Patent GB-741495-A (GB)
Title: Improvements in and relating to apparatus for treating stem assemblies for electric lamps and like devices
IPC: H01K3/30
Filed: 1953-04-13
Abstract: 741,495. Electro -- pickling apparatus. BRITISH THOMSON-HOUSTON CO., Ltd. April 13, 1953 [April 15, 1952], No. 10015/53. Class 41. [Also in Group XI] Apparatus for cleaning the ends of leading-in wires forming part of stem assemblies for electric lamps and like devices, comprises a rotary turret 1 with a plurality of segments 3 hinged upon its periphery and arranged to be raised or lowered relative to the plane of the turret, each segment being provided with a group of holders 2 for lamp &c. stems 4 which are carried automatically through three work stations including respectively, a tank 24 for holding an electrolyte such as a solution of potassium nitrate, jets of rinsing liquid, and air jets for expelling any liquid that may have entered the exhaust tube 13 of a stem assembly, means being provided for tilting the segments to bring the ends 10 of the leading-in wires into and out of the tank 24. A part of the leading- in wires is made of magnetic material so that they may be associated with positioning and holding magnets of the kind described in Specification 705,899, [Group XI]. The turret 1 is divided into eight segments 3, each carrying five stem-holders 2 at the periphery to receive stems 4 which are inserted as the holders are indexed past an operator at station A. The stem holders are formed by slots 7 in the upwardly inclined edges 9 of the segments 3, the stems being inserted with their flared edge 8 resting upon the incline and the end portions 10 of the leading-in wires pointing downwardly. With the stem thus arranged the upwardly extending exhaust tube 13 is located within a vertical slot in the front face of a magnet 14 which is mounted between flanges on a bracket 15 secured on the segment 3, the faces of the poles of the magnet being spaced apart by an amount corresponding to the spacing of the magnetic end portions 11 of the leading-in wires, which extend upwardly and are held in contact with the respective faces of the magnet. The turret segments, which are made of non- magnetic material, e.g. organic plastic, are each connected to a central portion 1<SP>1</SP> of the turret by a horizontal hinge 20 whereby they can be moved upwardly and downwardly by a roller 21, Fig. 2, on their underside travelling upon a cam track 23. The turret advances the stems in a clockwise direction from station A to a position above an arcuate tank 24 containing the electrolyte, e.g. a solution of potassium nitrate, and extending substantially around the left-half of the apparatus, and throughout this travel the cam track causes the respective segments to be lowered so that the inner ends 10 of the leading-in wires and end portion of each pinch 25 are below the surface of the electrolyte. During the movement over the tank an arcuate conductor strip 28 on the central part of the turret bears upon a feeder brush 26 whereby low voltage A.C. is conducted over a lead 30 to an L-shaped metal strip 32 which has an arcuate limb connected by pins 17 to the brackets 15 holding the magnets, the magnets thus serving to conduct current to the ends 11 of the leading-in wires. The circuit from the electrolyte is completed by three carbon posts 35-35<SP>11</SP> immersed therein and connected to cables 33. The body of the tank is insulated by a rubber coating. Upon a turret segment reaching the end of the tank 24 the electrical connection between the strip 28 and the end brush 26<SP>11</SP> is broken, and the segment is tilted upwardly into the plane of the central portion 1<SP>1</SP> of the turret, whereupon the electrolyte on the stems drains into a tray 36. The lower ends of the stems and the end wires 10 are next washed by lowering their relative segment to bring them into the path of jets of warm water from pipes 37-39 located above an arcuate basin 40, after which the segment is again raised to bring the upper end of the exhaust tube 13 into a guide channel 42 below a manifold 43 provided with openings through which jets of air are driven into the exhaust tube to remove any water that may have entered. The stems finally drain into an arcuate tray 51 at which they are removed.