AU622994B2 - Electrode handling system and machine - Google Patents

Description

AUSTRALIA

PATENTS ACT 19526 4 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Short Title: Int. Cl: Application Number: Lodged: "Complete Specification Lodged: Accepted: Lapsed: Published: 0 1 Priority: Related Art: Q 0 9 0 0 0 Address of Applicant: -00-200 Granville Street, Vancouver, British Columbia, V6C 2R2, Canada.

Actual Inventors: David Barry Taylor and Kent Edward Smith Address for Service: CALLINAN LAWRIE, 278 High Street, Kew, 3101, Victoria, Australia Complete Specification for the invention entifled: "ELECTRODE HANDLING SYSTEM AND

MACHINE"

performing it known to me:r la ELECTRODE HANDLING SYSTEM AND MACHINE This invention relates to the handling of electrodes and, more particularly, to a method and apparatus for the handling of electrodes in metal electro-deposition processes.

BACKGROUND OF THE INVENTION In metal electrowinning and electrorefining processes, automated handling of electrodes is carried out by an electrode handling machine that is capable of removing sets of selected electrodes from electrolytic cells, and replacing the removed electrodes g1Go with fresh sets. The electrode handling machine is part of a Otoo o, handling system that includes the movement of electrodes between rows of cells and between cells and electrode washing, stripping a and cleaning operations. In most systems the electrodes, 0 0o generally alternating anodes and cathodes appropriately supported on the cell walls, are selectively picked up, transported and released at a desired location and a fresh set is moved back to and set in the cell in the vacated spaces.

SElectrode handling systems, usually including an overhead crane and a grab device for engaging electrodes, with or without means 20 to rotate the device, are disclosed in US Patents 3 562 131, 0 0 3 792 891, 3 887 094, 3 944 088, 4 014 445, 4 392 934 and 4 436 606, and in papers, describing electrolytic deposition processes, such as Erzmetall, Vol. 30, (1977), p. 330-334; Erzmetall, Vol. 34, (1981), p. 387-392; and Journal of Metals, August 1985, p. 47-50. The prior art contains a vast number of 2references to grab devices for engaging objects. Many of the aforesaid patents disclose such devices. In addition, US Patent 4 326 937 is specifically directed to a grab mechanism for electrodes.

Most handling systems include a lifting device, such as a crane, that is installed above the cells and spans a number of parallel rows of cells. Such installation requires provisions for acurately aligning the rails on which the crane moves and for maintaining such alignment. The rails are usually attached to the walls of the cell house at a height substantially above the :0 0 top of the cells. The grab devices are often suspended from the 0000 :oo crane which subject the device to a certain amount of movement.

0000 0 Any movement between building and cells and any movement in the 0*000 osuspension of the grab devices are amplified to the actual grab 0 00 0o150 mechanism that contacts the electrodes causing misalignment between the grab mechanism and the electrodes. Misalignment may cause malfunction or difficulty to the operator in accurately and 000* 0000 quickly picking up from or setting a set of electrodes in a cell.

oo00*0 00 a Misalignment is particularly onerous when an installation 28- includes long rows of cells.

ore Some of the disadvantages of an overhead crane spanning rows of cells are avoided with the apparatus described in US Patent 4 028 211, according to which a low slung bridge straddles one row of cells on rails aligned parallel to the cell walls. A truck moving on rails transverse to the cell rows is adapted to move the bridge from row to row. However, the rails are still 3I attached to a structure separate from the cells, and the electrode carrier is suspended from the bridge by cables. The system is, therefore, subject to movement between structure and cells and to possible misalignment between the grab mechanism and the electrodes. The electrode carrier, i.e. the grab mechanism for the electrodes, is of a complex construction with a plurality of anode clamping rods and cathode clamping units.

SUMMARY OF THE INVENTION We have now found that an electrode handling system that comprises an electrode handling machine wherein the electrode Or S grab means are rigidIyAam-drotatably set on a bridge movable on o tracks attached to the electrolytic cells, substantially eliminates the problem of misalignment and the problems go0 o0 encountered with prior art systems. The grab means comprises a Ao simple grab frame assembly having two longitudinal beams each having two parallel electrode lifter beams capable of selectively engaging or disengaging anodes or cathodes.

ooo o E The electrode handling machine is movable on a pair of tracks Smounted on the opposite side walls of a row of cells in an 0400 arrangement that may comprise a number of parallel rows. Each row comprises a number of electrolytic cells as well as wash and a 0 0 Sdrip cells. One or more anode cleaning machines and cathode stripping machines with feed and discharge conveyors for electrodes may be arranged at the end of the rows. The electrode handling machine can move over the tracks of a row to pick up a set of selected electrodes (anodes or cathodes) by their lifting 4 lugs from a cell, move the set to the wash and drip cells, deliver the set to the conveyors at a cleaning machine or a stripping machine, pick up a cleaned or stripped set of electrodes, and place this set back in a cell. The electrode handling machine can be transferred from row to row over a set of transverse (transfer) tracks. The sequence of all steps is computer controlled.

The electrode handling machine comprises a annular-bridge beam externally supported on two pairs of parallel motor-driven trucks with wheels riding on the parallel tracks on a row of cells.

s Each truck can be swivelled over 900 by a motor-driven turntable oo09 Soo so that the machine may be transferred over the transverse tracks 00oe00 o<oo to the next row at which another turntable for each truck again swivels each 900. The bridge beam carries rotatable or fixed oS Lo bridge frame which in turn supports a vertically-movable electrode grab frame assembly vertically movable relative to the bridge frame. The rotatable bridge frame with grab frame 0°°0°o assembly can be rotated over 1800 to ensure that the grab o mechanism is oriented appropriately in the same direction for engaging cathodes in different rows and that have a movable portion of an edgestick on one side. In an alternative embodiment, the bridge is non-rotatable, and is fixedly attached g to the bridge beam.

