Patent GB-404476-A (GB)
Title: Improvements in or relating to the variable speed driving gear of motor driven railroad vehicles
IPC: F16H61/02
Filed: 1933-02-13
Abstract: 404,476. Variable - speed gearing. ZAHNRADFABRIK FRIEDRICHSHAFEN AKT.-GES., Friedrichshafen - on - Bodensee, Germany. Feb. 13, 1933, No. 4423. Convention date, May 17, 1932. [Class 80 (ii).] In variablespeed toothed gearing, particularly for motordriven railroad vehicles, in which free - wheel clutches 17, 21, 23 allow the lower speeds to overrun when changing from one speed to another, and the changes are effected by claw-clutches 20, 27 having bevelled repulsion teeth and engaged through spring- means when synchronised, a driving-shaft 2 drives an aligned intermediate shaft 19 either through a speed-reducing countershaft train 12, 13, 15, 16, or directly through the clawclutch 20, the free-wheel 17 then overrunning, and two further ratios, providing four in all, are obtained by the wheels 25, 26 on the shaft 19 meshing constantly with wheels 29, 30 fixed on a driven-shaft 28. The inner hub 24 of the wheel 26 is keyed to its shaft, but the hub 22 of the wheel 25 is free on the shaft unless clutched thereto by the claw-sleeve 27, where upon the lower speed 26 overruns. A bevel reversing-train 28<1>, 31, 32 and independent controlling levers for each clutch 20, 27, interconnected with a band-brake 8 for retarding the driving-shaft 2 during upward changes, are also provided. The driving-shaft 2 is driven from the engine-shaft 1 through a spherical toothed universal joint 3, 4, and the free-wheels are of the roller type. The controlling-means comprise levers 45, 51 connected respectively through telescopic spring-links 43, 49 with the pivot-shafts 41, 47 of the strikers for the claw-sleeves 20, 27. A lever 63 moves the reversing claw-sleeve 34 through a similar resilient link 64, and this lever, when placed in a central position provides " neutral." The levers 45, 51 both carry cams 60 which, on movement of either lever beyond the dottedline position IV, Fig. 1, for normal engagement of a clutch sleeve, on an upward change, to an extreme position B, depresses a rollercarrying bell-crank 58 to apply the brake-band 8 to the driving-shaft 2. When the higher speed is engaged, the change-lever is returned to the position IV, thereby releasing the brake. The brake-band can also be applied by an independent pedal 57. Figs. 9 and 10 show a control modified to assist the operator's visual impression of the position of the levers for the various speeds, by causing the levers to reverse their sense, or direction of movement, under control of the reversing lever, according to the direction of travel of the vehicle. For this purpose, the levers 45, 51 operate their respective claw-sleeves 20, 27 through pairs of gears 66, 67 and 68, 69 and cranks 65 which are moved over their dead-centres to change the sense of the levers by movement of the reversing- lever 63, an intermediate lever 76, connected to which is also connected with lost-motion by slotted links 75 to each gear-control lever 45, 51. The control-levers are thus caused to operate in opposite senses over ranges at either side of the vertical, according to whether the lever 63 is set for forward running V or reverse running R. The brake-band 8 is now applied at both outer extreme positions B by means of eccentrics 70, on the shafts of the gearcontrolling pinions 66, 68 engaging rollers on a brake-lever 71 pivoted on the rocking-shaft of the control levers.