U.S. patent application number 09/757783 was filed with the patent office on 2001-05-17 for fastener die member, panel and fastener assembly and method of installing a fastener.
Invention is credited to Ladouceur, Harold A., Woods, Harold T..
Application Number | 20010001166 09/757783 |
Document ID | / |
Family ID | 32096417 |
Filed Date | 2001-05-17 |
United States Patent
Application |
20010001166 |
Kind Code |
A1 |
Ladouceur, Harold A. ; et
al. |
May 17, 2001 |
Fastener die member, panel and fastener assembly and method of
installing a fastener
Abstract
The present invention relates to an improved die member, panel
and fastener assembly and method for installing a fastener into a
panel. The die member has a pair of opposed clinching lips
protruding from an end face. The opposed clinching lips have a
contact face that narrows as it approaches the opposed ends of the
contact face and sidewalls that are angled with respect to
vertical. The lips, due to the dual angles, substantially and
simultaneously drive panel metal into fastener grooves both
longitudinally and laterally. The fastener and panel assembly have
panel metal deformed into the fastener grooves resulting in
generally wedge-shaped portions of panel metal in the opposed ends
of the fastener grooves.
Inventors: |
Ladouceur, Harold A.;
(Livonia, MI) ; Woods, Harold T.; (Canton,
MI) |
Correspondence
Address: |
William H. Honaker
Howard & Howard Attorneys, P.C.
The Pinehurst Office Center, Suite #101
39400 Woodward Avenue
Bloomfield Hills
MI
48304-5151
US
|
Family ID: |
32096417 |
Appl. No.: |
09/757783 |
Filed: |
January 10, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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09757783 |
Jan 10, 2001 |
|
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09302215 |
Apr 29, 1999 |
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60083578 |
Apr 30, 1998 |
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Current U.S.
Class: |
29/505 ;
29/522.1 |
Current CPC
Class: |
Y10T 29/49938 20150115;
F16B 37/068 20130101; Y10T 29/49908 20150115; B23P 19/062 20130101;
Y10T 29/53709 20150115 |
Class at
Publication: |
29/505 ;
29/522.1 |
International
Class: |
B21D 039/00 |
Claims
What is claimed is:
1. A panel and fastener assembly comprising: a fastener having
generally parallel channel-shaped grooves, each groove having a
bottom wall, opposed sidewalls, a mid-portion and opposed open end
portions; said panel being plastically deformed into said grooves
to define a mating region of said panel, said mating region being
against said bottom wall and said opposed sidewalls defining a
panel bottom surface adjacent said bottom wall, a first side
surface adjacent one of said opposed sidewalls and a second side
surface adjacent the other one of said opposed sidewalls, said
first side surface having a greater width at said opposed open end
portions.
2. The panel and fastener assembly of claim 1 wherein said first
side surface width increases from about said mid-portion to said
opposed open end portions.
3. The panel and fastener assembly of claim 1 wherein said first
side surface has a generally uniform width along a middle portion
of said first side surface adjacent said mid-portion and opposed
outer portions which are generally wedge-shaped.
4. The panel and fastener assembly of claim 1 wherein said mating
region is generally U-shaped in cross-section.
5. The panel and fastener assembly of claim 1 wherein said fastener
opposed sidewalls are inclined inwardly to form a restricted groove
opening.
6. The panel and fastener assembly of claim 1 wherein said opposed
sidewalls and said bottom wall meet at a radiused portion.
7. The panel and fastener assembly of claim 1 wherein said fastener
includes a generally central pilot portion which cuts a slug from
and protrudes through said panel.
8. The panel and fastener assembly of claim 7 further including
opposed flange portions on opposed sides of said pilot portion,
said grooves being positioned between said pilot portion and said
flanges, said flange having panel bearing faces bearing against
said panel.
