Patent ID: 7703856

Claim:
An apparatus for freeing an angular manhole cover frame having a vertical axis of alignment embedded in pavement from said pavement comprising: a ring-shaped base with at least one circular track defined thereon about its entire circumference; a plurality of releaseable anchoring fasteners located at intervals about the circumference of said base and which immobilize said base relative to said manhole cover frame so that said base is supported atop said manhole cover frame in coaxial alignment therewith; a saw mounting framework disposed atop said ring-shaped base and having a plurality of track followers that engage said track, whereby said saw mounting framework is movable in rotation about said vertical axis of alignment of said manhole cover frame; a saw mounting arm joined to said saw mounting framework by a saw arm orientation hinge having a horizontal saw arm hinge axis; a saw arm locking mechanism for locking said saw mounting arm relative to said saw mounting framework in a vertical orientation relative thereto; a saw carriage mounted on said saw arm for reciprocal movement toward and away from said saw arm hinge axis; a saw motor having a saw motor housing and a saw blade rotor mounted for rotation about a saw rotor axis relative to said saw motor housing; a releaseable saw motor lock for immobilizing said saw motor housing relative to said saw carriage at alternative selected angles of orientation of said saw rotor axis relative to said saw mounting arm; and separate horizontal-cut and vertical-cut saw blades alternatively and interchangeably attached to said saw blade rotor.