Assembly system for monitoring proper fastening of an article of assembly at more than one location

• US 6,763,573 B2
• Filed: 11/19/2001
• Issued: 07/20/2004
• Est. Priority Date: 11/19/2001
• Status: Expired

• Current Assignee: Wildcat Licensing WI LLC (Wildcat Licensing LLC)
• Original Assignee: Lms-Walt, Inc.
• Inventors: Walt, Samuel A., Walt, II, Michael A.
• Primary Examiner(s): Bryant, David P.
• Assistant Examiner(s): Cozart, Jermie E.
• Application Number:
  US09/992,326
• Publication Number:
  US 20020032956A1
• Time in Patent Office: 974 Days
• Field of Search: 294/070.1, 294/070.2, 294/070.5, 294/070.9, 294/071, 295/25, 295/250.1, 295/251.1, 297/07, 297/08, 297/09, 297/12, 297/14, 297/20, 297/21, 297/87, 297/95, 298/22, 298/24, 292/435, 292/70, 292/40, 470/1, 470/2, 738/620.8, 738/622.1, 738/622.3, 173/5, 173/6, 173/180, 173/81
• US Class Current: 29/707
• CPC Class Codes: B23P 19/066 by electrical means
• CPC Class Codes: B25B 23/14 Arrangement of torque limiters or torque indicators in wrenches or screwdrivers couplings for transmitting rotation or clutches F16D; devices for measuring torque per se G01L
• CPC Class Codes: B25H 1/0021 Stands, supports or guiding devices for positioning portable tools or for securing them to the work B23B41/00 takes precedence
• CPC Class Codes: B25H 1/0028 Tool balancers
• CPC Class Codes: G05B 2219/37459 Reference on workpiece, moving workpiece moves reference point
• CPC Class Codes: G05B 2219/37555 Camera detects orientation, position workpiece, points of workpiece
• CPC Class Codes: G05B 2219/45022 Auto seat, dentist chair, roll wheel chair
• CPC Class Codes: Y10T 29/49719 Seal or element thereof
• CPC Class Codes: Y10T 29/49766 torquing threaded assemblage or determining torque herein
• CPC Class Codes: Y10T 29/49769 Using optical instrument [excludes mere human eyeballing]
• CPC Class Codes: Y10T 29/49771 Quantitative measuring or gauging
• CPC Class Codes: Y10T 29/4978 Assisting assembly or disassembly
• CPC Class Codes: Y10T 29/49947 by applying separate fastener
• CPC Class Codes: Y10T 29/5303 Responsive to condition of work or product
• CPC Class Codes: Y10T 29/53039 with control means energized in response to activator stimulated by condition sensor
• CPC Class Codes: Y10T 29/53052 including position sensor
• CPC Class Codes: Y10T 29/53074 with means to fasten by elastic joining
• CPC Class Codes: Y10T 29/53087 with signal, scale, illuminator, or optical viewer
• CPC Class Codes: Y10T 29/53091 for work-holder for assembly or disassembly
• CPC Class Codes: Y10T 29/53383 and means to fasten work parts together
• CPC Class Codes: Y10T 29/53417 : Means to fasten work parts together
• CPC Class Codes: Y10T 29/53548 : and work carrying vehicle

Abstract

A more reliable and fool-proof method and apparatus for assembling an article of assembly (e.g. with predetermined screw torque requirements) in which the article of assembly has multiple fastening locations. The method comprises holding the article of assembly fixed while providing at least two different types of targets fixed relative to the article of assembly that correspond to the individual fastening locations. Fasteners are fastened into the article of assembly at the fastening locations. When fastening is occurring at one of the fastening locations, one of the targets is being sensed. Based on the target sensed, a target output is generated that differentiates between different types of targets thereby indicating fastening location of the fastening tool. The electronic target output is used for electronic control such as for stopping a conveyor to keep the article of assembly at an assembly station until the fastening operations have been completed.