The bridge frame has locating means at either end that can fit Opionally into locating brackets on each cell. The bridge frameAhas water spray headers on either side for spraying electrodes being lifted from a cell. The bridge frameAalso has two flexible drip shields that are moved under the electrodes when they are lifted from the cell.

During operation, the electrode handling machine is located (indexed) at a cell from or into which electrodes are removed or set, respectively. To prevent any movement during setting or removing, the machine is located over a cell, the bridge beam with the bridge frame is lowered until the locating means are set in the locating brackets on the cell, and the movement is continued causing the trucks to be lifted off the tracks relative oo to the bridge beam. Raising or lowering is done by the movement of motor-driven hydraulically counterbalanced screws on the oDoe motor-driven trucks.

o o 0 For setting or removing a selected set of electrodes, usually alternate cathodes or alternate anodes, the grab frame assembly is lowered from or raised in the bridge frame by means of 0000 raising/lowering means such as motor-driven chains or lowo friction, roller screws.

os~ The grab frame comprises two parallel, reciprocably movable, grab support beams suspended therefrom by means of two pairs of slider means located at opposite ends of the grab frame assembly.

Attached to each of the grab support beams are two parallel, adjacent electrode lifter beams capable of selectively engaging or disengaging either anodes or cathodes. The two grab support beams with the electrode lifter beams are reciprocably movable ~I I I I 6 over a short distance for indexing to one set or to the other set of alternate cathodes or alternate anodes.

Each electrode lifter beam has a number of corner slots cut-out and spaced along its length at a distance equal to the distance between two adjacent anodes or cathodes, and includes a reciprocable anode or cathode shifter comb. When the grab frame assembly is lowered onto the electrodes, the cathode and anode lifting lugs on the electrode header bars extend into the slots in the respective cathode and anode lifter beams. Each shifter comb is an elongated plate with a number of rectangular lateral a CO protrusions spaced along its length at a distance equal to the a distance between two anodes or two cathodes. By moving the oc~a 00o shifter comb for either a set of anodes or cathodes, the lateral abo protrusions move underneath the top of the lifting lug<, for engagement of a selected set of alternate anodes or alternate cathodes. Upon raising the grab frame assembly, the selected set of electrodes is lifted from the cell.

0400 o o Once the grab frame is in its upper position, the trucks are lowered onto the tracks, the bridge frame is raised and the 0.0.

electrodes handling machine can be moved to a subsequent position.

a O Accordingly, it is an object of the present invention to provide an electrode handling system.

It is another object to provide an electrode handling machine wherein the effects of movement between the system, the electrolytic cells and the machine are essentially eliminated.

It is a further object to provide an electrode handling machine wherein simple electrode grab means substantially eliminate misalignments.

Accordingly, there is provided a system for handling electrodes used in the electro-deposition of metals comprising: a plurality of electrolytic cells arranged in at least one row, each cell containing a multiplicity of electrodes consisting of substantially equi-spaced, alternating anodes and cathodes, each o electrode having an electrode header bar provided with a pair of roo° lifting lugs, each lug comprising a horizontal portion arranged p: such that a horizontal portion of the lifting lugs on the header Ui bars of anodes is oppositely directed to a horizontal portion of the lifting lugs on the header bars of cathodes; an electrode handling machine adapted for moving on parallel tracks mounted o" on opposite sidewalls of the electrolytic cells in a row, said o\ machine having a bridge beam and means for raising and lowering said bridge beam; a bridge frame mounted on said bridge beam) cDi Sad bricdge -Fra4M havi'to loca-1-1y flneasj, q Xgrab frame assembly suspended in said bridge frame and adapted for vertical movement; two parallel grab support beams slidably suspended from said grab frame assembly; an anode lifter beam and a cathode lifter beam attached to each of said grab support beams; each of oaid lifter beams having a number of corner slots corresponding to the number of electrodes in a cell and adapted for receiving the horizontal portion of said lifting lugs fN 8 therein; and a shifter comb in each of said lifter beams adapted to engage a horizontal portion of the lifting lugs of alternate anodes or alternate cathodes.

Accordingly, there is also provided an electrode handling machine used in the electro-deposition of metals in a plurality of substantially rectangular electrolytic cells arranged in a row and having parallel tracks mounted on opposite walls of said cells, each cell containing a multiplicity of electrodes consisting of substantially equi-spaced, alternating anodes and cathodes, each anode having an anode header bar with two spacedapart anode lifting lugs each having a horizontal portion, and 0 0 S each cathode having a cathode header bar with two spaced-apart a o oo, cathode lifting lugs each having a horizontal portion, a o000 .o o horizontal portion of said anode lifting lugs being oppositely directed to a horizontal portion of said cathode lifting lugs; said electrode handling machine comprising a annular vertically movable bridge beam; means for moving said machine on said Scild beridyqe A/o4 6al//1 /6a4 9 /nel'?1S tracks; a bridge frame) supported on said bridge beam; a 00*0 vertically movable grab frame assembly suspended from said bridge frame; two parallel grab support beams slidably suspended from o said grab frame assembly; an anode lifter beam and a cathode lifter beam attached to each of said grab support beams; each of *o 0 said anode lifter beams and each of said cathode lifter beams having a number of equi-spaced corner slots adapted for receiving respectively the horizontal portion of said anode lifting lugs and said cathode lifting lugs; an anode shifter comb in the anode lifter beam for engaging or disengaging a horizontal portion of 9 the anode .lifting lugs of alternate anodes; and a cathode shifter comb in the cathode lifter beam for engaging or disengaging a horizontal portion of the cathode lifting lugs of alternate cathodes.

