Apparatus for separating a movable mold section from a fixed mold section includes a linkage of an elongate arm pivotally mounted at about its midpoint and having a first end pivotally secured to the movable mold section and a second end in engagement with a cam for pivoting the arm. An elongate link also has one end pivotally secured to a support and its opposed end pivotally secured to the movable mold section. The pivotal mounting points of the link are disposed between the mounting points of the arm and above them whereby upon pivoting of the arm, the movable mold section is first moved away from the fixed mold section in a straight line and then in an arcuate path.