Patent ID: 8887343

Claim:
A system for axially propelling a hose, comprising: a system housing; a tractor element disposed in the system housing and including: a tractor housing with a through-bore; and, a first protrusion roller rotatably fastened to the tractor housing at a non-perpendicular angle with respect to the axial through bore and extending through the tractor housing into the through-bore; a hose assembly including a substantially helical coil disposed about a hose; a second protrusion roller rotatably fastened to the tractor housing circumferentially adjacent the first protrusion roller at a non-perpendicular angle with respect to a first direction along the axial through bore and at a different angle than the fastened angle of the first protrusion roller with respect to the first direction along the axial through bore and extending through the tractor housing into the through-bore, wherein adjacent first and second protrusion rollers extend through a common opening in the tractor housing, and wherein: the hose assembly can be disposed in the through-bore so that the second protrusion roller contacts a second flank portion of the coil different from the first flank portion of the coil; as the tractor housing is rotated by the actuator in a second rotational direction, opposite the first rotational direction: the second protrusion roller exerts a second displacement force on the coil; the hose assembly reacts to the second displacement force by displacing in a second axial direction opposite the first axial direction; and, an actuator within the system housing mounted adjacent the tractor housing for rotating the tractor housing with respect to the system housing, wherein: the tractor element is fixed in the system housing with respect to axial movement; the hose assembly can be disposed in the through-bore so that the first protrusion roller contacts only a first flank portion of the coil; and, as the tractor housing is rotated by the actuator in a first rotational direction: the first protrusion roller rolls along the first flank portion of the coil and exerts a first displacement force on the coil; and, the hose assembly reacts to the first displacement force by displacing in a first axial direction.