Rotary ball lock

In combination with a mold having two mold parts movable between an open position remote from each other and a closed position sealingly contacting each other, a mold locking mechanism for securely clamping said parts together in said closed position comprising:

• a cylindrical tie rod extending between said mold parts and supported on one said mold part by first mounting means, the radially outer surface of said rod having at least one longitudinally extending guide groove and having at least one lock groove intersecting each guide groove at substantially a right angle, said rod having a ramp surface in said grooves at each said intersection thereof and a first bearing surface in each said lock groove adjacent each said ramp surface;
• a lock element supported on said other mold part by second mounting means and having a cylindrical opening therein coaxially aligned with and of slightly larger diameter than said tie rod, the surface of said opening having at least one substantially hemispherical projection extending radially inwardly and having thereon a second bearing surface;
• and
• drive means for effecting relative rotation between said tie rod and lock element about the common axis of said rod and said opening;
• whereby as said mold parts move to said closed position, said tie rod is axially slidably received in said lock element opening, each said hemispherical projection is slidably received within a said guide groove and is positioned at a said intersection of said guide and lock grooves when said mold parts reach said closed position, and said relative rotation of said tie rod and lock element by said drive means causes said second bearing surfaces on said projections to contact and be guided by said ramp surfaces onto said first bearing surfaces in said lock grooves, thereby effecting said secure clamping together of said mold parts in said closed position.