The objects of the invention and the mannner in which they are realized will become clear from the following detailed description with reference to the accompanying drawings.

Brief Description of the Drawings Figure 1 is a general perspective view of a cell house and the 10 electrode handling machine; 0 00a 0* Figure 2 is a plan view of the electrode handling machine; 0 0 0 00oo Figure 3 is a side view of the electrode handling machine; 0000 o0o 0 Figure 4 is a view of a truck of the handling machine; 0 o0 o°0 Figure 5 A,B,C, and D are schematics showing the position of the 0o 0 electrode handling machine over a cell; Figure 6 is a partial sectional of the electrode handling 0"o machine; o Figure 7 is a perspective view of the grab frame assembly positioned above electrodes in a cell; 0b Figure 8 is a partial perspective detail view of Figure 7 of the electrode lifter beams positioned above electrodes; Figure 9 is a partial perspective detail view of the beams of Figure 8 positioned on anodes in a cell; Figure 10A is a schematic plan view of the shifter comb of Figure 9 in a non-engaging position in a cross section of a lifter beam; ED- I

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Figure 10B is a schematic plan view of the shifter comb of Figure 9 in an alternate, electrode-engaging position in a cross section of a lifter beam; and Figure 11 's a partial cut-away perspective view of the :tuator/limit switch arrangement for the shifter combs c' Figure 8.

Detailed Description With reference to Figure 1, an installation for the electrodeposition of metals such as, for example, zinc, copper, lead and nickel, comprises at least one row 100 of a plurality of adjacent electrolytic cells 101. The cells contain a number of S00 a alternating, substantially evenly-spaced anodes 700 and cathodes 701, each provided with an electrode header bar 702 with anodes a oo o lifting lugs 703 and cathode lifting lugs 704, respectively, by which electrodes may be lifted from the cells (see Figure 7).

The lifting lugs have a suitable shape such as a hook, as shown, or a shape. A horizontal top portion of anode lifting lugs and cathode lifting lugs is directed in opposite direction to facilitate pick-up by a lifting means as shown for hook-shaped 00 anode lugs 703 in Figure 9.

A row of cells 100 comprises electrolytic cells 101 for the electro-deposition of metal and may also comprise at least one electrode wash cell 102 and drip cell 103 usually located at one end of a row. All cells are of conventional construction with rectangular cross sections.

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11 To remove electrodes from or to place electrodes in a cell, an electrode handling machine 104 is used which has moving means adapted to transport the machine on a pair of parallel tracks 105. The tracks 105 are mounted on opposite walls of the cells of each row. The cell-mounted tracks eliminate any movement between building and the electrode handling machine and, in fact, the tracks and cells are integral and independent of the building. Mounting the tracks on the cell walls also eliminates misalignment between electrodes and the machine.

The electrode handling machine 104 may be moved from one row of cells to another row on a pair of parallel transverse tracks 106.

o Tracks 106 are transversely directed to tracks 105 at the end of 0004 the rows 100 of cells 101 and intersect therewith, and are o0 provided with motor-driven turntables 107 at the points of 0 00 150 intersection. The distance between the tracks of a pair of tracks 105 and the tracks of a pair of tracks 106 is the same, and is somewhat greater than the length of a cell 101. Tracks 105 preferably extend over the feed and discharge conveyors of 0000 b0 machines for the stripping of deposited metal from the cathodes 2040 and for the cleaning of anodes (not shown).

4000 When the electrode handling machine 104 is to be moved to another a0 0 row of cells, the machine is moved and located with its moving means, to be described, on the four motor-driven turntables 107 at the end of one row. The turntables 107 are activated to rotate the turntables through an angle of 900, the rotation causing the moving means of the machine to rotate with the OIL._. means for moving said machine on saida tracks; /3 -12- 12 turntables. The machine is then moved over tranverse tracks 106 onto the four turntables 107 at the end of a desired row 100, those four turntables are then activated to turn the moving means through 90", and the machine can be moved on tracks 105 over the cells of that row.

With reference to Figures 2 and 3, the electrode handling machine 104 comprises an annular, vertically movable bridge beam 200. Alternatively, bridge frame 202 is fixedly supported on bridge beam 200, which may have an annular, square, rectangular or other suitable shape. The annulus that forms an annular bridge beam has an essentially rectangular cross section. The top of an annular 4 o1-b, bridge beam 200 is provided with a circular bridge beam track 201 for rotatably Saa supporting a bridge frame, generally indicated with 202. In cases where the o *e a cathodes have a hinged portion of an edgestick to facilitate stripping of deposited metal, it may be necessary to rotate the bridge frame 180 so that cathodes are picked up from and set into cells of different rows with the hinged portion of the °15 edgestick always at the same side of the cathode when being stripped. When rotatably supported, bridge frame 202 is provided with four equi-spaced support wheels 203 (Figure 2) set on circular track 201 on bridge beam 200. Wheels 203 are mounted on the bridge frame at opposite ends of two substantially perpendicular diameters through frame 202. A vertically movable grab frame assembly 204, to be described, is suspended from bridge frame 202. Bridge frame 202 also comprises a power room 205, an electronics room 206 and an air conditioner 207.

1 13 The electrode handling machine 104 is electrically powered, as shown in Figure 3, from a power rail 300 by means of a pantograph 301 mounted on top of bridge frame 202. Power rail 300 is situated above the centre line between each pair of tracks 1 and 106, and may be continuous or may have turntables at points of intersection between sections between pairs of tracks 105 and tracks 106 (not shown).

