Australian Patents Act 1990 - Regulation 3.2 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention Title Method for stripping electrodeposited metal sheets and flexing device used therein The following statement is a full description of this invention, including the best method of performing it known to me/us: P/00/0 Il C 1 A N-11-176AU Method for stripping electrodeposited metal sheets and flexing device used therein Technical Field The present invention relates to a method for stripping electrodeposited metal sheets and a flexing device used therein, and more specifically to a method for stripping metal sheets electrodeposited on the surfaces of cathode plate by electrolytic smelting and a flexing device used therein. Background of the Invention Electrolytic smelting of metal using permanent cathodes (PC) according to ISA method, for example electrolytic smelting of copper, is performed by electrodepositing electrolytic copper to the opposite surfaces of cathode plates by immersing a plurality of cathode plates made from stainless and anode plates cast with crude copper alternately in a electrolyte cell filled with electrolyte and conducting electricity thereto. Copper electrodeposited on the cathode plates is stripped from the plates using a stripping apparatus and served as products. More specifically, as shown in FIG. 1, a cathode plate 1 is a stainless plate fitted with protectors 5 of synthetic resin on its both lateral sides while having a crossbar 4 provided at its upper side. Said crossbar 4 is further provided with 2 windows 3,3 to which hooks of a cathode plate conveying device (not shown) are latched so as to charge, remove and convey the cathode plate to and from the electrolyte cell. Cathode plates 1 made from stainless are recently being widely used since they are 1 N-11-176AU durable and can be repetitively used while short circuit is less likely to occur during electrolytic smelting due to their good planarity. Then, 2 sheets of electrodeposited metal stripped from either surfaces of the cathode plates are conveyed by a conveying device in pairs, and pressed by a flat press to obtain planarity and further subjected to corrugation to produce wavelike patterns on the electrolytic copper before they are served as products. Conventionally, stripping of electrodeposited metal sheets is performed as disclosed for example in Japanese Patent Publication No. 2006-274299 (Patent Reference 1). More specifically, a cathode plate raised from an electrolyte cell is washed in a cleaning room as it is conveyed, and transferred to a traverse conveyor by transfer equipment. Then, as shown in FIG.2, the cathode plate is retained in an upright state on a base part 120 (refer to FIG.2(a)), and gaps are created in between the cathode plate and the deposited metal sheets by pressing the cathode plate from either sides (so called flexing process) (refer to FIG. 2(b)). In the produced gaps, chisels 35 are inserted (refer to FIG. 2(c)) and driven downward in order to strip the deposited metal sheets 2 from the cathode plate 1 (so called chiseling process), and the stripped metal sheets 2 are removed from the cathode plate 1 by bringing down the metal sheets 2 outwardly on the bottom ends which is contacting the base part 120 (so called downending process) (refer to FIG. 2(d)). In case the deposited metal sheets 2 do not split apart and cannot be separated from the cathode plate 1 by downending, the two elements are separated by performing so called "flapping", in which process the deposited metal sheets 2 are lifted up and pulled down again. 2 N-11-176AU A conventional apparatus as explained above is known for example from Patent Publication No. 2001-81591 (Patent Reference 2). This type of stripping apparatus is comprised of an insulated protector removing device for removing a part of a insulated protector provided on the end part of a cathode plate, chis blades for being inserted in between the electrodeposited metal sheets and the cathode plate which is retained at the set position where the removed part of the insulated protector is arranged, to separate the upper edge of the electrodeposited metal sheets from the cathode plate to form an opened state and a plurality of vacuum suction pads for attaching on to the electrodeposited metal sheets and bringing it downward to the stripping direction. Furthermore, the chis blades are inserted in between the lateral surfaces of the cathode plate and the marginal parts of the electrodeposited metal sheets, and strip the electrodeposited metal sheets from the cathode plate with a wedge action of the wedge-like chis blades to pry open the upper edge of the electrodeposited metal sheets. Then, further stripping of the electrodeposited metal sheets is performed by attaching a plurality of vacuum suction pads to the opened electrodeposited metal sheets and pulling them apart from the cathode plate (so-called flapping). However, in the conventional metal stripping apparatus, due to the flat shape of the base part on which the cathode plate is mounted, when the electrodeposited metal sheets are pulled downward by downending to be stripped from the cathode plate, the maximum angle of electrodeposited