METHOD AND DEVICE FOR RELEASING CATHODE PLATES

Abstract: The invention relates to a method and a device for releasing electrolytically deposited cathode plates (3) from each side of a mother plate (1). The characteristic features of the invention are that at least one roller (40A) is pressed to the surface of the deposited cathode plate (3), and that the roller (40A) is moved a distance along the surface of the deposited cathode plate (3) in order to cause the release of the deposited cathode plate (3) from the mother plate (1) at least in the rolled area.

Description: METHOD AND DEVICE FOR RELEASING CATHODE PLATES TECHNICAL FIELD The invention relates to a method and a device for releasing electrolytically deposited cathode plates from each side of a mother plate. BACKGROUND OF THE INVENTION In electrolytical refining of copper and other metals, cathode plates are deposited on each side of mother plates. According to technique used in the past a comparatively thin layer is deposited on the mother plate, so called starting sheets, which may have a thickness up to approximately 1 mm. The starting sheets are stripped form the mother plates and are used in a subsequent stage as cathodes, in order to be coated with more electrolytically deposited metal to full thickness. According to modem technique, however, no starting sheets are produced. Instead, the electrolytically deposited metal is accumulated to the intended full thickness on the original mother plate, which may consist e.g. of stainless acid resistant steel, titanium or other metal, according to so called full deposit technique. Whether it is the question of starting sheet production or of full deposit technique, one has encountered problems in connection with the stripping of the deposited cathode plates from the mother plate. Various methods have been employed, including the application of bending forces, impacts, vibrations, etc., but no ideal method so far has been suggested in prior art. Either the suggested and/or employed methods have not been sufficiently efficient or have caused damages on the mother plates or on other equipment. It therefore exists a need to solve these problems in a better mode than according to the technique of today. BRIEF DISCLOSURE OF THE INVENTION It is the purpose of the invention to solve the above mentioned problems. This can be achieved therein that the invention is characterized by what is stated in the characterizing part of the appending independent claims. Further characteristic features and aspects of the invention are apparent from the sub-claims and from the following description of a preferred embodiment. According to the invention at least one roller is pressed to the surface of the deposited cathode plate and that roller is moved a distance along the surface of the deposited cathode plate. The distance at which the roller will press the cathode plate is between 0 and 50 mm, preferably not more than 15 mm from the upper edge of the cathode plates. The roller pressed against the cathode plate, is moved a distance, the total length of which corresponds to 20 to 100 % of the length of the plate assembly, preferably 40 to 80 % of the length of the plate assembly. The pressing and the movement cause the release of the deposited cathode plate from the mother plate at least in the rolled area. The deposited cathode plate is then completely released from the mother plate in the stripping operation proper. The pressing can be carried out by at least one roller pair with the rollers positioned on the opposite side of the plate assembly. Then the rollers are pressed towards each other with the plate assembly between them and they are syncronously moved a rolling distance in the region of an edge part of the cathode plate. The cathode plates are disengaged from the mother plate at least in that edge portion of the cathode plates. It is also possible to use in accordance with the invention two roller pairs, one pair on one side of the plate assembly and the other at the opposite side of the plate assembly so that the roller pair are moved under pressure in opposite directions from each other. These two roller pairs can also be used so that the roller pairs are moved from each other from the central starting positions in directions towards the outer edges of the plate assembly. BRIEF DESCRIPTION OF THE DRAWINGS In the following description of a preferred embodiment, reference will be made to the accompanying drawings, in which Fig. 1 is a side elevation of the devide according to the preferred embodiment, Fig. 2 is a view along the line π-IH in Fig. 1 , and Fig. 3 is a view along the line DI-III in Fig. 2. DESCRIPTION OF A PREFERRED EMBODIMENT In the drawings, a mother plate is generally designated by numeral 1. The mother plate is secured to a cathode rod 2, which is suspended in a not shown feeder. A metal deposition 3, which is about 3 to 8 mm thick, a so called full deposit cathode, is deposited on each side of the mother plate 1, which is about 3 to 6 mm thick, up to a horizontal edge 6. The plate assembly, consisting of the mother plate and the cathode plates 3 are generally designated 4. Along the side edges, and in the present case also along the bottom edge, there is an edge strip 5, which prevents the electrolytically deposited plates 3 from growing together during the electrolytic operation. The plate assembly 4 is approximately square having a side length of about 1 m. The device shown in the drawings is intended to release the cathode plates initially from the mother plate in a pre-stripping station in an integrated, automatic line for the handling of the plate assemblies 4, of the stripped cathode plates 3, and of the mother plates 1. The complete separation - the stripping - of the cathode plates from the mother plate is intended to be performed in a subsequent station in a way which can be performed according to a technique which may be known per se. The device shown in the drawings is in other words a pre-stripping machine consisting of two units, which are equally but invertedly designed, one on each side of the vertically suspended plate assembly 4, which is moved step-wise forward along a conveying path, the longitudinal direction of which coincides with the side extension of the plate assembly 4. In Fig. 2, the pre- stripping machine is viewed in the conveying direction of the plate assembly. The unit on the right hand side is generally designated A, and the unit on the left hand side is designated B. In the following, only the right hand side unit A will be described more in detail, as the unit B is correspondingly designed and therefore does not require any separate description. The reference numerals for parts belonging to the units A and B have been given the suffixes A and B, respectively. Two outer, vertical posts 10A and 11 A and a central post 12A are mounted on a foundation 9 A. Two horizontal guides, namely a lower guide 13 A and an upper guide 14A extend between the outer posts 10A and 11 A and behind the central post 12A, with reference to Fig. 1. Two slides are slidably mounted on the guides 13A and 14A, namely a left hand slide 15A and a correspondingly, but invertedly designed right hand slide 16 A. The slides 15 A, 16A can be moved on the guides 13 A, 14A between inner starting positions and outer final positions. The slides 15 A, 16A are shown in their final posititons in Fig. 1. A lower hydraulic cylinder 17A having a piston rod 18 A is provided for the movements of the left hand slide 15A along the guides 13A, 14A and for the movements of the right hand slide 16A there is provided an upper hydraulic cylinder 19 A with a piston rod 20 A. The hydraulic cylinders 17A, 19A are mounted on the central post 12A by means of cylinder fastening brackets 21 A and 22 A, respectively, and will in the following be referred to as rolling cylinders. The piston rods 18 A, 20 A are attached to the slides 15A and 16A, respectively. The slides, as the slide 15A, consist of a pair of vertical, parallel plates 24A, 25A, and between these plates a lower and an upper sliding sleeve 26A and 27 A, respectively, which surround the quides 13 A, 14A- Further, a back plate 29A extends between the parallel plates 24A and 25A- On the back plate 29 A, there is a carrier 30A, which has the shape of an upper, horizontal plate fastened through a vertical fastening element 31 A. A lever 32 A is pivotably mounted on the carrier 30A through a pivot 33 A. The lever 32A can be pivoted in a horizontal plane about the centre of rotation 34A of the pivot 33 A. The motion means is a hydraulic cylinder 35 A, in the following referred to as pressing cylinder, which is mounted on a vertical mounting means 36A on the carrier 30A through a hinged sylinder bracket 37A. The piston rod 38A is in its front end pivotably fastened to the lever 32A through a front pivot 39 A. In the free, front end of the lever 32A there is a steel roller 40 A, which can rotate about a vertical centre of rotation 41 A. The above described equipment is operated in the following way. First the slides 15A/15B, 16A/16B are brought back to their central starting positions by means of the rolling cylinders 13A/13B, 14A/14B. The rollers 40A/40B, 41 A/41B (the latter one not shown) are brought back by means of their respective pressing cylinders, such as the pressing cylinders 35A 35B. The positions of the rollers in their starting positions are shown through the rollers 40A' and 41 A' shown through dashed lines in Fig. 1. A plate assembly 4 is entered between on one side the rollers 40A and 41 A, and on the other side the rollers 40B and 41 B . Thereafter, the rollers are brought pairwise towards each other, i.e. rollers 40A and 40B are brought towards each other, and the rollers 41 A and 4 IB are correspondingly brought towards each other by means of their respective pressing cylinders, represented by the hydraulic cylinders 35 A and 35B, and are pressed against the plate assembly 4 under a heavy pressing power at a distance of between 0 and 50 mm, preferably about 15 mm from the upper edge 6 of the cathode plates 3. The distance between the roller pairs, i.e. between on one side the rollers 40A/40B and on the other side the rollers 41 A/41B, is 200 mm in the starting position according to the embodiment. From this starting position, the rollers are moved away from each other, i.e. the rollers 40A/40B are moved to the left with reference to Fig. 1, while the rollers 41A/41B are moved to the right, which is accomplished therein, that the slides, as the slides 15A and 16A, and 15B and 16B (not shown), respectively, are brought from each other by means of the rolling cylinders 17A, 19A and 17B, 19B, respectively, at the same time as the rollers 40A, 40B and 41 A, 4 IB, respectively, are pressed towards each other and against the plate assembly by the pressing cylinders. The rolling distance for each roller pair 40A/40B, and 41A/41B, respectively, according to the embodiment is 300 mm. This is sufficient for causing the cathode plates 3 to be disengaged from the mother plate 1 in the upper part of the plate assembly 4. When the rollers 40A 40B have reached their outer end positions, they are displaced from the plate assembly 4 by means of their respective pressing cylinder, such as the pressing cylinder 35A. The plate assembly 4 with the now initially released cathode plates 3 then is moved further on for complete stripping, and the slides 15A/16A, 15B/16B are returned to the their starting positions.