Claims

1. An assembly system for assembling articles of assembly, each article of assembly having a plurality of fastening locations including at least first and second fastening locations in spaced apart relation, comprising:

a fixture holding the article of assembly;

a plurality of targets including at least a first target fixed relative to the fixture, corresponding to the first fastening location, and a second target fixed relative to the fixture, the second target corresponding to the second fastening location, the second target having a different characteristic than the first target;

a fastening tool adapted to fasten fasteners into the article of assembly at the first and second fastening locations, the fastening tool having a first position relative to the fixture in which the fastening tool is in position to fasten a fastener at the first location, and a second position relative to the fixture in which the fastening tool is in position to fasten a fastener at the second location;

a target sensor fixed relative to the fastening tool along at least one axis, the target sensor sensing the first target when the fastening tool is in the first position, the target sensor sensing the second target when the fastening tool is in the second position, the target sensor providing a target output differentiating between the first and second targets and indicating when the fastening tool is in either of the first fastening location and the second fastening location; and

an electronic controller in communication with the target sensor utilizing said target output to check a quality characteristic of manual fastening operations facilitated by the fastening tool at the plurality of fastening locations, wherein the fastening tool moves independent of the electronic controller and is not controllably positioned thereby.

2. The assembly system of claim 1 wherein the fixture is carried by a conveyor, the fastening tool being movable relative to the conveyor.

3. The assembly system of claim 2 further comprising an assembly station along the conveyor, the fixture being conveyed on the conveyor to the assembly station where the fixture is intermittently stopped by a stop mechanism for fastening by the fastening tool, further comprising an electronic controller in communication with the target sensor, the electronic controller monitoring the location of the fastening tool to ensure proper fastening of fasteners at the fastening locations.

4. The assembly system of claim 2 further comprising an assembly station along the conveyor, the conveyor transporting the fixtures through the assembly station substantially without stopping on a continuous basis.

5. The assembly system of claim 4 comprising at least two types of the fixtures and at least two types of first and second targets for the at least two types of the fixtures, respectively, wherein the target sensor provides said target output that also differentiates between the at least two types of first and second targets, further comprising an electronic controller in communication with the target sensor, the electronic controller monitoring the location of the fastening tool and determining the fixture being serviced by the fastening tool to ensure proper fastening of fasteners at the fastening locations on articles of assembly held by each fixture.

6. The assembly system of claim 2 wherein the sensor comprises a laser and laser sensing device, the fastening tool being movable in a plane spaced from the article of assembly held in the fixture to selectively position the fastening tool at the first and second fastening locations, the laser and laser sensing device being movable with the fastening tool in said plane, the first and second targets comprising reflective material spaced at different distances perpendicular to said plane.

7. The assembly system of claim 1 further comprising an electronic controller in electrical communication with the target sensor and the fastening tool, the electronic controller enabling the fastening tool when the target sensor is in sensory communication with one of the targets and disabling the fastening tool when target sensor is not in sensory communication with one of the targets.

8. The assembly system of claim 1 wherein the target sensor comprises a machine vision camera and wherein the first and second targets have different visual characteristics, wherein electronic controller an is in communication with the machine vision camera differentiating between the different visual characteristic to determine the location of the fastening tool.

9. The assembly system of claim 8 wherein the fasteners are spaced horizontally and vertically according to a predetermined spacing, the first and second targets being spaced horizontally and vertically according to the predetermined spacing, the fastening tool being movable along vertical and horizontal axes relative to the fixture.

10. The assembly system of claim 8 wherein the characteristics of the first and second targets are selected from the group consisting of geometric shapes, colors and alphanumeric characters.

11. The assembly system of claim 1 wherein the articles of assembly comprise an automotive seat comprised of at least two parts, the fasteners comprising threaded fasteners for fastening the at least two parts together.

12. The assembly system of claim 1, wherein the first and second targets are separate from and not part of the article of assembly.

25. The assembly system of claim 1 wherein the fixture is carried by a conveyor, the fastening tool being movable relative to the conveyor, further comprising an assembly station along the conveyor, the fixture being conveyed on the conveyor to the assembly station where the fixture is intermittently stopped by a stop mechanism for fastening by the fastening tool, wherein the electronic controller releases the stop mechanism when the predetermined sequence has been achieved thereby allowing the fixture to be conveyed on the conveyor.

