Patent ID: 8079293

Claim:
A perforating machine for forming a plurality of perforation lines in a polymeric vent baffle sheet having first and second opposing ends with at least one spacer extending from a first face of said polymeric vent baffle intermediate said first and second ends, said spacer including a plurality of side stiffeners projecting outwardly from a side surface of the at least one spacer, the perforating machine comprising: a working table including a feed axis, an inlet end and an outlet end; an endless feed belt including teeth projecting outwardly, the endless feed belt having an upper belt portion and a lower belt portion, the lower belt portion positioned a predetermined height above a working face of the working table, the teeth in the lower belt portion being in contact with said side stiffeners for moving the vent baffle sheet generally parallel to the feed axis from the inlet end to the outlet end; a first plurality of perforating wheels and a second plurality of perforating wheels in contact with a surface of the vent baffle sheet to form perforation lines on the vent baffle sheet while the vent baffle sheet moves from the inlet end to the outlet end; a pair of follower towers extending generally perpendicularly from the working table proximate the inlet end, the pair of follower towers rotatably supporting a follower shaft and a follower wheel, the follower shaft and follower wheel spaced from the working table; a pair of drive towers extending generally perpendicularly from the working table proximate the outlet end, the pair of drive towers rotatably supporting a drive shaft and a drive wheel, the drive shaft and drive wheel spaced from the working table, the first plurality of perforating wheels and the second plurality of perforating wheels being positioned between the follower towers and the drive towers so that the teeth of the endless feed belt are engaged with the side stiffeners in said vent baffle sheet when the perforating wheels engage the vent baffle sheet to form the perforation lines; a first backstop wheel and a second backstop wheel mounted to a backstop shaft on an opposite side of the working table from the perforating wheels; a first hole and a second hole in the working table proximate the first and second backstop wheels such that the first plurality of perforating wheels are in engagement with the first backstop wheel through the first hole and the second plurality of perforating wheels are in engagement with the second backstop wheel through the second hole; and wherein the endless feed belt is wrapped around the drive wheel and the follower wheel.