Apparatus for preventing thermal damage to a preformed plug during molding of a housing therearound
Patent 4488573 Issued on December 18, 1984. Estimated Expiration Date: 
July 13, 2003. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
July 13, 2003. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3094376 3202749 3807692 Methods for making molded plug and plug valve Rotary ball valve having seating rings Patent #: 4257575 InventorsAssigneeApplicationNo. 06/513445 filed on 07/13/1983US Classes:137/375, Jacketed251/315.05, Nonmetallic251/315.15Having inseparable headExaminersPrimary: Schwadron, Martin P.Assistant: Shay, James R. Attorney, Agent or FirmInternational ClassesB29C 45/14 (20060101)F16K 27/06 (20060101) AbstractA rotary plug valve which is of the type comprising a housing formed of a polymer and a rotary plug disposed in a through-passage of the housing. The plug is formed of a polymer and includes a bore selectively alignable with the through-passage to admit the passage of fluid. The plug valve is formed by forming the plug and attaching thereto a preformed polymeric shield by snap-fitting the shield onto the plug. The shield has an inner surface conforming to the periphery of the plug. The plug and shield assembly is positioned within a cavity of a mold. The cavity corresponds to the shape of the housing. A molten polymer is introduced into the cavity and intimately contacts the shield and forms the housing around the plug. | |
