Patent ID: 6823616
Filing Date: 2004-11-30
Classification: E02F

Abstract:
A method of excavating a surface layer of soil by using an excavator comprising a grab having two bucket halves, each grab having a cutting edge, comprising the steps of:a) controlling the grab to hold the grab in a first orientation in a first excavating position as seen in projection on a horizontal plane and inserted into the layer of soil in an open position of the bucket halves until their cutting edges reach a first predetermined level while maintaining said first orientation; b) while maintaining that level and first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a first rectangular portion of the layer of soil; c) the grab is lifted and moved to a discharge position horizontally spaced from the excavating position and emptied there to make further transport of the excavated soil possible; d) the grab is moved towards a second excavating position and held in said first orientation and inserted into the layer of soil in an open position of the bucket halves until their cutting edges reach a second predetermined level; e) while maintaining that level and said first orientation, the bucket halves are moved to a closed position during which movement their cutting edges move towards each other through a substantially straight path so as to excavate a second rectangular portion of the layer of soil, said second portion being adjacent to said first portion before excavation; f) the grab is lifted and moved to a discharge position horizontally spaced from the first and second excavating positions and emptied there to make further transport of the excavated soil possible; and g) whereafter steps d, e and f are repeated in a corresponding manner for excavating subsequent third, fourth, etcetera rectangular portions until the layer of soil is excavated.