Hermetic seal leak detection apparatus with variable size test chamber

• US 9,097,609 B1
• Filed: 04/30/2013
• Issued: 08/04/2015
• Est. Priority Date: 04/30/2013
• Status: Active Grant

• Current Assignee: The Government Of The United States Of America, As Represented By The Secretary Of The Navy
• Original Assignee: United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration
• Inventors: Kelley, Anthony R.
• Primary Examiner(s): Martin, Laura
• Assistant Examiner(s): Shah, Samir M
• Application Number:
  US13/874,182
• Time in Patent Office: 826 Days
• Field of Search: 73/37, 73/40, 73/407, 73/493, 73/498
• US Class Current: 1/1
• CPC Class Codes: G01M 3/32 for containers, e.g. radiators
• CPC Class Codes: G01M 3/3281 removably mounted in a test cell

Abstract

The present invention is a versatile hermetic seal leak detection apparatus for testing hermetically sealed containers and devices for leaks without the need to create a custom or specially manufactured testing chamber conforming to the dimensions of the specific object under test. The size of the testing chamber may be mechanically adjusted by the novel use of bellows to reduce and optimize the amount of gas space in a test chamber which surrounds the hermetically sealed object under test. The present invention allows the size of the test chamber to be selectively adjusted during testing to provide an optimum test chamber gas space. The present invention may be further adapted to isolate and test specific portions of the hermetically sealed object under test for leaks.

Claims

1. A hermetic seal leak detection apparatus comprised of:

a hermetically sealed object under test wherein said hermetically sealed object under test has an internal test object pressure;

at least one variable size gas space test chamber enclosed in a flexible housing which surrounds said hermetically sealed object under test, wherein said variable size gas space test chamber has a measurable test chamber pressure;

at least one expandable and contractible bellows operatively coupled with said variable size gas space test chamber;

wherein said at least one expandable and contractible bellows controls size of said variable size gas space chamber by movement of said bellows alternatively causing said test chamber pressure to be unequal to said internal test object pressure; and

at least one sensing device operatively coupled with said variable size gas space chamber to sense changes in said test chamber pressure over a specified time duration wherein said internal test object pressure and said test chamber pressure are identified by readings of said sensing device producing values that define a pressure value curve which indicates the presence or absence of a leak in said hermetically sealed object under test.

2. The apparatus of claim 1 wherein said measurable test chamber pressure is selected from a group consisting of gas pressure, negative gas pressure and gas density.

3. The apparatus of claim 1 wherein the size of said variable size gas space test chamber is selectively compressed to correspond to a size of the hermetically sealed object under test to produce an optimized gas space in said hermetically sealed object under test.

4. The apparatus of claim 1 wherein said flexible housing surrounding said variable size gas space test chamber is comprised of said at least one expandable and contractible bellows.

5. The apparatus of claim 1 which further includes at least one sealing component selected from a group consisting of epoxy, gasket, o-rings, glue, a non-movable plate, a movable plate, a welded joint, a plunger, a contoured component, a geometrically interlocking component, a viscious material, a chamber cap and a magnetic interface, wherein said sealing component is used to seal said variable size gas space test chamber.

6. The apparatus of claim 1 wherein said variable size gas space chamber includes at least one partition placed within a gas space of said variable size gas space test chamber to reduce said gas space space of said chamber.

7. The apparatus of claim 6 wherein said at least one partition is comprised of a non-permeable material placed within said variable size gas space test chamber.

8. The apparatus of claim 6 wherein said at least one partition is placed inside said variable size gas space test chamber to form an upper gas chamber and a lower gas chamber within said variable size gas space test chamber.

9. The apparatus of claim 8 wherein said at least one expandable and contractible bellows comprises a first bellows and a second bellows, and said at least one variable size gas space test chamber comprises a first variable size gas space test chamber and a second variable size gas space test chamber wherein said first variable size gas space test chamber has a first variable gas space size dependent on a position of said first bellows along a lateral axis of movement and said second variable size gas space test chamber has a second variable gas space size dependent on a position of said second bellows along the lateral axis of movement.

10. The apparatus of claim 8 wherein said upper gas chamber has a first variable gas space pressure and said lower gas chamber has a second variable gas space pressure, and further wherein said first variable gas space pressure is different from said lower gas space pressure.

11. The apparatus of claim 10 wherein said at least one sensing device comprises a plurality of sensing devices, and said variable size gas space test chamber is operatively coupled with said plurality of sensing devices wherein said plurality of sensing devices repeatedly measure changes in gas states selected from a group consisting of gas pressure, gas density and gas composition.

12. The apparatus of claim 8 wherein said upper gas chamber and said lower gas chamber are operatively and independently coupled to a vacuum inducing device capable of changing a volume of a gas space within said upper gas chamber and said lower gas chamber.

13. The apparatus of claim 8 wherein said upper gas chamber and said lower gas chamber are operatively and independently coupled to a pressure inducing device capable of changing a pressure of a gas space within said upper gas chamber and said lower gas chamber.

14. The apparatus of claim 6 wherein said at least one partition is an o-ring.

15. The apparatus of claim 14 wherein said at least one variable size gas space test chamber comprises a plurality of variable size gas space test chambers, and further wherein each of said plurality of variable size gas space test chambers has a gas space pressure that is independent of a variable gas space pressure of rest of said plurality of variable size gas space test chambers.

16. The apparatus of claim 6 which further includes a plurality of spaced partitions to form two or more variable size space gas test chambers.

17. The apparatus of claim 16 wherein each of said two or more variable size gas space test chambers has a gas space pressure that is independently used for testing a portion of said hermetically sealed object under test.

18. The apparatus of claim 1 wherein said at least one expandable and contractible bellows has a ripple diaphragm configuration.

19. The apparatus of claim 1 wherein said at least one expandable and contractible bellows has dimensions ranging from ⅛

-inch to 54-inches.

20. The apparatus of claim 1 wherein said at least one expandable and contractible bellows is non-cylindrical.