Structure of multipurpose sheet folding and stacking machine

Abstract

Folding and stacking machine ( 100 ) of a web of paper, or similar products includes a first sheet feeding line ( 201 ) and a second sheet feeding line ( 202 ). The machine ( 100 ) also includes a folding section ( 200 ) having a couple of folding rollers ( 7, 8 ) that work at a linear folding speed V P and are adapted to receive a plurality of sheets ( 11 ) of length L that are overlapped for a fraction Y of their length L and to fold them into a plurality of panels (P). The first and the second sheet feeding lines ( 201, 202 ) provide respective cutting sections of the sheets starting from webs of paper ( 10, 10′ ). These proceed respectively at a speed V 1 and V 2 with respect to the folding speed V P , where a first speed (V 1 ) has a ratio X 1 with respect to the folding speed V P , V 2 and a second speed V 2 second has a ratio X 2 with respect to the folding speed V P . The first and the second sheet feeding lines ( 201, 202 ) can be operated selectively and independently, i.e. separately from each other or at the same time, according to the desired type of interfolded configuration.

1 . Folding and stacking machine to obtain packages of folded sheets starting from a web of paper, or similar material, comprising:
 a folding section comprising a couple of folding rollers, said couple of folding rollers having a folding linear speed V P , said folding rollers receiving a plurality of sheets and folding said sheets into a plurality of panels;   feeding means for feeding said sheets to said folding rollers, said feeding means comprising a first and a second sheet feeding line that are separate from each other,   characterised in that:   said first sheet feeding line has a first sheet cutting section starting from a first web that works at a first feeding speed V 1 , wherein said first feeding speed V 1  has a ratio X 1  with respect to the folding speed V P ,   said second sheet feeding line has a second sheet cutting section starting from a second web that works at a second feeding speed V 2 , wherein said second feeding speed V 2  has a ratio X 2  with respect to the folding speed V P ,   means are provided for operating selectively and independently said first and said second sheet feeding lines.   
   
   
       2 . Machine according to  claim 1 , wherein said first cutting section of said first sheet feeding line comprises:
 first cutting and transfer means adapted to cut a first web of paper into first sheets of length L 1  and to transfer them along a transfer path;   actuating means for actuating said cutting and transfer means so that said first web of paper and said first sheets proceed at said first speed V 1 ;   
     and furthermore, said first sheet feeding line comprises:
 overlapping means adapted to pick up said sheets from said transfer path and to overlap them in turn for a predetermined sheet portion, said portion being a fraction Y 1  of said length L 1 ; 
 actuating means for actuating said overlapping means adapted to convey said first sheets at said speed V P  less than said first speed V 1  towards said folding section, said speed difference being achieved for overlapping partially two consecutive sheets according to said portion; 
 and the cutting section of said second sheet feeding line comprises: 
 second cutting and transfer means adapted to cut the second web of paper into second sheets of length L 2 =L 1  and to transfer them along a transfer path towards said folding section; 
 actuating means for actuating said second cutting and transfer means adapted to cause them to work at a speed V 2  with said ratio X 2  equal to 1, whereby V 2 =V P ; 
 a microprocessor unit being provided adapted to control said actuating means between a first and a second condition, such that: 
 in said first condition said actuating means for actuating said second line are kept still and said machine operates as multi-fold machine with sheets fed only through said first line; 
 in said second condition said actuating means for actuating said second line are operated so that said ratio X 1  is equal to 1, whereby V 1 =V P  and so that said first sheets and said second sheets arrive already shifted in a confluence between said first and second line, so that said machine has single-fold type operation. 
 
   
   
       3 . Machine according to  claim 1 , wherein said first cutting section of said first sheet feeding line comprises:
 first cutting and transfer means adapted to cut a first web of paper into first sheets of length L 1  and to transfer them along a transfer path;   actuating means for actuating said cutting and transfer means so that said first web of paper and said first sheets proceed at said first speed V 1 ;   
     and furthermore, said first sheet feeding line comprises:
 overlapping means adapted to pick up said sheets from said transfer path and to overlap them in turn for a predetermined sheet portion, said portion being a fraction Y 1  of said length L 1 ; 
 actuating means for actuating said overlapping means adapted to convey said first sheets at said speed V P  less than said first speed V 1  towards said folding section, said speed difference being achieved for overlapping partially two consecutive sheets according to said portion; 
 and the cutting section of said second sheet feeding line comprises: 
 second cutting and transfer means adapted to cut a first web of paper into first sheets of length L 2  and to transfer them along a transfer path; 
 actuating means for actuating said cutting and transfer means so that said first web of paper and said first sheets proceed at said first speed V 2 ; 
 
