Title of Invention

A METHOD OF AND AN APPARATUS FOR MAKING A STACKED STRIP BLOCK OF AMORPHOUS MAGNETIC METAL

Abstract

A method of and an apparatus for making a stacked strip block of amorphous magnetic metal by feeding a continuous composite strip of amorphous magnetic metal until a leading end of the continuous composite strip is clamped by at least one strip feed clamp, pulling the continuous composite strip a pre-determined feed distance along a stationary table while the leading end is clamped by the strip feed clamp, and cutting the continuous composite strip to provide a generally rectangular composite cut strip. The pulling and cutting are alternately repeated a number of cycles until a desired number of the composite cut strips corresponding are stacked one above the other on the stationary table to thereby provide a multilayered strip and, also, are repeated sequentially a number of times until a corresponding number of the multilayered strips are stacked one above the other on the stationary table to thereby provide the stacked strip block. A multilayered strip forming process of forming a plurality of the multilayered strips, and a stepwise shift process of clamping a portion of the multilayered strips by means of at least one stepwise shift clamp and driving the stepwise shift clamp to displace the multilayered strips a predetermined shift distance relative to each other each time the multilayered strip is formed are alternately carried out a pre-determined number of cycles until the stacked strip block composed of the plural multilayered strips is formed. PRICE: THIRTY RUPEES

