Abstract: A bucket crusher has a box-shaped bucket body defining a loading compartment and an unloading opening, a crusher unit configured to crush sheet material and having a cylinder with a plurality of crusher teeth connected to a cylinder wall, each crusher tooth of the plurality of crusher teeth extending between a proximal end and a distal end. The plurality of crusher teeth has at least one high crusher tooth and at least one low crusher tooth. The distance between the cylinder wall and the distal end of the at least one high crusher tooth is greater than the distance between the cylinder wall and the distal end of the at least one low crusher tooth.

Abstract: A grinding roll including a roll body having a cylindrical outer surface extending axially between a pair of opposite ends and a side groove formed at each end of the roll body. The side groove includes a support shoulder recessed from the cylindrical outer surface and/or from surfaces of the opposite ends of the roll body. The grinding roll includes an edge ring including a plurality of spaced receiving cavities and a plurality of wear members. Each wear member is received and retained in at least one of the receiving cavities of the edge ring. The wear members are positioned along the edge ring to define an edge of the grinding roll, and the edge ring is received within each side groove. The wear members are arranged to provide a wear protecting surface which is angled in relation to the cylindrical outer surface of the roll body. The angled wear protecting surface prevents excessive build-up of material on the grinding roll and reduces the need for maintenance.

Abstract: A multi-region twin-shaft cutting system for chopping material. The cutting system includes two shafts which are arranged in parallel and are driven in an opposed manner, each shaft is surrounded by a roll body. The system additionally includes a multiplicity of supporting elements, each supporting element is fitted radially around the roll body. The system further includes a multiplicity of severing elements which are of disc- and/or plate-like design and are each fitted symmetrically or asymmetrically tangentially to the circumferential region of the supporting elements.

Abstract: A plant vine chopper rotor drum assembly has a plurality of rotor rings spaced along, encircling, and attached to the longitudinal outer surface of a rotatable main drum tube. Each rotor ring has one or more pairs of angled mounting tabs that alternate to the left and to the right to the general plane of respective rotor ring; and the rotor rings are distributed in a cutting zone along and surrounding the longitudinal rotational axis of the drum tube with each mounting tab having a generally planar cutting blade attached. The angled blades distributed around the outer circumference of the ring cooperate one with another during operational rotation of the drum to guard each blade and the drum against the wrapping of clogging fibrous strands and other clogging material around the drum.

Abstract: An example gyratory crusher for comminuting quarry material may comprise a crushing housing having a top and a bottom and a crushing cone having a top and a bottom. The crushing housing may be positioned around the crushing cone such that the crushing housing and the crushing cone form a circumferential crushing space having a crushing throat towards the top and a crushing gap towards the bottom. The crushing throat may be configured to receive quarry material, which, once comminuted, may exit the circumferential crushing space through the crushing gap. The circumferential crushing space may be tapered towards the crushing gap to facilitate this process. The crushing housing may include a crushing wall surface with an undulated surface disposed at least near the crushing throat. Waves of the undulated surface may include wave troughs and wave peaks and extend in a circumferential direction.

Abstract: The present invention concerns a rotary cutting tool (1) with a cylindrical supporting spindle (2) and several individual blades (3) with essentially radial cutting edges, helically ground and set at regular intervals on the outer surface of the spindle, each blade (3) having a rectilinear base (4) which inserts into a slot (5) of the same shape as said base, each individual blade (3) being mechanically fixed to the spindle (2), characterized in that it also comprises two covers (8, 9) fixed to the respective bases (8?, 9?) of the spindle (2) so as to reinforce the fixing of the blades (3).

Abstract: A bowl liner for use in a cone crusher that is comprised of a pair of bowl liner sections joined to each other to define the bowl liner. Each of the bowl liner sections includes first and second ends that engage opposite first and second vertical ends of the second bowl liner section. The first and second ends include key features that limit the axial movement of the first and second bowl liner sections relative to each other. Each of the first and second bowl liner sections further include a radial key and mating key slot to limit the radial movement between the bowl liner sections. The vertical joint between the bowl liner sections includes an inner relief that allows for manganese growth during use of the bowl liner.

Abstract: An apparatus a circular blade device to produce consistent separated portions of a product to produce a severed portion, pulled and/or shredded product from cooked meat items or other food products as well as a more consistent sized crumble with precooked sausage based items. One embodiment can include a 16 point star shape with angled head or teeth to allow for the pulling of a consistent size product.

