GB1214855A - Apparatus for winding and unwinding strip material - Google Patents

Abstract

1,214,855. Feeding webs. CIBA Ltd. 23 April, 1968 [28 April, 1967], No. 19193/68. Heading B8R. Apparatus for winding or unwinding strip material from a spool 2 coupled to a belt-driven pulley 4, comprises first and second pairs of drive rollers 22, 23 and 24, 25 respectively, for the belt 5, and a brake 26, 27 for the belt, the rollers and brake being controlled by a cam member 38 movable by a web-tensioning lever 7 attached to a spring 44 so that in the upper position of the lever 7 the rollers 22, 23 engage the belt 5 to drive it in one direction i.e. clockwise, Fig. 1, for unwinding, in the middle position of the lever 7, the brake 26, 27 engages the belt 5 to bring it to rest, and in the lower position of the lever 7 the rollers 24, 25 engage the belt to drive it in the other direction i.e. anticlockwise, Fig. 1, for winding. The rollers 22, 24 have fixed axes and the brake part 26 is fixed. The rollers 23, 25 and the brake part 27 are carried by levers 28, 29, 34 respectively having springs attached tending to move the rollers, &c., into engagement with their co-operating members. Both the rollers of each pair or the fixed rollers only may be driven. Pins 40, 41, 42 on the levers 28, 29, 34 are engaged by a slot 39 in the cam member, the slot 39 having a depression E into which the pins can move, so that in the upper position of the lever 7, the pin 40 drops into the recess E and rollers 22, 23 engage the belt 5 to drive in an unwinding direction. Similarly, as the lever 7 falls, one or other of the pins 41, 42 moves into the recess to cause braking or reverse driving of the belt. The belt 5 is tensioned by rollers 12, 13 mounted on levers 14, 15, loaded by springs 18, 19. During unwinding, a stop 20 limits movement of the lever 14 so that tension is applied only by the roller 13 and during winding a stop 21 limits movement of the lever 15 so that tension is applied by the roller 12. The arrangement maintains the pull of the belt 5 on the pulley 4 at a substantially constant value. Two arrangements as described may be employed, one for feeding the material to a treating station and the other for rewinding the material. There may be a lost motion connection between the lever 7 and the cam 38 to prevent continuous stopping and starting of the belt during oscillation of the lever through a small angle. In a modified arrangement, Figs. 7, 8 (not shown), a stepped pulley 4 is employed, each step being associated. with a separate belt 5, and each belt being associated with lever-carried drive rollers 23, 25. All the rollers 23 are associated with a common drive roller 22, and all the rollers 25 are similarly associated with a common drive roller 24. A separate cam 38 is provided corresponding to each belt, all the cams being fixed to the tensioning lever 7. The cams are designed so that the belt engaging the smallest diameter step of the pulley is driven by its rollers when the lever 7 is in its highest or lowest position i.e. the greatest speed is obtained, whereas in intermediate positions lower speeds are obtained. In the central position of the lever, a brake engages the belt to bring it to rest as described above.