13. An assembly system for assembling articles of assembly, each article of assembly having a plurality of fastening locations including at least first and second fastening locations in spaced apart relation, comprising:

a fixture holding the article of assembly;

a plurality of targets including at least a first target fixed relative to the fixture, corresponding to the first fastening location, and a second target fixed relative to the fixture, the second target corresponding to the second fastening location, the second target having a different characteristic than the first target;

a fastening tool adapted to fasten fasteners into the article of assembly at the first and second fastening locations, the fastening tool having a first position relative to the fixture in which the fastening tool is in position to fasten a fastener at the first location, and a second position relative to the fixture in which the fastening tool is in position to fasten a fastener at the second location;

a target sensor fixed relative to the fastening tool along at least one axis, the target sensor sensing the first target when the fastening tool is in the first position, the target sensor sensing the second target when the fastening tool is in the second position, the target sensor providing a target output differentiating between the first and second targets and indicating when the fastening tool is in either of the first fastening location and the second fastening location;

wherein the fixture is carried by a conveyor, the fastening tool being movable relative to the conveyor, further comprising an assembly station along the conveyor, the fixture being conveyed on the conveyor to the assembly station where the fixture is intermittently stopped by a stop mechanism for fastening by the fastening tool, further comprising an electronic controller in communication with the target sensor, the electronic controller monitoring the location of the fastening tool to ensure proper fastening of fasteners at the fastening locations; and

wherein the electronic controller controls the stop mechanism, the electronic controller maintaining the fixture at the assembly station and not releasing the fixture for movement on the conveyor out of the assembly station until the fastening tool has properly fastened fasteners into the article of assembly at the fastening locations.

14. An assembly system for assembling articles of assembly, each article of assembly having a plurality of fastening locations including at least first and second fastening locations in spaced apart relation, comprising:

a fixture holding the article of assembly;

a plurality of targets including at least a first target fixed relative to the fixture, corresponding to the first fastening location, and a second target fixed relative to the fixture, the second target corresponding to the second fastening location, the second target having a different characteristic than the first target;

a fastening tool adapted to fasten fasteners into the article of assembly at the first and second fastening locations, the fastening tool having a first position relative to the fixture in which the fastening tool is in position to fasten a fastener at the first location, and a second position relative to the fixture in which the fastening tool is in position to fasten a fastener at the second location;

a target sensor fixed relative to the fastening tool along at least one axis, the target sensor sensing the first target when the fastening tool is in the first position, the target sensor sensing the second target when the fastening tool is in the second position, the target sensor providing a target output differentiating between the first and second targets and indicating when the fastening tool is in either of the first fastening location and the second fastening location;

an electronic controller in communication with the target sensor, the electronic controller monitoring the location of the fastening tool to ensure proper fastening of fasteners at the fastening locations;

wherein the fixture is carried by a conveyor, the fastening tool being movable relative to the conveyor, further comprising an assembly station along the conveyor, the fixture being conveyed on the conveyor to the assembly station where the fixture is intermittently stopped by a stop mechanism for fastening by the fastening tool; and

wherein the fasteners are threaded fasteners, the fastening tool having a torque monitor, the torque monitor providing an indication to the electronic controller of torque applied to the fasteners, the electronic controller having predetermined torque values for at least one of the fastening locations, the electronic controller determining the location of the fastening tool that corresponds to the indication of torque and providing an output indicating whether the predetermined torque values for at least one of the fastening locations have been reached.

15. The assembly system of claim 14 wherein the electronic controller releases the stop mechanism when the predetermined torque values have been reached thereby allowing the fixture to be conveyed on the conveyor.

