Abstract: A pressurized-fluid-operated actuator has two piston surfaces for providing increased output force. The actuator includes a hollow piston that is divided into two inner chambers by a stationary inner dividing wall that is rigidly connected with a cylinder end wall. The piston has an outer diameter that is smaller than the inner diameter of the cylinder, and the piston carries three axially spaced sealing rings that define two axially-spaced annular chambers between the piston and the cylinder. Each of the annular chambers is in fluid communication with a respective port provided in the cylinder wall. Introduction of pressurized fluid into one port causes the fluid pressure to act on a single piston surface to retract the piston and rod, and introduction of pressurized fluid into the other port causes the fluid pressure to act on two axially-spaced piston surfaces to provide an increased output force without increasing the diameter of the cylinder and piston and without increasing the pressure of the fluid.

Abstract: A mold core positioning device includes a cam member carried by a first mold segment that is configured to engage a cam follower carried by a second, cooperating mold segment. The cam follower is provided on a core slide to which an outwardly extending core member, such as a core pin, is connected. The core slide is movable toward and away from a mold cavity to move the core pin into and out of a position within the mold cavity. The cam member includes an extension cam surface and a withdrawal cam surface. The withdrawal cam surface includes a breakaway cam surface that causes slow retraction of the core pin relative to the molded part, and a retraction cam surface that causes more rapid withdrawal of the core slide and core pin after the core pin has been initially separated from the molded part.

Abstract: An injection molding machine is provided with an open frame specifically designed to avoid angular displacement of the stationary platen during the molding process. More particularly, the stationary platen and the supporting frame are configured to maintain a constant moment of inertia relative to the line of force acting on the platen during the clamp closed part of the cycle, so that it displaces linearly when force is applied. In addition, the frame is provided with integral support members to connect with the die height adjustment mechanism. The support members are positioned on the frame to minimize the distance of the open frame, thus minimizing the length of frame subject to deflection when the force is applied.