Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
  • B26F—PERFORATING; PUNCHING; CUTTING-OUT; STAMPING-OUT; SEVERING BY MEANS OTHER THAN CUTTING
  • B26F3/00—Severing by means other than cutting; Apparatus therefor
  • B26F3/002—Precutting and tensioning or breaking
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
  • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
  • H01F41/0206—Manufacturing of magnetic cores by mechanical means
  • H01F41/0213—Manufacturing of magnetic circuits made from strip(s) or ribbon(s)
  • H01F41/0226—Manufacturing of magnetic circuits made from strip(s) or ribbon(s) from amorphous ribbons

Definitions

• the present invention relates to amorphous metals and, more particularly, to a method and apparatus for slitting an amorphous metal foil.
• Amorphous metals are metal alloys in which the usual crystalline structure is not present.
• a resume of amorphous metal materials and their properties is contained in a paper entitled METALLIC GLASSES: A MAGNETIC ALTERNATIVE, by Donald Raskin and Lance A. Davis, published in IEEE Spectrum, November 1981, the contents of which are herein incorporated by reference.
• an amorphous metal is formed by cooling a molten alloy at such a high rate (typically exceeding a million degrees per second) that the usual crystalline structure of the metal does not have time to form. Instead, the metal is frozen into a metastable condition in which the disorder of the molten form is preserved.
• Amorphous metals exhibit a number of differences in their properties from the normal crystalline form of the same alloy which make them especially suitable for certain applications. They are harder, more abrasive and more sensitive to mechanical stresses, have higher mechanical strength, flexibility and electrical resistivity than their crystalline forms and some alloys of amorphous metal exhibit the softest magnetic characteristics of any known materials. This latter property Is especially desirable for magnetic core materials since the ease with which a magnetic material is magnetized and demagnetized controls the hysteresis losses experienced when the magnetic material is repetitively magnetized first in one direction and then in the other direction as is customarily the case for magnetic core materials in AC machinery.
• An AC distribution transformer for example, has its primary winding permanently connected to the AC line.
• the primary winding continuously cycles the transformer core between extremes of magnetic intensity.
• the repetitive traversing of the hysteresis loop of the transformer core produces hysteresis losses which must be made up by primary power.
• These hysteresis losses represent an overhead cost of operating the transformer which is independent of load. Even during periods of light or zero secondary loading, power must be fed to the primary to supply the hysteresis losses in the transformer core.
• Substitution of a suitable amorphous metal for the magnetic steel normally used in transformer cores can reduce this hysteresis overhead by a factor of 4 or more.
• Amorphous metals also have characteristics which have heretofore interfered with their use.
• One of the problems in amorphous metals made by the above-referenced process arises because the need for an extremely rapid cooling rate during the casting of a strip of amorphous metal dictates that the amorphous metal strip must be extremely thin. Thicknesses of about 0.076 mm are about the maximum which can be produced, with more typical values on the order of from about 0.025 to about 0.05 mm.
• Normal transformer core laminations are about ten times thicker. Thus, about ten times as many layers of amorphous metal are required to form a transformer core of the same cross section as are required with the steel laminations of the prior art.
• Space factor is important in many magnetic cores.
• Space factor is defined as the ratio of the actual volume of core material to the physical volume consumed by the core. If the layers making up the core do not lie flat upon each other but instead remain separated by air or other non-magnetic material, the physical volume consumed by the core increases without a corresponding increase in magnetic properties. If burrs or irregularities are present on the edges or surfaces of the core laminations, the laminations do not lie flat and consequently the space factor is degraded. The thinness dictated by the way amorphous metals are made adds to the problem. For example, edge burrs and/or surface irregularities which are small enough to be ignored on the edges of conventional core laminations may cause severe degradation in the space factor when ten or more times as many layer are used.
• Amorphous materials are so hard and abrasive that it is extremely difficult to cut the as-cast strip into the sizes and shapes needed to form a core.
