U.S. patent application number 09/956565 was filed with the patent office on 2002-01-31 for reduced weight aircraft collar and method of making same.
Invention is credited to Avetisian, Edward, Diamond, Todd, Duran, John A..
Application Number | 20020012578 09/956565 |
Document ID | / |
Family ID | 24205487 |
Filed Date | 2002-01-31 |
United States Patent
Application |
20020012578 |
Kind Code |
A1 |
Duran, John A. ; et
al. |
January 31, 2002 |
Reduced weight aircraft collar and method of making same
Abstract
A nut or collar formed from a high-speed cold working process
wherein the nut or collar has portions of the material forming the
nut or collar removed therefrom thereby maintaining the strength of
the nut or collar. The removed material is preferably in the form
of curved scallops at the base of the collar or nut at spaced
locations thereon formed during the cold working process.
Inventors: |
Duran, John A.; (Glendora,
CA) ; Avetisian, Edward; (Burbank, CA) ;
Diamond, Todd; (Santa Paula, CA) |
Correspondence
Address: |
Oppenheimer Wolff & Donnelly LLP
Suite 3800
2029 Century Park East
Los Angeles
CA
90067
US
|
Family ID: |
24205487 |
Appl. No.: |
09/956565 |
Filed: |
September 18, 2001 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
09956565 |
Sep 18, 2001 |
|
|
|
09552474 |
Apr 18, 2000 |
|
|
|
6290445 |
|
|
|
|
Current U.S.
Class: |
411/427 |
Current CPC
Class: |
F16B 39/30 20130101;
F16B 5/0208 20130101 |
Class at
Publication: |
411/427 |
International
Class: |
F16B 037/00 |
Claims
We claim:
1. A reduced weight aircraft collar comprising: a base portion
having an outer periphery and a terminal end; a forward shank
portion; an intermediate portion interconnecting said base portion
and said shank portion; a throughbore extending through said
collar; and a plurality of spaced cut-out portions extending about
the outer periphery of said base portion.
2. The collar of claim 1 wherein a portion of said throughbore is
threaded.
3. The collar of claim 1 wherein said cut-out portions are
scalloped portions, each of said scalloped portions having an
arched portion adjacent the terminal end of said base portion, with
spaced side portions extending from opposite sides of said arched
portions to the junction of said base portion with said
intermediate portion.
4. The collar of claim 1 wherein said collar is of metal formed
from a high-speed cold-worked process.
5. The collar of claim 4 wherein said collar is of stainless
steel.
6. The collar of claim 3 wherein six scalloped portions are
provided.
7. The collar of claim 1 wherein said intermediate portion has an
outer diameter less than the outer diameter of said shank
portion.
8. The collar of claim 1 wherein said base portion has a first
generally cylindrical portion tapering to an enlarged circular
portion at said terminal end.
9. The collar of claim 1 wherein said intermediate portion is
generally cylindrical and lesser in outer diameter than said base
portion.
10. The collar of claim 1 wherein a breakaway groove separates said
shank portion from said intermediate portion.
11. The collar of claim 10 wherein said shank portion is hex-shaped
in outer configuration.
12. The collar of claim 10 wherein said shank portion is smooth
walled in outer configuration.
13. A reduced weight aircraft collar comprising: a base portion
having an outer periphery and a terminal end; a shank portion
integral with said base portion; a throughbore extending through
said portions; and a plurality of spaced cut-out portions extending
about the outer periphery of said base portion.
14. The collar of claim 13 wherein said at least one of said
portions of said throughbore is threaded.
15. The collar of claim 13 wherein said shank portion is hex-shaped
in outer configuration.
16. The collar of claim 13 wherein said shank portion is
smooth-walled in outer configuration.
17. The collar of claim 16 wherein at least one of said portions of
said throughbore is threaded.
18. The collar of claim 13 wherein said cut-out portions are
scalloped portions, each of said scalloped portions having an
arched portion adjacent the terminal end of said base portion, with
spaced side portions extending from opposite sides of said arched
portions to the junction of said base portion with said
intermediate portion.
19. A method of forming a reduced weight collar having a base
portion having an outer periphery and a terminal end, a forward
shank portion, an intermediate portion interconnecting said base
portion and said shank portion, and a throughbore extending through
at least one of said portions, the method comprising the steps of:
forming a plurality of spaced cut-out portions extending about the
outer periphery of said base portion.
20. The method of claim 19 wherein the step of forming said spaced
cut-out portions includes the step of forming scalloped portions,
each having an arched portion adjacent the terminal end of said
base portion, with spaced side portions extending from opposite
sides of said arched portions to the junction of said base portion
with said intermediate portion.
