Patent ID: 6910586

Claim:
A portable trommel comprising: a) a chassis, including support wheels at one end thereof for movement of the portable trommel; b) a trommel rotatably mounted on the chassis and having an input end, an output end, and a trommel screen; c) input means for supplying material to be screened to the input end of the trommel, the input means being mounted on the chassis adjacent the input end of the trommel; d) output means for collecting material passing through the trommel screen, the output means being mounted on the chassis, below the trommel; e) a stockpiling conveyor mounted on the chassis and having a lower end for receiving screened material from the output means and having an upper end for discharging screened material to form a stockpile, wherein the stockpiling conveyor comprises a lower part pivotally attached to the chassis and an upper part pivotally attached to the lower part, the lower and upper parts being movable between an extended position in which the stockpiling conveyor extends upwardly and outwardly from the chassis, and a retracted position for transportation in which the lower part is at an angle to the upper part, f) one or more mechanical linkages connecting the lower and upper parts of the stockpiling conveyor; g) a first locking means to prevent relative movement between said lower and upper parts; h) a second locking means for locking the lower part of the stockpiling conveyor in a selected position; and i) a hydraulic ram assembly mounted between the chassis and said one or more mechanical linkages, wherein at least one of said one or more mechanical linkages is lockable using said first locking means such that activation of the hydraulic ram assembly displaces the lower and upper parts together, and wherein said at least one mechanical linkage is unlockable to permit relative movement between said lower and upper parts such that, with said lower part locked in said selected position by said second locking means, activation of the hydraulic ram assembly displaces the upper part of the stockpiling conveyor relative to the lower part.