Paper hold down and penetration control construction for high speed printers

Claim 2

In a high speed printer, first and second feed means each having projecting pins adapted to engage holes formed along the opposite edges of a record sheet and drivable to move the pins in a closed path to advance the record sheet in a longitudinal feeding direction; means mounting said first sheet feed means in a fixed position laterally of the feeding direction; adjustable means mounting said second sheet feed means for adjustment of the lateral spacing thereof from said first sheet feed means to accommodate record sheets of various widths; first and second sheet hold down plates constructed and arranged for cooperation with said first and second sheet feed means, respectively, to prevent sheet engaged with said pins from escaping; means mounting said first hold down plate in fixed lateral relation to said first sheet feed means; means mounting said second hold down plate for movement laterally of the feeding direction; said second sheet feed means and said second hold down means being provided with cooperating cam means for automatically aligning said second hold down means with said second sheet feed means in adjusted positions thereof laterally of the feeding direction.

Claim 3

A high speed printer as recited in claim 1 including a main frame mounting said sheet feed means and said mounting means therefor, and a yoke pivotally mounted on said frame and bearing said hold down plates and said mounting means therefor, said yoke means being pivotal about an axis extending laterally of the feeding direction of said record sheet for movement between a first position operatively relating said hold down plates with said sheet feed means, and a second position separating said hold down plates from said sheet feed means; said cam means being engageable by pivotal movement of said yoke means from said second to said first position for automatically aligning said second hold down plate with said second sheet feed means as said yoke means is moved toward said first position.

Claim 4

A high speed printer as recited in claim 2, in which said second hold down plate is slidably mounted on said yoke means for movement laterally of the sheet feeding direction, said second hold down plate being formed with a guide lip forming a first portion of said cam means; said second sheet feed means being provided with a second portion of said cam means having a laterally enlarged slot for accepting said guide lip in positions of said second hold down plate laterally misaligned from said second feed means, said slot being formed to guide said lip into a position aligning said second hold down plate with said second feed means as said yoke means is pivoted into said first position.

Claim 5

A high speed printer as recited in claim 2, together with an adjustable penetration control comprising a first stop, means mounting said first stop on said frame, a second stop and means mounting said second stop on said yoke in position to engage said first stop in said first position of said yoke, one of said mounting means being adjustable to control the closest approach of said yoke means to said frame and thereby determine the gap between said hold down plates and tractors.

Claim 6

A high speed printer as recited in claim 4, together with a bank of print hammers mounted on said main frame, a print drum rotatably mounted in said yoke for coopeRation with said hammers in positions in the vicinity of said first position of said yoke means, said adjustable mounting means serving to adjust the force with which said hammers engage said print roll, simultaneously with adjustment of the gap between by said hold down plates and tractors.

Claim 7

In a high speed printer having a main frame in which a bank of print hammers is mounted, a pair of sheet feed tractors mounted on said frame on opposite sides of a path over said print hammers along which a sheet is to be fed for printing, said tractors comprising drive pins for engaging perforations formed along the opposite edges of the sheet, a yoke pivotally mounted on said frame for movement between first and second positions with respect to said frame, and a print drum rotatably mounted in said yoke for cooperation with said hammers in positions in the vicinity of said first position of said yoke; a pair of paper hold down plates, means mounting said plates in laterally spaced relation on said yoke each in position to prevent a sheet engaged by the pins on a different one of said tractors from escaping from said pins in positions adjacent said first position of said yoke; an adjustable penetration control comprising a first stop, means mounting said first stop on said frame, a second stop, and means mounting said second stop on said yoke in position to engage said first stop, one of said mounting means being adjustable to control the closest approach of said yoke to said frame and thereby determine the gap between the hold down plates and tractors and simultaneously adjust the force with which the hammers engage the print roll.

Claim 8

In a high speed printer having a main frame in which a bank of print hammers is mounted, a pair of sheet feed tractors mounted on said frame on opposite sides of a path over said print hammers along which a sheet is to be fed for printing, said tractors comprising drive pins for engaging perforations formed along the opposite edges of the sheet, a yoke pivotally mounted on said frame for movement between first and second positions with respect to said frame, and a print drum rotatably mounted in said yoke for cooperation with said hammers in positions in the vicinity of said first position of said yoke; a pair of paper hold down plates, means mounting said plates in laterally spaced relation on said yoke each in position to prevent a sheet engaged by the pins on a different one of said tractors from escaping from said pins in positions adjacent said first position of said yoke; an adjustable penetration control comprising a first stop, means mounting said first stop on said frame, a second stop, and means mounting said second stop on said yoke in position to engage said first stop, one of said mounting means being adjustable to control the closest approach of said yoke to said frame and thereby determine the gap between the hold down plates and tractors and simultaneously adjust the force with which the hammers engage the print roll.

Claim 9

A high speed printer as recited in claim 6, at least one of said hold down plates being mounted for movement laterally of said path, a corresponding one of said tractors being adjustable laterally of said path to accommodate sheets of various widths, said one hold down plate and said one tractor being provided with cooperating cam means for aligning said one hold down plate with said one tractor in adjusted positions of the latter.

Claim 10

A high speed printer as recited in claim 7, said cam means being engageable by pivotal movement by said yoke toward said first position thereof.

Claim 11

A high speed printer as recited in claim 8, said one hold down plate being formed with a guide lip forming a first portion of said cam means; said one tractor being provided with a second portion of said cam means having a laterally enlarged slot for accepting said guide lip in positions of said one hold down plate laterally misaligned from said one tractor in adjusted positions thereof, said slot being formed to guide said lip into a position aligning said one hold down plate with said one tractor as said yoke is pivoted into said first position.