GB1379481A - Apparatus for opening and uncurling sheet or web material - Google Patents

Abstract

1379481 Uncurling webs MOUNT HOPE MACHINERY Ltd 6 Jan 1972 [7 Jan 1971] 622/72 Heading B8R Web selvedge uncurling apparatus is formed by two pairs of rotary uncurlers 14 and 54, 56, Fig. 1, disposed adjacent opposite selvedges and behind each other, respectively, and associated with a control means formed by pneumatic sensing heads 49 which senses the disposition of the selvedges with respect to a predetermined path of web movement to actuate diagonally disposed uncurlers 14, 54, 56 so as to drive the uncurler 14 at a higher speed and disengage the uncurler 54 from the web when a selvedge associated with the uncurler 14 has moved laterally inwardly of the web path, the speed of the disc uncurler being restored to the normal, lower speed following correction of lateral movement. The uncurlers 14 are formed by pairs of rotary discs disposed at an angle to each other and provided with interengaging pawls 16 which grip the selvedge and pull it laterally outwardly. The lateral pull past the sensing heads 49 is maintained by uncurlers 54, 56 formed by helically grooved frusto-conical rollers, one of which 56 is mounted in a pivoted arm 55 actuated by a fluid cylinder to bring the roller 56 into and out of contact with the selvedge depending on the fluid signal produced by the associated sensing head. The sensing heads 49 are each provided with pairs of opposed jets and receivers 78, 82; 80, 84, Fig. 3, the jets being supplied with compressed air via lines 76, 72 and pressure regulators 68 from a source which also supplies compressed air via a common line 102 and a further regulator 104 to drive the disc uncurlers 14 and pivot the arms 55 of uncurlers 54. During normal operation the disc uncurlers 14 are driven at a lower speed by compressed air supplied at a lower pressure through pipes 118, 120 provided with pressure regulators 110, 112, respectively, the uncurlers 54, 56 being driven by the moving web by virtue of contact therewith. On lateral inward displacement of the web with respect to the left disc uncurler 14 the jet 78 which was obturated by the web selvedge during normal operation, enters the receiver 82 to increase the pressure therein and produce a fluid signal which is applied to booster valve 98 via a line 94 to open the booster valve and supply compressed air at a higher pressure via a line 122 and a check valve 114 to the left disc uncurler 14 to rotate at a faster speed to correct the displacement which correction is assisted by pivoting the right hand uncurler 54 away from its associated selvedge in consequence of actuation by a piston 64 to which the higher pressure admitted by the booster valve 98 is supplied simultaneously via a line 134. On restoration of the web selvedge displacement the receiver 82 is again obturated, the booster valve 98 closed and the speed left disc uncurler 14 reduced, whilst the uncurler 54 is pivoted back into selvedge contact. On lateral outward selvedge displacement with respect to the left disc uncurler, the right hand selvedge receiver 82 becomes active to correct the displacement.