Stringer crawler with attachment mechanism

{
  "publication_number": "US2012114439A1",
  "country": "US",
  "kind": "A1",
  "title": "Stringer crawler with attachment mechanism",
  "abstract": "A crawler assembly includes an attachment mechanism that is removably attachable to a stringer. The stringer has a vertical web and a longitudinal axis. The crawler assembly includes a longitudinal slider that is engageable to the attachment mechanism and having a normalizing mechanism disposable in bearing contact against the vertical web for maintaining an orientation of the longitudinal slider relative to the stringer. The longitudinal slider is movable along a direction parallel to the longitudinal axis. The crawler assembly includes a lateral slider that is mountable to the longitudinal slider and is movable along a direction perpendicular to the longitudinal axis. The lateral slider includes a drill bushing. The longitudinal and lateral sliders cooperate to move the drill bushing to at least one predetermined hole location.",
  "claims": [
    "1. A crawler assembly engageable to a stringer having a vertical web and a longitudinal axis, comprising: an attachment mechanism removably attachable to the stringer; a longitudinal slider engageable to the attachment mechanism and having a normalizing mechanism disposable in bearing contact against the vertical web for maintaining an orientation of the longitudinal slider relative to the stringer, the longitudinal slider being operative to move in a direction parallel to the longitudinal axis; and a lateral slider mountable to the longitudinal slider and being movable in a direction perpendicular to the longitudinal axis, the lateral slider having a drill bushing mountable thereon; the longitudinal and lateral sliders cooperating to move the drill bushing to at least one predetermined hole location. 2. The crawler assembly of claim 1 wherein: the longitudinal slider has at least one clamping device for clamping the attachment mechanism to the stringer. 3. The crawler assembly of claim 1 wherein: each one of the longitudinal and lateral sliders includes at least one drive mechanism. 4. The crawler assembly of claim 3 further comprising: a controller configured to cause the drive mechanism to move the drill bushing toward the predetermined hole location. 5. The crawler assembly of claim 4 wherein: the controller is operative to index the drill bushing to a reference feature and cause the longitudinal and lateral sliders to move the drill bushing from the reference feature toward the predetermined hole location. 6. The crawler assembly of claim 1 wherein: the lateral slider is configured to move in a direction parallel to a plane defined by the vertical web and in a direction perpendicular to the longitudinal axis. 7. The crawler assembly of claim 1 wherein: the lateral slider is configured to move in a direction perpendicular to a plane defined by the vertical web and in a direction perpendicular to the longitudinal axis. 8. The crawler assembly of claim 1 further comprising: a normalizing mechanism for maintaining the crawler assembly into a predetermined orientation relative to the stringer. 9. The crawler assembly of claim 8 wherein: the normalizing mechanism comprises a pair of stringer rollers disposed on opposing sides of the vertical web. 10. A method of positioning a drill bushing at a predetermined hole location along a stringer, the method comprising the steps of: providing a crawler assembly having a normalizing mechanism and an attachment mechanism, the drill bushing being disposed on the crawler assembly; mounting the attachment mechanism to the stringer; mounting the crawler assembly to the attachment mechanism; placing the normalizing mechanism into contact with the stringer such that the crawler assembly is maintained in a predetermined orientation relative to the stringer; and driving the crawler assembly along the attachment mechanism such that the drill bushing is moved toward the predetermined hole location. 11. The method of claim 10 further comprising the steps of: indexing the drill bushing to a reference feature; and driving the crawler assembly toward the predetermined hole location based upon the reference feature."
  ],
  "description_excerpt": "The present disclosure relates generally to drilling fixtures and, more particularly, to a crawler assembly that is engageable to a stringer for drilling a pattern of holes.\n\nIn the production of various assemblies, a large quantity of fastener holes are typically drilled in mating parts in order to facilitate mechanical attachment of the various components. For example, during aircraft assembly operations, wing skin panels may be mechanically fastened to substructure such as stiffeners and stringers. Holes must be drilled at spaced intervals along the joint between the stringer and the panel to allow installation of the mechanical fasteners.\n\nThe drilling of such fastener holes must typically be performed with a high degree of precision with respect to locational tolerances of the holes as well as with respect to hole orientation and hole size. Because of the relatively high degree of precision required for such fastener holes, it is typically the practice to drill such holes using an alignment tool or assembly fixture. Conventional alignment tools or assembly fixtures typically includes a plurality of drill bushings located at spaced intervals along a hole pattern. The drill bushings maintain alignment of a drill motor that is used to drill each of the holes in the hole pattern.\n\nIn an aircraft assembly production line, various assembly fixtures are used during the overall assembly of each production unit. For example, during wing assembly, assembly tools may be used to perform manufacturing operations on the wing skin panels and substructure.",
  "cpc": [
    "B23B 47/28",
    "B23B 2215/04",
    "B23B 2247/12",
    "Y10T 408/03",
    "Y10T 408/556",
    "Y10T 408/5612",
    "Y10T 408/56245",
    "Y10T 408/563",
    "Y10T 408/567",
    "Y10T 408/892"
  ],
  "ipc": [
    "B23B 35/00",
    "B23B 49/02",
    "B23B 47/28"
  ],
  "assignees": [
    "Boeing Co"
  ],
  "inventors": [
    "James N. Buttrick",
    "Roger A. Gage",
    "Paul G. Kostenick, Jr.",
    "Jesus Sanchez",
    "Dario I. Valenzuela"
  ],
  "filing_date": "2011-12-20",
  "publication_date": "2012-05-10",
  "priority_date": "2008-09-02",
  "application_number": "US-201113330678-A",
  "family_id": "41725700",
  "cited_by_count": 9,
  "citations": [
    "US2083490A",
    "US2838966A",
    "US2949798A",
    "US3019675A",
    "US4599018A",
    "US4684299A",
    "US4850763A",
    "DE4218982A1",
    "US5308199A",
    "US5743684A",
    "US6796014B2",
    "US8100611B2"
  ]
}