Bridge beam 200 is provided with moving means consisting of four motor-driven trucks 208 spaced about the annular bridge beam and each having a shaft 209 mounted slidably through a bracket 210 Sattached externally to bridge beam 200. The brackets 210 are mounted on bridge beam 200 at points such that the truck shafts oo 209 are located at the opposite ends of two diameters of bridge 90*0 O beam 200 perpendicular to each other. Shaft 209 may be rotatable 150. in bracket 210, allowing trucks 208 to be rotated. Rotatable trucks are required when moving the electrode handling machine transversely to another row of cells.

0 o As shown in more detail in Figure 4, a motor-driven truck 208 is attached to shaft 209 passing through bracket 210 on bridge beam 0 200. A truck 208 has two wheels 400 that are driven by means of a motor 401, differentials. 402 and drive shafts 403 operatively Sconnected to the wheels. Shaft 209, which is hollow, is vertically movable in and through a sleeve 404 extending through bracket 210 and a screw housing 405 mounted on top of bracket 210. On top of screw housing 405 is mounted a stepping motor 406 adapted to drive a screw 407 concentrically mounted on shaft 209 14 and passing freely through screw housing 405 and threadedly engaging nut 408 fixedly attached to bracket 210. Screw 407, at its other end, is attached to a piston 416 in cylinder 418 mounted inside shaft 209, shown by ghost lines, and has a swivel joint 420. The bridge beam 200 is hydraulically counterbalanced relative to shafts 209 by a hydraulic system that includes said piston and cylinder in communication with an accumulator 220 (Figure By activating motor 406, screws 407 are rotated and bridge beam 200 together with bridge frame 202 is moved either up or down on shafts 209 while hydraulically counterbalanced by accumulator 220. The counterbalance is designed such that it absorbs the load of the bridge beam, the bridge frame and the 0~e grab frame assembly with half the number of anodes from a cell a#oe O suspended therefrom.

O0 eoo( 00 0 iC00o With reference now to Figures 5A-5D, in order to locate the electrode handling machine 104 over a desired cell so that electrodes may be removed from or placed in a cell, it is 0ob. necessary to position the machine accurately and in fixed 0004 position to eliminate any relative movement between machine and cells. A locating bracket schematically shown at 500, is mounted .40.

at at least two of the four corners of each cell and is adapted to receive 4 a positioning cone or wedge, schematically indicated 00 0 o with numeral 501, mounted at at least two of the four lower corners of the bridge frame 202, the remaining corners having flat landing pads (not shown). The machine 104 is moved over a desired cell 101 (Figure 5A) with the grab frame assembly 204 in a position such that cones 501 are positioned substantially *1

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vertically above locating brackets 500. The stepping motors 406 on the brakets 210 of the bridge beam 200 are activated to lower the bridge beam 200 with bridge frame 202 until the cones 501 are securely placed and seated in locating brakets 500 (Figure The stepping motors remain activated causing the trucks 208 to be raised off tracks 105 (Figure 5C). No movement can now occur between the electrodes 700/701 (Figure 7) and grab frame assembly 204 that is supported vertically movable in bridge frame 202.

The grab frame assembly 204 is subsequently lowered to pick up electrodes from the cell (Figure 5D), as will be described.

When the desired electrodes have been engaged and picked up, the grab frame assembly is raised, the stepping motors 406 are re- 0o activated to lower the trucks back on the tracks and, aaoa o subsequently, to raise the bridge beam 200 with bridge frame 202 0 4460 15 to remove cones 501 out of brackets 500. Raising is continued

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0o0 until the picked-up electrodes clear the cells. Motors 406 are stopped and the electrode handling machine is moved to another desired position such as over a wash cell or a drip cell, or to o" a conveyor of a cathode stripping machine or an anode cleaning machine. The procedures for placing electrodes in or removing electrodes from a cell or conveyor are similar.

osr With reference to Figure 6 (see also Figures 2 and the bridge frame 202 comprises the vertically movable grab frame assembly, generally indicated with 204. Grab frame assembly 204 is vertically movable by means of two motors 221 and four gear boxes 222, all interconnected with rotatable shafts 223, and all mounted in a rectangular configuration on top of bridge frame

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202. The motors 221 in cooperation with gear boxes 222 and interconnecting shafts 223 drive four screws 705, more clearly shown in Figure 7, adapted to vertically move electrode grab frame assembly 204. The four motor-driven screws 705 are, preferably, low friction, roller screws. In an alternative embodiment, the screws 705 may be replaced with motor-driven chains and sprockets (not shown) suitably connected to the gear boxes 222 and grab frame assembly 204.

Bridge frame 202 comprises an upper beam structure 601, conveniently of polygonic shape (Figure 2) supporting power room 205, electronics room 206 and air conditioner 207 in two diametrically opposite areas of the frame. Bridge frame wheels 203 are rotatably attached at the circumference of upper beam t structure 601. Bridge frame 202 also comprises a central beam 6 6 h structure 602 which is integrated with but extends below the Q4 Ot* J upper beam structure 601, and is adapted to contain and suspend grab frame assembly 204. Both upper and central beam structures o 601 and 602 respectively are provided with conventional steel 0010 'C 0 cross beams and reinforcing beams as necessary to provide rigidity and strength, as well as to provide rigidity for the movements of the grab frame assembly to avoid misalignment between assembly and electrodes.

