| 摘要 |
1,150,702. Linkwork. ELLIOTT BROS. (LONDON) Ltd. 26 Jan., 1967 [5 Feb. 1966], No. 5162/66. Heading F2K. [Also in Division all Linkwork producing an output rotation of a shaft 11 related in a predetermined manner to an input rotation of a shaft 12 comprises a crank 15 secured to shaft 12 and connected by a link 16 to a lever 17 intermediate its ends, lever 17 having on one end a roller 18 engaging an adjustable fixed cam 19 and the other end pivoted to a bell-crank 20 rotatable about the shaft 12, a roller 22 on the bell-crank engaging the end of a crank 25 secured to the shaft 11, a spring 26 connecting the cranks 15, 25 to urge the rollers 18, 22 against cam 19 and crank 25, respectively. Roller 22 and shaft 11 are approximately equidistant from shaft 12 so that the output rotation is approximately half the corresponding input rotation. The ratio is adjustable by moving the roller 22 along a radial mounting slot 24 in bellcrank 20. The cam 18, which is substantially a circular arc centred on shaft 12, is a flexible strip mounted on a frame 28 by adjustment screws 27. The end of crank 15 is split and the portion 15a to which link 16 is pivoted is adjustable relative to the more rigid portion 15b by screws 29 for phase adjustment between shafts 11, 12. The linkwork is used in a servo loop of a pressure gauge to provide for its calibration. In Fig. 4, expansion or contraction of a capsule 31, supplied via a line 33 with Pitot minus static pressure and housed in a sealed chamber 32, is converted into rotation of a jewel-mounted shaft 38 by a linkage comprising a member 34, a bimetallic temperature correction element 35, a link 36, and an arm 37. The shaft 38 carries the armature 41 of a transducer 42 having laminations 43 and a coil 44. The error signal from the transducer is fed to a servomotor (not shown) to act via a gear-wheel 46 and the linkage 12-25 to rotate a shaft 11 on which the transducer is mounted until the error signal is reduced to zero. The output is taken from the gear 46 which is connected to further servo arrangements to provide an altitude reading and/or to provide outputs for use in automatic control of an aircraft. |
