Abstract: A method for manufacturing a sintered component includes a step of making a green compact having a relative density of at least 88% by compression-molding a base powder containing a metal powder into a metallic die, a step of machining a groove part having a groove width of 1.0 mm or less in the green compact by processing groove with a cutting tool, and a step of sintering the green compact in which the groove part is formed after the step of forming the groove part.

Abstract: According to one embodiment, a cooling device includes a heat releasing element including a surface configured to contact a heat generating element and an internal fluid channel configured to flow a cooling medium. The cooling device also includes a plurality of cooling fins within the fluid channel, each of which extends in a direction crossing a flow direction of the cooling medium and has a zigzag, corrugated shape defined by multiple bent portions.

Abstract: The invention relates to a method for producing a flow plate (10a; 10b) for a fuel cell, in particular a PEM fuel cell, and/or an electrolyzer, wherein the flow plate (10a; 10b) is provided with at least one flow element (12a; 12b), which is at least partially made of metal fibers (14a; 14b). According to the invention, in at least one method step, the metal fibers (14a; 14b) are aligned by means of at least one alignment unit (30a; 30b).

Abstract: A corrugated fin heat exchanger includes: a first flat tube; a second flat tube aligned in parallel with the first flat tube; and a corrugated fin disposed between the first flat tube and the second flat tube, and the corrugated fin includes a first slant portion bridging between the first flat tube and the second flat tube and inclined relative to a perpendicular line toward the first flat tube at a first angle of inclination, a second slant portion bridging between the first flat tube and the second flat tube and inclined relative to the perpendicular line at a second angle of inclination, and a third slant portion bridging between the first flat tube and the second flat tube, the third slant portion positioned between the first slant portion and the second slant portion, and inclined relative to the perpendicular line at an angle of inclination larger than both of the first angle of inclination and the second angle of inclination.

Abstract: An air fin for a heat exchanger has air channels defined by corrugations, the corrugations having generally planar flanks joined by alternating crests and troughs. Perforations extend through portions of at least some of the flanks and are aligned within two spaced apart planes. A rectangular aperture extends through at least two consecutive ones of the corrugations, and is bounded by the two planes. A method of making the air fin includes forming perforations into a continuous strip of metal sheet at regular intervals, corrugating the strip to form crests and troughs between the perforations, and punching out a portion of the strip at regular intervals. The punching out includes shearing webs between the perforations, and results in the formation of the rectangular aperture.

Abstract: The invention relates to a method for manufacturing an acoustic absorbent panel, comprising the following steps: provision of a sheet of plastic material, formation of a plurality of through-slots in the sheet by milling using at least one milling tool. The invention makes it possible to manufacture an acoustic absorbent panel quickly and inexpensively.

Abstract: To produce closure elements for metal touch-and-close fasteners in a metal carrier (3), notches (13) corresponding to the outlines of hook elements (1) are made, while leaving a connecting line for each notch. Bending operations are carried out to raise the regions delimited by the notches (13) out of the plane of the carrier (3) as hooking elements (1) around the connecting lines serving as bending lines. The carrier (3) is guided through the region (5) of the tooth engagement between rotational bodies (7, 9) having peripheral teeth. The tooth shapes of the rotational bodies (7, 9) and the type of the tooth engagement are selected such that the tooth engagement cuts the notches (13) and stamps the metal carrier the bending operations.

Abstract: A method for producing expanded metal profiles, consisting of subjecting a metal strip of width less than the development of the profile to be produced to the following operations: —forming longitudinal slits in at least that longitudinal band which is to form the central web of the profile, —bending the edges of the slits, —profiling said strip, —transversely stretching that band containing the slits, —pressing areas of said central web in correspondence with said stretched band to displace them external to the plane of said web, characterised by subjecting the bent edges to drawing to obtain radiused edging having the tangent to the free edge forming an angle not less than 90° to the surface of the strip.

