IE990063A1

IE990063A1 - Electroplating

Info

Publication number: IE990063A1
Application number: IE990063A
Authority: IE
Inventors: Paul Walsh
Original assignee: Paul Walsh
Priority date: 1998-02-06
Filing date: 1999-02-01
Publication date: 1999-08-11
Also published as: IES80935B2; GB2334037B; IES990064A2; GB2334037A; GB9902368D0

Abstract

An electroplating jig comprises a support frame 5 with cathode racks 20, comprising uprights 26, 202, 203 and transverse support bars 27, 106, 201. To accommodate a wide range of articles 2 to be electroplated the cathode racks 20 have adjustable mounting means and associated locking means. In one case the mounting means comprises sleeves 28, 220 carried by a transverse support bar 27, 106, 201 which are locked in a desired position by locking screws 32, 221. To accommodate a wide range of articles 2 mounting hooks 105, 204, 230 are easily mounted and de-mounted from a transverse support bar 27, 106, 201. The transverse support bar 201 may be coated with an insulating material 206 except in a hook-engaging region 209, 251 of the bar 201.

Description

“ELECTROPLATING” Introduction The invention relates to electroplating and in particular to an electroplating jig, an electroplating system, and method of electroplating a plurality of articles.

There are many steps involved in electroplating. A number of these steps are rate limiting as regards the speed of production. Various attempts have been made to improve the rate of production while maintaining quality. One such known improvement involves the use of a jig for mounting an article or articles to be electroplated.

There are, however, various problems involved in the use of such jigs as they are generally limited to use with specific articles.

There are also problems in that, over time they become damaged and/or consumed in the electroplating process. Furthermore, the electroplating process is, in general, difficult to operate in such a way as to optimise the rate of production of electroplated articles while maintaining product quality.

This invention is therefore directed towards providing a solution to at least some of these problems.

Statements of Invention According to the invention there is provided a rack comprising a pair of main supports, a number of transverse support rods extending between the main supports, and a plurality of hook means which are releasably mounted on the transverse support, at least some of the transverse support rods being movable to accommodate a range of articles and having rod mounting means for engaging OPEN TO PUBLIC INSPECTION WIDER SECTION 28 AND RULE 23 INT CL with the main supports and releasable locking means for locking the movable transverse support rod to the adjacent main support.

In a preferred embodiment the transverse support is substantially insulated except at a hook engaging part thereof. Preferably the hook-engaging part comprises an opening in the insulation to receive a support rod engaging part of a hook for electrical contact therewith.

In one embodiment of the invention the opening is defined by a plurality of axially spaced-apart slots in the insulation of the support rod.

In another embodiment the opening is defined by a substantially continuous noninsulated section of the support rod.

In a preferred embodiment of the invention the hook engaging part of the transverse support rod comprises a projecting hook engaging part which is not insulated at the tip thereof to receive a support rod engaging part of a hook for electrical contact therewith.

Preferably the hook engaging part of the transverse support rod is located adjacent a lower end, in use, of the support.

In a particularly preferred embodiment of the invention the rod mounting means comprises a sleeve at both ends of the transverse support for engaging with the main supports. Ideally, the sleeves are slidably engagable with the main supports for movement relative thereto.

In a preferred arrangement the releasable locking means engages the sleeve to lock the transverse support rod in desired position. Preferably the releasable locking means is a locking screw. In this case, for ease of use preferably the locking means screw threadingly engages the sleeve. Ideally, the locking screw is provided with a handle.

In an alternative arrangement the rod mounting means comprises a number of elements which are interengaged to lock onto a main support.

The interengagable elements may comprise a pair of half sleeves, one of which is carried by the transverse support rod, the sleeve elements being wrapped around a main support.

In a particularly preferred embodiment of the invention the mounting means and the locking means are integral. Typically, the locking means comprises a locking bolt having an upright engaging head portion, the head portion being drawn into engagement by a nut which is fastened to the locking bolt.

The invention also provides an electroplating jig for use in electroplating a plurality of articles in an electroplating bath including a cathodic rack according to the invention.

Preferably the jig comprises a support frame having a cathodic support means including the cathodic support rack and an anodic support means, the anodic support means comprising means for supporting secondary anode means.

