| 摘要 |
<p>857,008. Change-speed control. ZAVODY 9. KVETNA NARODNI PODNIK. April 30, 1958 [May 3, 1957], No. 13747/58. Class 80 (2). [Also in Group XXXI] A gear-changing mechanism, for a motor cycle or scooter having a gear-box providing four forward speeds, comprises a twist grip 36 for preselecting a gear and a lever 40 for disengaging the main driving clutch and establishing the gear ratio. Grip 36 is operatively connected to a plate 10 pivoted at 11 and having cam slots engaging pins 8, 9 of sleeves 6, 7 which are loosely mounted on a gear change shaft 1. Pins 8, 9 also co-operate with slots in a stationary plate 12. Sleeves 6, 7 are disposed within forked mountings of selector members 3, 4 having suitably shaped slots 16, 17 co-operating with shift forks 18, 19 of the gear change mechanism. Lever 40 is either mounted on the twist grip and rotatable therewith, or is mounted on the handle-bar, and is connected by a cable 39 to a bell-crank lever 38 having an arm 42 formed with a cam surface actuating a follower 43 for disengaging the clutch. Bell-crank 38 also has a lost-motion connection with the shaft 1 such with on actuating lever 40 the clutch is disengaged before the lost-motion is taken up and shaft 1 rotated. The shift forks have sleeves 20, 21 provided with pins 29, 30 co-operating with circumferential grooves 22-27 and a longitudinal groove 28 in the shaft 1. In operation, twist grip 36 is rotated to an appropriate position to preselect a gear, thereby rotating the cam plate 10 and through pins 8, 9 and sleeves 6, 7 moving the selector members 3, 4 axially of shaft 1. When lever 40 is actuated, the clutch is disengaged and shaft 1 rotated to bring groove 28 into register with pins 29, 30. Rotation of shaft 1 also, by means of keys 5, results in the rotation of the selector members 3, 4. During this rotation the shift forks are shifted axially of the shaft 1 by the edges of the slots 16, 17 as the ends 16a, 17a of the slots are moved towards the forks, groove 28 being of sufficient width to permit this. The appropriate gear is thus engaged. When lever 40 is released the bell-crank lever is returned to its initial position by a spring 31 so that the clutch is engaged, groove 28 is moved out of register with pins 29, 30 so that the shift forks are retained in position axially of the shaft 1 by the appropriate circumferential grooves, and the selector members are rotated to their initial position in which the shift forks are located in wide parts of the slots 16, 17.</p> |
