Abstract: Rotary die cutting apparatus wherein the die blanket is mounted with respect to the anvil head such that both longitudinal and transverse relative movement is permitted between the die blanket and the anvil head during operation of the apparatus.

Abstract: 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. Such an apparatus 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. According to the invention, each knife is secured to a knife holder consisting of a bridge-like member having an inherent elastic compressibility in the radial direction, which in the fashion of a beam with a plurality of supports is supported by the cutting roller on two end supports and on one or more intermediate supports. The supports are preferably adjustable in the radial direction, and particularly consist of wedges.

Abstract: A blade quality monitor for use with cutter reels having specifically identifiable blades utilize a sensor to detect the position of a physical anomaly on the reel. Additional sensors sense the force at the interface between the cutter reel, the material wrapped thereon and the associated pressure roller. The position of the physical anomaly is correlated with the sensed force to determine the magnitude thereof at each blade which is indicative of the condition of the blade with respect to sharpness or intactness.

Abstract: A rotary die-cut apparatus, in which a die roll cooperates with a resiliently covered anvil roll for die-cutting carton blanks passed therebetween, incorporates a constant mesh gear train between the die roll and the anvil roll for providing an infinite hunting ratio between the rolls. This provides more uniform wear of the anvil roll cover and prolongs its effective life. Preferably, this gear train includes a harmonic drive having a wave generator cam rotatable by a trim motor. An arrangement for sensing changes in diameter of the anvil roll due to wear of its cover may provide an input for determining the speed of the trim motor. A resurfacing mechanism for removing the outer surface of the cover when worn may provide this input. A pulse generator is preferably incorporated in a controller of the trim motor for periodically making random changes in the speed of the trim motor.

Abstract: A veneer clipper of rotary type is disclosed wherein a cutting knife carried by an intermittently rotatable knife carrage roll cuts through a veneer sheet moving past an anvil roll. The clipper has a plurality rotatable back-up rolls which are movable reciprocally toward and away from the carriage roll. In their operative position, the back-up rolls are pressed against the circumferential surface of the carriage roll for bracing the same to counteract the reactional pressure exerted by the anvil roll during veneer cutting. There is provided means for driving reciprocally the back-up rolls in conjunction with the intermittent rotation of the knife carriage in such a way that the back-up rolls may be kept in pressing contact with the knife carriage roll at least while the veneer sheet is being cut by the knife and then moved away from the surface after each such cut.

Abstract: A holder for mounting a knife blade in a rotating roll. The holder comprises a plural pairs of clamp members for holding a knife blade with its interior edge against a reference in a rotating roll so as to adjustably position the cutting edge of the blade along the length of the roll. Each clamp member has opposed planar surfaces for contacting a segment of the blade and each clamp member is adjustable to position its planar surface in a direction generally perpendicular to the plane of the blade. Each clamp member is also adaptable to align its planar surface to the blade direction along the length of the roll as a clamping force is applied. When clamped, the blade contacting surface of at least one of each pair of clamp members has a fixed angle so as to resist a cutting force acting perpendicular to the plane of the blade at its cutting edge.

Abstract: There is provided an apparatus for applying constant pressure to a plurality of anvil rollers for crush-scoring used in combination with crush-scoring cylinders having protrusions extending from the surface thereof. Each anvil roller is supported in a substantially frictionless manner and the constant pressure is supplied by a flexible diaphragm acting on a plunger which can move substantially without friction in a pneumatic cylinder.

Abstract: A stamping device for cutting holes in paper sheets such as corrugated cardboard including a pair of identically shaped one-piece mount bases each of which is slidably mounted on and fixed to a rotatable upper and lower shaft for rotation therewith, each of the mount bases having a slot therein for engaging a yoke plate to adjust the position of the mount bases along a respective shaft. An anvil is slidably disposed on one of the mount bases with the anvil being freely rotatable with respect to the mount base. A knife base is slidably disposed on the other mount base and is keyed to the other mount base for rotation therewith, the knife base having a cutting tool disposed thereon for cutting holes in the paper sheet. A pair of identically shaped retaining plates are fixed to each of the mount bases with one of the retaining plates engaging the anvil for positioning the anvil on one of the mount bases and the other retaining plate engaging the knife base for positioning the knife base on the other mount base.

Abstract: The method comprises cutting a glass wool blanket with a circular cutting grid having elastomeric plugs in the grid spaces. The cut columns and the plugs are both compressed. The cut columns are ejected by expansion of the plugs.

