Vertical lift and blade control mechanism for cable plows

Abstract

A vertical lift and blade control mechanism for a plow blade which is particularly suitable for a vibratory plow assembly used for laying cable, pipe, and the like underground. The blade control mechanism is generally in the form of a parallelogram frame assembly including substantially equal length vertical frame members which are parallel and interconnected by links to form a four bar linkage arrangement that is collapsible for adjustable movement of the plow blade. The frame assembly is pivotally connected at one corner to a rigid mast assembly, and a first piston cylinder is connected between the mast assembly and frame assembly for raising and lowering the plow blade between a generally vertical plowing position and a transport position. The vertical frame members are shifted relative to each other by a second piston cylinder to provide variable digging depths for the plow blade. Thus, the plow blade may be raised, lowered or tilted by operation of the lift and blade control mechanism to adjust the digging depth and attack angle of the plow blade. Further, in a transport position, the second piston cylinder may be extended to shift the center of gravity for the plow assembly forwardly thereby providing greater stability to the assembly during transport.