GB854936A - Improvements in or relating to web driving means - Google Patents

Abstract

854,936. Driving magnetic recording tapes. ELECTRIC & MUSICAL INDUSTRIES Ltd. Aug. 21, 1957 [Aug. 21, 1956], No. 25528/56. Class 40 (2). [Also in Group XVI] Web feeding apparatus comprises a roller having a series of apertures around the periphery affording air passages into the interior of the roller, a stationary port connected both to suction and the interior of the roller, and a collar which closely surrounds the roller over a portion of its length which reduces leakage between the port and the interior of the roller. As shown, the roller 1, Fig. 1, is mounted on a spindle 2 carried by a bearing 3. The apertures 6 connect with longitudinally-arranged bores 5 which connect with arcuate apertures 9a and 9b. Passages 10a, 10b connect the apertures 9a and 9b with the ports 11a, 11b, respectively. One of the ports 11a 11b is connected to suction and the other to atmosphere, a collar 7 surrounding the roller reducing leakage between the port connected to suction and the bores 5. Thus, suction is effective to hold the web to the roller 1 only over part of the roller periphery. In a modification, Fig. 13, a roller 12 comprises coaxial cylindrical portions 16, 17, 18 providing annular shoulders. The portion 16 has peripheral grooves 20. Pins 21 inserted in holes in the portion 16, divide the grooves into arcuate portions. Portions 17, 18 are closely surrounded by a collar 19. Bores 24, 25 and 26 connect the grooves 20 with arcuate apertures such as 30a in the collar 19. The aperture 30a is connected to a channel 29a connected either to suction or atmosphere. The clearances between the roller 12 and collar 19 are small, thereby reducing leakage. In a further modification, Fig. 6, not shown, the roller is made up of alternate thick and thin discs mounted on a common shaft, the thick discs having semicircular serrations around their peripheries cooperating with bores in the thin discs, so as to exert suction on a web passing around the roller. In a further modification, Fig. 10, the roller 44 is secured to a shaft 45 rotatable in a bearing 46. The roller 44 has stepped cylindrical portions 47, 48 providing an annular shoulder 49 and bores 50, 51, 52, and 54 connecting arcuate slots 53 with a recess 68. A collar extending almost to the shoulder 49 comprises rings 57, 58, 59 and 60 held in position by a spring-ring 61 secured to a member 55 by a screw 62. The ring 59 has a portion, not shown, of part-circular shape adjacent the portion 48 and another portion 67 Fig. 11 (not shown), spaced from the portion 48 to form a recess 68, connected to apertures 69 in rings 57, 58. The apertures 69 are connected with a passageway 56, such that they form a stationary port together with the recess 68. When the roller 44 is rotated suction is communicated successively to the slots 53 to draw a web passing over the roller closely into contact therewith. The individual rings 57 ... 60 can move transversely to the roller axis to accommodate inaccuracies in the collar and roller. Specification 854,937 is referred to.