| 摘要 |
1470423 Altimeters SMITHS INDUSTRIES Ltd 26 Aug 1975 [23 Aug 1974] 37215/74 Headings G1L and G1S [Also in Division G4] An instrument such as an altimeter in which a pointer 19 moves over a scale 20 providing a fine indication and a second scale 26 shows the number of revolutions made by the pointer to give a coarse indication, has the second scale visible through an aperture 24 at the zero 22 of the first scale and moving in the opposite direction to the pointer 19 so that during transition between coarse units, the pointer indicates generally on the scale 26 between which of the coarse units the total reading lies. The aperture is preferably wide enough to expose at least two of the coarse scale numerals. The reading on the altimeter dial shown is 7,950 feet, the scale 26 being marked in 1,000 feet units and each revolution of the pointer 19 indicating a 1,000 feet. A step 29 may be provided in the aperture 24 to obscure a sub-division graduation and reduce further the possibility of misreading. The scale 26 may be on a part transparent disc behind which an adjustable indicator 31 of air-pressure at ground level is visible.
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