361,663. Time of running of vehicles or machines. NORRIS, G. THORNTON-, 197, Lauderdale Mansions, Maida Vale, London. Dec. 18, 1930, No. 38216. [Class 106 (iv).] A device for integrating intermittent time intervals particularly for use on aircraft for indicating actual flying time, comprises a time mechanism having fluid pressure controlling means to allow of intermittent operation, and means whereby the resetting action for the indicating hands serves automatically to rewind the clockwork. As shown in Fig. 1, a casing 10 accommodates an elastic capsule 11 communicating with a nipple 13 connected to a pilot tube or other fluid pressure device. The free side of the capsule is formed with a plate 52 adapted to co-operate with an adjustable screw 53, Fig. 2, on a bell-crank lever 49 pivoted on lugs 51 on a frame plate 50. The outstanding arm of the bell crank is coupled by means of a spring-controlled link 55 to an arm 56 pivotally mounted by means of a sleeve on a spacing member 58. The free end of the arm is provided with a wire 59 normally engaging the teeth of an escapement wheel 45 of a spring motor or clockwork mechanism 30. The spring and associated ratchet mechanism 31, 32 are mounted upon a winding arbor 33 with a left-hand threaded portion 34 carrying an operating shaft 35 controlled by a right-handed spring 36. The shaft 35 carries a short radial hand 37, Figs. 1 and 5, secured thereto by a collar 38 while an auxiliary longer hand 39 is frictionally mounted thereon by means of a spring 40. The hands indicate on a dial plate 25 the trip duration and are usually superimposed, but a pin 43 extending from the dial may arrest the movement of the hand 39 while the hand 37 continues its movement. These hands are set to zero by operating the shaft 35 through the knob 41 the hand 37 co-operating with a lug 44 on the hand 39. During this anticlockwise movement the spring 30 is rewound. The times of flight are summed up on an integrating mechanism, Fig. 3, comprising a counting train on spindles 61, 64, 65, 66, driven by the spindle 61 through gearing from the wheel 31. The units wheel 67 is driven by a pin 72, Fig. 4, on the spindle 61 engaging a wide slot 73 in the hub of the wheel thus introducing backlash to allow the reading to be maintained for an increased period, detent pawls 71 being provided to justify the wheels. In Fig. 1 the instrument is shown supported by a bracket 18 with a cross-piece 20 for attachment to any convenient part of the aircraft or other vehicle or machine. For mounting on a dashboard the casing 10 may be supported by a U-shaped strip passing over the nipple to the back of the dashboard. The dial plate 25 is held in the casing by means of a bezel ring 26 and glass cover-plate 27 secured by a screwed ring 28 rotation of the elements being prevented by an L-shaped pin 29 located in slots cut in the several components.