metal sheets in relation to the cathode plate was 900. From such configuration, it was sometimes not 3 possible to strip off the electrodeposited metal sheets completely in a single operation. In such case, it was necessary to repeat flapping once or several times more. The electrodeposited metal sheets can be stripped from the cathode plate if the flapping is repeated once or several times, but repetitive flapping means more time is required for the process, which subsequently leads to a decrease in hourly processing amount. More specifically, if the stripping of the electrodeposited metal sheets is done without flapping, it takes about 7 seconds to complete the stripping per plate. Hence, it is possible to perform stripping of 4,000 to 5,000 plates per day in average in about 8 to 10 hours of daily operation. However, if the flapping is repeated several times per each cathode plate, since it takes about 2 seconds to perform 1 flapping in the series of stripping operations, processing amount per day would decrease, which would further influence the operation efficiency. Hence, the present applicant invented and filed the application for an apparatus for stripping electrodeposited metal sheets with protrusions formed on both sides of a base part on which cathode plates are to be mounted, said protrusions being arranged to contact the surfaces of the lower section of said stripped electrodeposited metal sheets when they are pulled down so as the upper ends of said electrodeposited metal sheets are brought down to the level lower than said protrusions to separate the metal sheets from the cathode plates, and thereby completing the series of operation of flexing, chiseling and downending for stripping the electrodeposited metal sheets from a cathode plates in a single operation without performing flapping (Japanese Patent Application No. 2006-266326). 4 N-11-176AU [Patent Reference 1] JP Patent Publication No. 2006-274299 [Patent Reference 21 JP Patent Publication No. 2001-81591 Summary of the Invention Object of the Invention As explained above, it became possible to efficiently strip the electrodeposited metal sheets without performing flapping according to the stripping apparatus invented by the applicant. However, there were cases when the gaps to which the chisels are to be inserted close up due to the electrodeposited metal sheets adhering back onto the cathode plate after openings are formed in between the 2 components, before the chisels are actually inserted to strip off the metal sheets. Such cathode has to be sent back to the flexing process in order to perform chiseling, and this was one of the factors to drop the operation efficiency. Normally, it takes about 7 seconds to complete the stripping of an electrodeposited metal sheet, and according to this data, an average of about 4,000 to 5,000 metal sheets can be stripped and processed in about 8 to 10 hours of daily operation. If more time is spent per a cathode, less quantity would be processed per day, which would naturally influence the operation efficiency. In view of above, it is an object of the present invention to provide a method for stripping electrodeposited metal sheets and a flexing device used therein preventing the electrodeposited metal sheets from adhering back onto the cathode plate to close up the once opened gaps between the metal sheets and cathode plate to ensure 5 C:\NRPortbl\DCC\MDT\2208453_l DOC. a steady insertion of the chisels. Accordingly, in a first aspect the present invention provides a method for stripping electrodeposited metal sheets from a cathode plate, the method comprising: 5 retaining a lower end of the cathode plate electrodeposited with metal sheets and mounted on a base part from either side by lower guides; arranging upper guides at the upper ends of the electrodeposited metal sheets slightly apart from the surfaces of the electrodeposited metal sheets where bending is to be performed; 1o creating gaps in between the electrodeposited metal sheets and the cathode plate by pressing said electrodeposited metal sheets near the center from either side; inserting flexing members into the gaps such that the upper guides act as fulcrums to cause bending of the upper ends of the electrodeposited metal 15 sheets, thereby providing openings between the cathode plate and the electrodeposited metal sheets; and, inserting chisels in the openings between the cathode plate and the electrodeposited metal sheets to strip the electrodeposited metal sheets from the cathode plate. 