Title:
INTEGRAL CLAMPING-AND-BUCKING APPARATUS FOR UTILIZING A CONSTANT FORCE AND INSTALLING RIVET FASTENERS IN A SHEET METAL JOINT
Kind Code:
A1


Abstract:
One advantageous embodiment of the present invention is an integral clamping-and-bucking apparatus (12) for a system (10), which is utilized for applying rivet fasteners (56) to two or more panels (14a, 14b) and forming a joint (24) therebetween. The integral clamping-and-bucking apparatus (16) includes a clamping foot (46) for clamping the panels (14a, 14b) in a predetermined configuration and for drilling a hole (54) in the panels (14a, 14b) the panels (14a, 14b) at the joint (24). Also, the integral clamping-and-bucking apparatus (12) further includes a bucking bar (48) for bucking a rivet tail (62) that extends from the hole (54). The clamping foot (46) and the bucking bar (48) are coupled to and actuated by a controller (32). This controller (32) actuates the bucking bar (48) and the clamping foot (46) for transferring power between the clamping foot (32) and the bucking bar (48) while maintaining a substantially constant total force applied to the panels (14a, 14b).



Inventors:
Ffield, Paul E. (Marysville, WA, US)
Coffland, Donald W. (Seattle, WA, US)
Application Number:
10/904978
Publication Date:
06/08/2006
Filing Date:
12/08/2004
Assignee:
THE BOEING COMPANY (Chicago, IL, US)
Primary Class:
Other Classes:
29/796, 29/243.53
International Classes:
B21J15/02
View Patent Images:
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Primary Examiner:
KOEHLER, CHRISTOPHER M
Attorney, Agent or Firm:
OSTRAGER CHONG FLAHERTY & BROITMAN, P.C. (NEW YORK, NY, US)
Claims:
What is claimed is:

1. An integral clamping-and-bucking apparatus for a system that is utilized for applying rivet fasteners to at least two components and forming a joint between those components, comprising: a clamping foot for applying a clamping force to the components and securing the components in a predetermined configuration for drilling a hole in the components at the joint; a bucking bar for applying a bucking force to a rivet disposed within said hole so as to couple the components at the joint; and a controller coupled to said clamping foot for actuating said clamping foot to apply said clamping force to the components, said controller also coupled to said bucking bar for actuating said bucking bar to apply said bucking force to said rivet and said components; wherein a sum of said clamping force and said bucking force comprise a total force; wherein said controller regulates said clamping force and said bucking force and maintains a substantially constant total force applied to the components.

2. The integral clamping-and-bucking apparatus as recited in claim 1 further comprising: a motor coupled between said controller and said clamping foot for actuating said clamping foot to apply said clamping force to the components.

3. The integral clamping-and-bucking apparatus as recited in claim 2 wherein said motor is selected from the group consisting of a pneumatically-driven mechanism, an electrically-driven servo mechanism, a screw mechanism, and a pulley mechanism.

4. The integral clamping-and-bucking apparatus as recited in claim 1 further comprising: a motor coupled between said controller and said clamping foot for actuating said clamping foot to apply said clamping force to the components.

5. The integral clamping-and-bucking apparatus as recited in claim 4 wherein said motor is selected from the group consisting of a pneumatically-driven mechanism, an electrically-driven servo mechanism, a screw mechanism, and a pulley mechanism.

6. An integral clamping-and-bucking apparatus for a system that is utilized for applying rivet fasteners to at least two panels and forming a joint between those panels, comprising: a base member that is movable substantially along the panels; a clamping foot coupled to said base member, said clamping foot having a substantially concentric construction for applying a clamping force to the panels and securing the panels in a predetermined configuration for drilling a hole in the panels at the joint and riveting the panels at the joint; a bucking bar slidably disposed within said base member for applying a bucking force to a rivet disposed within said hole so as to couple the panels at the joint; and a controller coupled to said clamping foot and said bucking bar for actuating said clamping foot to apply said clamping force to the panels and said bucking bar to apply said bucking force to said rivet; wherein said controller applies a substantially constant total force to the panels, said substantially constant total force being comprised of said clamping force and said bucking force that is applied to the panels via said rivet.

7. The integral clamping-and-bucking apparatus as recited in claim 6 wherein said base member has an end portion with a channel formed therethrough, said channel for passing said bucking bar therethrough and installing said rivet in the panels within said hole.

8. The integral clamping-and-bucking apparatus as recited in claim 7 wherein said clamping foot substantially surrounds said channel for applying substantially evenly distributed force to the panels adjacent to said hole.

