Patent GB-190907471-A (GB)
Title: Improvements in or relating to Electric Arc Lamps.
Inventor: JABURG HENDRICUS JOHANNES JACO
IPC: H05B31/00
Filed: 1909-03-29
Granted: 1910-03-03
Abstract: 7471. Jaburg, K. J. J. March 28, 1908, [Convention date]. Arc lamps; arcl a m p electrodes.- Two abutting inclined electrodes a support each other and a third electrode c. One of the electrodes a may be replaced by a thin rod of carbon or metal. The holders of the abutting electrodes slide on fixed rods g and on arms k attached to a centrallyguided weight, to which may be pivoted the holder of the vertical electrode c. The electrode c passes through a slot in the base-plate l and a hole in a movable cover-plate n, connected by a lever q and a rod p to the core of a differential solenoid s. The weight of the core is partly borne by an adjustable spring z<1>. Current is supplied to the carbons at the points where they pass through the base-plate, the inclined carbons being in series with separate resistances, to equalize the currents. The shunt coil of the solenoid has one terminal connected to one of the carbon-holders e, and the inclined electrodes a are loose in these holders, so that, when nearly consumed, they fall out and break the shunt circuit. The ejection of the stumps is aided by bevelled blocks actuated by springs within the holders, and the lower adjacent corners of the holders are bevelled. The abutting electrodes may be of triangular section, with half-cores in their contiguous faces. The Specification in the original form, as open to inspection under Section 91 (3) (a), comprises also the following subject-matter :-An arc-cnntrolling electro-magnet may be connected in series with each abutting electrode, so as to correct the obliquity of the field due to the current in that electrode. A permanent or electro-magnet may have its field normally shunted by a pivoted arm to an extent adjustable by a screw. When the electrodes are burnt short, one of the holders engages an extension of the arm and tilts it so that the field of the magnet is strengthened and blows out the arc. When one abutting electrode is replaced by a thin rod, this conveys the current to the main electrode, so that the circuit is broken when the rod is consumed or the electrode arrested ; the second main electrode is moved by a slide in an oblique direction, to aid the detachment of slag from the electrode points. This slide is actuated by a rod, a series electro-magnet, and a weighted lever, the lever, and optionally the core, having spring connexions to the rod so that a small arc is formed at first when current is switched on. The electrodes may be of large sectional area, the vertical one being negative in this case. To facilitate the transition of the arc from one abutting electrode to the other, air-passages or special cores may be provided near their adjacent sides, or the ordinary cores may be displaced towards each other. Half-round electrodes with similar cores, or flattened electrodes, may be used. To diminish the bending strain on the abutting electrodes, they may be pressed together by projections from the economizer near their ends, and their holders may be rigidly attached to horizontal arms which slide past each other through the weight, the arms on the last-named being dispensed with. An electrode to rest on a stop may be of semicircular section, or laterally set off near its upper end, so as to fall and break the circuit when nearly consumed. This subject-matter does not appear in the Complete Specification as accepted.