Patent GB-458175-A (GB)
Title: Improvements in or relating to route lighting apparatus for use on vehicles
IPC: F21V14/08
Filed: 1935-03-11
Abstract: 458,175. Anti - dazzle screens for vehicles. HENROTEAU, F. C. P., 62, Rue PÚre Eudore Devroye, WoluwÚ St.-Pierre, Belgium. March 11, 1935, No. 7600. Void [Abridged as open to inspection under Sect. 91 of the Acts, Aug. 10, 1936]. [Class 103 (ii)] [See also Groups XI and XXXVIII] A road vehicle, ship, or aircraft is provided witl means to vary the nature e.g. colour or polarization of the light projected by the vehicle lamps according to the geographical directior of motion of the vehicle, anc to vary the nature of the light visible to the driver. A member, e.g. a magnetic or gyroscopic compass, giving a fixed geographical standard direction and associated elements undergoing the changes of direction of the vehicle and extending over sectors corresponding to those directions in which light of a particular character is to be used., may be used to control the character of the light. In the case shown, the colour of the light projected and viewed is altered by altering the colour of liquid screens in the headlamps and windscreen. For instance, liquids of three different colours, e.g. orange, olive green, and greenish blue may be introduced respectively into spaces 64, 73, 74 between glass walls at the front of the headlamps, and into corresponding spaces in the windscreen. The delivery or removal of liquid is controlled by pumps comprising cylinders 58, 59, 60 and pistons 55, 56, 57. The pistons each consist of a plate and a flexible diaphragm fixed to the cylinder. On one side of the piston is the coloured liquid which can be passed through a tube to one of the spaces 64, 73, 74. On the other side of the piston is air, which can be passed through a tube to the corresponding space in the windscreen, the space 64 and the space in the windscreen intercommunicating. The pistons are connected to cranks 51a, 51b, 51d on a shaft 51 which is driven by an electric motor 35. The cranks have successively a phase difference of 90‹. The dimensions of each piston and its stroke are such that during the last quarter of a turn in which the liquid is delivered in each case, the liquid is delivered into the corresponding spaces in the lampscreen and windscreen. The motor 35 is controlled by a photosensitive device, thyratrons and rotary switches. In controlling apparatus of this kind, a parallel beam 8 is projected onto an aluminium disc 13 fixed to a magnetic compass 14. The disc and needle have thicknesses inversely proportional to the densities of the materials constituting them. A small aperture 13a in the disc 13 allows the passage of a beam 8a to a photo-electric cell 15 with a grid-like anode 16 and a triple cathode 17 composed of three sectors 17a, 17b, 17d separated by insensitive zones 18, 19, 20. Instead of a single cell with three cathodes as shown, a plurality of cells may be circularly arranged. The three cathodes 17a, 17b, 17d are connected directly to the grids 25a, 28a, 31a of three thyratrons 25, 28, 31 and the anode 16 is earthed and is connected through the batteries 23, 26, 29 and resistances 24, 27, 30 to the grids. The cathodes 25b, 28b, 31b of the thyratrons are earthed and heated by a battery 32. The anodes 25d, 28d, 31d are connected to rubbing contacts 40, 41, 42 of the rotary switches 36, 37, 38 mounted on a shaft 46 which is driven by the motor 35. The switches comprise conducting discs having insulating pieces 36b, 37b, 38b with successive phase differences of 90‹, the arrangement being such that each insulating piece comes below its corresponding rubbing contact when the piston in the corresponding cylinder is at the end of its delivery stroke. The conducting discs are connected to the motor 35. When, for instance, the beam 8a falls on the sector 17a, the grid 25a is made positive and allows the passage of current through the thyratron 25. This operates the motor 35 until the insulating piece 36b comes below the rubbing contact 40. In this position the liquid from the cylinder 58 is delivered to the lamp and windscreen. Fixed to the shaft 46 is a fourth conducting disc 93 with an insulating piece 93b which is displaced 90‹ behind the piece 38b. When a switch 91 is set to complete the circuit through the disc 93, the motor operates so that all three liquids are withdrawn from the screens and white light only is projected and observed. The insensitive zones 18, 19, 20 are to prevent repeated changes of colour for slight road direction changes. To avoid difficulty due to the beam Sa falling on one of these zones initially, the cathodes 17 are initially rotated against the action of a spring 92 by a lever 87 and an electromagnet 89. Photo-electric cells and selenium cells, photovoltaic cells, cells of blocking Grondahl type, or thermo-electric piles may be used, with amplifiers or electromagnetic relays. The coloured liquids may be potassium bichromate dissolved in water and methyl alcohol, mixtures of that solution with copper sulphate dissolved in water, ammoniacal water, and methyl alcohol.