9. The integral clamping-and-bucking apparatus as recited in claim 8 wherein said clamping foot has a ring construction.

10. The integral clamping-and-bucking apparatus as recited in claim 6 wherein said clamping foot is comprised of an elastic material.

11. The integral clamping-and-bucking apparatus as recited in claim 6 wherein said clamping foot is comprised of a polyurethane material.

12. The integral clamping-and-bucking apparatus as recited in claim 6 further comprising: a carrier member having said base member mounted thereon for moving said base member along at least one axis; wherein said carrier member is located in a fixed position when said controller decreases said clamping force and increases said bucking force.

13. A system for applying rivet fasteners to at least two panels for forming a joint between those panels, comprising: an integral clamping-and-bucking apparatus disposed on a first side of the joint and comprising a clamping foot and a bucking bar, said clamping foot for applying a clamping force to the panels and securing the panels in a predetermined configuration for drilling a hole in the panels at the joint and riveting the panels at the joint, said bucking bar for applying a bucking force to a rivet disposed within said hole so as to couple the panels at the joint; an integral drilling-and-riveting apparatus disposed on a second side of the joint and comprising a drilling device and a riveting device, said drilling device for drilling said hole in the panels, said riveting device for applying an impulse force to said rivet; and a controller coupled to said clamping foot for actuating said clamping foot to apply said clamping force to the panels, said controller also coupled to said bucking bar for actuating said bucking bar to apply said bucking force to said rivet; wherein said controller applies a substantially constant total force to the panels, said substantially constant total force being comprised of said clamping force and said bucking force.

14. The system as recited in claim 13 wherein said integral drilling-and-riveting apparatus further includes an indexing foot for positioning the panels in said predetermined configuration.

15. The system as recited in claim 16 wherein said indexing foot and said clamping foot sandwich the panels therebetween in said predetermined configuration.

16. The system as recited in claim 16 wherein said indexing foot is coupled to and actuated by said controller.

17. The system in claim 13 wherein said indexing foot has a ring construction for substantially surrounding said hole for applying a substantially evenly distributed force to the panels adjacent to said hole.

18. The system in claim 13 wherein said clamping foot has a ring construction.

19. The system in claim 13 wherein said clamping foot is comprised of an elastic material for deforming against the panels and normalizing the panels against said indexing foot for positioning the panels in said predetermined position.

20. The system in claim 19 wherein said clamping foot is comprised of a polyurethane material.

21. The system in claim 13 further comprising: a motor coupled between said controller and said clamping foot for actuating said clamping foot to apply said clamping force to the panels.

22. The system in claim 21 wherein said motor is selected from the group consisting of a pneumatically-driven mechanism, an electrically-driven servo mechanism, a screw mechanism, and a pulley mechanism.

23. The system in claim 13 further comprising: a motor coupled between said controller and said clamping foot for actuating said clamping foot to apply said clamping force to the panels.

24. The system in claim 23 wherein said motor is selected from the group consisting of a pneumatically-driven mechanism, an electrically-driven servo mechanism, a screw mechanism, and a pulley mechanism.

25. A system for applying rivet fasteners to at least two panels and forming a joint between those panels, comprising: an integral clamping-and-bucking apparatus disposed on a first side of the joint of an airframe, said integral clamping bucking apparatus comprising a base member, a clamping foot coupled to said base member, and a bucking bar slidably coupled to said base member, said clamping foot having a substantially concentric construction for applying a clamping force to the panels and securing the panels in a predetermined configuration for drilling a hole in the panels at the joint and riveting the panels at the joint, said bucking bar for applying a bucking force to a rivet disposed within said hole so as to couple the panels at the joint; an integral drilling-and-riveting apparatus disposed on a second side of the joint and comprising a drilling device and a riveting device, said drilling device for drilling said hole in the panels, said riveting device for applying an impulse force to said rivet; and a controller coupled to said clamping foot for actuating said clamping foot to apply said clamping force to the panels, said controller also coupled to said bucking bar for actuating said bucking bar to apply said bucking force to said rivet; wherein said controller applies a substantially constant total force to the panels, said substantially constant total force being comprised of said clamping force and said bucking force.

26. The system in claim 25 wherein said base member has an end portion with a channel formed therethrough, said channel for passing said bucking bar therethrough.

27. The system in claim 26 wherein said clamping foot substantially surrounds said channel for applying substantially evenly distributed force to the panels adjacent to said hole.

