Method and apparatus for detecting leaks in a sealed container
AssigneeThe Mead Corporation
InventorThomas M. Potteiger
Life of this patent
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Abstract
A method is disclosed for testing the integrity of a container of the type which includes a thin walled cup and a flexible lid sealed to the rim of the cup. In accordance with the method a force is applied to an elongated portion of the lid which circumscribes an area which is coaxial with the center of the cup. Since the cup is sealed this application of force causes the circumscribed area to bow outwardly from the cup. The displacement of the bowed portion is then compared to the previously measured displacement for containers known to be of acceptable quality. An apparatus for performing the test has an upper test assembly with a rim which is adapted to be urged against the elongated portion of the lid. A displacement sensor is mounted within the upper test assembly.
Claims19
The method of testing the integrity of a container comprising a thin walled cup having a rim portion defining a mouth thereof and a flexible lid sealed to said rim portion, said container enclosing a volume of filler material and a volume of head space, said method comprising the steps of:
- applying a force to an elongated edge portion of the lid which circumscribes a central portion of the lid which is coaxial with the center of the cup thereby causing said lid to bow outwardly from the cup;
- measuring the position of the bowed portion of the lid by means which apply no substantial force to said bowed portion;
- comparing the position of the lid with a first predetermined acceptable position value.
Apparatus for testing the integrity of a container of a type comprising a thin-walled cup having a rim portion defining a mouth of the cup and a flexible lid sealed to the rim portion, which container is adapted for enclosing a volume of filler material and a volume of head space, said apparatus comprising:
- means for holding the container in an upright position during testing;
- an upper test assembly including, a pressure edge adapted for contacting the lid of the cup and circumscribing a central portion of the lid coaxial with the cup and inside the rim portion, and a displacement measuring transducer mounted in said upper test assembly and adapted for measuring changes in position of the cup lid without applying any substantial force to the cup lid;
- a force generator operatively connected to said test assembly for urging it against the cup lid;
- and
- computer means connected to the measuring means for comparing the displacement of the cup lid when the upper test assembly is urged against it by said force means with a predetermined acceptable displacement value.
Dependencies are inferred from the claim text.