Abstract: A perforating apparatus wherein two rolls define a nip for a running web of paper which is provided with rows of transverse perforations by tools at the periphery of one of the rolls. The rolls are driven in opposite directions by a timing shaft through the medium of a system of gears including an intermediate gear which indirectly drives the one roll and is directly or indirectly mounted on an eccentric. The eccentric is driven by a power train including a differential one output shaft of which carries the eccentric and another output shaft of which is normally held against rotation but can be turned by a worm to thereby change the phase of the one output shaft relative to the input shaft of the differential to thus compensate for eventual inaccuracies in the distribution of perforating tools at the periphery of the one roll.

Abstract: A machine and method to operate the machine to provide a plurality of valve-like perforations in the rubber-like backing of a nap mat or carpet by delivering the nap mat or carpet to and under a spiked roll. The machine includes a plurality of narrow bands located longitudinally of the machine to guide the nap mat or carpet away from the spiked roll after the spikes or pins on the roll have entered the rubber-like backing material to form the valves therein.

Abstract: A machine and method to operate the machine to provide a plurality of valve-like perforations in the rubber-like backing of a nap mat or carpet by delivering the nap map or carpet to and under a spiked roll. The machine includes a back up roll with grooves therein which prevents grooving of the conveyor belt by the pins or spikes on the spiked roll.

Abstract: Method and apparatus for cutting elongated material into short lengths is provided. The method features the steps of compressing the elongated material at discrete intervals transversely; slightly tensioning the elongated material along its length between intervals; pressing the slightly tensioned elongated material between intervals against a cutting edge; and cutting the elongated material with the cutting edge. The apparatus features a pair of cooperating rolls rotating in opposite directions and between which the elongated material passes. The cutting roll has a plurality of radially extending cutting blades as well as a plurality of radially extending projections, at least one of the projections being located on each side of a cutting blade and extending further radially from the cutting roll than the blades. The second roll is formed of an elastic material and is engaged by the projections in succession to compress the elongated material therebetween.

Abstract: In a rotary printing press with a blanket cylinder (2) and an impression cylinder (3), the blanket is removed and replaced by a base sheet (5). On this base sheet (5) are arranged strips (6). The arrangement of the strips (6) corresponds to the perforation, stamping or creasing to be produced in the paper or cardboard passing through the rotary printing press. On the impression cylinder (3) is arranged a smooth protective sheet (7). Both sheets (5) and (7) can be used several times and can be installed or removed rapidly by means present on the machine.

Abstract: Method and apparatus are provided for forming glass filaments wherein a transfer guide means is movable between a strand threadup position and a transfer zone immediately adjacent the primary attenuation means, said transfer guide being adapted to move a strand about to be restarted which is being advanced by a secondary attenuation means into contact with the primary attenuation means to be advanced thereby and to release such strand when said transfer guide is at a predetermined zone to permit the transfer of such strand being advanced by the secondary attenuation means to the primary attenuation means in the absence of reducing the speed of the primary attenuation means.

Abstract: An apparatus for winding strand of glass fiber filaments is disclosed. The apparatus comprises at least one takeup collet on which a strand of glass fiber filaments is wound, a guiding mechanism for guiding an end portion of the strand which has started being drawn off from a spinning bushing to a predetermined position below the spinning bushing on a stream of a water, and an auxiliary winder mechanism rotatable for catching and winding the guided end portion of the strand. The auxiliary winder being moved toward said takeup collet when the end portion of the strand is under a condition capable of being transferred onto the takeup collet for bringing the strand into contact with the takeup collet within a winding zone of the takeup collet. An associated method therefor is also disclosed.

Abstract: A cover for a cutter reel used in a staple cutting apparatus of known type is formed by a plurality of circular segment elements joined together by fasteners to form an annular cover member encircling a cutter reel member. The annular cover member of the invention is thereby adapted for use with cutter reels having a wide variety of blade configurations.