Abstract: A method and device for manufacturing of electrical components on a continuous web or discrete sheets of dielectric material are disclosed. The method includes feeding, from a supply roll of a laminated web or a supply of sheets including at least one unbroken layer of conducting material laminated on a flexible backing layer of dielectrical material, the laminated web or discrete sheets to a nip between a patterned cylinder and a cooperating cylinder, to shape the conducting layer into a repeated pattern of conducting material having ridges and valleys. The method further includes removing, by mechanical machining, conducting material from the thus shaped conducting layer. The removing is performed simultaneously with the step to shape the conducting layer, and by way of the cooperating cylinder, designed as a milling cutter cylinder.

Abstract: A method of manufacturing serpentine fins for assembly between tubes in a heat exchanger core. The method includes providing a flat metal strip and forming in the strip, multiple rows of split louvers. Each row of split louvers has louvers formed in pairs of adjacent, spaced louver banks extending across the width of the strip. Each row includes ribs formed in the strip parallel to the louver openings and extending across the pair of louver banks. The metal strip has unformed portions extending across the strip width between rows of split louvers for forming folds across the width of the strip. After forming the rows of split louvers, pressure is applied to the strip to cause the flat strip to buckle along the unformed portions forming folds in the strip resulting in the serpentine fin. Preferably, the strip has ribs formed both in the center portion and along the edges.

Abstract: The present invention provides a planographic printing plate manufacturing apparatus comprising: a cutting process section which cuts a web in a thickness direction of the web by pinching the web with at least a pair of an upper knife and a lower knife, wherein the lower knife includes a flat part supporting a center of the web, a decline part gradually declined an upper end toward outside from the flat part and a cutting edge part having an upper end gradually raised toward outside from the decline part to be a cutting edge, an angle of the lower knife at a boundary point between the decline part and the flat part is 135° or more, a boundary point between the decline part and the cutting edge part is provided so as to be greater or equal to a droop width of a lower surface of a cut product.

Abstract: Expanded metal machine includes a stationary knife and an adjustable knife which is adjustable in a vertical direction and a transverse direction. The adjustable knife includes a cutting edge with spaced-apart cutting projections in the transverse direction. A transport device for transporting a flat material in a direction of transport between the knives is provided. A cam is provided and configured for performing a periodic vertical motion. There is a transverse adjustment device configured for adjusting the transverse motion of the adjustable knife in a manner synchronized with the traveling motion. Likewise, there is an eccentric drive provided for the cam, and that is configured for guiding the cam in a circulatory motion which runs in a plane determined (e.g., bounded) by the vertical direction and the transverse direction.

Abstract: The invention provides a sheet metal joint and a method for forming a sheet metal joint. The sheet metal joint includes first and second metal sheets disposed in a parallel relation to one another. Each of the first and second metal sheets has a plurality of perforations with a tang extending from each perforation. The tangs of the second sheet and the tangs of the second metal sheet are curled together in opposite rotational directions. The tangs of the first metal sheet space the first and second metal sheets from one another and the tangs of the second metal sheet substantially fixedly engage the first and second metal sheets with respect to one another.

Abstract: The tension device comprises: a feeding unit for feeding a band-shaped metal plate to a press unit; and a holding unit for applying tension to the band-shaped metal plate. The feeding unit is constituted by a moving member and a feeding pin. The front end of the feeding pin has a slope face so as to engage with a collared through-hole of the band-shaped metal plate when the moving member moves in a feeding direction of the band-shaped metal plate and so as to disengage therefrom when the moving member stops and moves in the reverse direction. The holding unit has a holding member, which holds and applies prescribed tension to the band-shaped metal plate when the moving member stops and which releases the band-shaped metal plate when the moving member starts to move in the feeding direction.

