Interfolder and Separator Arrangement and Methods of Separating a Stack of Sheets From a Continuously Building Stream of Sheets

Abstract

Methods and apparatuses for separating streams of interfolded sheets into individual stacks of sheets are provided. Separation of the stacks is provided by a plurality of fingers mounted to carriages that are moved into and out of openings the stream of interfolded sheets. The openings may be formed without using the force of gravity. Further, the fingers may be inserted into the openings with a motion that has a larger component in a direction parallel to the stream of interfolded sheets than in a direction perpendicular to the stream of interfolded sheets. Further, the components that separate the stacks also may transport the stacks and directly transfer the stacks to downstream components.

What is claimed is: 
     
         1 . A method of separating a stack of sheets from a continuous stream of interfolded sheets, the method including:
 supporting a continuously forming stream of interfolded sheets on a lower carriage;   inserting first, second, third and fourth count fingers into separate openings of the stream of interfolded sheets upstream of the lower carriage;   supporting a first upstream sheet forming a first bottom sheet of the continuous stream of interfolded sheets with the third count finger and controlling a first downstream sheet forming a top sheet of the stack with the second count finger;   increasing the spacing between the third and second count finger to separate the first upstream sheet from the first downstream sheet.   
     
     
         2 . The method of  claim 1 , further comprising supporting a second bottom sheet forming a bottom of the stack with the lower carriage and securing the stack of sheets between the lower carriage and the first count finger and second count finger such that the stack of sheets is controlled by the lower carriage and the first count finger and second count finger. 
     
     
         3 . The method of  claim 2 , further comprising transporting the stack of sheets to a downstream component under the control of the first count finger, second count finger and the lower carriage and directly transferring the stack of sheets to the downstream component from the control of the first count finger, second count finger and lower carriage 
     
     
         4 . The method of  claim 3 , wherein the downstream component is a conveyor and transporting the stack of sheets includes directly transferring the stack of sheets to the conveyor from the control of the first count finger, second count finger and the lower carriage. 
     
     
         5 . The method of  claim 3 , wherein directly transferring the stack of sheets to the downstream component includes retracting the lower carriage, first count finger and second count finger transversely from the path. 
     
     
         6 . The method of  claim 5 , wherein the retraction of the lower carriage, first count finger and second count finger is perpendicular to the path. 
     
     
         7 . The method of  claim 5 , further including, after transferring the stack of sheets to the downstream component, inserting the lower carriage into the opening in which the third count finger is located and then retracting the third and fourth count fingers to hand off the continuously forming stream of interfolded sheets to the lower carriage. 
     
     
         8 . The method of  claim 7 , further including separating a second stack of sheets from the stream of interfolded sheets including:
 inserting first, second, third and fourth count fingers into a second set of separate openings of the stream of interfolded sheets upstream of the lower carriage;   supporting a second upstream sheet forming a second bottom sheet of the continuous stream of interfolded sheets with the third count finger and controlling a second downstream sheet forming a top sheet of the second stack of sheets with the second count finger;   increasing the spacing between the third and second count finger to separate the second upstream sheet from the second downstream sheet.   
     
     
         9 . The method of  claim 1 , wherein:
 the separate openings include first, second, third and fourth openings, the first and second openings are adjacent one another and the third and fourth openings are adjacent one another; the second and third openings are separated from one another by a fifth opening.   
     
     
         10 . The method of  claim 1 , wherein:
 inserting first, second, third and fourth count fingers into separate openings of the stream of interfolded sheets upstream of the lower carriage includes:   inserting the first, second, third and fourth count fingers into four consecutive openings when adjacent sheets of the continuous stream of interfolded sheets have only a single panel interfolded; and   inserting the first and second count fingers into consecutive openings and inserting the third and fourth count fingers into consecutive openings and wherein the second and third count fingers are inserted into openings that are separated from one another by an opening other than the first and fourth openings when adjacent sheets of the continuous stream of interfolded sheets have more than one panel interfolded.   
     
     
         11 . The method of  claim 1 , wherein the count fingers are mounted to independently movable carriages. 
     
