Appeal No. 2000-1763 Page 5
Application No. 09/227,037
A disposable tubular device of the present invention (e.g., the syringe tip
24) is preferably made by a dual-extrusion method. A first material is extruded
through a first die to form an inner tube 36. This die is configured such that
extrusion of the first material through the first die forms an elongate tube with
elongate flutes. The flutes extend along substantially the entire length of the
tube. The fluted tube is then passed longitudinally through a second die while a
second material is extruded through the second die and around the inner tube.
The extruded tubes are then cut to length to form the tip 24. The second die is
configured so that the outer tube 38 (sleeve) so formed fits snugly over the inner
tube 36. The sleeve 38 constitutes a tube-support structure for maintaining the
general overall shape of the inner tube 36. The flutes 46 and a portion of an
inner surface 50 of the sleeve 38 define a plurality of fluid passageways 52. The
first and second materials are selected so that the outer tube of the tip 24 is stiffer
than the inner tube at the typical operating temperatures of the syringe (e.g.,
temperatures in the range of 50 F. to 110 F.).o o
We have carefully reviewed the appellant's specification, paying special attention to the
above-mentioned portions alluded to by the examiner, but we perceive therefrom no indication
that extrusion of a first material through a first die to form the tube and movement of the tube
through a second die while a second material is extruded through the second die to form the
tube-support structure is critical to the invention. As we see it, the critical features of the
invention are the steps of forming an inner tube of a first pliable, resilient material adapted to
form a fluid-tight seal with a medical instrument and forming a tube-support structure (outer
tube) having a stiffness and hardness greater than that of the inner tube so as to make a tubular
structure capable of releasable and sealing connection to a medical instrument. As pointed out
in column 3, lines 33-38, of the appellant's specification, the inner tube and outer tube
preferably are held together by a close friction fit or, alternatively, may be bonded together by
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