GB968370A - Improvements in and relating to web feeding devices - Google Patents

Abstract

968,370. Ink-ribbon mechanism. INTERNATIONAL BUSINESS MACHINES CORPORATION. Jan. 10, 1962 [Jan. 10, 1961], No. 927/62. Heading B6F. A carbon web feeding device in a printing mechanism having endless type belt 10, Fig. 1, movable along a print line, hammers 20 arranged along said print line and a carbon web 21, fed from a supply roll 22 to a winding roll 26, comprises a constant speed electrical motor 27 and associated gearing for advancing the carbon web in the said direction and a periodically operated detection device to cause a correction of misalignment due to the frictional contact of the web 21 with the moving types 11. A detecting lever 54, whose detection element 56 senses the misalignment of the carbon web from a home position and a restoring lever 40, carrying a roller 42 for restoring the misaligned carbon web back to said home position, the restoring lever 40 being operable in response to the detection of misalignment by the detection element 56, the detection and restoring levers being operable periodically in timed relationship with the advance of the carbon web. If during a printing operation the detection element 56 is placed on to a carbon web guide plate 25, Figs. 1 and 2, by the detection lever 54 upon actuation by a roller 70, fixed to a gear 29, and remains in a vertical position to indicate misalignment of the carbon web, then the restoring lever 40 will cause an interposer pawl 60 to be urged in an upward direction into contact with its leaf spring 62, biased by a pin 65 of the raised lever 54, to thereby enable a spring 46 to displace the restoring lever 40 and apply the restoring roller 42 to the surface of the carbon web 21. Since the axis of the restoring roller is skewed relative to the direction of motion of the carbon web, the frictional contact between the roller, carbon web and guide 25 results in an application to the carbon web of a lateral restoring force in opposition to the misaligning drag force. When during a further cycle the detection element 56 is placed on to the guide 25 and comes to rest on the surface of the carbon web, i.e. there is no misalignment, the advancing carbon web displaces the detection element 56 from a vertical to a horizontal position, Fig. 3, whereupon the detection lever 54 is lowered until its shaped upper portion engages a pin 41 and the pawl 60, during a subsequent displacement of the restoring lever 40, by the rotating roller 70, drops to engage with its detent 64 a stop edge 50 of the restoring lever 40 so as to prevent the roller 42 from being urged into frictional contact with the surface of the carbon web. Specification 919,653 is referred to.