• Conventional cutting techniques include, for example, slitting with rotary shearing devices, scissors-type cutters and pinch-type cutters, all of which rely on sharp cutting edges for clean cuts.
• the required sharp cutting edges of these devices rapidly degrade due to the hard abrasive material being cut, eves when the cutting edges are made of hard materials such as, for example, an appropriate tungsten carbide.
• Wheel-type slitting devices also suffer from the thinness of the amorphous metal strip.
• the cutting wheels must be set for a clearance on the order of 0.0051 mm or less.
• Such tolerances call for the best, and most expensive, attainable tolerances and, even when such tolerances are attained, the cutting must be performed under controlled temperature conditions.
• the cutting edges wear, they begin to produce kerfs or burrs which prevent successive layers of a core from laying in complete contact with each other and thus result in degraded space factor.
• patents 4,328,411 and 4, 356, 377 disclose laser and/or electron beam cutting techniques for forming complex shapes by either vaporizing and cutting completely through an amorphous strip or heating it above its crystallization temperature so that the desired cutting line assumes the brittle crystalline form of the alloy which can thereafter be easily broken to separate the desired shape from the remainder of the strip.
• these techniques avoid the degradation in edge quality resulting from worn cutting edges of cutting tools, they still produce reduced space factor due to edge burrs.
• the heating that these techniques produce along the cutting line leaves crystallized alloy with a resulting degradation of the magnetic properties in these areas which use of the amorphous material is intended to provide.
• An object of the invention is to provide a method and apparatus for cutting strips of brittle and very hard amorphous alloy that is characterized by clean, burr-free edges without the production of crystallized alloy at the edges.
• Another object of the invention is to provide a method and apparatus for cutting strips of amorphous metal which takes advantage of the characteristics of the amorphous metal itself to produce the cut.
• a further object of the invention is to provide a method and apparatus for cutting strips of amorphous metal of unlimited length.
• a still further object of the invention is to provide a method and apparatus for cutting a strip of amorphous metal into two strips along a cutting line which is defined by a scribe line on the strip.
• a yet further object of the invention is to provide a method and apparatus for cutting a strip of amorphous metal into two strips along a line of indefinite length without requiring special environmental control.
• a method for slitting a strip of amorphous metal comprising scribing a line in a first surface of the strip, folding opposed sides of the strip toward each other along the line to form a folded strip having the line within the fold and defining an apex of the fold, creasing the fold and at least partially flattening the folded strip whereby the strip separates into first and second strips on opposed sides of the line. Apparatus for executing this method is also provided.
• a method for slitting a strip of amorphous metal comprising backing up a first surface of the strip with a hard unyielding back-up surface, drawing a cutting edge of a wheel-type scribing tool along a cutting line on a second surface of the strip, applying a scribing force on the wheel-type scribing tool effective to compress a line of the amorphous metal beneath a cutting edge of the wheel-type scribing tool to thereby form a depressed scribed line, spacing first and second parallel surfaces of first and second mandrels a predetermined distance apart, folding first and second edges of the strip toward each other with the scribed line enclosed therebetween, drawing the strip between the first and second parallel surfaces whereby a crease is formed in the strip along the scribed line, progressively at least partly flattening the crease along the scribed line whereby the strip separates into first and second strips on opposed sides of the scribed line and separating the first
• the present invention provides a method wherein a strip of amorphous metal is separated into first and second strips by scribing a line in a surface of the strip, folding and creasing the strip along the scribed line in the direction which encloses the scribed line and then at least partly flattening the strip.
• the strip separates into the first and second strips as the flattening operation proceeds along the strip.
• the facing cut edges of the first and second strips are moved apart once they are separated.
• the flattening operation may be continued until the crease is completely flattened or the crease may even be partly or completely reversed. Apparatus for executing this method is also provided.