28. The system in claim 25 wherein said clamping foot has a ring construction.

29. The system in claim 25 wherein said clamping foot is comprised of an elastic material for deforming against the panels and normalizing the panels against said indexing foot for positioning the panels in said predetermined configuration.

30. The system in claim 29 wherein said clamping foot is comprised of a polyurethane material.

31. The system in claim 25 further comprising: an airframe structure for mounting the panels thereon.

32. The system in claim 25 further comprising: at least one rail coupled to the panels for mounting said integral drilling-and-riveting apparatus thereon.

33. The system in claim 25 wherein said integral clamping-and-bucking apparatus further comprises: a carrier member having said base member mounted thereon for moving said base member along at least one axis on said first side of the joint; wherein said carrier member is located in a fixed position when said controller decreases said clamping force and increases said bucking force.

34. The system in claim 25 wherein said integral drilling-and-riveting apparatus further comprises: a guide member having said drilling device and said riveting device mounted thereon for moving said drilling device and said riveting device along at least one axis on said second side of the joint.

35. A method for applying rivet fasteners to at least two panels and forming a joint between those panels, comprising: positioning an integral clamping-and-bucking apparatus in a first predetermined position on a first side of the panels, said integral clamping-and-bucking apparatus including a clamping foot and a bucking bar that is slidably coupled to said clamping foot; actuating said clamping foot for applying a clamping force to the panels and securing the panels in a predetermined configuration for drilling a hole in the panels at the joint and riveting the panels at the joint; decreasing said clamping force by a predetermined amount; increasing said bucking force by about said predetermined amount; applying a substantially constant total force that is applied to the panels, said substantially constant total force being comprised of said clamping force and said bucking force.

36. The system as recited in claim 35 further comprising: mounting the panels to a frame in said predetermined configuration; positioning an integral drilling-and-riveting apparatus in said first predetermined position on a second side of the panels; actuating said integral drilling-and-riveting apparatus to drill said hole in the panels; inserting a blank rivet in said hole; actuating said integral drilling-and-riveting apparatus and said integral clamping-and-bucking apparatus to install said rivet in the panels within said hole; unclamping the panels; positioning said integral clamping-and-bucking apparatus in a second predetermined position on a first side of the joint between the panels; positioning an integral drilling-and-riveting apparatus in said second predetermined position on a second side of the joint between the panels.

37. The method as recited in claim 36 further comprising: positioning an indexing foot of said integral drilling-and-riveting apparatus in said first predetermined position on said second side of the panels; and actuating a clamping foot of said integral clamping-and-bucking apparatus to force the panels against said indexing foot.

38. The method as recited in claim 37 wherein actuating said clamping foot comprises: deforming said clamping foot against the panels and normalizing the panels on said indexing foot for positioning the panels in said predetermined configuration.

39. A method for manufacturing an airframe, comprising: mounting at least two airframe components on a frame in a predetermined configuration; positioning an integral clamping-and-bucking apparatus in a first predetermined position on a first side of the panels, said integral clamping-and-bucking apparatus including a clamping foot and a bucking bar that is slidably coupled to said clamping foot; positioning an integral drilling-and-riveting apparatus in said first predetermined position on a second side of the panels; said integral drilling-and-riveting apparatus including a guide that is movable along said second side of the panels, an indexing foot coupled to said guide, a drilling device slidably coupled to said guide, a riveting device slidably coupled to said guide; applying said clamping force for sandwiching the panels in said predetermined configuration between said indexing foot and said clamping foot; drilling a hole in the panels; inserting a blank rivet in said hole; decreasing said clamping force by a predetermined amount; increasing said bucking force by about said predetermined amount; applying a substantially constant total force that is applied to the panels, said substantially constant total force being comprised of said clamping force and said bucking force.

40. actuating said riveting device for installing a rivet in the panels within said hole; unclamping the panels; positioning said integral clamping-and-bucking apparatus in a second predetermined position on a first side of the joint between the panels; positioning an integral drilling-and-riveting apparatus in said second predetermined position on a second side of the joint between the panels.

Description:

TECHNICAL FIELD

The present invention relates generally to riveted structures, and more particularly to an integral clamping-and-bucking apparatus for a system, which utilizes a substantially constant force for installing rivet fasteners in a joint.

BACKGROUND OF THE INVENTION

Aircrafts having riveted structures are well known. Examples of these riveted structures typically include an airframe, an instrument panel, and various other components of the aircraft. These riveted structures typically have sufficient strength for not failing under substantially high static loads and/or substantially high cyclical loads.

