Process for imprinting spaced-apart web sections with a composite pattern

A process for printing a recurrent composite pattern on equispaced sections of a textile web separated by zones to be left unprinted, said sections being of identical length, comprising the steps of:

• a. passing the web to be imprinted underneath a plurality of parallel rotary printing units spaced apart in the direction of web motion while rotating said printing units in unison about respective axes at a speed commensurate with the web speed, each printing unit including a cylindrically curved screen centered on the respective axis with an arc length equal to the length of a section for the printing of a respective pattern component;
• b. detecting the arrival of a leading edge of any of said sections at a fixed point upstream of the first printing unit;
• c. detecting the passage of a predetermined point on the periphery of said first printing unit through a certain angular position;
• d. angularly adjusting all said printing units, in accordance with the relative time position of the events detected in steps (b) and (c), sequentially and with intervening delays corresponding to the travel time of said section from one printing unit to the next;
• and
• e. storing a measure of the angular adjustment according to step (d) in a memory decoupled from said first printing unit preparatorily to adjustment of each subsequent printing unit, thereby enabling readjustment of said first printing unit upon the approach of each new section.

A process for printing a recurrent composite pattern on equispaced tufted areas of a textile web separated by untufted zones to be left unprinted, said areas being of identical length, comprising the steps of:

• a. passing the web to be imprinted underneath a plurality of parallel rotary printing units spaced apart in the direction of web motion while rotating said printing units in unison about respective axes at a speed commensurate with the web speed, each printing unit including a cylindrically curved screen centered on the respective axis with an arc length equal to the length of a tufted area for the printing of a respective pattern component;
• b. detecting the arrival of a leading edge of any tufted area at a fixed point, upstream of the first printing unit, by sensing the tufts of any of said areas at said fixed point with a first and a second pointed implement disposed alongside each other and loaded with a first and a second pressure, respectively, said first pressure exceeding said second pressure whereby the arrival of said leading edge is indicated by an elevation of the second but not the first implement above the web surface;
• c. detecting the passage of a predetermined point on the periphery of said first printing unit through a certain angular position;
• and
• d. angularly adjusting all said printing units, in accordance with the relative time position of the events detected in steps (b) and (c).