Patent ID: 8641399

Claim:
An injection molding system ( 20 , 220 , 320 , 420 ) having a hydraulic circuit ( 50 , 250 , 350 , 450 ) for motivating at least one hydraulic actuator ( 36 , 38 ), the injection molding system ( 20 , 220 , 320 , 420 ) comprising: a pump motor ( 52 ); and at least one digital displacement pump ( 54 , 354 A, 354 B, 454 A, 454 B), the at least one digital displacement pump ( 54 , 354 A, 354 B, 454 A, 454 B) having: a plurality of piston assemblies ( 102 A, 102 B, 102 C, 102 D) being actuatable by the pump motor ( 52 ), each piston assembly of the plurality of piston assemblies ( 102 A, 102 B, 102 C, 102 D) including: a pair of inlet and outlets ( 108 A and 112 A, 108 B and 112 B, 108 C and 112 C, 108 D and 112 D) that are operable to be individually opened and closed at a selective rate independently of actuation of the each piston assembly of the plurality of piston assemblies ( 102 A, 102 B, 102 C, 102 D); the at least one hydraulic actuator ( 36 , 38 ) being operably coupled on each of a rod side ( 64 , 66 ) and a cylinder side ( 58 , 74 ) to a first subset of the plurality of piston assemblies ( 102 B, 102 D) and a second subset of the plurality of piston assemblies ( 102 A, 102 C), respectively.