Patent GB-190414733-A (GB)
Title: Improvements in Electric Arc Lamps.
Inventor: CAROLAN EDGAR ALFRED
Filed: 1904-06-30
Granted: 1905-05-04
Abstract: 14,733. Carolan, E. A., [Gerreral Electric Co.]. June 30. Arc lamps.-In a lamp having one electrode of a material, such as magnetite or titanium carbide or oxide, which gives a flaming arc, the opposite electrode, of copper or other non-consuming substance, is arranged so as to be self-cleaning, and the arc is struck by an auxiliary electrode, free from condensed fumes. Special feeding-mechanism is provided. The upper electrode consists of a crosshead 49, a ring 50 and axial member 55 attached thereto, and a ring 52 which can slide freely between the parts 50, 55, and is attached to pins 53, 54 sliding in the crosshead. When the electrodes move together to strike the arc, the lower electrode 20 lifts the ring 52 and engages the axial member, which may be of copper, carbon, or other substance. The separation of the electrodes allows the ring 52 to descend, so that the arc struck by the axial member is transferred to it. The lower electrode holder 19 is connected by an arm 18, rod 15, and chain 12, passing over a pulley 13, to a counterweight 11, which is normally prevented from raising the lower electrode by a dog 21 on a lever 22 pivoted at 23. The upper electrode is carried by a tent arm 47 passing through a slot in the central chimney 6 and attached to a tube 33. A rod 32, Figs. 2 and 4, attached to the core 31 of a solenoid 30, is provided with a head which has a limited sliding movement within the tube 33. A lever 56 pivoted at 57 carries the armature 59 of an electromagnet 60, and also a pawl 58 which engages the tube 33 and prevents it from sliding downwards, when the electromagnet 60 is not excited. A spiral spring (not shown) opposes the attraction of the electromagnet. Contact-pieces 42, 43 are carried by the tube 33 and core 31 respectively. Fig. 5 shows the condition of the lamp when not working. When the current is switched on, it flows between the terminals 76, 75 through a resistance coil 71, contacts 43, 42, and an electromagnet 60. The raising of the armature 59 releases the tube 33, which descends, together with the upper electrode, at a rate regulated by a dash-pot 38. During this movement, an arm 40 attached to the tube engages the end of the lever 22, depresses it against the resistance of a spring 25, and releases the rod 15 and the lower electrode, which move upwards till the electrodes meet. The current then flows through the electrodes and the solenoid 30, so that the core 31 and rod 32 are raised, first separating the contacts 43, 42, and then lifting the tube 33 and upper electrode, the lower electrode being clamped by the arm 22. If the arc length increases unduly during the operation of the lamp, a shunt electromagnet 65 attracts its pivoted armature 66 and closes a shunt circuit to the solenoid 30 through contacts 68, 69. The core 31 then descends and the above operations are repeated. The counterweight 11 has a hole, preferably rectangular, through it, to receive a similarly-shaped rod, which is attached at its ends to an insulated bracket 14 and plate 9. A second rod 8, attached to the same parts, forms a guide for a forked arm carried by the rod 15. In a modification, the upper electrode consists of a ring attached to the chimney 6 and of a rod 47 forming the starting-electrode.