| 摘要 |
1,088,748. A/D converters. GENERAL PRECISION Inc. Dec. 1, 1965 [Jan. 6, 1965], No. 51012/65. Heading G4H. A shaft position encoder comprises a pair of magnetic code discs 58, 60 fixed to the shaft 26 and a low-speed magnetic code disc 90 coupled to shaft 26 through epicyclic reduction gearing. Disc 58 carries the least significant track 66 only. Disc 60 carries the next six tracks 68- 78, these being arranged in staggered relationship on faces B, C of the disc, as described in Specification 1,079,084. Disc 90 is identical to disc 60 but is driven at <SP>1</SP>/ 64 th of the speed of shaft 26 by means of an eccentric hub 168 fixed to shaft 26 and carrying an idler gear 164, the 64 teeth of which mesh with a fixed gear ring 202 and a further gear ring 162 on the inside of a hub 156 rotatably mounted on shaft 26, the number of teeth in rings 162, 202 differing by 1. A counterbalance 176 offsets the imbalance caused by eccentric hub 168. Core read head holders 23 are disposed adjacent the discs 58, 60, 90, the holder 23 between discs 60, 90 having coaxial bores for holding the heads for tracks 70, 700 to 78, 780. Lead and lag read heads are provided. Details of construction, assembly and adjustment are given. |
