Hydraulic clamping apparatus for an injection molding machine

Abstract

A hydraulic clamping apparatus for use with injection molding machines and including a first hydraulic actuator having a first cylinder and a first hollow, cup-shaped piston with a closed head portion disposed for reciprocating movement within the first cylinder, and a foot portion axially spaced from said head portion and defining an opening; a second hydraulic actuator having a second piston, a rod extending axially through the opening into the first piston and connected between the first and second pistons, and a second cylinder mounted for reciprocating movement on the second piston and through the opening between a recessed position substantially within the first piston and an extended position substantially outside the first piston; and a clutch operable in the extended position of the second cylinder to produce engagement thereof with the first piston. The overall length of the apparatus is minimized by placement of the second actuator cylinder within the first piston.

Dependencies are inferred from the claim text.