| 摘要 |
1,142,114. Change-speed control. GEBR. EICHER, TRAKTOREN - U. LANDMASCHINENWERKE. 28 April, 1967 [4 Nov., 1966], No. 19671/67. Heading F2D. The ratio of an infinitely variable hydrostatic gear for a vehicle such as an agricultural tractor is set to a desired value by a hand lever 3 and can be varied or reversed by operation of a pedal 17, the ratio returning to the desired value on release of the pedal. The hand lever 3 is linked to a bell-crank lever 7 which is linked to a lever 10 fast with a shaft 11 having a lever 12 connected by a rod 13 to a lever 15 which is pivoted at its midpoint 16 to a lever 18 and is pivoted at 20 to a rod 21 which is connected to a lever 23 adjusting the transmission. The lever 18 is fast with the pedal 17 and is pivoted at 19 to a fixed part, and the pivot point 16 bears against a rubber buffer 26. On movement of the hand lever 3 from the position I, in which the vehicle is stationary to a position II, the resistance to movement of the adjustment device operated by lever 23 holds the pivot 20 stationary and the pivot 16 moves, compressing the rubber buffer 26. On further movement of the lever 3 towards a position III the pivot 16 does not move further and the pivot 20 is shifted to the right, thus moving the lever 23 and operating the adjustment device to give forward movement, the position of the lever determining the ratio, and the lever 3 being retained in its set position by friction discs. If the speed is to be increased above that set by the lever 3, pedal 17 is pivoted in the direction of arrow A. The resistance provided by the friction discs acting on the lever 3 is greater than that of the adjustment device, so that the end 14 of the lever 15 is held stationary and the lever is pivoted anti-clockwise about this end to adjust the ratio. On release of the pedal a restoring device (see below) returns the lever 23 and pedal 17 to their original positions. If the ratio is to be reduced or the vehicle reversed, the pedal 17 is pivoted in the direction of arrow B, the maximum reverse position of the linkage being shown in chain-dotted lines. The adjusting lever 23 is fast with a shaft 24 which is fast with a plate 27 (see Fig. 4) having a cam slot 28 co-operating with a guide pin 29 on a lever 38 which is pivoted at 39 and actuates the adjustment device. The guide pin 29 is also connected to a rod 31 connected by a centring spring 34 to a housing 35 to provide the restoring force for returning the adjustment device to its preset position on release of the pedal 17. The housing 35 can be given a slight pivotal movement by an eccentric adjusting means in order to enable the speed to be set accurately to a low value to provide a constant crawling speed. The lever 23 is also connected to the speed control member of the driving engine, such as the regulator rod of a diesel engine, so that when the selector lever adjusts the ratio to give increased speed the fuel supply to the engine is increased correspondingly. |