Abstract: An apparatus for fracturing in which: a fracturing tooth is formed so as to have a larger base part than a top end; a fixing cover is formed along a longitudinal direction of rolls and is provided with fixing holes for fracturing teeth arranged along the longitudinal direction, expanded parts which are formed by expanding both sides of the fixing holes, and an indented part which is formed by narrowing a part between the fixing holes with respect to the expanded parts; the base part of the fracturing tooth is held between the roll and the fixing cover fixed on the roll and the indented part and the expanded part of the adjacent fixing cover are engaged with each other in fracturing teeth unit, so that the fracturing teeth are arranged in a staggered manner.

Abstract: An apparatus for fracturing in which: a fracturing tooth is formed so that a base-end portion has a larger diameter than that of a top-end portion, and a tapered part is formed at the base-end portion so as to expand from the top toward the base; a fixing cover is formed along a longitudinal direction of rolls; in the fixing cover, fixing holes for fracturing teeth are formed along the longitudinal direction so that the fracturing tooth is inserted therein; each of the fixing holes has a slope in which the tapered part is in contact at a surface; a fracturing teeth unit is fixed to the roll in a state in which the top-end portion of the fracturing tooth is protruded from the fixing hole radially-outwardly of the roll and the tapered part is wedged between the slope of the fixing hole and the roll.

Abstract: A blade set for paper shredders is disclosed. In one embodiment, a notched blade having at least two notches in proximity to a central hole is brought into contact with a mating blade also having a central hole. Force is applied to the mating blade in such a fashion as to displace some of the body of the mating blade into the notches. This acts to substantially secure the blades together. In another embodiment, the notches are disposed on the edge of the blade and through the periphery. In yet another embodiment, one blade can have holes and not notches.

Abstract: A roller press, in particular for processing highly abrasive materials, includes at least two press rollers, each of which is provided with a wear protection layer arranged on a base body. The wear protection layer includes plate-shaped and pin-shaped wear resistant material elements. The plate-shaped, wear resistant material elements are applied to surfaces of two opposed edge areas of each base body by sintering with or without pressure, preferably by a hot isostatic pressing operation. The pin-shaped wear resistant material elements are arranged in a central section of each base body extending between the edge areas. A method of producing a wear protection layer, in particular for a press roller, is also provided.

Abstract: A grinding assembly for the comminution of material that enhances the durability of the side edges of both a grinding roll and a flange roll. Both the grinding roll and the flange roll include a wear ring that is received within a side groove formed at each end of a cylindrical roll body. The wear ring includes a series of spaced receiving cavities that each receive a wear member. Each wear member includes a radially outer surface and an axial end face to enhance the durability of the edge of the roll body. The edge ring is retained on the roll body by a series of connectors that pass through the edge ring. In the flange roll design, a flange ring is attached to the roll body by a series of connectors that also secure the edge ring to the roll body.

Abstract: The grinding roller of a roller mill according to the invention consists essentially of a roller shaft, a main roller body and an external wear ring having a wear protection, wherein the connection between the roller shaft and the main roller body is formed by a shrink fit. The main roller body is formed by at least two coaxially arranged intermediate rings.

Abstract: An apparatus for fracturing polycrystalline silicon having: a pair of rolls which are rotated in a counter direction each other around parallel axes; a plurality of fracturing teeth which are provided on and protruded radially-outwardly from outer peripheral surfaces of the rolls, and are made from cemented carbide or silicon material; and resin covers being wound around the roll in a state in which the fracturing teeth penetrate thereof so as to cover the outer peripheral surfaces of the rolls, and fractures fragments of polycrystalline silicon between the rolls.

Abstract: An apparatus for fracturing polycrystalline silicon having a pair of rolls which are rotated in a counter direction each other around parallel axes, the rolls is provided with: a plurality of disks layered along the axes of the rolls; and a plurality of fracturing teeth protruding radially-outwardly from the disks with a certain intervals along a peripheral direction of the disks, wherein the disks are rotated at different rotation speed from an adjacent disks, and the apparatus fracturing fragments of polycrystalline silicon between the rolls.

Abstract: The present invention relates to an abrasive roll assembly, a conveyor assembly and a milling machine having the same. The abrasive roll assembly comprises an abrasive roll element configured for milling food grains.

