Abstract: The present invention relates to a band feeding and tightening apparatus within a strapping machine wherein an external force tending to cause jamming by means of friction and the like in feeding the band pivotably rotates a chute guide constituting part of a band passage, whereby the rear end portion of the chute guide is pushed upwardly and the band which is loosened by means of a length corresponding to the height of the pushed-up portion of the chute guide is retained within the band passage, so that the external force is momentarily released and the band is smoothly fed to the outside of the main body by means of a continuously rotating feed roller and an upper roller without causing jamming and distortion of the band.The feed roller is driven by means of a series motor and the band is fed at a high rate of speed and a low torque, and then restored so as to perform a primary tightening operation, and finally closely tightened around an article to be strapped at a low rate of speed and a high torque.

Abstract: Indices in the form of colored poles are installed on a ground surface to be digged, and the indices are picked up by a television camera set on one side of a digging machine so as to set a target digging line on rectangular coordinates. Marks are applied to suitable points of the machine and are also picked up by the television camera so as to detect the positions of the marks on the rectangular coordinates. The position of the cutting edge of the machine is calculated by taking the positions of the marks as references. The result of the calculation is stored in a memory device and its content is used to display the locus of the movement of the cutting edge on the screen of a monitor television installed in the cabin of the digging machine while at the same time the target digging line is also displayed on the screen.