Patent ID: 6973822

Claim:
A drop hammer apparatus comprising a drop hammer assembly, a rod partially disposed coaxially within an interior of the drop hammer assembly, and two impact zones of the drop hammer assembly and the rod on an interior of the drop hammer assembly, wherein the drop hammer assembly comprises a casing movably disposed around the rod, and first and second ends on the casing, a top plate on the first end of the casing, an end plate on the second end of the casing, wherein the rod passes through the end plate, wherein the rod further comprises upper and lower ends, and a solid steel cap on the upper end, wherein the cap on the upper end of the rod restricts movement of the end plate along the rod when the hammer is raised, and wherein the cap receives an impact of the top plate at the upper end of the rod when the hammer assembly is dropped for driving a cone of a penetrometer into ground.