| 摘要 |
<p>The unwinding mechanism has a drive operating in either direction and with first and second driving pulleys coupled respectively by elastic belts to first and second riven ones. The latter are coupled to first and second rotary components working with first and second rotary supports and parallel to each other. The opposite ends of a strip of material are secured to the supports, so as to wind off one and onto the other and back again. Between the first support and the first rotary component at least is a unidirectional mechanism with moving components applying friction to the support. A mechanism is included to allow a limited amount of angular movement between the first driving pulley and the second rotary component, typically a protrusion working in an oblong recess in the second driving pulley.</p> |
