GB884893A - Improvements in or relating to attitude indicators for aircraft - Google Patents

Abstract

884,893. Aircraft attitude indicators. COFFING INDUSTRIES Inc. Aug. 24, 1959 [Aug. 28, 1958], No. 28890/59. Class 4. An aircraft attitude indicator comprises a gyroscope 18 pivoted about a horizontal lateral axis to a gimbal ring 19 pivoted about a fore-and-aft axis in a casing 16, a model aircraft 11 connected by a lever 26 to the gyroscope so as to pitch in response to pitching of the aircraft, and a terrain reference 12 secured to the gimbal ring, so that the model pitches and rolls with respect to the reference as the aircraft pitches and rolls. Fig. 3 is a side view and Fig. 4 a plan view, both in partial section. The lever 26 is attached by a clamp 25 to the cageing lever 24 of the gyroscope, which extends from the case 17 through an arcuate slot 24a in the gimbal ring. The model 11 is universally pivoted at its tail to a transparent viewing bubble 14 on the indicator face, and is connected at its nose to an arm 28 on lever 26 by an eyelet which can slide longitudinally relatively to the model. The terrain reference 12 is supported by a bracket 30 from the gimbal ring, and supports a black background 31, on which angle of pitch indicia are marked. The reference 12 has a pointer 34 indicating the degree of roll on a scale marked as a flattened part 36 of the bubble 14. In modifications in which the model is more sensitive to aircraft pitching, the model is supported between its ends, and the tail is free, the angle of pitch being read off against the model tailpiece from a scale on the bubble 14. This support may be manually adjustable to trim the model to correspond with the trim of the aircraft. The lever 26 may be pivoted to the gimbal ring, and have a slot engaged by lever 24, see Fig. 13 (not shown). In a helicopter, a helicopter-model is used.