摘要 |
PURPOSE:To enable the observation of timing either in a light atmosphere or in an adverse environment, by constituting a shutter plate having a slit formed thereto and a scope arranged in coaxial relation to one place of the passing position of said slit. CONSTITUTION:Whenever a pulse is issued from a signal generator 3 transmitting a pulse signal generated every one rotation of an approach switch drive member 2, a divider 5 generates a pulse. An observer can view an observing part in a moment when the axial line of lenses 15, 16 is coincided with a slit 14 but it is impossible to view the same at the other time. Therefor, if the pulse signal obtained by rotating a main shaft 1 is delayed by time delay apparatuses 6, 6' to be coincided with the phase of a part 17 to be observed, the observer can observe the operational state or the phase angle of a drive machine element as if in the state of stationary. |