• apparatus for slitting a strip of amorphous metal comprising means for transporting the strip in a direction, the means for transporting including means for producing a predetermined tension in the strip, a wheel-type scribing tool of the type including a wheel having a cutting edge thereon, the cutting edge including a cutting edge radius, means for contacting the cutting edge on a first surface of the strip of amorphous metal, a backup surface contacting a second surface of the strip opposing the wheel-type scribing tool, the means for contacting being effective for applying a predetermined scribing force to the cutting edge, the cutting edge radius and the predetermined force being jointly effective for scribing a scribe line in the surface as the strip is transported therepast, first and second mandrels having first and second facing surfaces spaced a first predetermined distance apart and disposed a second predetermined distance downstream of the wheel-type scribing tool, the second predetermined distance being effective to permit the
• a method for producing a magnetic core comprising scribing a line in a first surface of a strip of amorphous metal, folding opposed sides of the strip toward each other along the line to form a folded strip having the line within the fold, moving the opposed sides sufficiently close together adjacent the line to form a crease and least partly flattening the crease whereby the strip separates into first and second strips on opposed sides of the line and winding at least one of the first and second strips to form the magnetic core.
• the present invention provides a slitting apparatus for an amorphous metal strip which employs a scribing tool to form a scribed line in a surface of the strip as it is transported past the scribing tool.
• the scribed strip is folded toward the scribed line and creased between mandrels. Then the crease is flattened out against a flattening surface, whereupon the strip cleanly separates into first and second strips.
• a separating device downstream of the flattening surface moves the newly separated edges apart.
• Fig. 1 is a perspective view of a strip of amorphous metal to be separated into two strips along a substantially straignt line.
• Fig. 2 is a perspective view of the strip of amorphous alloy of Fig. 1 after receiving a scribed line in one surface thereof.
• Fig. 3 is a cross section taken along III-III of Fig. 2.
• Fig. 4 is a microscopic view of the amorphous alloy material.
• Fig. 5 is a cross section of an amorphous strip and a back-up surface showing one type of scribing tool which may be employed in the practice of the invention.
• Fig. 6 is a perspective view of a folded and creased strip of amorphous alloy.
• Fig. 7 is a cross section taken along VII-VII of Fig. 6 and showing a pair of opposed mandrels for creasing the strip.
• Fig. 8 is a perspective view showing the flattening and separating parts of the method in progress.
• Fig. 9 is a simplified schematic diagram of a slitting apparatus according to an embodiment of the invention.
• Fig. 10 is an enlarged top view of a strip of amorphous alloy passing between a pair of cylindrical mandrels.
• Fig. 11 is an enlarged top view of a strip of amorphous alloy passing between a pair of stationary semi-cylindrical mandrels.
• Fig. 12 is a close-up top view of a strip of amorphous alloy being flattened and separated.
• Fig. 13 is a cross section taken along XIII-XIII in Fig. 12.
• Fig. 14 is a cross section taken along
• Fig. 15 is a side view of a spindle-shaped crowned roller according to an embodiment of the invention.
• Fig. 16 is a side view of a turret-type wheel-type slitting tool suitable for use in one embodiment of the invention.
• Fig. 17A is a cross section of one shape of magnetic core which may be wound from a strip of amorphous metal alloy slit by the apparatus of the present invention.
• Fig. 17B is a foreshortened top view of a strip of amorphous metal alloy slit diagonally to form the magnetic core of Fig. 17A.
• Fig. 18A is a cruciform cross section of a magnetic core which may be wound using a strip of amorphous metal alloy slit by the apparatus of the present invention.
• Fig. 18B is a foreshortened top view of a strip of amorphous metal alloy slit in step-wise fashion to form the cruciform magnetic core of Fig. 18A.
• Fig. 19A is a round cross section of a magnetic core which may be wound using a strip of amorphous metal alloy slit by the apparatus of the present invention.
• Fig. 19B is a foreshortened top view of a strip of amorphous metal alloy sirt in sinusoidal fashion to form the round cross section magnetic core of Fig. 19A.
• Fig. 20 is an end view showing apparatus for controlling the transverse position of the scribing tool of Fig. 9 whereby the slit shapes of Figs. 17A-19B may be produced.
• Fig. 21 is a schematic diagram of a further apparatus for controlling the transverse position of the scribing tool.
• a strip of amorphous metal alloy 10 a strip of amorphous metal alloy 10.
