GB370090A - Improvements in change speed gears - Google Patents

Abstract

370,090. Variable - speed epicyclic gearing. GESSNER, E. A., 4, Wettinerstrasse, Aue, Erzgebirge, Germany. Jan. 30, 1931, No. 3029. [Class 80 (ii).] Variable speed gearing comprises bevel gears 5 the speeds of which on their axes are varied by a gear or gears engaging anchored elements both inside and outside the pitch cone A B, C D of the gears 5. In continuously-variable gearing, shown in Fig. 1, the speed is varied by sliding friction rollers 7 radially upon a spider 4 which supports the main gears 5. The spider 4 is fast on a driving-shaft 1 and the rollers 7 engage the face of a non-rotary disc 17 pressed axially by a spring 19 adjustable from a hand-wheel 18. The driven element is a pulley 2 secured to a revoluble drum 20 loose on the shaft 1 and gaving two gear rings 21, 22 adapted to be enmeshed alternatively with the main bevel wheels 5. The speed ratio is controlled from a hand-wheel 11 through a screwed tube 12 connected by toggle links 9 so as to move the rollers 7 in unison. When the engagement of the friction elements 7, 17 is on the lines A B, C D, the pulley 2 is not driven. As the rollers are moved outwards or inwards, the speed of the pulley increases forwardly or backwardly, respectively. On moving the drum 20 and the pulley 2 to the left by way of a control rod 25, a different range of speeds is imparted to the pulley. An arrangement is described by which the disc 17 is driven at a constant speed to effect another range of speeds of the pulley 2. In an arrangement variable step by step shown in Fig. 5, trains of bevel gears 35, 36 take the place of the disc and roller gearing of Fig. 1. Driving and driven shafts 1, 2 are in line, the drum 20 sliding on the latter. The nested gears 36 are alternatively braked. When gear 36a is braked, there is no drive. When gears 36b, 36c are braked, increasing forward speeds result. When gear 36r is braked, the drive is reversed. These gears are connected by sleeves to drums 45 which are braked selectively by sliding a sleeve 49 upon a fixed rod 54 from a pedal 51. Each drum is encircled by a band brake 46, Fig. 6, with a control arm 48 resting on the sleeve 49. The sleeve 49 has a doubly-coned swell 50, Fig. 7, which slides under an arm 48 to apply the corresponding brake. The sleeve 49 is locked by the arm 48 engaging a notch 50a in the swell 50. An arrangement is described with toothed gear pairs instead of the brakes through which power may be transmitted alternatively when the drum 20 is temporarily locked against rotation, instead of being itself the driven member.