Paper folding machine

Claim 1

SHEET MATERIAL COLLATING APPARATUS COMPRISING MASTER SHEET MATERIAL FEED MEANS INCLUDING A FIRST PAIR OF OPPOSED COACTING ROLLERS, THE ROLLERS HAVING A COMMON TANGENTIAL PLANE, FOR FEEDING A MASTER SHEET IN THE DIRECTTION OF THE COMMON TANGENTIAL PLANE OF THE ROLLERS; A PAIR OF LATERALLY SPACED ABUTMENT SHOULDERS ON EITHER SIDE OF THE DIRECTION OF FEED OF THE MASTER SHEET, THE ABUTMENT SHOULDERS BEING PROVIDED BY A SECOND PAIR OF ROLLERS SPACED FROM THE FIRST PAIR AND HAVING ALSO A COMMON TANGENTIAL PLANE; DRIVE MEANS TO DRIVE THE ROLLERS IN CONTRAROTATING FASHION WHEREBY EACH PAIR OF ROLLERS WHEN ROTATING HAS A LEAD-IN REGION AND A LEAD-OUT REGION; SHEET FEED MEANS ADAPTED TO FEED A SHEET OF FOLDABLE MATERIAL TRANSVERSELY TO THE COMMON TANGENTIAL PLANES TO BOTH PAIRS OF ROLLERS AND BETWEEN THE LEAD-OUT REGION OF THE FIRST PAIR OF ROLLERS AND THE LEAD-IN REGION OF THE SECOND PAIR OF ROLLERS; THE ARRANGEMENT BEING SUCH THAT A MASTER SHEET OF PREDETERMINED MINIMUM STIFFNESS FED INTO THE LEAD-IN REGION OF THE FIRST PAIR OF ROLLERS WILL BE FED BY THE FIRST PAIR OF ROLLERS INTO THE LEAD-IN REGION OF THE SECOND PAIR OF ROLLERS AND IN TRAVELLING WILL BUCKLE A TRANSVERSELY DISPOSED SHEET OF FOLDABLE MATERIAL, FED BY THE SHEET FEED MEANS INTO THE LEAD-IN REGION OF THE SECOND PAIR OF ROLLERS THUS CAUSING THE FOLDABLE SHEET TO BE FOLDED OVER ONTO THE MASTER SHEET IN PASSING THROUGH BETWEEN THE SECOND PAIR OF ROLLERS; AN END-OF-SERIES PAIR OF ROLLERS HAVING DRIVE MEANS; AN END-OF-SERIES ROLLER IN ROLLING CONTACT WITH ONE OF THE ROLLERS OF THE END-OF-SERIES PAIR OF ROLLERS ON THE LEAD-OUT REGION AND HAVING A TRANSVERSE TANGENTIAL PLANE INTERSECTING THAT OF THE END-OF-SERIES PAIR OF ROLLERS AND DEFINING A SIDE LEAD-IN REGION AND A SIDE LEAD-OUT REGION DISPOSED TO ONE SIDE OF THE LEAD-OUT RE-