Claims: CLAIMS 1. Method of releasing electrolytically deposited cathode plate (3) from each side of a mother plate (1), characterized in that at least one roller (40 A) is pressed to the surface of the deposited cathode plate (3), and that the roller (40 A) is moved a distance along the surface of the deposited cathode plate (3) in order to cause the release of the deposited cathode plate (3) from the mother plate (1) at least in the rolled area. 2. Method according to claim 1, characterized in that the roller is pressed against the plate assembly at a distance of not more than 50 mm, preferably not more than 15 mm from the upper edge of the cathode plate. 3. Method according to claim 2, characterized in that the roller pressed against the plate assembly, is moved a distance, the total length of which corresponds to 20 to 100 % of the length of the plate assembly, preferably 40 to 80 % of the length of the plate assembly. 4. Method of releasing electrolytically deposited cathode plate (3) from each side of a mother plate (1), characterized in that from each side of the plate assembly (4) at least one roller (40A) is pressed against the plate assembly and in a direction towards a corresponding roller (40B) on the opposite side of the plate assembly, that the rollers in the at least one roller pair are powerfully pressed towards each other with the plate assembly between them, that they under continued pressure are moved sychronously a rolling distance in the region of an edge part of the cathode plates, wherein the cathode plates are disengaged from the mother plate at least in that edge portion of the cathode plates, and that the rollers thereafter are displaced from the cathode plates, which thereafter are completely released from the mother plate in a subsequent stripping operation. 5. Method according to claim 4, characterized in that the rollers are pressed against the plate assembly at a distance of not more than 50 mm, preferably not more than 15 mm from the upper edge of the cathode plate. 6. Method according to claim 5, characterized in that the rollers pressed against the plate assembly, are moved a distance, the total length of which corresponds to 20 to 100 % of the length of the plate assembly, preferably 40 to 80 % of the length of the plate assembly. 7. Method according to the claim 4, characterized in that two roller pair under pressure is moved in opposite directions from each other. 8. Method according to the claim 7, characterized in that the two roller pairs under pressure are moved from each other from central starting positions in directions towards the outer edges of the plate assembly. 9. Device for releasing electrolytically deposited cathode plates (3) from each side of a mother plate (1), characterized in that at least one roller is provided on one side of the plate assembly, that means are provided for moving the roller, and that motion means are provided to move the roller a distance from the upper edge from the cathode plate, so that the cathode plate is disengaged from the mother plate at least in the region of the upper edge portion of the cathode plate. 10. Device for releasing electrolytically deposited cathode plates (3) from each side of a mother plate (1), characterized in that at least one roller is provided on one side of the plate assembly and the same number of rollers is provided on the opposite of the plate assembly, said rollers on each side of the plate assembly are arranged pairwise opposite each other, that means are provided for moving the rollers in each roller pair towards each other with the plate assembly between them, and that motion means are provided to move the rollers of the roller pairs synchoronously a distance from the upper edge from the cathode plates, so that the cathode plates are disengaged from the mother plate at least in the region of the upper edge portion of the cathode plates. 11. Device according to claim 10, characterized by at least one guide (13A,13B, 14A/14B) extending on each side of the plate assembly (4), at least one slide (15A/15B), 16A/16B) on each guide, motions means (17A/17B, 19A/19B) provided to move the slides on each guide, on each slide a movably mounted roller (40A, 40B) having a vertical axis of rotation, and motion means (35A,35B) provided to move the roller from a rear disengaged position and back to the disengaged position. 12. Device according to any of the claims 10 and 11, characterized in that said motion means which are provided to move the rollers of the roller pairs in opposite directions from each other on each side of the plate assembly. 13. Device according to claim 12, characterized in that the rollers on each side are provided to be moved from other while they are pressing against the plate assembly.

Inventors: SEGERSTROEM KJELL, SEGERSTROEM, KJELL
Applicants: SEGERSTROEM KJELL, WENMEC SYSTEMS AB, SEGERSTROEM, KJELL, WENMEC SYSTEMS AKTIEBOLAG
Application year: 1996
Main classification: C25C7
IPC codes: C25C7