Electroplating rack

Abstract

An electroplating rack includes a pair of uprights carrying pairs of transversely extending arms. Exposed, upwardly facing electrode surfaces are defined at spaced locations along each arm. Crossbars having exposed, downwardly facing electrode faces near opposite ends are removably carried on the pairs of arms with the faces engaging the surfaces. Hook-like article supports depend from the crossbars. The crossbars can be supported selectively at any of the electrode surface locations.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to electroplating racks and more particularly to a novel and improved universal rack capable of efficiently supporting many different types of parts in spaced relationship for electroplating.

2. Prior Art

In modern automatic plating systems, a plurality of rack assemblies are used to support articles to be plated. The racks are hung on a bus bar positioned above tanks containing cleaning, plating and washing solutions. A programmed drive system sequentially moves the racks along the bus bar to prescribed stations over the tanks, lowers the bus bar to submerge the articles in the tank-carried solutions, and raises the bus bar to drain the solutions from the articles and racks before the racks are advanced to the next station.

The articles to be plated are used as cathodes of an electrolytic cell. The anode is formed from the metal to be plated. The electrolyte is a metal salt solution which presents ions of the plating metal to the cathode for deposition. As metal ions are depleted from the electrolyte, they are replenished by the anode.

The racks should be capable not only of securely holding a plurality of articles in properly spaced relationship, but should also provide a low impedence current path and make good electrical contact with the supported articles. Only a minimum surface area of the articles should be shielded from the electrolyte. The racks should be capable of holding a maximum number of articles to accommodate high production volumes, and yet should be of sufficiently simple construction so that circulation of the electrolyte is not inhibited.

Ideally the racks are formed from a minimum number of parts so they can be economically manufactured. The racks should occupy a minimum of storage space. The racks should be adjustable to accommodate a wide variety of articles and no tools should be required to effect the adjustment.

Another consideration in the design of electroplating racks is the need to provide a simple method of varying the amount of electrical current supplied to the articles being plated. Articles having larger plating surface areas need a larger current supply than do articles having smaller surface areas. Still another consideration is that the racks must permit the expedient racking and unracking of articles.

A number of proposals have been made in the prior art to provide adjustable electroplating racks. Most of these proposals have failed to satisfy one or more of the above-listed criteria. Adjustable electroplating racks have typically been of relatively complex design presenting a rather substantial number of interchangeable, removable parts which can be lost when not in use. Most known adjustable racks are cumbersome to adjust and are not really well adapted to properly support a wide variety of parts.

A number of plating shops have found present-day adjustable racks so unattractive that much of their plating work is carried out with specialized racks designed for use with only a limited group of articles. This approach presents serious problems in trying to store the racks between periods of use. A large plating shop typically has hundreds of expensive, specialized racks hung from the ceiling and lining the walls. If the racks are not carefully stored, the insulation which covers most of their electrically conductive structure can be damaged.

SUMMARY OF THE INVENTION

The present invention overcomes the foregoing and other drawbacks of the prior art by providing a highly versatile, easily adjustable, novel and improved electroplating rack capable of supporting a wide variety of articles.

A pair of substantially identical rigidly connected uprights have elongated bodies which depend from hooks and carry vertically spaced pairs of arms. A plurality of exposed, upwardly facing electrode surfaces are defined at spaced locations along each arm. A plurality of crossbars are removably carried by the arms. The crossbars have exposed, downwardly facing electrode faces near opposite ends which engage electrode surfaces. Depending hooks carried on the crossbars support articles to be plated. The weight of the articles and the crossbars helps to hold the crossbars in place on the arms and promotes good electrical contact between the contacting surfaces and faces.

A significant advantage of the improved rack is the ease with which it can be restructured to receive different types of parts. A wide variety of rack configurations can be constructed simply by repositioning the crossbars and decreasing or increasing the number of crossbars which are used.

Another advantage is the ease with which the amount of current supplied to the articles being plated can be regulated. Some of the crossbars are provided with larger diameter electrically conductive hooks than are provided on others of the crossbars. The larger diameter hooks are used to suspend articles having large plating surface areas. The smaller diameter hooks are used with articles having smaller plating areas. The diameter of the hooks helps regulate the current supply to the articles. The versatility provided by having crossbars with different hook diameters enables the same supporting rack to be used with parts having substantially different plating surface areas.

Another advantage is the ease with which articles can be racked and unracked. In some instances it is desirable to rack articles while the crossbars are disengaged from the arms. When this is done, the crossbars can be loaded with parts at one location and then positioned on the racks at another location. Unracking can be easily achieved by removing the crossbars and inverting them to drop the plated articles into a receptacle.

Still another advantage is the extreme simplicity of the racks. They include a bare minimum of components and yet provide a maximum of versatility. When the crossbars are removed, the racks can be nested for storage in a minimum of space.

As will be apparent from the foregoing discussion, it is a general object of the present invention to provide a novel and improved electroplating rack.

Other objects and a fuller understanding of the invention may be had by referring to the following description and claims taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an electroplating rack constructed in accordance with the present invention; and,

FIG. 2 is an enlarged side-elevational view of one of the crossbars used on the rack of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, an electroplating rack is shown generally at 10. The rack 10 has an electrically conductive framework including a pair of uprights 12, 13 and upper and lower tie bars 14, 15. A pair of hooks 16, 18, are provided to support this framework from the bus bar of an automatic plating apparatus.

