摘要 |
<p>HYDRAULIC SYSTEM FOR ELECTRIC LIFT TRUCKS An energy conserving hydraulic system for a lift truck or the like including a hydraulic tilt cylinder and a hydraulic lift cylinder subject to varying load requirements, manually operable valves for controlling the cylinders, a first high volume hydraulic pump, a second, low volume hydraulic pump, a reversible, bidirectional DC motor for simultaneously driving both the pumps, and a piping system connecting the pumps to the valves such that for one direction of drive of the motor, the first pump will deliver a high volume of hydraulic fluid to the valve for operation of the lift cylinder, and for the other direction of drive of the motor, the first pump will be unloaded. A conduit is also arranged such that for the other direction of drive, the second pump will deliver a low volume of hydraulic fluid to the valve for directing the same to the tilt cylinder. An electrical direction control for controlling the direction of drive is responsive to the valves.</p> |