21. The method of claim 19 wherein the step of forming said
portions includes the step of forming the same during a high-speed
cold-working process.
22. A reduced weight aircraft collar comprising: a base portion
having an outer periphery and a terminal end; a forward shank
portion integral with said base portion; a throughbore extending
through at least one of said portions; and a plurality of spaced
cut-out portions extending about the outer periphery of said base
portion.
23. The collar of claim 22 wherein said throughbore is
threaded.
24. The collar of claim 22 wherein said cut-out portions are
scalloped portions, each of said scalloped portions having an
arched portion adjacent the terminal end of said base portion, with
spaced side portions extending from opposite sides of said arched
portions to the junction of said base portion with said shank
portion.
25. The collar of claim 24 wherein said collar is of metal formed
from a high-speed cold-working process.
26. The collar of claim 25 wherein said collar is of stainless
steel.
27. The collar of claim 24 wherein six scalloped portions are
provided.
28. The collar of claim 22 wherein said base portion has a first
generally tapered portion tapering to an enlarged circular portion
at said terminal end.
29. The collar of claim 22 wherein said shank portion is hex-shaped
in outer configuration.
30. The collar of claim 22 wherein said shank portion is smooth
walled in outer configuration.
31. A method of forming a reduced weight collar from a round wire
comprising the steps of: cold-working said wire in a high-speed
process to form the same into a collar having a base portion with
an outer periphery and a terminal end, a forward shank portion, and
an intermediate portion interconnecting the base portion and the
shank portion with a throughbore through at least one of said
portions, and a plurality of spaced cut-out portions extending
about the outer periphery of said base portion, the flow of grain
of the material of said collar being along lines generally parallel
to the longitudinal axis of said collar, but flowing outwardly and
curving about said scalloped portions at the terminal end of said
base portion.
32. A method of forming a reduced weight collar from a round wire
comprising the steps of: cold-working said wire in a high-speed
process to draw the same into a collar having a base portion with
an outer periphery and a terminal end, an integral forward shank
portion with a throughbore through at least one of said portions,
and a plurality of spaced cut-out portions extending about the
outer periphery of said base portion, the flow of grain of the
material of said collar being along lines generally parallel to the
longitudinal axis of said collar, but flowing outwardly and curving
about said scalloped portions at the terminal end of said base
portion.
33. A method of installing a nut or collar into an installation and
removing the same therefrom comprising the steps of cold working a
round wire to form a nut or collar. cold-working said wire in a
high-speed process to draw the same into a collar having a base
portion with an outer periphery and a terminal end, an integral
forward shank portion with a throughbore through at least one of
said portions, and a plurality of spaced cut-out portions extending
about the outer periphery of said base portion, the flow of grain
of the material of said collar being along lines generally parallel
to the longitudinal axis of said collar, but flowing outwardly and
curving about said scalloped portions at the terminal end of said
base portion.
Description
CROSS-REFERENCE To RELATED APPLICATIONS
[0001] This application is a continuation-in-part of application
Ser. No. 09/552,474, filed Apr. 18, 2000.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to aircraft fasteners, and
particularly to nuts or collars that threadably mate to pins and
the method of making the same.
[0004] 2. Related Art
[0005] In our U.S. patent application Ser. No. 09/552,474, filed
Apr. 18, 2000, and commonly assigned, we disclose a fastener having
a pin with a specific thread and a plurality of nuts adapted to
threadably mate with the pin. One of these nuts is disclosed as
having a plurality of generally rectangular cut-out areas spaced
about the outside periphery of the nut. The nut has a threaded bore
adapted to mate with the modified thread of the pin.
[0006] The cut-out areas on the nut reduce the overall weight of
the nut. This reduction will amount to a great savings in overall
aircraft weight, since so many nuts are required on the aircraft.
As in our pending application Ser. No. 09/552,474, such savings in
weight must be accomplished without compromising aircraft industry
standards.
[0007] There is a need for a nut or collar having such weight
savings that can be threaded to any threaded pin. Many different
types of nuts or collars are used in the aircraft industry. Many of
these collars or nuts are designed for single-use applications and
are used to fasten aircraft panels to the aircraft structure. This
is shown in FIGS. 1 and 8 of our pending application Ser. No.
09/552,474 and described therein. However, existing nuts or collars
used in the aircraft industry do not incorporate means for removing
the nuts or collars from the installation if necessary. For
example, existing nuts or collars that incorporate a hex portion
for installation have such hex portion broken off or removed during
installation. This allows no way by which to remove the collar or
nut.
