| 摘要 |
<p>PURPOSE:To detect the removal of one of a pair of brushes before the other comes off by constructing a trolley by alternately disposing nonconductive units shorter than the interval of the brushes arranged at the front and rear parts of a truck and conductive units set longer than the nonconductive units. CONSTITUTION:A pair of brushes 6a, 6b arranged at an interval L1 at the front and rear parts of a truck 2. A trolley 3 attached to a rail 1 is composed by alternately disposing nonconductive units 3a each having a length L2 set at the length shorter than the interval L2 and longer than a distance that the truck 2 stops in the state from the power supplying state to the power interrupting state, and conductive units 3b each having a length L3 (>L2). When the brush 6b approaches the nonconductive unit 3a in the state that the pair of brushes 6a are removed, the truck 2 stops. Thus, a magnetic sensor 10b examines a striker 10a for a predetermined time and outputs an abnormal signal.</p> |