     
         12 . The method of  claim 1 , wherein none of the openings in the continuous stream of interfolded sheets in which components are inserted are formed by gravity. 
     
     
         13 . The method of  claim 1  further comprising switching the order of insertion of the first count finger and the second count finger such that the first count finger acts as the second count finger but from an opposite side of a center line of the continuous stream of interfolded sheets and switching the order of insertion for the third count finger and the fourth count finger such that the fourth count finger acts as the third count finger but from the opposite side of the center line and switching the order of insertion of the lower carriage and a sixth carriage such that the sixth carriage acts as the lower carriage but from the opposite side of the center line. 
     
     
         14 . The method of  claim 13 , wherein the first count finger, third count finger and lower carriages are located on a same first side of the center line and the second count finger, fourth count finger and sixth carriages are located on same second side of the center line being opposite the first side. 
     
     
         15 . An apparatus for forming stacks of interfolded sheets from a stream of sheets, the apparatus comprising:
 an interfolder arrangement for interfolding the stream of sheets into a continuous stream of interfolded sheets;   a separator arrangement including a lower carriage, first, second, third and fourth count fingers and a controller,   the lower carriage being downstream from the interfolder arrangement and selectively supporting the continuous stream of interfolded sheets exiting the interfolder arrangement;   the first, second, third and fourth count fingers being insertable into first, second, third and fourth openings of the continuous stream of interfolded sheets upstream of the lower carriage;   the controller being configured to control the motion of the lower carriage, and first, second, third and fourth count fingers into the continuous stream of interfolded sheets, the controller configured to:
 control the third count finger to be inserted into the third opening formed by a first upstream sheet forming a first bottom sheet of the continuous stream of interfolded sheets to support the first bottom sheet of the continuous stream of interfolded sheets upstream of the lower carriage; 
 control the second count finger to be inserted into the second opening formed by a first downstream sheet forming a top sheet of the stack to control a top of the stack upstream of the lower carriage; and 
 control the second count finger, third count finger and lower carriage to increase the spacing between the third and second count finger to separate the first upstream sheet from the first downstream sheet. 
   
     
     
         16 . The apparatus of  claim 15  wherein separator arrangement is configured to operate in a first count insertion sequence when adjacent sheets of the continuous stream of interfolded sheets have only a single panel interfolded and in a second count insertion sequence when adjacent sheets of the continuous stream of interfolded sheets have more than one panel interfolded;
 when operating in the first count insertion sequence, the controller controls the first, second, third and fourth count fingers to be inserted into the first, second, third and fourth openings such that the first, second, third and fourth count openings are consecutive openings; 
 when operating in the second count insertion sequence, the controller controls the first, second, third and fourth count fingers to be inserted into the first, second, third and fourth openings, respectively, with the first and second openings being adjacent one another, the third and fourth openings being adjacent one another and the second and third openings being separated from one another by an opening other than the first, second, third and fourth openings. 
 
     
     
         17 . The apparatus of  claim 15 , further including a downstream component downstream from the interfolder arrangement, the separator arrangement transporting the stacks of interfolded sheets to the downstream component with the stack being controlled between the lower carriage and the first and second count fingers such that the stacks of interfolded sheets are directly transferred from the lower carriage, first count finger and second count finger to the downstream component. 
     
     
         18 . The apparatus of  claim 17 , wherein the downstream component is a conveyor. 
     
     
         19 . The apparatus of  claim 15 , wherein the first count finger is mounted to a first carriage, the second count finger is mounted to a second carriage, the third count finger is mounted to a third carriage and the fourth count finger is mounted to a fourth carriage; further including a sixth carriage, the lower carriage, first, second, third, fourth and sixth carriages all being independently moveable. 
     
     
         20 . The apparatus of  claim 19 , wherein:
 the continuous stream of interfolded sheets defines a center line;   a first three of the first, second, third, fourth, sixth and lower carriages are located on a first side of the centerline; and   a second three of the first, second, third, fourth, sixth and lower carriages being located on a second side of the centerline.   
     
     
         21 . The apparatus of  claim 20 , wherein the first three includes the first carriage, the third carriage and the sixth carriage and the second three includes the second carriage the fourth carriage and the lower carriage. 
     