Full Text

The present invention relates to a method of and an apparatus for making a stacked strip block of amorphous magnetic metal that is used to form the core by winding the stacked strip block around a former such as a mandrel complemental in shape to the core configuration. As a magnetic core for an electrical stationary inductive apparatus such as a transformer, one-turn cut type wound core has been used. The one-turn cut type transformer core made by the use of lengths of amorphous magnetic alloy is generally assembled by laminating a plurality of multilayered strips, each formed by cutting a continuous composite strip of amorphous magnetic alloy into a plurality of composite cut strips which are then laminated, one above the other to provide a stacked strip block and then by stacking a plurality of stacked strip blocks one above the other with their opposite ends either stepped or staggered repeating in stairstep fashion to eventually provide a step-lap joint or aligned with each other to eventually provide a butt joint. Fig. 13 of the accompanying drawing illustrate an example of the one-turn cut type wound core of a cylindrical configuration, in which three stacked strip blocks B1 to B3 are employed, having their respective stepped ends connected together in a step-lap joint J which lies intermediate the region in which the ends are progressively stepped as indicated between the imaginary lines 01-01 and 02-02. Where the transformer core is desired to ba assembled so as to have a generally rectangular configuration, the cylindrical core shown in Fig. 13 is subsequently shaped into a generally rectangular configuration, followed by annealing the shaped core including opposite leg portions C1 and 02 and opposite bridge portions Y1 and Y2 substantially perpendicular to the leg portions C1 and C2 as shown in Fig. 14. Various joint designs for the wound cores have hitherto been suggest¬ed, the details of joints of the stacked strip blocks of one of which are shown in Fig. 15 in which joints are exaggerated for illustration as if each joint were to have a gap. Referring to Fig. 1 5, the joint design known as a lap joint is shown in which the stacked strip blocks are assumed to have been wound around a mandrel in a clockwise direction with respect to the axis of rotation of the mandrel. In the illustrated joint design, the innermost one U^ of the multilayered strips of the innermost stacked strip block B-| has a length L-j equal to the circumference R-i of the outer peripheral surface of the mandrel and is turned around the mandrel with its opposite ends butted together. The multilayered strip U2 of the innermost stacked strip block B-j subsequently turned over the innermost multilayered strip U-j around the mandrel has a length l_2 which is equal to [R-j + La + 2/rt] (wherein t represents the thick¬ness of the multilayered strip, La is equal to or greater than Lo and represents a lap margin at which the opposite ends overlap one above the other. Accordingly, when the second multilayered strip U2 is turned over the innermost multilayered strip U-| around the mandrel with its leading end displaced a distance Lo from the trailing end of the innermost multilayered strip U^, the trailing end of the second multi-layered strip Uo comes to a position above the leading end thereof so as to overlap the latter in a lap margin La. In this way, the subsequent multilayered strips Un that are successively turned around the mandrel so as to overlap one above the other are prepared to have progressively increasing lengths Ln which is equal to [R I + La + 2/7t] so that, when they are wound successively around the mandrel, the opposite ends of each multilayered strip can overlap with each other in the lam margin La. Rn_-j referred to above is equal to [R-| + (n - 2)-2m], provided that n is equal to or greater than 2. The multilayered strips of the subsequent stacked strip blocks have their lengths chosen in a manner similar to that described in connection with the multilayered strips of the innermost stacked strip block B-j and are successively wound over the innermost stacked strip block B^ in a manner similar to that described in connection with the innermost stacked strip block Bi. An apparatus for making a one-turn cut type core by the use of silicon-containing steel plates is known, which comprises a stacking unit shown in Fig. 16 and a winding unit shown in Fig. 17. Where the wound core having the joint design shown in Fig. 15 is to be assembled by the use of the silicon-containing steel plates, the multilayered strips Un discussed above are replaced with silicon-containing steel strips cut to a predetermined length. In the description which follows, the same reference characters U-|, l^, as used in connection with the multilayered strips are used to denote the silicon-containing steel strips for the purpose of clarity. The stacking apparatus shown in Fig. 16 is disclosed in the Japanese Patent Publication No. 5-67046, published in 1993, and comprises a feeder 1 including a motor-coupled feed roller 1A and a pinch roller 1B cooperable with the feed roller 1Ato sandwich and feed a continuous silicon-containing steel strip SS, a shearing unit 2 for cutting the continuous silicon-containing steep strips SS to provide the cut silicon-containing steel strips U-|, l^, , a stationary table 4 positioned on a downstream side of the shearing unit with respect to the direction of feed, a movable table 5 positioned between the stationary table 4 and the shear¬ing unit 2, a stepwise feed clamp 7 adapted to be driven by a cylinder 6 to cause the silicon-containing steep strip, cut by the shearing unit 2, to be clamped between it and the movable table 5, a stepwise transport unit 8 for driving the movable table 5 a predetermined distance stepwise together with the stepwise feed clamp 7, an end clamp 10 adapted to be driven by a cylinder 9 to clamp a leading end of a laminated strip block composed of a stack of the silicon-containing steel strips in cooperation with the stationary table, a screw rod 11b driven by an electric motor 11a, and an end clamp drive mechanism 11 including a nut thread- ' ingly mounted on the screw rod 11b for moving the end clamp 10 in a direction conforming to the direction of feed. The stepwise transport unit 8 includes a cam mechanism driven by a drive source, which may be an electric motor used to drive the shearing unit 2, for reciprocately driving the movable table 5 and is so designed and so configured that each time the continuous silicon-containing steel strip SS has been cut to provide the silicon-containing steel strip with a movable blade of the shearing unit having been retracted, the movable table 5 can be advanced towards the stationary table 4 a distance which corresponds to the sum of the length of such silicon-containing steel strip so cut plus the lap margin La determined in consideration of the thick¬ness of the silicon-containing steel strip and the circumference of the mandrel or the wound silicon-containing steel strip immediately radially inwardly of the silicon-containing steel strip to be wound, followed by return of the movable table 5 back to the initial position when the stepwise feed clamp 7 is released to unclamp the silicon-containing steel plate. The winding apparatus shown in Fig. 17 includes, in addition to the mandrel m, pulleys P, a generally endless winding belt V trained between the pulleys P with one of opposite runs thereof turned around the mandrel m for guiding the stacked strip block between the outer peripheral surface of the mandrel m and such one of the opposite runs of the endless belt V so as to be turned around the mandrel m, and a drive mechanism (not shown) for driving the endless belt V. In order for the transformer core of the type having the joint design shown in Fig. 13 to be assembled by the use of the stacking apparatus shown in Fig. 16, the continuous steel strip SS should first be supplied by the feeder 1 a distance L-i equal to the circumference R-1 of the mandrel m, followed by activation of the shearing unit 2 to cut the continuous steel strip SS to provide a cut stee strip U-j of the innermost stacked strip block B^. The cut steel strip U1 is sub sequently clamped against the movable table 5 by the stepwise feed clamp 7 and is then advanced leftwards, as viewed in Fig. 16, by the stepwise transport unit 8 together with the movable table 5 a distance equal to the lap margin La plus 2rrt, that is, [La + 2/rt]. After the stepwise feed clamp 7 has been undamped, that is, has released the cut steel strip U-|, the movable table 5 is returned to the initial position and, thereafter, the end clamp 10 is activated to clamp the leading end of the cut steel strip U^ against the stationary table 4. Thereafter, the feeder is activated again to supply the continuous steel strip SS so as to overlay the cut steel strip U-j. When it is detected that the continuous steel strip SS has been supplied a distance equal to the sum of the length of the cut steel strip U^ plus 2nt (wherein t represents the thickness of the steel strip), the shearing unit 2 is activated to cut the continuous steel strip SS to provide another cut steel strip U2 which is subsequently placed above the cut steel strip U-i. A lamination of the cut steel plates U-j and U2 is then clamped against the movable table 5 by means of the stepwise feed clamp 7 and, after the end clamp 10 has been undamped, the movable table 5 is advanced a shift distance of [La + 2/rt] by the stepwise transport unit 8 together with the cut steel strips U-| and LU and the stepwise feed clamp 7. After this advance, the stepwise feed clamp 7 is undamped to allow the movable table 5 to return to the initial position, followed by drive of the end clamp 10 to a position where it is brought into engagement with the leading end of the cut steel strip U2 to thereby allow the end clamp 10 to clamp the leading end of the lamination of the cut steel strips U-j and U2. In a manner similar to that described above, stepwise shift of the steel strip lamination over the distance of [La + 2rrt] and overlapping of a cut steel strip of a length increased by 2nt on the steel strip lamination are alternately repeated a desired number of cycles to provide the stacked steel block B-,,. It is to be noted that the increment, 2/rt, of the length of the cut steel strip is necessitated because as the number of the cut steel strips or stacked steel blocks turned around the mandrel m increases, the apparent circumference of the outermost cut steel strip or stacked steel block increases at the rate of 2/rt. The stacked steel block B^ referred to above corresponds to the stacked steel block B-| shown in Fig. 13 as developed in a plane and one of the opposite ends of such stacked steel block have steps progressively shifted a lap margin La whereas the other of the opposite ends of such stacked steel block have steps progressively shifted a lap margin La plus 2/7t. The stacked steel blocks B^ and Bg> to be subsequently stacked on the stacked steel block B-j/ are successively formed in a manner similar to that described in connection with the formation of the stacked steel block B-| > to provide the lamination of the stacked steel blocks B-| • to B3/ which is subsequently fed in between the endless bent V and the peripheral surface of the mandrel m of the winding unit shown in Fig. 17. to thereby complete the transformer core having the joint design shown in Fig. 13. With the prior art stacking apparatus shown in Fig. 16, when the (n + 1 )-th cut steel strip Un + -j of a length greater by 2/7t than that of the cut steel strip Un positioned immediately below the (n + 1}-th cut steel strip Un + 1 is to be overlapped on the (n + 1 )-th cut steel strip Un + ^, it is necessary that the cut steel strips Un, Un.