Cut-off process for terminating injection operations of an injection molding machine

• US 4,568,508 A
• Filed: 07/29/1983
• Issued: 02/04/1986
• Est. Priority Date: 09/17/1982
• Status: Expired due to Fees

• Current Assignee: Salzgitter Klöckner-Werke GmbH (Salzgitter AG)
• Original Assignee: Salzgitter Klöckner-Werke GmbH (Salzgitter AG)
• Inventors: Diekmann, Herbert, Roseland, Hermann
• Primary Examiner(s): Woo, Jay H.
• Assistant Examiner(s): Woodard, Joye L.
• Application Number:
  US06/518,631
• Time in Patent Office: 921 Days
• Field of Search: 264/40.1, 264/40.4, 264/40.5, 264/328.8, 264/308, 425/135, 425/136, 425/560, 425/147, 425/137, 425/139, 425/562, 425/149, 425/563, 425/146
• US Class Current: 264/328.8
• CPC Class Codes: B29C 45/7613 the termination of flow of material into the mould
• CPC Class Codes: B29D 35/082 injecting first the outer sole part

Abstract

A cut-off process for an injection molding machine for forming two-layer, directly laminated footwear soles and includes a pressure transmission pin which is guided in a passageway constructed as a through-hole between the mold cavity and the outer surface of the mold. The pressure transmission pin is preloaded by a spring in the direction of the mold cavity so that it can be depressed or actuated under injection pressure. When the injection pressure is relieved and the molded piece shrinks, the pressure transmission pin will be moved back by the spring to its initial position, thereby releasing a switch for a new switching operation for the next, second, injecting operation.

Claims

1. A cut-off process for an injection molding machine molding an overlying double layer directly laminated mold piece under pressure within a mold having a mold cavity, said mold cavity having a first mold wall for a first injection mass injected into said cavity, said first mass defining a second mold wall for a second injection mass injected into said cavity over said first mass, and a passageway formed between said first mold wall and an outer surface portion of said mold, comprising in combination:

disposing a pressure transmission pin, having a head, in said passageway for movement inwardly toward and outwardly away from said cavity respectively between first and second positions;

initially extending said head inwardly of said first mold wall in said first position prior to injection of said first mass;

spring biasing said pin into said first position;

moving said pin into said second position in response to injection pressure of said first injection mass;

again extending said head inwardly of said first mold wall by spring biasing said pin back into said first position upon a reduction of said injection pressure due to the shrinkage of said first injection mass;

again moving said pin into said second position in response to injection pressure of said second injection mass as transferred through said first mass; and

switching off first and second injection operations respectively for said first and second mass only as said pin moves into said second positions.