Control device for earth working tool

Claim 1

In combination with a draft vehicle having transversely spaced vertically extending columns at one end thereof, a frame extending transversely of the longitudinal axis of said draft vehicle having at least one ripper tooth attached thereto, linkage means connecting said frame to said columns and power means for raising and lowering said frame on said vehicle, the improvement of said linkage means including a first pair of links each having one end pivotally attached to one of said columns adjacent the lower end thereof and the opposite end pivotally attached to the lower end of said frame, a second pair of links spaced above said first pair of links and respectively pivotally connected to the upper end of one of said columns and the upper end of said frame, with the links connected to each column disposed in a common vertical plane, said power means comprising a pair of fluid rams having relatively axially movable elements, said rams each having a longitudinal axis located in one of said vertical planes and having one of said elements pivotally supported on said frame adjacent its lower end and the other of said elements pivoted on one of said columns adjacent the upper end thereof whereby one link of each pair of said links is disposed directly above and another directly below each of said fluid rams to protect said fluid rams; said first pair of links being shorter than said second pair of links whereby said ripper tooth will be disposed in substantially vertical position relative to a ground surface when said frame is lowered into working position by extension of said fluid rams, and adapted to be swung inwardly towards said vehicle when said frame is raised into transport position by contraction of said fluid rams by means of said shorter links.