The uprights 12, 13 have elongated depending bodies 20, 22 which extend in parallel vertical relationship. A plurality vertically spaced pairs of arms 24, 26, 28, 30, 32, 34 formed from electrically conductive metal are carried by the bodies 20, 22. The arms 24-34 each have a pair of distal end regions extending in opposite directions from the plane of the uprights 12, 14. Each distal end region of each of the arms 24-34 is provided with two spaced notches 44. An electrically insulative plastic coating 48 covers the described framework, excluding the hooks 16, 18, and including the arms 24-34 and the bodies 20, 22 except in the regions of the notches 44 where exposed upwardly facing electrode surfaces 46 are defined.

A plurality of crossbars 50 are carried by the arms 24-34. All the crossbars 50 are of identical configuration. Referring to FIG. 2, the crossbars 50 each include a central stem 52 formed from electrically conductive metal. A pair of notches 54 is formed near opposite ends of the stem 52. A plurality of depending, electrically conductive hooks 56 are carried at spaced locations along the stem 52. An electrically insulative plastic coating 58 covers the stem except in the regions of the notches 54 where exposed, downwardly facing electrode faces 60 are defined.

The crossbars 50 are positioned on the arms 24-34 with the faces 60 in electrically conductive engagement with the surfaces 46. When articles are hung on the hooks 56, the weight of the articles together with the weight of the crossbars 50 helps hold the crossbars in place and helps to maintain good electrical contact between the surfaces 46 and the faces 60.

The crossbars 50 can be rearranged on the arms 24-34 as desired to most efficiently support articles for a plating operation. In racking and unracking the articles, the crossbars can be removed from the arms.

The hooks 56 formed from electrically conductive wire. The hooks 56 on any one of the crossbars 50 are preferably of the same diameter, but these diameters may differ from crossbar to crossbar. A crossbar 50 having hooks 56 of relatively large diameter is used to supply the increased current required by large parts having large plating surface areas. A crossbar 50 having hooks 56 of smaller diameter is used with smaller parts which require less current.

Although the invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

Claims

What is claimed is:

1. An electroplating rack comprising:

a. an electrically conductive framework including a pair of rack supporting hooks and a pair of rigidly connected uprights defining an elongated depending body;

b. each of said uprights centrally supporting a plurality of vertically spaced pairs of electrically conductive arms, each of said arms having end regions extending in opposite directions from its associated upright, the arms on one of said uprights being substantially horizontally paired with the arms on the other of said uprights such that each of the arm end regions carried on said one upright has a corresponding arm end region on said other upright;

c. a plurality of spaced, upwardly facing electrode surfaces defined on each of said end regions, the electrode surfaces on the arm end regions of said one upright having corresponding electrode surfaces on said corresponding arm end regions on said other upright, whereby a certain number of pairs of corresponding electrode surfaces are defined;

d. a plurality of electrically conductive elongated crossbars removably carried by said end regions;

e. each of said crossbars having a pair of downwardly facing electrode faces located near opposite ends of said crossbars and extending into electrically conductive engagement with a pair of said corresponding electrode surfaces, said crossbars being supported on said arms by virtue of said faces engaging said surfaces;

f. said crossbars each including a plurality of article support formations disposed at spaced intervals therealong; and,

g. an electrically insulative coating covering said bodies, said arms and said crossbars except within the regions of said surfaces, said faces, and said formations.

2. The rack of claim 1 wherein said end regions are notched at spaced locations along their lengths to define said electrode surfaces, and said crossbars rest in said notches with said faces in engagement with said surfaces.

3. The rack of claim 2 wherein said article support formations depend from said crossbars and define hook-shaped end regions.

4. The rack of claim 1 wherein said article support formations are hook-shaped wires formed from electrically conductive metal.

5. The rack of claim 4 wherein the hook-shaped wires on any of one of said crossbars have common diameters.

6. The rack of claim 5 wherein the hook-shaped wires on one of said crossbars have common diameters different from the common diameters of the hook-shaped wires on another of said crossbars.

7. The rack of claim 1 wherein the number of said crossbars is less than said certain number, whereby some of said corresponding electrode surfaces are not engaged by said crossarms and remain exposed.

8. An electroplating rack comprising:

a. an electrically conductive framework including a pair of spaced, rigidly interconnected uprights each carrying a plurality of arms defining pairs of arm portions which extend transversely of the plane of said framework, each of said arm portions on one of said uprights being substantially horizontally paired with a corresponding arm portion on each other of said uprights, each of said arm portions having a plurality of upwardly facing electrode surfaces defined at spaced locations therealong, each of said electrode surfaces on one of said arm portions being paired with a corresponding electrode surface on its corresponding arm portion, whereby a certain number of pairs of corresponding electrode surfaces are defined;

b. a plurality of electrically conductive crossbars removably carried by said end regions, each of said crossbars including a plurality of depending hooks disposed at spaced intervals therealong for receiving and supporting articles to be plated, said crossbars each having a pair of downwardly facing electrode faces resting on and in electrically conductive engagement with a pair of said corresponding electrode surfaces to support said crossbars on said arm portions; and,

c. an electrically insulative coating covering said uprights, said arms, and said crossbars except within the regions of said surfaces, said faces, and said hooks.

9. The rack of claim 8 wherein said arm portions and said crossbars are notched in the regions of said surfaces and said spaces to provide mating connections therebetween.

10. The rack of claim 8 wherein the number of said crossbars is less than said certain number, whereby some of said corresponding electrode surfaces are not engaged by said crossarms and remain exposed.