| 摘要 |
It consists in connecting the rocker 1 for transmission of movement to the output shaft 20 with the planar cams 8 and 9 via rollers 6 and 7 mounted on lateral lugs 3 and 4 of the aforesaid rocker 1, said rollers being slightly offset in terms of height, so that, whilst one of them rests on the outer surface 11 of the channel 10 of a planar cam, the other rests on the inner face 12 of the aforesaid channel 10 of the relevant cam. A similar vertical offset exists between the rollers 16-17 which connect the rocker 1 to the shaft 20 and the upper 21 and lower 22 faces of the bush 19 via which the shaft 20 of the rocker 1 receives the movement, there also being a fixed stop 23 for the rollers 24 which act on the spherical-profile cam 5 and the shaft 20 incorporating, at an upper level, two toothed discs 25 and 26, one associated with the shaft 20 and the other with the support thereof, which define an engagement (clutch) which blocks the shaft 20 in a rotary direction when the latter adopts a lower limit position, in which position an optional disengagement (clutch throwout) is nevertheless feasible by means of axial displacement of the shaft 20 against frustoconical springs 30. <IMAGE>
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