GB681592A - Improvements in or relating to compound indicating instruments - Google Patents

Abstract

681,592. Indicating-apparatus. SPERHY CORPORATION. Jan. 12, 1951 [Jan. 12, 1950], No. 934/51. Class 106 (iv). A compound indicating-instrument comprises inner and outer concentric dials supported respectively by inner and outer frames and a transparent member at the face of the instrument connecting the two frames and providing the sole support for the inner frame in the outer frame. A compound instrument, comprising a gyro compass and a guide indicator to assist in maintaining a predetermined path, has an outer frame 10 with an annular compass card 11 mounted thereon against which a pointer 12 is read. The frame 10 may be mounted on the instrument panel of an aircraft by screws passing through holes 13 and is enclosed behind the panel by a cover 14. An annular window 15 is secured to the frame 10 in front of the card 11 by a retaining ring 16 screwed to the frame and a flexible gasket 17 may be interposed between the ring 16 and window 15. The right -hand end of the frame 10 carries the stator 18 of an electrical receiver which controls the compass pointer 12 when connected through suitable leads and plug 19 on cover 14 to a suitable transmitter. The rotor of the receiver positions a shaft 20, forked at 21 with parallel arms 22, 23 carrying the pointer 12 and another pointer 24, both having U-shaped bends to clear the surface of the card 11, these moving parts being supported by bearings 25, 26 for 360 degrees freedom of movement. The guide indicator is a cross pointer instrument with a frame 251 including a cover 26<SP>1</SP> and window 27 and two pointers 29, 30 movable to right or left and up or down, respectively, are operated by means 31, 32 between the window 27 and a background element 27<SP>1</SP>, one of which bears centrally a representation 28 of the aircraft to serve as an index. The sole support of the frame 25<SP>1</SP> is the frame 10 to which it is connected by the window 15 being held by an outside ring 33 secured by nuts and bolts to the window 15 and frame 25<SP>1</SP>, a flexible washer 35 being interposed. Controlling signal voltages are applied to the operating means 31, 32 through the plug 19 and a junction strip 39 and thence, without interfering with the freedom of movement of the pointer 12, through leads 38 to terminals 36 fixed at the outside edge of the window 15 and connected to terminals 40 fixed at the inside edge of the window 15 by leads lying in arcuate slots 42 in the rim and inner face of the window and in radial slots 43, coinciding with indices of the compass card, the terminals 40 being connected to the means 31, 32 by leads 41. Specifications 600,186, 638,972, [both in Group XXXVIII], and 646,702, [Group XL (c)], are referred to.