| United States Patent | 6,437,285 |
| Thomas , et al. | August 20, 2002 |
A method and system for treating internal surface material overlying the interior of a tubular a substrate, and more particularly, to a system for ablating contaminates and other unwanted material from an internal surface 52 using a pulsed laser beam (38). The system includes three main sub-systems: a back end (30), a work head (100), and an umbilical tube (31) to protect conduits communicating between the back end (30) and the work head (100). The back end (30) includes heavy and bulky equipment such as a laser (32), chiller (4), pressurized air source (70), suction system (84), waste containment system (82), and electric power source (78). A conveyance such as a trailer (17) may enclose the back end (30) to make it transportable. The work head (100) includes a propeller driven rotating mirror assembly (380), and a lens assembly (520). During operation, the work head (100) is inserted in the tube or pipe and the laser (32) activated. An air flow (98) in the tube drives the propeller (500) to rotate the mirror (168). The mirror assembly (380) in the work head (100) distributes pulses from the laser beam in a circle (610) described about the axis (54) of the work head (100) and directs them to the interior surface material. Ablated detritus is swept away and suctioned through a conduit attached to the tube behind the work head (100) and thence to the waste containment system (82) in the back end (30). Electric power, laser energy, control and monitor signals, air, and suction are transported between the back end (30) and the work head (100) through the conduits encased within the umbilical tube (31). The umbilical tube (31) may be used to draw the work head (100) out of the tube to clean the entire interior surface (52).
| Inventors: | Thomas; James W. (Los Altos, CA); Fuchser; Terry (Kathleen, GA) |
| Assignee: | General Lasertronics Corporation (San Jose, CA) |
| Appl. No.: | 089315 |
| Filed: | June 2, 1998 |
| Current U.S. Class: | 219/121.75; 219/121.68; 219/121.69; 219/121.85 |
| Intern'l Class: | B23K 026/38 |
| Field of Search: | 219/121.63,121.85,121.75,121.68,121.69 |
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