Disk opener carrier hitch

A hitching apparatus for an agricultural implement, wherein:

• the apparatus includes an elongate hitch member;
• the apparatus includes a pitch-mode pivot connection A between the hitch member and an implement member;
• the pivot connection A is such that, in operation of the apparatus, the implement can pitch-pivot relative to the hitch member about the pivot connection A, whereby, during pivoting, the distance L from a point C on one of the members to a point D on the other of the members, being points spaced from pivot A, varies in length;
• when the tractor and the hitched trailer are on flat level ground, the distance between points C and D is L0;
• the apparatus includes a first mechanical link, which is operative between point C and point D;
• the first mechanical link includes a hydraulic ram, and the link is variable in length as the ram is operatively extended and retracted;
• the first mechanical link includes a fixed-connection means at one end of the link, at which the link is pivotally fixed to point C, and includes a floating-connection means at the other end E of the link;
• the structure of the first mechanical link and of the floating connection means is such that the said other end E of the link is movable into a transport-position, in which the ram is extended and the link makes forceful abutment with point D, and into a working-position, in which the ram is retracted and the end E of the link is clear of abutment with point D;
• the floating connection means includes a floating guide link, for guiding and constraining the end E of the first mechanical link into and out of abutment with the point D;
• a point on the floating guide link is pivotally fixed to a point F on the said other member, being the member on which lies point D;
• a second point on the floating guide link is pivotally fixed to a point G on the first mechanical link;
• the arrangement of the floating link is such that the point G on the floating link moves in an arc about the point F when the ram is extended and retracted, an F-G radius of the link being the radius between point F and point G;
• the geometrical arrangement of the floating link, and of its arc of movement, is such that, when the ram is extended so far that the end E of the mechanical link makes forceful abutment with the point D, the F-G radius of the floating link lies substantially perpendicular with respect to the axis of the ram;
• the apparatus includes a ram travel-limit-means;
• the ram is extendable in length, upon being supplied with hydraulic pressure, up to a limit of extension;
• the limit of extension is defined by the ram travel-limit-means;
• the ram is of such dimensions that, at its limit of extension, the distance between points C and D is greater than L0.