referring now to the drawings , and in particular fig1 the present invention is shown generally at 10 comprised of a first oxygen supply tube section 12 connected to a joint cannula connector 14 that has two independent oxygen supply tubes 16 and 18 , all of which connect into the nasal cannula 20 that has two independent oxygen supply tubes 22 which are typically inserted into the nostrils of the patient . an oxygen supply tank ( not shown ) is connected to a rotatable coupling 26 through an oxygen flexible lumen supply tube section 28 shown connected to rotatable coupling 26 through rigid conduit 24 . the purpose of rotatable coupling 26 is to allow rotation between oxygen supply tube section 28 and oxygen supply tube section 12 . by virtue of the rotatable coupling , including a rotatable bearing 30 mounted inside rotatable coupling 26 housing 26c , the oxygen flexible supply tube section 28 can be physically rotated in either direction relative to flexible oxygen supply tube section 12 . the purpose of this independent rotation , which allows each oxygen tube section to rotate relative to each other , is to prevent any type of twisting , which can be initiated by the movement of the patient walking around with the oxygen supply connected to the cannula attached to the patient . flexible tube section 28 contains an annular , specially shaped groove 28a ( fig3 ) near the end of the tube 28 which allows it to be sealably connected to a rigid conduit 24 that is connected to one end of flexible tube section 28 and sealably into the bearing inner race 30b interior passage . the outside of the rotatable coupling 26 is formed of a rigid plastic or metal housing 26c that is unitarily connected to a rigid oxygen conduit 26a and includes an annular flange 26d that allows for a sealable connection between the rotatable coupling 26 and the end of flexible tube section 12 . referring to fig3 the rotatable coupling 26 includes a rigid oxygen receiving conduit 26a that is in fluid communication with a cylindrical chamber 26b inside the housing 26c . a rotatable annular bearing 30 includes ball bearings 34 , a plurality of which are annularly mounted between an outer race 30a which is a cylindrical or annular ring made of a thin , stainless steel metal having a groove for the ball bearings 34 , and an inner stainless steel annular race 30b , all of which makes up the entire bearing . the bearing 30 disclosed shows ball bearings 34 ( fig3 ) ( that could be barrel type cylindrical roller bearings ) and is made without a lubricant so the entire bearing structure is dry . the outer diameter of the outer race 30a is sized to fit snugly and be held in place inside the recessed portion 26d of cylindrical chamber 26b , whose inside diameter is substantially the same as the outside diameter of outer race 30a so that the bearing , once inserted , will stay firmly in place . the inside diameter of inside race 30b is sized to be approximately the outside diameter of conduit 24 so that conduit 24 fits snugly inside bearing 30 . a rigid plastic conduit 24 allows oxygen to flow therethrough , completing the oxygen supply passage through the rotatable coupling 26 as follows . the cylindrical portion of conduit 24 between an annular flange 24b and the end of tube 28 acts as the support for the inner race of bearing 30 and is mounted therethrough . the bearing 30 is held in place inside of housing 26 as described above . thus , the bearing 30 holds the conduit 24 in place . a conical portion 46 helps stop oxygen from escaping at the junction of the inside surface of housing chamber 26 and flange 24a . a second , tapered , conical flange 24c near the end of conduit 24 fits snugly in a shaped groove 28a in the flexible tube section 28 that prevents disengagement between the conduit 24 and the flexible oxygen supply tube section 28 and at the same time forming a seal between the end of tube section 28 and the end of conduit 24 . the opposite end of rotatable coupling housing 26 includes a rigid conduit 26a whose outside diameter fits snugly inside of flexible tube section . 12 tube 12 has a groove 12a near its end to fit snugly and sealably against a conical flange 26e mounted at the end of the housing conduit 26a . fig1 and 2 show the conduit 24 in an exploded view relative to the rotatable coupling 26 . once conduit 24 is firmly and sealably in place inside of bearing 30 , the rotatable coupling will not leak oxygen when oxygen under pressure is received through supply tube section 28 from an oxygen source under pressure ( 2 or 3 pounds psi above atmospheric ) as the oxygen flows through the rotatable coupling into conduit 26a and then into supply tube section 12 . the rotatable coupling 26 allows rotation between the outer bearing race 30a and inner bearing race 30b , thus allowing free rotational movement of supply tube section 28 relative to supply tube section 12 . by permitting relative rotational movement , twisting the supply tube section 12 or the supply tube section 28 will not pinch or cause stoppage or occlusion of oxygen flowing through the system to the cannula 20 . thus , the patient can freely move about without fear or danger of twisting the flexible tubing in such a way that would cut off the oxygen supply . in a typical application as shown in fig2 oxygen can be supplied from a tank or wall connection leading to a tank that is connected directly to an oxygen supply tube 28 . in this embodiment , only one rotatable coupling 26 is used . for longer embodiments of the invention , additional rotatable couplings 26 can be used along various length tube sections 12 or 28 of the oxygen conduit . the rotatable coupling 26 includes a dry bearing and material such as stainless steel or even a plastic that will not chemically interact with pure oxygen flowing through the system to insure that the oxygen supplied to the patient is pure . the ball bearing 30 includes a pair of disc - shaped ball bearing retainers 40 which isolate the ball bearings 34 from outside the bearings and act as supports between the inner and outer races 30a and 30b , forming a unit bearing where the ball bearings are shielded from the outside environment . the retainer 40 fits on each side of the bearings . the instant invention has been shown and described herein in what is considered to be the most practical and preferred embodiment . it is recognized , however , that departures may be made therefrom within the scope of the invention and that obvious modifications will occur to a person skilled in the art .
an oxygen delivery conduit for supplying oxygen continuously under pressure to a patient wearing a nasal cannula that prevents occlusion or pinching of the oxygen tube sections supplying the oxygen to insure a continuous oxygen supply to the patient . first and second oxygen supply tube sections rotate relative to each other freely while sealed to prevent crimping , pinching or occlusion of the tubing . the rotatable coupling includes roller or ball bearings mounted in a sealed , non - lubricated bearing structure in a coupling housing .