other side of the recording medium, said hammer carriage assembly including hammer means responsive to an activation signal for impacting a selected type on said type wheel with the recording medium; c. means for supporting and moving said carriage assemblieS simultaneously along a path parallel to the print line and spacing the travel thereof in accordance with the character spacing along the print line; and d. function control circuitry, responsive to the pulses generated by said adjustable sensing means and to said input coded signals, for controlling the movement of said carriage assemblies along the print line and for controlling the motion of said hammer means via said activation signal to effect the printing of a selected character on the recording medium.