摘要 |
The telescoping system includes a first and second fluid motor (2, 1). The first fluid motor (2) includes a first cylinder (16) and a second cylinder (8, 10) nested in the first cylinder (16). The second fluid motor (1) includes the second cylinder (8, 10) and a piston (4, 6) disposed in the second cylinder (8, 10). The second cylinder (8, 10) has a double barrel outer wall (52) forming a hydraulic fluid passageway. A hydraulic control system (48, 50, 44, 46, 60, 63, 64) in the telescoping system includes a single control valve (60), solenoid valves (44, 46), and holding valves (48, 50), and controls extension and retraction of the telescoping system. <IMAGE> |