GUARNIZIONE DI TIPO 0-RING STAMPATA SENZA SBAVATURE

• Main Authors: JAMES F. WALDER, TERRY T. THRELFALL
• Format: Patent
• Language: Italian
• Published: 02.03.1989
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULARARTICLES; INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS; PERFORMING OPERATIONS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

PURPOSE: To provide a superior seal along inside and outside diameters of an O-ring and reduce rejection in automatic loading machines by disposing a sprue off a parting line of a mold and injecting a thermosetting material from the sprue so disposed for molding an O-ring. CONSTITUTION: In transfer molding an O-ring, an uncured rubber material 30 is loaded in a pot formed after a mold is closed by top portions of a top mold half 10 and a top fixed side mold plate 16 and a top plate 28. The uncured rubber material 30 is pressed by a ram 32 so as to be moved into a mold cavity 20 through a sprue hole 26. The movement of the ram 32 and closure of the mold are carried out by virtue of hydraulic pressure. The sprue hole 26 is disposed off a parting line 22. Preferably, the sprue hole 26 is between about 15 to 90 degrees off the parting line, more preferably between about 30 to 90 degrees and most preferably between about 45 to 90 degrees. In addition, it is desirable that the sprue hole is provided within in the top mold half 10.