[0008] This need to reduce weight and yet still satisfy aircraft
industry standards is a key element in the design of any such nut
or collar. There is also a need for removing such a nut or collar
from the installation if necessary.
INVENTION SUMMARY
[0009] It is an object of this invention to provide a threaded nut
or collar for use in the aircraft industry that can be fastened to
any conventional pin or to the threaded pin in our co-pending
application Ser. No. 09/552,474, the teachings of which are
incorporated herein by reference, which has substantially reduced
weight, yet still satisfies aircraft industry standards.
[0010] It is a further object of this invention to provide a nut or
collar having portions of the material forming the nut or collar
removed therefrom, using a high-speed cold working process, thereby
maintaining the strength of the nut or collar.
[0011] It is still further an object of this invention to provide a
method of making such nuts or collars.
[0012] It is still another object of this invention to provide a
method of using such portions to install or such nuts or collars to
an installment or remove such nuts or collars from the
installation.
[0013] These and other objects are preferably accomplished by
forming curved scallops at the base of the collar or nut at spaced
locations during a cold-working process on the nut or collar.
Further weight saving may be made between the shank of the nut or
collar and the base of the nut or collar by reducing the diameter
of the nut or collar.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is perspective view of a collar in accordance with
the teachings of the invention;
[0015] FIG. 2 is a detailed view of one of the cut-out areas alone
of the collar of FIG. 1;
[0016] FIG. 3 is a cross-sectional view of the collar of FIGS. 1
and 2;
[0017] FIG. 4 is a view taken along lines 4-4 of FIG. 3;
[0018] FIG. 5 is a detailed view of the breakaway groove of the nut
or collar of FIGS. 1 to 4;
[0019] FIG. 6 is a perspective view of the nut or collar of FIG. 3
after breakoff of the hex shank portion of the nut or collar;
[0020] FIG. 7 is a view similar to FIG. 3 of a modified nut or
collar;
[0021] FIG. 8 is an elevational view of a modification of a nut or
collar in accordance with the teachings of the invention;
[0022] FIG. 9 is a cross-sectional view of the nut or collar of
FIG. 8;
[0023] FIG. 10 is a perspective view of a nut or collar similar to
the nut or collar of FIGS. 8 and 9 having a smooth bore
interior;
[0024] FIG. 11 is a perspective view of prior art hex shaped bar
stock;
[0025] FIG. 12 is a cross-sectional view of a nut or collar, such
as the nut or collar of FIG. 1, formed by a conventional
process;
[0026] FIG. 13 is a cross-sectional view of a nut or collar, such
as the nut or collar of FIG. 1, formed by high speed cold forming
process of the invention illustrating grain flow;
[0027] FIG. 14 is a cross-sectional view of the nut or collar of
FIG. 13 illustrating the final configuration; and
[0028] FIG. 15 is a view similar to FIG. 10 illustrating another
version of the nut or collar of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] Referring now to FIG. 1 of the application, an aircraft nut
or collar 10 is shown. Nut or collar 10 has a base portion 11, an
integral intermediate generally cylindrical portion 12, and a
forward shank portion 13 integral with cylindrical portion 12 and
separated therefrom by breakaway groove 14 (see FIGS. 3 and 5).
[0030] Nut or collar 10 includes a throughbore 15 which is
preferably threaded and adapted to threadably mate with the
threaded shank of an aircraft pin. This preferred thread may be
conventional, to thereby mate with the thread of a conventional
aircraft pin. Alternatively, the inner threaded bore 15 of nut or
collar 10 may have a thread adapted to mate with the thread of a
pin as described and claimed in our co-pending application Ser. No.
09/552,474, the teachings of which are incorporated by reference.
Further, the throughbore 15 may be smooth and interlock with the
annular ridges or threads of a pin.
[0031] As seen in FIGS. 1 and 3, the cylindrical portion 12 tapers
to base portion 11 which is greater in outer diameter than
intermediate portion 12.
[0032] A plurality of spaced scalloped portions 18, such as 6 such
portions (see FIG. 4), are provided cut-out of base portion 11 of
nut or collar 10, generally equally spaced therearound. One of the
scalloped portions 18 is shown in detail in FIG. 2. Each scalloped
portion 18 thus has an upper curved arch portion 19 that curves
downwardly on each side thereof (sides 20 and 21, respectively)
away from arch portion 19 to the bottom thereof (adjacent
mid-portion 12). It can be seen that the spacing between terminal
ends 22 and 23 of sides 20 and 21, respectively, is equal to the
spacing between sides 20 and 21 at their greatest width.
