Rollover apparatus for plows

A rollover apparatus for a two-way plow having a supporting mobile framework and a plow frame pivotally mounted to the mobile framework about the center axis of a pivot shaft, comprising:

• a rigid crank arm operatively fixed to the plow frame and extending radially outward from the center axis of the pivot shaft for joint coaxial movement with the pivot shaft;
• an elongated rigid lever arm pivotally connected at one end to the crank arm about a first axis parallel to and spaced from the center axis of the pivot shaft, said lever arm having an arcuate side edge facing toward said pivot shaft and enabling the lever arm to wrap about the pivot shaft as the shaft is turned about its center axis through an angular distance of at least 180.degree. degrees;
• said elongated lever arm extending angular outward from the crank arm to one side of said center axis;
• an intermediate rigid link having a first end pivotally connected to said framework about a second axis parallel to and spaced to one side of the center axis of the pivot shaft, the remaining end of said link being pivotally connected to said lever arm about a third axis parallel to said center axis of the pivot shaft;
• a hydraulic cylinder having an extensible piston rod movably mounted therein;
• said hydraulic cylinder being pivotally mounted to said framework about a fourth axis parallel to said center axis of the pivot shaft;
• the outer end of said piston rod being pivotally mounted to said lever arm about a fifth axis spaced outwardly along the length of said lever arm from said third axis and parallel thereto, whereby pivotal forces are transmitted from the framework to the crank arm directly through the pivotal connections between the piston rod of the hydraulic cylinder and the lever arm.