GB687849A - Improvements in or relating to visible indicators - Google Patents

Abstract

687,849. Electric indicators; visible signalling. FAIREY AVIATION CO., Ltd. June 30, 1950 [Aug. 23, 1949], No. 21899/49. Classes 40 (i) and 118 (ii). A visible indicator comprises a window behind which an indicator plate is movable from an obscured to a displayed position, and a shield (which may be integral with the indicator plate) simultaneously movable away from a position obscuring the window by an axially displaceable rod having an offset lug pivotally attached to the shield. In Fig. 2, a dashboard indicator for e.g., fire in an aircraft engine comprises a cylindrical casing 10 with a part-spherical end window 11 behind which a part spherical shield 17 is rotatable through 90 degrees about bearings 20 engaging the parallel ears 19 of the shield whose surface is extended into an indicator 25 bearing a legend exposable on rotation of the shield by the attraction, by a solenoid 22, of a spring- biased armature 16b carrying an operating rod 16 having an offset lug 16a pivotally attached to the shield at 21. In Fig. 3 (not shown) the axial rod directly operates the indicator plate and a separate pivotal shield is removed when the indicator approaches the window. In Fig. 4, the shield 17 and extension 25 are mounted.as before behind the window 11, and the operating rod 16 is attached to a spring-loaded piston 28 reciprocable within the casing 10 by hydraulic pressure along the line 32, which is connected to a remote cylinder 34 within which a piston 35 is slidable by the operation of the component to which the indicator is related, e.g., an aircraft control surface Fig. 5 (not shown). The indicator may similarly be operated by an aircraft undercarriage, or by the fluid pressure in a hydraulic line through a reducing valve Fig. 6 (not shown). Mechanical and pneumatic operation of the indicator are mentioned.