• alloy 2605 S-2 manufactured by Allied Corp., and consisting of about 78 percent iron, 13 percent boron and 9 percent silicon.
• Strip of amorphous metal alloy 10 may be as long as convenient and may have a width as wide as can be cast using known or to-be-developed manufacturing techniques.
• a desired cutting line 12 is indicated in dashed line.
• cutting line 12 is shown to be straight and aligned with th-e length dimension of strip of amorphous metal alloy 10, a substantial curvature may be accommodated in cutting line 12 and the method of the present invention is successfully performed irrespective of the angle of cutting line 12 with respect to the length dimension of strip of amorphous metal alloy 10. That is, cutting line 12 may be oriented parallel to the length dimension as shown, normal to the length dimension, or at any angle in between.
• a scribe line 14 is formed along the line previously defined by cutting line 12. Scribe line 14 divides strip of amorphous metal alloy 10 into first and second parts 16 and 18 which typically fold slightly toward each other about scribe line 14. Referring now also to the cross section in Fig. 3, scribe line 14 forms a depression in strip of amorphous metal alloy 10. If strip of amorphous metal alloy 10 were of normal crystalline material, the formation of scribe line 14 would deform the material of the strip by pressing it to the sides and upward along scribe line 14 to form parallel linear mounds or berms. Such mounds or berms, if they existed, would degrade space factor. As shown in Fig. 3, however, the edges of scribe line 14 do not exhibit more than insignificant mounds, but instead, are substantially flat and parallel to the surfaces of part 16 and part 18.
• voids 22 may be displaced laterally away from scribe line 14. This displacement may nucleate cracks on the side of strip of amorphous metal alloy 10 opposite to the side being contacted by the tool forming scribe line 14 in the regions alongside scribe line 14 to which voids 22 are displaced. This permits the formation of scribe line 14 without displacing material to the sides and upward.
• Scribe line 14 may be formed by any convenient tool such as an awl, a knife edge and the like. Even though the material of strip of amorphous metal alloy 10 is hard and abrasive, the fact that scribe line 14 does not have to penetrate strip of amorphous metal alloy 10, but only contact and press against its surface, substantially reduces tool wear as compared to a cutting method where penetration of the strip exposes the cutting tool to cut edges of the strip.
• a wheel-type cutter of a type similar to a glass cutter, such as shown at 24 in Fig. 5, is particularly effective for forming scribe line 14.
• a wheel 26 is rotatably supported on an axle 28 between legs of a yoke 30.
• a back-up surface 32 supports strip of amorphous metal alloy 10 which is contacted by a cutting edge 34 of wheel 26 to produce scribe line 14.
• back-up surface 32 is preferably hard, unyielding and flat.
• back-up surface 32 is hard steel.
• a downward force, indicated by an arrow 36 urges yoke 30 into contact with strip of amorphous metal alloy 10 to form scribe line 14.
• the value of downward force 36 required increases with increasing cutting edge radius 38 to a value of downward force 36 of about 110 Newtons, at which time cutting edge radius 38 has degraded to slightly less than about 0.038 mm.
• a satisfactory range of values for downward force 36 may be from about 50 to about 100 Newtons to provide satisfactory scribing in a production environment.
• cutting edge radius 38 further degrades beyond a value of about 0.038 mm, a satisfactory scribe line 14 cannot be made regardless of the value of downward force 36 applied.
• cutting edge radius 38 wears beyond this value sharpening or replacement is required.
• the limiting value of cutting edge radius 38 beyond which a satisfactory scribe line 14 cannot be produced is approximately equal to about 1.5 times the thickness of strip of amorphous metal alloy 10. This may be a satisfactory approximation for a relationship between a limiting value for cutting edge radius 38 and a thickness of strip of amorphous metal alloy 10 over a reasonable range of thicknesses of strip of amorphous metal alloy 10.
• Scribe line 14 defines the fold so that strip of amorphous metal alloy 10 tends to fold accurately along it.
• Strip of amorphous metal alloy 10 is then creased along the fold by moving parts.16 and 18 toward each other to an effective degree of closeness at least in the vicinity of scribe line 14.
• the folding and creasing may be performed by a conventional bending brake which folds one side against the other in a single motion or a pair of spaced-apart stationary or rotating mandrels used between which strip of amorphous metal alloy 10 is drawn.
