GB1324325A - Self-centering crossfolder - Google Patents

Abstract

1324325 Folding sheets THOMAS BROADBENT & SONS Ltd 14 March 1972 [22 March 1971] 7526/71 Heading D1S A laundered sheet 12 fed in offset relation to a fold plane is folded by subjecting the sheet to first means 22 disposed above the sheet and in line with the fold plane to introduce part of the sheet 12 between a pair of squeeze rollers 14, 16 and into the fold plane, detecting the passage of the shorter side of the sheet 12 into the fold plane with a first detector 26 spaced a selected distance from the fold plane and clamping with a clamp 30. The sheet 12 in response to operation of the detector 26, continuing to feed the longer side of the sheet into the fold plane while detecting its passage with a second detector 28 spaced a selected distance from the fold plane, operation of the detector 28 releasing the shorter side of the sheet 12 to allow the complete passage of the sheet between the rollers 14, 16 in the fold plane so that the sheet is folded in a manner predetermined by the selected positioning of the detectors 26, 28 with reference to the fold plane. The roller 14 is mounted on an arm 18 pivoted at 20 so that the roller is movable into and out of the driving position. Folding is effected by an air blast pipe 22 adjacent to which is a traction blow pipe 24. The detectors 26, 28 may each comprise a photocell and light source or a feeler switch. As shown, the sheet 12 is fed along a conveyor 10 out of the plane of the paper and is offset to the left of the fold plane. The pipe 22 initially introduces the sheet between the rollers 14, 16 and when its right hand edge passes the detector 26 the clamp 30 holds the right hand section of the sheet stationary. The roller 14 is pivoted to its non- driving position, the pipe 22 is deactuated and the pipe 24 actuated. Air from the pipe 24 drives the left hand section of the sheet around the roller 16, Fig. 3. When the left hand edge of the sheet passes the detector 28, the clamp 30 is released, the pipe 24 deactuated, and the roller 14 returns to its driving position. The rollers 14, 16 complete the fold. In a modification (not shown), the pipe 24 is replaced by a roller pivotally mounted above the roller 16. If an additional fold is desired, a roller 32 may be provided beneath the roller 16 together with a blowpipe 34.