74020122
Jan 18, 1990
Jun 22, 1993
apparatus; namely, remote-controlled industrial robots for use in the inspection, maintenance, cleaning, repairing and painting of ventilation systems and ducts, and structural replacement parts therefor; compressed air-operated brushes for cleaning ventilation systems and vacuums sold as a unit with the foregoing apparatus
Machinerycleaning, maintenance, repairing and painting of ventilation systems and ducts
Building Construction and Repair