GB438575A - Improvements in change speed gears - Google Patents

Abstract

438,575. Change-speed epicyclic gearing. AHLGREN, T. H., 32, Kungsgatan, Gothenburg, Sweden. May 13, 1935, No. 13956. Convention date, Dec. 14, 1934. [Class 80 (ii)] Relates to two-speed three-element spur epicyclic gearing suitable for cycles of the kind in which either the annulus 6 is fixed while the sun 7 is rotary, as shown in Fig. 1, or the sun 7 is fixed and the annulus 6 is rotary, as shown in Fig. 2. In each case, a carrier 3 of planet gears 5 is rigid with a driving central axle 1 which turns within a fixed bracket 13 and to which the cycle pedals 15 are secured. In the form shown in Fig. 1, the sun 7 is rigid with a sleeve 8 which is splined on a driven sleeve 2 and which carries a flange 10 with clutch recesses 9. In the position shown, in which the sleeve 10 is held at right by a spring 23, a high ratio of overdrive is imparted to the sleeve 2. A transmitting sprocket 21 upon the sleeve 2 need not therefore be made large, as is usual. To change speed to direct drive, the sleeve 8 is thrust left against the spring 23 by a control lever 18 until the recesses 9 engage over projecting ends 4 of the spindles of the planet gears 5. The drive then passes from the carrier 3 through the flanged sleeve 8 to the driven sleeve 2, the toothed gearing being idle. In the form shown in Fig. 2, the annulus 6 is rigid with the sleeve 8 splined on the driven sleeve 2. In the position shown, the planets roll on the fixed sun 7 and the annulus 6 and sleeves 8, 2 are driven at a speed which is increased, but not so much so as in the other form. To change speed to the direct drive, the sleeve 8 is slid left until clutch recesses 9 in the flange 10 engage over the projecting ends 4 of the planet spindles effecting a 1 to 1 drive, as before.