Abstract: A device for mixing, grinding, drying, deagglomeration, crushing, or coating of feedstock with a rotor is provided, rotating around an axis within a housing, and a stator, fixed relative to the housing, encompassing the rotor with maintenance of a radial working gap. The rotor has rotor tools, which are distributed over its outer surface and whose active edges for crushing the feedstock work together with the stator tools on the inner circumference of the stator. In this regard, the feedstock is supplied in the carrier gas stream to the working gap. For effective processing of the feedstock, it is proposed according to the invention that in the outer surface of the rotor a plurality of indentations is introduced, whereby areas between two adjacent indentations form webs, which form the active edges of the rotor tools.

Abstract: A paper shredding mechanism has two rows of shredding units rotating in opposite directions. Each unit has a flat body, with a periphery and left and right sides, and at least one piercer projecting from the periphery for piercing and cutting a paper sheet fed between the two rows. The piercer cuts in a first direction, transverse to the paper feeding direction, and has a shearing edge on each of the left and right sides, alongside the periphery. The piercer has a cutting edge which extends across the left and right sides of the body. The shearing edge of each of the units bears laterally against the shearing edge of an adjacent unit. The two shearing edges together act as shears, cutting the paper sheet in a second direction, parallel to the feeding direction.

Abstract: Provided is a roller cutter for a shredder having sufficient strength obtained by using a reduced amount of a metallic material. A roller cutter for a shredder is provided with a rotary shaft rotationally driven by a drive mechanism, finely cutting blades each including disks joined together on inside surfaces thereof, the finely cutting blades being successively mounted on and supported by the rotary shaft with the angular phase of each of the blades displaced by a predetermined angle from each other, and shaft fixation members which are fixed to the rotary shaft to thereby fix the finely cutting blades to the rotary shaft under conditions where the members have been mounted at both ends of the finely cutting blades. In this roller cutter, the finely cutting blades have folded parts forming thick-walled portions which go into contact with each other, the folded parts being formed by folding inward the sheet metal material used for forming the disks.

Abstract: The present invention discloses a smart speed control, power-saving and noise-reduction paper shredder, comprises an electric machine unit, a current inspection feedback unit, a gear-switching voltage-modulating and speed-regulating unit and a power supply, wherein an input terminal of the gear-switching voltage-modulating and speed-regulating unit is connected to an output terminal of the current inspection feedback unit, and an output terminal is connected to an input terminal of the electric machine unit; a paper shredder of the present invention applicable for an AC electric machine, an induction electric machine or a DC electric machine, wherein current required for paper shredding by the AC electric machine, the induction electric machine or the DC electric machine is detected, and the electric machine is adjusted to its best working condition, and a number of speeds including high, mid and low gears are provided and can be switched according to the actual load condition, so as to achieve the smart spee

Abstract: The aim of the invention is to provide a roll crusher for a grate cooler for cooling hot bulk material, in particular hot cement clinker, comprising several parallel crusher rolls. Said rolls are driven in opposite directions and comprise respective rotatably mounted axle tube rolls, onto each of which a large number of crusher rings that can be connected to the axle tube can be pushed. According to the invention, the crusher rings are configured in such a way that crusher elements project from the cylindrical outer face of the crusher rings, said elements being uniformly distributed both over the periphery and over the width of the crusher rings.

Abstract: A roller press (1) is described for grinding particulate material such as cement raw materials, cement clinker and similar materials, the roller press having two oppositely rotating rollers (2, 3) with one roller being movably supported relative to the other roller and with the rollers (2, 3) forming between them a roller gap (4). A co-rotating annular disc is attached to one of the rollers (2), which subject to actuation by a number of springs (7), is movable in the direction of the roller axis and which, in the area around the roller gap (4,) extends over the end surface (3a) of the other roller. The annular disc is divided into a number of ring sectors (5) over its circumference, each individually biased by springs towards the end surface (3a) of the other roller (3). Hence, it is possible to maintain the grinding bed thickness at the ends of the rollers, thereby attaining a uniform pressure distribution across the rollers, as well as uniform grinding efficiency and uniform wear on the rollers.

Abstract: A rotor and device for the comminution of input material is provided. The rotor includes a drive shaft on which a predetermined number of rotor discs are provided and over the circumference of which grinding tools are arranged. In accordance with an embodiment, it is provided that frictional connection elements are arranged between the rotor discs forming axial ends of the rotor and the shaft for transferring a torque, and that power transmission elements are arranged in a contact surface of two adjacent rotor discs and that the rotor discs can be clamped together with axially acting clamping elements.

