GB352858A - Improvements in or relating to change speed gears particularly for motor driven vehicles - Google Patents

Abstract

352,858. Clutches ; change-speed gearing. KELLER, K., Au, St. Gall, Switzerland. Oct. 30, 1930, No. 32699. Convention date, Nov. 5, 1929. [Class 80 (ii).] A dog clutch is synchronized by an auxiliary friction clutch, the grip in which increases and afterwards vanishes automatically. The devices are preferably used in pairs controlled each by a striker 19, Fig. 2, sliding upon the driven shaft 8 of a toothed change-speed gear upon a vehicle. The driving-shaft 1 carries pinion 2 driving the countershaft and a hollow drum 12 with internal clutch dogs 18 and a split clutch ring 15, Fig. 4, held in place by cover 16. The ring 15 which is springy has doubly-inclined recesses 15<1> on its outer surface co-operating with rollers 17 in pockets in the drum 12, or with studs 17<1> formed inside the drum. The movable clutch member 20 carries external clutch dogs 18<1> and a drum 13. When the clutch is to be engaged in changing speed, the movable member is advanced by hand pressure on the striker 19. Drum 13 slips under ring 15 and there is an initial clamping stress by which ring 15 is turned relatively to outer drum 12. The rollers 17 ride up on the inclines 15<1> increasing the grip automatically and preventing further sliding of the movable member 20. The engine is declutched or throttled and the lateral hand pressure on the striker maintained. At the instant the torque in the friction parts vanishes or reverses, the forced clamping ceases, the drum 13 slips past the ring 15, and the now synchronized dogs slip into mesh. The dogs are preferably bevelled to increase the arc within which they may engage. A change-speed gear with ball-lever selective control is described.