ZERO SPEED INDICATOR TESTING

摘要

The subject invention is directed to methods, processes and decisions on tes t outcomes for testing for faulty, therefor dangerous, performance of zero spe ed indicators (16) that are used to control the opening of barriers guarding moving machine components (17). The indicators (16) may be tested by removin g them from the components (17) during operation without shutting down production or in certain situations the indicators (16) may be tested during the run down phase of the components caused by machine stop initiations. The tests allow to anticipate and hence prevent hazardous opening of barriers du e to a faulty zero speed indication. Additionally, the invention is directed t o testing of the insertion of motion interference devices in conjunction with zero speed indicators, both of which must perform correctly in order to perm it the unlocking and opening of the protective barrier. There are included various exemplary devices for effecting the testing function.