Abstract: A round cutter-blade of a paper shredder includes a body having a surface, a periphery, and an opening formed therethrough; and at least one triangular shaped knife-edge that is integrally formed with the surface of the body and is turned over the periphery of the body. The cutter-blade can cut broken paper into short fragments, thus raising the secure requirement greatly and reducing the cost due to a reduction of thickness of the round cutter-blade.

Abstract: The present invention includes a cutting wheel device for grinding materials, the cutting wheel comprising a plurality of discrete plates mounted on an axle and cutting heads positioned between the plates. The cutting heads having a portion extending beyond the periphery of the plate. Secondary cutters are attached to the cutting head to project over an adjacent discrete plate for keeping debris from lodging between adjacent cutting heads.

Abstract: A shredder blade set with low resistance combines pressed blades and polished blades in various ways to form a shredder blade set. The shredder blade set has an appropriate friction for solving the problems with tilted or wrinkled paper due to insufficient friction or power waste due to large friction.

Abstract: A paper shredder blade includes a pair of cylindrical hobs, and each hob includes a polygonal shaft sheathed with many differential blades, allowing the differential blades to be assembled alternately. Each differential blade has two secondary blades, and an inner side of each secondary blade contains many bumps surrounding an inner rim of the secondary blade to increase a thickness and an intensity of the blade. Two abutted secondary blades are formed into one set of differential blade by abutting the bumps with the bumps, to save more than a half of materials of the differential blade, and to reduce a weight correspondingly. A cut-off edge of each secondary blade contains a reinforcing rib, allowing the edge to be thicker than the cut-off edge of an ordinary paper shredder. Therefore, when cutting off paper, the paper will not be jammed easily and can be cut off easily.

Abstract: The present invention relates to a round undulating blade for shredder, where a sheet metal is integrally formed into a round undulating blade to serve as the blades for constructing a blade module. The blade includes: a periphery; an undulating blade flank including at least two cambers having a first curvature and at least two cambers having a second curvature alternatively arranged with respect to the cambers having the first curvature; and hooked edges formed on the periphery of the cambers having the first curvature, wherein the undulating blade flank of the blade serves to cut paper along a longitudinal direction to form paper strips having double-tapering end, and the hooked edges serve to cut the strips along a horizontal direction into paper chips. These characteristics help to reduce the manufacturing cost, reduce the motor load and power consumption, to thereby enhance the market competitiveness.

Abstract: The present invention discloses a cutter structure of a paper shredder, which comprises a pull-rod (23), paper guide combs (24), cutter arbors (21), and at least one cutter-blade set composed of two cutter-blades (22), with said cutter-blade set being slipped on said cutter arbor (21), said pull-rod (23) being passing through the hole set on said paper guide combs (24), at least two lugs (222) being set on the bore (32) of said cutter-blade (22) and extending toward a cutter spoke (35), the height of said lug (222) along axial direction of the cutter-blade (22) is greater than the thickness of said cutter blades (22); with recesses (221) being set on cylindrical cutter arbors (21), the number of which is no less than that of said lug (222) which can be placed into said recess (221); said paper guide combs (24) being set between said cutter-blade sets; said paper guide combs (24) being slipped on said cutter arbor (21).

Abstract: A combinative cutting wheel of a rotary cutter of paper shredder is composed of two sets of edge rings having cutting edges on outer rings thereof, and a plastic base ring having a spacer. A center of the aforementioned plastic base ring is provided with a shaft hole which can fit with a polygonal shaft rod. The two sets of edge rings are abutted on each other and then latched on the plastic base ring to form an integral body. The two edge rings constituting the cutting wheel are pre-installed on the plastic base ring having the spacer to form an integrated cutting wheel having the spacer, enabling the two blades and the spacer which would be installed separately to become one component, so as to simplify an assembling procedure for the rotary cutter.

Abstract: A shredder for shredding data bearing substrates has a housing and shredder mechanism with cutter elements for shredding paper. The cutter elements are positioned along two shafts and interleave with the other when rotated relative to each other. At least one of the cutter elements comprises a pair of outer blades, preferably made of metal, and an inner support, preferably made of a plastic. The outer blades and inner support are aligned circumferentially to form a cross-cut tooth. The outer blades and inner support may be designed such that they are snap-fit together. The outer blades may be formed from a stamping or punching process, and the inner support may be molded.

