Patent GB-668754-A (GB)
Title: Improvements in or relating to gearing transmission
IPC: F16H47/02
Filed: 1949-12-16
Abstract: 668,754. Variable-speed gearing. WOYDT, E. Dec. 16, 1949 [Dec. 20, 1948], No. 32287/49. Class 80 (ii). In a power transmission comprising a continuously-variable hydrostatic gear 91, Fig. 1, in series with a three-speed spur gear A, the gear range of the gear 91 is the same as that of each stage of the gear A, so as to secure continuous variation over the whole range of the transmission; and an auxiliary two-speed spur gear B, by-passing the gears 91 and A, is engaged during changes in the gear A so that there is no interruption of drive. Gear A comprises wheel pairs 106-110, 109-112 and 108-111, while gear B comprises wheel pairs 115-112 and 116-111, the wheels 115, 116 being geared to the driving shaft 101 at 118, 119 and the gear 91 being geared to the shaft 101 at 102, 103. The movable gears 110, 111, 112 are fast on a sleeve 113 splined on the driven shaft 114 and are moved axially by a fork 120 secured to a threaded shaft 121 engaged in an axially-fixed nut integral with a toothed wheel 122 co-operating with a pair of toothed segments 124 carried by a control shaft 125 which carries also a cam 127 operating the adjusting pin 97 of the gear 91. On turning the shaft 125, with the transmission in top speed as shown, the gear 91 is first adjusted from high to low speed, then one of the segments 124 engages the gear 122 and causes the sleeve 113 to move to the right to engage 112 with 115 while maintaining 110 engaged with 106. 110 then disengages from 106 and gear 91 is adjusted quickly to high speed, after which 112 engages 136 while maintaining engagement with 115, and finally 112 disengages from 115 as the segment 124 runs off the gear 122, leaving gear A in second speed. On further turning of shaft 125, gear 91 is adjusted to low speed, after which the second segment 124 engages the gear 122 and low speed is engaged in gear A in a manner similar to that for second speed. The Specification as open to inspection under Sect. 91, comprises also the system shown in Fig. 4 (Cancelled), wherein gear A gives two speeds through wheel pairs 14-15, 13-16, and the by-pass comprises a second continuouslyvariable hydrostatic gear 18 in series with gear B having wheel pairs 21-22, 20-23, the gear 18 being adjusted by a second cam 25 on the shaft 125, which latter carries four toothed segments 124. On turning shaft 125, with the transmission in top speed as shown, in which drive is via gears 91 and A, gear 91 is first adjusted to low speed and gear 18 to high speed, one segment 124 then engages 122 to engage 22 with 21 while maintaining 15 engaged with 14, then 15 disengages from 14 and the segment 124 disengages, leaving the drive in third speed via gears 18 and B. On further turning of shaft 125, gear 18 is adjusted to low speed and gear 91 to high speed, another segment 124 engages, 16 engages 13 while maintaining 22 engaged with 21, 22 disengages from 21 and segment 124 disengages, leaving the drive in second speed via gears 91 and A. The sequence for changing to low speed is similar. This subject-matter does not appear in the Specification as accepted.