PROCEDIMIENTO PARA LA FABRICACION DE PIEZAS DE PLASTICO, ES-PECIALMENTE PATILLAS PARA GAFAS

摘要

In the manufacture of eyeglass bows, a metal core (2) is placed in a mold (1) and is gripped at one end (3) before the mold (1) is filled with plastic material. To ensure that the metal core (2) can be held in position in the mold (1) as the plastic charge enters, the metal core (2) at that end thereof which is opposite to its gripped end (3) is joined to a tensile element (6), which extends out of the mold. The joint between the tensile element (6) and the metal core (2) forms a rated breaking point having a limited ultimate tensile strength. Before the mold (1) has been completely filled with plastic charge, a tensile stress in excess of the ultimate tensile strength of the joint is applied to the latter by the tensile element (6) so that the tensile element will be severed and pulled out of the mold (1).