Opinion ID: 405101
Heading Depth: 2
Heading Rank: 2

Heading: Background of Invention

Text: 20 5. The invention relates to a web-winding apparatus and method and, more particularly, to that machine which paper converters refer to as an automatic rewinder. Apparatus of this character is employed when a wound web must be unwound and then rewound into smaller rolls. Illustrative of this operation insofar as paper is concerned is toilet tissue and paper toweling. 21 6. The apparatus serves to unwind the large diameter paper rolls provided by the paper machine and thereafter rewind the web onto cores for individual use. The parent roll may be several feet in diameter, and it is desired to unwind this roll continuously and at a relatively high rate of speed-of the order of 2,000 feet per minute. So the final retail size rolls of toilet paper and toweling take only a few seconds to wind. 22 7. Before the advent of the automatic rewinders, it was necessary to employ stop-start rewinders where the unwinding and rewinding operation was intermittent. The stopping was necessary in order for a new mandrel-the shaft for carrying the cardboard core-to be placed in the path of the web being unwound. The automatic rewinder solved this problem by automatically moving the new mandrel into the path of the web being unwound while the web was still being wound on another mandrel. 23 8. In prior art automatic rewinders, the cutoff occurs at a position between adjacent mandrels. The rewinder is equipped with six mandrels, each of which goes through the same orbital path. This achieves the following sequence: (1) the mandrel is equipped with a cardboard core on which the toilet paper or toweling is wound, (2) the core faced with glue, (3) the actual winding, and (4) the removal of the wound roll from the mandrel. 24 9. Near the end of rewinding on a given mandrel core, the subsequent mandrel is in a position close to the fast traveling web so as to pick it up and continue the rewinding operation when the web has been severed. 25 10. To achieve transfer of the web from the one mandrel to another, it was necessary to synchronize the cutting of the web with engagement of the web with the new mandrel-that mandrel just about to commence the web-winding operation. This became increasingly difficult to do as machine speeds exceeded 1,000 feet per minute. A certain amount of time was required for the knife to emerge, cut the web, have the associated pushers push the leading edge portion against the glue on the new cardboard core, and retract. This had to happen at a precise orientation of the bedroll so that it only could be done at relatively slow speeds. Trying to speed up the emergence retraction time of the knife resulted in a different problem. Since there was a certain amount of mass involved in the knife-pusher mechanism, moving it faster resulted in wear and premature failure.