Abstract: The positions of selected valves are determined by measurement of their respective retainers by means of displacement gauges. When a given piston is at top dead center in the compression stroke, the retainers of the intake and exhaust valves of that piston are not displaced, but when that same piston is at the top dead center position in the exhaust stroke the intake and exhaust valve retainers of that cylinder are displaced to known positions as are intake and exhaust valve retainers of certain other cylinders, thereby indicating whether the crank position is such as to place the selected piston in the top dead center position of the compression stroke or in the top dead center position of the exhaust stroke. Inability to obtain correct correlated readings for the retainers of the related valves indicates likelihood of misassembly of the cotters on one or more of the valves.

Abstract: Valve lifts are measured with a reference engine assembled correctly, at at least two crank angles, and the relationship between the crank angle and the valve lifts is memorized in an arithmetic unit. Thereafter, the crank shaft of an engine, the valve actuating system of which is to be examined, is indexed at the above-mentioned crank angles in the assembled state of the engine, and the valve lifts are measured at these crank angles. The measured data are delivered to the arithmetic unit which performs an arithmetic operation to determine whether there is any abnormality in the valve actuating system and to make the display of the result of the determination.

Abstract: The presence and location of a crank pulley bolt on one end of an internal combustion engine is detected by moving a sensing surface on a jig toward the bolt location until it stops, either by contact with the bolt or the pulley, if the bolt is missing. Then a sensor rigidly connected to the sensing jig detects the position of the jig relative to the V-shaped rim of the pulley.

Abstract: There is disclosed a system for predicting desynchronization of a synchronous machine by detecting a phenomenon of radical variation of the magnetic flux in the gap of a synchronous machine immediately before falling in an asynchronous state. For example, a functional value of the fundamental harmonic component and that of the higher harmonic component of the flux in the gap are detected for comparing the variation of each functional value with a predetermined reference level to predict desynchronization of the synchronous machine.

Abstract: Desynchronization of a synchronous machine is predicted by detecting a phenomenon of radical variation of the magnetic flux in the gap of a synchronous machine immediately before falling into an asynchronous state. For example, each functional value of the direct axis flux and the quadrature axis flux in the gap is detected for comparing the variation of each functional value with a predetermined reference level to predict desynchronization of the synchronous machine.

Abstract: A waterproof sheet for a cargo chamber of an aircraft comprising a base sheet adapted to lie on the floor of the cargo chamber and having notched portions at positions corresponding to the doors of the cargo chamber; door sill flaps provided to the base sheet around the notched portions and adapted to be folded up and down at the time of opening and closing of the cargo chamber door; door sill protectors provided to the base sheet at the notched portions for protecting the door sill flaps; side sheets provided at the longitudinal sides of the base sheet and having tape fasteners for securing the side sheets to the wall of the cargo chamber, and end sheets provided at both longitudinal ends of the base sheet and the side sheets, the end sheets having tape fasteners for tucking them when the base and side sheets are properly positioned in the cargo chamber.