9. A method of attaching a fastener to a deformable metal panel,
said fastener having generally parallel channel-shaped grooves,
each groove having opposed sidewalls, a mid-portion and opposed
open end portions, said method comprising: locating said panel on a
die member having spaced generally parallel projecting lips adapted
to be received in said fastener grooves; locating said fastener
opposite said panel with said fastener grooves aligned with said
die member lips; driving said fastener against said panel, thereby
driving said die member lips into said fastener grooves and
deforming portions of said panel into said fastener grooves; and
said die member lips substantially simultaneously driving said
panel portions in said fastener grooves longitudinally toward said
open end portions of said grooves and laterally toward said
sidewalls of said grooves.
10. The method of attaching a fastener to a deformable metal panel
as defined in claim 9, wherein said method includes deforming said
panel portions in said fastener grooves laterally to a greater
extent as said panel portions approach said open end portions of
said grooves, forming opposed wedge-shaped bottom walls in said
panel portions engaging a bottom wall of said fastener grooves and
said sidewalls at said grooves.
11. The method of attaching a fastener to a deformable metal panel
as defined in claim 9, wherein said method includes deforming said
bottom walls of said panel portions laterally from adjacent said
mid-portion of said grooves, forming opposed wedge-shaped portions
extending from adjacent said mid-portions of said grooves.
12. The method of attaching a fastener to a deformable metal panel
as defined in claim 10, wherein said method includes deforming said
bottom walls of said panel portions laterally from a location
spaced from said mid-portion of said grooves, forming opposed
wedge-shaped portions adjacent said open end portions of said
grooves.
13. The method of attaching a fastener to a deformable metal panel
as defined in claim 9, wherein at least one of said groove
side-walls of each of said grooves is inclined inwardly, said
method including forming said panel portion laterally beneath said
inclined sidewalls of said grooves.
14. A method of attaching a fastener to a deformable metal panel,
said fastener having generally parallel channel-shaped grooves,
each groove having a bottom wall, opposed side walls, a mid-portion
and opposed open end portions, said method comprising: locating
said panel on a die member having spaced generally parallel
projecting lips configured to be received in said fastener grooves;
locating said fastener opposite said panel with said fastener
grooves aligned with said die member lips; driving said fastener
against said panel, thereby driving said die member lips into said
fastener grooves and deforming portions of said panel into said
fastener grooves against said bottom walls of said grooves; and
driving said panel portions in said fastener grooves longitudinally
toward said open end portions of said grooves and laterally toward
said side walls of said grooves adjacent said open end portions
forming opposed generally wedge-shaped bottom walls in said panel
portions engaging said bottom wall of said grooves.
15. The method of attaching a fastener to a deformable metal panel
as defined in claim 14, wherein said method includes deforming said
bottom walls of said panel portions laterally from adjacent said
mid-portion of said grooves, forming said opposed wedge-shaped
portions in said bottom walls of said panel portions extending from
adjacent said mid-portion of said grooves.
16. The method of attaching a fastener to a deformable metal panel
as defined in claim 14, wherein said method includes deforming said
bottom walls of said panel portions laterally from a location
spaced from said mid-portion of said groove forming said opposed
wedge-shaped portions adjacent said open end portions of said
grooves.
17. A die member comprising: a body having an end face; a pair of
opposed clinching lips protruding from said end face, said
clinching lips being generally parallel to one another; said
clinching lips having a generally flat end surface for engaging a
panel to which a fastener is to be installed, a base which is
integral to said end face and an outer sidewall, said sidewall
joining said end surface and said base, said end surface having a
mid-point and opposed ends with said end surface being wider at
said mid-point than at said opposed ends, and said base being wider
than said end surface.
18. The die member of claim 17 wherein said end surface narrows
gradually from about said mid-point to said opposed ends.
19. The die member of claim 17 wherein said end surface begins to
narrow gradually a spaced distance on either side of said
mid-point.
20. The die member of claim 17 further including an opening
extending through said body and said end face.
21. The die member of claim 20 further including inner sidewalls
spaced from said outer sidewall, said inner sidewalls positioned
about said opening.
22. The die member of claim 17 further including a pair of opposed
staking lips protruding from said end face, said staking lips being
generally parallel to one another and generally perpendicular to
said clinching lips.
