| 摘要 |
<p>1,219,548. Hydrostatic transmission control. EATON YALE & TOWNE Inc. 8 April, 1969 [8 April, 1968], No. 17944/69. Heading F2D. In a control system for a vehicle hydrostatic transmission 11 wherein a manual control element is connected by a linkage to a lever 41 controlling the ratio of the hydrostatic transmission 11, the linkage contains a lost-motion connection which permits a spring assembly 120 to move the lever 41 to its neutral position when the manual control element is within a predetermined distance of its neutral position. A manual control lever 12 is connected through a linkage 30 ... 34 to a lever 35 fast with a stubshaft 36 and two pedals 13, 14 are also connected to the lever 35 through linkages 70, 80 so that rotation of the lever 12 from its neutral position 20c or depression of the pedal 13 or 14 rotates the lever 35 and stub shaft 36 in one direction or the other. The stub shaft 36 carries a lever 37 connected through a lost-motion spring coupling 40 to the lever 41 so that rotation of the stub-shaft 36 pivots the lever 41 to operate a control valve 43 which supplies pressure fluid to a follow-up servomotor 46 controlling the swash-plate of the hydrostatic transmission 11. The lost-motion in the linkage may be provided by a lost-motion connection between a rod 39 and the lever 41 or may be provided in the lost-motion spring connection 40. The spring assembly 120 is adjustably secured to the tractor by an eccentric mounting (Fig. 9, not shown). Adjustably positioned spring-pressed plungers (60), Figs. 2-4 (not shown), project into the path of the lever 12 to indicate to the driver that a predetermined ratio has been obtained. Additional effort is required to move the lever 12 past the plungers (60). A lost-motion spring coupling 33 in the linkage 30 . . . 34 between the lever 12 and lever 35 permit the latter to be rotated by the pedals 13, 14 without a corresponding movement of the lever 12. The pedals 13, 14 carry lugs 73, 83 engageable with arms 72, 82 fast with a sleeve 74 and shaft 75 carrying arms 78, 85 connected by links 79, 86 to the lever 35. On depression of one of the pedals, e.g. 13, the lug 73 engages the arm 72 and acts through the linkage to rotate the lever 35 anticlockwise. The rotation of the lever 35 acts through the linkage 86, 85, 75 to rotate the arm 82 clockwise. Sufficient clearance between the lugs 73, 83 and the arms 72, 82 is provided to prevent clockwise rotation of the arms 72, 82 effecting movement of the pedals 13, 14.</p> |
