Sowing machine, in particular for corn or beet seeds

Claim 1

A sowing machine comprising a chassis, at least one first support wheel carried by the chassis at the rear of the chassis, a seed distributor carried by the chassis, a support for fixing to the rear of a tractor, a connecting device for interconnecting the chassis and support and comprising a lower link and an upper arm which have first end portions pivoted to the chassis by two spaced apart pivots and second end portions pivoted to the support by two spaced apart pivots, the chassis having a front end part, at least one auxiliary support wheel, means for detachably mounting the auxiliary support wheel on said front end part, the upper arm of the connecting device comprising two elements which are relatively slidably interengaged, releasable means for interlocking the two interengaged elements so as to constitute an upper link of fixed length which forms, together with the lower link and said four pivots on the chassis and support, an articulated parallelogram system, said releasable means being capable of allowing said interengaged elements to slide with respect to each other and rendering the upper arm completely inoperative when the releasable means are released so that the chassis is no longer constrained to maintain a constant angle relative to said support and the auxiliary wheel, when mounted in said front part of the chassis, constantly bears on the ground and determines, in cooperation with said first support wheel, the angle of the chassis relative to the ground, the connection between said chassis and said support as concerns the drawing of said chassis by said support being ensured exclusively by said lower link.