Abstract: 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.

Abstract: A workpiece holder for securing workpieces in a dip bath has an open generally rectangular metal frame having opposite sides. An array of at least four metal rods extending between the opposite sides forms a guide track adapted to receive and hold a row of the workpieces in contact with one another. One of the sides is formed in alignment with the track with a fill hole through which the workpieces may pass to move into and out of the track.

Abstract: An apparatus for treating a workpiece with a liquid has a vessel holding a body of the liquid, a mount provided with a holder for carrying the workpiece, and a lifter for shifting the mount with the holder and the workpiece from an upper position above the body of liquid into a lower position with the workpiece immersed in the body of liquid. An inverting mechanism is coupled with the lifter for rotating the mount, holder, and workpiece through about 180° above the body of liquid on movement from the upper position toward the lower position and from the lower position into the upper position.

Abstract: Cup-shaped workpieces are first each secured in a downwardly open position on respective fingers of a workpiece holder, and to holder is inverted such that the workpieces are open upward and the upwardly open workpieces are lowered into a body of anodizing liquid in a treatment bath until the workpieces are wholly immersed. The holder and the workpiece are then moved horizontally immersed in the body of anodizing liquid while passing electricity between the holder and a cathode immersed in the bath below the workpieces such that the liquid anodizes surfaces of the workpieces. Finally, the holder is raised out of the body of liquid with the workpieces open upward, and while the workpieces are still above the body of liquid, the holder and the workpieces are again inverted so that the workpieces are open downward and any treatment liquid in the workpieces drains downward back into the bath.