Patent GB-580403-A (GB)
Title: Improvements in or relating to speed transmissions
IPC: F16H29/20
Filed: 1943-03-03
Abstract: 580,403. Variable-speed gearing; clutches. STEVENS, A. H. (Weskenson Corporation). March 3, 1943, No. 3505. [Class 80 (ii)] Continuously-variable-speed gearing comprises beams 82, 112, Fig. 29, which are oscillated about fulcrums 84, 114, by cams 30, 31, Figs. 9, 13, with or without pinion-andrack gearing 32, 34, 35, by a driving shaft 24, and which drive a shaft 25 through rack-and-pinion gearing 104, 134, 105, 109 and one-way clutches 110, 138. The position of the beam fulcrums 84, 114, is varied to vary the speed ratio and to give a reverse. For a one-to-one drive the shafts 24, 25, are directly coupled together by a clutch 28 and the reciprocating and oscillating parts are kept stationary by uncoupling a clutch 27. The gear control shafts 211, 231, 342, may be actuated manually or automatically. As shown, slides 40, 41, are reciprocated on fixed guide rods 61, 62, 71, 72, by a mutilated gear 32 and racks 34, 35, and by cams 30, 31, which engage follower rollers 36, 37 (not shown), 38, 39, on swing- ing links 42, 43 (not shown), 44, 45, connected to the slides 40, 41. The cams 30, 31, and gear 32, are carried on a sleeve 26 which is clutchable to the driving shaft 24 by a clutch 27. Beams 82, 112, are pivoted at 81, 111, to the slides 40, 41, and at 91, 121, to reciprocating guides 93, 123, guided on fixed rods 94, 95, 124, 125. The parts carrying the pivots 91, 121, are slidable in the beams 82, 112 The beam fulcrum pivots 84, 114, are carried in slides 85, 115, screwed on rods 86, 87, 116, 117, the beams being connected to the pivots by slidable housings 83, 113. Simultaneous adjustment of the pivots 84, 114, is obtained by rotation of the rods 86, 117, upon rotation of a shaft 342 having a gear 341 meshing a gear 154 engaging a gear on each of the rods. The driven shaft 25 is connected to an adjacent shaft portion 336 by a torque-limiting clutch 239 comprising a plate 331 having a series of rollers radially journalled therein and a plate 332 with a corresponding series of radical recesses. The plate 332 is urged against the plate 331 by a spring 333. When the safe torque is exceeded the rollers and recesses slip over one another. The clutches 27, 28, are of the jamming roller type and are alike. Clutch 28, Figs. 13, 16, has three pairs of rollers 279, 280, pressed apart by springs 295 and located between a cylindrical bore 274 in a body 197 fixed to the shaft 25 and the surface of a sleeve 272 keyed to the shaft 24. The'said surface has three raised portions 275. The rollers 279, 280 are carried by a pair of control rings 283, 284, arranged sideby-side. Each ring carries a pin 292, 293, one end of which engages camways 290, 291 in keys 219, 220, slidable axially in the shaft 24. Axial movement of the keys causes the rings 283, 284, to move relatively angularly thus causing the rollers of each pair to approach or separate from one another. In the first case the clutch will be disengaged, and in the second case the clutch will be engaged to transmit a bi-directional torque.' Both clutches 27, 28 are controlled by movement of a single shaft 231 having a yoke 226 engaging a key-moving collar 218 slidable axially on the shaft 24. The freewheel clutches 110, 138, Figs. 22, 23, 24, are alike, and are of the jamming roller type. Clutch 110 has three rollers 312 located between the cylindrical bore of a casing 307 and the surface of a ring 304 fixed to the shaft 25. The surface has three raised portions 310. The rollers 312 are positioned by a control ring 314 and are acted upon by springs 317 in block 316 having rollers 315 bearing on the rollers 312. A pin 318 on the ring 314 engages a cam groove 319, Fig. 25, in a key 66 slidable axially in. the shaft 25. The key is moved by a collar 206 upon rotation of a control shaft 211 whereupon the ring 314 will be turned relatively to the ring 304. Thus the clutch may be disengaged completely or be set to freewheel in one direction or other.