Manufacturers typically produce riveted structures in about four general steps. First, the components typically are aligned in a predetermined configuration and clamped with a joint therebetween. Then, a drilling device typically is moved to a predetermined position on the joint for drilling a hole in the components. Thereafter, the drilling device is removed from the components, and the components are separated for deburring, cleaning, and otherwise preparing the hole for receiving a blank rivet. The components typically are then re-assembled with the joint therebetween, and a riveting device is moved to the predetermined position on the joint for forming the rivet in the hole.

One skilled in the art will understand that maintaining proper alignment of the components during the drilling operation and the riveting operation can provide substantially strong riveted joints for not failing under high static loads and/or high cyclical loads.

It would therefore be desirable to provide an integral clamping-and-bucking apparatus for applying rivet fasteners to a joint so as to further improve the robust construction of riveted structures and decrease the manufacturing cycle time of those structures, as well as the costs associated therewith.

SUMMARY OF THE INVENTION

One embodiment of the present invention is an integral clamping-and-bucking apparatus for a system, which is utilized for applying rivet fasteners to two or more panels of sheet metal and forming a joint therebetween. The integral clamping-and-bucking apparatus includes a clamping foot for securing the panels in a predetermined configuration for precisely drilling a hole in the panels and riveting the panels at the joint. Also, the integral clamping-and-bucking apparatus further includes a bucking bar for bucking a blank rivet tail that extends from the hole. The clamping foot and the bucking bar are coupled to and actuated by a controller. This controller actuates the bucking bar and the clamping foot for transferring power between the clamping foot and the bucking bar while maintaining a substantially constant total force that is applied to the panels.

One advantage of the invention is that an integral clamping-and-bucking apparatus is provided that minimizes the deflection of the components of the riveted structure during the drilling operation and the riveting operation.

Another advantage of the present invention is that an integral clamping-and-bucking apparatus is provided that minimizes the internal stresses within a riveted structure so as to strengthen the riveted structure for supporting substantially high static loads and/or substantially high cyclical loads.

Yet another advantage of the present invention is that an integral clamping-and-bucking apparatus is provided that utilizes substantially high clamping forces for minimizing interfacial burrs that are produced in the components during the drilling operation and eliminating the need to disassemble the components to remove those burrs.

Still another advantage of the present invention is that an integral clamping-and-bucking apparatus is provided that enhances the rivet shank interference pattern so as to increase the fatigue resistance and the durability of the riveted structure.

Yet another advantage of the present invention is that an integral clamping-and-bucking apparatus is provided that decreases the manufacturing cycle time and the costs associated therewith.

The features, functions, and advantages can be achieved independently and in various embodiments of the present invention or may be combined in yet other embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of this invention, reference should now be made to the embodiments illustrated in greater detail in the accompanying drawings and described below by way of examples of the invention:

FIG. 1 is an exploded schematic view of a system having an integral clamping-and-bucking apparatus that is movable between a clamping position and a bucking position for applying rivet fasteners to a sheet metal joint, according to one advantageous embodiment of the claimed invention;

FIG. 2A is a plan view of the integral clamping-and-bucking apparatus shown in FIG. 1, illustrating the integral clamping-and-bucking apparatus moved to the clamping position;

FIG. 2B is a plan view of the integral clamping-and-bucking apparatus shown in FIG. 2A, illustrating the integral clamping-and-bucking apparatus moved to the bucking position;

FIG. 3A is an enlarged view of the integral clamping-and-bucking apparatus shown in FIG. 2A, as taken from circle 3A;

FIG. 3B is an enlarged plan view of the integral clamping-and-bucking apparatus shown in FIG. 2B, as taken from circle 3B;

FIG. 4 is an enlarged cross-sectional view of the system shown in FIG. 1, illustrating the integral clamping-and-bucking apparatus moved to the clamping position and utilizing a clamping foot for positioning the panels in a predetermined configuration;

FIG. 5 is an enlarged cross-sectional view of the system shown in FIG. 4, illustrating the integral clamping-and-bucking apparatus moved to the clamping position and utilizing the clamping foot for maintaining the panels in the predetermined configuration while a drilling device forms a hole within the panels at the joint;

FIGS. 6-8 are enlarged cross-sectional views of the system shown in FIG. 5, sequentially illustrating the integral clamping-and-bucking apparatus decreasing the force applied by the clamping foot and increasing the force applied by a bucking bar for forming a rivet tail while maintaining a substantially constant total force applied to the panels; and

FIG. 9 is a logic flow diagram of a method for utilizing the system shown in FIG. 1 for applying rivet fasteners to a sheet metal joint.