Abstract: Compacting device for the low-metal compaction of a powder with a casing which at least in part surrounds a working chamber, with a feed arrangement arranged on the casing and feeding a powder, which is to be compacted, into the working chamber, with at least a compacting roller which is rotatably arranged in the working chamber, comprises a roller jacket and, together with an opposing wall, forms a compacting gap for compacting the powder therein, characterised in that the at least one compacting roller consists of ceramic, at least on the roller jacket.

Abstract: The invention relates to hard elements generally produced by powder metallurgy for protecting rolling press rollers from wear, this protection taking the form of grid armouring. In order to provide hard elements which can be produced relatively inexpensively and which, in particular, can again be disassembled in a relatively simple manner, even in the damaged state, from their respective roller body cutouts for the purpose of roller repair, the invention proposes prefabricated hard elements with a prefabricated central cutout which, starting from the radially inner end of the hard elements, extends over at least some of the height of the hard elements.

Abstract: The invention relates to a device for comminuting empty containers, particularly beverage bottles or cans made of plastic, particularly of PET or of tinplate, comprising a housing provided with a filling opening and with a discharge opening, and comprising a cutting unit mounted inside the housing and means for driving and controlling the cutting unit. The cutting unit contains at least two cutting rollers, which are mounted at a distance from one another with regard to their rotation axes, and the cutting mechanism containing the cutting rollers is a document shredder cutting mechanism.

Abstract: An apparatus including a pair of substantially parallel shafts. Each shaft has a plurality of axially spaced cutting blades mounted thereon such that each blade forms an oblique angle with respect to a central axis of the associated shaft. Each cutting blade includes a central body having a plurality of teeth radially spaced thereabout. The apparatus further includes a conveying device fluidly coupled to the shafts such that materials cut by the cutting blades are conveyable in a downstream direction by the conveying device.

Abstract: A reliable, inexpensive option for the plates that function as wear parts and are mounted on an inner face of a casting wall of a stator. To achieve this the plates are designed as cast parts and are fixed to the inner face of the casting wall from an exterior of the stator. The plates are fixed by fixing bolts, which are screwed into the plates through the casting wall from the exterior. The plates have transverse threaded bores that correspond to the bolts. Respective spacer rings are pushed onto the fixing bolts secured by wedge-shaped cotters in both a positive and non-positive fit, and the wedge-shaped cotter pressing on the spacer rings that lie against the outer face of the casting wall. This invention is extremely economical and improves the operational safety in comparison to known options.

Abstract: The invention relates to a cutter wheel for granulating strands of plastic material, said cutter wheel being composed of a plurality of jointlessly juxtaposed wheel portions with individual cutter portions and having axially extending teeth, said teeth forming a continuous cutting edge. The teeth of the cutter portions merge into each other and have such an alternating inclination with respect to the axis of the cutter wheel that there result continuously extending zigzag-shaped cutting edges over the entire cutter wheel.

Abstract: A refiner plate carrier for use in refining lignocellulosic material including a mounting mechanism for mounting to a refiner plate segment and not a rotor or stator disk. The combined plate carrier and refiner plate segment may be then attached to a refiner disk. The refiner plate carrier need not provide structural support to the segment during lignocellulosic refining.

Abstract: The present invention relates generally to cutting blades for shredders. Specifically, this invention teaches cutting blades and a rotary cutting assembly which reduce the power needed to shred paper, plastic, and other forms of media that hold information. This is accomplished by creating a cutting blade with at least three adjacent teeth. The formation of three or more adjacent teeth more readily tears through paper and other media thus reducing the amount of power necessary to drive a shredder.

Abstract: A blade for a comminution machine includes a first attack face facing in a first direction to perform comminution when the blade is rotated about an axis of rotation in a first direction. The blade also includes a second attack face facing in a second direction to perform comminution when the blade is rotated about the axis of rotation in a second direction substantially opposite to the first direction. A radial exterior of the first attack face and a radial exterior of the second attack face are connected along an arc subtending at least 30 degrees and less than 110 degrees with respect to the axis of rotation.

Abstract: A shredder blade for cross cutting material fed into a shredder and method of manufacturing same.

