Automated cut-to-mark control for cut-off machine

A method of automatically controlling at least first and second cut-off machines each having knives operable in a cut-to-mark mode wherein the knives cut a moving web divisible into a leader having a first set of registration marks and trailer having a second second of registration marks, there being a transition between the first and second sets of marks, comprising:

• (a) applying a target to the trailer adjacent a preselected registration mark of the second set;
• (b) tracking the target electronically to a shear upstream of the cut-off machines;
• (c) automatically severing the web transversely at the shear into a leader and trailer when the target is tracked to the shear;
• (d) directing the leader to said first cut-off machine;
• (e) causing the knives of said first cut-off machine to cut the leader in the cut-to-mark mode at the registration marks of the first set;
• (f) tracking the target electronically from said shear to a position intermediate the shear and said cut-off machines;
• (g) directing the trailer to said second cut-off machine;
• (h) causing the knives of said second cut-off machine to cut the trailer automatically at the preselected registration mark of the second set;
• and
• (i) causing the knives of said second cut-off machine to cut the trailer automatically in the cut-to-mark mode at the registration marks of the second set which follow said preselected registration mark.

Apparatus for automatically controlling a cut-off machine having knives operable in a cut-to-mark mode wherein the knives cut a moving web divisible into a leader having a first set of registration marks and trailer having a second set of registration marks, there being a transition between the first and second sets of marks, said trailer being provided with a target adjacent a preselected registration mark of the second set, comprising:

• (a) a shear upstream of said cut-off machine for severing the web transversely into a leader and trailer;
• (b) means for tracking said target electronically to said shear and for causing said shear to sever the web into said leader and trailer when said target is tracked to said shear;
• (c) means for tracking the target electronically from said shear to a position intermediate the shear and said cut-off machine;
• and
• (d) means for causing said knives to repetitively cut the trailer at said second set of registration marks in the cut-to-mark mode beginning at the position of said preselected registration mark.

Apparatus for automatically controlling at least first and second cut-off machines each having knives operable in a cut-to-mark mode wherein the knives cut a moving web divisible into a leader having a first set of registration marks and a trailer having a second set of registration marks, there being a transition between the first and second sets of marks, said trailer being provided with a target adjacent a preselected registration mark of the second set, comprising:

• (a) a shear upstream of said cut-off machine for severing the web transversely into a leader and trailer;
• (b) means for tracking said target electronically to said shear and for causing said shear to automatically sever the web transversely into said leader and trailer when said target is tracked to said shear;
• (c) means for directing the leader to said first cut-off machine;
• (d) means for causing the knives of said first cut-off machine to cut the leader in the cut-to-mark mode at the registration marks of the first set;
• (e) means for tracking the target from said shear to a position intermediate the shear and said cut-off machines;
• (f) means for directing the trailer to said second cut-off machine;
• and
• (g) means for causing the knives of said second cut-off machine to repetitively cut the trailer at said second set of registration marks in the cut-to-mark mode beginning at the position of said preselected registration mark.