[0033] The nut or collar 10 is preferably of metal, such as
stainless steel, and is formed in any suitable manner. The
scalloped portions 18 are formed in the metallic material during a
high-speed cold forming process.
[0034] The carving out of the scalloped portions 18 removes weight
while retaining the structural integrity of the nut or collar using
the high-speed cold forming process. This method results in a nut
or collar 10 that is about 18% to 25% lighter in weight than
currently-used aircraft nuts or collars, while at the same time
meeting aircraft industry standards.
[0035] The scalloped portions 18 about the base portion 11 of the
nut or collar 10 are arranged to maximize the aforementioned weight
savings and minimize the impact of the structural integrity of the
nut or collar due to the weight reduction.
[0036] Further weight reduction may be made by reducing the outer
diameter of the section 12' (FIG. 7.--like numerals referring to
like parts of the nut or collar 10 of FIG. 3). Also, in this
embodiment, throughbore 15' may be smooth instead of threaded, as
shown.
[0037] The outer hex configuration of nut or collar 10 assists in
driving the same onto the mating thread of a pin, using a suitable
installation tool. By using a high-speed cold forming process, high
volume production of such nuts or collars is attained with improved
metallurgical characteristics imparted to the nuts or collars for
strength purposes.
[0038] The large curved surfaces and radiused corners of the
scalloped portions 18 reduce stress concentrations and provide an
efficient load path. This has been evidenced in testing of nuts or
collars 10 formed using the techniques disclosed herein.
[0039] As seen in FIG. 5, the breakaway groove 14 enables the
hex-shaped shank portion 13 to break off during installation of nut
or collar 10 (broken off at area 100 in FIG. 6). That is, as the
collar 10 is installed and bottoms out against the application, the
shank portion 13 breaks off at the correct torque. The torque value
relates to the tension preload of the collar and pin assembly.
[0040] Any suitable dimensions may be used. For a 1/4" fastener
diameter, the diameter of the breakoff groove 14 may be about
{fraction (5/16)} of an inch, and the sides surrounding the groove
14 may be at an angle a of about 30.degree. (see FIG. 5). For a
1/4" thread diameter of a fastener, each scalloped portion 18 may
be about 0.125 inches long, about 0.020 inches deep and about 0.125
inches at their widest part. As seen in FIG. 4, the spacing c
between portions 18a and 18c (separated by portion 18b) may be
about 0.340 inches. The angle between the centerline of adjacent
portions, such as portions 18d and 18e, may be about 60.degree.
(see angle d in FIG. 4).
[0041] As seen in FIG. 8, further weight reduction can be made by
eliminating intermediate portion 12 as seen in nut or collar 60 in
FIG. 8. Nut or collar 60 has a hex portion 61 and an integral base
portion 62 having a first tapered portion 63 leading from portion
61 to a cylindrical portion 64, greater in outer diameter than
portion 61. A plurality of scalloped portions 65, such as 6, are
spaced about the outer periphery of portion 64 identical to the
scalloped portions 18 of FIG. 1. These scalloped portions 65 can
also be used to drive nut or collar 60 by grasping the same
manually or using a suitable tool, such as pliers or any other tool
having a suitably configured nose piece, so as to grasp the nut or
collar 60 at the portions 65. Thus, such portions 65 or portion 61
can be used to install or remove nut or collar 60 from its
application. Such portions 65 can also be used in like manner to
grasp the nut or collar 60, using any suitable tool, to remove the
nut or collar 60.
[0042] As seen in FIG. 9, nut or collar 60 may be threaded on its
interior threads 66 adapted to mate with a threaded bolt as
heretofore discussed. Alternatively, as seen in FIG. 10, wherein
like numerals refer to like parts of FIG. 8, nut or collar 67 may
have a smooth or non-threaded throughbore 68 which mates and
interlocks with annular ridges or threads of a suitable bolt by
swaging of the collar 67 on to the threads or ridges of a bolt.
Thus, the nut or collar 67 is designed to be swaged onto the mating
pin or bolt. It may also be smooth walled, as at wall 72, on its
outer surface. The scalloped portions 65 are thus used to install
or remove the nut or collar in an installation if threaded to a
threaded pin or bolt.
[0043] The nut or collars disclosed in FIGS. 1 to 10 may be formed
in any suitable manner known in the prior art. For example, a hex
shaped bar 69 of stainless steel or aluminum is shown in FIG. 11.
Such bar may be about 0.437 inches in hex size. Normally, a nut or
collar formed from a conventional process, such as nut or collar 70
in FIG. 12, (essentially identical to the nut or collar 10 of FIG.
1), would have grain flow extending in grain flow lines parallel to
the longitudinal axis of nut or collar 70 as seen by line 71.