23. The die member of claim 22 wherein said staking and clinching
lips are joined at this free end by corners to form a continuous
protrusion.
Description
1. This application claims the benefit of U.S. Provisional
Application No. 60/083,578, filed on Apr. 30, 1998.
BACKGROUND OF THE INVENTION
2. The present invention relates to die members, panels and
fastener assemblies and methods for the installation of fasteners
into a workpiece such as for example panel metal. More
particularly, the present invention relates to an improved die
member and method of installation that provides a better fastener
installation and has a much longer life than previous die members.
The main objective of the die member of the present invention is to
reduce the stress on and breakage of the die member that was
experienced by conventional die members, and to push more metal
into the groove of the fastener to provide a more secure
attachment.
3. The die member of the present invention is used in a fastener
installation process shown generally in for example U.S. Pat. No.
4,630,363. The die member typically sits below the panel into which
a fastener is to be installed and is mounted in the bottom platen
of a press. An installation head which holds the fastener to be
installed is mounted to the upper press platen and positioned on
the other side of the panel. When the press closes, the
installation head drives the fastener into the panel and the die
member causes the panel to be deformed into the locking grooves and
around the ends of the fastener.
4. One difficulty with standard die members is that the die members
can break during the installation process. This results in a bad
installation in the panel and the need to stop the press to replace
the die member. As will be appreciated by those of ordinary skill
in the art, when a press is shut down the cost in lost production
time can be considerable. Therefore, a die member that has
increased life will result in less downtime and increased
production capabilities for each press.
SUMMARY OF THE INVENTION
5. The present invention overcomes the above difficulties
experienced in standard die buttons and fastener and panel
assemblies. The die button of the present invention has an end face
with a pair of opposed clinching lips which protrude from the end
face. The clinching lips are generally parallel to one another and
have a generally flat end face for engaging a panel to which a
fastener is to be installed. The clinching lips include a base
which is integral to the end face of the die member and an outer
sidewall which joins the end surface and the base. The end surface
has a mid-point and opposed ends with the end surface being wider
at the mid-point than at the ends and the base is wider than the
end surface. The die button is used to attach a fastener having
opposed, parallel grooves to a panel metal. The grooves have a base
and sidewalls. The die member generally mates with these grooves
and drives panel material into these grooves to fill the grooves.
The configuration of the clinching lips of the die member is such
that the panel metal is plowed from adjacent the mid-point to the
sides of the groove and to the ends of the groove to completely
fill the groove and still maintain the die button integrity.
6. In one embodiment, the die button end surface narrows gradually
from about the mid-point to the opposed ends. In another embodiment
the end surface begins to narrow gradually a spaced difference on
either side of the mid-point.
7. The invention further teaches a novel panel and fastener
assembly which comprises a fastener having generally parallel
channel-shaped grooves with each groove having a bottom wall,
opposed sidewalls, a mid-point portion and opposed open end
portions. The panel is plastically deformed into these grooves to
define a mating region of the panel. The mating region is forced
against the bottom wall and opposed side walls of the grooves. The
mating region defines a panel bottom surface adjacent the bottom
wall, a first side surface adjacent one of the opposed sidewalls
and a second side surface adjacent one of the other opposed
sidewalls. The first side surface has a greater width at the
opposed open end portions than at the mid portion.
8. In one embodiment, the first side surface width of the panel
metal increases from about the mid-point to the opposed open end
portion. In a second embodiment, the first side surface of the
panel metal has a generally uniform width along a middle portion of
the first side surface adjacent the mid portion and opposed outer
portions which are generally wedge-shaped.
9. The present invention also discloses a method of attaching a
fastener to a deformable metal panel by locating the panel on a die
member having spaced generally parallel projecting lips adapted to
be received in the fastener grooves of the fastener. A fastener is
located opposite the panel with the fastener grooves aligned with
the die member lips. The fastener and panel are driven together
driving the die member lips into the fastener grooves shearing a
slug and deforming portions of the panel into the fastener grooves.
