# US 6,772,617 B1 · Method and apparatus for in-situ leveling of progressively formed sheet metal > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,772,617 B1 - Document ID: US6772617B1 - Status: Granted - Kind: B1 - Application number: 10/350,863 - Filed: 2003-01-24 - Published: 2004-07-29 - Granted: 2004-08-10 - Earliest claimed: 2003-01-24 - Assignees: GenCell Corporation - Inventors: Jeffrey Peter Allen - Web page: https://patentgrep.com/patent/US6772617B1 ## CPC - B21D 1/00: Straightening, restoring form or removing local distortions of sheet metal or specific articles made therefrom (B21D3/00 takes precedence); Stretching sheet metal combined with rolling (working sheet metal of limited length by stretching B21D25/00; by localised hammering B21D31/06) - B21D 25/00: Working sheet metal of limited length by stretching, e.g. for straightening - B21D 35/00: Combined processes according to {or processes combined with} methods covered by groups B21D1/00 - B21D31/00 (B21D21/00 takes precedence) - 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) ## Abstract A stretch-forming press for stamping continuously fed sheet metal includes a ram, a base member, and a feed mechanism configured to advance a strip of sheet metal through the stretch-forming press. A forming station has a die configured to form a desired pattern in the strip of sheet metal. A leveling station has a pair of opposed jaws slidably received in corresponding recesses of the stretch-forming press, with the jaws oriented at an angle with respect to a direction of travel for the strip of sheet metal as it passes through the leveling station. ## Claims ### Claim 1 A method of reducing distortion in a stamped sheet metal strip comprising the steps of: providing a stretch-forming press having a main forming station and a leveling station, the leveling station having a pair of jaws, each jaw being slidably received in a recess inclined at an acute angle with respective to a direction of travel of a strip of sheet metal through the stretch-forming press; stamping a desired pattern on the strip of sheet metal at the main forming station by closing the stretch-forming press; advancing the strip of sheet metal through the stretch-forming press in a direction of travel a desired distance such that the desired pattern is aligned with the leveling station; and closing the stretch-forming press such that the jaws of the leveling station engage the strip of sheet metal and stretch a portion of the strip of sheet metal containing the desired pattern in the direction of travel a selected distance as the jaws slide into the respective recesses when the stretch-forming press is closed. ### Claim 2 (depends on 1) The method of claim 1, wherein the acute angle and a resultant travel distance of the jaws along the recess are sized such that the selected distance is sufficient to counter effects of snap-back that result from stamping the desired pattern. ### Claim 3 (depends on 1) The method of claim 1, wherein the desired pattern comprises a plurality of channels. ### Claim 4 (depends on 1) The method of claim 1, further comprising the steps of: providing a pre-forming station in the stretch-forming press upstream, with respect to the direction of travel, of the main forming station; and stamping a pair of spaced apart channels in the strip of sheet metal at the pre-forming station. ### Claim 5 (depends on 4) The method of claim 4, wherein the distance between the spaced apart channels is the same distance as the desired distance. ### Claim 6 (depends on 4) The method of claim 4, wherein the step of stamping the spaced apart channels is performed by a pair of dies. ### Claim 7 (depends on 6) The method of claim 6, wherein each die is surrounded by a jaw biased into engagement with a base member of the stretch-forming press by a urethane rubber pad. ### Claim 8 (depends on 1) The method of claim 1, wherein the step of advancing the strip of sheet metal is performed by a pair of rollers. ### Claim 9 (depends on 1) The method of claim 1, further comprising the steps of: opening the stretch-forming press; advancing the strip of sheet metal through the stretch-forming press; repeating the steps of stamping a desired pattern, advancing the strip of sheet metal, closing the stretch-forming press, opening the stretch-forming press, and advancing the strip of sheet metal, a desired number of times to produce a strip of sheet metal having the desired pattern stamped continuously along its length. ### Claim 10 (depends on 9) The method of claim 9, further comprising the step of intermittently advancing the strip of sheet metal through the stretch-forming press a greater distance than that required to align the desired pattern with the leveling station when advancing the sheet metal strip from the main forming station to the leveling station in order to create a portion of the sheet metal strip along its length free of the desired pattern. ### Claim 11 A stretch-forming press for continuous feed sheet metal comprising, in combination: a ram; a base member; a forming station having a die configured to form a desired pattern in a strip of sheet metal; a