US Patent 7464428 Sole elements of varying density and methods of manufacture

The invention relates to sole elements and methods for manufacturing sole elements for shoes, in particular for sport shoes, with a specific density distribution in a transverse and/or longitudinal direction. The methods include the steps of manufacturing a sole element preform from a polymer material with a thickness varying in the transverse and/or longitudinal direction depending on the desired density distribution and the press-forming of the sole element preform in a forming tool to form the finished sole element from the sole element preform.