Abstract: An intravascular catheter carries a helical reinforcement member embedded within at least a portion of the tubular wall of the catheter. The helical reinforcement member comprises a helical first portion having coils of greater pitch than the pitch of helical coils of a second portion. Preferably, the catheter is for insertion into brain arteries, and comprises a flexible tube having an outer diameter of no more that about 0.05 inch, for example 3 French or smaller. The flexible tube defines outer and inner tubular layers. The inner tubular layer surrounds a catheter lumen and comprises chemically inert fluorinated polymer such as PTFE. The outer tubular layer comprises at least three longitudinally spaced, connected tubular sections. The sections are of successively increasing flexibility from the proximal toward the distal catheter end.

Abstract: A tube or hollow body of a plastic material having memory characteristics is formed in a mold body having interior undulations or grooves. Pressure is applied to the interior of the plastic tube, while the tube is at a temperature above its softening point, to expand the tube into the configuration of the interior of the mold body. The pressure is maintained while the tube is cooled. After cooling, the tube is extracted axially from the mold body, and is reheated to cause the tube, by virtue of its memory characteristics, to return to the shape it had while in the mold, thereby eliminating the distortion and stretching occurring during removal from the mold. The mold body can be a tubular corrugated casing or stainless steel with a relatively thin wall, which cannot be taken apart. End assemblies are provided to hold and seal the tube ends while the tube is expanded in the mold body, by pressure applied through one of the end assemblies. The preferred plastic material is PTFE (TEFLON).

Abstract: Apparatus for continuous extrusion of tubular sections of thermoplastic material having a smooth inner surface and an annularly finned outer surface defined by alternating ribs and grooves. The apparatus comprises a die assembly made up of an outer die part and an inner die plunger. Two sets of chills define in combination a casting cavity having alternating grooves and ribs both having circular cross sections. The radius of the cross section of the grooves is smaller than that of the ribs, preferably the radius of the ribs ranges between 1.25-1.35 times greater than the radius of the grooves. For their displacement along closed loop paths the chills are provided with racks and their back sides are in meshing engagement with gears. A smoothing mandrel is provided in line with the die plunger and is cooled by a cooling fluid.

Abstract: A method for making flexible tubing with helical corrugations by forming two tube lengths simultaneously while superposed one on top of another. Two extruded sleeves of different diameter formed of uncured vulcanizable stock are slid successively in superposed relation over an elongated internal forming member having a helical surface form with helical ridges and grooves. The resulting assembly is then wrapped with a flexible cord under tension such that successive turns of the cord are in spaced, generally parallel relation and in the grooves of the forming member to press adjacent portions of the two sleeves into the grooves. The sleeves are heat-treated in this wrapped condition to form two flexible, corrugated lengths of tubing simultaneously. The cord is then unwrapped from the lengths of tubing and the lengths are removed in reverse order of assembly.

Abstract: A molded rubber article is described having an exterior or surface layer which is formed of a blend including a heat setting rubbery polymer, and a halogenated polyethylene acting as an internal mold release agent during processing and also enhancing the surface qualities of the molded article.

Abstract: A hose construction including a corrugated and a curved construction and method of making same are provided and the hose construction comprises at least one layer portion made primarily of an elastomeric material having randomly distributed elongated fibers embedded therein in substantially parallel relation with the fibers extending in a helical pattern about a reference axis of the hose construction and at an angle relative thereto.

Abstract: A molded hose construction and method of making same is provided wherein such hose construction has axially spaced convolutions and a controlled flexibility defined by alternating crests and troughs, and the hose construction has an elastomeric inner layer, an elastomeric outer layer, and an intermediate reinforcing layer made of a fabric material having a substantial open space between cooperating threads defining the fabric material; and the layers are bonded as a unitary structure by strike-through columns of elastomeric material extending through said substantial space with the alternating crests and troughs having a controlled wall thickness throughout which assures the controlled flexibility, and the crests and troughs having been formed with the elastomeric layers in a semi-cured condition to assure said controlled wall thickness thereof.

Abstract: A device for manufacturing a plastic tube with transverse or helical grooves consisting of an extruder, two movable halves of die with an inner ribbed profile and being capable of forming a hollow mould, said halves of die each provided with circular elongations for heating the region between the opening of the extruder and the beginning of the mould, an inflatable member in the tube for conforming the tube to the profile of the mould. The inflatable member comprises a movable cylinder having two expandable end discs, an inlet and an outlet for compressed medium being situated between the two end discs, the valve closing said outlet being loaded by a spring such that only pressure medium will escape after the end discs have formed a closed space with the inner side of the tube.

Abstract: Corrugated plastic tubes simultaneously feeding from a plurality of sources are doffed, stacked in nesting relation and formed into bundles of a predetermined number of tubes in accordance with the present invention. The corrugated plastic tubes are produced in continuous length in separate production lines, cut to predetermined lengths, and fed along predetermined paths to respective doffing stations where the tubes are doffed into a common hopper positioned adjacent the doffing stations. Upon a predetermined number of the tubes being doffed into the hopper and accumulated in stacked and nested relation, the tubes are advanced to a bundling station where strapping machines secure pliable strapping elements around the stacked and nested tubes to form the same into compact bundles. The bundles are then removed from the bundling station ready for shipment or storage.