Mold part guide mechanism

A mold for forming molded products, said mold comprising:

• at least three mold parts, at least one of said at least three mold parts moveable along a mold movement direction with respect to at least one of the others of said at least three mold parts;
• a guide mechanism for guiding said at least one moveable mold part into and out of a mold forming position along said mold movement direction in conjunction with the at least two other mold parts, wherein said guide mechanism comprises:
• a first structure fixed to one of said at least two other mold parts;
• a second structure fixed to said at least one moveable mold part, wherein one of said first and second structures sandwiches at least a portion of the other of said first and second structures;
• and
• a plurality of bearings separating said first and second structures and permitting movement in said mold movement direction;
• at least one spring applying a preload pressure to said bearings in at least one direction normal to said mold movement direction:
• a return spring for biasing said at least one moveable mold part in one of said directions towards and away from said mold forming position;
• and
• a cam for moving said at least one moveable mold part, in opposition to said return spring bias, to the other of said directions away from or towards said mold forming position.

A mold for forming injection molded products, said mold comprising:

• a lower mold half;
• an upper mold half, one of said upper and lower mold halves moveable with respect to the other of said upper and lower mold halves;
• a moveable bottom end plug moveable along a mold movement direction with respect to at least one of said upper mold half and said lower mold half;
• a guide mechanism for guiding said bottom end plug into and out of a mold forming position along said mold movement direction in conjunction with the upper and lower mold halves, wherein said guide mechanism comprises:
• a first structure fixed to one of said upper and lower mold halves;
• a second structure fixed to said bottom end plug, wherein one of said first and second structures has two portions, said two portions sandwiches at least one portion of the other of said first and second structures;
• and
• a plurality of bearings separating said first and second structures and permitting movement of said bottom end plug in said mold movement direction;
• and
• at least one spring applying a preload pressure to said bearings in at least one direction normal to said mold movement direction:
• a return spring for biasing said bottom end plug in one of said directions towards and away from said mold forming position;
• and
• a cam, operated in response to movement of one of said upper and lower mold halves, for moving said at least one moveable mold part, in opposition to said return spring bias, to the other of said directions away from or towards said mold forming position.

A mold for forming molded products, said mold comprising:

• a lower mold half;
• an upper mold half, one of said upper and lower mold halves moveable with respect to the other of said upper and lower mold halves;
• a split bottom end plug having separate upper and lower portions moveable with respect to each other, said upper and lower portions moveable along respective mold movement directions toward said upper mold half and said lower portion, respectively;
• each of said upper and lower end plug portions having a guide mechanism, said guide mechanism for guiding a respective bottom end plug portion into and out of a mold forming position along said respective mold movement directions in conjunction with the upper and lower mold halves, wherein each said guide mechanism comprises:
• a first structure fixed to said corresponding mold half;
• a second structure fixed to said corresponding bottom end plug portion, wherein one of said first and second structures has two portions, said two portions sandwiches at least one portion of the other of said first and second structures;
• and
• a plurality of bearings separating said first and second structures and permitting movement of said corresponding bottom end plug portion in said respective mold movement directions;
• and
• at least one spring applying a preload pressure to said bearings in at least one direction normal to said respective mold movement direction:
• a return spring for biasing said corresponding bottom end plug portion in one of said directions towards and away from said mold forming position;
• and
• one of a tab and receptacle on said upper portion for engagement with a corresponding one of a receptacle and tab on said lower portion, said engagement occurring prior to meeting of said portions during closure of said mold halves;
• and
• a cam, operated in response to movement of one of said upper and lower mold halves and after said tab engages with said receptacle, for moving said corresponding bottom end plug portion, in opposition to said return spring bias, to the other of said directions away from or towards said mold forming position.