Abstract: A cutter assembly for a rotary, shear-type shredder including a cutting-tool carrier having a body possessing a rotational axis, a shear cutting tool, and a generally radial, sliding-friction-type, heat-cycle, binding interface removably anchoring the tool to the carrier body. This assembly is made by (a) forming a projection on one of the tool and the carrier, (b) forming a generally complementary, projection-receiving void space in the other of the tool and the carrier, whereby the projection and the void space nominally have an interference-fit relationship relative to one another, (c) creating a temperature differential between the tool and the carrier to an extent producing a clearance-fit relationship therebetween, (d) following that creating, fitting the projection snugly inside the void space, (e) reducing the created temperature differential toward zero, and (f) thereby establishing a robust, linear-sliding-friction anchoring interface between the tool and the carrier.

Abstract: A paper shredder cutting tool having multiple cutting edges (-) constructed from a pair of cylindrical rotary cutters, which are each separately mounted on a polygonal shaft, and a plurality of cutting blades are securely mounted on the shafts. A paper guide is configured between each pair of adjacent cutting blades, thus partitioning the cutting blades therebetween, and thereby allowing the cutting blades to be assembled and mounted in an interleaving fashion on the two cylindrical rotary cutters. Moreover, each of the cutting blades is further constructed from a pair of blades. Having a plurality of cutting edges circumferentially arranged and minimally separated on each of the pair of blades, thereby forming a compact assembly of blade edges. The paper shredder cutting tool provides capability to feed around tens sheets of paper or cardboard at one time, thereupon being rapidly shredded into small bits.

Abstract: An annular casing for the press rollers of roller presses for the pressure comminution of particulate material, the outer surface of which casing always has a high degree of hardness and consequently a high wear-resisting capability, but the radially inner region of which casing has a lower degree of hardness to avoid casing ruptures, it is proposed according to the invention that the material of the casing consists of nodular cast iron with at least the alloying elements Ni and Mo and with a bainitic structure with residual austenite, and in that, to achieve a self-hardening surface, the boundary layer of the annular casing—contains martensite, which is constantly renewed by external pressure loading of the casing surface when the press roller is in operation.

Abstract: Blade pairs for a paper shredder comprises two single blades with a flange rib on the surface of each blade, and the flange ribs of two single blades are against each other when shredding the paper. A hole is in the center of each blade. 2-8 corresponding blade points are arranged at the edge of each blade, which slant a certain degree beyond the plane of the blades, and the blade points of each blade pairs meet at a certain angle when assembled. Blade pairs is processed easily and it can save raw material.

Abstract: The present invention relates to a round undulating blade for shredder, where a sheet metal is integrally formed into a round undulating blade to serve as the blades for constructing a blade module. The blade includes: a periphery; an undulating blade flank including at least two cambers having a first curvature and at least two cambers having a second curvature alternatively arranged with respect to the cambers having the first curvature; and hooked edges formed on the periphery of the cambers having the first curvature, wherein the undulating blade flank of the blade serves to cut paper along a longitudinal direction to form paper strips having double-tapering end, and the hooked edges serve to cut the strips along a horizontal direction into paper chips. These characteristics help to reduce the manufacturing cost, reduce the motor load and power consumption, to thereby enhance the market competitiveness.

Abstract: A tooling assembly 10 having a first set of blades which are formed from a first material and a second set of blades which are formed from a second material. More particularly, each carbide blade of each member 62, 64, 66, and 68 is operatively disposed between two steel blades.

Abstract: A granulator has a first coarse cutting stage operating at between 5 and 45 rotations per minute and a second fine cutting stage operating at two to ten times the speed of the first stage. Since granulate exiting the second stage is uniformly divided, the granulator operates independent of a screen. A first cutter stage has cutting segments having blades interspersed with deflector segments about a shaft. Rotation of the shaft urges the blades past a spaced stationary cutter.

Abstract: A blade for a paper shredder cutting tool that includes an improved structure for one of two blades of each cutter of two rotary cutters of a paper shredder cutting tool. A protruding ring protrudes from a rim of a center hole of the blade, and the protruding ring and the blade are formed as an integrated body. The protruding rings not only enable disposition of paper chaff guides, but also will not deform because of thermal expansion and contraction when shredding paper, thereby preventing a gap from forming between the two blades, and thus the occurrence of paper jamming or wedging together of the blades of the upper and lower cutters.