Abrasive waterjet focusing tube retainer and alignment

A cutting head for a high pressure water jet cutting assembly, the cutting head comprising:

• a body including a tube portion that extends along an axis, the tube portion defining an inner chamber, a first threaded portion, and an aperture that extends through the tube portion in a direction substantially normal to the axis;
• an engagement member at least partially disposed within the aperture and movable between a first position and a second position in which a portion of the engagement member is disposed within the inner chamber;
• a focusing tube removably insertable into the inner chamber;
• and
• a retaining member having a second threaded portion that threadably engages the first threaded portion, wherein movement of the retaining member toward the body biases the engagement member into direct contact with the focusing tube to retain the focusing tube within the inner chamber and to align the focusing tube substantially along the axis.

An assembly for retaining and aligning a focusing tube, the assembly comprising:

• a shaft of a cutting head of a high pressure water jet cutting assembly, the shaft having a shaft wall defining an inner chamber open to receive the focusing tube along a longitudinal axis and an aperture formed through the wall in communication with the inner chamber, an engagement member
• having a proximal end adjacent the inner chamber upon insertion into the aperture, and a distal end, the engagement member further including
• a substantially flat face at the proximal end;
• and
• a tapered surface at the distal end;
• a retaining member couplable with the shaft, the retaining member including an internally tapered surface, wherein coupling the retaining member to the shaft engages the internally tapered surface with the tapered surface of the engagement member to advance the substantially flat face toward the focusing tube to retain the focusing tube within the inner chamber and to align the focusing tube substantially along the longitudinal axis;
• and
• a ring seated around the shaft, the ring having an inner surface, and wherein the engagement member includes a distal stepped surface engageable with the inner surface of the ring to limit movement of the engagement member.