Abstract: A ploughshare assembly includes a ploughshare and a support for the ploughshare. A pair of opposed internal edges defines a recess in the ploughshare. A holder formation on the support includes a foot portion and a pair of grooves adjacent the foot to receive the aforesaid internal edges of the ploughshare so that when the ploughshare is in its working position on the support the foot engages underside the ploughshare and retains it in place. An aperture in the ploughshare behind the internal edges is wider than the separation of the edges and is dimensioned to pass the foot when the ploughshare is sufficiently rotated relative to the support and so allows detachment of the ploughshare from the support. A resilient latch detachably mounted to the support is releasably positionable to engage a detent face on the ploughshare to prevent excessive forward movement of the ploughshare with respect to the support.

Abstract: An agricultural implement such as a cultivator includes a support body and a ground treatment tool depending from the support body for pivotal movement forwardly to and rearwardly from a work position.Means is connected to the support body for biasing the tool to its work position. This biasing means and the ground treatment tool are pivotally coupled at spaced locations to a lever which slidably rests between such locations on a roller providing a fulcrum for the lever. As the tool retracts in response to a pre-determined resistance to its forward movement through or along the ground, it pulls the lever across and about the roller against the biasing means, resulting in relative movement of the fulcrum along the lever and consequent variation in the effective biasing force on the tool.

Abstract: Apparatus for feeding granular material into a gas stream, for example seed or fertilizer into multiple airstreams of an agricultural vehicle, includes a receptacle for granular material, a duct for a gas stream, and a pair of resiliently compressible surfaces which contact or almost contact to define a nip between them. The surfaces may be provided by contrarotatable rollers and are disposed so that granular material may pass from one side of the nip through a port into the duct, and are moveable into the nip from the other side. The apparatus further includes metering means defining a controllable outlet from the receptacle and positioned with respect to the nip for feeding granular material into the nip from said other side at an adjustable controlled rate. Also disclosed is a distributor for gas-entrained granular material which includes a conical, part-conical or inverted conical surface in a diverging housing.