| 摘要 |
1,229,365. Hydrostatic transmission control. FMC CORP. 19 Nov., 1969 [21 Nov., 1968], No. 56604/69. Heading F2D. Control of the pump in a tractor hydrostatic tranmission 48, e.g. comprising a variable displacement pump and a fixed displacement motor, is effected by turning a shaft 54 in opposite directions for forward and reverse, the shaft being turned by a foot pedal (24), Fig. 1 (not shown), acting through linkage 58 carrying a pin 108 connected to a lever 110 fast with the shaft, a pair of arms 118, 120 being freely mounted on the shaft and being interconnected by a tension spring 122 to urge them against a stop 74 and the pin 108 to return the shaft 54 to its central neutral position on releasing the pedal (24). The lever 110 carries a contact 133 of a switch SW2 to prevent starting of the tractor engine unless the transmission is in neutral. A second switch (SW1) in series with the switch SW2 prevents starting also unless a power takeoff (18) driven through V-belts (26) from the engine, is manually disengaged by moving the belt tensioning roller (32). A park lock 94 is manually engageable with a transmission output pinion 60 through an over-centre spring toggle arrangement 86-96 actuated by a shaft 80 when the transmission is in neutral. The shaft 80 also turns a lock hook 76 pivoted at 72 and having a slot 106 to receive the pin 108 when the transmission is in neutral so that the park brake may only be applied when the transmission is in neutral, and the transmission is then maintained in neutral until the park brake is disengaged. The wide mouth 132 of the slot 106 limits the possible pump displacement in forward and reverse. |
