He invented a clamping mechanism, when the ropes used to hold up an elevator went slacked, his clamps would grip the elevator's guide rails, keeping it from crashing down.

他发明了一种夹紧机构，当用来支撑电梯的绳索松弛时， 他的夹子会夹住电梯的导轨， 防止电梯坠落。