Printing apparatus employing bidirectional stepping motors to position type member

Abstract

A printer is disclosed that utilizes a single font of somewhat cylindrical configuration, bearing type for various symbols upon its peripheral surface. The font is movably mounted to accommodate rotation and axial displacement, to set a desired symbol in printing position. The type font is controlled in movement by shift registers operating in combination with a source of pulses bi-directional stepping motors and reset apparatus. The printer is responsive to various codes which are registered by components in the shift registers which are then cleared by pulses that step the stepping motors to position the type font by driving the stepping motors in a forward direction to accomplish the desired position in components. Thereafter, the type font is actuated to print the desired symbol. Structure is disclosed for returning the type font to a home position by reverse stepping the stepping motors.

What is claimed is:  .[. 
     
       1.  A printer for executing various symbols on command, comprising: a type element with plural symbols carried thereon;   mounting means for said type element, whereby said element may be variously displaced to present said symbols thereon in a printing position;   means for providing a series of electrical pulses indicative of a desired displacement of said type element to accomplish a predetermined symbol;   at least one bidirectional stepping motor having a home position and connected to receive said pulses for displacing said type element in accordance with said electrical pulses;   means for activating said type element to print; and   means for returning said stepping motor for said home position after said type element is activated, by applying pulses to said stepping motor..].   
     
     
       2. A printer for a plurality of characters, comprising: a type body having lines defining said characters about the surface thereof;   means for supporting said type body whereby said type body may be variously displaced in plural directions from a quiescent position whereby to present said characters in a printing position;   means for providing plural sets of electrical pulses, each of said sets being indicative of a displacement in one direction to accomplish a desired position for a predetermined character;   a plurality of bidirectional stepping motors, each connected to receive one of said sets of electrical pulses and being mechanically coupled to said type body whereby to displace said type body in one direction;   means for activating said type body to print; and   means for providing return pulses to said stepping motors after said type body is activated to print.   
     
     
       3. A printer for printing any of a plurality of characters in sequence on a printing medium, comprising: a type body having lines defining said characters about the surface thereof;   support means for supporting said printing medium contiguous said type body;   mounting means for said type body whereby said body may be variously displaced to move each of said characters along at least two paths to position a select character in printing relationship to said medium;   means for providing at least two sets of electrical pulses, each indicative of a predetermined displacement of a select character along one of said paths to position said select character for printing;   at least two bidirectional stepping motors, each connected to receive one of said sets of electrical pulses, said stepping motors being connected to said type body whereby to displace each of said characters along one of said paths in accordance with said sets of electrical pulses; and   means to activate said type body relative said printing medium, whereby to print.   
     
     
       4. A printer for printing any of a plurality of characters in sequence on a printing medium, in accordance with electrical code signals indicative of characters comprising: a type body having lines defining said characters about the surface thereof;   support means for supporting said printing medium contiguous said type body;   mounting means for said type body whereby said body may be variously displaced to move each of said characters along at least two directional paths to position a select character in printing relationship to said medium;   plural shift registers for receiving components of said electrical code signals indicative of characters;   means for pulsing said shift registers to provide sets of pulses, each indicative of a displacement in one direction to accomplish a desired position for a predetermined character;   a plurality of bidirectional stepping motors, each connected to receive one of said sets of electrical pulses and being mechanically coupled to said type body whereby to each displace said type body in one of said directions; and   means to activate said type body relative said printing medium, whereby to print.   
     
     
       5. A printer according to claim 4, wherein said type body is generally cylindrical and said mounting means enables displacement along and about the central axis of said generally-cylindrical type body, 
     
     
       6. A printer according to claim 5 wherein said means to activate said type body comprises a hammer means to drive said printing medium against said type body to impress a character on said medium. 
     
     
       7. A printer for printing any of a plurality of characters in sequence on a printing medium, in accordance with electrical code signals indicative of characters, comprising: a type body having lines defining said characters about the surface thereof;   means for supporting said printing medium continguous said type body;   mounting means for said type body whereby said body may be variously displaced to move each of said characters in two directions along at least two paths to position a select character in printing relationship to said medium;   plural shift registers for receiving components of said electrical code signals indicative of characters;   means for pulsing said shift registers to provide sets of pulses, each indicative of a displacement in one direction to accomplish a desired position for a predetermined character;   a plurality of bidirectional stepping motors, each connected to receive one of said sets of electrical pulses and being mechanically coupled to said type body whereby to displace said type body in one direction;   means to activate said type body relative said printing medium, whereby to print;   shift means to shift said type body relative said printing medium upon each printing operation whereby to provide a fresh section of said medium for said type body; and   means to supply return pulses to said stepping motors to displace said type body in the other directions to a reset position.   
     
     
       8. A printer according to claim 7 wherein said stepping motors include means to signal a home position thereof and wherein said system includes means for providing return step pulses to said stepping motors after each printing operation, terminated by said means to signal a home position. 
     
     
       9. A printer according to claim 7 wherein said shift registers are connected to register component parts of said electrical code signals and wherein said system further includes means to provide pulses to form said sets of pulses, and to clear said code signals for said shift registers whereby to define said sets of pulses.