DETAILED DESCRIPTION OF THE INVENTION

In the following figures, the same reference numerals are used to identify the same or similar components in the various representative views.

The present invention is particularly suited for a system and method for utilizing an integral clamping-and-bucking apparatus for installing rivet fasteners in sheet metal joints of an aluminum aircraft skin. In this regard, the illustrated embodiments described herein employ features where the context permits, e.g. when a specific result or advantage of the claimed invention is desired. However, it is contemplated that the integral clamping-and-bucking apparatus can instead be utilized for various other manufacturing processes and/or for producing other airframe structures or various other suitable constructions as desired. For that reason, a variety of other embodiments are contemplated having different combinations of the described features, having features other than those described herein, or even lacking one or more of those features. It is therefore understood that the invention can be carried out in other suitable modes besides those described herein.

Referring to FIG. 1, there is shown an exploded schematic view of a system 10 having an integral clamping-and-bucking apparatus 12 (“CB apparatus”) for manufacturing an outer skin of an aircraft, according to one advantageous embodiment of the claimed invention.

The system 10 generally includes two or more panels 14a, 14b of sheet metal, an airframe structure 16 with the panels 14a, 14b attached thereto, the CB apparatus 12 disposed adjacent to an inboard side 18 of the panels 14a, 14b, and an integral drilling-and-riveting apparatus 20 (“DR apparatus”) disposed adjacent to an outboard side 22 of the panels 14a, 14b. In other words, the panels 14a, 14b are fastened to the airframe structure 16 and positioned in a predetermined configuration with one or more lap joints 24 therebetween.

The CB apparatus 12 and the DR apparatus 20 are utilized in combination for continuously clamping the panels 14a, 14b in the predetermined configuration with a substantially constant total force. This feature is beneficial for efficiently drilling and riveting a robust joint 24 therebetween. As detailed in the description for FIGS. 2A-9, the system 10 transfers power from a clamping foot 46 to a bucking bar 48 of the CB apparatus 12 for applying the substantially constant total force.

In this embodiment, the CB apparatus 12 and the DR apparatus 20 are integrated within a computer-numerically-controlled system (CNC system) for moving the CB apparatus 12 and the DR apparatus 20 along an x-axis, a y-axis, and a z-axis so as to install rivets 56 in predetermined positions on the joint 24. It is understood that this CNC system 10 is beneficial for providing the consistent, substantially precise manufacture of airframes within a short manufacturing cycle time.

Specifically, as shown in FIG. 1, the CB apparatus 12 is slidably mounted to a plate member 26 and one or more motors 12′ for moving the CB apparatus 12 substantially along the z-axis toward and away from the panels 14a, 14b. Also, the plate member 26 is slidably coupled to a carrier member 28 and a respective motor 26′ for moving the CB apparatus 12 substantially along the y-axis. Moreover, this carrier member 28 is slidably coupled to a pair of rail members 30 that extend from the airframe structure 16 and a respective motor 28′ for moving the CB apparatus 12 substantially along the x-axis. In this way, the CB apparatus 12 can be moved in various directions for drilling and riveting various portions of the panels 14a, 14b. Furthermore, the CB apparatus 12, the plate member 26, and the carrier member 28 each have a respective position encoder and laser sensor 12″, 26″, 28″ mounted thereon for detecting the position of the CB apparatus 12.

Each motor 12′, 26′, 28′ and the respective position encoders 12″, 26″, 28″ are coupled to a controller 32 for moving the CB apparatus 12 to the predetermined positions on the joint 24, which require a rivet fastener 56. In this way, as described above, the controller 32 can position the CB apparatus 12 for drilling and riveting the joint 24 with substantially high precision and at a substantially high speed.

Moreover, in this embodiment, the motor 12′ is a pneumatically-driven mechanism, e.g. a pressurized air cylinder, while the other motors 26′, 28′ are electrically-driven servo motors. However, it is contemplated that a screw mechanism, a pulley mechanism, various other suitable drive mechanisms, or any suitable combination thereof can be utilized as desired.

Additionally, each slidable coupling is a ball-bearing slidable coupling (not shown) between the respectable movable components 12, 26, 28, 30. However, it will be appreciated that a pivotal coupling, a rotatable coupling, various other suitable slidable couplings, or any combination thereof can be utilized as desired.