The central beam structure 602 is of a generally rectangular construction, its long centre line being perpendicular to the direction of the tracks 105, and with dimensions adequate for positioning on the locating brackets 500 and for accommodating L I I 17 electrodes 700/701. Spaced-apart positioning or locating cones or wedges 501, which can fittingly insert partly into locating brackets 500 on a cell, are attached to the underside of two opposite lowest cross beams 603, located at the lower lengthwise extremities of the central beam structure 602. Either two or four cones or wedges with corresponding brackets on a cell may ~O~f*ofal be used. Two, water spray headers 604 are attached at the lower extremity of the bridge frame by means of a number of brackets 605 parallel to the long centre line of central beam structure 602 and outside thereof. The spray headers 604 have a number of nozzles (not shown) spaced along their lengths and are connected to a source of water (not shown) that, when activated, allows spraying of electrodes that are being removed from a cell.

a Also provided at the lower end of central beam structure 602 are "o Op+ionlll Adrip shields 606, shown by ghost lines, adapted to be moved under or away from under electrodes lifted from a cell into the central beam structure by grab frame assembly 204. Drip shields 606 are preferably flexible sheets or liquid-impervious membranes movable o by cables 620 between guide sheaves 607 placed at intervals along and attached to central beam structure 602. The shields are positioned such that they will not interfere with the placing of bridge frame 202 on a cell. Preferably, two drip shields 606 are Go 0 D installed, each covering half the longitudinal distance between cross beams 603. The drip shields 606 may be moved under or removed from under central beam structure 602 by means of motordriven rolls 608, as shown with interrupted lines, on which the drip shields are collected and which are operatively connected

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~1 18 with the cables. The drip shields are pulled under electrodes from rolls 608, after the electrodes have been lifted from a cell, to collect any dripping electrolyte, and are usually retracted onto rolls 608 just prior to lowering the pulled electrodes into a wash cell.

Suspended in the central beam structure 602 is the vertically movable grab frame assembly 204. Grab frame assembly 204 can be lowered onto electrodes and can be raised to remove the desired set of electrodes from a cell into the bridge frame so that the bottom of the electrodes clear the top of the cells. The operation for placing electrodes in a cell is similar.

The grab frame assembly 204 is raised and lowered by means S described, and is hydraulically counterbalanced by a counterbalance chain 609 attached between each corner of the grab frame assembly at fixed point 610, via a sprocket wheel 611, and a piston in a hydraulic cylinder 612, which is connected to a tic, liquid and gas-filled accumulator 613. Cylinder 612 is dependantly attached at its upper end to a bracket 614 on bridge frame 202. The counterbalancing is designed such that the counterbalance absorbs the load of the grab frame assembly 204 and half the number of anodes from a cell suspended therefrom.

oo SIn Figure 6, sprocket wheels 611 are own in the upper position with the grab frame assembly 204 in L. full upward position.

Wheels 611 are also shown, with interrupted lines, in the full downward position on bracket 614, when the grab frame assembly 204 is in its lowered position on electrodes in a cell. Bracket 1, I -L I I 1 19 614 also supports cylinder 612 and accumulator 613. Thus, the rotation of the screws 705 to lower or raise the grab frame Lssembly 204 compresses or retracts the piston in cylinder 612 causing hydraulic liquid to flow into or out of accumulator 613 thereby compressing or expanding the gas and reducing the load on the screws, thus saving on the power that would be required for moving the full load.

As will be described in more detail with reference to Figures 7, 8 and 9, the grab frame assembly 204 generally comprises cross beam structure 706 with attached slider means 710 and two oO0 parallel, spaced-apart grab support beams 714 each with an anode Slifter beam 800 and a cathode lifter beam 801 for selectively aroo engaging electrodes 700/701.

e Q0 0 0 0 00 o With reference now to Figure 7, the grab frame assembly 204 is adapted to lift electrodes from or place electrodes in a cell.

Tne electrodes comprise generally equispaced, alternating anodes O 700 and cathodes 701, each having an electrode header bar 702 0004 provided with a pair of anode lifting lugs 703 for the anodes and cathode lifting lugs 704 for the cathodes, respectively. The o004 lugs 703 and 704 are in the shape of a hook or a with a horizontal portion by which electrodes may be engaged and lifted 0 Su o from a cell. The horizontal portion of hook-shaped lifting lugs are directed in opposite directions for anodes and cathodes, i.e.

outwardly for anodes and inwardly for cathodes, as shown.

!1 n In more detail, the grab frame assembly has a pair of spacedapart cross beam structures 706, each structure 706 consisting of a pair of parallel spaced-apart cross beams 707 positioned in a direction parallel to the electrodes in a cell and connected together with a pair of spaced-apart plates 708 welded to the bottom of the cross beams of a pair. Each plate 708 between cross beams 707 has an opening therein with attached thereto a nut 709 through which passes a roller screw 705 in threaded engagement. As described, roller screws 705 may be rotated by drive means consisting of motors 221, gear boxes 222 and shafts 223 on top of the bridge frame 202 for raising or lowering the f grab frame assembly 204. In an alternative embodiment (not S shown), the assembly 204 is vertically movable by chains and 4 «Q sprockets, instead of screws and nuts, appropriately attached i6, between the frame and the gear boxes.

o a o Attached to the bottom of each cross beam structure 706 between plates 708 is a pair cf spaced-apart slider means generally indicated with 710. Each slider means 710 consists of two outer, oo, °o°o fixed bearing brackets 711, which are invertedly attached to the underside of the cross beams 707 of a cross beam structure 706, and an intermediate bearing bracket 712, which is reciprocally slidable on a bearing shaft 713 connecting two opposite outer S" bearing brackets 711. Attached to each of the intermediate slidable bearing brackets 712 in one cross beam structure 706, and to each of the lengthwise corresponding intermediate bearing brackets 712 in the other cross beam structure 706 is a grab support beam 714, providing a pair of parallel, spaced-apart grab i i -L i 21 support beams 714 attached to intermediate bearing brackets 712.