leveling station having a pair of opposed jaws slidably received in corresponding recesses, the jaws oriented at an angle with respect to a direction of travel for a strip of sheet metal through the leveling station, the leveling station being positioned downstream of the forming station with respect to a strip of sheet metal passing through the forming station and the leveling station; and a feed mechanism configured to advance a strip of sheet metal through the forming station and the leveling station. ### Claim 12 (depends on 11) The stretch-forming press of claim 11, wherein the die is configured to produce a plurality of channels in a strip of sheet metal. ### Claim 13 (depends on 12) The stretch-forming press of claim 12, wherein each jaw of the forming station is biased toward the other jaw by a biasing member. ### Claim 14 (depends on 13) The stretch-forming press of claim 13, wherein each biasing member comprises a urethane rubber pad. ### Claim 15 (depends on 11) The stretch-forming press of claim 11, further comprising a pre-forming station having a pair of dies configured to form a pair of alignment recesses in the sheet metal strip. ### Claim 16 (depends on 15) The stretch-forming press of claim 15, wherein the alignment recesses are channels. ### Claim 17 (depends on 15) The stretch-forming press of claim 15, wherein each of the dies of the pre-forming station is surrounded by a jaw. ### Claim 18 (depends on 17) The stretch-forming press of claim 17, wherein each jaw of the pre-forming station is biased toward the base member by a biasing member. ### Claim 19 (depends on 18) The stretch-forming press of claim 18, wherein each biasing member of the pre-forming station comprises a urethane rubber pad. ### Claim 20 (depends on 11) The stretch-forming press of claim 11, wherein one jaw of the leveling station is slidably received in a recess of the base member and the other jaw of the leveling station is slidably received in a recess formed in a jaw housing. ### Claim 21 (depends on 11) The stretch-forming press of claim 11, wherein the angle is sized such that the jaws will stretch a portion of a strip of stamped sheet metal when the ram closes on the base member a distance sufficient to counter effects of snap-back that result from forming a desired pattern on a strip of sheet metal with the forming station. ### Claim 22 A stretch-forming press for continuous feed sheet metal comprising, in combination: a ram; a base member; a pre-forming station having a pair of spaced apart dies configured to mate with recesses formed in the base member to form alignment recesses in a strip of sheet metal to be shaped, each die being surrounded by a jaw, each jaw biased toward the base member by a biasing member; a main forming station having a pair of spaced apart jaws configured to mate with alignment recesses formed in a strip of sheet metal at the pre-forming station, each of the spaced apart jaws biased toward the base member by a biasing member, and a die configured to form a desired pattern in a strip of sheet metal passing through the main forming station; a leveling station having a pair of opposed jaws slidably received in corresponding recesses of the stretch-forming press, the jaws oriented at an angle with respect to a direction of travel for a strip of sheet metal passing through the leveling station and jaw biased toward the base member by a biasing member, the leveling station being positioned downstream of the pre-forming station and the main forming station with respect to a strip of sheet metal passing through the forming station and the leveling station; and a feed mechanism configured to advance a strip of sheet metal through the pre-forming station, the main forming station, and the leveling station. ### Claim 23 (depends on 22) The stretch-forming press of claim 22, wherein the alignment recesses are channels. ### Claim 24 (depends on 22) The stretch-forming press of claim 22, wherein each biasing member of the pre-forming station, the main forming station and the leveling station is a urethane rubber pad. ### Claim 25 (depends on 22) The stretch-forming press of claim 22, wherein the dies are configured to form a plurality of channels in a strip of sheet metal. ### Claim 26 (depends on 22) The stretch-forming press of claim 22, wherein the feed mechanism comprises a pair of rollers configured to cooperate to grip a strip of sheet metal and pull it through the stretch-forming press. ### Claim 27 (depends on 26) The stretch-forming press of claim 26, wherein one of the rollers is relieved in a central portion thereof. ### Claim 28 (depends on 22) The stretch-forming press of claim 22, wherein one jaw is slidably received in a recess of the base member and the other jaw is slidably received in a recess formed in a jaw housing. ### Claim 29 (depends on 22) The stretch-forming press of claim 22, wherein the angle is sized such that the jaws will stretch a portion of a strip of stamped sheet metal when the ram closes on the base member a distance sufficient to counter effects of snap-back that result from stamping a desired pattern on a strip of sheet metal with the forming station.