Patent GB-190405892-A (GB)
Title: Improvements in or relating to Electric Lamps of the Character known as Vapour Lamps.
Inventor: BASTIAN CHARLES ORME
Filed: 1904-03-10
Granted: 1905-03-10
Abstract: 5892. Bastian, C. O. March 10. Vacuum tubes.-Vapour lamps, constructed with electrodes of dissimilar materials such as iron and mercury, so that current will only flow readily in one direction, are arranged in parallel in an alternating-current circuit, but with dissimilar electrodes connected to the same lead. Each of the two lamps or set of lamps then carries the current in one direction only. A corresponding arrangement may be adopted with multiphase currents. Vapour lamps of any kind may be enclosed in sealed glass envelopes containing hydrogen or other gas which rapidly dissipates heat by convection or conduction ; or, according to the Provisional Specification, such envelopes may be exhausted in order to assist in maintaining the vacuum in the lamp, when the lamp itself is of qnartz or glass having a coefficient of expansion different from that of the leading-in wires. Flickering may be decreased by increasing the current density over the negative electrode, or by deflecting the arc stream near the negative electrode against the wall of the tube by a magnetic field, which may be that of the solenoid or magnet used in starting the lamp. At the part of the lamp where most heat is developed an enlargement adapted to act as a radiating-chamber may be provided. Lamps are constructed with one or both electrodes movable, and arranged so that, when the arc is struck by means of a bridging- piece withdrawn by the action of a series solenoid, one or both electrodes recede against the action of gravity so as to lengthen the arc. This receding movement may impart an overbalancing or other motion to the lamp itself. The bridging-piece may be solid, or of mercury contained in a capillary tube or suitable vessel ; or one mercury electrode may be caused to overflow into contact with the other by means of a float withdrawn by the series solenoid. The negative electrode in a mercury lamp is contained in a receptacle so arranged that the mercury which is transferred by the current from the positive electrode may readily run back to the latter. When vapour lamps are used in series with an incandescent electric lamp in shunt across each or any of them, the current through the incandescent lamp is stopped, when the vapour lamp circuit is opened, by means of a contact device, advantageously operated by the starting magnet of the vapour lamp. There may also be provided another contact device operated by the movement of the mercury electrode, so that the incandescent lamp is only lit after a definite length of arc has been attained. In one form of mercury lamp, the bridge-piece f is of iron wire, and a space e is provided into which the mercury electrode c is displaced as the arc lengthens. The lamp is supported by arms b from a movable or fixed support. The Provisional Specification states that in packing the lamps for transport, they are arranged in a case in such a way that they can revolve on their axes. The case is so constructed that it cannot readily be put into position to allow of displacement of the mercury in the lamp from one end to the other, for example by prolonging the bottom of the case, in the direction of the length of the lamps, beyond two opposite sides. The lamps are preferably flexibly suspended within the case.