US 5,979,729 A · Separating a web at a line of weakness

Abstract

This invention pertains to apparatus and methods for breaking a web along spaced lines of weakness. The invention includes a compact breaker bar assembly comprising at least one breaker bar in a gap. The apparatus also includes driving apparatus to power the breaker bar assembly in breaking the web. In some embodiments, one or more breaker bars engage and stress the web along a single transverse line across the web, breaking the web. In other embodiments, at least first and second breaker bars engage and stress the web along spaced first and second transverse lines across the web. The breaker bars can be mounted on one or more rotary elements, or can be mounted on one or more belts or other breaker bar carriers, traversing closed-loop paths. In preferred embodiments, the breaker bar assembly comprises at least two breaker bars, a first breaker bar following a first straight-line path segment while a second breaker bar follows a second opposing straight line path segment, both breaker bars engaging and stressing the web at the same time, both breaker bars following the straight-line path segments before engaging the web, during engaging and stressing of the web, while breaking the web, and after breaking the web.

Claims35

Dependent claims

Apparatus for breaking a web having a length and a width, the web having a line of weakness therein and traveling in a direction, said apparatus comprising:

(a) first and second driven rolls forming a first nip, and receiving and transporting the web through the first nip;
(b) breaking apparatus downstream of the first nip, said breaking apparatus receiving the web and comprising (i) a first rotary element which rotates about an axis of rotation, which extends along the length of the web, the first rotary element having at least a first breaker bar, and (ii) driving apparatus driving said first rotary element and said at least first breaker bar in a downward direction, said first breaker bar engaging a top surface of the web;
and
(c) a second nip downstream of said breaking apparatus, receiving and transporting the web through the second nip
so that movement of said first breaker bar in the downward direction engages the web, causing the web to break.

2 more elements

Apparatus for breaking a web having a length and a width, and having a line of weakness therein, said apparatus comprising:

(a) first and second driven rolls forming a first nip, and receiving and transporting the web through the first nip;
(b) breaking apparatus downstream of the first nip, said breaking apparatus receiving the web, and comprising at least one breaker bar traveling in a path perpendicular to the direction of travel of the web at engagement of said at least one breaker bar with the web;
(c) driving apparatus driving said breaking apparatus into engagement with the web at a locus of engagement defined by a single line of contact between said breaking apparatus and the web, across the width of the web, causing the web to break at the line of weakness and;
(d) a second nip, downstream of said breaking apparatus, receiving and transporting the wet through the second nip.

1 more element

Dependencies are inferred from the claim text.

Separating a web at a line of weakness

Life of this patent

Separating a web at a line of weakness

Life of this patent

Abstract

Claims35