     
         22 . The apparatus of  claim 21 , wherein each of the first, second, third, fourth, sixth and lower carriages is movable parallel to the center line as well as into and out of the continuous stream of interfolded sheets. 
     
     
         23 . The apparatus of  claim 21 , wherein the controller is configured to switch the order of insertion for the first count finger and the second count finger such that the first count finger acts as the second count finger but from the opposite side of the center line and the controller is configured to switch the order of insertion for the third count finger and the fourth count finger such that the fourth count finger acts as the third count finger but from the opposite side of the center line and the controller is configured to switch the order of insertion of the lower carriage and the sixth carriage such that the sixth carriage acts as the lower carriage. 
     
     
         24 . A separating and interfolding apparatus comprising:
 a pair of counter rotating folding rolls rotating about axis of rotation;   at least one count finger pivoting between a retracted state and an extended state about a count finger axis of rotation, the count finger axis of rotation being positioned laterally outward from the axis of rotation of the folding rolls such that the count finger axis of rotation is not positioned between the folding roll axis of rotation.   
     
     
         25 . The separating and interfolding apparatus of  claim 24 , wherein a tip of the count finger moves in an axial direction parallel to a stream of interfolded sheets exiting the counter rotating folding rolls a further distance than the tip of the count finger moves horizontally perpendicular to the stream of interfolded sheets. 
     
     
         26 . The separating and interfolding apparatus of  claim 25 , wherein the axial motion is at least 30 percent greater than the horizontal motion. 
     
     
         27 . The separating and interfolding apparatus of  claim 25 , wherein the axial motion is at least 60 percent greater than the horizontal motion. 
     
     
         28 . A separator arrangement for separating stacks of interfolded sheets from a stream of interfolded sheets, the stream of interfolded sheets forming a center line, the separator arrangement comprising:
 a lower carriage, a first carriage, a second carriage, a third carriage, a fourth carriage, and a sixth carriage, the first, third and lower carriage being located on a first side of the center line, the second, fourth and sixth carriage being located on a second side of the center line opposite the first side;   a first count finger mounted to the first carriage, a second count finger mounted to the second carriage, a third count finger mounted to the third carriage and a fourth count finger mounted to the fourth carriage; and   a controller configured to control the first, second, third, fourth, sixth and lower carriages independently to insert the first, second, third, fourth count fingers, the lower carriage, and the sixth carriage into openings formed in the stream of interfolded sheets.   
     
     
         29 . The separator arrangement of  claim 24 , wherein the controller is configured to insert the first count finger, second count finger, third count finger, fourth count finger, lower carriage and sixth carriage into the stream of interfolded sheets based on a first count insertion sequence for a first interfolded product and based on a second count insertion sequence for a second interfolded product different than the first interfolded product. 
     
     
         30 . The separator arrangement of  claim 25 , wherein the controller is configured to operate in the first count insertion sequence when adjacent sheets of the continuous stream of interfolded sheets of the first product have only a single panel interfolded and in the second count insertion sequence when adjacent sheets of the continuous stream of interfolded sheets of the second product have more than one panel interfolded;
 when operating in the first count insertion sequence, the controller controls the first, second, third and fourth count fingers to be inserted into first, second, third and fourth openings that are consecutive openings;   when operating in the second count insertion sequence, the controller controls the first, second, third and fourth count fingers to be inserted into the first, second, third and fourth openings, respectively, with the first and second openings being adjacent one another, the third and fourth openings being adjacent one another and the second and third openings being separated from one another by an opening other than the first, second, third and fourth openings.   
     
     
         31 . The separator arrangement of  claim 24 , wherein the controller is configured to switch between first and second count insertion sequences, wherein switching between the first and second count insertion sequences switches the order of insertion for the first count finger and the second count finger such that the first count finger acts as the second count finger but from the opposite side of the center line;
 wherein switching between the first and second count insertion sequences switches the order of insertion for the third count finger and the fourth count finger such that the fourth count finger acts as the third count finger but from the opposite side of the center line; and   wherein switching between the first and second count insertion sequences switches the order of insertion of the lower carriage and the sixth carriage such that the sixth carriage acts as the lower carriage.