| 摘要 |
<p>896,995. Change-speed control. ZAVODY 9., KVETNA, NARODNI PODNIK. Sept. 19, 1958 [March 25, 1958], No. 30041/58. Addition to 863,325. Class 80 (2). A change-speed control for a single-track vehicle of the type described in the parent Specification wherein operation of an executive lever 30 in the appropriate direction establishes the next succeeding ratio up or down, or alternatively any other pre-selected ratio, comprises shift-forks 18, 19 shifted axially by turning shift cams 2, 3 splined on a shaft 1, along which the shift cams are moved to selected axial positions by turning a cam selector-drum 9 formed as a part-cylinder rotatable on the shaft 1 and having cam slots engaging pins 6 on sleeves 5 freely mounted on the shaft 1 between end flanges of the shift cams, and prevented from rotation by a guide-slot 14. For pre-selective operation, a control, not shown, operates through a bell-crank 29, to shift upwards a shaft 25 splined to the executive lever 30, causing a tongue 24 on the shaft 25 to make a torsionally rigid connection with a slot 22 in the shaft 1, whereupon actuation of the executive lever in either direction turns the shaft 1 and shift cams 2, 3 directly to establish a shift which has been pro-selected by a control which turns the selector drum 9 through a cable 16. After the shift the lever 30, shaft and shift cams are returned by springs (not shown) to the initial position. For operation by establishment of the next succeeding ratio up or down without preselection, the control is operated at 29 to move the shaft 25 downwards, which causes its tongue 24 to engage with lost-motion a slot 23, Fig. 5, in the shaft 1 and also couples the shaft 25 by dogs 34 to a pawl carrier 31. Subsequent operation of the executive lever 30 in one or other direction first turns the pawl carrier 31 causing one or other of two oppositely-acting pawls 32, 33 to pass through a corresponding window 36 in a fixed mask 35 and step a ratchet segment 38 fast to the selector drum 9 through one step in the appropriate direction. Further movement of the executive lever 30 takes up the lost motion 23 and turns the shaft 1 and with it the shift cams 2, 3 for introducing the next succeeding ratio, after which the lever springs back to its initial position. The pawls during the further movement ride on to and slide over the mask 35. The movement of the selector drum 9 also actuates the preselector control 16 which indicates the ratio selected.</p> |
