Hydraulic cylinder assembly for dump trailers

A dump trailer comprising:

• a frame;
• a dump box pivotally coupled to the frame;
• a lifting mechanism coupled to each of the frame and the dump box, the lifting mechanism being configured to lift a portion of the dump box relative to the frame;
• and
• a hydraulic cylinder assembly hydraulically coupled to the lifting mechanism and a vehicle hydraulic system, the hydraulic cylinder assembly comprising:
• a first barrel defining a first chamber therein;
• a second barrel rigidly coupled to the first barrel along a longitudinal axis of the hydraulic cylinder assembly, the second barrel defining a second chamber therein, the second chamber being separated from the first chamber by a barrier;
• the first barrel comprising:
• an inlet port remote from the barrier for receiving vehicle hydraulic fluid from the vehicle hydraulic fluid system into a fluid receiving portion of the first chamber;
• and
• an outlet port adjacent the barrier for providing the vehicle hydraulic fluid from a fluid providing portion of the first chamber to the vehicle hydraulic fluid system;
• and
• the second barrel comprising:
• an inlet port adjacent the barrier;
• and
• an outlet port remote from the barrier for providing dump trailer hydraulic fluid to the lifting mechanism of the dump trailer;
• and
• a piston assembly comprising:
• a first piston housed in the first chamber, the first piston dividing the first chamber into the fluid receiving portion and the fluid providing portion;
• and
• a second piston housed in the second chamber, the second piston being coupled to the first piston by a shaft, the second piston dividing the second chamber into the fluid receiving portion and the fluid providing portion, the shaft extending along the longitudinal axis through a bore in the barrier;
• the piston assembly being configured to provide the dump trailer hydraulic fluid to the lifting mechanism to lift a dump box of the dump trailer when the fluid receiving portion of the first chamber receives the vehicle hydraulic fluid from the vehicle.

A method of operating a dump trailer, the method comprising:

• hydraulically coupling a vehicle hydraulic system to a hydraulic cylinder assembly of the dump trailer, the hydraulic cylinder assembly being hydraulically coupled to a lifting mechanism of the dump trailer, the hydraulic cylinder assembly comprising at least one hydraulic cylinder, the at least one hydraulic cylinder comprising:
• a first barrel defining a first chamber therein;
• and
• a second barrel rigidly coupled to the first barrel along a longitudinal axis of the hydraulic cylinder assembly, the second barrel defining a second chamber therein, the second chamber being separated from the first chamber by a barrier;
• injecting vehicle hydraulic fluid from the vehicle hydraulic fluid system into a fluid receiving portion of the first chamber of the first barrel to drive a first piston housed in the first chamber and a second piston housed in the second chamber, the second piston being configured to inject trailer hydraulic fluid housed in the second barrel into the lifting mechanism to lift a dump body of the dump trailer;
• and
• injecting vehicle hydraulic fluid into a fluid providing portion of the first chamber of the first barrel of the hydraulic cylinder assembly to draw trailer hydraulic fluid out of the lifting mechanism and into the second barrel to lower the dump body of the dump trailer.