[0044] Using a conventional high-speed cold-worked process, round
wire of stainless, titanium, or aluminum may be used to form nuts
or collars, such as the nuts or collars disclosed in FIGS. 1 to 10,
one of which, nut or collar 72, is shown in FIG. 13. Prior to
forming groove 14, grain flow is along grain flow lines 73 parallel
to the longitudinal axis of nut or collar 72 at the shank portion
74, intermediate portion 75, and base portion 76 terminating in
enlarged terminal end 77. It is to be understood that the blank
shown in FIG. 13 is the first step in the process of forming the
final configuration of the nut or collar 78 shown in FIG. 14.
[0045] As can be seen in FIG. 13, the grain flow lines 79, at
terminal end 77, flow or curve from lines 73 as shown. The final
configuration of the nut or collar blank shown in FIG. 14 shows a
groove 80, similar to groove 14, has now been formed and
intermediate portion 75 may be threaded on its interior, at threads
81, (or left otherwise smoothbored, as previously discussed).
[0046] The grain flow formed on the nut or collar 78 of FIGS. 13
and 14 results in a stronger part, the material flowing into the
scalloped portions 82 as seen in FIGS. 13 and 14 (portions 82 being
otherwise identical to the scalloped portions, such as portion 18,
as otherwise discussed).
[0047] In addition to the weight-to-strength efficiency of nut or
collar 10 accomplished herein, a more effective sharing of the
weight between all of the threads of the threaded throughbore 15
takes place. The reduction in material provided by scalloped
portions 18 at the base portion 11 of nut or collar 10 allows
adequate deflection on the nut or collar 10 to induce a moment at
base portion 11. In turn, the moment induces a centrifugal
deflection of the base portion 11, which consequently relieves the
load concentration of the first few internal threads of nut or
collar 10 and redistributes the load more evenly among the rest of
the internal threads. The effect of the material removal geared for
weight reduction also promotes the equal sharing of the load by all
the threads of the threaded throughbore 15 of nut or collar 10.
[0048] Still another version of the nut or collar of the invention
is shown in FIG. 15 wherein like numerals refer to like parts of
the nut or collar of FIG. 10. Here, nut or collar 70 has a threaded
throughbore 72 and a smooth walled exterior 71. It may be threaded
to a threaded bolt, as heretofore discussed, and installed or
removed from an installation using scalloped portions 65, as
heretofore discussed.
[0049] The term "thread" as used herein includes a helical thread
having spaced thread portions, or a plurality of spaced annular
thread portions or ridges, each separate from the other and
separated by grooves. Any suitable dimensions may be used. The
threaded throughbore 15 of nut or collar 10 may be in conformance
with well-known standards in the aircraft industry for conventional
nuts or collars, or modified in accordance with industry standards,
as disclosed in our co-pending application Ser. No. 09/552,474.
[0050] The invention disclosed herein greatly reduces the weight of
the nut or collar without compromising the strength required for
the particular application in the aircraft industry. All of the
embodiments herein are formed by a high speed cold working
process.
[0051] It can be seen that various versions of a nut or collar can
be formed using the techniques of the invention all having pockets
or scallops or cut-out portions formed in the nut or collar during
a high speed cold working process. These versions are as
follows:
[0052] 1. A round collar or nut as shown in FIG. 1. The nut or
collar has internal threads and a twist off hex portion 13 and is
installed (or removed) using the twist-off hex portion 13.
[0053] 2. A hex nut or collar with a threaded portion as shown in
FIG. 8. This nut or collar may be installed (or removed) using
either the scalloped portions 65 or the hex portion 61.
[0054] 3. A round collar or nut with an internal threaded portion
as seen in FIG. 15. In this embodiment, the nut or collar is
installed (or removed from an installation) using scalloped
portions 65 as heretofore discussed.
[0055] 4. A round collar with a smooth throughbore as seen in FIG.
10. In this version, the nut or collar is swaged onto the threads,
serrations or annular ridges or grooves of a threaded bolt. The
scalloped portions 65 are used to install (or remove) this version
from its installation if installed on to a threaded pin or
bolt.
[0056] Thus, the nuts or collars disclosed herein allow the nut or
collar to be installed using the scalloped portions or removed from
the installation using the scalloped portions. The scalloped
portions provide weight reduction while at the same time allow the
customer the additional option of using such scalloped portions to
install the nuts or collars or, if necessary, remove the nuts or
collars from the installation.
[0057] Although a particular embodiment of the invention is
disclosed, variations thereof may occur to an artisan, and the
scope of the invention should only be limited by the scope of the
appended claims.
* * * * *