# US 10,480,814 B1 · Apparatus and process for forming an oval shaped HVAC duct > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,480,814 B1 - Document ID: US10480814B1 - Status: Granted - Kind: B1 - Application number: 15/843,856 - Filed: 2017-12-15 - Granted: 2019-11-19 - Earliest claimed: 2017-03-16 - Applicants: Jose E Rossi - Inventors: Jose E Rossi - Web page: https://patentgrep.com/patent/US10480814B1 ## CPC - B21D 5/14: by passing between rollers (B21D5/06 takes precedence) - F24F 13/0245: {Manufacturing or assembly of air ducts; Methods therefor} - B21B 17/14: without mandrel {, e.g. stretch-reducing mills} - B21B 37/78: Control of tube rolling - B21D 17/04: by rolling - F24F 13/0209: {characterised by their connecting means, e.g. flanges} - B21D 7/08: by passing between rollers or through a curved die - B21D: WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL (working or processing of wire B21F) - F24F: AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING (removing dirt or fumes from areas where they are produced B08B15/00; vertical ducts for carrying away waste gases from buildings E04F17/02; tops for chimneys or ventilating shafts, terminals for flues F23L17/02) - B21B: ROLLING OF METAL (auxiliary operations used in connection with metal-working operations covered in B21, see B21C; bending by rolling B21D; manufacture of particular objects, e.g. screws, wheels, rings, barrels, balls, by rolling B21H; pressure welding by means of a rolling mill B23K20/04) ## Abstract An apparatus and a process for forming an oval shaped duct, as well as a round duct for all required sizes and thicknesses for an AC system, in one continuous operation where two driving rolls advance a flat metal sheet to a multi-positioning bending roll, where the bending roll is moveable to a bending position for different curvatures and a non-bending position. The driving rolls advance the sheet through while the bending roll bends the sheet to form the curved sides, and the bending roll in the non-bending position form the flat sides of the oval shaped duct. A position sensor detects the position of the flat metal sheet in the rolls to control the location along the sheet where the bending roll is moved to either of the bending or non-bending positions while the driving rolls are stopped. ## Claims ### Claim 1 A process of forming an oval shaped HVAC duct in a single pass through a roller machine, the oval shaped HVAC duct having two flat sides and two rounded sides, the process comprising the steps of: forming a first section of a first flat side of the oval shaped duct; forming a first rounded side of the oval shaped duct; forming a second flat side of the oval shaped duct; forming a second rounded side of the oval shaped duct; forming a second section of the first flat side of the oval shaped duct; and, securing the first and the second sections of the first flat side of the oval shaped duct together in a sealed connection; wherein the HVAC duct is a straight duct with a constant cross section flow area from an inlet to an outlet, and the HVAC duct is without any radial flange. ### Claim 2 (depends on 1) The process of forming an oval shaped HVAC duct of claim 1, and further comprising the step of: where the oval shaped duct is a four to six feet in length. ### Claim 3 A process of forming an oval shaped HVAC duct in a single pass through a roller machine, the oval shaped HVAC duct having two flat sides and two rounded sides, the roller machine having two driving rollers and one bending roller located downstream from the two driving rollers, the process comprising the steps of: moving a flat metal sheet to be formed into an oval shaped duct through the two driving rollers with the bending roller in a bending position to form one curved side of the oval shaped duct; moving the bending roller to a non-bending position; moving the flat metal sheet through the two driving rollers to form one flat side of the oval shaped duct; moving the bending roller to a bending position; and, moving the flat metal sheet through the two driving rollers to form a second curved side of the oval shaped duct; wherein the HVAC duct is a straight duct with a constant cross section flow area from an inlet to an outlet, and the HVAC duct is without any radial flange. ### Claim 4 (depends on 3) The process of forming an oval shaped HVAC duct of claim 3, and further comprising the steps of: forming a first section of a second flat side before forming the two curved sides; and, forming a second section of the second flat side after forming the two curved sides. ### Claim 5 (depends on 3) The process of forming an oval shaped HVAC duct of claim 3, and further comprising the step of: prior to moving the bending roller into the bending position or the non-bending position, stopping the two driving rollers from moving the flat metal sheet. ### Claim 6 (depends on 3) The process of forming an oval shaped HVAC duct of claim 3, and further comprising the step of: crimping one end of the oval shaped duct such that a diameter of the crimped end of the duct can fit inside an end of a non-crimped end of a second oval shaped duct. ### Claim 7 (depends on 6) The process of forming an oval shaped HVAC duct of claim 6, and further comprising the step of: adding a ring of sealing material on the crimped end of the machine to prevent leakage of air from two joined ducts when installed in a space. ### Claim 8 (depends on 3) The process of forming an oval shaped HVAC duct of claim 3, and further comprising the step of: forming a plurality of annular shaped beading on the oval shaped duct as the flat metal sheet is being moved through the two driving rollers. ### Claim 9 (depends on 3) The process of forming an oval shaped HVAC duct of claim 3, and further comprising the step of: forming a plurality of annular shaped beading on the oval shaped duct as the flat metal sheet is being moved through the two driving rollers. ### Claim 10 (depends on 3) The process of forming an oval shaped HVAC duct of claim 3, and further comprising the step of: the oval shaped duct with the two curved sides and the two flat sides is formed in one continuous movement through the machine. ### Claim 11 (depends on 3) The process of forming an oval shaped HVAC duct of claim 3, and further comprising the step of: where the oval shaped duct is a four to six feet in length.