Ideally the anodic support means includes a secondary anode bar which extends below the level of the electroplating solution in the electroplating bath.

In one embodiment of the invention the cathodic support means comprises a plurality of spaced-apart cathodic mounting brackets for supporting cathode rods, the secondary anode bar being supported on the cathodic mounting brackets by brackets of insulating material.

Preferably the anodic support means includes in anodic stub at least at one end of the frame which is electrically connected to the secondary anode bar. Ideally, an anodic stub is provided at opposite ends of the frame. Preferably the or each anodic stub supports the secondary anode bar.

The invention further provides an electroplating system having a plurality of separate stations for performing operations associated with electroplating and a hoist for moving an electroplating jig of the invention from one station to another.

In a preferred embodiment of the invention the electroplating system includes an electroplating tank having an anodic contact and a cathodic contact at least at one end of the tank for electrically contacting the secondary anode of the jig and the cathode of the jig respectively. Ideally the electroplating tank has an anodic contact and a cathodic contact at opposite ends of the tank, each for electrically contacting the secondary anode and the cathode of the jig.

Preferably the electroplating tank includes primary anode means on opposite sides of the tank, the primary anode means comprising a primary anode bar and a basket for containing anodic material, the basket being releasably hung from the primary anode bar below the level of the electroplating solution in the tank. In this case preferably the primary anode means includes a hoist connection means for removal of the basket from the electroplating tank to replenish the anodic material.

In one embodiment of this aspect of the invention the includes at least two electroplating tanks and an interconnector for interconnecting the electroplating solution in the tanks to achieve a substantially uniform electroplating solution in the tanks. Preferably, the interconnector comprises a pipe means between the tanks, the pipe means being fitted with a valve means to control the flow of electroplating solution between the tanks. In a preferred arrangement the inlets from the electroplating tanks to the pipe means are located at a position between a quarter and a half of the height of the electroplating solution in the tank, ideally at a position approximately one third of the height of the electroplating solution in the tank.

In another embodiment of the invention the system includes an electroplating solution conditioning system including heat exchanger means for heating and/or cooling the solution to achieve a target temperature of from 20 to 24°C in the electroplating tank.

Preferably the conditioning system includes an electroplating solution temperature sensor, heating means for heating the electroplating solution, and control means for activating the heating means to heat the electroplating solution if the temperature falls below a target temperature.

In a preferred anangement the cooling means comprises a heat exchanger through which the electroplating solution is passed, the heat exchanger having a cooling fluid inlet and a valve means responsive to a control means for closing off the cooling fluid supply if the temperature of the electroplating solution falls below a target temperature.

In another aspect the invention also provides a method for electroplating a plurality of articles using a rack of the invention, an electroplating jig of the invention, or an electroplating system of the invention.

Brief Description of the Drawings The invention will be more clearly understood from the following description thereof given by way of example only with reference to the accompanying drawings in which:IE 990063 Fig. 1 is a perspective view of an electroplating jig according to the invention with articles for electroplating in position; ' Fig. 2 is a side view of the jig with the articles removed; Fig. 3 is an end view of the jig ofFig. 1; Fig. 4 is a perspective view of a detail of the jig; Fig. 5 is a side view of the jig hoisted from a trolley; Fig. 6 and 7 are perspective, partially cross sectional views of cathodic and anodic support details of the jig; Fig. 8 is a perspective view of a trolley used with the jig; Fig. 9 is a perspective view of one arrangement for mounting a transverse support to an upright; Fig. 10 is a cross sectional view of a hook mounting detail of the arrangement ofFig. 9; Fig. 11 is a perspective view of another arrangement similar to Fig. 9; Fig. 12 is a perspective view of another transverse support in position on uprights; Fig. 13 is an elevational view of a hook for use with the support ofFig. 12; Fig. 14 is a cross sectional view of the support and hook; Fig. 15 is a perspective view of another transverse support mounting system; Fig. 16 and 17 are perspective views of an alternative transverse support mounting system; Fig. 18 is a perspective view of the jig in position in an electroplating tank; Fig. 19 is a view of a detail of the electroplating tank; Fig. 20 is a cross sectional view of the electroplating tank; and Fig. 21 is a plan view of part of an electroplating system also according to the invention.

