Patent GB-533953-A (GB)
Title: Improvements in or relating to signalling systems for use in mechanism having a plurality of stages or regimes of operation
IPC: G05D1/00
Filed: 1939-06-20
Abstract: 533,953. Electric signalling systems. CURTISS-WRIGHT CORPORATION. June 20, 1939, No. 17971. Convention date, July 9, 1938. [Class 40 (i)] A signalling and indicating system for mechanism, e.g. an aeroplane, having a number of stages of operation, e.g. starting, taking off, cruising, full power flight, landing &c. comprises a number of indicators or lamps for showing incorrect operation of various parts of the mechanism and means for selecting for operation during any particular stage only those indicators of interest at that stage. The construction of indicator for showing faults in a large number of engine operating conditions, flight controlling and landing devices is described, any indicator, e.g. of oil pressure which is of interest at all stages, being permanently in circuit. Fig. 5 is an abridged circuit diagram showing a few of the indicators for some stages. A test-button 11 operates relay 38 which completes all the lamp circuits to enable a faulty lamp to be detected, and an off-button 20 disconnects the signalling battery 36. Other buttons 14, 17, 18 operate relays 45, 50, 54 to connect up the appropriate indicators for the take-off, cruising and landing stages of the flight. The buttons are of the locking type released by pressing a fresh button. Some of the lamp circuits may be grouped and controlled by relays which may be operated by more than one,button. The main indicator may be arranged for the pilot and portions of it duplicated for the engineers &c. together with stage signals between the pilots and engineers' indicators. Indicators may be provided on the actual instruments. Transmitting arrangements at the instruments and controls. Instruments such as oil pressure gauges, thermometers &c. have limit contacts 58 connected to the lamp circuits over plugs 48. The fuel tank indications are transmitted as shown in Fig. 6 which provides for two pairs of tanks (lamps 1, 2) controlled by valves operated by handles 62, 63 which have cam discs 64 controlling switches 67-72 in the lamp circuits. If, for example, handle 62 is set to supply fuel from tank 1 (left) and this tank becomes empty, contact 74 and switch 67 complete a lamp circuit. Switches 68 and 71 provide " off " indications. Cowl flap positions (Fig. 7, not shown) are signalled in similar manner, the indications being transmitted over contacts of the " stage " selecting relays to give an indication when the flaps are in wrong position for a particular stage. The seat belt warning sign 90, Fig. 5, is illuminated during take off and landing and in rough weather flight by means of key 91, and relay 92 also operated by the key controls the lamp circuits. The de-icing arrangements comprise a key 95 controlling the de-icer and the lamp circuits are controlled jointly by a relay 96 operated over the key and an automatic indicator 98 showing when de-icing is required. The landing gear indicating arrangements 100 have an additional precautionary audible warning 105 given when either engine is throttled down by controls 103, 104. Indicating panel construction, Figs. 3 and 4. The panel, Fig. 3, has five sub-divisions at the rear of each of which is located a cell structure, Fig. 4, the end cells being provided with lamps in parallel with lamps in the elongated central cells which illuminate legends on the panel. The necessary selecting relays, plugs &c. are mounted behind the panel, and selecting keys 11 &c. at the top.