-|, l).| which have already been stacked must be indexed or shifted stepwise a distance equal to the sum of the lap margin La plus 2/rt. In addition, the utmost care must be taken to avoid the possibility that, when the (n + 1 )-th cut steel strip Un + -j is to be overlapped on the n-th cut steel strip Un, the stacked cut steel strips following the n-th cut steel strip may be displaced in position by the effect of a frictional force induced between the cut steel plate Un and the cut steel plate Un+1. Once such a displacement occur, the resultant transformer will be deteriorated in quality, accompanied by reduction in character^ tic thereof. For this reason, the prior art stacking apparatus shown in Fig. 16 is provided with a combination of the movable table 5, the cylinder 6, the stepwise feed clamp 7 and the stepwise transport unit 8 for accomplishing indexing or stepwise shift of the cut steel strips to be stacked one above the other and also with a combination of the cylinder 9, the end clamp 10 and the end clamp drive mechanism 11 for avoiding the undesirable displacement among the stacked cut steel strips. Where the transformer core is desired to be assembled by the use of the silicon-containing steel plate such as discussed above, the prior art apparatus is satisfactory to accomplish an automated stacking of the steel plates. However, by the reason which will subsequently be described, such prior art stacking apparatus cannot be used where the transformer core is desired to be assembled by the use of the amorphous magnetic alloy strips. When the prior art stacking apparatus shown in Fig. 16 is used to assembly the transformer core by the use of the amorphous magnetic alloy strips, the continuous steel strip SS has to be replaced with a continuous composite strip of amorphous magnetic alloy and must be supplied by the feeder 1, followed by cutting by the shearing unit the continuous composite strip to eventually form the multilayered strips U-|, l^, successively. However, as is well known to those skilled in the art, the amorphous magnetic alloy strip is extremely thin and fragile and, therefore, when an attempt is made to feed the continuous composite strip by passing it through the feed roller 1A and the pinch roller 1B of the feeder 1 onto a predetermined position above the stationary table 4, the continuous composite strip being fed will undergo an undulating motion and/or a warping motion to such an extent that no multilayered strip will be properly formed. In addition, the amorphous magnetic alloy strip is also hard and, therefore, when the continuous composite strip to be used has a thickness corresponding to the thickness of the eventually formed multilayered strip, not only would cutting of the amorphous magnetic alloy strip be difficult to achieve, but the shearing unit will quickly be reduced in lifetime thereof. By the foregoing reason, the prior art stacking apparatus shown in Fig. 16 cannot be employed where the transformer core is desired to be assembled by the use of the amorphous magnetic alloy and a job of forming the multilayered strips U.|, l^, and a job of forming the stacked blocks B^, B2', each being a stack of the multilayered strips have been carried out manually, accom¬panied by a considerable reduction in workability. SUMMARY OF THE INVENTION Accordingly, the present invention is intended to provide an improved strip stacking method of and an improved strip stacking apparatus for making a stacked strip block of amorphous magnetic metal for a transformer core, wherein a process of forming the stacked strip blocks each comprised of a stack of the multilayered strip of amorphous magnetic alloy one above the other is automated without substantially requiring manual intervention. To this end, the strip stacking method of the present invention comprise the steps of feeding a continuous composite strip of amorphous magnetic metal by means of a feeder in one transport direction towards a clamp station past a cutting station where a shearing unit is disposed, until a leading end of the continuous composite strip with respect to the transport direction is clamped by at least one strip feed clamp; while the leading end of the continuous composite strip is clamped by the strip feed clamp, pulling the continuous composite strip a pre¬determined feed distance along a stationary table positioned on one side of the cutting station downstream with respect to the transport direction; cutting the con¬tinuous composite strip by means of the shearing unit to provide a generally rectangular composite cut strip of a length corresponding to said predetermined feed distance; said pulling and cutting steps being alternately repeated a number of cycles until the composite cut strips corresponding in number to the number of cycles are stacked one above the other on the stationary table to thereby provide a multilayered strip; cyclically repeating the pulling and cutting steps sequentially a number of times until a corresponding number of the multilayered strips are stacked one above the other on the stationary table to thereby provide the stacked strip block, wherein a multilayered strip forming process of forming a plurality of the multilayered strips on the stationary table by cyclically repeating said cyclically repeating step, and a stepwise shift process of clamping a portion of the multi-layered strips by means of at least one stepwise shift clamp in cooperation with a corresponding movable plate means movable along the stationary table and driving the stepwise shift clamp to displace the multilayered strips a predetermined shift distance along the stationary table relative to each other in a direction downstream of the transport direction each time the multilayered strip is formed, to thereby cause the respective leading ends of the multilayered strips to be progressively stepped, are alternately carried out a predetermined number of cycles until the stacked strip block composed of the plural multilayered strips is formed. Preferably, the predetermined feed distance the continuous composite strip is pulled is increased stepwise for each cycle of the pulling and cutting steps such that the resultant plural multilayered strips have different lengths. The present invention also provides a strip stacking apparatus which performs the above described method of the present invention for making a stacked strip block of amorphous magnetic metal. This strip stacking apparatus comprises at least one feeder for feeding a continuous composite strip of amorphous magnetic metal in one transport direction towards a clamp station past a cutting station where a shearing unit is disposed, until a leading end of the continuous composite strip with respect to the transport direction is clamped by a strip feed clamp means; said strip feed clamp means being, while the leading end of the continuous composite strip is clamped by the strip feed clamp means, operable to pull the continuous composite strip a predetermined feed distance along a stationary table positioned on one side of the cutting station downstream with respect to the transport direction; a shearing unit disposed at the cutting station for cutting the continuous composite strip to provide a generally rectangular composite cut strip of a length corresponding to said predetermined feed distance; a stepwise shift clamp means cooperable with a corresponding movable plate to clamp a portion of the multilayered strips, said stepwise shift clamp means being movable together with the movable plate in a direction downstream of the transport direction to displace the multilayered strips a predetermined shift distance along the stationary table relative to each other in a direction downstream of the transport direction each time the multilayered strip is formed, to thereby cause the respective leading ends of the multilayered strips to be progressively stepped, and a control means for executing the strip stacking method as defined in any one of Claims 1 to 3 to thereby complete the stacked strip block. Preferably, the strip feed clamp means comprises first and second strip feed clamps and said stepwise shift clamp means comprises first and second stepwise shift clamps and in that said first and second strip feed clamps are operated alternately the continuous composite strip each time the composite cut strip is formed and said first and second stepwise shift clamps are operated in response to alternate operation of the first and second strip feed clamps. In any event, according to a broad aspect of the present invention, the use of a single strip feed clamp in combination with a corresponding single stepwise shift clamp, instead of the use of the two strip feed clamps in com-oination with the corresponding stepwise shift clamps as discussed above in connection with the illustrated embodiment, is sufficient to accomplish the abjective of the present invention. Accordingly the present invention provides a method of making a stacked strip block of amorphous magnetic metal, which method comprises the steps of: feeding a continuous composite strip of amorphous magnetic metal by means of a feeder in one transport direction towards a clamp station past a cutting station l where a shearing unit.is disposed, until a leading end of the continuous composite strip with respect to the transport direction is clamped by at least one strip feed clamp; while the leading end of the continuous composite strip is clamped by the strip feed clamp, pulling the continuous composite strip a predetermined feed distance along a stationary table positioned on one side of the cutting station downstream with respect to the transport direction; cutting the continuous composite strip by means of the shearing unit to provide a generally rectangular composite cut strip of a length corresponding to said predetermined feed distance; said pulling and cutting steps being alternately repeated a number of cycles until the composite cut strips corresponding in number to the number of cycles are stacked one above the other on the stationary table to thereby provide a multilay-ered strip; cyclically repeating the pulling and cutting steps sequentially a number of times until a corresponding number of the muitilayered strips are stacked one above the other on the stationary table to thereby provide the stacked strip block; wherein a muitilayered strip forming process of forming a plurality of the multiiayered strips on the stationary table by cyclically repeating said cyclically repeating step, and a stepwise shift process of clamping a portion of the multi-layered strips by means of at least one stepwise shift clamp in cooperation with a corresponding movable plate means movable along the stationary table and driving the stepwise shift clamp to displace the muitilayered strips a predetermined shift distance along the stationary table relative to each other in a direction downstream of the transport direction