Patent ID: 9238893
Filing Date: 2016-01-19
CPC Classification: B28D,E01C,E21C,Y10T

Claim Text:
1. A combination of a cylindrical surface of a milling drum, adapted to be rotated in a cutting direction about an axis concentric to the cylindrical surface and additional apparatus, the combination comprising: a plurality of pairs of overlapping recesses in the cylindrical surface, each of the overlapping recesses extending into the milling drum a predetermined distance defined by a surrounding wall and a floor formed by the milling drum; a tooth or cutting bit having a base configuration matching a first of the pair of the overlapping recesses, and a lower portion of a side surface of the base configuration includes a retainer engagement feature, wherein the base configuration abuts and is contiguously aligned with the floor formed by the milling drum so that a cutting element positioned at an upper end of the tooth or cutting bit extends away from the cylindrical surface to form a negative rake angle with respect to the cutting direction of the milling drum, the tooth or cutting bit further comprising a conically tapered upper portion comprising a slot formed at the upper end to receive the cutting element, the slot having a slot length that is greater than a slot width, wherein the cutting element is disposed in the slot so that a portion of the upper end forms a lip extending above a bottom edge of the cutting element; a retainer having a base configuration matching a second of the pair of overlapping recesses, and a side surface including a tooth engagement feature; and a fastener securing the retainer in the second of the pair of overlapping recesses so that the tooth engagement feature of the retainer engages the retainer engagement feature of the tooth or cutting bit and fixedly retains the tooth or cutting bit in contiguous alignment with the floor.