The die member lips substantially simultaneously drive the panel
portions in the fastener grooves longitudinally toward the open end
portions of the grooves and laterally toward the sidewalls of the
grooves.
10. Other advantages of the present invention will be readily
appreciated as the same becomes better understood by reference of
the following detailed description when considered in connection
with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
11. FIG. 1 is a perspective view of the die button, panel and
fastener of the present invention;
12. FIG. 2 is a top view of the die button of FIG. 1;
13. FIG. 3 is a cut-away view taken along lines 3-3 of FIG. 2;
14. FIG. 4 is a cut-away view taken along lines 4-4 of FIG. 2;
15. FIG. 5 is a cut-away view taken along lines 5-5 of FIG. 2;
16. FIG. 6 is a top view of a second embodiment of the design
button of the present invention;
17. FIG. 7 is a cut-away view taken along lines 7-7 of FIG. 6;
18. FIG. 8 is a cut-away view taken along lines 8-8 of FIG. 6;
19. FIG. 9 is a cut-away view of the die button of FIG. 2, panel
and fastener of the present invention; and,
20. FIG. 10 is a top view of FIG. 9.
DETAILED DESCRIPTION OF THE INVENTION
21. FIG. 1 shows a pierce nut 20 of the type used with the die
member 24 of this invention, ready for installation in a panel 22
by die member 24. The illustrated pierce nut includes a central
rectangular pilot portion 26 having a flat top piercing face 28,
end walls 30 generally perpendicular to the top face 28 of the
pilot and integral flange portion 32 on opposed sides of the pilot.
The flange portions 32 include top panel bearing faces 34 spaced
below the plane of the top face 28 of the pilot, and parallel
grooves 36 on opposed sides of the pilot 26 is extending
perpendicular to the end walls 30 of the nut.
22. It will be understood that "top" and "bottom" are relative
terms and are used herein for purposes of description only.
Further, the pierce nut, panel and die member are arranged in the
drawings to illustrate the method of forming the nut and panel
assembly of this invention. In actual use, the die member 24 will
generally be the lower or bottom element and the pierce nut is
moved downwardly by the pierce nut installation head to form the
nut and panel assembly. As will be appreciated by those of ordinary
skill in this art, a pierce nut is generally installed by a pierce
nut installation head in a die press assembly. The panel may be
simultaneously formed in the die press, particularly in automotive
applications, and several pierce nuts may be simultaneously
installed in the panel, in one stroke of the press. FIG. 1,
however, illustrates a commercial application, regardless of
whether the pierce nut 20 is located above or below the die member
24, with the panel 22 located therebetween.
23. The parallel grooves 36 each include an inner side wall 38, a
bottom wall 40 and an outer side wall 42. In the disclosed
embodiment of the pierce nut 20, the grooves are re-entrant,
wherein one or both of the inner and outer side walls, 38 and 42,
respectively, are inclined inwardly, toward the longitudinal axis
of the groove, to form a restricted groove opening. The re-entrant
grooves entrap the panel metal deformed into the grooves
substantially improving nut retention, as described in U.S. Pat.
No. 3,648,747, which is included herein by reference.
24. The disclosed pierce nut 20 includes a central threaded bore 44
having an axis generally perpendicular to the top face 28 of the
pilot 26. In the disclosed embodiment of the pierce nut, the pilot
also includes side walls 38 perpendicular to the top face 28 of the
pilot, and the sides 48 of the flanges are truncated primarily to
reduce the weight or mass of the pierce nut. The bottom face 50 of
the pierce nut is preferably flat and generally parallel to the top
face 28 of the pilot. The bottom face 50 is engaged by a plunger of
an installation apparatus or head (not shown) to form the nut and
panel assembly; see also U.S. Pat. Nos. 3,108,368 and 3,969,808,
which disclose suitable installation heads which may be utilized to
form the nut and panel assembly of this invention. Both of the
above-referenced patents are assigned to the assignee of the
present application and the disclosures are incorporated herein by
reference.
25. The die member of the present invention is shown generally at
24 in FIG. 1 and the face of the die member 24 is shown in FIG. 2.
