Patent ID: 7296636

Claim:
Apparatus adapted to be attached to a motor driven vehicle for driving a post into the ground, said apparatus comprising a frame adapted to be connected to the vehicle, a generally vertical mast supported by said frame for rotation on a generally vertical axis, an elongated boom having a first portion supported by said mast for relative pivotal movement on a generally horizontal axis, a fluid actuated cylinder connecting said mast to said boom for pivoting said boom, a non-extensible connector member having an upper portion connected directly to a second portion of said boom, a fluid actuated impact driver supported directly by said non-extensible connector member in depending relation from said boom and for movement of said impact driver only with movement of said boom, said impact driver having a bottom member for engaging an upper end portion of the post, a second fluid actuated cylinder connecting said mast to said boom, and a fluid valve control system providing for raising said boom and said impact driver upwardly at one rate with limited restriction and lowering said boom and said impact driver downwardly at a controlled slower rate.