GB1376813A - Tumbling barrels for bulk parts - Google Patents

Abstract

1376813 Tumbling barrel H HENIG 13 Jan 1972 [13 Jan 1971] 1579/72 Headings C7B and C7F [Also in Division B6] A tumbling barrel (e.g. for use in etching, electroless plating and then electro-plating of plastics articles or for anodically polishing metal articles) comprises a pair of end-walls 11 both having a plurality of apertures formed therein and being rotatably mounted about a common axis, a perforate peripheral casing 13 having at least one closeable opening 14, an inner cylinder 18 and an electrical contact element 19 for supplying current to a contained batch 1 of parts, the length of the barrel being less than its diameter. For the illustrated barrel, the peripheral casing 13, end-walls 11 and lids 15 are of electrically non-conductive material. The end-walls 11 have large cylindrical holes therein in which are fastened perforated discshaped inserts 12. The barrel is supported by a carrying arm 22 and by tubular and disc-shaped elements 24 and 25 fastened to supporting legs 20 of the electrical contact 19. The barrel is supported within an electrolyte bath 7 and is surrounded by electrodes 5 and 6 of opposite polarity to the contact 19. In alternatives and modifications, the peripheral casing may be of circular cross-section or may be prismatic. The inner cylinder 18 may be hollow or solid and of circular or polygonal cross-section and may taper slightly along its length. It may be of electrically non-conductive or of conductive material and serve as the electrical contact for articles being treated. The electrical contact 19 can be mounted so that it rotates with the barrel or stationarily so that it does not. A soluble or insoluble anode may be mounted within the cylinder 18 when this is perforated and of electrically insulating material. Three barrels may be mounted on a common axis Fig. 5 (not shown). In use, barrels may be rotated at less than 8 revolutions per minute. Acrylonitrile-butadiene-styrene buttons may be electro-plated with Ni. Screws or electronic constructional elements may be treated in the barrels.