each time the multilayered strip is formed, to thereby cause the respective leading ends of the multilayered strips to be progressively stepped, are alternately carried out a predetermined number of cycles until the stacked strip block composed of the plural multilayered strips is formed. Accordingly the present invention also provides a strip stacking apparatus for making a stacked strip block of amorphous magnetic metal, which comprises: at least one feeder for feeding a continuous composite strip of amorphous magnetic metal in one transport direction towards a clamp station past a cutting station where a shearing unit is disposed, until a leading end of the continuous composite strip with respect to the transport direction is clamped by a strip feed clamp means, said strip feed clamp means being, while the leading end of the continuous composite strip is clamped by the strip feed clamp means, operable to pull the continuous composite strip a predetermined feed distance along a stationary table positioned on one side of the cutting station downstream with respect to the transport direction; a shearing unit disposed at the cutting station for cutting the continuous composite strip to provide a generally rectangular composite cut strip of a length corresponding to said predetermined feed distance said apparatus comprises a stepwise shift clamp means cooperable with a corresponding movable plate to clamp a portion of the multilayered strips, said stepwise shift clamp means being movable together with the movable plate in a direction downstream of the transport direction to displace the multilayered strips a predetermined shift distance along the stationary table relative to each other in a direction downstream of the transport direction each time the multilayered strip is formed, to thereby cause the respective leading ends of the multilayered strips to be progressively stepped; and a control means for executing the strip stacking method as defined above to thereby complete the stacked strip block. BRIEF DESCRIPTION OF THE DRAWINGS This and other objects and features of the present invention will become clear from the following description taken in conjunction with a preferred embodiment thereof with reference to the accompanying drawings, in which like parts are designated by like reference numerals and in which: Fig. 1 illustrates in a schematic side view an in-line production machine for manufacturing a cylindrical amorphous magnetic core from a supply of the strip of amorphous magnetic metal alloy; Fig. 2 is a fragmentary side view, on an enlarged scale, showing a strip stacking apparatus according to the present invention; Fig. 3 is an end view of the strip stacking apparatus shown in Fig. 2, as viewed along the direction shown by the arrow A in Fig. 2; Fig. 4 is a schematic perspective view, on a further enlarged scale, showing a first strip feed clamp in combination with a first stepwise feed clamp; Fig. 5 is a schematic perspective view, on a further enlarged scale, showing tail clamps held in an unclamp position; Fig. 6 is a view similar to Fig. 5, showing the tail clamps held in a clamp position; Fig. 7 is a view similar to Fig. 5, showing a continuous composite strip of amorphous magnetic allow being pull-fed; Figs. 8(A) to 8(H) are schematic diagrams showing the sequence of operation of the strip stacking apparatus according to the present invention; Figs. 10 to 12 are flowcharts showing the sequence of operation of the in-line production machine shown in Fig. 1, including the sequence of operation of the strip stacking apparatus; Fig. 13 is a schematic plan view of the round transformer core; Fig. 14 is a schematic plan view of the rectangular transformer core; Fig. 15 is a schematic diagram showing joints employed in the transformer core; Fig. 16 is a schematic diagram showing the prior art stacking apparatus, including a strip supply and a shearing unit; and Fig. 17 is a schematic diagram showing the prior art winding apparatus. DETAILED DESCRIPTION OF THE EMBODIMENTS In describing some preferred embodiments of the present invention, reference is made to the manufacture of a cylindrical transformer core of the structure shown in Fig. 15 from a continuous composite strip of amorphous magne¬tic metal alloy by successively forming a plurality of multilayered strips Up (n = 1, 2, 3, ) and then stacking the multilayered strips Un (n = 1,2, 3, ) one above the other in a fashion with one multilayered strip progressively displaced a predetermined shift distance La from the next adjacent multilayered strip in a lengthwise direction thereof to form respective stacked strip blocks Bn (n = 1,2, 3, ). The multilayered strips Un have a different length which is incremented by a quantity equal to the circumference of the respective multilayered strip when the latter is turned round to assume a shape similar to the shape of the transformer core, that is, by 2nt wherein t represents the thickness of the multilayered strip. In the practice of a strip stacking method of stacking the multilayered strips of amorphous magnetic metal alloy one above the other to provide a stacked strip block in accordance with the present invention, a continuous composite strip of amorphous magnetic metal alloy, which is prepared from a plurality of elongated plies of amorphous magnetic metal alloy, is supplied in a direction lengthwise thereof through a shearing unit to provide a plurality of composite cut strips, Those composite cut strips or a plurality of laminations each including a plurality of the composite cut strips are then stacked one above the other to provide a multilayered strip. A plurality of the multilayered strips having a different length which is incre- mented by a quantity equal to the circumference of the respective multilayered strip when the latter is turned round, that is, by 2rrt wherein t represents the thickness of the multilayered strip are stacked one above the other on a stationary table in Oy a fashion with one multilayered strip progressively displaced the predetermined shift distance La from the next adjacent multilayered strip in a lengthwise direction thereof to form a stacked strip block having its opposite ends that are stepped. In the practice of the present invention, two process steps are repe¬ated alternately until the stacked strip block is formed. Those two process steps are (1) a multilayered strip forming process of forming the multilayered strip on the stationary table by repeating a predetermined number of cycles a process of clamp¬ing a leading end of the composite strip which has been fed by a feeder along the stationary table through a cutting gap, defined between shearing blades of the shearing unit, to a clamp position where the leading end of such composite strip is held in the vicinity of the cutting gap and then cutting the composite strip by the shearing unit into a plurality of the composite cut strips after the composite strip which had been restrained by the feeder has been released is moved a predeter¬mined distance in a direction conforming to the direction of feed thereof, and (2) a stepwise shift process of feeding the multilayered strips, which have been stacked one above the other on the stationary table, in a direction conforming to the direction of feed thereof so as to move them relative to each other in a lengthwise direction a distance corresponding to the shift distance La. Referring now to Figs. 1 to 8, Fig. 1 illustrates in a schematic side view an in-line production machine for manufacturing a cylindrical amorphous magnetic core from a supply of the strip of amorphous magnetic metal alloy, includ¬ing a strip stacking apparatus, whereas Figs. 2 to 7 illustrate the details of the strip stacking apparatus and Fig. 8 illustrates the sequence of operation of the strip stacking apparatus. It is to be noted that in the illustrated embodiment the strip stacking apparatus employed therein is shown to comprise first and second strip feed clamps SF1 and SF2 and first and second stepwise shift clamps SC1 and SC2 as will become clear from the subsequent description. A generally elongated stationary table T is supported by a machine framework (not shown) with at least an upper surface thereof oriented horizontally. A feeder 21 is positioned upstream of a trailing end 20a of the stationary table T with respect to the direction of feed of a continuous composite strip AS of amor¬phous magnetic metal alloy shown by the arrow in Fig. 1. Positioned generally intermediate between the stationary table T and the feeder 21 is a shearing unit 22 including a fixed or upper blade 22A and a movable or lower blade 22B. Positioned upstream of the feeder 21 is an uncoiler 23 including a drum 24 carrying the continuous composite strip AS coiled around the drum 24. As hereinbefore discussed, the composite strip AS is a laminated strip including a plurality of elongated plies of amorphous magnetic metal alloy. This feeder 21 may be of any known construction including a feed roller 21A adapted to be driven by a suitable drive mechanism (not shown) and a pinch roller 21B displaceable between a pinching position, in which the pinch roller 21B is brought into contact with the feed roller 21A to feed the composite strip AS therethrough, and a retracted position in which the pinch roller 21B is separated from the feed roller 21 A. When the pinch roller 21B is in the pinching position, the continuous composite strip AS is therefore drawn from the uncoiler 23 and then fed towards the stationary table T past the feeder 21. First and second sliders SL1 and SL2 are supported in position above the stationary table T for reciprocating movement in a direction lengthwise of the stationary table T, that is, in a direction conforming to the direction of feed of the continuous composite strip AS without being interfered with each other. These first and second sliders SL1 and SL2 are drivingly coupled with a drive mechanism including first and second ball-and-screw feeders BS1 and BS2 so that they can be moved reciprocately in the direction lengthwise of a stationary frame structure. First and second movable plates M1 and M2 are supported respectively by the first and second sliders SL1 and SL2, respectively, and have the first and second strip feed clamps SF1 and SF2 fitted thereto for clamping a leading end of the continu¬ous composite strip AS in cooperation with the first and second movable plates M1 and M2, respectively. The first and second stepwise shift clamps SC1 and SC2 are support¬ed below the stationary table T by the first and second sliders SL1 and SL2 and are operable to clamp the composite strip on the stationary table T from below in cooperation with the first and second movable plates M1 and M2 through respec¬tive slots defined in the stationary table T. First and second tail clamps TC1 and TC2 for clamping the composite strip on the stationary table T in cooperation with the stationary table T at a location adjacent the shearing unit 22 are disposed in the vicinity of the trailing end 20a of the stationary table T. It is to be noted that the stationary table T, the feeder 21, shearing unit 22, sliders SL1 and SL2, movable plates M1 and M2, the strip feed clamps SF1 and SF2, the stepwise shift clamps SC1 and SC2, the tail clamps TC1 and TC2, and a control unit (not shown) for controlling them constitute a strip stacking