LOCKING DEVICE FOR AN INJECTION MOLDING MACHINE

A locking device, releasably securing a tie bar to a platen, includes a housing with a bearing surface affixed to the platen coaxial with the tie bar, and a rotatable lock nut received in the housing and comprising: an inner bore with radial elements engaging the tie bar to transfer an axial clamp load to the lock nut, the elements defining an engagement portion along a lock nut first axial extent; an outer surface with at least a first step face abutting the bearing surface to transfer the axial damp load to the platen, the step face having a first radially outer extent; and a narrowing section having a second axial extent from a first position having a first diameter proximate the step face to a second position having a second lesser diameter spaced axially towards a second platen, the first diameter being less than the first radially outer extent.