| 摘要 |
A signaling interval timer includes a hollow unitary housing having a peripheral slot therein. A sealed flexible hollow elongated bag filled with a viscous liquid is affixed within the housing adjacent to the slot. A spiral coil spring is mounted within the housing and is provided at its outer end with an arm adapted to move along a predetermined path across a surface of the elongated bag. Pressure regulating means are provided for varying the pressure which the arm exerts upon the elongated bag. Signal means are provided for generating an audible signal when the arm moves to a predetermined position along the path.
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