• folding is performed as strip of amorphous metal alloy 10 passes from wheel-type scribing tool 24 to the mandrels and the creasing occurs at a single point on strip of amorphous metal alloy 10 as that point passes the mandrels.
• mandrels 40 and 42 are shown spaced apart and moving parts 16 and 18 of strip of amorphous metal alloy 10 toward each other along scribe line 14 as strip of amorphous, metal alloy 10 is drawn between them.
• mandrels 40 and 42 are a pair of opposed rotatable rollers. It is also possible to satisfactorily perform the folding operation, manually using only the fingers.
• part 16 and part 18 need not be moved together into face-to-face contact with each other for successful performance of the method.
• permitting face-to-face contact between part 16 and part 18 as strip of amorphous metal alloy 10 passes between mandrels 40 and 42 causes binding which prevents part 16 and part 18 from adjusting themselves in the direction of motion. This can tend to force the crease off the cutting line defined by scribe line 14.
• a spacing is preferably established between mandrels 40 and 42 which permits a space 44 to exist between facing surfaces of part 16 and part 18.
• space 44 may vary for different alloys and thicknesses of strip of amorphous metal alloy 10, for a thickness of about 0.038 mm with the alloy previously defined, we have discovered that a spacing between mandrels 40 and 42 of about three times the thickness of strip of amorphous metal alloy 10, or about 0.075 mm, is satisfactory. This allows space 44 to assume a value about equal to the thickness of strip of amorphous metal alloy 10.
• crease is at least partly flattened out.
• strip of amorphous metal alloy 10 separates cleanly along scribe line 14 to provide two separate strips.
• Flattening can be performed in any convenient manner, but in the preferred embodiment, strip of amorphous metal alloy 10 is flattened at one end and then progressively flattened toward the other end as shown. The amount of flattening required varies with the sharpness of cutting edge radius 38. With a freshly sharpened cutting edge 34, parts 16 and 18 separate well before the crease is fully flattened out.
• Such reversal may include, for example, moving parts 16 and 18 together with scribe line 14 on the outside defining the apex of a reverse fold.
• parts 16 and 18 may be passed between a further pair of mandrels (not shown) which would complete the reversal by bringing the former outside surfaces of parts 16 and 18 close together at least in the vicinity of scribe line 14. It should be noted that the progressive flattening illustrated in Fig.
• edges 46 and 48 are preferably moved away from each other so that mechanical interlocking of edges 46 and 48 is avoided.
• edges 46 and 48 are clean without burrs, bumps or other artifacts of the slitting operation which would be detrimental to the space factor of a core wound from the separated strips.
• parts 16 and 18 are pulled laterally away from each other substantially as shown in Fig. 8 starting at one end and moving progressively to the other.
• the length to be cut is relatively short such as, for example, when cutting across strip of amorphous metal alloy 10
• an amount of pulling force is reached which is enough to sufficiently flatten the fold, the parts separate all along their lengths at substantially the same time in an almost explosive separation. An examination of the newly separated edges produced by this method shows that the same excellent edge cleanness is achieved as with the other flattening techniques.
• FIG. 9 One suitable apparatus for performing the scribing, folding, creasing, flattening and separating is shown in Fig. 9.
• a spool 50 holds a roll 52 of amorphous metal alloy 54 which is paid out under control of conventional feeding apparatus which may include, for example, first and second idler rolls 56 and 58 for forming a feed loop 60.
• Conventional sensing and control devices may be employed to control the length of feed loop 60 in order to ensure a reliable supply of amorphous metal alloy 54 for subsequent operations.
• a braking device which may be, for example, a pair of braking rollers 62 and 64, apply a predetermined braking force to amorphous metal alloy 54 passing between them.
• Braking rollers 62 and 64 may be of any conventional type such as, for example, a magnetic particle brake.
• Wheel-type scribing tool 24 is disposed on a first side of amorphous metal alloy 54.
• a back-up roll 66 is disposed on the opposite side of amorphous metal alloy 54.
• Wheel-type scribing tool 24 produces scribe line 14 on the upper surface of amorphous metal alloy 54 in Fig. 9.
• one embodiment illustrated in Fig. 9 includes a replaceable weight 68 which may be placed on, for example, a platform 70.
• a replaceable weight 68 may be increased as previously described until, when the radius of the cutting edge increases to the point where a satisfactory scribe line 14 can no longer be performed, a freshly sharpened wheel-type scribing tool 24 must be substituted for the wheel-type scribing tool 24 in use and the mass of replaceable weight 68 reduced appropriately to begin a further sequence of use.