apparatus 31 of the present invention. A winding unit 32 is positioned downstream of a leading end 20b of the stationary table T, onto which the stacked strip blocks Bn (n = 1,2, 3, ) which have been successively formed by the strip stacking apparatus are succes¬sively supplied as will be described later. The illustrated winding unit 32 includes a rotatably supported mandrel M, a generally endless belt V trained around a plurality of pulleys P with a portion turned around the mandrel M to form a loop therearound and a drive mechanism (not shown) for driving the endless belt so that the stacked strip blocks B-|, B2, can be successively turned around the rotary mandrel M and inwardly of that portion of the endless belt V extending around the rotary mandrel M to form the cylindrical core of the structure shown in Fig. 13. Although in the illustrated embodiment the rotary mandrel M is shown to be cylindrical in shape, a generally rectangular-sectioned or square-sectioned rotary mandrel may be employed if the rectangular-sectioned or square-sectioned hollow core of the structure shown in Fig. 14 is desired to be manufactured, respectively. The details of the strip stacking unit of the present invention will now be described with particular reference to Figs. 2 to 7. As best shown in Figs. 2 and 3, the stationary frame structure referred to above is identified by 41 and is supported on a support base 40. This stationary frame structure 41 includes a support column 42 fixed at a lower end to the sup¬port base 40 as shown in Fig. 3, a transverse frame 43 fixed at one side to an upper end of the support column 42 so as to extend in a direction transverse to the stationary table T while overlaying the latter. The stationary table T comprises a plurality of, for example, three, generally elongated, rectangular table segments 20 laid in the same plane so as to extend in a direction conforming to the direction of feed of the composite strip AS. Those table segments 20 are fixedly mounted on respective support frames 44 extending lengthwise of the associated table seg¬ments 20 and having legs fixed to the support base 40. The table segments 20 are spaced from each other in a sidewise direction thereof so as to define first and second slots 45A and 45B as best shown in Figs. 3 and 5. The transverse frame 43 has an undersurface to which first and second guide rails 46A and 46B are secured so as to extend parallel to each other in a direction lengthwise of the stationary table T. Each of the first and second guide rails 46A and 46B has a generally dovetailed shape in section and is slidingly received in a correspondingly dovetailed guide groove defined in each of the first and second sliders SL1 and SL2. The first and second guide rails 46A and 46B make it possible for the first and second sliders SL1 and SL2 to move relative to the first and second guide rails 46A and 46B in the direction lengthwise of the stationary table T (or lengthwise of each of the slots 45A and 45B) guided respectively by the first and second guide rails 46A and 46B. Each of the first and second sliders SL1 and SL2 has defined therein an internally threaded hole extending in a direction conforming to the direction of feed of the composite strip with the associated ball-and-screw feeder BS1 or BS2 threadingly received therein. The ball-and-screw feeder BS1 and BS2 are in turn drivingly coupled with respective output shafts of separate servo-motors (not shown) so that the first and second sliders SL1 and SL2 can be reciprocately moved by those servo-motors along the ball-and-screw feeders BS1 and Bs2. First and second clamp lift cylinders 47A and 47B, each of which may preferably be a pneumatically operated cylinder, are fitted to respective undersur-face of the first and second sliders SL1 and SL2. The lift cylinders 47A and 47B include respective piston rods 47a and 47b having their lower ends to which the associated first and second movable plates M1 and M2 carrying the first and second strip feed clamps SF1 and SF2 are secured. Generally rectangular side frames 50A and 50B have their upper ends fixed to outer side faces of the first and second sliders SL1 and SL2, respectively, and also have their lower ends coupled respectively to first and second wheeled carriages 51A and 51B each including a caster 52A and 52B. The casters 52A and 52B of the first and second wheeled carriages 51A and 51B are received in and guided along first and second guide rails 53A and 53B fixedly mounted on the support base 40 so as to extend below and along the slots 45A and 45B in the stationary table T. The first and second stepwise shift clamps SC1 and SC2 referred to above are fixedly mounted on the first and second carriages 51A and 51 B, respectively. In the structure so far described, when the first slider SL1 is driven, the first movable plate M1 and the first carriage 51A move together with the first slider SL1, causing the first strip feed clamp SF1 and the first stepwise shift clamps SC1 to move in a direction conforming to the direction of feed of the composite strip. Similarly, when the second slider SL2 is driven, the second movable plate M2 and the second carriage 51B move together with the second slider SL2, causing the second strip feed clamp SF2 and the second stepwise shift clamps SC2 to move in a direction conforming to the direction of feed of the composite strip. The component parts that move in the direction conforming to the direction of feed of the composite strip together with the first slider SL1 when the latter is driven are best shown in Fig. 4. In this example, the first movable plate M1 is so shaped as to represent a generally L-shaped configuration when viewed from top, having short and long arms perpendicular to each other with the short arm coupled with the piston rod 47a of the lift cylinder 47A. The long arm of the first movable plate M1 extends in a direction conforming to the direction of feed of the composite strip with a trailing end M1 a thereof oriented towards the feeder 21. A portion of the long arm of the first movable plate M1 adjacent the trailing end M1a thereof is so chamfered as to provide a tapered face M1t for guiding the leading end of the composite strip AS, fed from the feeder 21, so as to ride over onto the first movable plate M1. A pneumatically operated cylinder 54 having a piston rod 54a is fixedly mounted on the first movable plate M1 with the piston rod 54a oriented along the long arm thereof towards the trailing end M1a thereof. A drive member 55 is fixedly mounted on a free end of the piston rod 54a and is formed with a cam face 55a that is downwardly inclined towards the first movable plate M1 for driving the first strip feed clamp SF1. At a portion generally intermediate between the drive member 55 and the trailing end M1 a of the first movable plate M1, a pair of brackets 56 are fixedly mounted for pivotally supporting a generally elongated clamp plate 57 by means of a pivot pin extending completely across the width thereof with its opposite ends received by the respective brackets 57. The clamp plate 57 has a generally U-shaped leading end and a trailing end opposite to each other. While the trailing end 57a of the clamp plate 57 is bent downwardly so as to converge with the movable plate M1, the U-shaped leading end of the cam plate 57 has a roller 58 mounted rotatably thereon and the cam plate 57 is normally biased by a suitable biasing means (not shown) such as, for example, a spring element to cause the roller 58 to rest on the cam face 55a of the drive member 55. It is to be noted that in the illustrated embodiment the air cylinder 54, the drive member 55, the clamp plate 57 and the roller 58 altogether constitute the first strip feed clamp SF1. This first strip feed clamp SF1 operates in such a manner that when the air cylinder 54 is actuated with the piston rod 54a consequently moved to an extended position, the cam face 55a of the drive member 55 raises the roller 58, accompanied by a pivotal movement of the clamp plate 57 in a clockwise direction about the pivot pin as viewed in Fig. 4. This clockwise movement of the clamp plate 57 results in displacement of the trailing end 57a of the clamp plate 57 towards the movable plate M1 to thereby clamp a laminated structure of the com¬posite cut strips between the trailing end 57a of the clamp plate 57 and the movable plate M1. On the other hand, when the air cylinder 54 is actuated with the piston rod 54a moved to a retracted position, the cam face 55a of the drive member 55 withdraws from the roller 58, allowing the clamp plate 57 to pivot counterclockwise by the effect of the biasing means. This counterclockwise movement of the clamp plate 57 results in separation of the trailing end 57a of the clamp plate 57 away from the movable plate M1 to thereby release the laminated structure of the composite cut strips. A pneumatically operated cylinder 60 having a piston rod 60a is fixedly mounted upright on the first carriage 51A with the piston rod 60a oriented upwardly and is so positioned relative to the stationary table T that when the air cylinder 60 is actuated with the piston rod 60a consequently moved to an extended position, the piston rod 60a can move upwardly through the first slot 45A defined between the neighboring table segments 20 with a free end thereof brought into contact with the undersurface of the laminated structure of the composite cut strips, then resting on the stationary table T, to cause the laminated structure to be clamped between it and the movable plate M1. In the illustrated embodiment, the air cylinder 60 including the piston rod 60a constitutes the first stepwise shift clamp SC1. Although in the foregoing description, the component parts that move in the direction conforming to the direction of feed of the composite strip together with the first slider SL1 when the latter is driven have been discussed, component parts that move in the direction conforming to the direction of feed of the compo¬site strip together with the second slider SL2 are of a structure substantially identical with those movable together with the first slider SL1, it being, however, to be noted that the second movable plate M2 and the second carriage 51B both movable together with the second slider SL2 are disposed in a symmetrical relation with the first movable plate M1 and the first carriage 51A movable together with the first slider SL1 with respect to the longitudinal axis of the intermediate table segment 20. More specifically, as shown in Fig. 7, the second strip feed clamp SF2 mounted on the second movable plate M2 is, as is the case with the first strip feed clamp SF1, comprised of a pneumatically operated cylinder 54, a drive member 55, a clamp plate 57 and a roller 58 and is operable to clamp the leading end of the composite sheet AS between the clamp plate 57 and the second movable plate M2. Also, the second stepwise shift clamp SC2 mounted on the second carriage 51 B is, as is the case with the first stepwise shift clamp SC1, constituted by a pneumatically operated cylinder 60 having a piston rod 60a that can move upwardly through the second slot 45B defined between the neighboring table segments 20 of the stationary table T to clamp the laminated structure of the composite cut strips, then resting on the stationary table T, between it and the second movable plate