Abstract: A corrugated fin cutting method includes continuously conveying a fin material formed into a corrugated shape having a plurality of ridge sections and a plurality of valley sections while regulating a number of the ridge sections and positioning the valley sections; and cutting the fin material at a bottom portion of one of the valley sections between a stationary blade member and a rotating blade member as the rotating blade member rotates in one direction with respect to the stationary blade member while the fin material is being conveyed.

Abstract: A wire-grid metal sheet includes a grid portion defined by a plurality of spaced strip-shaped longitudinal members extending longitudinally and cross members extending substantially perpendicular to the longitudinal members. A wire grid is made by attaching the wire-grid metal sheet to a frame. The cross members are arranged at intervals at least about five times greater than those of the longitudinal members. The longitudinal members and the cross members may define a lattice pattern. Alternatively, the longitudinal members or the cross members may be arranged in a staggered manner.

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 and which may be used to perform a cutting operation.

Abstract: A serpentine fin for assembly between tubes in a heat exchanger core, and a method of making same from a metal strip. The strip edges have a hem comprising a double thickness of the strip material extending inward from the edge. The metal strip has folds extending across the strip width such that the strip forms a serpentine shape, with the folds being adapted to contact the tubes in the heat exchanger core. Multiple rows of split louvers are disposed between adjacent folds. Each row of split louvers comprises louvers having openings extending in the direction of the strip length and formed in a pair of adjacent, spaced louver banks. Ribs are disposed parallel to the louver openings adjacent the strip edges and in at least one center portion of the strip between the strip edges, and extend across the pair of louver banks.

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 rotary apparatus having a first rotating die assembly and a second rotating die assembly arranged in juxtaposition with one another on respective first and second sides of a strip work piece movement path, and operable in unison together to perform operations on a work piece passing therebetween, each die assembly having a main rotor mounted for rotation, at least one die support body supported by the main rotor, and being swingable relative to the main rotor, control cams connected the die support body, cam guides engageable by the control cams, and die support body bearings mounted on the main rotor for carrying the die support body. The die support body can be self-adjusting to the linear speed on the work piece, before and after contact. The die can have a movable portion which moves in or out to provide selective operation on the workpiece. The main rotors are connected by a gear drive train with anti-backlash adjustment.

Abstract: The invention provides a method of making a three-dimensional metal structure, the method being characterized by the following steps: making longitudinal cuts in a sheet metal strip by causing the strip to pass between two rollers carrying annular knives whose blades are discontinuous and angularly offset from one roller to the other so as to form parallel rectilinear chords that are interconnected at regular intervals by connecting bridges and by linking legs, two adjacent chords being provided either with U-shaped bridges for connection with two legs of the same orientation, or with S-shaped bridges for connection with two legs of opposite orientations, and the U-shaped bridges are oriented in opposite directions from one chord to the next; slicing the strip transversely by sectioning said chords and said bridges at different longitudinal positions; moving every other precut chord into an offset plane by exerting vertical thrust on the chords carrying the U-shaped bridges so as to cause the legs to pivot

Abstract: A portable metal stud punching system has an alignment frame with an infeed alignment port in a first side and an outfeed alignment port in an opposite side. There is a punch and die positioned within the alignment frame. A length of metal stud is inserted through the infeed alignment port with one vertical side of the metal stud disposed between the punch and the die. A first hydraulic unit is attached to the punch and moves a first direction thereby inserting the punch into the die and punching a tab out of the vertical side of the metal stud. A second hydraulic unit moves the punch assembly in a direction perpendicular to the first direction of the first hydraulic unit. After the tab has been punched, the second hydraulic unit advances the metal stud by sliding the punch assembly a distance equal to the desired space between tabs. The punch is retracted by the first hydraulic unit and the punch assembly is returned to its original position by the second hydraulic unit.

Abstract: A heat exchanger comprising at least one row of flattened tubes through which a heat exchange medium may pass. A serpentine fin 10 disposed between adjacent flattened tubes has relatively straight segments that are connected by bend radii 20. The fin 50 defines a plurality of louvers 32 therein. Each louver 32 forms an elongated slit that extends at least partially into the bend radii 20, through which a fluid to be heated or cooled by the medium may pass. The fin 50 is formed by a tool with fin blades that have tips that are configured to form the extended length louver that protracts into the bend radius that separates adjacent convolutions.