20 In a second aspect, the present invention provides a flexing device for use in the method for stripping electrodeposited metal sheets according to claim 1 comprising: lower guides for retaining a lower end of the cathode plate electrodeposited with metal sheets and mounted on the base part from either 25 side; upper guides arranged at the upper end of the cathode plate in a 6 C \NR~onb1\DCC\MDT2OS453- I DOC. position slightly apart from the surfaces of the electrodeposited metal sheets where bending is to be performed; pressing members for creating gaps in between said electrodeposited metal sheets and the cathode plate by pressing said electrodeposited metal 5 sheets near the center from either side; and, flexing members for insertion into the gaps such that the upper guides act as fulcrums to cause bending of the upper ends of the electrodeposited metal sheets. Effect of the Invention 10 According to the method for stripping the electrodeposited metal sheets of the present invention, it is possible to insert chisels in between the electrodeposited metal sheets and the cathode plate for sure and chiselling can be performed in a continuous action since the flexing process is provided for bending the upper ends of the electrodeposited metal sheets outward to form s openings between the cathode plate prior to the process of inserting chisels in 7 N-11-1'/6AU between the cathode plate and stripping the electrodeposited metal sheets, to obtain gaps to facilitate insertion of chisels. Furthermore, the method according to the present invention has an effect of maintaining the formed gaps in an opened state by retaining predetermined section of the lower end of said cathode plate electrodeposited with metal and mounted on the base part by lower guides from either side, arranging upper guides along the upper ends of the electrodeposited metal sheets slightly apart from the surfaces of said metal sheets where the bending is to be performed, creating gaps in between said electrodeposited metal sheets and cathode plate by pressing said electrodeposited metal sheets near the center from either side, inserting flexing members into the gaps formed, and thereby bending the upper parts of said electrodeposited metal sheets at said upper guides as fulcrums to obtain gaps to facilitate the insertion of said chisels. As a result, chiseling process can be performed continuously without being suspended. The Preferred Embodiment of the Invention A method for stripping the electrodeposited metal sheets and a flexing device used therein according to the present invention is described in detail hereinbelow with reference to the appended drawings. FIG.3 is a front view of an embodiment of the flexing device according to the present invention, FIG.4 is a side view thereof and FIG.5 is a cross-sectional view of A-A similarly. A flexing device 10 illustrated in the drawings is arranged in the 8 N-11-176AU process prior to the stripping process for stripping electrodeposited metal sheets, and generally comprised to form a frame structure with 4 columns 12 provided on mounts 11 placed on a floor G and traverse bars 13 connecting said columns horizontally, and provided with a base part 20 positioned approximately at the center of said frame, said base part 20 being configured to mount a cathode plate 1 electrodeposited with metal in an upright state thereon. Lower guides 21 are arranged to move horizontally in the drawings by a hydraulic cylinder (not illustrated), and configured to sandwich the lower end of the cathode plate 1 mounted on the base part 20 in between to firmly retain the cathode 1. Above the lower guides 21, pressing members 23 are respectively placed on the left and right side to press near the center of the cathode plate 1 mounted on the base part 20 from either side. As illustrated in FIG. 5, the pressing members 23 are configured to move horizontally by hydraulic cylinders 23a to separate and open the upper parts of the electrodeposited metal sheets 2 from the cathode plate 1 by pressing the cathode plate 1 near the center in order to insert flexing members 29 which will be mentioned later therein. As illustrated in FIG. 5, the pressing members 23 are configured so that their angles relative to the cathode plate 1 mounted on the base part 20 can be adjusted in ±10 in the moving direction. Furthermore, upper guides 25 are arranged respectively on the left and right side above the pressing members 23. The upper guides 25 are configured to move horizontally in FIG. 4 by hydraulic 9 N-11-176AU cylinders (not illustrated), and arranged along the upper end of the cathode 1 mounted on the base part 20 near where bending is to be performed. Flexing is performed by inserting flexing members 29 which will be mentioned later to the formed gaps to let the electrodeposited metal sheets 2 come into contact with the upper guides 25, and thereby bending the upper parts of the metal sheets 2 at the upper guides 25 as fulcrums. With such process, the adherence of electrodeposited metal sheets 2 back onto the cathode plates 1 can be prevented. The flexing members 29 to be inserted in the gaps formed by the pressing members 23 in between the cathode plate 1 and electrodeposited metal sheets 2 are provided on the traverse bar 13 above the base part 20. By inserting the flexing members 29 into the gaps formed by the pressing members 23 between the cathode plate 1 and electrodeposited metal sheets 2, the upper parts of the electrodeposited metal sheets 2 are bent outward at the upper guides 25 as fulcrums, and thereby gaps to facilitate insertion of chisels of a stripping apparatus can be obtained. Thus, troubles of electrodeposited metal sheets 2 adhering back onto the cathode plate 1 and closing up the gaps to which the chisels are inserted can be prevented. The flexing members 29 are fixed to the lower parts of guide bars 29b for guiding