Cutting units for cutting material in bands into strips

In a cutting device for cutting a band of material into strips of predetermined width comprising a frame which has an upper beam (10) and a lower beam (12), first roller means (16) for feeding said band of material and second roller means (18) for withdrawing the strips of said material, and several cutting units for dividing said band into strips of predetermined width, the improvement wherein each cutting unit comprises a first support (48) carrying a rotatable blade (34) which is translatable along said upper beam, a second support (66) carrying a rotatable counterblade (36), which is translatable along said lower beam, said first support being slidably secured to said upper beam, a gudgeon (58) for selectively fixing said first support said second support, motor means for moving said blades along said upper and lower beams, means for locking and unlocking said first support carrying said rotatable blade to said upper beam and, in synchronism, for disconnecting said second support carrying said counter-blade from said first support, said means comprising a single pressurized fluid tube (40, 42), a pair of pistons (50, 56) driven by said pressurized fluid, one of said pistons being operable to fix said first support to said upper beam and the other piston being operable to fix the gudgeon of the first support to the second support, said pressurized fluid being fed to locking and unlocking means of said first support and said blade and said counter blade means to lock and unlock said second support and performing one of the following combinations of operations alternately;

• locking the first support carrying said blade to said upper beams and in synchronism, operating the gudgeon so as to disconnect the second support carrying the counter-blade from the first support, and unlocking the first support carrying the blade and in synchronism operating the gudgeon so as to connect the second support.