Patent GB-1164653-A (GB)
Title: Improvements relating to Continuously Variable Speed Transmissions
Inventor: RHEINLANDER PAUL
IPC: F16H29/04
Filed: 1967-07-11
Abstract: 1,164,653. Variable-speed ratchet gear. THERMO-INDUSTRIE G.m.b.H. & CO. 11 July, 1967, No. 31886/67. Heading F2D. A continuously-variable-speed ratchet gear for driving control apparatus comprises one or more driving cams of continuously varying profile in its/their axial direction and a plurality of pairs of follower rollers positively constrained to engage and follow the cam or cams and carried by intermediate members which reciprocate or oscillate out-of-phase with one other and are so coupled to a driven shaft as to rotate the latter at a constant selected speed, the cam or cams and the follower rollers being relatively adjustable in the cam axial direction for ratio variation. As shown, each of two driving cams 3, 4, phased at 90 degrees, have at their opposite axial ends maximum lift and no lift (circular, neutral) contours, the corresponding contour points being joined by straight lines. Two pairs of follower rollers respectively diametrically opposed with respect to, and positively engaging, the cams 3, 4 are journalled in reciprocating intermediate members 5, 6 acting on a driven shaft 19 through racks and pinions 15-18, 20-23 and one-way clutches. As shown, the cams 3, 4 are fast on a shaft 2 slideable in a hollow driving shaft 1 and axially adjustable by a hand-lever 12 acting on a ring 11 freely rotatable with respect to the shaft 2. Alternatively, the shaft 2 may be fixed and the intermediate members 5, 6 movable axially of the cams. For constant-speed driven shaft rotation, the cams must produce constant follower velocity over at least 90 degrees cam rotation. The one-way clutches between the pinions 20- 23 and the driven shaft 19 may be reversible for reversal of driven shaft rotation. The oneway clutches may be replaced by toothed drives the mesh of which is determined by cams. In Fig. 4 (not shown), the rollers of each pair of axially movable follower rollers (27), (28) are axially staggered in respect of and engage a driving double cam (25), (26) and are carried by pairs of intermediate member lever arms (33), (34) fast on a hollow shaft (36) which is coupled to the driven shaft (35) in one direction of lever arm oscillation by a ratchet-toothed clutch (37), (38) engaged by a driving shaft operated cam (40). Several, e.g. three, sets of cams, rollers and hollow shafts are arranged on driving and driven shafts (24), (35); alternatively, the rollers may all engage a common double cam, the pairs of lever arms being mounted on shafts spaced at 120 degrees and driving a common final driven shaft through gear-wheels. In a modification of the Fig. 4 (not shown) embodiment, there is provided a further driven shaft, the two driven shafts being drivable at different speeds, the common driving shaft being axially fixed and the individual driven shaft speeds being adjusted by axially shifting the oscillating lever arms. In Figure 5, the two halves of each of a series of double cams 25, 26 are mounted on separate shafts 41, 42 driven, e.g. through gearwheels, from a common driving shaft. Each cam half is engaged by rollers 46, 47 of separate lever arm pairs 43, 44 connectible to driven shafts 49, 50 through one-way clutches. The driven shafts may be driven at different speeds by adjustment of the driven shafts. The cams may be so arranged that, to avoid shock on clutching, the intermediate members speed up just before clutch engagement.