COMMERCIAL TREE CHIPPER: THE LEG PULL-IN HYPOTHESIS

摘要

Thispaper addresses a commercial mobile tree chipper with amechanical infeed system that is manually fed. The purpose of this paper is to show that tree branches and brush presented to adisc chipper through the infeedhopper will not pull an erectly standing operator's leg off the ground and into the feed wheels given the conditions set forth in this test program. In order for an erectly standing operator's leg to contact the feed wheels, it is necessary for the leg to be pulled off the ground and over the bottom leading edge of the infeed hopper. Experiments demonstrate that the operator's leg is pulled up against the lower leading edge of the infeed hopper and lodges there during pull-in scenarios using a winch, cable, and rope attached to the operator's ankle. Two safety devices, an infeed extension pan and a safety control bar are explored in this paper.