GB263320A - Improvements in or relating to transmission gearing - Google Patents

Abstract

263,320. Ahlm, C. E. F. Jan. 26, 1926. Variable-speed gearing comprises an eccentricepicyclic gear train in which, for a solid highspeed drive, an eccentric bearing 15, Figs. 1 and 2, is clutched to a central shaft 1 by a toothed clutch the teeth of which are synchronized prior to engagement by friction means. Upon the loose eccentric bearing 15 is mounted a composite wheel comprising internal teeth P<1> constantly meshing with a gear P fast on the driving-shaft 1, and comprising also external teeth P<2> constantly meshing with an internally-toothed wheel P<3> fast on a driven shaft 2. The shafts 1 and 2 extend outwardly in opposite directions. The bearing 15 is sevured through a sleeve to a drum 36, which is held by a brake 38 to effect a reduced speed. The composite wheel is also adapted to be controlled through a second brake drum 20 to yield another ratio, which may be a second reduced forward or a reversed drive. As shown in Fig. 1, the connection may be through an external and internal toothed pair R<1>, R. A form in which this connection is an internal and external pair is described. In the form shown in Fig. 2, in which the third ratio must Le a reverse, the connection between the composite wabbling wheel and the drum 20 comprises crank links 30. A mass 60 may be provided to oalance the eccentric 15. The movable toothed clutch 41 is carried bv a sleeve 40 splined on the shaft 1 and presenting an external surface of two diameters connected bv a coned flank 43 to spring levers 52, Fig. 4, carried by a boss 45 fast on the shaft 1. The levers 52 carry friction clutch shoes 54, which are, in the disengaged position of the clutch sleeve, held inwards out of engagement by a raised part of that sleeve. When a clutch ring 48 is advanced, the sleeve 40 moves to the left from under the levers 52, whereupon the shoes 54 grip the drum 36 so that the teeth 41 can engage mating teeth on that drum without shock and the gearing turns solid. A form yielding two ratios only adapted for using as auxiliary or series gearing on a vehicle is shown in Figs. 7 and 8. The composite wheel at P<1> meshes with the driving gear P, and at P<2> meshes with the driven internal gear P<3>, and is supported on eccentric bearing 107. The bearing 107, which is hollow for light ness. has an extended splined boss 149 upon, and always in engagement with which, there slides a splined sleeve 125. The sleeve 125 is controlled by a striker 127 so that it may be slid to left and right to effect the solid drive and the reduced speed, respectively. When slid to the left, clutch teeth 123 on the sleeve engage clutch teeth 122 on a head 120 fast on the driving-shaft 1. When slid to the right, a dog ring 124 engages a fixed dog ring 134, whereby the eccentric is held against rotation. At an intermediate position of the sleeve 125, the eccentric 107 is braked, to the end that the sleeve 125 may be thrust into positive engagement at either end of its travel without shock. This brake comprises a shoe 153 carried by a lever 152 which is pivoted at 150 upon a ring 151 fast on the eccentric bearing 107. A mass 163 is arranged to balance the eccentric, and centrifugal force plus the action of a spring 1t;0 tends to hold the shoe against a brake surface 113 inside the gear case. The brake is disengaged, as required, by a cam surface on the clutch sleeve engaging a set screw 155 on the other end of the lever.