Abstract: The present invention relates to a device comprising rotary cutting tools for combining cutting and shaping operations on metal sheets, the density of the cuts preferably being very high, said cutting operations preferably being integrated into an automated shaping line, characterised in that it comprises a first pair of rotary cutting tools (1, 2) producing a first set of cuts (7, 7′, 7″) and a second pair of rotary cutting tools (3, 4) completing and finishing off the first cuts by a second set of cuts or by a fold (8) in order to obtain a final closed cut with the drop of cut waste or a puncture, respectively

Abstract: The present invention relates to a method of and a system for carrying out at least one operation on at least one wire(1) in a wire forming manufacturing machine, said operation involving deformation of at least a part of the wire, said machine comprising at least two counter-rotating synchronized blocks(2,4), said blocks each comprising at least one operation means(6,7) for performing said operation.

Abstract: Concave portions and convex portions are formed on a peripheral surface of a thin metal sheet by applying a pressing force thereto while the metal sheet is being embossed; pores are each formed on an apex of each of the concave portions and convex portions and burrs each projecting outward from a peripheral edge of each of the pores are generated by the pressing force; the metal sheets having the concave portions and convex portions formed thereon are layered on each other; the burr at the apex of each convex portion of a lower-layer metal sheet is interlocked with the burr at the apex of each concave portion of an upper-layer metal sheet adjacent to the lower-layer metal sheet to integrate the metal sheets with each other; and an active substance is charged into spaces between the upper-layer metal sheet and the lower-layer metal sheet through an aperture at the apex of each of the concave portions and convex portions.

Abstract: A tool and its finishing method of surface for center fin member of an air conditioning apparatus for a vehicle. The tool includes a plurality of fin blades each having a circular cutter shape and being provided at a periphery thereof with a plurality of cutting teeth and at a central portion thereof with a central hole. The fin blades are stacked on one another in such a fashion that the central holes are aligned together, and a pair of jig discs are arranged in a coaxial and integral fashion with the fin blades. The tool serves to form louvered center fins having a plurality of continued flat wall portions formed by bending a thin strip in a desired pitch in a zig-zag fashion, each of the flat wall portions having a plurality of louvers extending in perpendicular to the flat wall portion.

Abstract: An improved air center form roll for use in combination with a like form roll to produce an accordion-like folded fin for a heat exchanger core, the form roll being of the type comprising a plurality of form discs abutted one to the other and having a plurality of star-like teeth thereabout. Points of the star-like teeth define a major diameter of the form roll and valleys between adjacent ones of the star-like teeth define a minor diameter of the form roll. The form roll further includes at least one stripper disc having no teeth therearound and interposed between at least two of the plurality of form discs wherein the stripper disc has a diameter less than the minor diameter of the form roll. The improvement to the form roll comprises a modified disc having a plurality of modified star-like teeth thereabout. The modified disc is interposed at each abutment between the stripper disc and one of the abutting form discs.

Abstract: The present invention relates to a method of and a system for carrying out at least one operation on at least one wire (1) in a wire forming manufacturing machine, said operation involving deformation of at least a part of the wire, said machine comprising at least two counter-rotating synchronised blocks (2,4), said blocks each comprising at least one operation means (6,7) for performing said operation.

Abstract: Slow production speeds in the manufacture of lanced and offset fins for use in heat exchanger tubes are eliminated through the use of a method of forming the fins involving a plurality of roll assemblies located along a forming path which may operate on a strip of fin forming material of indeterminate length. After being formed, the fin may be cut to any desired length.

