Apparatus and method for a helically perforated wound duct

Abstract

The first roller dies will perforate, puncture the metal strip after the strip goes through the front guide. After the perforation the metal strip can then be corrugated. This is an improvement over punching the metal strip. Punching the metal, rotary punch, requires and extra step and leaves metal scrap, which is why punching metal for the first rolls would clog the machine and cause damage to the machine. The results of these tiny holes in the cylindrical duct help muffle the vibration and other noises from the motorized fan down the ductwork. The cylindrical perforated duct acts like a muffler. Air conditioning, bathroom exhaust fans, kitchen exhaust fans noise can me great reduced cheaply and efficiently. This perforated duct will be used with a vapor barrier and/or insulation.

What is claimed is: 
     
         1 . An apparatus for producing a helically wound duct from a strip, the apparatus comprising:
 An elongated strip frame coupled to an elongated duct frame;   A front guide coupled to said elongated strip frame for adjusting the tracking of the strip;   A first position roller die to puncture, perforate the metal strip;   A plurality of pair of corrugated roller dies coupled to said elongated strip frame for progressively corrugated the perforated strip;   A finishing pair of corrugated roller dies couple to said elongated strip frame for creating a primary ascending leg in the primary edge of the strip and a secondary leg in the secondary edge of the strip;   A strip guide couple to said elongated strip frame for adjusting the tracking of the strip;   A plurality of helically disposed roller dies coupled to said elongated strip frame for creating a helically wound duct;   A jointer guide couple to said elongated strip frame having a guide body extending between a exterior surface, an interior surface, a first side surface, a second side surface, a bottom surface and a top surface;   guide shoulder extending from said interior surface of said guide body;   A guide arm coupling to said guide shoulder for defining a guide channel between said interior surface of said guide body and said guide arm;   Said exterior surface of said guide arm defining a primary leg guide surface   Said primary leg guide surface maintains contact with the primary ascending leg the strip for defining primary alignment tool;   Said external surface of said guide arm having a recessed secondary leg guide surface;   Said recessed secondary leg guide surface maintains contact with the secondary descending leg of the strip for defining a secondary alignment tool;   A front tucker having a radius finger for progressively bending the primary edge and the secondary edge of the strip;   A rear tucker having a tapered edge for converging the primary edge and the secondary edge of the strip into said radius finger;   Said primary alignment tool and said secondary alignment tool assist in aligning the primary ascending leg and the secondary descending leg of the strip before entering said front tucker and said rear tucker;   A pair of knurl corrugated roller dies compressing and knurling said primary edge with the secondary edge of the strip for defining a continuous helically seam;   Said helically wound strip and said continuously helically seam defining a cylindrical duct;   A saw device coupled to said elongated duct frame for cutting said cylindrical duct to length   
     
     
         2 . An apparatus for producing helically wound duct from a strip as set for in  claim 1 , wherein said top surface of said guide arm further includes a taper arm surface for directing secondary descending leg into said recessed secondary leg guide surface; and said top surface of said guide body includes a taper body surface for directing the secondary descending leg into said recessed secondary leg guide surface. 
     
     
         3 . An apparatus fix producing a helically wound duct from a strip as set forth in  claim 1  further including an expansion corrugated roller compressing against one of said plurality of helically disposed roller dies for maintaining a consistent diameter for said cylindrical duct. 
     
     
         4 . A method for producing a helically wound duct from a metal strip. The methods
 Comprising the steps of adjusting the tracking of the strip with a front guide; the first roller dies perforate, puncture small holes in the strip before corrugation. Corrugating the perforated strip with a plurality of pair of corrugated roller dies; forming a primary ascending leg in the primary edge of the strip and a secondary descending leg in the secondary edge of the strip with a finishing pair of corrugated roller dies;   Adjusting the tracking of the strip with a strip guide;   Forming a helically wound strip with a plurality of helically disposed roller dies;   Maintaining the primary ascending leg of the strip against a primary leg guide surface;   Maintaining the secondary descending leg of the strip against a recessed secondary leg guide surface;   Bending and interlocking the primary edge with the secondary edge of the strip with the front tucker and a rear tucker;   Compressing and knurling the primary edge with the secondary edge of the strip with a pair of knurl corrugated roller dies; and cutting the helically wound duct with a saw.   
     
     
         5 . A method for producing a helically wound duct, the methods comprising the steps of positioning a metal strip through a flattening roll;
 Adjusting the tracking of the strip with a read guide;   Dipping the metal (copper, zinc both antimicrobial, or aluminum, steel) strip into the lubricating dip tank;   Inserting the metal strip into a squeegee roller for removing excess fluid;   Adjusting the tracking of the strip with a front guide;   Using the first pair of roller dies that puncture, perforate the metal strip then corrugating the strip with polarity of pair of the corrugated roller dies;   Forming a primary ascending leg in the primary edge of the strip and a secondary descending leg in the secondary edge of the strip with a finishing pair of corrugated roller dies;   Adjusting the tracking of the strip with a strip guide;   Forming a helically wound strip with a plurality of helically disposed roller dies;   Compressing an expansion corrugated roller die against one of said plurality of helically disposed roller dies for maintaining a consistent diameter for said cylindrical duct;   Maintaining the primary ascending leg of the strip against a primary leg guide surface;   Maintaining the secondary descending leg of the strip against a recessed secondary leg guide surface;