Molding devices and process for making a molded plastic lens mount

A molding device for forming a molded plastic lens mount having an uncentered lens element insert molded and centered therein such that the optical axis of the uncentered lens element coincides with a geometrical axis of the mount, the mount being of the type including integrally molded means for retaining the uncentered lens element by the periphery thereof and a cylindrical wall having an axially disposed helical screw thread integrally molded on the exterior surface thereof for coupling the lens mount to another lens mount having a complementary screw thread thereon, said molding device comprising:

• a cavity mold including first and second mold sections movable relative to one another between an open position and a closed position wherein said first and second mold sections are aligned, on a common geometrical axis of said mold, in abutting relation, said first and second mold sections including cooperating means therein for defining an internal cavity within said closed mold into which plastic may be injected to form the mount, said cavity being complementary in shape to the shape of the molded plastic mount and being disposed within said closed mold such that the geometrical axis of the mount coincides with said geometrical axis of said mold;
• said means for defining said cavity including first and second opposed zonal clamps mounted on said geometrical axis of said mold, said first and second zonal clamps including low friction rings on their respective opposed ends for engaging opposite optical surfaces of the uncentered lens element, said first zonal clamp being mounted for axial displacement towards said second zonal clamp, when said mold is in said closed position and prior to the injection of the plastic, for causing said low friction rings to exert a compressive force on the uncentered lens element thereby displacing the uncentered lens element in directions transverse to said geometrical axis of said mold until the optical axis of the uncentered lens element is coincident with said mold and said second zonal clamp being mounted for both axial rotation and displacement to facilitate release of the molded plastic mount from said mold subsequent to the forming of the mount and when said first and second mold sections are in said open position;
• said means defining said cavity including surfaces within said closed mold which form the retaining means around the periphery of the uncentered lens element held by said zonal clamps for retaining the uncentered lens element in the mount, and surfaces which form the cylindrical wall and the helical screw thread thereon, when plastic is injected into the mount, said surface for forming the helical thread being in said second mold section;
• and
• means on said second zonal clamp for holding the molded plastic mount subsequent to the injection of plastic such that the molded mount rotates with said second zonal clamp and relative to said second mold section to disengage the molded mount from said surface forming the helical screw thread.

A molding device for forming a molded plastic lens mount having an uncentered lens element insert molded and centered therein such that the optical axis of the lens element coincides with a geometrical axis of the mount, the mount being of the type including integrally molded means for retaining the uncentered element in the mount and at least one access opening through which a between-the-lens shutter and/or aperture defining mechanism may extend, in operative relation with the insert molded lens element, for movement in directions transverse to the geometrical axis of the mount, said molding device comprising:

• a cavity mold including first and second mold sections movable relative to one another between an open position and a closed position wherein said first and second mold sections are aligned on a common geometrical axis of said mold in abutting relation, said first and second mold sections including cooperating means therein for defining an internal cavity within said closed mold into which plastic may be injected to form the mount, said cavity being complementary in shape to the shape of the molded plastic mount and being disposed within said closed mold such that the geometrical axis of the mount coincides with said geometrical axis of the mold;
• said means for defining said cavity including first and second opposed zonal clamps mounted on said geometrical axis of said mold, for engaging and centering the uncentered lens element on said geometrical axis of said mold, said first and second zonal clamps including low friction rings on their respective opposed ends for engaging opposite optical surfaces of the uncentered lens element, at least one of said zonal clamps being mounted for rotational displacement and also for axial displacement toward said other zonal clamp, when said first and second mold sections are located in said closed position, for causing said low friction annular rings to exert a compressive force on the uncentered lens element, thereby displacing the uncentered lens element in directions transverse to said geometrical axis of said mold until the optical axis of the uncentered lens element is coincident with said geometrical axis of said mold;
• said means defining said cavity including surfaces therein which form the retaining means around the periphery of the lens element held by said zonal clamps, when plastic is injected into said mold, for retaining the lens element in the mount;
• and
• said means defining said cavity further including opposed surfaces that are in contacting relation within the bounds of said cavity, when said mold is closed, for selectively blocking the flow of plastic into predetermined portions of said cavity, thereby forming said at least one access opening in said molded mount, said access opening being formed in said mount in a configuration to allow a shutter and/or aperture defining mechanism to extend therethrough, in operative relation to the insert molded lens element, for movement in directions transverse to the geometrical axis of the mount.