The die member 24 has a body 25 and an end face 64. The end face is
shown in FIG. 2. An opening 52 is formed for receipt of the slug
formed by the pierce nut 20 cutting through the panel 22. The face
64 has lips 60 and 62 which drive panel metal into the grooves 36
of the fastener 26 and along end faces 30. The lips 60 are staking
lips which keep the fastener from moving with respect to panel 22
when the fastener 20 is installed. The staking lips 60 are
generally parallel to one another. The lips 62 are clinching lips
which clinch the panel metal into the grooves of the fastener 20.
The end surface 61 of lips 60 and 62 is generally flat.
26. The lips 62 are angled with respect to the vertical and
horizontal axes. As illustrated in FIGS. 3 through 5, the sides of
the lips 62 are angled with respect to the die vertical axis
between 10.degree.and 20.degree. and preferably at about
15.degree., see arrows a-a, in FIG. 3. As illustrated in FIG. 2,
the sides of the lips 62 are also angled with respect to the
horizontal axis between 1.degree.and 10.degree.and preferably at
about 5.degree., see arrows b-b in FIG. 2. The angle of the lips 62
in two planes facilitates enhanced packing of metal into the groove
of the fastener 20, which will be discussed in greater detail
below.
27. The lips 60 are angled with respect to the contact face 61
between 40.degree.and 50.degree.and preferably at about 45.degree..
The inner corners 68 of the die member lips are radiused and the
outer corners 70 of the lips are angled at approximately the same
angle to the vertical as lips 60. The contact face 61 of the lips
60 and 62 is generally flat to provide a greater surface area to
force panel metal into the grooves 36 and provide a larger surface
area to reduce the contact pressure acting on the lips 60, 62.
28. The packing of the metal into the grooves 36 is illustrated in
FIGS. 3 through 5 and FIG. 10. The illustration in FIG. 3 is a
section taken along lines 3-3 of FIG. 2; FIG. 4 is a section taken
along lines 4-4 of FIG. 2 and FIG. 5 is a section taken along lines
5-5 of FIG. 2. As illustrated in FIG. 3, the lip is wider than the
lip in FIGS. 4 and 5. The lip 62 is widest at the midpoint of the
lip, at line 3-3, and becomes narrower as it extends to the
corners. This narrowing of the lips 62 causes metal to be plowed
from the mid-point 80 to the ends 82 of the groove 36 of the
fastener 20 to better fill the groove, see FIG. 10, arrow C. The
angle of the lips with respect to vertical also facilitates the
movement of the metal within the groove and plows metal from the
center to the outer side of the groove, see FIG. 10, arrow D. As
illustrated, the wider lip at section 3-3 leaves less room between
the lip at 3-3 and the walls 38 and 42 of the fastener 20. Because
there is less room, the panel metal at this location must be
displaced elsewhere and the path of least resistance is to the
wider areas towards the ends of the lips, i.e., sections 4-4 and
sections 5-5. Therefore, the metal is plowed or pushed away from
the midpoint of the lip to fill the entire groove 36.
29. The panel 22 includes a mating region 72 which is driven into
mating contact with grooves 36 by lips 62. The mating region 72
includes a panel bottom 74, first side surface 76 and second side
surface 78. As illustrated, the panel 22 in the mating region 72 is
forced under the inwardly extending sidewalls 38 and 42, in other
words, the grooves 36 are filled with the mating region 72.
30. The cross-sections in FIGS. 3 through 5 are taken along the
corresponding lines in FIG. 2 to illustrate the increasing width of
the first side surface 76 as its distance increases from the
general midpoint 80 of groove 36, to the opposed ends 82 of groove
36. In the preferred embodiment, a flat surface 79 is provided for
facilitating tooling and dimensioning of the die button. Other than
the flat surface 79, the sidewall 62 is angled.
31. In use, the fastener is fed into an installation head, such as
for example, the installation head disclosed in U.S. Pat. No.
