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| Illustration 1 | g03714556 |
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Typical view of a hoist cylinder (1) Second stage rod assembly (2) First stage rod assembly (3) Body assembly | |
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| Illustration 2 | g03714564 |
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View of area (A) ( 4) Extend port (5) Retract port | |
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| Illustration 3 | g03734865 |
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Cross section of a typical hoist cylinder (1) Body assembly (2) Drain orifice in first stage rod assembly (3) Cylinder piston (4) Three orifices in second stage rod assembly (5) Chamber between first stage rod assembly and the body assembly (6) First stage rod assembly (7) Chamber between first stage rod assembly and second stage rod assembly (8) Second stage rod assembly (9) Cylinder head assembly (10) Extend port (11) Retract port (12) Chamber in the head end of the body assembly (13) Retainer ring (14) Snap ring | |
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| Illustration 4 | g03735066 |
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Hoist cylinder retracted | |
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| Illustration 5 | g03735098 |
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Hoist cylinder with stage one extended | |
Two hydraulic cylinders are used to raise the truck body. When the hoist control is held in the RAISE position, the pump oil extends the two-stage cylinders to the dump position.
The hoist cylinders raise the truck body in two stages. The pump oil flows into the cylinder assembly through port (10). The oil flows through a tube in second stage rod assembly (8) into chamber (12) in the head end of body assembly (1). The pressure of the pump oil in chamber (12) moves body assembly (1). The cylinder moves upward until cylinder head assembly (9) contacts the lip on the end of first stage rod assembly (6).
As body assembly (1) moves, hydraulic oil that is in chamber (5) flows through orifices (2) and orifices (4). The hydraulic oil flows into the center of second stage rod assembly (8). The hydraulic oil flows through internal passages to port (11). The hydraulic oil flows through the port to the hoist valve, and to the tank.
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| Illustration 6 | g03735318 |
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Hoist cylinder with stage one and stage two extended | |
When cylinder head assembly (9) reaches a lip on the end of first stage rod assembly (6), first stage rod assembly (6) is pushed down by the oil in chamber (12). The cylinder extends until cylinder piston (3) contacts the end of first stage rod assembly (6).
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| Illustration 7 | g03735387 |
Move the hoist control to the LOWER position or to the FLOAT position in order to lower the truck body to the truck frame. In the LOWER position, the pressure from the hydraulic oil and the weight of the truck body lowers body assembly (1) and second stage rod (8) followed by the first stage rod (6) retraction.
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| Illustration 8 | g03735425 |
Move the hoist control to the LOWER position. The truck body is lowered when the pump oil flows through port (11) into the internal space in second stage rod assembly (8). The hydraulic oil fills the space and flows through orifices (1). The second stage rod (8) will retract first, followed by the first stage rod (6) retraction.
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| Illustration 9 | g03735450 |