16. An assembly system for assembling articles of assembly, each article of assembly having a plurality of fastening locations including at least first and second fastening locations in spaced apart relation, comprising:

a fixture holding the article of assembly;

a plurality of targets including at least a first target fixed relative to the fixture, corresponding to the first fastening location, and a second target fixed relative to the fixture, the second target corresponding to the second fastening location, the second target having a different characteristic than the first target;

a fastening tool adapted to fasten fasteners into the article of assembly at the first and second fastening locations, the fastening tool having a first position relative to the fixture in which the fastening tool is in position to fasten a fastener at the first location, and a second position relative to the fixture in which the fastening tool is in position to fasten a fastener at the second location;

a target sensor fixed relative to the fastening tool along at least one axis, the target sensor sensing the first target when the fastening tool is in the first position, the target sensor sensing the second target when the fastening tool is in the second position, the target sensor providing a target output differentiating between the first and second targets and indicating when the fastening tool is in either of the first fastening location and the second fastening location;

an electronic controller in communication with the target sensor, the electronic controller monitoring the location of the fastening tool to ensure proper fastening of fasteners at the fastening locations; and

wherein the fastening tool comprises a fastening monitor indicating a fastening operation, wherein the electronic controller has a predetermined sequence program requiring a predetermined sequence of fastening among the fastening locations, the electronic controller-monitoring the sequence of fastening based upon the target output, the electronic controller providing an output indicating whether the predetermined sequence has been achieved.

17. The assembly system of claim 16, wherein the fixture is carried by a conveyor, the fastening tool being movable relative to the conveyor, further comprising an assembly station along the conveyor, the fixture being conveyed on the conveyor to the assembly station where the fixture is intermittently stopped by a stop mechanism for fastening by the fastening tool, wherein the electronic controller releases the stop mechanism when the predetermined sequence has been achieved thereby allowing the fixture to be conveyed on the conveyor.

18. An assembly system for assembling articles of assembly, each article of assembly having a plurality of fastening locations including at least first and second fastening locations in spaced apart relation, comprising:

a fixture holding the article of assembly;

a plurality of targets including at least a first target fixed relative to the fixture, corresponding to the first fastening location, and a second target fixed relative to the fixture, the second target corresponding to the second fastening location, the second target having a different characteristic than the first target;

a fastening tool adapted to fasten fasteners into the article of assembly at the first and second fastening locations, the fastening tool having a first position relative to the fixture in which the fastening tool is in position to fasten a fastener at the first location, and a second position relative to the fixture in which the fastening tool is in position to fasten a fastener at the second location;

a target sensor fixed relative to the fastening tool along at least one axis, the target sensor sensing the first target when the fastening tool is in the first position, the target sensor sensing the second target when the fastening tool is in the second position, the target sensor providing a target output differentiating between the first and second targets and indicating when the fastening tool is in either of the first fastening location and the second fastening location;

where in the fixture is carried by a conveyor, the fastening tool being movable relative to the conveyor, and further comprising an assembly station along the conveyor, the conveyor transporting the fixtures through the assembly station substantially without stopping on a continuous basis; and

wherein the assembly station has an input location receiving fixtures from an upstream station and an output location delivering fixtures to a downstream station, the fastening tool being movable horizontally along the conveyor between the input location and the output location, further comprising a fixture sensor in communication with fixtures passing through the assembly station, the fixture sensor having a fixture position output indicating when fixtures have exited the assembly station through the output location, an electronic controller in communication with the fixture sensor, the electronic controller outputting an alarm signal when one of the fixtures has exited the assembly station without proper fastening of fasteners at the fastening locations.

19. The assembly system of claim 18, wherein the fasteners are threaded fasteners, the fastening tool having a torque monitor, the torque monitor providing an indication to the electronic controller of torque applied to the fasteners, the electronic controller having predetermined torque values for at least one of the fastening locations, the electronic controller determining the location of the fastening tool that corresponds to the indication of torque and providing an output indicating whether the predetermined torque values for at least one of the fastening locations have been reached.

20. The assembly system of claim 19 wherein the fastening tool comprises a fastening monitor indicating a fastening operation, wherein the electronic controller has a predetermined sequence program requiring a predetermined sequence of fastening among the fastening locations, the electronic controller controlling the sequence of fastening based upon the target output, the electronic controller providing an output indicating whether the predetermined sequence has been achieved.