Abstract: Slow production speeds in the manufacture of lanced and offset fins for use in heat exchanger tubes are eliminated through the use of a method of forming the fins involving a plurality of roll assemblies located along a forming path which may operate on a strip of fin forming material of indeterminate length. After being formed, the fin may be cut to any desired length.

Abstract: A tube and turbulator and method of making the same for a heat exchanger including a base, a top spaced from and opposing the base, a first side interposed between the base and the top along one side thereof, and a second side interposed between the base and the top along another side thereof. The base, top, first side and second side form a channel. The second side is triple hemmed such that ends of the base and the top are disposed within the channel. A flat turbulator may be disposed inside the tube and includes a base extending laterally and longitudinally in a strip. The flat turbulator also includes a plurality of corrugations spaced laterally along the base and extending longitudinally and generally perpendicular to the base in an alternating manner. The corrugations are rolled in a direction parallel to a longitudinal axis of the strip.

Abstract: Concave portions and convex portions are formed on a peripheral surface of a thin metal sheet by applying a pressing force thereto while the metal sheet is being embossed; pores are each formed on an apex of each of the concave portions and convex portions and burrs each projecting outward from a peripheral edge of each of the pores are generated by the pressing force; the metal sheets having the concave portions and convex portions formed thereon are layered on each other; the burr at the apex of each convex portion of a lower-layer metal sheet is interlocked with the burr at the apex of each concave portion of an upper-layer metal sheet adjacent to the lower-layer metal sheet to integrate the metal sheets with each other; and an active substance is charged into spaces between the upper-layer metal sheet and the lower-layer metal sheet through an aperture at the apex of each of the concave portions and convex portions.

Abstract: A plurality of louvers are formed symmetrically on the two sides of the width-direction central portion of the inclined portion of a corrugated fin, and include, one-side louvers, which are formed integrally in one and the other ends of the central portion, are formed so as to project from one and the other ends of the central portion toward the advancing direction of the corrugated fin and louvers, which are formed on one and the other sides of the central portion, which are formed on one and the other sides of the central portion, are formed inclined on the same sides as the one-side louvers that are formed on one and the other ends of the central portion.

Abstract: A method of manufacturing interlocking sheet metal floor members for use in a grain storage bin or like application requiring passage of fluid through the floor members without permitting passage of granular material therethrough. The method comprises the steps of forming a first interlocking section on a first side edge of a strip of sheet metal and a second interlocking section on a second side of the strip of sheet metal; shearing, opening and corrugating the strip of sheet metal in one roll forming stand which utilizes a pair of shearing and corrugation rollers, wherein the shearing step includes shearing rows of slits across a width of a central portion of the strip of sheet metal, wherein the opening step includes opening the slits to permit fluid flow therethrough, and wherein the corrugating step includes corrugating the strip of sheet metal along each of the series of the slits; and cutting the strip of sheet metal at selected transverse locations to form the sheet metal floor members.

Abstract: Forming machine for metal strips, in particular for the manufacture of plates for electric accumulators, comprising moving means (2, 3) designed to convey a continuous strip (10) through an incision zone (8) associated with forming means (7) provided with a plurality of teeth (9) operationally actuated by actuator means (11) so as to make incisions in the strip (10) so as to form a continuous mesh (12). The actuator means (11) move the forming means (7) in accordance with a law of motion having a component oriented in the direction of feeding (A) of the strip (10) and a component oriented in a direction (B) substantially perpendicular to the direction of feeding (A) of the strip (10). The first component allows the teeth (9) to advance substantially in synchronism with the strip (10), while the second component allows the teeth (9) to make incisions in and expand the strip (10) during an incision step of the machine (1). For this purpose, the strip is fed continuously by the moving means (2, 3).

