Grinding system

1. A tissue grinding system comprising:

a mortar container having an open top portion and a bottom portion having a first interior grinding surface and a wall portion interconnecting said top and bottom portions for defining a hollow interior collection chamber;

a modular pestle assembly including a universal pestle shaft having at its proximate end an actuator portion extending above said top portion and at its distal end a mounting portion for receiving one of a set of pairs of matching tips and pestle collars, said pestle shaft extending through said pestle collar, said pestle tip having a second grinding surface for engaging said first grinding surface; and

a closure device sealingly engageable with said pestle assembly and said open top portion for sealing said container and the collection chamber between said grinding surfaces and said top portion of said mortar container.

2. The tissue grinding system of claim 1 in which each said pestle collar includes a mounting hole for engaging said pestle shaft and said mounting portion includes a collar stop element for defining the position of said collar on said pestle shaft.

3. The tissue grinding system of claim 1 in which each said pestle tip includes a drive hole and the distal end of said pestle shaft includes a drive stub for engaging said drive hole for rotating said pestle tip and said second grinding surface relative to said first grinding surface.

4. The tissue grinding system of claim 3 in which said pestle tip is substantially solid except for said drive hole.

5. The tissue grinding system of claim 3 in which said pestle tip is substantially hollow except for a hub containing said drive hole.

6. The tissue grinding system of claim 1 in which each said collar has an edge engaging a congruent edge of the associated pestle tip.

7. The tissue grinding system of claim 6 in which each said pestle collar and tip are joined at said edges.

8. The tissue grinding system of claim 7 in which said pestle collar has an inclined wall extending from said mounting hole to said edge of said collar for shedding grinding medium downwardly toward said grinding surfaces.

9. The tissue grinding system of claim 1 in which said closure includes a cap engaged with said open top portion of said container and said cap includes a resilient sealing member for sealing between said cap and said top portion of said container and between said cap and said pestle assembly.

10. The tissue grinding system of claim 9 in which said pestle shaft includes an upper cap stop element for limiting movement of said pestle shaft into said container.

11. The tissue grinding system of claim 1 in which said pestle shaft includes a lower cap stop element for limiting movement of said pestle shaft out of said container.

12. A grinding system comprising:

a mortar container having an open top portion and a bottom portion having a first interior grinding surface and a wall portion interconnecting said top and bottom portions for defining a hollow interior collection chamber;

a modular pestle assembly including a universal pestle shaft having at its proximate end an actuator portion extending above said top portion and at its distal end a mounting portion for receiving one of a set of pairs of matching tips and pestle collars, said pestle shaft extending through said pestle collar, said pestle tip having a second grinding surface for engaging said first grinding surface; and

a closure device sealingly engageable with said pestle assembly and said open top portion for sealing said container and the collection chamber between said grinding surfaces and said top portion of said mortar container.

13. The grinding system of claim 12 in which each said pestle collar includes a mounting hole for engaging said pestle shaft and said mounting portion includes a collar stop element for defining the position of said collar on said pestle shaft.

14. The grinding system of claim 12 in which each said pestle tip includes a drive hole and the distal end of said pestle shaft includes a drive stub for engaging said drive hole for rotating said pestle tip and said second grinding surface relative to said first grinding surface.

15. The grinding system of claim 14 in which said pestle tip is substantially solid except for said drive hole.

16. The grinding system of claim 14 in which said pestle tip is substantially hollow except for a hub containing said drive hole.

17. The grinding system of claim 12 in which each said collar has an edge engaging a congruent edge of the associated pestle tip.

18. The grinding system of claim 17 in which each said pestle collar and tip are joined at said edges.

19. The grinding system of claim 18 in which said pestle collar has an inclined wall extending from said mounting hole to said edge of said collar for shedding grinding medium downwardly toward said grinding surfaces.

20. The grinding system of claim 12 in which said closure includes a cap engaged with said open top portion of said container and said cap includes a resilient sealing member for sealing between said cap and said top portion of said container and between said cap and said pestle assembly.

21. The grinding system of claim 20 in which said pestle shaft includes an upper cap stop element for limiting movement of said pestle shaft into said container.

22. The grinding system of claim 12 in which said pestle shaft includes a lower cap stop element for limiting movement of said pestle shaft out of said container.

23. A grinding system comprising:

a mortar container having an open top portion and a bottom portion having a first interior grinding surface and a wall portion interconnecting said top and bottom portions for defining a hollow interior collection chamber;

a modular pestle assembly including a universal pestle shaft having at its proximate end an actuator portion extending above said top portion and at its distal end a mounting portion for receiving one of a set of pairs of matching tips and pestle collars, each said collar having an edge engaging and joining a congruent edge of an associated pestle tip, said pestle tip having a second grinding surface for engaging said first grinding surface; and

a closure device sealingly engageable with said pestle assembly and said open top portion for sealing said container and the collection chamber between said grinding surfaces and said top portion of said mortar container.

24. A grinding system comprising:

a mortar container having an open top portion and a bottom portion having a first interior grinding surface and a wall portion interconnecting said top and bottom portions for defining a hollow interior collection chamber;

a modular pestle assembly including a universal pestle shaft having at its proximate end an actuator portion extending above said top portion and at its distal end a mounting portion for receiving one of a set of pairs of matching tips and pestle collars, said pestle collar including a mounting hole and an inclined wall extending from said mounting hole to an edge of said collar for shedding grinding medium downwardly, said pestle tip having a second grinding surface for engaging said first grinding surface; and

a closure device sealingly engageable with said pestle assembly and said open top portion for sealing said container and the collection chamber between said grinding surfaces and said top portion of said mortar container.