Apparatus for dividing a continuous web of material into successive single sections

#The invention refers to an apparatus for dividing a continuous web of material into successive single sections, particularly for dividing a web of covering material into successive single bands used in the manufacturing of filter-tipped cigarettes, which comprises a rotary cutting roller with one or more peripheral radial knives which are angularly spaced apart from each other and have their cutting edge parallel to the axis of rotation of the cutting roller, and a rotary counter-roller with one or more peripheral anvils cooperating each with a knife in the cutting roller, and which may be provided with suction ports for holding on the said counter-roller the single sections cut from the web fed about the counter-roller, between this roller and the cutting roller, the knife or knives being each secured to a knife holder which is elastically yieldable in the radial direction toward the axis of rotation of the cutting roller. Such an apparatus is disclosed in the commonly owned co-pending Application Ser. No. 916,733, filed Oct. 8th, 1986.

#The object of the invention is to provide an apparatus of the above stated type, in which the knife holders are so improved as to attain an accurate alignment of the knife cutting edges parallelly to the surface of the anvils in the counter-roller, and at the same time as to permit the knives to elastically yield in the radial direction relative to the cutting roller, without using any suitable elastic means, while reducing also any noise and vibration generated by the knives hitting against the anvils in the counter-roller, and ensuring a uniform distribution of the load along the length of each knife.

#This problem is solved by the invention by the feature that each knife holder consists of a bridge-like member which is so made as to have an inherent elastic compressibility in the radial direction, and which in the fashion of a beam with a plurality of supports is supported by the cutting roller on two end supports and on at least one intermediate support.

#These and other features of the invention and the advantages arising therefrom will appear from the following specification of one preferred embodiment thereof, shown by way of a non-limiting example in the accompanying drawings, in which:

#FIG. 1 is a view in longitudinal section showing the cutting roller of an apparatus according to the invention.

#FIG. 2 is a view in longitudinal section, and in an enlarged scale, showing a knife holder on the cutting roller according to FIG. 1.

#In the figures, numeral 1 denotes the cutting roller unit of an apparatus for dividing a continuous web N of wrapping material into equally long successive single sections S. The cutting roller 1 comprises a skirt 2 which through bearings 3 is mounted for rotation about a cantilevered fixed support 4. The skirt 2 has its outward end secured to a disc 5 which in turn is secured to a driving shaft 6 rotatably mounted by means of a bearing 7 in the fixed tubular support 4. The shaft 6 is driven by means of a gearwheel 8 which is integral therewith.

#The cutting roller 1 carries on its periphery a plurality of knives or blades 9 which are parallel to the axis of the cutting roller 1 and are set in an angularly equispaced relation. Each knife 9 is secured to the cutting roller 1 by means of a knife holder (blade holder) 10. Each knife holder 10 is provided on its radially outward side with a cradle-like recess serving as seat for the respective knife 9 which has a square profile and four cutting edges. Therefore, the active cutting edge can be changed by fitting knife 9 in a different angular position into the respective seat in its knife holder 20. Each knife 9 may be secured to the respective knife holder 10 in any suitable manner, such as by means of clamping platelets 11 which are fastened to the knife holder 10 by means of screws 12 and partly overlap the said knife 9. Each knife 9 on the cutting roller 1 cooperates with a respective peripheral anvil 13 in a counter-roller 14 on which the web N to be divided into successive single sections S is fed. The cutting of said web N is effected by parting it off from its front side, through the action of the cutting edge of each knife 9 hitting against the respective anvil 13 in the counter-roller 14.

#Each knife holder 10 consists of a metal bar having in cross-section a profile which is composed of a rectangular base portion surmounted by a triangular portion having within its apex the seat for a knife 9. The skirt 2 of the cutting roller has in its periphery a plurality of longitudinal grooves 102 made in at least two annular collars 202 of said skirt 2, and a knife holder 10 can be accommodated by its prismatic base portion in each one of said grooves, which in the fashion of a beam with four supports radially bears on the skirt 2 of the cutting roller 1, in correspondence of two spaced apart intermediate supports.