Abstract: A method and apparatus are provided for roll forming a plurality of fin strips (10) from a single elongated strip of sheet material (20). The strip (20) includes a pair of adjacent, longitudinal rows (22, 24) of alternating crests (26) and valleys (28), with the crests (26) and valleys (28) of the row (22) longitudinally offset from the crests (26) and valleys (28) of the other row (24) so that the two rows (22, 24) are joined by a plurality of longitudinally spaced discrete connections (30) that define a longitudinal interface (32) between the two rows (22, 24). The connections (30) are broken by displacing the two rows (22, 24) relative to each other to form a pair of fin strips (36, 38), with each fin strip (36, 38) having a side edge (40, 42) defined by the now separated interface (32).

Abstract: In order to improve a bending center comprising a bending unit, a loading device with a feed table for receiving a sheet-metal part to be inserted, and a manipulator arrangement, with which the sheet-metal part can be gripped, moved as well as rotated, in such a manner that handling of the sheet-metal part is as error-free as possible with loading times which are as short as possible it is suggested that the loading device have a sensor, with which the position of the sheet-metal part relative to a defined insertion position into the bending unit can be determined, and that the loading device have a control which controls the manipulator arrangement handling the sheet-metal part with respect to the movement in the first and second directions as well as the rotation about the axis of rotation on the basis of the position of the sheet-metal part determined by the sensor in such a manner that the manipulator arrangement inserts the sheet-metal part into the bending unit in the exactly defined insertion position.

Abstract: An apparatus for gripping, guiding and transporting opposite longitudinal side edges of slit, deformable strip for forming expanded mesh sheet. One chain of each of two pairs of opposed endless chains has a longitudinal recess adjacent a longitudinal planar side edge of the strip for receiving the planar edge of the strip therein and the opposed chain of each of said pairs has a plurality of equispaced sharp projections for penetrating the longitudinal planar side edge of the strip whereby the said edge is effectively gripped between the opposed chains during expansion.

Abstract: Procedure and apparatus for the optimized manufacture of coil springs on automatic spring winding machines. It is the object of the present invention to offer both a procedure and an apparatus by which even in case of fluctuating values of the wire parameters high accuracies during the spring manufacture are guaranteed and simultaneously the scrap is minimized. The solution to this problem is that prior to the winding the wire parameters are determined and the measuring results are used directly for the adjustment of the position of the winding pins or winding rollers and/or the pitch wedge, and that the wire between the uncoiling device and the guiding assembly forms a loop whereby the lateral deflection of this wire loop is measured by a recognition unit and the uncoiling device carries out an additional movement controlled by the recognition unit.

Abstract: A two stage die set for sequentially blanking an opening in a work piece, and thereafter forming edges of the work piece around the opening and having a male die assembly, having a male blanking die, a male forming die spaced from the male blanking die, and a recess therebetween, a female die assembly having a generally hollow female die sleeve, the die sleeves being shaped and dimensioned to correspond to the shape of the male blanking die and to receive it in telescopic relation, a moveable support plate located around the female die sleeve the moveable plate being biassed so as to urge it into a first extended position, and the moveable plate yielding to the male forming die of the male die assembly, when the male and female dies are closed together, so that the male blanking die, in co-operation with the female die sleeve blanks out a portion of a work piece and forms an opening, and upon further relative movement between the male and female dies towards one another, the male forming die co-operates with

Abstract: A roll forming tool for manufacturing louvered serpentine fins. The tool has a plurality of fin blades each having a predetermined size and shape. Each of the blades has a plurality of cutting edges for forming scallops in a serpentine fin such that a louvered serpentine fin is formed. The blade forms the louvers in the fins that create a turbulent air flow and thus increase the rate of heat exchange in a heat exchanger.

Abstract: A process for manufacturing razor blades from a continuous strip of metal stock by stamping a plurality of openings in the strip for precise registry of the blade edge when employed in the razor and then running the stock through a device which partially slits the strip along lines which are precisely located with respect to the edges of the stock and the openings. The strip is then heat treated after which it is run through a device which splits the stock along the previously slit lines to form a plurality of continuous strands containing interconnected blades disposed end to end.

