Apparatus and method for sealing a lid onto a container

摘要

A modular type replaceable heating unit with a downwardly facing heating ring for use in an apparatus for sealing a flat lid with a lower layer of heat bondable material onto the upper, generally flat surface of a flange extending around the periphery of an access opening in a container. The apparatus moves the heating unit between first and second positions. The apparatus includes a generally fixed high frequency power supply for energizing the heating ring, connecting the high frequency power supply to the heating ring only while the heating unit is moving between the first and second positions. The ring is forced against the lid as the power supply is energized and is released from the lid after the power supply has been de-energized. Preferably the ring is an inductor. A plurality of these heating units is carried by a turret to define individual heating stations on the turret which stations rotate to selectively energize the individual heating units. The heating units include means for coupling with the moving means of the apparatus and a transformer for energizing the heating ring.