Preform and container having thread groove

1. A plastic container having an upper portion, a body portion extending from said upper portion to a base, said base closing off an end of said container; said upper portion, said body portion and said base cooperating to define a receptacle chamber within said container into which product can be filled, said plastic container comprising:

a mouth formed in said upper portion defining an opening into the container; and

a radial sidewall of said upper portion defined in part by at least one groove formed therein, said at least one groove sloping gradually downward along said radial sidewall and away from said opening, wherein each of said at least one groove initiates at a groove entrance defined at an intersection between an inward sweeping radial lip and an outward sweeping radial lip.

2. The container of claim 1 wherein said upper portion further comprises:

a radial channel formed adjacent to a lower portion of said radial sidewall.

3. The container of claim 2 wherein said radial sidewall includes a land adjacent said at least one groove on an outer diameter thereof, wherein said radial sidewall defines a wall thickness measured substantially perpendicular to an axis of said opening from said land to an innermost surface of an inner diameter thereof, wherein said radial sidewall also defines a seal width measured substantially perpendicular to said axis of said opening from said land to an innermost surface of said at least one groove, and wherein said seal width of each of said at least one groove is not greater than about 50% to about 60% of said wall thickness.

4. The container of claim 1 wherein each of said at least one groove slopes gradually downward about 180 degrees to about 220 degrees around said radial sidewall.

5. The container of claim 1 wherein said inward sweeping radial lip defines an arcuate path having a decreasing radius in a clockwise direction, said decreasing radius measured from a center of said opening to said inward sweeping radial lip.

6. The container of claim 1 wherein said outward sweeping radial lip defines an arcuate path having an increasing radius in a clockwise direction, said increasing radius measured from a center of said opening to said outward sweeping radial lip.

7. A plastic container assembly comprising:

a plastic container comprising:

a finish having a first radial sidewall and formed at an opening into said container; and

at least one groove formed in said first radial sidewall, said at least one groove initiating at a groove entrance defined at an intersection between an inward sweeping radial lip and an outward sweeping radial lip, said at least one groove sloping gradually away from said opening; and

a closure member adapted to selectively mate with said first radial sidewall of said container, said closure member comprising:

a lower portion defining a closure opening;

an upper portion defining a cover; and

a second radial sidewall extending between said lower portion and said upper portion, said second radial sidewall having an inner surface defined in part by at least one thread formed thereon, said at least one thread adapted to cooperatively engage said at least one groove in an assembled position.

8. The plastic container assembly of claim 7 wherein said second radial sidewall further includes a tamper-evidence band.

9. The plastic container assembly of claim 8 wherein each of said at least one groove slopes gradually downward about 180 degrees to about 220 degrees around said first radial sidewall.

10. The plastic container assembly of claim 7 wherein each of said at least one thread initiates at a thread entrance and slopes gradually toward said cover about 160 degrees to about 200 degrees around said second radial sidewall.

11. The plastic container assembly claim 7 wherein said first radial sidewall includes a land adjacent said at least one groove on an outer diameter thereof, wherein said first radial sidewall defines a wall thickness measured substantially perpendicular to an axis of said opening from said land to an innermost surface of an inner diameter thereof, wherein said first radial sidewall also defines a seal width measured substantially perpendicular to said axis of said opening from said land to an innermost surface of said at least one groove, and wherein said seal width of each of said at least one groove is not greater than about 50% to about 60% of said wall thickness.

12. The plastic container assembly of claim 7 wherein said closure member is formed of one of a plastic and metal material suitable for thermal processing.

13. A preform adapted to be molded into a plastic container, said preform comprising:

an upper portion having a mouth corresponding to an opening into the container; and

a radial sidewall of said upper portion defined in part by at least one groove formed therein, said at least one groove sloping gradually downward along said radial sidewall and away from said opening, wherein each of said at least one groove initiates at a groove entrance defined at an intersection between an inward sweeping radial lip and an outward sweeping radial lip.

14. The preform of claim 13 wherein said radial sidewall includes a land adjacent said at least one groove on an outer diameter thereof, wherein said radial sidewall defines a wall thickness measured substantially perpendicular to an axis of said opening from said land to an innermost surface of an inner diameter thereof, wherein said radial sidewall also defines a seal width measured substantially perpendicular to said axis of said opening from said land to an innermost surface of said at least one groove, and wherein said seal width of each of said at least one groove is not greater than about 50% to about 60% of said wall thickness.

15. The preform of claim 13 wherein each of said at least one groove slopes gradually downward about 180 degrees to about 220 degrees around said radial sidewall.

16. The preform of claim 13 wherein said inward sweeping radial lip defines an arcuate path having a decreasing radius in a clockwise direction, said decreasing radius measured from a center of said opening to said inward sweeping radial lip.

17. The preform of claim 13 wherein said outward sweeping radial lip defines an arcuate path having an increasing radius in a clockwise direction, said increasing radius measured from a center of said opening to said outward sweeping radial lip.

18. The preform of claim 13 wherein a first distance measured between an inner wall surface and an outer wall surface is greater than a second distance measured between an inner diameter of said opening and an outer diameter of each of said at least one groove.

19. The preform of claim 13 wherein a first angle measured between a central longitudinal axis and an inner wall surface is greater than a second angle measured between said central longitudinal axis and an outer wall surface.