Grab support beams 714 are thus slidably suspended from the two cross beams structures 706 of the grab frame assembly and are located substantially vertically above the lifting lugs of the electrodes in a cell. The grab support beams 714 may be connected by intermediate connector beams 715. To the undersides of each of the grab support beams 714 are attached an anode lifter beam 800 and an adjacent cathode lifter beam 801, to be described, so that the anode lifter beams are the inner or outer beams and the adjacent cathode lifter beams are the outer or inner beams, respectively, on the grab frame assembly.

tf 0 The two grab support beams 714 with attached electrode lifter beams 800 and 801 are recprocably movable over a short distance if by means of indexing actuator 716 for indexing the lifter beams f oo 1 5 to one set or to the other set of alternate cathodes or alternate anodes. Indexing actuator 716 is centrally positioned on top of a connector beam 715, and consists of a power-driven ball screw 717 and an electro-mechanical actuator mechanism 718. The screw :0 ~17 is rotatably connected between the actuator mechanism 718 and S20 o a cross beam 707 of one of the cross beam structures 706. When the actuator 716 is activated, the screw 717 will extend or retract relative to cross beam 707 and thereby slide the 0« 0 intermediate connector beam 715 and grab support beams 714 with attached lifter beams 800 and 801 on the shafts 713 supported by brackets 711 and 712 over a short distance sufficient to cause indexing.

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22 With reference to Figure 8, each anode lifter beam 800 and adjacent cathode lifter beam 801 consists of an elongated boxlike member having a number of corner slots 802, partly cut out in the junctures of the outside vertical walls 803 and 804 with the bottoms 805 and 806 respectively (see Figure 11) of the adjacent beams 800 and 801. Slots 802 are adapted to receive a horizontal portion of the anode or the cathode lifting lugs 703 or 704, respectively. Slots 802 are equi-spaced along the length of beams 800 and 801, and the number of slots corresponds to the number of electrodes in an electrolytic cell.

1 On each of the bottoms 805 and 806 of the box-like members of the lifter beams 800 and 801 is positioned an anode shifter comb 807 or cathode shifter comb 808, as applicable. Each shifter comb 807 or 808 consists of an elongated flat plate portion 809 with 14 a reinforcing member 810 attached thereto and a number of lateral flat protrusions 811 horizontally extending from plate portion 809, the number of protrusions 811 corresponding to half the number of anodes or half the number of cathodes in a cell. The *041 protrusions 811 of a lifter comb are spaced from each other at distances that equal the distance between the centre lines of oo alternate anodes or alternate cathodes, the spacing, therefore, being essentially equal to about four time the electrode spacing 00o 0 S in a cell, allowing for the thickness of the electrodes. The protrusions 811 on an anode shifter comb 807 and the protrusions 811 on a cathode shifter comb 808 are offset with respect to each other over a distance equal to the distance between the centre lines of an anode and a cathode, i.e. essentially the distance 23 between two electrodes in a cell, allowing for electrode thickness.

The operation of engaging electrodes in a cell will now be explained with reference to Figures 8, 9, 10A and 10B. When the electrode handling machine is positioned on a cell, the corner slots 802 in the electrode lifter beams 800 and 801 are in a position vertically above the lifting lugs 703 and 704, as shown in Figure 8. When the electrode grab assembly 204 is lowered onto the electrodes, the horizontal portion of the lifting lugs extends into slots 802, as shown in Figure 9 for anode lifting oo lugs 703. By moving a shifter comb from its "neutral" position, 0O00 0o° wherein protrusions 811 do not overlap with any of slots 802, to 60*0 000 an overlapping position, either half of anodes or half of the oooo 600 cathodes can be engaged as the protrusions have now moved under the horizontal portions of the lifting lugs of alternate anodes or alternate cathodes, depending on whether an anode shifter comb or a cathode shifter comb has been moved. By raising the grab o 000 S frame assembly, a set comprising half the number of anodes, i.e.

4o40 0 alternate anodes, or half the number of cathodes in a cell, i.e.

20.: alternate cathodes, will be engaged and lifted from the cell.

0044 By indexing the grab support beams over the distance between two S electrodes, the movement of the shifter combs will allow engagement with the alternate set of alternate anodes or alternate cathodes. When the grab frame is lowered for setting a set of electrodes into a cell, movement of the shifter combs disengages the electrodes once the electrodes are positioned.

The movements of the anode shifter combs 807 and the cathode shifter combs 808 between the neutral, engaging and disengaging positions can be carried out independent of each other. The anode shifter combs 807 are operated in unison, as are the cathode shifter combs 808. The shifter combs are capable of moving between the positions, the movements of each shifter comb being controlled by an actuator 1100 and a number of limit switches 1101 to be described with reference to Figure 11.

In Figure 11, an electro-mechanical actuator 1100 is shown positioned at one end of each lifter beam 800/801 and a number of limit switches 1101 are shown positioned at the opposite end of each lifter beam 800/801. For a pair of adjacent lifter Sbeams, the actuators 1100 are preferably positioned at opposite ends. An actuator 1100 is operatively connected between a lifter beam and a shifter comb. Actuator 1100 is pivotally attached at cross piece 1102 in one end of the box-like member of a lifter beam. The actuator 1100 comprises a rotating rod with ball screw C 1103 and fixed nut (not shown) pivotally attached with end 1104 in bracket 1105 on the reinforcing member 810 on a shifter comb 807/808. Upon the receipt of a signal by the actuator 1100, rod 1103 rotates to extend or retract bracket 1105 connected to a reinforcing member 810 over a predetermined distance controlled Sby the limit switches 1101, and moves the attached shifter com over that predetermined distance.