     and furthermore, said second sheet feeding line comprises:
 overlapping means adapted to pick up said sheets from said transfer path and to overlap them in turn for a predetermined sheet portion, said portion being a fraction Y 2  of said length L 2 ; 
 actuating means for actuating said overlapping means adapted to convey said first sheets at said speed V P  less than said first speed V 2  towards said folding section, said speed difference being achieved for overlapping partially two consecutive sheets according to said portion; 
 a microprocessor unit being provided adapted to control said actuating means between a first and a second condition, such that: 
 in said first condition said actuating means for actuating said second line are kept still and said machine operates as multi-fold machine with sheets fed to said folding section only through said first line obtaining a first folded and stacked product with folded sheets having a number of panels P 1 ; 
 in said second condition said actuating means for actuating said first line are kept still and said machine operates as multi-fold machine with sheets fed to said folding section only through said second line obtaining a second folded and stacked product with folded sheets having a number of panels P 2 . 
 
   
   
       4 . Machine according to  claim 1 , where in said first condition said first feeding speed V 1  has a ratio X 1  with respect to the folding speed V P  selected from the group comprised of:
 X 1 =3/2, for Z-type folded sheets with two interfolded panels;   X 1 =4/2, for W-type folded sheets with two interfolded panels;   X 1 =5/4 for five panel folded sheets with one interfolded panel;   X 1 =6/3, for six panel folded sheets with three interfolded panels;   X 1 =6/4 for six panel folded sheets with two interfolded panels;   whereas in said second condition said second feeding speed V 2  has a ratio X 2  with respect to the folding speed V P  selected from the group comprised of:   X 2 =3/2, for Z-type folded sheets with two interfolded panels;   X 2 =4/2, for W-type folded sheets with two interfolded panels;   X 2 =5/4 for five panel folded sheets with one interfolded panel;   X 2 =6/3, for six panel folded sheets with three interfolded panels;   X 2 =6/4 for six panel folded sheets with two interfolded panels;   
     being X 1  different from X 2 . 
   
   
       5 . Machine according to  claim 4 , where in said first condition said first feeding speed V 1  has a ratio X 1 =3/2 with respect to the folding speed V P  and in said second condition said second feeding speed V 2  has a ratio X 2 =4/2 with respect to the folding speed V P , such that when operating the first or second sheet feeding line it is possible to have with a single machine Z-type interfolded sheets or W-type interfolded sheets. 
   
   
       6 . Machine according to  claim 1 , wherein said folding and stacking machine has a folding section and two cutting sections, wherein a portion of said folding section is removable independently with respect to said cutting sections, said folding section comprising at least two folding rollers and being replaceable with an equivalent portion. 
   
   
       7 . Machine according to  claim 6 , wherein said folding section comprises two modules having each a mobile folding roller. 
   
   
       8 . Machine according to  claim 1 , wherein said folding and stacking machine has a folding section and two cutting sections, wherein a portion of said or each cutting section is removable independently with respect to the other cutting sections, said removable portion of said cutting section comprising at least one cutting roller and being replaceable with an equivalent portion. 
   
   
       9 . Machine according to  claim 8 , wherein a portion of the first cutting section that is adapted to operate at a speed V 1  with sheets of length L 1  is replaceable with an equivalent modular portion adapted to operate at a speed V 1 ′ with sheets of length L 1 ′. 
   
   
       10 . Machine according to  claim 8 , wherein a portion of the first cutting section that is adapted to operate at a speed V 2  with sheets of length L 2  is replaceable with an equivalent modular portion adapted to operate at a speed V 2 ′ with sheets of length L 2 ′. 
   
   
       11 . Machine according to  claim 6 , wherein said folding and stacking machine has a folding section and two cutting sections, each cutting section and said folding section having a removable portion that can be removed independently in order to change the length of the sheet, the panel length, the folding configuration. 
   
   
       12 . Machine according to  claim 8 , wherein said folding and stacking machine has a folding section and two cutting sections, each cutting section and said folding section having a removable portion that can be removed independently in order to change the length of the sheet, the panel length, the folding configuration. 
   
   
       13 . Machine according to  claim 1 , wherein for not interfolded folded products, said cutting sections are such that said speed V 1  or V 2  are identical or less than said speed V P .