21. An assembly system for assembling articles of assembly, each article of assembly having a plurality of fastening locations including at least first and second fastening locations in spaced apart relation, comprising:

a fixture holding the article of assembly;

a plurality of targets including at least a first target fixed relative to the fixture, corresponding to the first fastening location, and a second target fixed relative to the fixture, the second target corresponding to the second fastening location, the second target having a different characteristic than the first target;

a fastening tool adapted to fasten fasteners into the article of assembly at the first and second fastening locations, the fastening tool having a first position relative to the fixture in which the fastening tool is in position to fasten a fastener at the first location, and a second position relative to the fixture in which the fastening tool is in position to fasten a fastener at the second location;

a target sensor fixed relative to the fastening tool along at least one axis, the target sensor sensing the first target when the fastening tool is in the first position, the target sensor sensing the second target when the fastening tool is in the second position, the target sensor providing a target output differentiating between the first and second targets and indicating when the fastening tool is in either of the first fastening location and the second fastening location; and

wherein the fasteners are threaded fasteners, the fastening tool having a torque monitor, the torque monitor providing an indication to an electronic controller of torque applied to the fasteners, the electronic controller having predetermined torque values for at least one of the fastening locations, the electronic controller determining the location of the fastening tool that corresponds to the indication of torque and providing an output indicating whether the predetermined torque values for at least one of the fastening locations have been reached.

22. An assembly system for assembling articles of assembly, each article of assembly having a plurality of fastening locations including at least first and second fastening locations in spaced apart relation, comprising:

a fixture holding the article of assembly;

a plurality of targets including at least a first target fixed relative to the fixture, corresponding to the first fastening location, and a second target fixed relative to the fixture, the second target corresponding to the second fastening location, the second target having a different characteristics than the first target;

a fastening tool adapted to fasten fasteners into the article of assembly at the first and second fastening locations, the fastening tool having a first position relative to the fixture in which the fastening tool is in position to fasten a fastener at the first location, and a second position relative to the fixture in which the fastening tool is in position to fasten a fastener at the second location;

a target sensor fixed relative to the fastening tool along at least one axis, the target sensor sensing the first target when the fastening tool is in the first position, the target sensor sensing the second target when the fastening tool is in the second position, the target sensor providing a target output differentiating between the first and second targets and indicating when the fastening tool is in either of the first fastening location and the second fastening location; and

wherein the fastening tool plunges along a fastening axis perpendicular to said plane, the laser and laser sensing device remaining stationary during plunging of the fastening tool.

23. The assembly system of claim 22 wherein the fixture is carried by a conveyor, the fastening tool being movable horizontally relative to the conveyor, the laser and laser sensing device being restricted to horizontal movement along a horizontal axis along with the fastening tool, further comprising a reflective panel extending in the horizontal axis in reflective communication with the laser and laser sensing device with a reflective surface aligned at an oblique angle relative to said plane.

24. An assembly system for assembling articles of assembly, each article of assembly having a plurality of fastening locations including at least first and second fastening locations in spaced apart relation, comprising:

a fixture holding the article of assembly;

a fastening tool adapted to fasten fasteners into the article of assembly at the first and second fastening locations, the fastening tool having a first position relative to the fixture in which the fastening tool is in position to fasten a fastener at the first location, and a second position relative to the fixture in which the fastening tool is in position to fasten a fastener at the second location;

at least one sensor providing a sensor output indicating when the fastening tool is the first and second fastening locations;

an electronic controller in communication with the at least one sensor, the electronic controller monitoring the location of the fastening tool to ensure proper fastening of fasteners at the fastening locations; and

wherein the fastening tool comprises a fastening monitor indicating a fastening operation, wherein the electronic controller has a predetermined sequence program requiring a predetermined sequence of fastening among the fastening locations, the electronic controller monitoring the sequence of fastening based upon the sensor output, the electronic controller providing an output indicating whether the predetermined sequence has been achieved.