Multicompartment mixing capsule

• US 5,394,980 A
• Filed: 12/23/1993
• Issued: 03/07/1995
• Est. Priority Date: 06/30/1987
• Status: Expired due to Fees

• Current Assignee: Min H. Tsai
• Original Assignee: Min H. Tsai
• Inventors: Tsai, Min H.
• Primary Examiner(s): FIDEI, DAVID
• Application Number:
  US08/173,712
• Time in Patent Office: 439 Days
• Field of Search: 206/219, 206/220, 206/221, 206/222, 206/368, 206/63.5, 220/281, 215/250, 215/DIG. 8
• US Class Current: 206/63.5
• CPC Class Codes: A61C 5/66 Capsules for filling material
• CPC Class Codes: B65D 81/3211 coaxially and provided with means facilitating admixture
• CPC Class Codes: Y10S 215/08 Mixing

Abstract

A multicompartment mixing capsule which is particularly useful for storage and subsequent intermixing of mercury and silver or a silver alloy to form a dental amalgam material. The amalgam components are contained in separate capsule chambers which are insulated by a diaphragm having a thin frangible perimeter, and a thickened and strengthened center portion. A pestle in one of the chambers impacts the diaphragm during initial capsule shaking in an amalgamator to rupture the frangible diaphragm perimeter, and thereby to permit complete and unimpeded intermixing of the amalgam components.

Claims

1. A multicompartment mixing capsule, comprising:

a hollow central body having a passage therethrough which is closed by an internal barrier diaphragm positioned between first and second ends of the passage, the diaphragm having a thin frangible perimeter integrally formed with the central body, and a thickened center portion which is thereby strengthened against rupture, the diaphragm and thickened center portion being substantially circular, the diaphragm radius being at least about 1.5 times the radius of the thickened center portion;

a first end cap inserted in the first end of the central-body passage to form a first chamber between the first end cap and the diaphragm;

a second end cap inserted in the second end of the central-body passage to form a second chamber between the second end cap and diaphragm;

the end caps making an interference fit in the central body, and wherein the diaphragm has a thin annular portion extending between the perimeter and thickened center portion, the annular portion having sufficient elasticity to withstand without breakage radial stresses in the central body arising from insertion of the end caps; and

a pestle in one of the chambers to impact against and separate the diaphragm at the perimeter when the capsule is shaken.

2. The capsule defined in claim 1 wherein each end cap is of one-piece integrally molded construction without relatively movable parts.

3. The capsule defined in claim 1 wherein the central body and end caps are made of polyethylene plastic.

4. The capsule defined in claim 1 wherein the diaphragm radius is about twice the radius of the center portion.

5. The capsule defined in claim 1 wherein the diaphragm thickened center portion has a thickness in the range of 3 to 10 times the thickness of the annular portion.

6. The capsule defined in claim 1 wherein the diaphragm annular portion has a thickness in the range of 0.004 inch to 0.012 inch.

7. The capsule defined in claim 6 wherein the diaphragm annular portion has a thickness of about 0.006 inch to 0.007 inch.

8. A self-activating multicompartment amalgam mixing capsule, comprising:

a hollow and integrally molded tubular central body having a bore therethrough which is interrupted by a diaphragm extending across the bore and sealing first and second ends of the bore from each other, the diaphragm having a thin frangible perimeter integrally formed with the body, and a center portion which is strengthened relative to the frangible perimeter by having an increased thickness relative to the perimeter, the diaphragm perimeter and thickened center portion being coaxially circular to define an annular diaphragm portion therebetween, the perimeter radius being at least about 1.5 times the radius of the center portion;

a first end cap fitted in the first end of the body bore to define a first closed chamber between the first end cap and the diaphragm;

a second end cap fitted in the second end of the body bore to define a second closed chamber between the second end cap and the diaphragm;

a pestle in the first chamber;

a first amalgam component in the first chamber; and

a second amalgam component in the second chamber;

whereby shaking of the capsule causes the pestle to impact against the diaphragm to rupture the diaphragm perimeter to permit intermixing of the amalgam components.

9. The capsule defined in claim 8 wherein the diaphragm center portion has central thickness in the range of about 3 to about 10 times the thickness of the annular portion.

10. The capsule defined in claim 9 wherein the thickness of the annular portion is in the range of about 0.004 inch to 0.012 inch.

11. The capsule defined in claim 10 wherein the thickness of the annular portion is about 0.006 inch to 0.007 inch.

12. The capsule defined in claim 11 wherein the first chamber is axially longer than the second chamber, and wherein the end caps make a snug interference fit in the central body, each end cap being of one-piece integrally molded construction without relatively movable parts.