Abstract: A method and apparatus for forming a strip of fins with louvers comprising providing fin forming rolls comprising stacked carbide plates having rolling and cutting edges forming fins with louvers, and directing a strip of clad aluminum between an opposed pair of fin forming rolls. The carbide plates are preferably made of carbide containing tungsten, cobalt and carbon, wherein the major constituent is tungsten.

Abstract: A device for measuring an angle in a workpiece piece which includes a base; a pair of feelers which are movable relative to the base and each of which has an active surface for contacting a respective portion of the workpiece piece during the measurement; a thrust mechanism for bringing the active surfaces of said feelers into contact with the respective portions of the workpiece piece being measured; and a sensor mechanism for detecting the positions of the feelers relative to the base.

Abstract: A tube traveler and slitter for extracting a tube from a heat exchanger tubesheet and slitting the tube longitudinally into two segments includes two spaced apart deforming rolls having a nip between the peripheries defining a passageway. The periphery of each roll is serrated and has a cylindrical central portion of a larger diameter than the remainder of the periphery, and a cylindrical portion spaced from the central portion at each end of the roller, a truncated conical surface being between the cylindrical portions. The rollers extract and deform the tube into a configuration having a flattened central portion and a bulbous configuration at each edge. A rotary slitter blade is positioned for engaging and slitting each edge longitudinally. The axis of rotation of the slitter blades is downstream from the axes of rotation of the rolls.

Abstract: A tube traveler and slitter for extracting a tube from a heat exchanger tubesheet and slitting the tube longitudinally into two segments includes two spaced apart deforming rolls having a nip between the peripheries defining a passageway. The periphery of each roll is serrated and has a cylindrical central portion of a larger diameter than the remainder of the periphery, and a cylindrical portion spaced from the central portion at each end of the roller, a truncated conical surface being between the cylindrical portions. The rollers extract and deform the tube into a configuration having a flattened central portion and a bulbous configuration at each edge. A rotary slitter blade is positioned for engaging and slitting each edge longitudinally. The axis of rotation of the slitter blades is downstream from the axes of rotation of the rolls.

Abstract: Forming rollers having a tooth tip concave portion at the tip of a tooth tip portion, a tooth bottom convex portion at a bottom of a tooth bottom portion and louver cutter at an oblique line portion between the tooth tip portion and the tooth bottom portion. A radius of an arc-shaped portion of the tooth tip concave portion at front side of rotational direction is set to be larger than a radius of an arc-shaped portion of the tooth tip concave portion at a rear side of the rotational direction. A radius of an apex portion of the tooth tip portion at the front side is set to be smaller than a radius of an apex portion of the tooth tip portion at the rear side and louver cutter at the oblique line portion is formed to have a predetermined interval from the apex portions of tooth tip portion. Therefore, flat folded portions having substantially the same curvature at both shoulder portions thereof horizontal are formed.

Abstract: In a method of forming expanded metal mesh from a deformable strip which includes the steps of preforming and slitting the strip by intermeshing tooth segments of at least an upper disk and a lower disk with the strip passing therebetween, wherein the tooth segments each include linear leading and trailing surfaces joined at an apex defining a nose angle, and intersecting respective tangents to a radius of the disk at circumferentially spaced locations defining entry and exit angles, respectively, an improvement which includes selecting the exit angle in accordance with the formula: ##EQU1## where R=radius of tooth root;D=depth of tooth; andT=strip thickness.

Abstract: A fiber for reinforcing concrete is manufactured from wire or flat bands and has a linear center section and a first intermediate section connected to the first end of the center section and a second intermediate section connected to the second end of the center section. The first and the second intermediate sections have a wavy shape and are shorter than the center section. A first end section is connected to the first intermediate section and a second end section is connected to the second intermediate section. The first and the second intermediate sections preferably have an elongated S-shaped deformation extending in a common plane. The first and the second end sections are substantially linear and extend parallel displaced to the center section. The fibers are produced in one stamping operation in an inexpensive manner.