• Resilient means such as, for example, a spring (not shown) may be substituted for replaceable weight 68 to produce downward force 36.
• the width of scribe line 14 may be employed as an indicator of the required value of downward force 36. More precise and responsive control of downward force 36 may be obtained using a feedback control system (not shown) which dynamically adjusts the value of downward force 36 according to the width of scribe line 14.
• a feedback control system (not shown) which dynamically adjusts the value of downward force 36 according to the width of scribe line 14.
• the width of scribe line 14 is measured using conventional apparatus such as, for example, a photo-optical sensor.
• the width is then employed to derive, or look up, a required value of downward force 36 using, for example, a lookup table, and this value of downward force 36 is applied to wheel-type scribing tool 24 using, for example, a conventional mechanical or hydraulic force actuator.
• amorphous metal alloy 54 After passing wheel-type scribing tool 24, amorphous metal alloy 54 is folded as it moves toward mandrels 40 and 42 where a crease is formed along the line defined by scribe line 14.
• An along-stream spacing 72 bet ⁇ veen wheel-type scribing tool 24 and mandrels 40 and 42 is sufficient to permit the edges of amorphous metal alloy 54 to curve upward without excessively lifting the edges alongside wheel 26 of wheel-type scribing tool 24.
• the required value of spacing 72 varies with the width of amorphous metal alloy 54.
• a minimum value of spacing 72 is about two or three times a width of amorphous metal alloy 54.
• a maximum value is established by the dimensions of the facility in which the slitting operation is being performed. For practical purposes, a value of spacing 72 of about ten times a width of amorphous metal alloy 54 is more than adequate.
• Mandrels 40 and 42 are illustrated as a pair of spaced-apart rollers.
• a stationary, non-rotating embodiment of mandrels 40' and 42' is shown which is effective for producing the crease along scribe line 14 in amorphous metal alloy 54.
• amorphous metal alloy 54 passes along a downstream spacing 74 and then over a flattening roller 76.
• a suitable combination of contact angle of amorphous metal alloy 54 with flattening roller 76 and a tension in amorphous metal alloy 54 causes amorphous metal alloy 54 to flatten in the transverse direction just as it makes contact with flattening roller 76.
• amorphous metal alloy 54 splits to form first and second part strips 78 and 80.
• Part strips 78 and 80 pass on opposite sides of a vertex 81 of a pyramidal prism 82 which tends to move the newly separated edges of part strips 78 and 80 apart and to thereby avoid mechanical keying together of the newly separated edges.
• pyramidal prism 82 at least partly reverses the fold after strip of amorphous alloy 54 loses contact with flattening roller 76.
• the partial reversal of the crease may be useful in achieving separation under certain conditions, particularly of the combination of the sharpness of cutting wheel 26 and the value of downward force 36.
• a tension drive motor 88 applies a torque to drive roller 84 which is effective to apply a predetermined tension to amorphous metal alloy 54. After being tensioned and pulled through the slitting apparatus by drive roller 84 and pinch roller 86, part strips 78 and 80 pass on to conventional take-up reels (not shown).
• Fig. 9 is highly schematic and simplified in order to support a clear and complete disclosure of the elements which we consider to comprise our Invention.
• a conventional device (not shown) for measuring tension in amorphous metal alloy 54 is preforrably included to permit dynamic control of tension drive motor 88 in order to maintain the tension in amorphous metal alloy 54 at the predetermined value.
• tension drive motor 88 may be manually controlled to produce a tension in amorphous metal alloy 54 which satisfies empirical parameters to be explained hereinafter.
• pyramidal prism 82 The positioning and shape of pyramidal prism 82 is established to produce an amount of separating force on amorphous metal alloy 54 and a partial reversal of the fold acting at about the location where amorphous metal alloy 54 moves out of contact with flattening roller 76 effective to move part strips 78 and 80 apart without applying so little separating force that poor edge quality is produced or so much that the edges of part strips 78 and 80 become distorted.
• the use of pyramidal prism 82 has the advantage of simplicity since pyramidal prism 82 is a purely passive component interposed in the path of part strips 78 and 80.
• first and second angled separation rollers 90 and 92 are replaced with first and second angled separation rollers 90 and 92.
