Patent GB-190318624-A (GB)
Title: Improvements in Electric Lamps of the character known as Vapour Lamps or Vapour Arc Lamps
Inventor: BASTIAN CHARLES ORME
Filed: 1903-08-29
Granted: 1904-08-25
Abstract: 18,624. Bastian, C. O., and Salisbury, A. E. Aug. 29. Vacuum tubes; incandescent lamps. -Relates to mercury-vapour lamps in which the tube is horizontal when the current is off, and the mercury is consequently continuous between the electrodes, the starting of the lamp being effected by automatic tilting, to cause the mercury to divide. Fig. 1 shows a lamp in the inactive position, with electromagnetic starting- apparatus. The globe m is attached to a hood k, the base-plate l of which is provided with slots l<1> for the moving parts. A fixed bracket i carries the solenoid h and also a second bracket i' which holds the pivot d' about which the solenoid, when energized, turns the bar d by means of the core g, and links f<1>, f, the motion being controlled by a spring o and stops e. Arms b, c on the bar hold in clips b<1>, c<1> the lugs a<6> on caps a<5>, a<4> to which the ends of the vacuum tube a are secured, and, when tilting occurs, the mercury runs into and fills the reservoir a<1>, and an arc is struck between the mercury in the tube and that in the cross-tube a<2>, the condensing -chamber a<3> ensuring that the electrode x shall always be covered with mercury. Modified tubes are described for lamps of this type in which the condensing-chamber is fitted with an adjustable screw sleeve, affording means for altering the amount of surface available for cooling by radiation, and also tubes having contractions in the part a introducing a dash-pot action. Fig. 7 shows a circular form of tube a, combined with an incandescent filament lamp j, j<1> in series with the mercury lamp, the steadying resistance being arranged as a coil c<2> within the lamp, so that when the arc is struck the resistance of this coil is diminished. Striking is performed either by a solenoid and core g, g<1> moving a bar f, in one piece with the arms carrying the tube, and pivoted at d<1>, or by a heating-coil k<1> within bellows k, whereby the top-board and rod k<2>, k<4> are forced upwards, or by a hot wire in series with the lamp, the length of which determines the position of a weighted bar. In the type shown in Fig. 9 there is also an incandescent lamp j, j<1> in series with the tube a, the latter resembling in form that first described and being preferably provided with a resistance c', the whole swinging with the bar n<1> about pivots n<X> according as the compound bar p is heated and curved by its surrounding coil p<1>, and forces the point p' down on to the bar. It is stated that the reduction in resistance of the lamp which occurs soon after striking may be compensated for by a switch throwing in resistance, or by alteration of potential ; and that lead glass and pure mercury are preferably used for the tubes, with the addition of potassium if a yellower light is required. The carbon filaments may be similar to those described in Specification No. 1995, A.D. 1903. The bore of the tube a is preferably small, and as the tube a' fills, it overflows and thus replenishes the mercury at the other electrode.