U.S. patent application number 10/904978 was filed with the patent office on 2006-06-08 for integral clamping-and-bucking apparatus for utilizing a constant force and installing rivet fasteners in a sheet metal joint.
This patent application is currently assigned to THE BOEING COMPANY. Invention is credited to Donald W. Coffland, Paul E. Ffield.
Application Number | 20060117547 10/904978 |
Document ID | / |
Family ID | 36572536 |
Filed Date | 2006-06-08 |
United States Patent
Application |
20060117547 |
Kind Code |
A1 |
Ffield; Paul E. ; et
al. |
June 8, 2006 |
INTEGRAL CLAMPING-AND-BUCKING APPARATUS FOR UTILIZING A CONSTANT
FORCE AND INSTALLING RIVET FASTENERS IN A SHEET METAL JOINT
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) ; Coffland; Donald W.; (Seattle,
WA) |
Correspondence
Address: |
OSTRAGER CHONG FLAHERTY & BROITMAN PC
250 PARK AVENUE, SUITE 825
NEW YORK
NY
10177
US
|
Assignee: |
THE BOEING COMPANY
100 North Riverside
Chicago
IL
|
Family ID: |
36572536 |
Appl. No.: |
10/904978 |
Filed: |
December 8, 2004 |
Current U.S.
Class: |
29/525.06 ;
29/243.53; 29/796 |
Current CPC
Class: |
Y10T 29/53422 20150115;
Y10T 29/49956 20150115; B21J 15/28 20130101; B21J 15/02 20130101;
B21J 15/14 20130101; Y10T 29/5377 20150115; B21J 15/142
20130101 |
Class at
Publication: |
029/525.06 ;
029/243.53; 029/796 |
International
Class: |
B21J 15/02 20060101
B21J015/02 |
Claims
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
[0001] 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
[0002] 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.
[0003] 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.
[0004] 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.
[0005] 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
[0006] 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.
[0007] 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.
[0008] 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.
[0009] 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.
[0010] 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.
[0011] 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.
[0012] 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
[0013] 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:
[0014] 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;
[0015] 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;
[0016] 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;
[0017] FIG. 3A is an enlarged view of the integral
clamping-and-bucking apparatus shown in FIG. 2A, as taken from
circle 3A;
[0018] FIG. 3B is an enlarged plan view of the integral
clamping-and-bucking apparatus shown in FIG. 2B, as taken from
circle 3B;
[0019] 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;
[0020] 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;
[0021] 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
[0022] 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
[0023] In the following figures, the same reference numerals are
used to identify the same or similar components in the various
representative views.
[0024] 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.
[0025] 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.
[0026] 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.
[0027] 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.
[0028] 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.
[0029] 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.
[0030] 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.
[0031] 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.
[0032] 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.
[0033] 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'.
[0034] 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.
[0035] 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.
[0036] 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.
[0037] 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.
[0038] 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.
[0039] 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.
[0040] 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.
[0041] 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.
[0042] 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.
[0043] 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.
[0044] 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.
[0045] 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.
[0046] 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.
[0047] 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.
[0048] 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.
[0049] 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.
[0050] 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.
[0051] 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.
[0052] 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.
[0053] 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.
[0054] 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.
[0055] 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.
[0056] 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.
[0057] 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.
[0058] 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.
[0059] 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.
[0060] 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.
[0061] 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.
[0062] 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.
[0063] 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.
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