GB533607A - Improvements in or connected with controls of aircraft - Google Patents

Abstract

533,607. Linkwork. SHORT BROS. (ROCHESTER & BEDFORD), Ltd.. and HART, S. G. Oct. 25, 1939, No. 28649. [Class 80 (iii)] [Also in Groups XXXIII, XXIX and XXX] In order to compensate for changes of temperature a control cable for an aircraft is passed over two fixed guides between which is located a movable guide adapted to be displaced transversely of the cable to take up slack or to relieve increased tension. The movable guide may be actuated manually or automatically in accordance with changes of temperature, or it may be urged transversely of the cable by a spring in conjunction with a dashpot which resists movement due to momentary changes of tension in the cables. Fig. 2 shows a device, for several cables of similar length, comprising a frame 10 with two sets of guide pulleys 11 a fixed distance apart. Jockey pulleys 12 are carried by arms 13 on a shaft 14 from which depend arms 15 connected by a cross-bar 16 movable by a screw 17. The control cables are shown as lengths of chain 28 passing over the pulleys and connected by links 29. The screw 17 is turned by a shaft 18 actuated from the pilot's cockpit by a hand-wheel with which is associated an indicator drum which may be calibrated in temperatures so that the device may be adjusted in accordance with the readings of a thermometer. The jockey pulleys may be mounted and actuated individually when the cables are of different lengths. Fig. 4 shows a modification in which the jockey pulley 12 is moved by a servo-motor 31, the pilot valve of which is controlled by a bi-metallic strip 30. A locking device not shown, immobilizes the pulleys 12 should the fluid pressure fail. Alternatively the bi-metallic strip may move the brushes of a reversible electro-motor for rotating a shaft similar to the shaft 18.