Paper feed mechanism for data printers

Claim 2

In a data printer having a printing station, printing means adjacent said station, cyclically operable drive means for said printing means, and means forming a channel for guiding a strip of paper past said station in either of opposite directions, said paper being of such flexibility that it will buckle against the sides of said channel when said paper is pushed endwise in said channel; the combination comprising retracting means operable prior to operation of said printing means for pulling said paper endwise in one direction in said channel a first predetermined amount whereby to present a print line to said printing means, advancing means operable after operation of said retracting means and prior to operation of said printing means for pushing said paper endwise in the other of said directions in said channel an amount sufficient to cause said paper to buckle against the sides of said channel, and advancing means operable after operation of said printing means for further pushing said paper a second predetermined amount whereby to line space said paper relative to said printing means.

Claim 3

The combination according to claim 1 comprising means for selectively causing said retracting means to pull said paper different amounts.

Claim 4

The combination according to claim 1 wherein said retracting means is yieldable, comprising means for selectively arresting said retracting means when said retracting means has pulled said paper an amount less than said first predetermined amount.

Claim 5

The combination according to claim 1 wherein said channel has an entrance remote from said station and wherein said advancing means and said retracting means include a common paper feed roller adjacent the entrance of said channel and drivingly engageable with the paper.

Claim 6

In a data printer having a printing station, printing means adjacent said station, cyclically operable drive means for said printing means, and means forming a channel for guiding a strip of paper past said printing station; said paper being of such flexibility that it will buckle against the sides of said channel when said paper is pushed endwise in said channel; the combination comprising feeding means for said paper including a roller adjacent said channel; yieldable means operable prior to operation of said printing means for normally rotating said roller a predetermined amount in one direction to pull said paper in said channel, means operable after operation of said last mentioned means and prior to operation of said printing means for rotating said roller an amount less than said predetermined amount in the opposite direction to push said paper in said paper in said channel an amount to cause said paper to buckle against the sides of said channel, means operable after operation of said printing means for rotating said roller in said opposite direction to push said paper a second predetermined amount whereby to line space said paper, and selectively operable means to arrest said yieldable means when said paper is retracted an amount less than said first mentioned predetermined amount.

Claim 7

In a data printer having a printing station, printing means adjacent said station, cyclically operable drive means for said printing means, and means forming a channel for guiding a strip of paper past said printing station; said paper being of such flexibility that it will buckle against the sides of said channel when said paper is pushed endwise in said channel; the combination comprising feeding means for said paper including a roller adjacent said channel; yieldable means operable prior to operation of said printing means for normally rotating said roller a predetermined amount in one direction to pull said paper in said channel, means operable after operation of said last mentioned means and prior to operation of said printing means for rotating said roller an amount less than said predetermined amount in the opposite direction to push said paper in said paper in said channel an amount to cause said paper to buckle against the sides of said channel, means operable after operation of said printing means for rotating said roller in said opposite direction to push said paper a second predetermined amount whereby to line space said paper, and selectively operable means to arrest said yieldable means when said paper is retracted an amount less than said first mentioned predetermined amount.

Claim 8

In a data printer having a printing station, printing means adjacent said station, cyclically operable drive means for said printing means, and means forming a channel for guiding a strip of paper past said station from one printing line to another, said paper being of such flexibility that it will buckle against the sides of said channel when said paper is pushed endwise in said channel, the combination comprising retracting means operable by said drive meAns prior to said operation of said printing means for pulling said paper in said channel an amount equal to one line space plus a fraction of said line space, advancing means operable by said drive means after operation of said retracting means for pushing said paper in said channel an amount equal to said fraction whereby to cause said paper to buckle against the sides of said channel, and advancing means operable after operation of said printing means for pushing said paper an amount equal to a multiple of said line space.

Claim 9

In a data printer having a printing station, printing means adjacent said station, cyclically operable drive means for said printing means, and means forming a channel for guiding a strip of paper past said station from one printing line to another, said paper being of such flexibility that it will buckle against the sides of said channel when said paper is pushed endwise in said channel, the combination comprising retracting means operable by said drive meAns prior to said operation of said printing means for pulling said paper in said channel an amount equal to one line space plus a fraction of said line space, advancing means operable by said drive means after operation of said retracting means for pushing said paper in said channel an amount equal to said fraction whereby to cause said paper to buckle against the sides of said channel, and advancing means operable after operation of said printing means for pushing said paper an amount equal to a multiple of said line space.

Claim 10

The combination according to claim 6 comprising means for selectively causing said retracting means to pull said paper an amount equal to said fraction of said line space only.

Claim 11

In a data printer having a printing station, printing means adjacent said station, cyclically operable drive means for said printing means and means forming a channel for guiding a strip of paper past said printing station, said paper being of such flexibility that it will buckle against the sides of said channel when said paper is pushed endwise in said channel, the combination comprising a paper feed roller adjacent said channel and engageable with said paper, said feed roller being rotatable in a direction to pull said paper relative to said printing means and rotatable in an opposite direction to push said paper relative to said printing means, first gear means operable by said drive means prior to operation of said printing means for rotating said feed roller in said paper pulling direction, second gear means operable by said drive means after operation of said first gear means and prior to operation of said printing means for rotating said feed roller in said paper pushing direction whereby to cause said paper to buckle against the sides of said channel, said second gear means being operable by said drive means after said printing operation for further rotating said feed roller in said paper pushing direction whereby to line space said paper.

Claim 12

In a data printer having a printing station, printing means adjacent said station, cyclically operable drive means for said printing means and means forming a channel for guiding a strip of paper past said printing station, said paper being of such flexibility that it will buckle against the sides of said channel when said paper is pushed endwise in said channel, the combination comprising a paper feed roller adjacent said channel and engageable with said paper, said feed roller being rotatable in a direction to pull said paper relative to said printing means and rotatable in an opposite direction to push said paper relative to said printing means, first gear means operable by said drive means prior to operation of said printing means for rotating said feed roller in said paper pulling direction, second gear means operable by said drive means after operation of said first gear means and prior to operation of said printing means for rotating said feed roller in said paper pushing direction whereby to cause said paper to buckle against the sides of said channel, said second gear means being operable by said drive means after said printing operation for further rotating said feed roller in said paper pushing direction whereby to line space said paper.

Claim 13

The combination according to claim 8 wherein said first and second gear means comprise interrupted gear teeth whereby to incrementally move said paper.

Claim 14

The combination according to claim 8 comprising means for selectively varying the extent of rotation of said feed roller by said first gear means.