at the outset , it should be clearly understood that like reference numerals are intended to identify the same structural elements , portions or surfaces , consistently throughout the several drawing figures , as such elements , portions or surfaces may be further described or explained by the entire written specification , of which this detailed description is an integral part . unless otherwise indicated , the drawings are intended to be read ( e . g ., cross - hatching , arrangement of parts , proportion , degree , etc .) together with the specification , and are to be considered a portion of the entire written description of this invention . as used in the following description , the terms “ horizontal ”, “ vertical ”, “ left ”, “ right ”, “ up ” and “ down ”, as well as adjectival and adverbial derivatives thereof ( e . g ., “ horizontally ”, “ rightwardly ”, “ upwardly ”, etc . ), simply refer to the orientation of the illustrated structure as the particular drawing figure faces the reader . similarly , the terms “ inwardly ” and “ outwardly ” generally refer to the orientation of a surface relative to its axis of elongation , or axis of rotation , as appropriate . referring now to the drawings and , more particularly , to fig1 and 2 thereof , this invention provides an improved ozone applicator cup , of which the presently preferred embodiment is generally indicated at 15 . cup 15 is shown as broadly including a body 16 and a liner 17 . body 16 and liner 17 are generally cylindrically shaped members . fig4 shows body 16 of cup 15 . fig5 is a sectional view of body 16 shown in fig4 , taking generally on line 5 — 5 of fig4 . referring to fig5 , body 16 is a specially configured member elongated along axis x — x and is bounded by a rightwardly - facing annular vertical surface 18 , a rightwardly and outwardly - facing frusto - conical surface 19 , an outwardly - facing horizontal cylindrical surface 20 , a leftwardly - facing annular vertical surface 21 , an inwardly - facing horizontal cylindrical surface 22 , a rightwardly - facing annular vertical surface 23 , an inwardly - facing horizontal cylindrical surface 24 , a leftwardly - facing annular vertical surface 25 , and an inwardly - facing horizontal cylindrical surface 26 , joined at its right marginal end to the inner marginal end of surface 18 . surface 26 generally defines cup chamber 28 . fig6 shows liner 17 of cup 15 . fig8 is a sectional view of liner 17 , taken generally on line 8 — 8 of fig7 . referring to fig8 , liner 17 is a specially - configured solid member elongated along axis x — x , and is bounded by a rightwardly - facing annular vertical surface 29 , an outwardly - facing horizontal cylindrical surface 30 , a leftwardly - facing annular vertical surface 31 , an inwardly - facing horizontal cylindrical surface 32 , a rightwardly - facing annular vertical surface 33 , an inwardly - facing horizontal cylindrical surface 34 , a leftwardly - facing annular vertical surface 35 , and an inwardly - facing horizontal cylindrical surface 36 , joined at its right marginal end to the inner marginal end of surface 29 . as shown in fig1 – 2 , liner 17 is encased in the bottom portion of body 16 . in particular , liner 17 fits within the recess defined by surfaces 23 , 24 and 25 of body 16 . thus , surface 29 of liner 17 abuts surface 25 of body 16 , surface 30 of liner 17 abuts surface 24 of body 16 , and surface 31 of liner 17 abuts surface 23 of body 16 . thus , when fully formed , the diameter of cylindrical surface 32 and the diameter of cylindrical surface 22 are the same . also , the diameter of cylindrical surface 36 is approximately the same as the diameter of the cylindrical surface 26 . cup 15 is manufactured using a two - part molding process in a controlled and clean environmental . the first step of the process is to form liner 17 . liner 17 is formed by conventional injection molding . the injection mold is a 32 - cavity , hot runner spi 102 production mold . thus , each cycle produces 32 liners and the plastic remains molten right up to injection into the part . spi refers to the society of plastics industry , inc . classifications . a class 102 mold generally has a cycle life of less than one million cycles and a minimum base hardness of 280 bhn . the material used to form liner 17 is a plastic material . it has a good abrasion resistance and overmold adhesion to polypropylene and good compression set . in the preferred - embodiment , it has the following characteristics : specific gravity 0 . 89 ref . astm d792 , 23 / 23 ° c . shore a hardness 68 ref . astm d2240 , 10 sec . tensile strength ( psi ) 952 ref . astm d412 - die c , 2 hrs , 23 ° c . elongation (%) 639 ref . astm d412 - die c , 2 hrs , 23 ° c . modulus @ 300 % ( psi ) 551 ref . astm d412 - die c , 2 hrs , 23 ° c . viscosity @ 11170 / sec ( pa - sec ) 6 . 4 200 ° c . as a result , it will not unduly deform when fit onto the outlet of a handpiece for an ozone delivery device . the versalloy xl 9070x - 1 product sold by gls corporation , of 833 ridgeview dr ., mchenry , ill . 60050 may be employed in the preferred embodiment . the second step is the overmold of body 16 . liner 17 is insert molded with body 16 being formed over it ( overmolded ). in the preferred embodiment , the injection mold is a 16 - cavity , hot runner spi 102 production mold with interchangeable 16 - cavity sets for each of the desired sizes . a snap core pin protrudes up from the bottom of the cavity to simulate the outlet of the handpiece and has the same features as the particular handpiece with which the cup will be used . the liner is positioned on the pin and then overmolded with body 16 . using this type of overmolding , the physical characteristics of liner 17 and body 16 can be different . accordingly , liner 17 is designed with features , such as higher resiliency to deformation , to allow for an appropriate fit of cup 15 onto a handpiece , while body 16 is designed with features , such as higher pliability and softness , to allow for cup 15 to create a seal around a tooth surface to expose the subject area to gas circulated in chamber 28 . the material used to form overmolded body 16 is a thermoplastic rubber compound . in the preferred embodiment , it has the following characteristics : specific gravity 0 . 86 ref . astm d792 , 23 / 23 ° c . shore a hardness 3 ref . astm d2240 , 10 sec . tensile strength ( psi ) 300 ref . astm d412 - die c , 2 hrs , 23 ° c . elongation (%) 1 , 516 ref . astm d412 - die c , 2 hrs , 23 ° c . modulus @ 300 % ( psi ) 25 ref . astm d412 - die c , 2 hrs , 23 ° c . viscosity @ 11170 / sec ( pa - sec ) 2 . 3 200 ° c . color clear the versaflex cl2000x compound sold by gls corporation , of 833 ridgeview dr ., mchenry , ill . 60050 may be employed in the preferred embodiment . with respect to both liner 17 and body 16 , a color concentrate may be added , with different colors identifying different part sizes . the present invention contemplates that many changes and modifications may be made . for example , the particular dimensions of the preferred embodiment may be altered as may be the cross - sectional geometry . for example , body 16 and liner 17 may have an oval geometry rather than a cylindrical geometry , or surface 26 may be tapered with a leftwardly and inwardly - facing frusto - conical surface . therefore , while the presently - preferred form of the cup has been shown and described , and several modifications thereof discussed , persons skilled in this art will readily appreciate that various additional changes and modifications made be made without departing from the spirit of the invention .
a cup for use with the handpiece of an apparatus for applying gas to a portion of a tooth comprising a liner configured and arranged to engage a gas dispensing handpiece , a body defining a gas exposure chamber , the body having a higher resiliency to deformation than the liner . the body may be so deformable that it forms against the surface of a tooth to effect a seal and to expose a portion of the tooth to gas circulated in the chamber . the body may overmold the liner and may be formed of thermal - plastic rubber , and the liner may be formed of a plastic material . the gas exposure chamber may be cylindrical .