Hydraulic actuated moldboard with automatic lock

Apparatus for automatically positioning and locking a moldboard unit in regard to a prime mover that includes

• a moldboard unit movably attached to a prime mover by a vertical pivot whereby the unit may be angularly positioned about the pivot,
• sector means secured to the moldboard unit for movement through an indexing station, said sector means having a series of openings circumferentially spaced about the center of the pivot,
• a fluid actuated drive means for angularly positioning the moldboard unit,
• fluid control means for selectively connecting the drive means to a pump to angularly position the moldboard unit to align one of said openings in the sector means within the indexing station, and to a fluid reservior to relieve the fluid pressure on the drive means,
• locking means in the indexing station having a reciprocating locking bar that responds to the control means to automatically insert the bar in an opening aligned within the indexing station when the drive means is connected to the fluid reservoir and to withdraw the bar from the opening when the drive means is connected to the pump.

Snowplowing apparatus that includes a support unit mounted upon the front of a motor vehicle having a vertically disposed pivot at the front of said support unit, a sector frame mounted upon the pivot for rotation in a horizontal plane, a moldboard unit secured to the front of the sector frame for movement therewith, said sector frame further including a plurality of lugs circumferentially spaced along a radius disposed rearwardly from said pivot to establish openings between said lugs, a hydraulic reversing cylinder secured to said support unit and having an extendable rod connected to the sector frame for angularly positioning the moldboard in said horizontal plane, a hydraulic locking cylinder secured to the support unit having an extendable locking bar that is movable between a first locking position wherein the bar is positioned in an opening between said lugs to prevent movement of said moldboard and a release position outside said opening wherein the moldboard unit can turn about said pivot, a control valve that is selectively positionable to admit fluid under pressure to said reversing cylinder to move the moldboard unit in either direction about said pivot to a desired plowing position and to relieve the fluid pressure on said cylinder when the moldboard unit is at rest in a desired position, a shuttle valve coupled to the control valve for diverting a portion of the high pressure fluid admitted to the reversing cylinder to the locking cylinder to move the locking bar into a release position anytime the moldboard unit is being rotated by said reversing cylinder, and a biasing means acting on the locking bar to drive the bar into a locking position when the pressure on the locking cylinder is relieved.