• Angled separation rollers 90 and 92 may be stationary or rotatable and, if rotatable, may be passive or driven.
• the separating force and partial fold reversal produced by angled separation rollers 90 and 92 (or pyramidal prism 82) is combined with the tension in amorphous metal alloy 54 and the sharpness and downward force on wheel 26 to produce clean slit edges.
• the point at which separation occurs can vary from upstream of flattening roller 76, particularly when wheel 26 is freshly sharpened, a point in contact with flattening roller 76 or a point downstream of flattening roller 76. It is even possible that separation may eves take place downstream of angled separation rollers 90 and 92.
• the most stable operation of the apparatus is achieved when the parameters are adjusted so that separation takes place just before, during or after amorphous metal alloy 54 first contacts flattening roller 76.
• FIG. 13 The sequence of cross sections in Figs. 13 and 14 show the empirical result of the correct combination of the tension and separating-force parameters.
• Amorphous metal alloy 54 first contacts flattening roller 76 along a line indicated by a dashed line 94 in Fig. 12, remains in contact with flattening roller 76 over a portion of the rotational angle of flattening roller 76 and then moves out of contact with flattening roller 76 at a second dashed line 96.
• dashed line 94 Just before reaching dashed line 94, amorphous metal alloy 54 is only partially flattened as shown in Fig. 13. Referring now to Fig.
• flattening roller 76 may be replaced with a suitably shaped stationary surface (not show) against which amorphous metal alloy may be flattened in a manner completely analogous to the above detailed description.
• functions of flattening roller 76 and angled separation rollers 90 and 92 may both be performed by a spindleshaped crowned roller 98 such as shown in Fig. 15.
• Fig. 16 there is shown an improved wheel-type scribing tool 24' which may be employed in the present invention.
• FIG. 9 is replaced by multiple wheel-type scribing tools 24' in a turret arrangement so that, upon one cutting edge 34 becoming dull or damaged, a new cutting edge 34 can be swivelled into place without loss of running time of the apparatus.
• Another possibility for extending the run time for a cutting edge 34 includes continuous sharpening of cutting edge 34 while it is in use.
• a diamond-impregnated sharpening wheel (not shown) may be urged against wheel 26 and optionally rotated to maintain cutting edge 34 in satisfactorily sharp condition for an extended cutting run.
• amorphous metal alloy 54 is to obtain a separated shape which, when wound on a mandrel provides a cross section which conforms more closely to the shape of a wire coil wound around it than is possible if only square or rectangular cross sections were available.
• Amorphous metal alloy 54 Is separated by a single diagonal slit 102 into two triangular part strips 78 and 80. Each of part strips 78 and 80 may be wound on a mandrel (not shown) to produce a core with a triangular cross section or they may be wound end-to-end as shown in Fig.
• Fig. 17A to produce a core 104 with a square cross section and with the laminations of the core running in the direction of the cross hatching.
• the single diagonal slit 102 of Fig. 17B has the advantage that all of the slit material is usable. Since the cost of amorphous metal alloy 54 is currently quite high, normal applications may not support the cost of a core whose production requires a substantial scrap rate of the material. Certain applications which are cost inelastic may warrant the improved cross-sectional shape afforded by the slitting patterns of Figs. 18A, 18B, 19a and 19B at the expense of a substantial scrap rate. In the embodiment shown in Figs.
• a stepped slit 102 along one edge of amorphous metal alloy 54 and a corresponding stepped slit 102' along an opposite edge of a second amorphous metal alloy 54' produce two strips which, when wound on a mandrel with their uncut edges 103 in abutment, produce a core 106 having a cruciform or any other suitable stepped cross section.
• the slitting technique of Figs. 18A and 18B can reproduce substantially any desired polygonal cross section.
• a slitting pattern is shown which can produce a substantially round core 108.
• Slits 102 and 102' on opposed sides of amorphous metal alloys 54 and 54' follow a long sinusoidal path which, when amorphous metal alloys 54 and 54' are wound on a mandrel with their uncut edges 103 in abutment, produce a round or ovate core 108.
• the slitting patterns and resulting core shapes described in the preceding should be taken as exemplary only and not as an exhaustive set of the possibilities.
• the present invention provides sufficient flexibility to create a finished strip from which virtually any desired core cross-sectional shape can be wound.