Fig. 22 is a perspective view of portion of another rack according to the invention; Fig. 23 is a cross sectional view of a transverse support rod of the rack of Fig. 22; Fig. 24 is a cross sectional view of the transverse support rod of Figs 22 and 23 with a hook in position; Fig. 25 is a cross sectional view of another transverse support rod with a hook in position; and Fig. 26 is an elevational view of the hook of Fig. 25.

Detailed Description Referring to the drawings there is illustrated an electroplating jig for electroplating a plurality of articles 2 in an electroplating bath 1. The jig comprises a support frame 5 which is lifted by a hoist (not shown) from a trolley 6 into the bath 1.

The support frame 5 has a cathodic support means and an anodic support means. The cathodic support means comprises a pair of longitudinally extending cathode support bars 10 with a number of drop arms 11, to each of which is mounted a cathodic mounting bracket 12. Thus there are, in this case, four spaced-apart cathodic mounting brackets 12, each having a plurality of mounting holes 13 to receive longitudinally extending cathodic support rods 15, on each of which is hung a cathodic rack 20 by means of support hooks 19.

Each of the cathode racks 20 according to the invention supports a plurality of articles to be electroplated. A rack 20 comprises a pair of spaced-apart main supports provided by upright rack bars 26 with a number, in this case three, transverse rack bars 27 extending therebetween.

To accommodate a range of different articles to be electroplated the cathode racks have adjustable mounting means. In this case the transverse support rack bars 27 are movable relative to the upright rack bars 26 to accommodate different articles to be electroplated. In the arrangement of Figs. 9 and 10 the transverse support rack bars 27 have sleeves 28 at both ends for slidably engaging the uprights 26 to adjust the position of the transverse support bars 27. Releasable locking means are provided for locking the sleeves 28 in a desired position relative to the uprights 26. The locking means is in this case provided by a locking screw 32. In this way the cathode racks are readily adjustable to accommodate a wide range of articles. Thus, the same rack can be used to accommodate a range of articles, set-up time is thereby minimised and the rate of production is optimised, particularly when a range of articles are to be plated.

The articles 2 are support on the transverse rods 27 by hooks 100. In the case illustrated in Figs. 9 and 10 the support bar 27 is coated with an insulation material except at contact points 101 with the hooks 100. The hooks 100 are also coated except at the contact points 101 and article engaging tips 102. In this way electrical contact is maintained without sacrificing the insulation of the supports 27 and hooks 100.

Referring to Fig. 11 in this case the locking means includes a locking sleeve 103 which is slidable along the upright 26 and is locked in a desired position to support the sleeve 28 of the transverse bar 27 by a locking screw 104.

Referring to Figs. 12 to 17 various arrangements are illustrated of transverse support bars, mounting means, and hooks. In all of these versions an extra dimension is provided by virtue of the fact that support hooks 105 are readily mounted to and de-mounted from a transverse support 106. The hooks 105 are movable from the release position illustrated in Fig 13 to the support-engaging position of Fig. 14. The support bar 106 has a projecting section 107 with an exposed tip for electrical contact with the hook 105 in the engaged position illustrated in Fig. 14. The remainder of the support bar 106 is covered with an insulating material 109 as illustrated in Fig. 14. In this way, any number of support hooks 105 may be mounted on a support bar 106 to accommodate a wide range of articles to be electroplated.

Referring to Figs 22 to 24 there is an illustrated part 200 of another rack according to the invention. The rack 200 is similar to those described above and includes a transverse support rod 201 extending between main supports 202, 203 and a plurality of hooks 204 which are releasably mounted to the transverse support rod 201. The transverse support rod 201 comprises an electrically IO conducting inner bar 205 which is substantially coated with an electrically insulation material 206 except at a hook-engaging part. The hook engaging part comprises an opening in the insulation which in this case is defined by a plurality of axially spaced-apart slots 209 in the insulation 205 which facilitates electrical contact between a contact section 210 of the hook 204. In this case the slots 209 are formed by cutting away the insulation. This arrangement of hooks 204 and contact slots 209 is particularly advantageous as the slots are easily formed and facilitate ease of mounting and de-mounting of hooks 204, as required. The hooks 204 are easily removed if damaged or if they become worn in use or to accommodate larger articles. The configuration of the hooks 204 is also particularly advantageous for ease of mounting and de-mounting while ensuring that a spring bias force is applied to the hook section 210 to maintain electrical contact. Because only a small area of insulation 206 is removed the support bar 201 has a long life in use as there is a minimum area through which erosive chemicals from the plating process may ingress.

