Patent ID: 8202076
Filing Date: 2012-06-19
Classification: B29C,B29L

Abstract:
1. Apparatus comprising a punch arrangement and a die arrangement having a cavity, said punch arrangement and said die arrangement being opposite one another for compression moulding a preform from a dose of plastics, a punch being included in said punch arrangement, said apparatus further comprising two mutually movable parts each having a forming surface for forming undercuts on a neck portion of said preform, wherein said punch arrangement further comprises an annular forming element distinct from said mutually movable parts, and from said punch, said annular forming element having an annular forming surface for being contacted by the plastics and thereby forming an annular edge zone of said preform, said apparatus further comprising a retaining sleeve distinct from said annular forming element, said retaining sleeve having a conical internal retaining surface for engaging with a coupling surface of the movable parts in order to keep the movable parts in contact with one another in a contact position thereof, said punch arrangement and said die arrangement being mutually movable to define a closed forming chamber delimited by said die arrangement, said punch, said mutually movable parts and said annular forming element, wherein said annular forming element and said punch are movable relative to one another after the forming chamber has been closed in order to progressively reduce volume of said forming chamber until said preform is obtained, and wherein each movable part has a guiding surface which is slidable in contact with an external guiding surface of said annular forming element when the movable parts are in the contact position and move relative to the annular forming element in order to close or open the forming chamber.