5,487,215. The installation head is mounted to the platen of a
press with the die member mounted to the opposite platen. Sheet
metal 22 is mounted upon the die member and the press closes,
driving a fastener from the installation head into the panel and
the die member. The lips 60 and 62 are driven into the grooves 36
and adjacent end walls 30 deforming metal into the grooves 36 and
along side the end walls 30. A slug is pierced from the panel by
the end face 28 of the pilot and the pilot 26 is received through
the pierced panel opening.
32. The stress on typical die member lips is about 600,000 to
700,000 PSI. A typical die member with forces in this range is
disclosed in U.S. Pat. No. 4,630,363. In previous die members
manufactured by applicant, the contact face of the clinching lips
were about 0.019 inches wide resulting in the potential for broken
die members because of the high forces per square inch. In the
disclosed embodiment, the contact face of the clinching lips at the
midpoint is wider, approximately 0.050 inches, to reduce the forces
being applied. Additionally, the height of the lips 60, 62 is less
to better withstand the forces and facilitate filling of the groove
36. Overall, with the angled lips, flattened end faces and height
reduction, the stresses on the lips have been reduced to about
107,000 PSI which greatly extends the life of the die member. A
further benefit is the reduction of the bending stresses on the
clinch lips 62. By reshaping the clinch lips 62, the bending
stresses are reduced by 31,600 PSI, from about 152,000 PSI to about
121,000 PSI.
33. It should be appreciated that the dimensions provided are
approximate and are for the disclosed die button to obtain optimum
performance. The die button dimensions may change as a result of
the volume of the metal into which the fastener is installed and
may change depending upon the width of the groove 36 in fastener
20.
34. FIG. 9 illustrates a cross-section of the die button 24 as the
installation of the fastener to the panel completed. As
illustrated, the slug 69 has been cut from the panel 22 by the
pilot portion 26.
35. FIG. 10 is a top view of FIG. 9 illustrating the fastener 20
attached to a panel 22 on top of die member 24. The arrows C and D
illustrate the flow of metal in both the lateral direction D and
longitudinal direction C of the groove 36. As can be seen, the
metal flows in two directions from the mid-point 80 out to the ends
82.
36. Applicant has found that the die button of the first embodiment
is preferably used in low carbon, low strength stamping material.
The second embodiment discussed below is preferably used in high
strength, low alloy stamping material.
37. With reference to FIGS. 6-8, a further embodiment of the die
button of the present invention is illustrated at 85. In this
embodiment, the clinching lips 62 are angled in the same maimer as
the clinching lips 62 of the previous embodiment. However, in this
embodiment, the lips 62 are angled at a spaced distance from the
mid-portion 84 of the lip 62. As can be seen in this embodiment,
there is a wider mid-section 86 than in the previous embodiment. In
the disclosed embodiment, the mid-section 86 is approximately
5/8inches in length. The length of the mid-section 86 will vary
depending upon the fastener size that is used. The width of the
contact face 61 in this embodiment is approximately 0.059 inches.
As with the previous embodiment, the dimensions may change
depending upon the volume of the metal and the size of the groove
36. In this embodiment, the die button 85 has inclined surfaces 88
and 90 which plow metal in the same manner as the previous
embodiment, but because of the wider and longer mid-section 86,
less metal is plowed. It has been found that with a thicker section
on the lips 62, there is lower stresses in the fastener. With
greater amounts of metal being plowed, the fastener might be
deflected to accommodate the metal being moved, which is not
acceptable in many applications.
38. In the preferred embodiment, a break-away angle 92 is provided.
The break-away angle 92 is provided to avoid sticking of the lip 62
in the panel. By providing the break-away angle of about
7.degree.along the mid-section 86, the lips 62 can freely release
from the panel after the panel has been driven into the grooves
36.
39. The invention has been described in an illustrative manner, and
it is to be understood that the terminology which has been used is
intended to be in the nature of words of description rather than
limitation.
40. Obviously, many modifications and variations of the present
invention are possible in light of the above teachings. It is,
therefore, to be understood that within the scope of the appended
claims, the invention may be practiced otherwise than as is
specifically described.
* * * * *