Abstract: Plastic tubing including a thermoplastic ribbon helically wrapped and heat bonded to itself to form a tubing wall and a thermoplastic reinforcement located helically around and along the tubing wall. At least a thickness of the tubing wall or a size of the thermoplastic reinforcement is varied along the tubing wall.

Abstract: Plastic tubing including a thermoplastic ribbon helically wrapped and heat bonded to itself to form a tubing wall and a thermoplastic reinforcement located helically around and along the tubing wall. At least a thickness of the tubing wall or a size of the thermoplastic reinforcement is varied along the tubing wall.

Abstract: A smooth-bore plastic tubing with an outer helical support bead is resistant to collapse and incorporates plural conductors disposed outside of the tubing bore and insulated both from ambient and from one another within the sidewall of the tubing. The conductors may have a desired relatively high thermal conductivity to tidal air flow within the tubing, while also having a comparatively high thermal resistance relative to ambient. The conductors may be electrical conductors, or fiber optic conductors.

Abstract: Plastic tubing including a thermoplastic ribbon helically wrapped and heat bonded to itself to form a tubing wall and a thermoplastic reinforcement located helically around and along the tubing wall. At least a thickness of the tubing wall or a size of the thermoplastic reinforcement is varied along the tubing wall.

Abstract: A flexible double-walled plastic tubing product includes a helically wound support bead between inner and outer walls, and an helically wrapped electrical resistance heating conductor is disposed adjacent to the inner wall in good heat transfer relation to fluid flow within the tubing product. Fluid flow within the tubing product is insulated against heat loss to ambient by the helical support bead and a trapped “dead-air” space between the walls of the tubing product. Apparatus and method for making the tubing product are disclosed.

Abstract: A flexible double-walled plastic tubing product includes a helically wound support bead between inner and outer walls, and an helically wrapped electrical resistance heating conductor is disposed adjacent to the inner wall in good heat transfer relation to fluid flow within the tubing product. Fluid flow within the tubing product is insulated against heat loss to ambient by the helical support bead and a trapped "dead-air" space between the walls of the tubing product. Apparatus and method for making the tubing product are disclosed.

Abstract: A helically wound and helically ribbed plastic tubing incorporating an electrically conductive wire and an apparatus and method for making the tubing are disclosed. A plastic ribbon is wound about an axis into a tube with one edge of each lap overlapping and heat-bonded to an edge of the preceding lap as the tubing is rotated; a conductive wire is embedded in the ribbon; and a bead is applied and heat-sealed onto the tubing, encapsulating the conductive wire during rotation of the tubing, providing a unitary structure including a conductive wire integral to a flexible tubing having a corrugated crevice-free outside and a smooth inside. Coolant is applied to the tubing for cooling the unitary ribbon, wire and bead tubing and to assist in advancing the tubing along the axis.

Abstract: A helically wound and helically ribbed plastic tubing incorporating an electrically conductive heating wire and an apparatus and method for making the tubing are disclosed. A plastic ribbon is wound about an axis into a tube with one edge of each lap overlapping and heat-bonded to an edge of the preceding lap as the tubing is rotated; a conductive wire is embedded in the ribbon; and a bead is applied and heat-sealed onto the tubing, encapsulating the conductive wire during rotation of the tubing, providing a unitary structure including a conductive wire integral to a flexible tubing having a corrugated crevice-free outside and a smooth inside. Coolant is applied to the tubing for cooling the unitary ribbon, wire and bead tubing and to assist in advancing the tubing along the axis.

Abstract: A flexible hose and method for making same, suitable for cleaning swimming pools and general vacuum applications, having contiguous turns of an extruded helical plastic bead. The strip has thin flange and leg members for receiving the bead that provide excellent crush resistant strength in I-beam fashion while providing a high degree of flexibility.

Abstract: A flexible hose and method for making same, suitable for cleaning swimming pools and general vacuum applications, having contiguous turns of an extruded helical plastic bead. The strip has thin flange and leg members for receiving the bead that provide excellent crush resistant strength in I-beam fashion while providing a high degree of flexibility.

Abstract: An apparatus for making helically wound and helically ribbed plastic tubing, comprising: means for extruding a plastic strip having a longitudinal rib; winding means for helically winding the strip about an axis into a tube with one edge of each convolution overlapping and heat bonded to an edge of a preceding convolution and with the rib of the exterior of the tube, the winding means comprising four cantilevered rolls uniformly circumferentially spaced apart around and extending in the direction of the axis and canted relative to the axis at acute angles, opposite rolls being oppositely canted; and means for driving the rolls. The apparatus further includes means for applying a coolant to the tube externally and internally thereof to cool the plastic material after the convolutions of the tube have been heat bonded together.

Abstract: The combination of a flexible, thin-walled plastic tube having thereon an external, electrically conductive, helical bead which is formed of a plastic mixed with a conductive material and which is heat sealed to the plastic of the tube. Electrical conductors are electrically connected to the bead adjacent the ends of the tube. The bead is normally opaque and the tube transparent. However, the tube may also contain a conductive material and be opaque.