Method of anodizing hollow metallic bodies

摘要

A plurality of cup-shaped workpieces are anodized by first securing each of them in a downwardly open position on an electrically conductive and flat workpiece frame that is then inverted such that the workpieces are open upward and lowered into a body of anodizing liquid in a treatment bath until the workpieces are wholly immersed and the frame is in contact with a horizontal rail. Thereafter the frame is moved horizontally while wholly immersed in the anodizing liquid while electricity flows between the rail and a cathode immersed in the bath below the workpieces such the liquid anodizes surfaces of the workpieces. The frame is raised out of the body of liquid with the workpieces open upward, and, while the workpieces are still above the body of liquid, inverting the frame and the workpieces so that the workpieces are open downward and any treatment liquid drains downward into the bath.

主权项

1. A method of anodizing surfaces of metallic hollow workpieces, the method comprising the steps of:
securing a plurality of the hollow workpieces to respective pairs of electrically conductive and elastically deformable fingers carried on bars of an electrically conductive and flat workpiece base frame; conveying the workpiece frame in a horizontal travel direction in steps in a travel direction along a row of upwardly open treatment baths of which at least one holds an anodizing treatment liquid such that the frame passes from an upstream station at an upstream end of the one bath to a downstream station at a downstream end of the one bath, the one bath holding an electrically conductive rail extending between the stations and submerged in the bath of anodizing treatment liquid, an anode of a power supply being connected to the rail at a point submerged in the bath of anodizing treatment liquid; when the frame is in the upstream station, inverting the frame and workpieces by a rotation of 180° and thereby inverting the workpieces on the fingers and thereafter while still in the upstream station lowering the inverted frame with the inverted workpieces into the upstream end of the one bath into engagement with the rail such that the inverted workpieces are immersed in the one bath; supporting the inverted workpieces and the inverted frame on the rail while displacing the inverted and submerged workpieces and the inverted frame from the upstream end to the downstream end and while flowing electricity from the power supply through the rail, the frame, and the workpieces so as to anodize surfaces of the workpieces; when the frame is in the downstream station, raising the inverted workpieces and the inverted frame and again inverting the frame and workpieces through 180° such that when the workpieces are above the one bath the treatment liquid runs down off the workpieces and into the one bath; and thereafter transporting the frame and workpieces downstream out of the downstream station.