| 摘要 |
<p>of the disclosure A working-time indicator that resets itself to a zero position as soon as the supervised work is interrupted for a predetermined, preferably adjustable minimum period of time but neglects all pauses of a shorter duration comprises, in combination, a first or working-time meter that is adapted to measure and indicate the duration of a single period or a succession of spaced periods between an arbitrary number of start and stop pulses received thereby, said first meter being resettable to a zero position by means of a resetting pulse, and a second or idling-time meter that is adapted to measure the period of time following immediately after each stop pulse to said first meter and to compare the length of each such period of idling with a preferably adjustable reference value, means being provided for automatically resetting said second meter to a zero position, if and when said first meter receives a new start pulse before the length of the period of idling has reached the reference value, and means being also provided for supplying a resetting pulse to said first meter at the vary moment when the length of the period of idling measured by said second meter equals said reference value.</p> |
