GB635126A - Improvements in and relating to caging signal devices for gyroscopes - Google Patents

Abstract

635,126. Gyroscopic apparatus. BRITISH THOMSON-HOUSTON CO., Ltd. Sept. 3, 1946, No. 26477. Convention date, Sept. 5, 1945. [Class 97 (iii)] Caging signal means are provided which indicate the position of the caging mechanism and whether the mechanism is locked or unlocked in the caged or uncaged position. The caging knob 10, Fig. 3, is mounted on a rotatable shaft 11 having a slotted end portion 12 in which the actuating shaft 13 of the caging mechanism is fitted. As shown, the shaft is in the caged position and is locked therein by an index pin 16 projecting from the front face of the instrument engaging a hole 17 in the knob. To uncage the gyro the knob is pulled out, unlocking it from the pin 16, and rotated counterclockwise through about 300 degrees and then pushed in, so that locking in the uncaged position is affected by a second hole 18 engaging the pin 16. , The indicating means comprise a plate 22 secured to but spaced from the dial plate 19 by means of screws passing through holes 24, 25 and screwing into the instrument face plate, the front of the indicator plate 22 being provided with suitable indicia such as the word " caged." The indicator plate 22 has lugs 26 serving as guides for the support 6 which carries the conventional model aircraft horizon index and which may be adjusted by knob 7 and pin 9. The dial plate 19 has a tongue 21 with a window 27 through which the indicator plate 22 may be viewed. A shutter 28 mounted for movement in the space between the tongue 21 and the indicator plate 22 is pivoted at its lower end which carries a cam follower member 32, Fig. 4, mounted on a right-angled projection 33 of the shutter lever. The cam follower member 32 co-operates with a three-level cam 31 mounted on the caging knob shaft 11. With the caging knob in the caging and locked position (as shown) a projection 34 of the cam follower 32 is positioned by the first level 35 of the cam so that the shutter is in its lowest position and completely unmasks the indicator plate 22. On withdrawal of the knob, preparatory to its rotation, the cam follower projection 34 rides on to the cylindrical second level 36 and remains there during subsequent rotation. In this position the shutter 28 partially masks the indicator 22. When the knob 10 is pushed in to lock the mechanism at the uncaged position the cam follower projection 34 engages the third level 37 of the cam 31 and the shutter is thereby moved so as to mask completely the indicator 22. The shutter is biassed by spring 30. The cam 31 may be adjusted by disengaging the tongue 39 of the caging lever 13 from the slot 40 and screwing the cam axially on the shaft 11 and the cam follower projection 34 may be adjusted relative to the cam surfaces by releasing screw 42 which passes into a slot 43 of the projection 33.