The limit switches 1101 are operatively connected to the shifter comb, and are mounted on a vertical plate 1106 on a vertical wall I at an end of each box-like member of a lifter beam 800/801. Each switch 1100 has a small wheel 1107 operatively connected thereto and below the switch in rolling engagement with a reciprocable cam rod 1108 operatively mounted with respect to and below wheels 1107 of the said limit switches. Cam rod 1108 is supported towards both ends in brackets 1109 through which cam rod 1108 is slidably reciprocable. One end 1110 of cam rod 1108 is pivotally mounted in a bracket 1111 positioned on top of reinforcing member 810 of a shifter comb 807/808. Cam rod 1108 has four cams 1112 a, b, c and d, which are adapted to cause activation of a limit switch when a wheel passes over a cam. Cams 1112b and c, and corresponding switches 1101, define the limits of travel of a t. shifter comb 807/808 in both directions. Cam 1112a defines .j travel in the right hand direction from the neutral position, wherein protrusions 811 on a comb do not cover slots 802, into a position for engaging or disengaging one set of alternate anodes or cathodes for pickup or release. Cam 1112d defines travel in the left hand direction from the neutral position into .1 a position for engaging or disengaging the other set of alternate "2P* anodes or cathodes for pickup or release.

Sa It is understood that variations and modifications may be made to the embodiments of the invention without departing from the 0 00 scope and purview of the appended claims.

Claims (15)

1. A system for handling electrodes used in the electro- deposition of metals comprising: a plurality of electrolytic cells arranged in at least one row, each cell containing a multiplicity of electrodes consisting of substantially equi-spaced, alternating anodes and cathodes, each electrode having an electrode header bar provided with a pair of lifting lugs, each lug comprising a horizontal portion arranged such that a horizontal portion of the lifting lugs on the S, header bars of anodes is oppositely directed to a oo0 horizontal portion of the lifting lugs on the header bars 00 0 of cathodes; an electrode handling machine adapted for moving on o "o parallel tracks mounted on opposite sidewalls of the electrolytic cells in a row, said machine having a bridge beam and means for' raising and lowering said bridge beam; Saacf tr'ia A/vve v auif 'WieuS a bridge frame mounted on said bridge beam;Xa grab frame ooo °ao assembly suspended in said bridge frame and adapted for vertical movement; twy parallel grab support beams slidably suspended from said grab frame assembly; 0 00 °an anode lifter beam and a cathode lifter beam attached to each of said grab support beams; each of said lifter beams having a number of corner slots Z) 27 corresponding to the number of electrodes in a cell and adapted for receiving the horizontal portion of said lifting lugs therein; and a shifter comb in each of said lifter beams adapted to engage a horizontal portion of the lifting lugs of alternate anodes or alternate cathodes.

2. A system for handling electrodes as claimed in claim i, wherein said at least one row additionally comprises one or more electrode wash cells and one or more drip cells, and said parallel tracks are extended over the feed conveyors and discharge conveyors of machines for the 0 stripping of deposited metal from the cathodes and for aor the cleaning of anodes whereby said electrode handling 0000 machine can pick up electrodes from or release electrodes 00 o: onto said conveyors.

3. A system for handling electrodes as claimed in claim 1, wherein said system comprises at least two rows of 0 electrolytic cells each having a pair of parallel tracks, 0000 0000 00 a the tracks of each pair being mounted on opposite o sidewalls of the electrolytic cells, a pair of parallel transverse tracks transversely directed to said pairs of parallel tracks, said pairs of tracks and said pair of 0 parallel transverse tracks providing points of intersection, and a motor-driven turntable at each point of intersection of said tracks to place said electrode -28- handling machine on a pair of parallel tracks or on said pair of parallel transverse tracks.

4. A system for handling electrodes as claimed in claim 3, wherein said electrode handling machine has four motor- driven rotatable trucks adapted for movement on said tracks and for rotation by said motor-driven turntables. An electrode handling machine used in the electro- deposition of metals in a plurality of substantially rectangular electrolytic cells arranged in a row and having parallel'tracks mounted on opposite walls of said cells, each cell containing a multiplicity of electrodes o°°o consisting of 'substantially equi-spaced, alternating anodes and cathodes, each anode having an anode header 09o0 bar with two spaced-apart anode lifting lugs each having a horizontal portion and each cathode having a cathode header bar with two spaced-apart cathode lifting lugs each having a horizontal portion, a horizontal portion 4* 44 rq," *of said anode lifting lugs being oppositely directed to a horizontal portion of said cathode lifting lugs; said electrode handling machine comprising a -a-nnul vertically movable bridge beam; o means for moving said machine on said tracks; a br.idge frame supported on said bridge beam;A a vertically movable grab frame assembly suspended from said bridge frame; a s f Z i A Lk (i Ji_: -29 two parallel grab support beams slidably suspended from said grab frame assembly; an anode lifter beam and a cathode lifter beam attached to each of said grab support beams; each of said anode lifter beams and each of said cathode lifter beams having a number of equi-spaced corner slots adapted for receiving respectively the horizontal portion of said anode lifting lugs and said cathode lifting lugs; an anode shifter comb in the anode lifter beam for engaging or disengaging a horizontal portion of the anode lifting lugs of alternate anodes; and a cathode shifter comb in the cathode lifter beam for I S engaging or disengaging a horizontal portion of the r rcathode lifting lugs of alternate cathodes. fit(

6. An electrode handling machine as claimed in claim wherein said means for moving said machine on said track comprises four motor-driven trucks spaced about the annular bridge beam and each attached to a shaft slidably r ,rpassing through a bracket externally attached to said annular bridge beam.

7. An electrode handling machine as claimed in claim 6, wherein said bridge beam is vertically movable by motor- driven screws concentrically mounted within said shafts. (0 A^'^A 30 *r D I I6 I 044 1 00*0 o 04 S00 0 *4 040 04 0. 00 44

8. An electrode handling machine as claimed in claim 6, wherein said bridge beam is vertically movable by motor- driven screws concentrically mounted and hydraulically balanced on said shafts.

