US Patent 11713932 Flexible tube cleaning lance positioner frame apparatus

A frame apparatus for holding a flexible lance positioning drive device adjacent to and spaced from a heat exchanger tube sheet includes an upper guide rail carrying a movable carriage supporting a drive positioner rail having a drive support carriage and an air motor drive assembly fastened to each of the carriages, each air motor drive assembly comprising an air motor having a shaft driving a spur gear through a worm gear reducer, wherein the spur gear is carried within a spur gear housing fastened to the worm gear reducer, and the air motor assembly is fastened to the carriage via the spur gear housing. The spur gear housing is selectively rotatable on the carriage between a locked position with the spur gear engaging the rail to which the carriage is mounted and an unlocked position with the spur gear disengaged with the rail to which the carriage is mounted.