Post driving machine

Abstract

An improved portable hydraulically powered driving machine, for driving posts, ground anchors, concrete breakers, core drills, and the like work pieces into the ground, pavements or wall structure, has a tower in the form of a stanchion carried by an extensible pedestal mounted boom rig on a mobile base such as a conventional truck and in its working position is adapted to rest on the ground, pavement or wall structure at a controlled attitude relative thereto to guide a hydraulically powered hammer and hold an anvil against the work piece and, in its transporting position is adapted to be secured horizontally at a low level in a truck-mounted frame. The stanchion down-crowds the hammer guide to load a compression spring which maintains the anvil continuously against the work piece even after the impact force of the hammer blow is expended and the work piece advances a considerable distance. The hammer is also spring-loaded, a hydraulic jack lifts the hammer and stretches the spring and the stroke of the hammer together with the rapidity of the hammer blows is controlled by a rotating dump valve for the jack. The speed of rotation of the dump valve is controlled by the machine operator with faster speeds decreasing the stroke of the hammer and increasing the number of blows delivered per minute. Hydraulic controls are provided to accurately place the stanchion at the work site and to control the angle and direction in which the hammer blows are to be delivered. Air is introduced into the fluid return line from the dump valve for cushioning fluid flow.