A drilling machine includes a frame, a tower that is supported by the frame, two tracks for movement over the ground, at least three yokes that interconnect the frame and the two tracks, at least three hydraulic cylinders, an inclinometer that senses the inclination of the frame and produces an output signal that is indicative of the inclination of the frame, and a controller that receives the output signal from the inclinometer. The tower includes a drill string. Each yoke is connected to the frame and one of the tracks. Each hydraulic cylinder is extendible and retractable in response to an associated control signal and connected to the frame and an associated yoke. The controller generates control signals for the hydraulic cylinders such that the hydraulic cylinders are controlled to extend or retract to maintain the frame in a level position.

 
Web www.patentalert.com

< Power unit supporting structure of scooter type vehicle

> Activation control apparatus for occupant protection apparatus

~ 00482