Device for grafting grapevines

A device for grafting plant shoots, especiallly grapevines, by cutting and joining the extremities of scion and stock in a contoured joint in which the scion is held by the stock both longitudinally and in axial alignment, the device comprising in combination:

• a stationary base plate having arranged thereon shoot positioning means defining a generally horizontal transverse shoot axis;
• a vertically movable cutter blade of thin stock defining a generally vertical plane at right angles to the shoot axis and having a cross-sectional shape which produces a transverse cut on the shoots with a central bulge resembling the shape the Greek letter omega, so that cut extremities have matching tooth and tooth gap shapes, the cutter blade having a corresponding vertical fold profile defining a bead on one side and a groove on the other side thereof;
• means for moving the cutter blade in a generally vertical reciprocating motion, so as to cause the cutter blade to sever a first shoot which is positioned underneath it, in the shoot axis of the shoot positioning means;
• means for retaining the cut extremity of the first shoot on the upwardly moving cutter blade, while the cutter blade severs a second, oppositely extending shoot which has subsequently been positoned underneath it, in the shoot axis;
• and
• means for releasing the first shoot from the cutter blade simultaneously with the second shoot, while joining the extremities of both on their shaped cuts, said releasing means including:
• an upwardly movable ejector member arranged laterally adjacent to the fold profile of the cutter blade above the shoot axis;
• a stationary stripper bracket arranged adjacent to the fold profile of the cutter blade, on the opposite side of the ejector member, so as to remove from the cutter blade any clipping or shoot that may be carried upwardly by the fold profile of the blade by blocking the upward movement of the clipping or shoot;
• latching means for selectively blocking the upward mobility of the ejector member by engaging the latter at a level at which the blocked ejector member forcibly removes the previously retained first shoot from the upwardly moving cutter blade by blocking the upward movement of the former;
• toggle means for alternatingly engaging the latching means against the ejector member, when the cutter blade performs a cut on the second shoot, and not engaging the latching means against the ejector member, when the cutter blade performs a cut on the first shoot.