Patent ID: 6216797
Filing Date: 2001-04-17
Classification: B23Q,E21B

Abstract:
A thrust system for a horizontal directional drill, comprising:a drill boom extending along a longitudinal axis and terminating at first and second opposite ends, the drill boom including a drive sprocket positioned at the first end of the drill boom and a driven sprocket positioned at the second end of the drill boom;a drill carriage supported by the drill boom for movement therealong, the carriage having first and second idler sprockets positioned between the drive sprocket and the driven sprocket in the drill boom; anda single chain having a first end independent of the carriage and fixed within the drill boom adjacent the first end of the drill boom for preventing movement thereof and a second end independent of the carriage and fixed within the drill boom adjacent the second end of the drill boom for preventing movement thereof, the chain extending sequentially from said first end of said single chain about the first idler sprocket, the drive sprocket, the driven sprocket and the second idler sprocket to said second end of said single chain such that rotation of the drive sprocket in a first direction draws the carriage towards the first end of the drill boom, androtation of the drive sprocket in a second direction draws the carriage towards the second end of the drill boom.