Non-obstructive centering linkage mechanism for stack mould

An injection moulding machine, comprising:

• a support structure;
• a stationary platen with a mould plate, fixed to the support structure;
• a moveable platen with a mould plate;
• a primary drive for axially reciprocating the moving platen between an open position and a closed position;
• at least one moveable center section having first and second mould plates on opposing sides thereof, the first mould plate facing the stationary platen mould plate so as to define a first set of mould cavity spaces when the moveable platen is in the closed position, the second mould plate facing the moving platen mould plate so as to define a second set of mould cavity spaces when the moveable platen is in the closed position;
• a centering linkage mechanism for converting the reciprocating movement of the moveable platen to corresponding reciprocating movement of the center section;
• characterized in that the centering linkage mechanism includes:
• a lever pivotally mounted to a fixed structure, such as a stationary back plate, so as to defining a base joint;
• a first linkage bar having first and second ends, the first end pivotally connected to the moving platen, and the second end pivotally connected to the lever so as to define a first joint;
• a second linkage bar having first and second ends, the first end pivotally connected to the center section, and the second end pivotally connected to the lever so as to define a second joint.