Manhole cutter

Abstract

Manhole cutter for cutting a circular groove of a fixed depth about a manhole, such as in a street, and removing the manhole from the street. The manhole cutter is suspended from a front-end loader or truck-mounted boom and rotated hydraulically from a power take-off unit on the vehicle. A cutter ring assembly with staggered cutters, and inside and outside clean-out slots rotate about a central shaft of the cutter. A manhole plate centers the manhole cutter within the manhole from the cutting operations. When the cut is of sufficient depth to extricate the manhole, a keyway disk is rotated to allow a plurality of lever grip assemblies to grip the manhole. Then, the manhole cutter and the manhole is extricated from the street, leaving a larger sized hole about the area of the manhole which is minimum in size with respect to the manhole. A plurality of staggered cutters align along the bottom of the cutter ring assembly to cut through asphalt and dirt, and are mounted in the cutter ring assembly by a bolt and rectangular bar.

Dependencies are inferred from the claim text.