| 摘要 |
<p>A treadle switch assembly (10) includes at least one elongated treadle (12, 14) of a compressible, resilient material containing a hollow passageway (24) throughout its length. It also includes a photocell emitter (34) and collector (36) inserted into opposite ends of the passageway (24). When the treadle (12, 14) is compressed by a vehicle, the passageway (24) is mashed and closed to interrupt the radiation beam from the emitter (34) to the collector (36), whereby the collector (36) generates a signal indicative of the passage of the vehicle, which signal may be used to operate counter (70) or signal device. The passageway (24) may be formed with an oval or elliptical cross section to enhance closure of the passageway (24) to interrupt the radiation beam. In the alternative, the emitter (54) and collector (56) may be in a single unit (50) type disposed in one end of the treadle (12, 14) while a reflector (52) is disposed at the other end.</p> |
