GB770926A - Improvements in web guiding apparatus - Google Patents

Abstract

770,926. Automatic alignment control systems. ROBERTSON, J. D. Jan. 4,1955, No. 204/55. Class 38 (4). [Also in Group XVI] A web guiding apparatus comprises a roller disposed between a pair of guide rollers, means supporting the roller for movements generally transverse to the direction of web travel and for tilting movement in a plane generally parallel with the common plane of the guide roll axes, mechanism for effecting such movements, and a detector actuated when the web is displaced laterally out of its correct lateral path to cause the mechanism to effect movement of the roller to return the web quickly into its correct lateral path. As shown, a web 10, Fig. 2, passes under fixed guide rollers 14, 18 and over a movable guide roller 16 carried by arms 201, 20<SP>2</SP> of a frame'20 mounted on a shaft 22 rotatable through pinions 28, 30 by a reversible electric motor 32, a feeler 24, Fig. 3, is pivotally mounted on a shaft 36, such that it is urged into engagement with the selvedge of the web 10 by a spring 38. Lateral deviation of the web 10 causes the feeler 24 to engage fixed contacts 40 or 42. A three-phase motor circuit 44 includes normally open switches 46, 48 which are closed by solenoids 50, 52 respectively. Solenoid 50 is energized when the feeler 24 engages the contact 40 and the solenoid 52 is energized when the feeler 24 engages the contact 42. A contact 56 is loose on the shaft of motor 32, such that, by friction, the contact 56 is rotated towards fixed contacts 55 or 60. When the web 10 deviates to the right contact 42 energizes solenoid 52 to close the switch 48 to rotate the motor 32 and contact 56 clockwise. Engagement of contacts 56, 58 conditions the solenoid 50 for energization. When the switch 48 opens, the motor 32 is driven counterclockwise to disengage the contacts 56, 58 to de-energize the solenoid 50 and motor 32. While the motor is energized the arms 201, 20<SP>2</SP>, Fig. 2, are rotated to move the web 10 laterally into its correct path. In a modification, two similar rollers 16 are employed. In a further modification, the roller 16 is supported by pivoted links 62, Fig. 4A, such that movement of the links simultaneously moves the roller 16 laterally of the web 10 and tilts the roller in the plane of the web. The links 62 are actuated by a piston-rod 84 slidable with a piston 82 in a cylinder 78 supplied with fluid under pressure through conduits 86 or 88 depending on the position of a slide valve 90. The valve 90 is normally in the position shown, but may be actuated upwardly or downwardly against springs 94 by solenoids 108 or 110 energized upon deviation of the web as detected by the feeler 24. When in its upper position fluid is supplied through conduit 96, branch 961, passage 98, and conduit 86 to the cylinder 78, while the conduit 88 exhausts through a port 102 and conduit 106. The cylinder 78 is similarly supplied with fluid to its lower end when the valve is in its lower position. The cylinder links 62 may alternatively be actuated through 'worm gearing, by an electric motor controlled by deviation of the web. In a further modification, the roller 16 is curved and is pivotally mounted on a transversely slidable carriage 126, Figs. 5 and 6 (not shown), actuated by fluid pressure in the same manner as the cylinder 78, Fig. 4A. The roller is also caused to tilt in the plane of the web by cam surfaces engaged by rollers on a frame supporting the roller while an electric motor controlled by a web-engaging feeler rotates the roller 16 about its own axis to effect stretching of the web.