Patent ID: 8784161

Claim:
A double face box mandrel assembly for use on a drill pipe connection, the assembly comprising: a. a box refacing tube comprising: (i) a first end and a second end; (ii) an outer side; (iii) a shaft bore; (iv) a counter bore wherein the counter bore has a diameter at least 100 percent larger than the shaft bore; (v) a flange extending from the outer side and spaced apart from the first end and the second end; (vi) a plurality of fastening holes in the flange; (vii) a plurality of male mandrel fastening holes penetrating the second end; and (viii) an undercut formed on the outer side and adjacent the flange; b. a male mandrel adapter for engaging within the shaft bore of the box refacing tube, the male mandrel adapter comprising: (i) a shaft with a tapped hole for securing to a grinder; (ii) a mandrel flange connected to the shaft; (iii) a mandrel shaft adapter attached to the shaft; and (iv) a plurality of male mandrel adapter fastening holes; c. a fastener for connecting the male mandrel adapter to the box refacing tube; d. a box mandrel assembly slidably engaging the mandrel shaft adapter, the box mandrel assembly comprising: (i) a first bearing bore; (ii) a first retainer ring groove; (iii) a second bearing bore; (iv) a second retainer ring groove; (v) a conduit formed between the first and second bearing bores; (vi) a plurality of tightening holes connecting the box mandrel assembly to a first drill pipe connection; (vii) a first ball bearing assembly in the first bearing bore and a second ball bearing assembly in the second bearing bore; and (viii) a retainer ring for engaging the each retainer ring groove; e. a box facing mandrel adapter connected to the male mandrel adapter, the box facing mandrel adapter comprising: (i) a box facing mandrel adapter shaft for engaging with the mandrel shaft adapter through the box mandrel assembly; and (ii) a face plate flange with bolt holes, the face plate flange extending from the box facing mandrel adapter shaft; f. an outer face plate comprising: (i) a centrally formed face plate bore for mounted over the box mandrel assembly; and (ii) a plurality of face plate holes, the outer face plate for engaging the flange of the box refacing tube each face plate hole engaging a fastener; and g. an inner face plate comprising: (i) a centrally formed inner face plate bore for mounting over the box facing mandrel adapter; and (ii) a plurality of inner face plate holes, the inner face plate secured to the face plate flange with fasteners.