Furthermore, the DR apparatus 20 is slidably coupled to a tray member 34 and one or more motors 20′ for moving the DR apparatus 20 substantially along the z-axis toward and away from the outboard side 22 of the panels 14a, 14b. As detailed in the description for FIGS. 5-8, the DR apparatus 20 includes a drilling device 36 and a riveting device 38, which are both slidably coupled to the tray member 34 and respective motors 36′, 38′.

Additionally, the tray member 34 is slidably coupled to a guide member 40 and a respective motor 34′ for moving the DR apparatus 42 along a y-axis. Also, this guide member 40 is slidably coupled to a pair of rails 42, which are sealingly coupled to the outboard side 22 of the panels 14a, 14b, and a respective motor 40′ for moving the DR apparatus 20 substantially along the x-axis. Moreover, the DR apparatus 20, the tray member 34, and the guide member 40 each have a respective position encoder and laser sensor 20″, 34″, 40″ mounted thereon for detecting the position of the DR apparatus 20.

Each motor 20′, 34′, 40′ and the respective position encoder 20″, 34″, 40″ are coupled to the controller 32 for moving the DR apparatus 20 to the predetermined positions. In this way, as described above, the controller 32 can position the DR apparatus 20 for drilling and riveting the joint 24 with substantially high precision and at a substantially high speed.

Also, in this embodiment, the motor 20′ is a pneumatically-driven mechanism, e.g. a pressurized air cylinder, while the other motors, 34′, 40′ are electrically-driven servo motors. However, it is contemplated that a screw mechanism, a pulley mechanism, various other suitable drive mechanisms, or any suitable combination thereof can be utilized as desired.

In addition, each slidable coupling is a ball-bearing slidable coupling (not shown) between the respectable movable components 20, 34, 40, 42. However, it will be appreciated that a pivotal coupling, a rotatable coupling, various other suitable slidable couplings or any combination thereof can be utilized as desired.

In view of the above, it is understood that the CB apparatus 12 and the DR apparatus 20 can be secured to various suitable computer-numerically-controlled machines for moving the CB apparatus 12 and the DR apparatus 20 with substantially high accuracy and at a substantially high rate for manufacturing the aircraft skin or other suitable riveted structure.

Referring now to FIGS. 2A and 2B, there are illustrated plan views of the CB apparatus 12, as shown in FIG. 1, illustrating the CB apparatus 12 for continuously clamping the panels 14a, 14b in the predetermined configuration with a substantially constant total force. Specifically, FIG. 2A shows the CB apparatus 12 moved to a clamping position while FIG. 2B shows the CB apparatus 12 moved to a bucking position for bucking a rivet tail 62 in a hole 54 formed in those panels 14a, 14b.

The integral construction of the CB apparatus 12 generally includes a base member 50 with an end portion 44, a clamping foot 46 extending from the end portion 44, and a bucking bar 48 slidably coupled to the base member 50. As detailed in the descriptions for FIGS. 4-8, the clamping foot 46 and the bucking bar 48 respectively apply a clamping force and a bucking force to the panels 14a, 14b for securing the panels 14a, 14b in the predetermined configuration. The clamping force and the bucking force comprise a total force, which the controller 32 maintains at a substantially constant value. In this embodiment, the clamping force comprises 100% of the force that is applied to the panels 14a, 14b during the drilling process. Also, during the riveting operation, the controller 32 progressively transfers power from the clamping foot 36 to the bucking bar 48 so as to decrease the clamping force and increase the bucking force while maintaining a substantially constant total force applied to the panels 14a, 14b. It is also contemplated that power can be transferred between the clamping foot 36 and the bucking bar 48 at various rates and by various amounts, initial or otherwise, as desired.

Specifically, the base member 50 is slidably coupled to the plate member 26 substantially along the y-axis and the z-axis. In this way, the base member 50 is movable to the clamping position (best shown in FIG. 4) for forcing the clamping foot 46 onto the panels 14a, 14b against an indexing foot 52 (shown in FIG. 1), which extends from the DR apparatus 20. In this embodiment, the indexing foot 52 is first moved to a predetermined location, and the clamping foot 46 is then actuated to force the panels 14a, 14b against the indexing foot 52. However, it is contemplated that the panels 14a, 14b can be secured in the predetermined configuration via other suitable methods as desired.

With attention to FIGS. 5-8, as introduced hereinabove, the indexing foot 52 is utilized as a point of reference for positioning the panels 14a, 14b in a predetermined configuration and also as an opposing clamping structure to the clamping foot 46 for securing the panels 14a, 14b in the predetermined configuration. For that reason, the controller 32 utilizes the computer-numerically-controlled machines for extending the indexing foot 52 from the DR apparatus 20 to the predetermined location so as to precisely sandwich the panels 14a, 14b between the clamping foot 46 and the indexing foot 52 in the predetermined configuration during the drilling operation and the riveting operation.

