GB1420952A - Corrugation-forming machines - Google Patents

Abstract

1420952 Corrugation-forming machine COVRAD Ltd 9 May 1973 [16 May 1972] 22853/72 Heading B3E [Also in Division F2] A corrugation forming machine comprises two rotatable die rolls 10, 11 having intermeshing teeth 14 between which material 15 to be corrugated is passed, a drive for rotating the rolls, and an oscillating device arranged to cause the relative angular velocity of the die rolls to change during their rotation. The rolls 10, 11 may be spring-loaded towards one another, and a sinusoidal oscillation is imparted to one or both of the rolls about their axes of rotation so that at any one time the or each oscillated die roll rotates at a speed faster, slower or equal to the mean angular velocity. Rolls 10, 11 are interconnected by meshing equal-ratio spur gears 21, 22, Fig. 2, connected to the rolls by shafts 23-28 and universal joints 29-32. Shaft 27 is carried in bearings in a framework including plates 33, 34 pivoted about the axis of shaft 28. Gear 21 is connected through step-up gears 37-40 to an eccentric 41. The assembly is driven by an electric motor connected to one of the shafts 24, 36, 42 or 43. Upon rotation of roll 10 eccentric 41 is caused to rotate and in turn causes rod 44 to oscillate and the plates 33, 34 to rock in a sinusoidal manner about shaft 28. Gear 21 rolls back and forth around gear 22 to impose a sinusoidal torsional oscillation on the steady speed of the latter. A corresponding angular velocity pattern is transmitted to roll 11 via shafts 23, 25, 27 and joints 29, 31. A lobed cam may be used instead of a simple eccentric having a step-up ratio from shaft 36 to shaft 43 equal to the number of teeth on each roll. In an alternative embodiment, Fig. 3 (not shown), gear-wheels (45), (46) are driven by worm-wheels (47), (48). An electric motor (62) drives the wheels (47), (48) through Hooke's joints (55)-(58) and intermediate telescopic splined shafts 59, 60. The teeth 14 of each roll may be provided with louvre-cutting devices 65, Fig. 4, formed on the flanks 20 and which are each formed as inserts in the teeth. Projections 66 of the devices form corresponding slits and depressions in the aluminium foil strip 15. The die rolls 10, 11 are made up of thin discs, which are assembled using through-bolts to form a laminated roll (67), Fig. 6 (not shown). The teeth 14 of the rolls may have different forms, e.g. the tips 18 and roots 19 may each consist of points, Fig. 7 (not shown), flats, or slightly convex portions.