Patent GB-256704-A (GB)
Title: Improvements in or relating to lighthouse and like lamps
IPC: H05B39/10
Filed: 1925-05-14
Abstract: 256,704. Gas Accumulator Co. (United Kingdom), Ltd., and Steel, R. R. May 14, 1925. Burners, mounting, adjusting and controlling. - In a lighthouse or like lamp, a defective electric lamp bulb is removed bodily from the lens system and is automatically replaced by a gas burner if the electric current fails, or there is no lamp bulb available, the lamp bulbs and the gas burner being adapted to be brought into the focus of the lens in sequence by a motor or by motors individual to each under the control of electromagnetic means. Fig. 2 shows one arrangement in which the replacement of the light source is effected by means of a rotatable cam ring 7 or element engaging parallel-motion linkages 4 supporting the lamp bulbs and the gas burner and driven by a falling weight, the ring 7 being arrested, when a serviceable light source is installed at the focal point of the lens, by means of electrically-controlled stops 23, 12. The shunt coil 15, which operates the stop 23, is disengaged when the contacts 17 are broken by lowering a lamp bulb, and the stop 23 bears against the cam ring 7 and locks it when the gas burner is in position, the lowering of the burner opening its valve 25. The main flame of the burner is extinguished automatically during daylight by a sun valve 26. In another arrangement, the linkages 4, Fig. 3, supporting the light sources are each displaced by the upward thrust of a piston in a cylinder 28, 27 when gas is admitted thereto. The gas is supplied through a valve casing 29, when electromagnetic means, such as a solenoid 33, is energized to valve casings 31, 32 connected to the cylinders 28, 27. The chamber of the valve casing 31 to which gas is first admitted is separated from a central chamber 36 communicating with the cylinder 28 controlling the gas burner by a singleseated valve, a flexible diaphragm separating the chamber 36 from a third chamber 39 to which gas is conducted by way of the chambers 39<a>, 39b 39<c >of the other valve casing 32.' Each casing 32 contains a double-seated valve which is forced by a spring to isolate from the system the chamber supplying the corresponding cylinder 27. Initially, the gas burner 19 is raised by the pressure of the gas until the gas passing through the chambers 39<a>, 39<b>, 39<c> of other valve casings to the chamber 39 acts through the diaphragm to close the valve and imprisons gas in the cylinder 28. The double-seated valve of the valve casing 32 for controlling the first lamp bulb is then operated 'by a solenoid 42i to supply gas to the corresponding cylinder and to isolate the portions of the pipe system beyond. If the lamp bulb or the current supply fails, the solenoid 33 is disenergized, the valve casing 29 is opened to the atmosphere, and the cylinder 27 is temporarily exhausted so that the lamp bulb is raised. Simultaneously the solenoid 43 of a stop for arresting the movement of a rotary switch 44 is disenergized, thereby breaking the circuit through the solenoid 42 and shortly after closing the solenoid 45 of the valve casing of the next cylinder 27. After the last bulb is removed, the diaphragm chamber 39 is vented, the single-seated valve is opened, and the gas burner descends into the operative position. If the stop mechanism becomes inoperative, the solenoid 53<a> of a brake normally energized to render the latter ineffective allows it to act. In a third arrangement, the lamps are operated electrically, solenoids acting directly or indirectly on the linkage.