Abstract: An excavating machine has a plurality of tooth receiving support blocks mounted for movement thereon to enable an excavating operation to be carried out when digging teeth are mounted to the blocks. Each support block has a cylindrical bore for receiving the cylindrical shank of a prior art rotatable type bit. The present improvements provide the combination of said support block with a non-rotatable dirt type excavating tooth. The tooth includes a cylindrical shank at one end thereof made complementary respective to the block bore so that the shank can be telescopingly received in a captured manner within the bore of the support block, thereby mounting the excavating tooth to a block. A stop means is formed on said block for engaging an abutment means of the tooth and prevents axial rotation of the tooth when the shank is received within the bore.

Abstract: A digging tooth is removably received within a tooth receiving holder. The holder is attached to a digging apparatus, such as a trencher machine, for example. The holder includes a socket within which a shank of the tooth is removably received. The socket of the holder is in the form of an outwardly opening, elongated cavity which rearwardly tapers so that the cavity is progressively reduced in size. The tooth shank is rearwardly tapered and made complementary respective to the socket cavity, so that when the shank is telescopingly forced into the cavity, it is wedgedly held in assembled relationship and is easily removed therefrom, and the teeth therefore can subsequently be rapidly and easily replaced.