Abstract: A rotary cutter for a printing press directs a web between a knife cylinder and an opposed anvil cylinder. The outer surface of the knife cylinder mounts one or more knife blade assemblies each having a sandwich construction. Each assembly includes at least one and usually two blades separated by a spacer bar. The assembly also includes a perforator blade and an ejector bar located on opposite sides of the spacer bar and set in recesses formed on the sides of the spacer bar. The perforator blade has laterally spaced sets of chisel-like teeth that impale trim pieces cut by the blades. The ejector bar reciprocates radially within the assembly to remove the trim piece from the teeth. The assembly is held together by two sets of bolts that allow the location of the blades to be set independently. A set of half rings each carrying radially projecting locating dowels are nested in circumferential grooves formed in the knife cylinder. Each ring is aligned against locating pins mounted in the knife cylinder.

Abstract: A rotary cutter for a printing press directs a web between a knife cylinder and an opposed anvil cylinder. The outer surface of the knife cylinder mounts one or more knife blade assemblies each having a sandwich construction. Each assembly includes at least one and usually two blades separated by a spacer bar. The assembly also includes a perforator blade and an ejector bar located on opposite sides of the spacer bar and set in recesses formed on the sides of the spacer bar. The perforator blade has laterally spaced sets of chisel-like teeth that impale trim pieces cut by the blades. The ejector bar reciprocates radially within the assembly to remove the trim piece from the teeth. The assembly is held together by two sets of bolts that allow the location of the blades to be set independently. A set of half rings each carrying radially projecting locating dowels are nested in circumferential grooves formed in the knife cylinder. Each ring is aligned against locating pins mounted in the knife cylinder.

Abstract: A rotary cutter for a printing press directs a web between a knife cylinder and an opposed anvil cylinder. The outer surface of the knife cylinder mounts one or more knife blade assemblies each having a sandwich construction. Each assembly includes at least one and usually two blades separated by a spacer bar. The assembly also includes a perforator blade and an ejector bar located on opposite sides of the spacer bar and set in recesses formed on the sides of the spacer bar. The perforator blade has laterally spaced sets of chisel-like teeth that impale trim pieces cut by the blades. The ejector bar reciprocates radially within the assembly to remove the trim piece from the teeth. The assembly is held together by two sets of bolts that allow the location of the blades to be set independently. A set of half rings each carrying radially projecting locating dowels are nested in circumferential grooves formed in the knife cylinder. Each ring is aligned against locating pins mounted in the knife cylinder.

Abstract: An apparatus and process is described for deflecting a continuous yarn moving along a first to a second path to lay flat on a surface of an upstream roll of a pair of rolls at least adjacent a cutting zone defined by the circumferential contacting surfaces of the rolls of a cutting machine. The first path of movement is above and in a zone between the sides of one roll, the blade-carrying roll, which may comprise either the upstream or downstream roll, and the yarn is deflected at such time that it is being drawn at an operational speed of movement and at a speed equalized with the drawing speed of movement of other yarns.

Abstract: A cutting device for cutting threads into predetermined lengths. The device has a first rotatable smooth faced drum and a second rotatable blade bearing drum having a plurality of radially extending circumferentially spaced cutting blades on the outer periphery thereof. Centrifugal force responsive means comprising fins connected to a deformable ring are positioned between the blades and on rotation of the drums act to press a thread onto the smooth faced drum. The blades are connected to the blade bearing drum only at their ends.

Abstract: A method of manufacture of staple glass fibers by drawing a plurality of glass filaments, from a bushing and chopping them directly into staple fibers without intervening winding and storage is characterized by initiating the drawing by forming the filaments into a coil on the circumference of an auxiliary roller, forming an initial winding by rotating the roller with progressively increasing surface speed until the filaments advancing towards the roller attain the normal production drawing speed for the bushing, then diverting the filaments while still travelling at that speed, and without breaking them, into driving contact with a cutter back-up roll driven with substantially the same surface speed as the production speed, advancing the diverted filaments by means of the roll into a cutting zone whereat they are both severed from the initial winding and continuously chopped into staple fibers.

Abstract: A continuous cutter ring or hoop having relatively thick, large-angle chisel teeth to bend and break attenuated glass fibers in a glass fiber chopping assembly is disclosed. The continuous cutter is an annular ring or hoop of steel or other hard material which is formed having an outer circumference provided with integral, regularly spaced, raised cutting teeth. The continuous cutter is secured on a suitable cutter wheel which cooperates with a second wheel having an elastomer cot around its circumference with the glass fibers to be severed passing between the continuous cutter and the elastomer cot. The cutter teeth are generally chisel-shaped and sever the glass fiber strand without cutting or destroying the elastomer cot. The integrally formed cutter teeth will not separate from the cutter ring and are not subject to being misaligned.

