Systems and methods for folding a stack of substrate sheets

A system for folding substrate sheets comprising:

• a roller assembly configured to fold a stack of substrate sheets, the roller assembly including a first set of opposing rollers and a second set of opposing rollers juxtaposed with the first set of opposing rollers, the first and second sets of opposing rollers being configured and arranged to rotate to draw at least a portion of the stack of substrate sheets through the first and second sets of opposing rollers, the roller assembly further including a third set of opposing rollers downstream from the second set of opposing rollers;
• and
• a positioning mechanism configured to position the stack of substrate sheets for entry into the roller assembly, the positioning mechanism including an upper curved form and a lower curved form to guide the stack of substrate sheets into a curved position for folding, the upper and lower curved forms forming an elongated aperture therebetween, the positioning mechanism further including a folding blade slidably positioned to extend through the elongated aperture between the upper and lower curved forms to push the stack of substrate sheets in the curved position toward the roller assembly,
• wherein the upper curved form includes a first flange adjacent the aperture and extending downwardly and toward the roller assembly,
• wherein the lower curved form includes a second flange adjacent the aperture and extending upwardly and toward the roller assembly,
• wherein a controller is programmed to rotate the second and third sets of rollers to draw at least the folded portion of the stack through the second and third sets of opposing rollers, and
• wherein the second and third sets of opposing rollers are configured and arranged to reverse direction of rotation to draw at least the folded portion of the stack of substrate sheets back through the third set of opposing rollers, and thereafter to reverse the direction of rotation to drive the folded portion of the stack between the third set of opposing rollers.

A system for folding substrate sheets comprising:

• a roller assembly configured to fold a stack of substrate sheets;
• and
• a positioning mechanism configured to position the substrate for entry into the roller assembly, the positioning mechanism including an upper curved form and a lower curved form to guide the stack of substrate sheets into a curved position for folding, the upper and lower curved forms forming an elongated aperture therebetween, the positioning mechanism further including a folding blade slidably positioned to extend through the elongated aperture between the upper and lower curved forms to push the stack of substrate sheets in the curved position toward the roller assembly and a clamping mechanism proximate one of the upper and lower curved forms to secure the stack of substrate sheets to a portion of a concave surface of the upper and lower curved forms,
• wherein the upper curved form includes a first flange adjacent the aperture and extending downwardly and toward the roller assembly, and wherein the lower curved form includes a second flange adjacent the aperture and extending upwardly and toward the roller assembly,
• wherein the clamping mechanism is configured to release the stack of substrate sheets after the folding blade extends through the elongated aperture.

A method for folding a stack of substrate sheets comprising:

• feeding a stack of substrate sheets into a form;
• pressing the stack of substrate sheets through a gap in the form to form a folded end of the stack;
• receiving the stack of substrate sheets between a first set of opposing rollers with the folded end being initially received by the first set of opposing rollers;
• moving the folded end of the stack of substrate sheets in a first direction between the first set of opposing rollers from a receive side to an exit side;
• receiving the folded end of the stack of substrate sheets between a second set of opposing rollers from a receive side;
• moving the stack of substrate sheets in the first direction so that the folded end moves past the second set of opposing rollers with at least a part of the stack of substrate sheets remaining in the first set of opposing rollers;
• after moving the stack of substrate sheets, stopping the first and second set of opposing rollers with the folded end being downstream and free of the second set of opposing rollers;
• reversing direction of the stack of substrate sheets to a second direction by reversing rotation of the first and second set of opposing rollers so that the folded end moves past the receive side of the second set of opposing rollers with at least a part of the stack of substrate sheets remaining in the first set of opposing rollers;
• moving the stack of substrate sheets in the first direction so that the folded end moves past the second set of opposing rollers;
• and
• further moving the stack of substrate sheets in the first direction so that the free end moves past the first set of opposing rollers.

A method for folding a stack of substrate sheets comprising:

• positioning a stack of non-continuous substrate sheets for folding from an aperture in a curved form;
• feeding the stack of substrate sheets into a first set of rollers by driving an approximate midpoint section of the stack toward a contact point of the first set of rollers;
• driving the first set of rollers to receive the approximate midpoint section of the stack of substrate sheets from the feeding at a first side of the first set of rollers and passing the stack of substrate sheets to a second set of rollers in a horizontal, first direction to fold the stack of substrate sheets at the approximate midpoint section to form a closed end of the folded stack of substrate sheets and an open end of the folded stack of substrate sheets;
• receiving the folded approximate midpoint section of the stack of substrate sheets from rolling the first set of rollers at a first side of the second set of rollers;
• driving the first and second sets of rollers to reverse the stack of substrate sheets from the first direction to travel in a horizontal, second direction such that the open end of the stack of substrate sheets is received at a second side of the first set of rollers and the folded approximate midpoint section passing from the second set of rollers;
• driving the first and second sets of rollers to reverse the stack of substrate sheets from the second direction to the first direction with the first set of rollers having the stack of substrate sheets therebetween to cause the stack of substrate sheets to travel again in the first direction;
• and
• after the first and second sets of rollers reverse the stack of substrate sheets from the second direction to the first direction, again receiving the folded approximate midpoint section at a contact point of the second set of rollers and passing the stack of substrate sheets to a second side of the second set of rollers.