| 摘要 |
<p>1509448 Rotary harrows C VAN DER LELY NV 31 July 1975 [6 Aug 1974] 32135/75 Heading A1B Rotary soil-working members 16 are mounted on two frame portions 13 separately movable up and down relative to the wheeled main frame 1, a separate gear box 30 being mounted on each frame portion 13 to transmit drive to the soil-working members 16. Telescopic shafts and universal joints couple the tractor p.t.o. shaft to a central gear box 37 similarly coupled to the gear boxes 30 through which pinions 29 of the members 16 are driven. For inoperative transport of the harrow, the frame portions 13 are raised by hydraulic cylinder assemblies 23 acting on pivoted parallel linkages 14 between the beam 2 of frame 1 and frame portions 13, and a transport drawbar 58 at one end of frame 1 is pivoted about pins 52 into a position for connection to a tractor whilst working drawbar 51 is pivoted into a position on top of the harrow. Ground wheels 8 are castor wheels but can be locked in a working or transport position by pins 9. Each frame portion 13 has a roller 20 pivotally mounted thereto and an adjusting member 22 varies the height of the rollers 20 with respect to members 16 and hence the soil-working depth. A tool bar 27, supported by arms 26 pivotally attached to frame 1, carries tools such as seed drills 28. Chains connected between frame 1 and frame portions 13 limit downward movement of the latter. Reference has been directed by the comptroller to Specification 1433491.</p> |