M2. The first and second tail clamps TC1 and TC2 are positioned on res¬pective sides of the stationary table T at a location generally intermediate between the shearing device 22 and the first and second strip feed clamps SF1 and SF2 as shown in Fig. 5 although the second strip feed clamp SF2 is not shown therein. Each of the first and second tail clamps TC1 and TC2 comprises a pneumatically operated cylinder 62 having a piston rod 62a and mounted on a carrier plate 61, secured to the undersurface of the stationary table T, with the piston rod 62a oriented upwardly, a clamp arm 63 having a free end 63a bent to form a hook and having an opposite end mounted on a free end of the air cylinder 62, a stopper pin 64 fixedly mounted upright on the associated stationary table segment 20, and any suitable rotating means (not shown) for rotating the clamp arm 63. This rotating means may, for example, comprise a rotary member splined to the piston rod 62a in a manner permitting the piston rod 62a to move axially relative to the clamp arm 63, and a drive mechanism for driving the rotary member. The stopper pins 64 of the respective first and second tail clamps TC1 and TC2 are spaced a distance substantially equal to the width of the composite strip AS so that the composite strip AS when received in between those stopper pins 64 can be properly positioned relative to the stationary table T. The first and second tail clamps TC1 and TC2 are utilized to clamp respective tail portions (trailing ends) of the composite cut strips then stacked on the stationary table 20 to thereby avoid any possible lateral displacement of the composite cut strips as the composite strip AS is pulled onto the stationary table T by the strip feed clamps SF1 and SF2 then clamping the leading end of such composite strip AS. It is to be noted that the manner in which the continuous composite strip AS to be cut or sheared by the shearing unit 22 to provide the composite cut strips S is pulled onto the stationary table with its leading end clamped by the first or second strip feed clamps SF1 and SF2 as the associated first or second sliders SL1 and SL2 is driven in a direction away from the shearing unit 22 will be herein¬after referred to as "pull-feed". Thus, that the continuous composite strip AS to be sheared is "pull-fed" means that such continuous composite strip AS is pulled onto the stationary table with its leading end clamped by the first or second strip feed clamps SF1 and SF2 as the associated first or second sliders SL1 and SL2 is driven in a direction away from the shearing unit 22. When the composite strip AS is to be pull-fed while no composite cut strip S exist on the stationary table T, that is, while the stationary table T is vacant, the clamp arms 63 of the respective tail clamps TCI and TC2 are held in a retract¬ed position as shown in Fig. 5 clearing from the composite strip AS to be sheared or being sheared by the shearing unit 22. When the composite sheet S is to be clamped by the first and second tail clamps TC1 and TC2 in cooperation with the stationary table T (specifically, the outside table segments 20 adjacent the first and second tail clamps TC1 and TC2), the air cylinders 62 have to be actuated with the piston rods 62a consequently moved to an extended position to lift the respective clamp arms 63 to a level sufficient to form a predetermined gap above the level of the stationary table T, followed by rotation of the clamp arms 63 until the clamp arms 63 are brought into engagement with the associated stopper pins 64. After the clamp arms 63 have been engaged with the respective stopper pins 64, the air cylinder 62 are again actuated to retract the associated piston rods 62a to a clamp position at which the composite cut strip S can be clamped between the stationary table segments 20 and the clamp arms 63 as shown in Fig. 6. Referring to Fig. 2, the feeder 21 includes the feed roller 21A engage-able from below with the composite strip AS and the pinch roller 21B positioned above the feed roller 21A and secured to a lower end of a piston rod 70a of a pneumatically operated cylinder 70. This pinch roller 21B is adapted to be driven by the air cylinder 70 between the pinching position, in which the pinch roller 21B is brought into contact with the feed roller 21A to feed the composite strip AS therethrough, and the retracted position in which the pinch roller 21B is separated from the feed roller 21 A. Positioned between the feeder 21 and the shearing unit 22 is a delivery table 78 for the support of the composite strip AS being fed towards the shearing unit 22. In the illustrated embodiment, the control unit (not shown) is utilized to control the feeder 21, the first and second strip feed clamps SF1 and SF2, the first and second stepwise shift clamps SC1 and SC2, the first and second tail clamps TC1 and TC2 and the shearing unit 22 in a predetermined sequence. This control unit may comprise a microcomputer, in which case the microcomputer may execute such an algorithm as shown in Figs. 9 to 12. A sensor for measuring the thickness of the continuous composite strip AS fed from the feeder 21 is also employed so that an output signal from this sensor which is indicative of the thickness of the continuous composite strip AS detected can be supplied to the control unit. The strip stacking method executed by the strip stacking apparatus of the structure described hereinbefore will now be described with particular reference to Figs. 8 to 12. The continuous composite strip which may be of a laminar structure of a plurality of, for example, eight, elongated plies of amorphous magnetic metal alloy is wound around the drum 24 of the uncoiler 23. In the following description of the operation of the strip stacking apparatus, it is assumed that the continuous composite strip AS is cut into the composite cut strips S by the shearing unit 22, every four composite cut strips being subsequently stacked one above the other to provide a single multilayered strip. Thus, the single multilayered strip includes a laminar structure of 32 plies of amorphous magnetic metal alloy that have been cut into oblong pieces. Referring first to Fig. 9, when the microcomputer (not shown) is powered on with a START command, initialization takes place at step 0. During the initialization, respective controls for controlling the first and second sliders SL1 and SL2 are given a return-to-origin command by which the first and second sliders SL1 and SL2 are moved in a direction away from the shearing unit 22 to bring the first and second strip feed clamps SF1 and SF2 to an initial position. This initial position for the first and second strip feed clamps SF1 and SF2 is defined at a location spaced from the shearing unit 22 a distance sufficient to avoid interference of any one of the first and second strip feed clamps SF1 and SF2 with the pull-feed of the continuous composite strip AS. Subsequent to the initialization, and at step 1, the initial length L-| to which the continuous composite strip AS is cut (and, hence, the length of the first multilayered strip U-j), the shift distance La by which the multilayered strips are displaced lengthwise thereof, the number NS of the composite cut strips that form a single multilayered strip, the number NB of the multilayered strips that form a single stacked strip block, and the number Ts of the stacked strip blocks that form the cylindrical core are read in. As assumed in this example, the number NS of the composite cut strips that form the single multilayered strip is set to be 4, and accordingly, the single multilayered strip includes a laminar structure of 32 strips of amorphous magnetic metal alloy that have been cut into oblong pieces. After the parameters L-|, La, NS, NB and Ts have been read in, the first slider SL1 is driven towards the shearing unit 22 to bring the first strip feed clamp SF1 to the clamp position adjacent the shearing unit 22 at step 2. Simulta¬neously therewith, the feeder 21 is activated to advance the continuous composite strip AS onto the stationary table T through a cutting area between the fixed and movable blades 22A and 22B of the shearing unit 22 at step 3. When the leading end of the continuous composite strip AS arrives at the clamp position of the first strip feed clamp SF1, the feeder 21 is halted or deactivated. Then, the first strip feed clamp SF1 is moved a slight distance towards the shearing unit 22 to allow the leading end of the continuous composite strip AS to be received in between the clamp plate 57 of the first strip feed clamp SF1 and the associated movable plate M1 as shown in Fig. 8(A) and the air cylinder 54 of the first strip feed clamp SF1 is actuated to cause the first strip clamp SF1 to clamp the leading end of the continuous composite strip AS at step 4. After the leading end of the continuous composite strip AS has been clamped by the first strip clamp SF1, the pinch roller 21 B of the feeder 21 is moved to the retracted position to release the continuous composite strip AS which has been pinched between it and the feed roller 21A at step 5, followed by movement of the first slider SL1 towards a position downstream of the stationary table T to thereby move the first strip feed clamp SF1 towards the leading end 20b of the stationary table T as shown in Fig. 8(B). In this way, the continuous composite strip AS is pull-feed at step 6 such a distance that the distance between the leading end of the continuous composite strip AS and a plane in which the fixed and movable blades 22A and 22B lies may attains the preset length of the multilayered strip. During this time, while the movable plate M2 is elevated, the second slider SL2 is driven towards the shearing unit 22 to move the second strip feed clamp SF2 to the clamp position at step 7. The distance over which the continuous composite strip AS is feed at step 6 can be detected by measuring the number of revolution of the servo-motor for driving the ball-and-screw feeder BS1. Alternatively, the use may be made of a roller frictionally engaged with the continuous composite strip for rotation together with movement of the continuous composite strip, in combination with a sensor for detecting the distance of feed of the continuous composite strip in terms of the number of revolutions of the roller. When after initiation of the pull-feed of the continuous composite strip AS it is detected that the distance between the blades of the shearing unit 22 and the leading end of the continuous composite strip on the stationary table T attains a value equal to the preset length of the multilayered strip, the first slider SL1 is brought to a halt and, as shown in Fig. 8(C), the movable blade 22B of the shearing unit 22 is lowered to cut the continuous composite strip AS at step 8 to thereby provide the composite cut strip S resting on the stationary table T. Thus, the count ns of a sheet counter is incremented by 1 at subsequent step 9. Referring to Fig. 10, and at step 10, a decision is made to determine if the count ns of the sheet counter attains a value equal to the preset number NS. Should the decision at step 10 indicate that the count ns of the sheet counter has not yet attained the value equal to the preset number NS, the first and second tail clamps TC1 and TC2 are activated at step 11 to clamp the trailing end of the composite cut strip S, then cut