GB1202412A - Improvements in or relating to vehicles provided with power take-off shafts - Google Patents

Abstract

1,202,412. Tractor power take-offs. C. VAN DER LELY N.V. 24 Aug., 1967 [29 Sept., 1966], No. 39089/67. Heading B7H. [Also in Division F2] A vehicle is provided with a power take-off shaft 28 driven through an hydraulically actuated friction clutch 13, a mechanical coupling, which is engageable and disengageable by means of an hydraulically operated adjusting mechanism, disposed between the clutch 13 and the power take-off shaft, the clutch 13 and the mechanical coupling being engaged and disengaged by the same control lever 2 by means of which the flow of fluid both to and from the clutch and the adjusting mechanism is controlled. On movement of the lever 2 to the left in the direction of the arrow A from the neutral position shown in which the hydraulic lines 3, 4 are connected through the control unit 1 to a fluid reservoir, pressure fluid from a supply line 91 is supplied through a line 4 and hence, directly and through a non-return valve 6, to both sides of a piston 8, thereby moving the piston to the left to engage a toothed clutch 16, which is rotatable with a shaft 15, with a gear 20 to drive the shaft 28 through reduction gearing 20, 23 and 24, 21 and through a line 11 and an adjustable restrictor 12 to engage the clutch 13 after the engagement of the mechanical coupling to drive the shaft 15. On movement of the lever 2 in the opposite direction, pressure fluid is supplied to the line 3 only and hence to the left-hand side of the piston 8, thereby engaging the coupling 17 with the gear 21 to rotate the shafts 19 and 22 together. Fluid is also supplied through the line 11 and restrictor 12 to engage the clutch 13. In modifications, an hydraulic accumulator is provided between the restrictor 12 and the clutch 13 (Figs. 3, not shown) and the two-speed mechanical coupling is replaced by a dog clutch (Fig. 4, not shown) and the control unit may be replaced by a four-way or three-way valve.