| 摘要 |
1,139,359. Vehicle seats. R. WIENERS. 13 Nov., 1967 [26 Nov., 1966], No. 51572/67. Heading A4U. The initial tension of the springs of a tractor seat is automatically adjusted by the weight of the driver. A seat cradle 1 is movably connected through guide arms 4, 5 to a support frame 6 and the pivots of the lower guide arms 4 are provided with torsion springs 8, 9. The torsion springs 9 have a common shaft on to which a lever 22 is fixed, and the lever 22 lies against the short arm 25 of a two armed lever 24, 25 the longer arm 24 of which has a forked end engaging a nut 26 on the threaded part of a spindle 20 freely rotatable but not axially displaceable on the support frame 6. Two pressure members 28, 29 are pivoted on pins 30 on one of the guide arms 5 and have bars 33, 34 which are pressed by a rubber band 35 or a traction spring against a roller 36 pivotally mounted on the support frame. If the tractors is being driven by a light driver the seat will move upwardly initially to cause a rubber block 31 on the upper pressure member 28 to be pressed against the periphery of a cylinder 27 on the spindle 20 and so rotate the spindle clockwise. The nut 26 therefore moves to the left and is followed by the lever 24, 25 and the initial tension of the torsion springs is reduced. When the seat moves in the return direction the block 31 is withdrawn from the cylinder 27. If a driver of greater weight now drives the vehicle the seat is deflected downwardly too far and a second rubber block 32 on the lower pressure member 29 comes into operation to rotate the cylinder 27 in the opposite direction thus increasing the tension of the torsion springs 9. One arm of the lever 24, 25 serves as an indicator and a scale is provided on the support frame. The rubber blocks 31, 32 and cylinder 27 can be replaced by pawls and a disc with two oppositely directed serrations. A shock absorber is provided between the seat and the support frame. |
