Patent GB-892061-A (GB)
Title: Improvements in or relating to belt transmissions
IPC: F16H57/035
Filed: 1960-05-05
Abstract: 892,061. Expanding - pulley gearing. PORSCHE, F. A. E. May 5, 1960 [May 27, 1959], No. 15891/60. Class 80 (2). To facilitate the removal of V-belts 22 connecting driving and driven expanding- pulleys in a tractor &c. gear, the pulleys 4, 5; 6, 7 are mounted in overhanging relationship with respect to a wall 24 of the surrounding gear ease. A disconnectable coupling 35 between a shaft 36 and the driving pulley 4, 5 is demounted to allow removal of the belts 22, and the free ends of the input and output shafts 2, 3 carrying the expanding-pulleys are connected by a strut 26 and bearings 27. Each expanding-pulley comprises sectors 19 having tapped holes 20, 21 into which are freely threaded rotatable spindles 11, 12 mounted radially in discs 4, 5; 6, 7 fast with the input and output shafts 2, 3. The outer ends of the spindles 11, 12 turn about pins 15 in the discs 4 &c. The inner ends of the spindles 11, 12 are of reduced cross-section and are formed with bevel teeth 49, 50 meshed by bevel gears 52, 53 fast upon control shafts 51 passing axially of each of the input and output shafts 2, 3. A sleeve 54 surrounds each shaft 51 and is in steep threaded engagement therewith, and also is in freely splined engagement with the surrounding shaft 2(3). Selector forks 56, 59 mounted on a transverse control shaft 58 are connected through bearings 55 with the control sleeves 54, the selector mechanism for both driving and driven pulleys 4, 5; 6, 7 being identical with the exception that the steep threaded connections between the two sleeves 54 and their associated shafts 51 are of opposite hand. The control fork 59, engaging the shaft 51 of the driven pulley 6, 7, is fast with the control shaft 58. The control fork 56, engaging the shaft 51 of the driving pulley 4, 5, is rotatably mounted upon the control shaft 58 but is constrained to turn therewith by an integral lug 69 engaged upon opposite sides by screws 70, 71, turnable in brackets 65, 66, fast with the control shaft. Turning the ratio selector shaft 58 acts through the bearing 55 to slide the two sleeves 54 axially, within their shafts 2, 3, the threaded connections with the shafts 51 turning the latter with respect to the driving and driven shafts 2, 3, so that the bevel gears 52, 53 rotate the spindles 11, 12 in the expanding- pulley discs 4 &c. and accordingly screw the belt-engaging sectors 19 in or out, to adjust the ratio. The coupling 35 comprises an externally splined connector which, in the position shown, is in engagement with internal splines in a shaft 36 and the input shaft 2, a rubber ring 41 biasing the connector leftwards of Fig. 1. A detent 40 biased radially by a spring 38 prevents axial movement of the connector. To disengage the coupling 35, a cap 45 in the gear case wall is removed to allow access to a bolt 42, so that by depressing the detent 40 against the bias of its spring, the sleeve may be withdrawn leftwards of Fig. 1 to the disengaged position. To dismount the V-belts 22, the ratio selecting shaft 58 is first turned to move the belt-engaging sectors 19 of the driving expanding pulley 4, 5 to their radially innermost positions. The screws 70, 71 in the brackets 65, 66 are then released, so that the control fork 56 effecting adjustment of the driving expanding pulley 4, 5 is rotatable relative to the ratio selecting shaft 58. The selector fork 59 is then moved by turning the selector shaft 58 to adjust the belt-engaging sectors 19 of the driven pulley 6, 7 to their radially innermost positions. The belts 22 are thereby rendered loose on the two pulleys. By disconnecting the coupling 35, as described above, any or all of the belts 22 can be removed from the gearing. In the form shown, for a tractor, an engine-driven shaft 28 drives through gears 30, 31 to the shaft 36, thence through the two expanding pulleys 4, 5; 6, 7 to the shaft 3, carrying a gear 46 meshing a gear 47 fast upon a driven shaft 48. Specification 892,062 is referred to.