Abstract: An apparatus and method for forming a lid having an annular mounting portion, an annular trough region positioned radially inward of the annular mounting portion, an annular side wall extending upwardly from an inner periphery of the annular trough region to an annular ridge adjacent said annular side wall, and a crown region is set forth. The apparatus includes a forming die having an upper surface of a configuration conforming to the configuration of the lid, a forming ring for aiding in the forming of the lid, a positioning device for positioning the thermoformable sheet material adjacent the upper surface of the forming die between the forming die and the forming ring and a drive mechanism for lowering the forming ring into contact with the sheet material. The method includes contacting that portion of the sheet material which forms a lowermost region of the lid with the forming ring so as to carry the material down into the lowermost region of the forming die.

Abstract: An apparatus and method for forming a lid having an annular mounting portion, an annular trough region positioned radially inward of the annular mounting portion, an annular side wall extending upwardly from an inner periphery of the annular trough region to an annular ridge adjacent said annular side wall, and a crown region is set forth. The apparatus includes a forming die having an upper surface of a configuration conforming to the configuration of the lid, a forming ring for aiding in the forming of the lid, a positioning device for positioning the thermoformable sheet material adjacent the upper surface of the forming die between the forming die and the forming ring and a drive mechanism for lowering the forming ring into contact with the sheet material. The method includes contacting that portion of the sheet material which forms a lowermost region of the lid with the forming ring so as to carry the material down into the lowermost region of the forming die.