Abstract: A cutting head for a cigarette filter attachment machine, for cutting a filter attachment web at regular intervals in cooperation with a cutting drum comprising a rotary member which carries one or more knives and is mounted on a movable carrier so as to be movable towards and away from the cutting drum, and including a fluid-powered actuator which is arranged to urge the cutting head towards the cutting drum.

Abstract: Apparatus for drawing newly-spun and dressed glass filaments from a bushing comprises, in combination, a rotary cutter constituted by a blade roll with radially directed blades projecting from its surface and a second, back-up roll having a resilient surface, said rolls being mounted with their axes substantially parallel and with at least the tips of the blades in contact with said resilient surface to define a cutting zone for the cutter, together with an auxiliary, independently driven start-up roll, variable speed drive means for accelerating said auxiliary roll to a surface speed at least equal to the surface speed of the back-up roll under production conditions, and guide means operable to divert a bundle of filaments being wound on said auxiliary roll to the surface of the back-up roll and thereafter into the cutting zone of the cutter, whereby the filaments are cut into staple fibres. A method of manufacturing staple fibres based on the use of above apparatus is also disclosed.

Abstract: There is provided a rotary die cutter for effecting a punching and scribing on a sheet which is fed between a die cylinder and an anvil cylinder disposed in parallel with said die cylinder. The die cylinder is adapted to be rotated in a predetermined direction and provided on its peripheral surface with a knife and a scribing rule. The anvil cylinder is adapted to be rotated in the opposite direction to the die cylinder and provided on its peripheral surface with an anvil for receiving the knife and the scribing rule. There is a mechanism for adjusting the clearance between the die cylinder and the anvil cylinder. A blade carrier is disposed adjacent to the anvil cylinder and slidable in the axial direction of the anvil cylinder. A cutting blade capable of cutting the anvil surface is attached to the blade carrier in such a manner as to move toward and away from the axis of the anvil cylinder.

Abstract: Apparatus for severing continuous lengths of hollow fibers into predetermined, equal lengths for use as chemical vapor dispensers is provided.

Abstract: A rotary die cutter is provided having a knife cylinder, provided on its peripheral surface with a punching blade, and an anvil cylinder around which is wound an anvil against which the punching blade is urged in punching material from cardboard passing between the knife cylinder and the anvil cylinder. The cylinders are driven by meshing gears disposed at the ends of the cylinders and having different numbers of teeth. A pair of helical gears are disposed at one end of the anvil cylinder. One of these helical gears is attached to the anvil cylinder and the other is connected to one of the meshing gears. A mechanism is provided for causing axial movement of the anvil cylinder. This axial movement is converted into rotational movement of the anvil cylinder by the relative movement of the helical gears.

Abstract: An improved rotatable anvil is provided. The anvil is of the type useful to cooperate with a rotatable die cylinder in manufacturing paper blanks and the like. The anvil comprises compressible first (inner), hard second (intermediate) and hard third (outer) concentrically disposed and axially extending layers interbonded upon a core thereof. The second and third layers are of different hardnesses. The anvil is made by providing a hollow cylindrical shell, mounting the shell concentrically about the core, injecting a polymerizable fluid between the shell and core assemblage and holding the mounted assemblage for a time sufficient for substantially complete polymerization.

Abstract: A cutting roller 2 of a glass filament chopping apparatus mounts a plurality of spaced, axially parallel cutting blades 19 held in receiving grooves 20 by retainer strips 21. The peripheral flange surfaces 24, 25 of the cutting roller on the opposite ends of the roller drum 18 are raised to almost the radius of the cutting blade edges, and serve as driving engagement surfaces when the rotating cutting roller is biased into contact with a feed roller 1.

Abstract: A rotary die cutting and scoring machine including a free wheeling resiliently covered anvil roll, an adjustable pusher having a velocity profile insuring that the velocity of the leading edge of the fed sheets matches the peripheral speed of the cutting roll, guides for guiding the side edges of the fed sheets maintaining their guide services parallel to the direction of feed and a reciprocating cutting tool for removing a selected portion of the resilient coating on said anvil roll to produce a fresh anvil surface. The machine also includes a support plate located on the reciprocating pusher to insure accurate feeding of warped sheets.

