| 摘要 |
Apparatus and methods are disclosed for breaking a web (20) along spaced lines of weakness, wherein a compact breaker bar assembly (16) comprising at least one breaker bar (52); the apparatus includes driving apparatus (56) to power the breaker bar assembly (16) in breaking the web. The one or more breaker bars (52) engage and stress the web along a single transverse line across the web (20), breaking the web. In preferred embodiments, first and second breaker bars (52) engage and stress the web (20) along spaced first and second transverse lines across the web, the breaker bars (52) being mounted e.g. on one or more rotary elements (54A,B) or on one or more belts (99,100) or other breaker bar carriers, traversing closed-loop paths. The preferred breaker bar assembly (16) comprises at least two breaker bars (52A,B), a first breaker bar (52A) following a first straight-line path segment while a second breaker bar follows a second opposing straight line path segment (107), both breaker bars (52A,B) engaging and stressing the web (20) at the same time, and both breaker bars (52A,B) following the straight-line path segments (106,107) before engaging the web, during engaging and stressing of the web, while breaking the web, and after breaking the web. |
