Valve stem for use in a metering valve of a metered dose inhaler

• US 20030127464A1
• Filed: 12/30/2002
• Published: 07/10/2003
• Est. Priority Date: 12/31/2001
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Hodson, Peter D., Castro, Gustavo H., Bryant, Andrew M., Mahon, Gary D., Greenleaf, David J.
• Granted Patent: US 6,863,195 B2
• Time in Patent Office: Days
• US Class Current: 222/1
• CPC Class Codes: B65D 83/54 Metering valves ; Metering valve assemblies
• CPC Class Codes: G01F 11/12 of the valve type, i.e. the separating being effected by fluid-tight or powder-tight movements involving the tilting or inverting of the supply vessel G01F11/26
• CPC Class Codes: G01R 11/12 Arrangements of bearings

Abstract

Valve stems for use in an aerosol metering valve are described herein. The valve stems include structures designed to limit the likelihood and extent to which a gasket can intrude into an opening in the valve stem. The valve stems described herein also limit the likelihood and extent of damage to the gasket caused by repeated use of the metering valve.

Claims

1. A valve stem for use in an aerosol metering valve comprising a sealing gasket, the valve stem comprising:

a stem portion comprising a discharge outlet, and

a body portion comprising;

i) a body wall that comprises an exterior surface and an interior surface, the interior surface defining an interior space,

ii) an inlet through the body wall in fluid communication with the interior space,

iii) an outlet through the body wall in fluid communication with the interior space and comprising at least one opening, and

iv) at least one gasket-protective component configured to limit seal intrusion.

2. The valve stem of claim 1 wherein the gasket-protective component comprises at least one rounded or beveled edge of the at least one outlet opening.

3. The valve stem of claim 2 wherein the gasket-protective component comprises at least one rib that is substantially continuous with the exterior surface of the body wall and at least partially traverses the outlet opening.

4. The valve stem of claim 3 wherein the rib completely traverses the outlet opening.

5. The valve stem of claim 1 wherein the valve stem has a longitudinal axis and the gasket-protective component comprises at least a portion of at least one outlet opening that is constructed such that its longitudinal position on the body wall is different than at least one other portion of the at least one outlet opening.

6. The valve stem of claim 5 wherein the longitudinal position of a portion of the outlet opening depends sinusoidally on its radial position around the body wall.

7. The valve stem of claim 6 wherein the outlet opening comprises at least one rib that is substantially continuous with the exterior surface of the body wall and at least partially traverses the outlet opening.

8. The valve stem of claim 7 wherein the rib completely traverses the outlet opening.

9. The valve stem of claim 1 wherein the gasket-protective component comprises a plurality of outlet openings wherein at least one outlet opening is separated from another outlet opening by a gasket-supportive rib comprising a portion of the exterior surface of the body wall.

10. The valve stem of claim 1 wherein the gasket-protective component comprises at least a portion of the exterior surface of the body wall around at least one outlet opening that is substantially planar.

11. The valve stem of claim 10 wherein a transverse cross-section of the body portion of the valve stem forms a square.

12. A valve stem for use in an aerosol metering valve comprising a sealing gasket, the valve stem comprising:

a stem portion comprising a discharge outlet, and

a body portion comprising;

i) a body wall that comprises an exterior surface and an interior surface, the interior surface defining an interior space,

ii) an inlet through the body wall in fluid communication with the interior space,

iii) an outlet through the body wall in fluid communication with the interior space and comprising at least one opening, and

iv) means for limiting intrusion of the sealing gasket into the at least one opening.

13. An aerosol metering valve comprising:

a) a housing that comprises an internal chamber defined by one or more chamber walls, and a housing gasket having walls that define a housing aperture;

b) at least one port through the housing in fluid communication with the internal chamber;

c) a metering gasket that comprises a major surface, at least a portion of which forms a face seal with at least a portion of at least one chamber wall of the metering valve housing, and an aperture that defines a sealing surface; and

d) a valve stem that comprises;

a stem portion that passes through the housing aperture in slidable, sealing engagement with the housing gasket, the stem portion comprising a discharge outlet, and

a body portion comprising;

i) a body wall that comprises an exterior surface in slidable, sealing engagement with at least a portion of the metering gasket sealing surface, and an interior surface that defines an interior space,

ii) an inlet through the body wall in fluid communication with the interior space,

iii) an outlet through the body wall in fluid communication with the interior space and comprising at least one opening, and

iv) at least one gasket-protective component.

14. A method of reducing seal intrusion in a metering valve, the method comprising:

providing a metering gasket that comprises a major surface, and an aperture that defines a sealing surface;

providing a valve stem that comprises a body portion comprising;

i) an exterior surface in slidable, sealing engagement with the sealing surface of the metering gasket, and

ii) at least one opening in the exterior surface of the body wall; and

reconfiguring the valve stem to comprise at least one gasket-protective component, the gasket-protective component configured to reduce intrusion of the metering gasket into the at least one opening.

15. The method of claim 14 wherein at least a portion of the exterior surface of the body wall is curved so that an opening in the curved portion of the exterior surface defines a chord length across the opening;

and

wherein reconfiguring the valve stem comprises adding one or more gasket-supportive ribs that comprise a portion of the exterior surface of the body wall such that the chord length of at least one opening is shortened.

16. The method of claim 14 wherein at least a portion of the exterior surface of the body wall is curved so that an opening in the curved portion of the exterior surface defines a chord length across the opening;

and

wherein reconfiguring the valve stem comprises repositioning one or more gasket-supportive ribs that comprise a portion of the exterior surface of the body wall such that the chord length of at least one opening is shortened.