Patent GB-1494895-A (GB)
Title: Epicyclic change speed gears
IPC: B62M11/16
Filed: 1973-12-15
Abstract: 1494895 Change speed gear RALEIGH INDUSTRIES Ltd 6 Dec 1974 [15 Dec 1973] 58416/73 Heading F3D A pedal-cycle hub-gear selects seven ratios, four reduced, direct drive and two overdrives, by turning a cam selector 22 (Fig. 5) controlling one-way clutches P1 ... P6, connected to elements of first and second sun-ring-planet trains 11, 12, both having permanently fixed suns splined to the spindle 13, the clutches selectively connecting either ring or either carrier to output; first ring or first carrier to input; first ring to second ring; and first carrier to second carrier. The cam selector 22 may be turned by a pulley 22b and spring-loaded single cable, or by an arrangement internal to the fixed spindle 13. Drive from the input sprocket 26 and member 14 enters the gear through a selected one of two, P5, P6, of the one-way clutches, and issues to the output hub shell 16 through a selected one of two, P1, P2, of the one-way clutches, the remaining two, P3, P4, respectively connecting together the two ring gears and the two planet carriers. The one-way clutches are selectively disabled by raising tails, e.g. 17a<SP>1</SP> on their pawls 17, by selective axial movement of three pawl actuators 33, 34, 35, having cam follower portions 30, 31, 32, Fig. 5, following cam profiles 27, 28, 29 on the cam sleeve 22. The actuator 33 actuates the pawls 17a, 18a through a sleeve 33b having three axially-spaced pawllift ribs 36, 37, 38, and abutting a shoulder 33a<SP>1</SP> on the actuator 33. The actuator 34 actuates the pawls 20a, 21a directly by a step 34a, whilst actuator 35 actuates the pawls 19a through a chamfered disc 35b. Springs 39, 42, 44 load the actuators on to the cam profiles, and a clock spring 22d, or external spring, torsionally loads the cable-pulley 22b. Co-operating projections on the pawl-lift sleeve 33b<SP>1</SP> and slots 14a<SP>11</SP> on the input member 14 ensure their co-rotation, and rotation of the pawl actuators 33 ... 35 is prevented by the actuators 35 passing through slots in the fixed sun 11d and through cooperating splines 40, 43. The ratios are as follows.  First.-Through P6 to first ring, first train 11 and carrier, P4, second train carrier and P1 to output. First train 11 acts alone in reduction. Second.-Through P6 to first ring, P3, second ring, second train 12 and carrier, and P1 to output. Second train 12 acts alone in reduction. Third.-Through P6 to first ring, first train 11 and carrier and through P4 to second carrier, through the second train and ring and P2 to output. Trains in series, first, 11, reducing, second, 12, overdriving. Fourth.-Through P6 to first ring, P3, second ring and P2 to output. Direct drive. Fifth.-Through P5 to first carrier, first train and ring, P3, second ring, second train and second carrier and P2 to output. Trains in series, first, 11, in overdrive, second, 12, reducing. Sixth.-Through P5, first carrier, P4, second carrier, second train 12 and ring, and P2 to output. Second train 12 acting alone in overdrive. Seventh.-Through P5 to first carrier, first train 11 and ring, P3, second ring, and P2 to output. First train 11 acts alone in overdrive.