Mold opening device

A mold structure, comprising:

• first, second and third mold parts stacked one on top of the other, each having first means thereon defining at least a part of a mold cavity, said second part being oriented between said first and third parts and having said first means on both sides thereof;
• support means for supporting said first mold part for movement toward and away from said third mold part;
• an elongate tie rod extending between said first and third mold parts and through an opening in said second mold part, said tie rod being supported on said first mold part by first mounting means, said tie rod having first locking means thereon at a location spaced from said first mold part;
• second locking means provided on said third mold part and cooperable with said first locking means on said tie rod for preventing lengthwise movement of said tie rod relative to said third mold part, said second locking means including second means defining an opening through said third mold part axially aligned with said tie rod;
• stop means secured to said second mold part and positioned to operatively engage said first locking means for limiting the spacing between said first and second mold parts to a prescribed spacing so that as said first mold part and said tie rod secured thereto are moved away from said third mold part, said first locking means on said tie rod will engage said stop means to effect a movement of said second mold part away from said third mold part;
• and
• extendible drive means axially aligned with said tie rod and receivable in said opening for engaging said tie rod to effect a movement of said first mold part and said tie rod away from said third mold part.