Method and apparatus for removing trip hazards in concrete sidewalks

A cutting apparatus mountable on the spindle of a rotatable threaded output spindle of a right-angle grinder motor, said cutting apparatus comprising:

• a hub having an axis of rotation and an attachment collar with a central mounting aperture coincident with said axis, said aperture being threaded to spirally engage the output spindle, said collar having at least one pair of flattened parallel sides sized to receive a wrench, with which said hub may be tightened onto said threaded output spindle;
• a generally circular blade having an axis of rotation, a metal matrix edge in which diamond grit is embedded, an upper major surface which mates to said hub, said blade also having a plurality of countersunk attachment holes perpendicular to said axis of rotation;
• and
• a nut and a blade attachment screw having a countersinking head for each attachment hole, said blade attachment screws and associated nuts being threadably engagable to secure said blade to said hub such that the head of each screw is flush with a lower surface of said blade.

A cutting apparatus mountable on the spindle of a rotatable threaded output spindle of a right-angle grinder motor, said cutting apparatus comprising:

• a hub having an axis of rotation and a central mounting aperture coincident with said axis, said aperture sized to fit over the output spindle, said hub having a lower blade backing surface;
• a generally circular blade having an axis of rotation, a generally circular laminar metal core formed so as to have a center portion with a raised upper surface and an indented lower surface, said core having a planar flange portion extending radially from the center portion, said flange portion having an outer circular circumferential edge, said blade having a metal matrix edge affixed to the circumferential edge of the flange portion, said metal matrix edge being embedded with diamond grit, said center portion having a central mounting hole sized to fit over the output spindle, at least a portion of said raised upper surface mating with the lower blade backing surface of said hub;
• and
• a nut having a top edge extension is swedged within the central mounting hole, said nut sized to spirally engage the threads of the output spindle, and thereby secure the blade and the hub to the output spindle.