Method for making a shaft seal
AssigneeGarlock Inc.
InventorDean R. Bainard
Life of this patent
Estimating the term…
Abstract
A method for making a shaft seal of the type including an elastomeric body and a polytetrafluoroethylene sealing element comprising inserting a metal shell (if employed in the seal), a synthetic rubber blank prep form and a polytetrafluoroethylene sealing element into a transfer or compression mold, and then closing the mold to simultaneously form a sealing lip portion of the polytetrafluoroethylene sealing element into the desired shape, mold the rubber into the desired shape and bond the rubber to the shell (if used) and to the anchor portion of the polytetrafluoroethylene sealing element.
Claims31
A method for making, by transfer molding, an annular shaft seal of the type including an annular ring molded from synthetic rubber and a polytetrafluoroethylene sealing element including a radial anchor portion connected to said ring and a frustoconical sealing lip spaced-away from said ring, said method comprising:
- (a) providing a transfer mold including lower mold cavity section and a separate, relatively movable upper mold cavity section, said lower and upper sections defining a mold cavity therebetween, said upper mold cavity section having an upper recess for receiving a blank prep form of synthetic rubber and an opening communicating between said recess and said cavity, and a movable ram located above said upper mold cavity section for causing synthetic rubber to flow from said recess into said cavity;
- (b) inserting a sintered polytetrafluoroethylene member into said mold cavity;
- (c) inserting a synthetic rubber blank prep into said recess;
- and
- (d) closing the mold to simultaneously move both said upper mold cavity section, said ram, and said lower section toward each other, said upper section contacting said polytetrafluoroethylene member and forming a portion of said polytetrafluoroethylene member between said upper section and said lower section into a polytetrafluoroethylene sealing element having a radial anchor portion and a substantially homogeneous, formed, frustoconical sealing lip, and said ram contacting said blank prep form between said ram and said upper section and flowing said blank prep form into said cavity on top of and into contact with said anchor portion of said polytetrafluoroethylene sealing element to mold said blank prep form into an annular synthetic rubber ring in contact with said anchor portion and spaced away from and out of contact with said sealing lip, and
- (e) bonding said molded ring to said anchor portion only of said polytetrafluoroethylene sealing element.
A method for making an annular shaft seal of the type including an annular elastomeric body and an annular, flexible, non-elastomeric sealing element having a radial anchor portion and having a frustoconical sealing lip, with said elastomeric body being bonded to said anchor portion and being spaced away from and out of contact with said sealing lip, said method comprising:
- (a) inserting a flexible, non-elastomeric member and a blank prep form of elastomer in a mold,
- (b) closing said mold, simultaneously forming said member into a sealing element having a radial anchor portion and a substantially homogeneous, die-formed, frustoconical, sealing lip and flowing said blank prep form of elastomer into an annular elastomeric body spaced away from and out of contact with said sealing lip and in contact with said anchor portion, and
- (c) bonding said elastomeric body to said radial anchor portion only of said sealing element.
A method for making, by compression molding, an annular shaft seal of the type including an annular ring molded from synthetic rubber and a polytetrafluoroethylene sealing element including a radial anchor portion connected to said ring and a frustoconical sealing lip spaced-away from said ring, said method comprising:
- (a) providing a compression mold including a lower mold cavity section and an upper mold cavity section, all defining a mold cavity therebetween,
- (b) inserting a sintered polytetrafluoroethylene member into said mold cavity;
- (c) inserting a synthetic rubber blank prep form into said cavity on top of said member, and
- (d) closing the mold to simultaneously move said upper mold cavity section and said lower section toward each other, said upper section contacting said member and forming a portion of said polytetrafluoroethylene member between said upper section and said lower section into a polytetrafluoroethylene sealing element having a radial anchor portion and a substantially homogeneous, formed, frustoconical sealing lip, and said upper portion also contacting said blank prep form and molding it between said upper and lower sections into an annular synthetic rubber ring on top of and in contact with said anchor portion of said polytetrafluoroethylene sealing element and spaced away from and out of contact with said sealing lip, and
- (e) bonding said molded ring to said anchor portion only of said polytetrafluoroethylene sealing element.
A method for making, by transfer molding, an annular shaft seal of the type including an annular ring molded from synthetic rubber and a polytetrafluoroethylene sealing element including a radial anchor portion connected to said ring and a frustoconical sealing lip spaced-away from said ring, said method comprising:
- (a) providing a transfer mold including a lower mold cavity section, a separate, relatively movable upper mold cavity section and a center ring, said lower and upper sections defining a mold cavity therebetween, said upper mold cavity section having an upper recess for receiving a blank prep form of synthetic rubber and an opening communicating between said recess and said cavity whereby synthetic rubber can flow from said recess into said cavity,
- (b) inserting a sintered polytetrafluoroethylene member into said mold cavity,
- (c) inserting a synthetic rubber blank prep form into said recess, and
- (d) closing the mold to simultaneously move both said upper mold cavity section, said ram, and said lower section toward each other, said upper section contacting said polytetrafluoroethylene member and forming a portion of said polytetrafluoroethylene member between said upper section and said lower section into a polytetrafluoroethylene sealing element having a radial anchor portion and a substantially homogeneous, formed, frustoconical sealing lip, and said ram contacting said blank prep form between said ram and said upper section and flowing said blank prep form into said cavity on top of and into contact with said anchor portion of said polytetrafluoroethylene sealing element to mold said blank prep form into an annular synthetic rubber ring in contact with said anchor portion and spaced away from and out of contact with said sealing lip, and
- (e) bonding said molded ring to said anchor portion only of said polytetrafluoroethylene sealing element.
A method for making, by compression molding, an annular shaft seal of the type including an annular ring molded from synthetic rubber and a polytetrafluoroethylene sealing element including a radial anchor portion connected to said ring and a frustoconical sealing lip spaced-away from said ring, said method comprising:
- (a) providing a compression mold including a lower mold cavity section, an upper mold cavity section and a center ring, said lower and upper sections defining a mold cavity therebetween;
- (b) inserting a sintered polytetrafluoroethylene member into said mold cavity,
- (c) inserting a synthetic rubber blank prep form into said recess,
- (d) closing the mold to simultaneously move said upper mold cavity section and said lower section toward each other, said upper section contacting said member and forming a portion of said polytetrafluoroethylene member between said upper section and said lower section into a polytetrafluoroethylene sealing element having a radial anchor portion and a substantially homogeneous, formed, frustoconical sealing lip, and said upper portion also contacting said blank prep form and molding it between said upper and lower sections into an annular synthetic rubber ring on top of and in contact with said anchor portion of said polytetrafluoroethylene sealing element and spaced away from and out of contact with said sealing lip, and
- (e) bonding said molded ring to said anchor portion only of said polytetrafluoroethylene sealing element.
Dependencies are inferred from the claim text.