Patent ID: 6474933
Filing Date: 2002-11-05
Classification: E02F

Abstract:
A method of moving a material handling tool in a lift path using a skid steer prime mover having a longitudinally extending frame with supports fixedly attached to the frame and extending upwardly from the frame;a boom assembly including a main boom section having arm members on each side of the prime mover with a linkage for supporting a rear end of the main boom section relative to the supports on the frame, the linkage including a fixed length link on each side of the prime mover pivoted to upper ends of the supports and to the main boom section on fixed position axes and inclining upwardly and forwardly from the supports to the pivot of the fixed length link to the main boom section with the main boom section lowered, and a material handling tool that is to be raised and lowered attached to a forward end of the main boom section; a hydraulic actuator for pivoting the main boom section to raise and lower the forward end of the main boom section and the material handling tool for moving said tool along the lift path, including the steps of: pivotally connecting a control link to the main boom section, and to the frame on fixed position axes and guiding and moving said tool from a known position, as said tool is initially moved upwardly along its lift path in a substantially vertical direction to an intermediate position in its lift path while causing movement of the fixed length links rearwardly about their Divots to the supports to a rearward pivoted position; and subsequently moving said tool upwardly from said intermediate position along a path that continually moves forwardly by controlling the fixed length links to move forwardly by positioning the pivots and selecting the length of the control link to complete the lift path at a final position where the tool is forward of said intermediate positions thereby forming an S-shaped lift path between the known position and the final position.