Marking apparatus

In printing apparatus having a printing head comprising a plurality of coaxial, rotatable printing wheels, disposed substantially side-by-side and employing printing characters, and a control rotor for controlling the printing wheels and having its axis parallel to that of said printing wheels and positioned to be moved bi-directionally to come into engagement with any selected printing wheel and then to be rotated about its axis to rotate the selected printing wheel for bringing into printing position a desired character thereon, the combination comprising:

• a) mounting means mounting said control rotor to
• i) move axially parallel to the axis of the printing wheels,
• ii) move toward and away from the axis of the printing wheels,
• iii) rotate as aforesaid
• b) and drive means to affect said i) movement, said ii) movement and said iii) rotation,
• c) said mounting means including a carriage for said control rotor, there being a frame mounting the carriage for movement axially parallel to the axis of the printing wheels, and said mounting means including a pusher on the carriage to push the control rotor toward a first position of engagement with the periphery of a printing wheel selected for rotation by the control rotor, and away from said selected wheel periphery to a second position free of engagement with said periphery to allow said control rotor movement parallel to the axis of the printing wheels,
• d) and including stop means on the carriage to block rotation of the control rotor when the control rotor is in said second position.

In printing apparatus having a printing head comprising a plurality of coaxial, rotatable printing wheels, disposed substantially side-by-side and employing printing characters, and a control rotor for controlling the printing wheel sand having its axis parallel to that of said printing wheel sand positioned to be moved bi-directionally to come into engagement with any selected printing wheel and then to be rotated about its axis to rotate the selected printing wheel for bringing into printing position a desired character thereon, there being a wire and printing media, the combination comprising:

• a) mounting means mounting said control rotor to
• i) move axially parallel to the axis of the printing wheels,
• ii) move linearly toward and away from the axis of the printing wheels,
• iii) rotate as aforesaid,
• b) and drive means to effect said i) movement, said ii) movement and said iii) rotation,
• c) said drive means that effects rotation of the control rotor including a first motor, and there being a first encoder means associated with said first motor for producing an encoding signal indicative of the rotary position of the control rotor,
• d) said drive means that effects said movement of the control rotor axially parallel to the axis of the printing wheels including a second motor, and there being a second encoder means associated with said second motor for producing an encoded signal indicative of the axial position of the control rotor relative to said printing wheels,
• e) and including means to feed said wire generally parallel to the axis of said printing wheels and into proximity to the peripheries of said printing wheels at which the printing characters are located, means to feed said printing media between said wire and said printing wheels, and clamping means operable to displace said wire relative to said printing wheels to clamp the printing media between the wire and selected characters on the printing wheels, thereby to print representations of said selected characters on the wire.