from the continuous composite strip AS, against the stationary table T as shown in Fig. 8(C). The program flow then goes to step 23 shown in Fig. 11 at which the first strip feed clamp SF1 is held in an unclamp position and is, at the same time, advanced in a direction conforming to the direction of feed as shown in Fig. 8(D), followed by a release of the composite cut strip S from the first strip feed clamp SF1. During this time, feed of the continuous composite strip AS by the feeder 21 is initiated at step 24 and, simultaneously therewith, the second strip feed clamp SF2 is moved to the clamp position at step 25 in readiness for the next cycle of pull-feed. This condition is also shown in Fig. 8(D). When the leading end of the continuous composite strip AS arrives at the clamp position of the second strip feed clamp SF2, the feeder 22 is brought to a halt. Thereafter, while the movable plate M2 of the second strip feed clamp SF2 is lowered, the second strip feed clamp SF2 is moved towards the shearing unit 22. After as shown in Fig. 7 the leading end of the continuous composite strip AS has been received in between the clamp plate 57 of the second strip feed clamp SF2 and the associated movable plate M2, the air cylinder 54 of the second strip feed clamp SF2 is actuated to cause the second strip feed clamp SF2 to clamp the leading end of the continuous composite strip AS at step 26, followed by release of the continuous composite strip AS from the feeder 21 at step 27. Thereafter, as shown in Fig. 8(E), while the movable plate M1 is elevated, the first strip feed clamp SF1 is moved to the clamp position at step 28 and, at the same time, the second strip feed clamp SF2 is moved downstream with respect to the direction of feed to pull-feed the composite strip AS at step 29. This pull-feed operation by the second strip feed clamp SF2 is substantially similar to that accomplished by the first strip feed clamp SF1. After completion of the pull-feed of the continuous composite strip AS, the movable blade 22B of the shearing unit22 is lowered to cut the continuous composite strip AS at step 30 to provide the second composite cut strip S which subsequently falls onto the stationary table T. The count ns of the sheet counter is then incremented by 1 again at step 31. At subsequent step 32, a decision is made to determine if the count ns of the sheet counter has attained a value equal to the preset number NS. Should the decision at step 32 indicate that the count ns of the sheet counter has not yet attained the value equal to the preset number NS (and is hence smaller than the preset number NS), the first and second tail clamps TC1 and TC2 are activated at step 33 to clamp the respective trailing ends of the first and second composite cut strips S against the stationary table T at step 33. Then at step 34, the second strip feed clamp SF2 is held in an un-clamp position and is, at the same time, advanced in a direction conforming to the direction of feed, followed by a release of the second composite cut strip S from the second strip feed clamp SF2. Simultaneously therewith, the program flow returns to step 2, shown in Fig. 9, at which the first strip feed clamp SF1 is moved to the clamp position and, after the movable plate M1 has been lowered, feed of the continuous composite strip AS by the feeder 21 is again initiated at step 3. By repeating the flow from step 1 to step 34, the composite cut strips S in a number equal to the preset number NS are successively stacked one above the other on the stationary table T as shown in Fig. 8(F). However, should the decision at step 10 shown in Fig. 10 indicate that the count ns of the sheet counter has attained a value equal to the preset number NS, signifying that a single multi-layered strip has been completed, the count nb of a stack counter is incremented by 1 at step 13 and the cut length (the length of each composite cut strip which is in turn equal to the length to which the composite strip is pull-fed) is incremented by 2/rt (t representing the thickness of the single multilayered strip) at step 14. The thickness of the single multilayered strip can be calculated by detecting an average value of respective thicknesses of the composite strips measured succes¬sively at a particular location, for example, at a location generally intermediate between the shearing unit22 and the feeder 21 and then multiplying this average thickness by the number NS of the composite cut strips S that form the single multilayered strip. At subsequent step 1 5, another decision is made to determine if the count nb of the stack counter has attained a value equal to the preset number NB of the multilayered strips that form a single stacked strip block. If the decision at step 1 5 indicates that the count nb has not yet attained the value equal to the preset number NB, that is, nb smaller than NB, a stepwise shift process is carried out at step 16. This stepwise shift process is carried out in such a manner that as shown in Fig. 8(G), while the uppermost one of the composite cut strips stacked one above the other on the stationary table T is clamped by the first strip feed clamp SF1, the air cylinder 60 forming a part of the stepwise shift clamp SC1 is actuated to drive the piston rod 60a to the extended position to cause the stack of \ the multilayered strips and, hence, the stacked strip block, to be clamped in cooperation with the movable plate M1, followed by movement of the first slider SL1 a distance equal to the shift distance La downstream in a direction conforming to the direction of feed. The program flow then goes to step 11 at which the first and second tail clamps TC1 and TC2 are held in a clamp position. On the other hand, if the decision at step 15 indicates that the count nb has attained the value equal to the preset number NB indicating that as shown in Fig. 8(H), the single stacked strip block comprised of the multilayered strips U-i to Ug is completed, the count nb of the stack counter is reset to zero at step 17, followed by execution of the nest process step at step 18 and, after incrementing ts by one at step 19, by the subsequent decision at step 20 at which a decision is made to determine if the count ts of the stacked strip blocks has attained a value equal to the preset value Ts. Should the decision at step 20 indicate that the count of the stacked strip blocks Bn has not yet attained the value equal to the preset value Ts, the program flow goes to steps 23, 24, and 25 shown in Fig. 11. On the other hand, should the decision at step 20 indicate that the count of the stacked strip blocks Bp has attained the value equal to the preset value Ts indicating that formation of the stacked strip blocks in a number required to form the single cylindrical core has completed, after resetting ts to zero at step 21, the apparatus is halted at step 22. Similarly, when the decision at step 32 shown in Fig. 12 indicates that the count ns of the sheet counter has attained the value equal to the preset value NS, the count nb of the stack counter is incremented by 1 at step 36 and the cut length is then incremented by 1 at step 37. Thereafter, a further decision is made at step 38 to determine if the count nb of the stack counter has attained the value equal to the preset value NB, that is, the number of the multilayered strips forming the single stacked strip block. Should the decision indicates that the count nb has not yet attained the value equal to the preset value NB, that is, the count nb smaller than the preset value NB, the stepwise shift process is carried out at step 39. This stepwise shift process is carried out in such a manner that as shown in Fig. 8(G), while the uppermost one of the composite cut strips stacked one above the other on the stationary table T is clamped by the first strip feed clamp SF2, the air cylinder 60 forming a part of the stepwise shift clamp SC2 is actuated to drive the piston rod 60a to the extended position to cause the stack of the multilayered strips and, hence, the stacked strip block, to be clamped in cooperation with the movable plate M2, followed by movement of the first slider SL2 a distance equal to the shift distance La downstream in a direction conforming to the direction of feed. The program flow then goes to step 33 at which the first and second tail clamps TC1 and TC2 are held in a clamp position. On the other hand, if the decision at step 38 indicates that the count nb has attained the value equal to the preset number NB, the count nb of the stack counter is reset to zero at step 40, followed by execution of the nest process step at step 42 and, after incrementing ts by one at step 41, by the subsequent decision at step 43 at which a decision is made to determine if the count ts of the stacked strip blocks has attained a value equal to the preset value Ts. Should the decision at step 42 indicate that the count of the stacked strip blocks Bp has not yet attained the value equal to the preset value Ts, the program flow goes to steps 2 and 3 shown in Fig. 9. On the other hand, should the decision at step 43 indicate that the count of the stacked strip blocks Bp has attained the value equal to the preset value Ts, that is, when it is determined that the required count of the stacked strip blocks necessary to form the complete cylindrical core have been formed, after resetting ts to zero at step 44 the apparatus is halted at step 45. The next process step referred to as executed at each of steps 1 8 and 42 is, in the illustrated embodiment, a winding process performed by the winding unit 32 shown in Fig. 1, during which the complete stacked strip blocks B are drawn in between the endless belt V and the mandrel M to join the opposite ends of the stacked strip blocks Bn to form a stepped scarf joint in the complete cylindrical core. Thus, according to the present invention, the program algorithm executed by the microcomputer not shown is so designed and so tailored as to alternately and cyclically perform both of the multilayered strip forming process to stack the plural multilayered strips Un one above the other on the stationary table and the stepwise shift process of successively feeding the multilayered strips, which have been stacked one above the other on the stationary table, in the direc¬tion downstream of the direction of feed so as to displace them by the shift distance La relative to each other while the multilayered strips are alternately clamped by the first and second stepwise shift clamps SC1 and SC2, until the stacked strip blocks are formed. The multilayered strip forming process referred to above is carried out by alternately executing first and second composite cut strip forming steps a required number of times sufficient to form a required number of the composite cut strips necessary to complete the single multilayered strip. This first composite cut strip forming step is carried out by feeding the continuous composite strip AS through the cutting gap between the fixed and movable blades 22A and 22B of the shearing unit 22 until the leading end of the continuous composite strip AS arrives at the clamp position, clamping the leading end of the continuous composite strip AS by means of the first strip feed clamp SF1, moving the first strip feed clamp SF1 a predetermined distance downstream with respect to the direction of feed of the continuous composite