Rod mounting means for mounting the transverse support 201 to the main support uprights 202, 203 in this case comprises a sleeve 220 at both ends of the transverse support 201 which slidably engage with the main supports 202, 203 as described above. Releasable locking means to engage the sleeves 220 and to lock them in a desired position is provided by locking screws 221 which screw threadingly engage through the sleeve 220 to bite into and lock to the main support 202, 203. Each locking screw 221 is operated by a handle 222 for ease of use. It will be noted that the outer surface of the sleeve 220 and handles 222 are covered with an electrical insulating material to prolong the operating life of the rack.

Referring to Figs 25 and 26 there is illustrated part of another rack, also according to the invention. This rack is similar to the rack of Figs 22 to 24 and like parts are identified by the same reference numerals. In this case the opening in the II insulation 206 to receive a support rod engaging part 231 of a hook 230 is defined by a substantially continuous non-insulated section of the support rod. The transverse support rod 205 includes a projecting hook-engaging part 250 which is not insulated at the tip 251 thereof to engage the support rod engaging part 231 of the hook 230 for electrical contact. This is a particularly advantageous arrangement as the non-insulated tip 231 is readily provided. It is advantageous that the projecting part 250 be at a lower end, in use, of the support rod 205. This provides maximum spring effect in the hook 230 which ensures that electrical contact is maintained in situ while the hooks 230 are also readily mounted and demounted.

Referring particularly to Fig. 15 in this case the mounting and locking means are integral and comprise a bolt 110 with an intumed section 111 to engage an upright 26. The bolt 110 is retained in an upright - engaging position by a lock nut 112 which draws the bolt 110 into engagement with the upright 26.

Referring to Figs. 16 and 17 in this case the mounting sleeve is in two half sections 115, 116 which are drawn together in an upright engaging position by a locking screw 117.

Referring particularly to Figs. 6 and 7, the anodic support means comprises an anodic stub 40 which is mounted at one end of the support frame adjacent to the cathode bars 10. The anodic stub 40 is mounted between a pair of oppositely directed channel supports 41, 42 which are attached to the adjacent cathode bar 10. Blocks 45 of electrically insulating material are housed within the support channels 41, 42 to ensure that the anodic stub 40 is electrically insulated from the cathode bars 10. A cranked anodic drop arm 47 is connected to the anode stub 40 and a longitudinally extending anodic support bar 48 extends from the lowermost edge of the drop arm 47 to support a number of secondary anode plates which are hung by secondary anode hooks 49 from the anodic support bar 48.

Thus, the secondary anode bar 48 extends in use below the level of the electroplating solution in an electroplating bath. The anodic support bar 48 is further supported at the low level position by brackets 49 of insulating material attached at one end to a cathodic support bracket 12. In this way the secondary anode plates are efficiently and effectively supported between the cathodic racks to optimise the electroplating process.

Referring to Figs. 18 and 20 one electroplating bath 1 is illustrated with a jig according to the invention in position in Fig. 20. The tank has an anodic contact for electrically contacting the secondary anode stub 40 and a cathodic contact for electrically contacting the cathode support bars 10 of the jig. Such electrical contacts may be provided at one or both ends of the tank 2.

Primary anode means are provided at opposite sides of the tank 2. Each primary anode means comprises a primary anode bar 70 and a basket 71 for containing anodic material. The basket 71 is releasably hung by means of hooks 72 from the anode bar 70 so that the basket 71 is below the level of electroplating solution in the tank.

The primary anode means includes a hoist connection for ease of removal of the basket from the electroplating tank to replenish the anodic material.

Referring now to Fig. 21 in the electroplating system according to the invention there are two electroplating tanks 80, 81 and an interconnector in the form of a pipe 85 fitted with a valve 86 to control the flow of electroplating solution between the tanks to achieve a substantially uniform electroplating solution in each tank. The inlets from the electroplating tanks 80, 81 to the pipe 85 are located at a position between a quarter and a half, most preferably approximately one third of the height of the electroplating solution in the tank. It has been found that this position is optimum to maintain uniformity of the electroplating solution in the tanks 80, 81.

