US2129868A

US2129868A - Article supporting rack for plating

Info

Publication number: US2129868A
Application number: US103872A
Authority: US
Inventors: Pearson Albert
Original assignee: Western Electric Co Inc
Current assignee: AT&T Corp
Priority date: 1936-10-03
Filing date: 1936-10-03
Publication date: 1938-09-13
Anticipated expiration: 1955-09-13

Description

Sept 13, 1938. A. PEARSON ARTICLE SUPPORTING RACK FOR PLATING' Filed Oct. 3, I936 fill filial? A. PARso/v #Q Mm ATTORNEY Patented Sept. 13, 1938 ARTICLE SUPPORTKNG RACK FOR PLATENG Albert Pearson, Western Springs, 111., assignor to Western Electric Company, Incorporated, New York, N. Y, a corporation of New York Application October 3,

"' 3 Claims.

This invention relates to article supporting racks, and more particularly to racks for plating sheet metal.

Certain articles require a localized coating and it is often desirable to restrict the covered areas, particularly when costly coating materials such as gold or other noble metals are employed. In some cases it is desirable to coat one side of a metal sheet and subsequently to form the composite sheet into the article.

. An object of this invention is to provide an improved method and rack for use in the application of a localized coating on sheet material.

In accordance with. one embodiment of the invention, a rack is provided for supporting a metal strip in a plating apparatus and localizing the deposit of metal on one face thereof. The

rack comprises'a continuous surface having an oval section on which the strip is wound spirally and clamped to prevent contact between the electrolyte and the under surface of the strip. Plating current'is conducted to the strip through a contact bar along the top of the rack.

A complete understanding of the invention may be had from the following detailed description taken in conjunction with the appended drawing in which the single figure is a perspective view of a plating rack embodying the invention.

For convenience and economy a plating rack embodying the invention is adapted for use in a conventional electroplating apparatus in which the rack is suspended from a. his bar ID in an electrolyte (not shown).

As shown in the drawing, a supporting frame made of wood, fibre, or other insulating material comprises a main rectangular vertical frame member H which has a rounded bottom portion I2. A plurality of cross members orarms extend horizontally and symmetrically 4 from the two faces of the main member at right angles thereto. A central cross arm I3 is supported at the approximate middle of each face of the main member. Two upper cross arms l4 and two lower cross arms l5 mounted nearthe respective endsof the main member are relatively shorter than the central arms so that the ends of the cross arms and main member describe-an approximate oval.

Mounted along the full length of the top ofthe main frame member isa half round rod or bar l6 of brass, copper, or other conducting material.

1936, Serial No. 103,872

A bracket H is welded to each end of the rod and fastened to the main frame member with screws.

A continuous sheet is of fibre, rubber or other insulating material, equal in width to the length of the conductor rod is mounted around the outer ends of the frame cross arms and secured thereto with countersunk screws it. The two ends of the sheet abut against the portions of the rod projecting beyond the face of the main frame member and are anchored securely with screws (notshown) to the main member. The projecting portions of the half round rod are made equal to the thickness of the sheet to insure a smooth continuous surface at the junctures between these members. At the bottom of the rack, the sheet nests against the rounded portion of the main frame member and the rod and sheet thus collectively provide a continuous, smooth surface for receiving the strip material.

To each end of the half round rod a formed arm 20 of brass, copper or other conducting material is secured by welding, brazing, or other suitable method, such as threading the arm into the rod to provide a good electrical contact for conducting plating current to the rod. The two arms extend upwards and are each provided with a hook'2l for engaging the bus bar of the plating apparatus and a handle 22 for convenient transportation of the rack.

At the upper left corner of the rack just below the conductor rodis a clamp 23 threaded in the main frame member and provided with an enlarged head of rubber or other non-conducting strip is then wound spirally on the surface of the rack and the conductor rod under suflicient tension to insure close contact between the underside of the strip and the rack surface. ing end of the strip is fastened securely with the right hand clamp to hold the strip and rack in proper relationship. Circulation of the electrolyte against the inner surface 'of the strip is prevented by contact with the rack surface and the deposit of metal on that area is accordingly prevented.

Plating current is introduced to the strip through contact with the half round rod, whichis connected to the bus bar through the supporting arms. Introduction of current to the uniformly spaced intervals of' the strip in contact The terminat- I with the rod facilitates the electrodeposition of a uni orm coating on the strip surface.

In the plating operation, vertically arranged anodes (not shown) are positioned on opposite careful consideration is directed to the frame.

members which are preferably constructed to form the strip supporting surface into an approximately oval section so that all portions of the strip will be in close contact with the convex surface of the rack. For relatively thick material it may be necessary to form the rack more nearly cylindrical in shape to insure continuous contact between the strip and rack? surface. However, a rack having an elongated axis is preferred because this construction presents the strip more uniformly to the plating anode which assists in control of coating thickness and also permits a greater number of racks to be placed in a tankof given length.

The surface of the rack can be made of hard rubber or phenol fibre and in some cases may be faced with soft rubber, depending on the size and composition of the strip material. For plating thin brass strip, hard rubber approximately is" thick was usei satisfactorily and the thin strip was retained in sufficiently close contact with the rack surface without difficulty. For thicker strip or material which does not distort easily a soft rubber facing into which the material can be imbedded may be required. Durable, non-conducting materials are employed for the frame, strip supporting sheet and clamps to prevent the deposit of metal on the rack members and to reduce maintenance and repair costs.

A rack of this general description is also suitable for supporting strip material during coating processes other than electroplating, such as paint or varnish spraying, in cases where it is desirable to restrict the coating to one side of the strip.

Other modifications of the specific structure described herein can be made to accommodate various requirements, and it is to be understood that the invention is limited only by the scope of the appended claims.

What is claimed is:

1. A plating rack for metal strip, comprising a frame of non-conducting material, an elongated member made of conducting material mounted on the frame, a sheet of insulating material mounted on the frame with its ends abutting against the conducting member for receiving the metal strip, a clamp mounted on the frame for securing one end of the strip, a second clamp on the frame for engaging the other end of the strip and holding the strip in close contact with the insulating sheet and the conducting member, and means for conducting plating current to the conducting member.

2. A plating rack for metal strip, comprising a frame of non-conducting material having a main vertical member and a plurality of cross members extending therefrom, a bar of conducting material secured to the top of the vertical member, a continuous sheet of insulating material secured to the end of the frame cross members with its ends abutting the conducting bar, and an arm of conducting material extending from the bar for conducting plating current thereto.

3. A rack for plating metal strip, comprising a frame having a central member and a plurality of cross arms projecting therefrom, a bar of conducting materlal having a semi-circular crosssection secured to the top of the central frame member with portions ofthe bar diameter extending beyond both faces of the frame member, a continuous sheet of insulating material secured to the ends of the frame cross arms with its ends abutting the projecting portions of the con-' ductor bar for supporting the strip, a formed arm secured to the bar for conducting plating current thereto, and a plurality of clamps for securing the strip tov the supporting surface of the rack.

ALBERT PEARSON.