• amorphous metal alloy 54 may be measured inkilometers and the width in, at most a few cm, controlling the transverse position of slit 102 to produce the desired core cross section is not a trivial task.
• Fig. 20 there is shown one embodiment of an apparatus which may be used to control the side-to-side movement of a wheel-type scribing tool 24".
• a lead screw 110 is threaded into a body 112 of wheel-type scribing tool 24".
• Lead screw 110 is rotated by a scriber drive motor 114 which is responsive to control signals from a control system 116 to thereby drive wheel 26 transversely across amorphous metal alloy 54 and to thereby produce the desired shape of scribe line 14 which results in a corresponding shape of slit 102.
• a sensing wheel 118 contacts a peripheral surface of back-up roll 66 as shown, or alternately, contacts a surface of amorphous metal alloy 54 to produce a length signal responsive to the passage of amorphous metal alloy 54 through the apparatus. The length signal is applied to control system 116 wherein it is translated into a command for application to scriber drive motor 114.
• control system 116 may be a conventional pulse generator which produces a single pulse each time sensing wheel 118 senses the passage of a predetermined length of amorphous metal alloy 54.
• Scriber drive motor 114 may be a stepping motor which responds to each pulse from control system 116 with a small unidirectional rotational step which, in turn, produces a small unidirectional translational step of wheel-type scribing tool 24".
• control system 116 may contain a length-to-width lookup table using, for example, a microprocessor, for providing bi-directional drive signals to scriber drive motor 114. Since the hardware for implementing a lookup table and for producing a bi-directional drive signal in response thereto is well known in the art, further description thereof is omitted.
• an equivalent apparatus to that described in the preceding includes one in which wheel-type scribing tool 24" remains stationary while amorphous metal alloy 54 is moved transversely by the equivalent of control system 116.
• wheel-type scribing tool 24" Due to the gradualness with which wheel-type scribing tool 24" is translated across the width of amorphous metal alloy 54 compared to the relatively great length of amorphous metal alloy 54 passing between steps, no difficulty may be encountered in maintaining desired tracking of cutting edge 34 along the desired cutting line 12. If a tendency develops for the lateral translation of wheel-type scribing tool 24" to physically shift amorphous metal alloy 54 sideways rather than to move scribe line 14 with respect to the edges of amorphous metal alloy 54, a slight trailing-arm caster (not shown) may be added to wheel-type scribing tool 24" to aid in permitting scribe line 14 to track the desired cutting line 12.
• the thickness of amorphous metal strips made by current processes is variable.
• Fig. 21 A preferred technique is illustrated in Fig. 21 wherein half strip 78, instead of being wound on a take-up reel, instead is wound directly on a mandrel 122 for forming a core 122 as the slitting operation is being performed.
• a sensing device 124 senses the thickness or build of core 122 as it is being wound and transmits a signal representing this value to control system 116.
• Control system 116 employs the existing build of core 122 in setting a transverse position of wheel-type scribing tool 24" in the manner previously explained.
• Sensing device 124 may be of any convenient type such as, for example, electromechanical, electromagnetic or electrooptical. For purposes of concreteness, sensing device 124 is shown to include a variable resistor 126 whose resistance is varied by an actuating arm 128 connected to an idler roller 130 which is resiliently urged to contact a surface of core 122.

Landscapes

• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Life Sciences & Earth Sciences (AREA)
• Forests & Forestry (AREA)
• Mechanical Engineering (AREA)
• Re-Forming, After-Treatment, Cutting And Transporting Of Glass Products (AREA)
• Manufacturing Cores, Coils, And Magnets (AREA)
• Shearing Machines (AREA)

Applications Claiming Priority (4)

Publications (2)

Family

ID=27076335

Family Applications (1)

Country Status (6)

Families Citing this family (2)

Citations (3)

Family Cites Families (5)

• 1985
  • 1985-01-18 IT IT19143/85A patent/IT1184115B/it active
  • 1985-01-25 JP JP85500788A patent/JPS61501380A/ja active Pending
  • 1985-01-25 EP EP19850901150 patent/EP0171425A4/fr not_active Withdrawn
  • 1985-01-25 KR KR1019850700233A patent/KR850700285A/ko not_active Application Discontinuation
  • 1985-01-25 BR BR8504921A patent/BR8504921A/pt unknown
  • 1985-01-25 WO PCT/US1985/000117 patent/WO1985003379A1/fr not_active Application Discontinuation

Patent Citations (3)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events