Apparatus for preventing thermal damage to a preformed plug during molding of a housing therearound
First Claim
1. A ball valve assembly suitable for use in a molding operation wherein molten polymeric material is introduced into a mold cavity around said ball assembly to produce a formed-in-place housing around said ball assembly, said ball assembly including a bore which is rotatably alignable with a through-passage of the housing to admit a flow of fluid, the improvement wherein said ball assembly includes a ball element of a polymer, said bore being formed in said ball element, and a shield of a polymeric material is attached to said ball element by a snap-lock fit which maintains an inner spherical surface of said shield against a correspondingly shaped outer spherical surface of said ball.
0 Assignments
0 Petitions
Accused Products
Abstract
A 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.
-
Citations
9 Claims
- 1. A ball valve assembly suitable for use in a molding operation wherein molten polymeric material is introduced into a mold cavity around said ball assembly to produce a formed-in-place housing around said ball assembly, said ball assembly including a bore which is rotatably alignable with a through-passage of the housing to admit a flow of fluid, the improvement wherein said ball assembly includes a ball element of a polymer, said bore being formed in said ball element, and a shield of a polymeric material is attached to said ball element by a snap-lock fit which maintains an inner spherical surface of said shield against a correspondingly shaped outer spherical surface of said ball.
- 7. A molded plastic valve comprising a rotary molded polymeric plug having a bore therethrough, a housing having a through-passage therethrough, said plug being disposed in said housing and said bore being alignable with said passage by rotational movement of said plug, a shield bonded to said housing and disposed between said plug and housing, said shield having a snap-lock fit with said ball.
Specification