Patent ID: 6895699

Claim:
A method of setting a maximum angle of rotation of a boom of an excavating machine, the rotation of the boom produced by a hydraulic cylinder having a piston with a lockable slider block on the piston, the excavating machine having a sensor coupled to a hydraulic valve for controlling hydraulic pressure to the hydraulic cylinder, comprising the steps of: (a) pre-rotating the boom to the maximum angle of rotation; (b) locking the lockable slider block on the piston when the boom is at the maximum angle of rotation in a direction; (c) rotating the boom to an angle less than the maximum angle of rotation; and (d) causing the lockable slider block to engage the sensor on each occasion that the boom rotates in the direction to the maximum angle of rotation again after step (a), whereby engagement of the sensor causes actuation of the hydraulic valve which prevents further rotation of the boom by the hydraulic cylinder.