vertical movement configured to move up and down by hydraulic cylinders 29a. The flexing members 29 are thereby possible to move up and down. The flexing members 29 are formed in a wedge shape with a cross section of generally right-angled triangle, tapered to be pointed towards the tip, and 10 N-11-176AU configured to bend the upper parts of the metal sheets 2 as they are inserted and pushed down into the gaps between the cathode 1 and metal sheets 2. As the flexing members 29 are used to bend the metal sheets 2, it is preferable that they are made from a rigid material. In the present embodiment, the flexing members 29 are made from SUS304. The operations of the above mentioned flexing device 10 are explained along with a preferable embodiment of the method for stripping electrodeposited metal sheets according to the present invention. FIG. 6 is a schematic side view showing each step of flexing process and. FIG. 7 is a flow chart of a preferable embodiment of the method for stripping electrodeposited metal sheets according to the present invention. First of all, a cathode plate 1 is conveyed to a flexing device 10 by a conveying device (not illustrated) after they are washed in a cleansing room (not illustrated) (Step SO). The cathode plate 1 conveyed to the flexing device 10 is mounted on a base part 20 and retained at its lower end by lower guides 21 from either side (FIG. 6(a)) via hydraulic cylinders (not illustrated) (Step S1). Upper guides 25 are placed at either side along the upper part of the cathode plate 1 where flexing is to be performed via hydraulic cylinders (not illustrated). Then, pressing members 23 are activated by hydraulic cylinders (not illustrated) (FIG. 6(b)) to press the cathode plate 1 near the center alternately from either side (Step S2). The upper edges of the electrodeposited sheets 2 are thereby separated from the cathode plate 1 to form openings. Then, flexing members 29 are 11 N-11- 176AU inserted into the formed openings by shifting guide bars 29b downward by hydraulic cylinder 29a (FIG. 6(c)). Since the flexing members 29 are formed in a wedge shape with a cross-section of generally right-angled triangle tapered to be pointed toward the tip, by inserting and pushing down the flexing members 29 into the openings formed between the electrodeposited metal sheets 2 and cathode plate 1, the upper parts of the electrodeposited metal sheets 2 are forced into contact with the upper guides 25 and bent at the upper guides as fulcrums in the flexing process (Step S3). Thus, adherence of electrodeposited metal sheets 2 back onto the cathode plate 1 can be prevented. The cathode plate done with flexing process is transferred to a stripping apparatus 30 (FIG. 6(d)) to be treated with a series of operations of chiseling and downending (FIG. 6(e)). Since the upper edges of the electrodeposited metal sheets 2 are bent to form openings in the flexing process, chiseling can be performed without any hindrance, and electrodeposited metal sheets 2 can be stripped off from the cathode plate 1 for sure (Step S4). According to the method for stripping electrodeposited metal sheets and the flexing device used therein of the present invention, it is possible to prevent the once separated electrodeposited metal sheets from adhering back onto the cathode plate to close up the openings and block the insertion of the chisels, and thereby chisels can be inserted for sure and chiseling process can be performed continuously without being hindered. The preferable embodiment of the present invention was described hereinabove, but the present invention shall not be limited to the 12 N-I1- 176AU specified embodiment, and should be noted that multiple variations and modifications are possible within the scope of the content of the appended claims. The Brief Description of the Drawings FIG. 1 is a schematic perspective view of a cathode plate with metal deposited on its surfaces. FIG.2 is an explanatory drawing showing the stripping process in a conventional stripping apparatus. FIG.3 is a front view of an embodiment of flexing device according to the present invention. FIG.4 is a side view of the flexing device illustrated in FIG. 3. FIG.5 is a cross-sectional view of A-A of the flexing device indicated in FIG.3. FIG.6 (a)-(e) are explanatory drawings showing each step of the flexing process. FIG.7 is a flow chart of an embodiment of the method for stripping electrodeposited metal sheets according to the present invention. Description of the Numbering 1 cathode plate 13 N-11-176AU 2 electrodeposited metal sheet 3 window 4 crossbar 5 protector 10 flexing device 11 mount 12 column 13 traverse bar 20 base part 21 lower guide 23 pressing member 23a hydraulic cylinder 25 upper guide 29 flexing member 29a hydraulic cylinder 29b guide bar 30 stripping apparatus 35 chisel 36 pressing member 37 gripping member G ground surface 14 C:N RPrIbl\DCC\MDP\2203453 LDOC Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any 5 other integer or step or group of integers or steps. The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or io known matter forms part of the common general knowledge in the field of endeavour to which this specification relates. 14a