Abstract: This invention pertains to an improved blade retaining means for a blade roll used in a chopper assembly which severs continuous lengths of a material into discrete increments. Prior art devices provided blade retaining means which facilitated stress-inducing vibrations and generated stress concentrations in the ends of the blades. Attempts to cushion the blades using an elastomer blade restraining insert were incapable of eliminating contamination of the work product due to a severing of the insert when the blades were installed and used. Other blade retaining means were incapable of reuse and prevented use of the chopper blades directly from the manufacturer, i.e., all of the blades had to be cut to an exact and equal length. Accordingly, the present invention provides an improved blade retaining means comprising an annular blade retainer 52 positioned at each end of a blade roll cylinder member 50 wherein a side surface of each of the blade retainers 52 has at least one annular groove 62.

Abstract: A die stamping device for cutting, scoring or creasing a pattern of shapes onto laminar material, comprises a die cylinder having a solid cylindrical core with a coating of setting material such as plastics in which are fitted cutting or scoring blades the radially outer surfaces of which define the pattern to be cut or creased onto laminar material passed in sheet or web form between the die cylinder and a smooth pressure cylinder, which may be provided with cooperating elements, such as resilient blocks or engraved recesses to cooperate with the scoring or creasing blades; the die cylinder is made by a process involving forming a pattern on the outer surface of the coating by photographic techniques, and then removing the coating from the solid cylindrical core to facilitate cutting out the openings to receive the blades.

Abstract: An improved apparatus for cutting material such as filamentary tows into predetermined lengths comprising (a) a cutting assembly including a plurality of spaced apart knife edges secured to a mounting member at equal radial distances from a point on said mounting member thereby forming a reel, each of said radial distances in every instance being less than the distance from said point to the periphery of said mounting member; (b) said cutting assembly having means adapted to receive successive wrappings of material to be cut in contact with a plurality of said knife edges so that no relative movement occurs between said material and said knife edges longitudinally of said material; and (c) means for forcing said material between adjacent knife edges thereby severing said material into lengths of controlled dimensions, wherein the improvement comprises: means for preventing at least most of said knives from moving in a direction longitudinal of said knife edges.

Abstract: A method and apparatus for extending the useful life of resilient covers on anvil rolls of rotary die cutters by causing the die cutting rules to penetrate the covers at sequential incrementally small circumferentially spaced locations around the cover by adding to the speed of rotation of the anvil roll relative to the speed of the die holder roll. Lateral reciprocation of the anvil roll is translated to rotary motion by a gear and pivot lever arrangement, such rotary motion being added to the normal speed of the anvil roll.

Abstract: A catalyst strand sizer is described which produces catalyst pellets of uniform preselected length without producing an excessive amount of fines. The catalyst sizer comprises two fixed rotatable rolls wherein one roll has a compressible surface and the other roll is covered with a wire mesh of selected dimensions whereby when the catalyst strand extrudate is passed between said rolls, the strands are broken into catalyst pellets of preselected length.

Abstract: A rotary anvil construction, method of locking a die-cutting mat on such construction, and locking wedge for use with such construction and method are provided wherein the locking wedge is an immobile wedge and has locking surfaces which are adapted to have cooperating locking surfaces on flanges of a die-cutting mat of the rotary anvil construction snap-locked thereagainst.

Abstract: An idler roll adapted to engage a moving textile strand is comprised of a plurality of substantially parallel, spaced apart cylindrical rods positioned along a base circle wherein the diameter of the base circle, the diameter of the cylindrical rods and the distance measured along the base circled between the center lines of adjacent rods are determined according to specific predetermined relationships.

Abstract: A dispenser for sheets of web material, such as paper towels, from a supply roll, including a housing, means for holding a supply roll of the web material, and means for separating a sheet of the web from the supply roll operable in response to a user pulling the sheet from the housing and arranged to present at least a portion of the leading edge of the web ready for a user to seize for the dispensing of a further sheet as a direct result of the user pulling the previous sheet from the dispenser.

Abstract: A cutting device for cutting sheets of material wherein a cutting member co-operates with a bed of upstanding pins which support the sheet. Although the cutting member may be a knife, it is preferably composed of a line of upstanding pins which are sufficiently long to penetrate through the material to be cut and to enter the bed of upstanding pins. The cutting device may comprise two drums mounted for rotation in opposite senses about parallel axes, one drum carrying the cutting member and the other the bed of pins, the tips of the pins being aligned with the cylindrical surface of their associated drum.

