Patent US4916284A successfully refreshed from Google Patents.
US4916284A
Expired / Lapsed
US
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Method of making hemmed joints utilizing laser welding
Assignee: Motors Liquidation Co
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Filing: 1989-05-08
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Granted: 1990-04-10
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Expires: 2009-05-08
Abstract
Abstract Methods of laser welding zinc coated galvalized steel are disclosed. In a method that relates to forming hem joints for motor vehicle body components a sheet of steel is provided with a plurality of V-shaped tabs. When a hem joint is formed the V-shaped tabs together with a surface of another sheet of steel form gas venting channels that provide an escape passage for gas vapors that are developed when the zinc coating is vaporized by laser welding. In another method of laser welding, one of the steel sheets has an axially extending wall that is V-shaped to provide a V-shaped groove and the wall has spaced gas vent holes.
Inventors
- 👤 Frederick D. Petrick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 05:35
CPC Classifications
B; B23; B23K; B23K33/00; B23K33/004; B23K33/008; B23K26/00; B23K26/16; B23K26/20; B23K26/21; B23K26/24; B23K26/244; B23K26/32; B23K26/60; B23K2101/00; B23K2101/006; B23K2101/34; B23K2103/00; B23K2103/02; B23K2103/04; B23K2103/08; B23K2103/50; B29; B29C; B29C66/00; B29C66/01; B29C66/05; B29C66/10; B29C66/13; B29C66/135; B29C66/302; B29C66/3022; B29C66/30223
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
207 words
A method of making a hem joint between two sheets of steel that have a corrosion protective metallic zinc coating, the steps comprising, forming a first sheet of steel into a configuration that has a hem flange portion which carries a plurality of spaced tab portions that extend from said flange portion, forming each tab portion to define a groove, folding said hem flange portion and said tabs around a marginal portion of a second sheet of steel to form a hem joint, said hem joint being defined by said hem flange portion and a portion of said first sheet with said marginal portion of said second sheet disposed therebetween, the wall of said tab that defines said groove and a portion of said second steel sheet said that faces said wall defining a gas vent channel which is open to the atmosphere at opposite ends of a tab portion, and then directing a laser beam sequentially to each tab portion at a point aligned with a said channel to create a weld zone of molten metal that connects a tab portion to a portion of said second sheet, said channel providing a path for the escape of gas developed by the vaporizing of said zinc coating.
Claim 2
Independent Claim
207 words
A method of making a hem joint between two sheets of steel that have a corrosion protective metallic zinc coating, the steps comprising, forming a first sheet of steel into a configuration that has a hem flange portion which carries a plurality of spaced tab portions that extend from said flange portion, forming each tab portion to define a groove, folding said hem flange portion and said tabs around a marginal portion of a second sheet of steel to form a hem joint, said hem joint being defined by said hem flange portion and a portion of said first sheet with said marginal portion of said second sheet disposed therebetween, the wall of said tab that defines said groove and a portion of said second steel sheet said that faces said wall defining a gas vent channel which is open to the atmosphere at opposite ends of a tab portion, and then directing a laser beam sequentially to each tab portion at a point aligned with a said channel to create a weld zone of molten metal that connects a tab portion to a portion of said second sheet, said channel providing a path for the escape of gas developed by the vaporizing of said zinc coating.
Claim 3
Dependent Claim
11 words
The method according to claim 1 where said groove is V-shaped.
Claim 4
Dependent Claim
18 words
The method according to claim 1 where said groove has a maximum depth of 0.005 to 0.012 inches.
Claim 5
Dependent Claim
47 words
The method according to claim 1 where an adhesive is applied to a surface of said marginal portion of said second sheet prior to said folding of said hem flange, said adhesive after folding providing a sealed hem joint, said tabs being disposed inside of said adhesive.
Claim 6
Dependent Claim
24 words
The method according to claim 1 where both sides of said first and second steel sheets are coated with a thin layer of zinc.
Claim 7
Dependent Claim
32 words
The method according to claim 1 where the length of said weld zone is such that no weld imperfection is formed on an exterior surface of said first portion of said sheet.
Claim 8
Dependent Claim
21 words
The method according to claim 1 where no portion of said weld zone penetrates into said portion of said first sheet.
Claim 9
Independent Claim
149 words
The method of laser welding two sheets of steel that have a corrosion protective metallic zinc coating, the steps comprising, forming a first sheet of steel into a configuration that has a wall defining an axially extending groove, said wall having a plurality of spaced holes extending therethrough defining gas vents, placing said first, sheet of steel against a flat portion of a second sheet of steel whereby a portion of said flat portion that faces said groove and said wall define an axially extending channel that is open at its ends and is open to said spaced holes, and then directing a laser beam to lengths of said wall disposed between said holes to thereby laser weld said lengths to said second sheet of steel, said channel and holes operative to provide paths for the escape of gases developed by vaporization of said zinc coating during laser welding.
Claim 10
Independent Claim
149 words
The method of laser welding two sheets of steel that have a corrosion protective metallic zinc coating, the steps comprising, forming a first sheet of steel into a configuration that has a wall defining an axially extending groove, said wall having a plurality of spaced holes extending therethrough defining gas vents, placing said first, sheet of steel against a flat portion of a second sheet of steel whereby a portion of said flat portion that faces said groove and said wall define an axially extending channel that is open at its ends and is open to said spaced holes, and then directing a laser beam to lengths of said wall disposed between said holes to thereby laser weld said lengths to said second sheet of steel, said channel and holes operative to provide paths for the escape of gases developed by vaporization of said zinc coating during laser welding.
Claim 11
Dependent Claim
11 words
The method according to claim 8 where the groove is v-shaped.
References Cited (Backward Citations)
US4386728A
Cited
EP0157913A1
Cited
JPS6127189A
Cited
US4682002A
Cited
US4684775A
Cited
US4719689A
Cited
FR2600923A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-04-09 | 1993-10-09 | 1994-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-09 | 1997-10-09 | 1998-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-09 | 2001-10-09 | 2002-04-10 | $7700.00 | Window Closed / Lapsed |