Cartridge piston

• US 20080083789A1
• Filed: 10/09/2007
• Published: 04/10/2008
• Est. Priority Date: 10/06/2006
• Status: Active Grant

• Current Assignee: Medmix Switzerland AG
• Original Assignee: Sulzer MixPac AG (Sulzer AG)
• Inventors: Brugner, Nikolaus
• Granted Patent: US 7,748,577 B2
• Time in Patent Office: Days
• US Class Current: 222/386
• CPC Class Codes: A61M 5/31511 Piston or piston-rod constructions, e.g. connection of piston with piston-rod A61M5/5066 takes precedence
• CPC Class Codes: A61M 5/31513 Piston constructions to improve sealing or sliding
• CPC Class Codes: B05C 17/00576 characterised by the construction of a piston as pressure exerting means, or of the co-operating container
• CPC Class Codes: B05C 17/00579 comprising means for allowing entrapped air to escape to the atmosphere
• CPC Class Codes: B65D 83/0005 Containers or packages provided with a piston or with a movable bottom or partition having approximately the same section as the container B65D83/0072 takes precedence

Abstract

The cartridge piston has an outer wall, an inner support body and radial connection webs between the outer wall and the inner support body. In order to ensure a good sealing behaviour under unilateral strain or asymmetric strain by a pressing plunger, a stiffening body connected to the connection webs is provided between the outer wall and the inner support body. The connection webs have a gap that extends at least up to half the height of the cartridge piston at the lower side of the cartridge piston between the outer wall and the stiffening body.

Claims

1. A cartridge piston comprising

an outer peripheral wall;

an inner support body within said outer peripheral wall;

a stiffening body concentrically between said outer wall and said inner support body; and

radially disposed connection webs between said outer wall and said stiffening body and between said stiffening body and said inner support body, at least one of said connection webs between said outer wall and said stiffening body defining a gap extending at least up to half the height of the cartridge piston at the lower side of the cartridge piston.

2. A cartridge piston in accordance with claim 1 wherein said gap converges upwardly in wedge shape from the lower side of the cartridge piston.

3. A cartridge piston in accordance with claim 1 further comprising a cover transverse to said outer wall and said inner support body and wherein said outer wall is spaced from said cover to define an annular groove therebetween of V-shaped cross-section.

4. A cartridge piston in accordance with claim 3 further comprising a cover plate disposed over said cover.

5. A cartridge piston in accordance with claim 4 further comprising a radially inwardly directed annular lip on said support body and a conical spigot depending from said cover plate and projecting through said annular lip to form a bleed valve therewith.

6. A cartridge piston in accordance with claim 4 further comprising a plurality of spacers on said cover for spacing said cover plate from said cover with a predetermined small gap.

7. A cartridge piston in accordance with claim 1 wherein said stiffening body has a lower side terminating flush with the lower side of said outer wall.

8. A cartridge piston in accordance with claim 1 wherein said stiffening body is annular.

9. A cartridge piston in accordance with claim 1 further comprising a second stiffening body arranged between said first stiffening body and said support body.

10. A cartridge piston in accordance with claim 1 wherein said outer wall has a radially outwardly projecting upper rim with a sealing edge and a radially outwardly projecting lower rim configured as a support lip.

11. A cartridge piston comprising

a cover of annular shape;

an outer peripheral wall extending from said cover;

an inner support body extending from said cover concentrically within said outer peripheral wall;

a stiffening body extending from said cover concentrically between said outer wall and said inner support body;

a first array of radially disposed connection webs between said outer wall and said stiffening body, at least some of said connection webs defining a gap relative to said outer wall and extending at least up to half the height of the cartridge piston at the lower side of the cartridge piston whereby said outer wall is hingedly connected to said cover to pivot relative to said cover; and

a second array of radially disposed connection webs connected to and between said stiffening body and said inner support body to form a rigid core for transferring a force therethrough.

12. A cartridge piston as set forth in claim 11 wherein said outer peripheral wall is spaced from said cover to define an annular groove therebetween of V-shaped cross-section.

13. A cartridge piston as set forth in claim 12 further comprising a cover plate disposed over said cover and having a peripheral outer rim engaged in said annular groove.

14. A cartridge piston as set forth in claim 13 further comprising a radially inwardly directed annular lip on said support body and an axially movable conical spigot depending centrally from said cover plate and projecting through said annular lip to form a bleed valve therewith.

15. A cartridge piston in accordance with claim 14 further comprising a plurality of spacers on said cover for spacing said cover plate from said cover with a predetermined small gap to define a path for air from within a cartridge through said gap and said bleed valve.

16. A cartridge piston as set forth in claim 11 wherein said outer wall has a radially outwardly projecting upper rim with a sealing edge and a radially outwardly projecting lower rim configured as a support lip.