The electroplating system of the invention also includes an electroplating solution conditioning system including a heat exchanger 90 for heating and/or cooling the solution to achieve a target temperature of from 20 to 24°C in the electroplating tank. The conditioning system includes an electroplating solution temperature sensor 92, heating means in the form of a heating element 93 for heating the electroplating solution in the tank, and control means 94 for activating the heating means if the temperature falls below a target temperature.

Cooling means for cooling the electroplating solution is in this case provided by the heat exchanger 90 which has a cooling fluid inlet with a solenoid valve 95 which is responsive to the control means 94 for closing off the cooling liquid supply if the temperature of the electroplating solution falls below a target temperature.

Electroplating solution from the tanks 80, 81 overflows over weirs 97 through delivery pipes 98 to an intermediate tank 99. From the tank 99 the solution is pumped by a pump 100 through a filter 101 to the heat exchanger 90.

The invention provides a rack and an electroplating jig which is highly efficient in use because a plurality of different articles are quickly and easily accommodated. The particular arrangement of the anode connection and the dropping of the secondary anode support bar in use, below the level of electroplating solution in the electroplating tank ensures that the electroplating process is optimised and that the secondary anodes have a prolonged useful life. Further, the dropping of the anode baskets and their case of replenishment also aids optimisation of the electroplating process.

The provision of two interlinked electroplating tanks greatly increases production efficiency without sacrificing the quality of the electroplating. The electroplating conditioning system also greatly enhances production efficiency and product quality.

The invention is not limited to the embodiments hereinbefore described which may be varied in construction and detail.

Claims

1. A rack comprising a pair of main supports, a number of transverse support 5 rods extending between the main supports, and a plurality of hook means which are releasably mounted on the transverse support, at least some of the transverse support rods being movable to accommodate a range of articles and having rod mounting means for engaging with the main supports and releasable locking means for locking the movable transverse io support rod to the adjacent main support.

2. A rack as claimed in claim 1 wherein the transverse support is substantially insulated except at a hook engaging part thereof. 15

3. A rack as claimed in claim 2 wherein the hook-engaging part comprises an opening in the insulation to receive a support rod engaging part of a hook for electrical contact therewith.

4. A rack as claimed in claim 3 wherein the opening is defined by a plurality 20 of axially spaced-apart slots in the insulation of the support rod.

5. A rack as claimed in claim 3 wherein the opening is defined by a substantially continuous non-insulated section of the support rod. 25

6. A rack as claimed in any of claims 2 to 5 wherein the hook engaging part of the transverse support rod comprises a projecting hook engaging part which is not insulated at the tip thereof to receive a support rod engaging part of a hook for electrical contact therewith.

7. A rack as claimed in claim 6 wherein the hook engaging part of the transverse support' rod is located adjacent a lower end, in use, of the support.

8. A rack as claimed in any preceding claim wherein the rod mounting means comprises a sleeve at both ends of the transverse support for engaging with the main supports.

9. A rack as claimed in claim 8 wherein the sleeves are slidably engagable with the main supports for movement relative thereto.

10. A rack as claimed in claim 8 or 9 wherein the releasable locking means engages the sleeve to lock the transverse support rod in a desired position.

11. A rack as claimed in claim 10 wherein the releasable locking means is a locking screw.

12. A rack as claimed in claim 11 wherein the locking means screw threadingly engages the sleeve.

13. A rack as claimed in claim 11 or 12 wherein the locking screw is provided with a handle.

14. A rack as claimed in any of claims 1 to 13 wherein the rod mounting means comprises a number of elements which are interengaged to lock onto a main support.

15. A rack as claimed in claim 14 wherein the interengagable elements comprise a pair of half sleeves, one of which is carried by the transverse support rod, the sleeve elements being wrapped around the main supports.

16. A rack as claimed in any of claims 1 to 15 wherein the mounting means and the locking means are integral.

17. A rack as claimed in claim 16 wherein the locking means comprises a locking bolt having an main support engaging head portion, the head portion being drawn into engagement by a nut which is fastened to the locking bolt.