Abstract: A catalyst strand sizer is described which produces catalyst pellets of uniform preselected length without producing an excessive amount of fines. The catalyst sizers comprises two fixed rotatable rolls wherein one roll has a compressible surface and the other roll is covered with a wire mesh of selected dimensions whereby when the catalyst strand extrudate is passed between said rolls, the strands are broken into catalyst pellets of preselected length.

Abstract: A diecutting apparatus is disclosed which accepts interchangeable die cylinders of a variety of lengths and diameters. Rapid replacement, adjustment and reversal of the die is possible. The station has a support bar for mounting the die cylinder and a slidable support for the die cylinder bearing blocks. The bearing blocks slide horizontally along the support bar to accept die cylinders of a variety of lengths. The support bar is mounted at each end on transverse slides which slide vertically to accept die cylinders of a variety of diameters. Mounted above the die cylinder support bar is a support slide on which are mounted contact rollers and pressure cylinders for applying a biasing force to the die cylinder. The slides may be fixed in place for each particular die cylinder used. The pressure cylinders and contact rollers act on bearing surfaces on the die cylinder.

Abstract: A blade roll for a chopper of glass fiber strands having elastomer means for supporting the blades and blade retaining means to cooperate with the elastomeric means for restraining movement of the blades in both a circumferential and radially outward direction.

Abstract: A cover for a rotary anvil which includes in combination, a main body of flexible material having ends with alternating lugs and recesses adapted to interlock with one another, and a comparatively inelastic reinforcing sheet of metal or the like attached to the inner surface of the main body and having ends adapted to meet or overlap when the ends of the main body are interlocked, one end of the reinforcing sheet protruding from the lugs of its associated main body end so that the meeting of the reinforcing sheet ends does not coincide with the interlocking surfaces of the lugs and recesses. A shim member may be provided on the inner surface of the reinforcing sheet and extending circumferentially a sufficient distance to underlie the interlocking surfaces of the lugs and recesses to there raise the cutting surface of the cover.

Abstract: Anvil structure for use in rotary die cutting apparatus is disclosed to include a shaft mounted anvil head, a slip ring slidably mounted on the anvil head and a die blanket releasably secured to the slip ring.

Abstract: Locking means for a cutting die blanket is disclosed to include male and female locking elements which, when engaged, generate a state of compression in the blanket coating material such as to achieve uniform resistance to penetration throughout the surface of the blanket.

Abstract: A die cutting roll carries outwardly projecting die cutting blades, and a parallel back-up roll carries a resilient mat which is engaged by the blades. The rolls are driven by a set of helical gears, and the back-up roll is reciprocated axially by a set of air cylinders, so that the back-up roll moves in a helical direction when the blades are out of engagement with the mat to avoid a repeating pattern of blade engagement with the mat and thereby extend the useful service life of the mat. The sheets to be die cut are successively fed between the rolls from the bottom of a stack by a reciprocating feed member driven by oscillating arms pivotally supported by a shaft. The shaft may be rotatably adjusted on an eccentric axis while the sheets are being fed for quickly phasing the feed of the sheets relative to the rotation of the die cutting roll to obtain precise registry of each sheet with the die cutting blades.

Abstract: A method and apparatus for the chopping of glass strands is disclosed. The back-up or cot roller for the chopping blades includes an annular cutting surface or ring which is mounted on an expandable wheel, such as an inflatable wheel. By varying fluid pressure within the inflatable wheel, variations in the resiliency of the cutting surface are realized. This allows for a smoother operation of the chopping system and increases the life of the cutting surface. Further, the expandable wheel around which the cutting surface rides will adapt for variations in the thickness of the annular cutting surface and still give a consistent mesh with the cutting blades. Thus, it is now possible to employ cutting rings having inconsistent inner and outer diameters and to resurface the cutting surface by grinding that portion of the surface which has been partially gouged by the cutting blades to an even surface once again and thus to reuse the cutting ring.

Abstract: The invention provides a rotary cutter drum for use in apparatus for cutting continuous web material into discrete lengths in which the polar moment of inertia is kept to a minimum. The drum consists of a prefabricated metal load bearing member to which a block, on which a knife blade is mounted, and a balancing member are secured. The load bearing member, the block and the balancing member are then covered in a lightweight material such as an integral skin polyurethane rigid foam material arranged so that the outer surface of the whole drum is rotational symmetrical, the surface being interrupted to allow for the mounting of the knife blade.