GB417389A - Improvements in or relating to accelerometers or the like - Google Patents

Abstract

417,389. Accelerometers; indicating- apparatus. SINCLAIR, H., 6, The Crest, Surbiton Hill, Surrey. April 1, 1933, No. 9893. [Classes 106 (iii) and 106 (iv).] In an accelerometer for motor vehicles indicating both positive and negative accelerations, the scale ratios on opposite sides of the zero position change abruptly to allow for the negative values being generally much higher than the positive values. The shaft 2 which is driven from some moving part of the vehicle drives a flywheel 7 in the opposite direction through an epicyclic gear consisting of a sunwheel 4 directly driven from the shaft 2, an annulus carried by the flywheel and planet pinion 5 carried by a frame 6 with spindle 8 freely mounted on ball bearings. Movement of the carrier 6 in one direction is resisted by a spiral spring 11 fixed at its outer end 12 to the casing. The inner end of this spring bears against a fixed fin 14 and a pin 13 on the planet carrier so that it can only resist rotation of the carrier in the anti-clockwise direction. A similar spring 10 of different strength controls rotation of the carrier in a clockwise direction. A pointer 15 on the planet carrier spindle 8 points to zero when the shaft 2 is rotating at uniform speed, but when the shaft is accelerated or retarded the pointer moves in one direction or the other according to the yielding of one or the other of the two springs 10, 11. Specification 20676/13, [Class 106 (iii)], is referred to.