18. A rack substantially as hereinbefore described with reference to the accompanying drawings.

19. An electroplating jig for use in electroplating a plurality of articles in an electroplating bath including a cathodic rack as claimed in any preceding claim.

20. A jig as claimed in claim 19 comprising a support frame having a cathodic support means including the cathodic support rack and an anodic support means, the anodic support means comprising means for supporting secondary anode means.

21. A jig as claimed in claim 20 wherein the anodic support means includes a secondary anode bar which extends below the level of the electroplating solution in the electroplating bath.

22. A jig as claimed in claim 21 wherein the cathodic support means comprises a plurality of spaced-apart cathodic mounting brackets for supporting cathode rods, the secondary anode bar being supported on the cathodic mounting brackets by brackets of insulating material.

23. A jig as claimed in claim 21 or 22 wherein the anodic support means includes an anodic stub at least at one end of the frame which is electrically connected to the secondary anode bar.

24. A jig as claimed in claim 23 wherein an anodic stub is provided at opposite ends of the frame.

25. A jig as claimed in claim 23 or 24 wherein the or each anodic stub supports the secondary anode bar.

26. An electroplating jig substantially as hereinbefore described with reference to the accompanying drawings.

27. An electroplating system having a plurality of separate stations for performing operations associated with electroplating and a hoist for moving an electroplating jig as claimed in any of claims 19 to 26 from one station to another.

28. An electroplating system as claimed in claim 27 including an electroplating tank having an anodic contact and a cathodic contact at least at one end of the tank for electrically contacting the secondary anode of the jig and the cathode of the jig respectively.

29. An electroplating system as claimed in claim 28 wherein the electroplating tank has an anodic contact and a cathodic contact at opposite ends of the tank, each for electrically contacting the secondary anode and the cathode of the jig.

30. An electroplating system as claimed in claim 28 or 29 wherein the electroplating tank includes primary anode means on opposite sides of the tank, the primary anode means comprising a primary anode bar and a basket for containing anodic material, the basket being releasably hung from the primary anode bar below the level of the electroplating solution in the tank.

31. An electroplating system as claimed in claim 30 wherein the primary anode means includes a hoist connection means for removal of the basket from the electroplating tank to replenish the anodic material.

32. An electroplating system as claimed in any of claims 27 to 31 including at least two electroplating tanks and an interconnector for interconnecting the electroplating solution in the tanks to achieve a substantially uniform electroplating solution in the tanks.

33. An electroplating system as claimed in claim 32 wherein the interconnector comprises a pipe means between the tanks, the pipe means being fitted with a valve means to control the flow of electroplating solution between the tanks.

34. An electroplating system as claimed in claim 33 wherein the inlets from the electroplating tanks to the pipe means are located at a position between a quarter and a half of the height of the electroplating solution in the tank.

35. An electroplating system as claimed in claim 33 or 34 wherein the inlets from the electroplating tanks to the pipe means are located at a position approximately one third of the height of the electroplating solution in the tank.

36. An electroplating system as claimed in any of claims 27 to 35 wherein the system includes an electroplating solution conditioning system including heat exchanger means for heating and/or cooling the solution to achieve a target temperature of from 20 to 24°C in the electroplating tank.

37. An electroplating system as claimed in claim 36 wherein the conditioning system includes an electroplating solution temperature sensor, heating means for heating the electroplating solution, and control means for activating the heating means to heat the electroplating solution if the temperature falls below a target temperature.

38. An electroplating system as claimed in claim 36 or 37 wherein the cooling means comprises a heat exchanger through which the electroplating solution is passed, the heat exchanger having a cooling fluid inlet and a valve means responsive to a control means for closing off the cooling fluid supply if the temperature of the electroplating solution falls below a target temperature.

39. An electroplating system substantially as hereinbefore described with reference to the accompanying drawings.

40. A method for electroplating a plurality of articles using a rack as claimed in any of claims 1 to 18, an electroplating jig as claimed in any of claims 22 to 26, or an electroplating system as claimed in any of claims 27 to 39.

41. Electroplated articles whenever electroplated using a rack as claimed in any of claims 1 to 18, an electroplating jig as claimed in any of claims 19 to 26, an electroplating system as claimed in any of claims 27 to 39, or by a method of claim 40.