As best shown in FIGS. 3A and 3B, the clamping foot 46 has a ring construction for applying a substantially evenly distributed clamping force to the inboard side 18 of the panels 14a, 14b. In addition, the indexing foot 52 also has a ring construction for applying a substantially evenly distributed opposing force to the outboard side 22 of the panels 14a, 14b. The indexing foot 52 has a ring construction that is similarly shaped and sized for substantially aligning with the clamping foot 46. This feature is beneficial for minimizing the risk of skin deflection during the drilling operation and the riveting operation.

Referring back to FIG. 4, the controller 32 concentrically aligns the respective ring constructions of the clamping foot 46 and the indexing foot 52 on the inboard side 18 and the outboard side 22 of the panels 14a, 14b. In this way, one skilled in the art will appreciate that the indexing foot 52 and the clamping foot 46 provide substantially distributed support for securing the panels 14a, 14b in the predetermined configuration. For that reason, the indexing foot 52 and the clamping foot 46 minimize the deflection of the panels 14a, 14b during the drilling operation (shown in FIG. 5) and the riveting operation (sequentially shown in FIGS. 6-8). This feature is beneficial for utilizing a substantially high clamping force for efficiently minimizing interfacial burrs that are produced in the panels 14a, 14b during the drilling operation and also eliminating the need to disassemble the panels 14a, 14b to remove those burrs.

Specifically, referring now to FIGS. 1 and 5, the controller 32 actuates the motor 32′ coupled to the tray member 34 for moving the drilling device 36 along the y-axis and positioning the drilling device 36 at the predetermined position for drilling a hole 54 in the clamped panels 14a, 14b. The controller 32 then actuates the drilling device 36 and a motor 36′ coupled to the drilling device 36 for moving the drilling device 36 along the z-axis and forming the hole 54 in the panels 14a, 14b.

As described hereinabove, the drilling device 36 preferably is positioned for forming the hole 54 in a portion of the joint 24 that is substantially concentrically clamped between the indexing foot 52 and the clamping foot 46. In that way, the panels 14a, 14b are substantially supported by the indexing foot 52 and the clamping foot 46 for minimizing the deflection of the panels 14a, 14b by the drilling device 36 during the drilling operation.

Referring now to FIGS. 1 and 6-8, after the drilling operation, the clamping foot 46 initially continues to apply substantially all of the force to the panels 14a, 14b. During the riveting operation, the controller progressively transfers power from the clamping foot 46 to the bucking bar 48 while maintaining a substantially constant total force. At the commencement of the riveting operation, the controller 32 progressively decreases the clamping force and increases the bucking force so as to maintain a substantially constant total force. In this embodiment, the bucking force is equal to or greater than a minimum threshold at the beginning of the riveting operation and progressively increases thereafter. In that way, the bucking bar 48 is utilized for securing a blank rivet 56 in a seated position within the hole 54 as the riveting device 38 begins applying impulse forces to the rivet 56.

Specifically, during the riveting operation, the blank rivet 56 is inserted into the hole 54 either manually by an operator or automatically with a computer-controlled mechanism (not shown). Immediately thereafter, the controller 32 actuates the motor 34′ for moving the tray member 34 along the y-axis so as to accurately position the riveting device 38 at the predetermined position. The controller 32 then actuates the riveting device 38 and a motor 40′ coupled to the riveting device 38 for moving the riveting device 38 along the z-axis and installing a rivet 56 within the hole 54.

Also in this embodiment, the indexing foot 52 has a rigid construction for normalizing the panels 14a, 14b in the predetermined configuration. In addition, the clamping foot 46 is comprised of an elastic deformable material, e.g. polyurethane, for deforming against the panels 14a, 14b as the clamping foot 46 forces the panels 14a, 14b against the indexing foot 52 in the predetermined configuration. It will be appreciated that this feature is beneficial for evenly distributing a clamping force substantially across the portion of the joint 24 that is drilled and riveted. Moreover, this feature locates the panels 14a, 14b in the predetermined configuration without having to precisely align the clamping foot 46 with the indexing foot 52 within substantially small tolerances. It is understood that this feature simplifies the clamping process.

It is contemplated that the clamping foot 46 and/or the indexing foot 52 can have various other suitable constructions and be comprised of other suitable materials for precisely clamping the panels 14a, 14b in the predetermined configuration, minimizing the deflection of the panels 14a, 14b, and applying a substantially distributed clamping force to those panels 14a, 14b.

