Reamer assembly

1. An adapter for connecting drilling components, the adapter comprising:

an elongate tubular member having a non-circular exterior surface profile and a connector;

a ground engaging member comprising a non-circular inner surface profile thereof whereby the ground engaging member is slidably mounted on the non-circular exterior surface of the tubular member, when such profiles are brought into alignment by rotation of one member relative to the other, in a manner effective to pass torque from one member to the other by means of the non-circular profiles;

a shaft disposed within the ground engaging member and comprising a first end and a second end, the first end comprising a second connector for mating engagement with the connector of the elongate tubular member, the second end comprising a threaded connector; and

a flange assembly comprising a flange housing and a flange, wherein the flange is connected to both the second end of the shaft and the ground engaging member to restrict axial movement of the ground engaging member relative to the tubular member;

wherein the non-circular exterior surface of the first member and the flange housing are all supported within the ground engaging member.

2. The adapter of claim 1 further comprising holes in the ground engaging member for receiving a fastener to secure the flange assembly to the ground engaging member.

3. The adapter of claim 1 wherein the flange assembly comprises:

a bearing assembly supported within the flange housing; and

a product pipe lug supported within the flange housing by the bearing assembly and extending from a downhole end of the ground engaging member.

4. The adapter of claim 1 wherein the reamer flange comprises a plurality of bayonet notches and fastener holes and wherein the flange of the flange assembly comprises a plurality of bayonet tabs configured fit within the bayonet notches.