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.

Abstract: Improved method and apparatus for injecting fuel for a diesel engine are disclosed which are constructed such that a push rod is disposed in a nozzle body and fuel is injected into a combustion chamber by actuating the push rod. The improvement of the invention consists in that push rod actuating force is accumulated for a certain period of time while the push rod is stationarily held by means of an electromagnetic coil which is energized. Fuel injection is thus carried out by releasing the accumulated force by way of deenergization of the electro-magnetic coil. In an embodiment of the invention push rod actuating force is extracted from a cam driving mechanism and a coil spring disposed between the cam driving mechanism and the push rod serves as a push rod actuating force accumulating means.

Abstract: In a preheating apparatus of a diesel engine of the type wherein, at the time of starting the engine, a fuel pump is used to inject fuel through a nozzle into a precombustion chamber provided with a preheating device, and the suction air preheated by the combustion of the fuel injected into the precombustion chamber is supplied into the combustion chamber of the engine, until the speed reaches a certain predetermined value and with a substantially constant, small amount of fuel when the speed of the engine is in excess of the predetermined value, the opening of the nozzle is controlled in accordance with the speed of the engine.