The bucking bar 48 is slidably coupled to the base member 50 and the respective motor 48′ for moving the bucking bar 48 substantially along the z-axis to the bucking position (best shown in FIGS. 2B, 3B, and 8). Specifically during the riveting operation, as best shown in FIGS. 6-8, the controller 32 actuates the bucking bar 48 to extend through a channel 58 formed in the end portion 44 of the base member 50 and contact the unformed tail 62 of the rivet 56.

Also in this embodiment, the bucking bar 48 includes a weight portion 60 of a predetermined mass for assisting the bucking bar 48 in applying a bucking force to the blank rivet tail 62 while the controller 32 actuates the riveting device 38 to apply a multiple impact force on an opposing end of the rivet 56. It is contemplated that the bucking bar 48 can have various other suitable constructions as desired.

In accordance with the invention, as sequentially illustrated in FIGS. 6-8, the controller 32 continuously actuates the CB apparatus 12 for applying a substantially constant total force to the panels 14a, 14b. Specifically, as detailed above, the total force is the sum of the clamping force applied by the clamping foot 46 and the bucking force applied by the formed rivet tail 62 and the bucking bar 48. In this regard, during the riveting operation, the controller progressively actuates the CB apparatus 12 to decrease the clamping force and increase the bucking force. In that way, the rivet 56 is installed in the joint 24 while the system 10 maintains a substantially constant total force on the panels 14a, 14b.

As a result, the system 10 enhances the rivet shank interference pattern, improves the head-and-shank interference, and substantially strengthens the joint 24. However, it is contemplated that the controller 32 can instead regulate the clamping force and the bucking force according to a variety of other suitable methods.

Referring now to FIG. 9, there is shown a logic flow diagram of a method for utilizing the system 10, illustrated in FIG. 1, to manufacture an aluminum skin of an aircraft. The sequence commences in step 100 and then immediately proceeds to step 102.

In step 102, two or more panels 14a, 14b of sheet metal are fastened to the airframe structure 16 and positioned in the predetermined configuration with one or more lap joints 24 therebetween. Also in this embodiment, the CB apparatus 12 and the DR apparatus are mounted to the panels 14a, 14b via the respective rails 30, 42. Then, the sequence proceeds to step 104.

In step 104, the CB apparatus 12 and the DR apparatus 20 are located in a first predetermined position respectively on the inboard side 18 and the outboard side 22 of the panels 14a, 14b. This step is accomplished by actuating the computer-numerically-controlled machine detailed hereinabove. However, it is contemplated that a variety of other suitable positioning mechanisms and methods can be utilized as desired. The sequence then proceeds to step 106.

In step 106, the panels 14a, 14b are clamped in the predetermined configuration. Specifically, in this embodiment, the controller 32 utilizes the computer-numerically-controlled machine for positioning the indexing foot 52 in the predetermined position on the joint 24 and actuating the clamping foot 46 to force the panels 14a, 14b against the indexing foot 52 in the predetermined configuration. The mechanisms utilized for accomplishing this step are exemplified in the description for FIGS. 1-8. Thereafter, the sequence proceeds to step 108.

In step 108, the drilling device 36 moves to the predetermined position and forms the hole 54 within the panels 14a, 14b while the indexing foot 52 and the clamping foot 46 secure the panels 14a, 14b in the predetermined configuration. The mechanisms utilized for accomplishing this step are exemplified above. The sequence then proceeds to step 110.

In step 110, the riveting device 38 moves to the predetermined position on the joint and installs the rivet 56 in the hole 54 of the joint 24. Specifically, as described hereinabove and sequentially illustrated in FIGS. 6-8, the controller 32 transfers power from the clamping foot 46 to the bucking bar 48 so as to decrease the clamping force and increase the bucking force while maintaining a substantially constant total force on the panels 14a, 14b. Then, the sequence proceeds to step 112.

In step 112, the DR apparatus 20 and the CB apparatus 12 are unclamped from the panels 14a, 14b. The sequence then immediately proceeds to step 114.

In step 114, the DR apparatus 20 and the CB apparatus 12 are moved to a second predetermined position respectively on the outboard side 22 and the inboard side 18 of the panels 14a, 14b. Immediately thereafter, the sequence returns to step 106.

While particular embodiments of the invention have been shown and described, numerous variations and alternate embodiments will occur to those skilled in the art. Accordingly, it is intended that the invention be limited only in terms of the appended claims.