strip AS while the leading end of the continuous com¬posite strip AS then released by the feeder 21 has been clamped by the first strip feed clamp SF1, and cutting the continuous composite strip AS by means of the shearing unit 2 to provide the single composite cut strip S. The second composite cut strip forming step is substantially similar to the first composite cut strip forming step, but differs therefrom in that the second > strip feed clamp SF2 is utilized. More specifically, the second composite cut strip forming step is carried out by feeding the continuous composite strip AS through the cutting gap between the fixed and movable blades 22A and 22B of the shearing unit 22 until the leading end of the continuous composite strip AS arrives at the clamp position, clamping the leading end of the continuous composite strip AS by means of the second strip feed clamp SF2, moving the second strip feed clamp SF2 a predetermined distance downstream with respect to the direction of feed of the continuous composite strip while the leading end of the continuous composite strip AS then released by the feeder 21 has been clamped by the second strip feed clamp SF2, and cutting the continuous composite strip AS by means of the shear¬ing unit 2 to provide the additional composite cut strip S. Thus, by alternately repeating the first and second composite cut strip forming steps a predetermined number of times, a predetermined number of the composite cut strips can be stacked one above the other on the stationary table to thereby complete the single multilayered strip. From the foregoing, it is clear that the stacked strip blocks ready to be wound around the rotary mandrel M to form the complete cylindrical core having the stepped scarf joint can be obtained substantially efficiently and accurately. Specifically, according to a broad aspect of the present invention, the use of a single strip feed clamp in combination with a corresponding single step¬wise shift clamp, instead of the use of the two strip feed clamps in combination with the corresponding stepwise shift clamps as discussed above in connection with the illustrated embodiment, is sufficient to accomplish the objective of the present invention. As discussed hereinbefore, whereas the use of the two strip feed clamps in combination with the corresponding stepwise shift clamps requires the two strip feed clamps to be operated alternately as if both hands were alternately used to pull two sheets forwards one at a time, the use of the single strip feed clamp in combination with the corresponding single stepwise shift clamp requires the single strip feed clamps repeatedly operated to accomplish the same object. In any event, the strip stacking method of the present invention may suffice to comprise the steps of feeding a continuous composite strip of amorphous magnetic metal by means of a feeder in one transport direction towards a clamp station past a cutting station where a shearing unit is disposed, until a leading end of the continuous composite strip with respect to the transport direction is clamped by at least one strip feed clamp; while the leading end of the continuous composite strip is clamped by the strip feed clamp, pulling the continuous composite strip a predetermined feed distance along a stationary table positioned on one side of the cutting station downstream with respect to the transport direction; cutting the con¬tinuous composite strip by means of the shearing unit to provide a generally rectangular composite cut strip of a length corresponding to said predetermined feed distance; said pulling and cutting steps being alternately repeated a number of cycles until the composite cut strips corresponding in number to the number of cycles are stacked one above the other on the stationary table to thereby provide a multilayered strip; cyclically repeating the pulling and cutting steps sequentially a number of times until a corresponding number of the multilayered strips are stacked one above the other on the stationary table to thereby provide the stacked strip block, wherein a multilayered strip forming process of forming a plurality of the multilayered strips on the stationary table by cyclically repeating said cyclically repeating step, and a stepwise shift process of clamping a portion of the multi-layered strips by means of at least one stepwise shift clamp in cooperation with a corresponding movable plate means movable along the stationary table and driving the stepwise shift clamp to displace the multilayered strips a predetermined shift distance along the stationary table relative to each other in a direction downstream c of the transport direction each time the multilayered strip is formed, to thereby cause the respective leading ends of the multilayered strips to be progressively stepped, are alternately carried out a predetermined number of cycles until the stacked strip block composed of the plural multilayered strips is formed. Thus, according to a broad aspect of the present invention, the use of a single strip feed clamp in combination with a corresponding single stepwise shift clamp, instead of the use of the two strip feed clamps in combination with the corresponding stepwise shift clamps as discussed above in connection with the illustrated embodiment, is sufficient to accomplish the objective of the present invention. As discussed hereinbefore, whereas the use of the two strip feed clamps in combination with the corresponding stepwise shift clamps requires the two strip feed clamps to be operated alternately as if both hands were alternately used to pull two sheets forwards one at a time, the use of the single strip feed clamp in combination with the corresponding single stepwise shift clamp requires the single strip feed clamps repeatedly operated to accomplish the same object. Although the present invention has been described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims, unless they depart therefrom. 1. A method of making a stacked strip block of amorphous magnetii metal, which method comprises the steps of: feeding a continuous composite strip of amorphous magnetic metal by means of a feeder in one transport direction towards a clamp station past a cutting station where a shearing unit is disposed, until a leading end of the continuous composite strip with respect to the transport direction is clamped by at least one strip feed clamp; while the leading end of the continuous composite strip is clamped by the strip feed clamp, pulling the continuous composite strip a predetermined feed distance along a stationary table positioned on one side of the cutting station downstream with respect to the transport direction; cutting the continuous composite strip by means of the shearing unit to provide a generally rectangular composite cut strip of a length corresponding to said predetermined feed distance; said pulling and cutting steps being alternately repeated a number of cycles until the composite cut strips corresponding in number to the number of cycles are stacked one above the other on the stationary table to thereby provide a multilay-ered strip; cyclically repeating the pulling and cutting steps sequentially a number of times until a corresponding number of the multilayered strips are stacked one above the other on the stationary table to thereby provide the stacked strip block; wherein a multilayered strip forming process of forming a plurality of the multilayered strips on the stationary table by cyclically repeating said cyclically repeating step, and a stepwise shift process of clamping a portion of the multi-layered strips by means of at least one stepwise shift clamp in cooperation with a corresponding movable plate means movable along the stationary table and driving the stepwise shift clamp to displace the multilayered strips a predetermined shift distance along the stationary table relative to each other in a direction downstream of the transport direction each time the multilayered strip is formed, to thereby cause the respective leading ends of the multilayered strips to be progressively stepped, are alternately carried out a predetermined number of cycles until the stacked strip block composed of the plural multilayered strips is formed. 2. The method as claimed in claim 1, wherein said predetermined feed distance the continuous composite strip is pulled is increased stepwise for each cycle of the pulling and cutting steps such that the resultant plural multilayered strips have different lengths. 3. A strip stacking apparatus for making a stacked strip block of amorphous magnetic metal, which comprises: at least one feeder for feeding a continuous composite strip of amorphous magnetic metal in one transport direction towards a clamp station past a cutting station where a shearing unit is disposed, until a leading end of the continuous composite strip with respect to the transport direction is clamped by a strip feed clamp means, said strip feed clamp means being, while the leading end of the con¬tinuous composite strip is clamped by the strip feed clamp means, operable to pull the continuous composite strip a predetermined feed distance along a stationary table positioned on one side of the cutting station downstream with respect to the transport direction; a shearing unit disposed at the cutting station for cutting the continuous composite strip to provide a generally rectangular composite cut strip of a length corresponding to said predetermined feed distance said apparatus comprises a stepwise shift clamp means cooperable with a corresponding movable plate to clamp a portion of the multilayered strips, said stepwise shift clamp means being movable together with the movable plate in a direction downstream of the transport direction to displace the multilayered strips a predetermined shift distance along the stationary table relative to each other in a direction downstream of the transport direction each time the multilayered strip is formed, to thereby cause the respective leading ends of the multilayered strips to be progressively stepped; and a control means for executing the strip stacking method as defined in any one of claims 1 or 2 to thereby complete the stacked strip block. 4. The strip stacking apparatus as claimed in claim 3, wherein said strip feed clamp means comprises first and second strip feed clamps and said stepwise shift clamp means comprises first and second stepwise shift clamps and in that said first and second strip feed clamps are operated alternately the continuous composite strip each time the composite cut strip is formed and said first and second stepwise shift clamps are operated in response to alternate operation of the first and second strip feed clamps. 5. A method of making a stacked strip block of amorphous magnetic metal substantially as herein described with reference to figures 1 - 15 of the accompanying drawings. 6. A strip stacking apparatus for making a stacked strip block of amorphous magnetic metal substantially as herein described with reference to figures 1 - 15 of the accompanying drawings.

Documents:

1646-mas-96 abstract.jpg

1646-mas-96 abstract.pdf

1646-mas-96 claims.pdf

1646-mas-96 correspondence-others.pdf

1646-mas-96 correspondence-po.pdf

1646-mas-96 description (complete).pdf

1646-mas-96 drawings.pdf

1646-mas-96 form-2.pdf

1646-mas-96 form-26.pdf

1646-mas-96 form-6.pdf