Margin control structure

Claim 1

In a character-by-character printer, a margin control assembly comprising: a. a longitudinal margin stop rack supported for separately controlled and initiated limited independent rotational and longitudinal motion about and along, respectively, the longitudinal axis of said margin stop rack; b. first and second bias means for retaining said margin stop rack at first limits of its limited rotational and longitudinal motions, respectively, during character printing; c. first and second margin stop members selectively positionable on said margin stop rack for controlling and influencing the left- and right-hand margins, respectively; d. carrier means, including character printing means, mounted for letter escapement motion parallel and relative to said margin stop rack; e. controlled bidirectional drive means for selectively urging said carrier means in a letter space direction, and a return direction, wherein: i. said letter space direction is towards said second margin stop member; and ii. said return direction is towards said first margin stop member; f. projecting means on said carrier means for engaging said second margin stop member when said carrier means has been escaped to a position wherein said projecting means and said second margin stop member become engaged; g. first signal generating means for providing a first signal indicative of conditioning for carrier return in response to the pivotal motion of said margin stop rack away from its said first limit of rotation in consequence of the engagement of said projecting means and said second margin stop member; h. second signal generating means for providing a second signal in response to an escapement action of said carrier means when there is no character printing; i. said controlled bidirectional drive means being responsive to the generation of said second signal after the generation of said first signal for driving said carrier means in said return direction; j. engaging means on said carrier means for engaging said first margin stop member when said drive means drives said carrier means sufficiently far towards said first margin stop member; k. said engaging means and said first margin stop member coacting to longitudinally move said margin stop rack away from its said first limit of longitudinal motion in response to the engagement of said engaging means and said first margin stop member; and l. control means responsive to said longitudinal motion of said margin stop rack for terminating the driving of said carrier means in said return direction.