9. An electrode handling machine as claimed in claim 6, wherein said shafts are rotatably mounted in said brackets for rotating said trucks. An electrode handling machine as claimed in claim wherein said bridge frame is fixedly supported on said bridge beam.

11. An electrode handling machine as claimed in claims S c cAALhIct\r b.cg4e bcOL* .r sc4 stA anulo- 'brije beami, through 9, wherein said bridge beam is provided with a circular bridge beam track thereon, and said bridge frame has four equi-spaced support wheels engaging said track whereby the bridge frame is rotatably supported through 1800 of rotation on said bridge track.

12. An electrode handling machine as claimed in claim wherein said bridge frame has an upper beam structure and a central beam structure integrated with and extending below said upper beam structure, said central beam structure having a generally rectangular construction with a lower extremity adapted to contain and suspend said grab frame assembly. 9 I I 31

13. An electrode handling machine as claimed in claim 12, wherein each cell has at least a pair of spaced apart Sao~ dCt' locetas t o ostAS mCoesa-eec locating brackets andat least two positioning cones are mounted at the lower extremity of said central beam structure for secure placement in said locating brackets on a cell when said bridge beam and supported bridge frame are lowered onto said cell.

14. An electrode handling machine as claimed in claim 12, wherein a water spray header is provided on either side of the lower extremity of said central beam structure parallel to its long centre line and outside thereof. I i 4 (4 An electrode handling machine as claimed in claim 12, wherein drip shields are provided adapted to be moved under or away from under said central beam structure.

16. An electrode handling machine as claimed in claim 1( wherein said drip shields are flexible sheets movable by cables between guide sheaves placed along and attached a to said central beam structure, and are moved under or are removed from under said central beam structure by means of motor-driven rolls operatively connected with said cables for collecting said drip shields.

32- 17. An electrode handling machine as claimed in claim 12, wherein said grab frame assembly is suspended in said central beam strucutre and is adapted for vertically moving a selected set of electrodes into said bridge frame. 18. An electrode handling machine as claimed in claim 12, wherein said vertically movable grab frame assembly is hydraulically counterbalanced. 19. An electrode handling machine as claimed in claim 12, wherein said grab frame assembly comprises a pair of parallel spaced-apart cross beam stuctures in a direction parallel to the electrodes in a cell, said cross beam Atistructures each having two threaded nuts attached to li't openings therein positioned in locations spaced-apart and rt in proximity to the extremities of said cross beam structures. v 20. An electrode handling machine as claimed in claim 19, wherein said grab frame assembly is vertically movable by means of four motor-driven screws rotated by drive means positioned on top of said bridge frame, each screw rotatably passing through a threaded nut attached to said cross beam structures.

33- 21. An electrode handling machine as claimed in claim wherein said grab frame assembly comprises two spaced- apart parallel pairs of spaced-apart cross beams, said grab support beams are slidably suspended from said grab frame assembly by means of two pairs of spaced-apart slider means, each pair of slider means consisting of two outer bearing brackets invertedly attached to the underside of said cross beams and an intermediate bearing bracket slidable on a shaft connecting two opposite outer bearing brackets, said grab support beams are attached to said intermediate bearing brackets in parallel between said two pairs of cross beams, and said grab support beams are operatively connected to said cross beam structures for slidable movement relative thereto. 22. An electrode handling machine as claimed in claim 21, wherein said grab support beams are operatively connected to said cross beam structures by means of an indexing actuator for slidably and reciprocably moving said grab r support beams over a distance adequate for indexing said irri S' ,anode lifter beam and said cathode lifter beam on each grab support beam to one set or to the other set of 6a alternate anodes or alternate cathodes. S23. An electrode handling machine as claimed in any of claims through 22, wherein each said anode lifter beam and said cathode lifter beam consists of an elongated box- i -34- i: like member having an outside vertical wall and a bottom, a number of corner slots equi-spaced along the length of a beam, each slot partly cut out in said vertical wall and said bottom at the junctures thereof, the number of slots corresponding to the number of electrodes in an electrolytic cell. 24. An electrode handling machine as claimed in claim 23, wherein said anode shifter comb and said cathode shifter comb each consists of an elongated flat plate portion and a number of flat protrusions horizontally and laterally extending from said plate portion, the number of protrusions corresponding to half the number of anodes 00. o and half the number of cathodes in a cell, respectively, tj said protrusions are spaced from each other at distances 044* 0 t equal to the distance between the centre lines of alternate anodes or alternate cathodes, respectively, and 0'4 the protrusions on an anode shifter comb and the protrusions on a cathode shifter comb are offset with r r respect to each other over a distance equal to the 40*0 111:4 1distance between the centre lines of an anode and a A 0 6cathode. as An electrode handling machine as claimed in claim 24, 6 wherein said anode shifter comb and said cathode shifter comb are capable of moving independently of each other between positions controlled by an actuator and a number L i of limit switches positioned at opposite ends of a lifter beam. 26. An electrode handling machine as claimed in claim wherein said actuator is operatively connected between a lifter beam and a shifter comb for movement of a shifter comb over a predetermined distance, said limit switches are operatively connected to said shifter comb by means of a cam rod operatively mounted with respect to the limit switches, said cam rod having four cams adapated to cause activation of a limit switch, said cams defining said positions of said shifter comb. o 27. A system for handling electroder used in the electro-deposition 0 of metals substantially as hereinbefore described with reference to the accompanying drawings. Oti D A T E D this 2nd Day of April, 1990 COMINCO ENG+NEER-+N-SERV-e--eES LTD. By its Patent Attorneys CALLINAN LAWRIE o A r i L t-