A method of forming a molded plastic lens mount having an uncentered lens element insert molded and centered therein such that the optical axis of said uncentered lens element coincides with a geometrical axis of said mount, said mount being of the type including retaining means molded around the periphery of said uncentered lens element for retaining said uncentered element in said mount and a cylindrical wall having an axially disposed screw thread integrally molded therewith for coupling said lens mount to another lens mount having a complementary screw thread thereon, said method comprising the steps of:

• providing a cavity mold including first and second mold sections movable relative to one another between an open position and a closed position wherein said first and second mold sections are aligned, on a common geometrical axis of said mold, in abutting relation, said first and second mold sections including cooperating means therein for defining an internal cavity within said closed mold into which plastic may be injected to form said mount, said cavity defining means including first and second opposed zonal clamps mounted on said geometrical axis of said mold, said first and second zonal clamps including low friction rings on their respective opposed ends for engaging opposite surfaces of said uncentered lens element, said first zonal clamp being mounted for axial displacement relative to said first mold section and said second zonal clamp being mounted for both axial rotation and displacment relative to said second mold section;
• with said first and second mold sections located in said open position, placing said uncentered lens element on said low friction ring of said second zonal clamp;
• moving said first and second mold sections to the closed position;
• axially displacing said first zonal clamp toward said second zonal clamp such that said low friction rings thereon engage the opposite optical surfaces of said uncentered lens element and exert a compressive pressure thereon thereby displacing said uncentered lens element in directions transverse to said geometrical axis of said mold until the optical axis of said uncentered lens element is coincident with said geometrical axis of said mount;
• injecting plastic into said cavity of said closed mold to form said molded plastic mount around the periphery of said lens element held by said first and second zonal clamps;
• moving said first and second mold sections to said open position;
• and
• axially rotating and displacing said second zonal clamp to disengage said molded mount and a surface in said mold for forming the helical screw thread on the cylindrical wall of the molded mount to facilitate the release of the molded mount from said mold.

A method of forming a molded plastic lens mount having an uncentered lens element insert molded and centered therein such that the optical axis of said uncentered lens element coincides with a geometrical axis of said mount, said mount being of the type including retaining means molded around the periphery of said uncentered lens element for retaining said uncentered element in said mount and a cylindrical wall having an axially disposed screw thread integrally molded on an exterior surface thereof for coupling said lens mount to another lens mount having a complementary screw thread thereon, said method comprising the steps of:

• providing a cavity mold including first and second mold sections movable relative to one another between an open position and a closed position wherein said first and second mold sections are aligned, on a common geometrical axis of said mold, in abutting relation, said first and second mold sections including cooperating means therein for defining an internal cavity within said closed mold into which plastic may be injected to form said mount, said cavity defining means including an appropriately shaped surface in said second mold section for forming said helical screw thread, and first and second opposed zonal clamps mounted on said geometrical axis of said mold, said first and second zonal clamps including low friction rings on their respective opposed ends for engaging opposite surfaces of said uncentered lens element, said first zonal clamp being mounted for axial displacement relative to said first mold section and said second zonal clamp being mounted for both axial rotation and displacement relative to said second mold section;
• with said first and second mold sections located in said open position, placing said uncentered lens element on said low friction ring of said second zonal clamp;
• moving said first and second mold sections to the closed position;
• axially displacing said first zonal clamp toward said second zonal clamp such that said low friction rings thereon engage the opposite optical surfaces of said uncentered lens element and exert a compressive pressure thereon thereby displacing said uncentered lens element in directions transverse to said geometrical axis of said mold until the optical axis of said uncentered lens element is coincident with said geometrical axis of said mount;
• injecting plastic into said cavity of said closed mold to form said molded plastic mount around the periphery of said lens element held by said first and second zonal clamps;
• moving said first and second mold sections to said open position;
• and
• while holding the molded mount with means on the second zonal clamp, axially rotating and displacing said second zonal clamp to disengage said molded mount and the surface in said mold for forming the helical screw thread on the cylindrical wall of the molded mount to facilitate the release of the molded mount from said mold.