Synchronous single- and double-acting piston feeder system and method

A feeder apparatus for advancing a compressible material, comprising:

• a double-acting first piston cylinder assembly (1004) including a first hydraulic cylinder (24) having first and second first piston rams (40a, 40b) arranged to travel in opposite directions within respective first and second first cylinders (10a, 10b), each first cylinder (10a, 10b) having a feedstock inlet (42, 42b);
• first and second single-acting second piston cylinder assemblies (1006a, 1006b), each including a second hydraulic cylinder (48a, 48b) having a corresponding second piston ram (64a, 64b) arranged to travel in respective first and second second cylinders (12a, 12b), each second cylinder (12a, 12b) having a second pipe branch opening (72a, 72b) coupled to a respective one of the first and second first cylinders (10a, 10b), such that feedstock transferred through a first cylinder (10a & 10b) by the advancing motion of a corresponding first piston ram (40a & 40b) is then transferred into a corresponding second cylinder (12a & 12b);
• and
• a double-acting third piston cylinder assembly (1008) including a third hydraulic cylinder (74) having first and second third piston rams (90a. 90b) arranged to travel in opposite directions within respective first and second third cylinders (14a, 14b), each third cylinder (14a, 14b) having a third pipe branch opening (98a, 98b) coupled to a respective one of the first and second second cylinders (12a, 12b).