Tamper evident container and related apparatus

DETAILED DESCRIPTION This invention relates to improved tamper evident container constructions including apparatus for forming such containers.
It has become increasingly important to provide tamper proof or tamper evident packaging for consumer related goods and particularly for medicinal products and foodstuffs.
Recent history documents the tragic consequences which can occur when tampering with container contents goes unnoticed.
It is, in fact, now required by law that at least certain pharmaceutical products be protected by in tamper proof packaging.
The practical necessity for tamper proof or tamper evident packaging for non-medicinal products and particularly for packaged food items such as ice cream and other dairy products, as well as many other pre-prepared food products is readily apparent.
Numerous attempts have been made in the container industry and specifically with respect to consumer oriented foodstuffs, medicines, etc.
to prevent potentially harmful tampering with the contents of such containers.
It is well known, for example, to heat seal a thin foil disk about the container opening prior to application of the lid.
This approach, while successful to a large extent, nevertheless involves the addition of another component to the assembly, i.
e.
, the foil disk, and related assembly procedures and associated costs.
Other attempts to provide effective tamper proof mechanisms in container assemblies are well documented in the patent literature.
U.
S.
Pat.
No.
4,966,294, for example, discloses a tamper evident closure for a wide mouth container wherein rim segments are formed in the skirt portion of the container lid and are arranged so that upward lifting force applied against the lid flange will cause breakage to occur at opposite ends of the flange, and a continued upward pulling on the flange will results in a pair of tear lines in the lid to facilitate removal of the lid.
In U.
S.
Pat.
No.
2,383,760, a closure for a container includes a flat upper surface in the peripheral depending skirt portion, around which is adhesively secured a strip which extends below the container flange and includes a bent marginal flange portion extending upwardly and inwardly from the bend