Note: Descriptions are shown in the official language in which they were submitted.
CA 02501754 1999-10-20
SELF-PIERCING CLINCH NUT
1 BACKGROUND OF THE INVENTION
2 The present invention generally relates to self-
3 attaching fasteners and, more specifically to clinch nuts
4 and installation tooling therefor.
Self-attaching fasteners are used in many industries
6 such as, for example, the automotive and appliance
7 industries to secure various components to metal panels.
8 When clinch nuts are attached to the metal panels, screws
9 or bolts are threaded into the clinch nuts and tightened
to prescribed torque values. During installation, the
11 clinch nuts must have sufficient rotational resistance to
12 keep them from rotating relative to the metal.panels when
13 the screws are inserted and tightened. During service,
14 the clinch nuts must have sufficient pull-through
resistance to keep them from pulling out of the metal
16 panel when external forces such as, for example, vibration
17 or other tensile forces are applied.
18 A clinch nut typically includes a central pilot or
19 punch portion which at least partially extends into an
opening in a metal.plate or panel. When the clinch nut is
21 self piercing, the central pilot portion cooperates with
22 tooling to form the opening in the metal panel when
23 attaching the clinch nut to the metal panel. The clinch
24 nut is attached to the metal panel by a die member which
forms a mechanical interlock between the clinch nut and
26 the metal panel. The die member typically deforms the
27 metal panel about the opening into an annular groove of
28 the clinch nut which encircles the pilot portion and/or
29 deforms the pilot portion of the clinch nut over the metal
panel to entrap the metal panel.
31 For example, U.S. Patent No. 3,053,300 discloses a
32 clinch nut having a central pilot portion which extends
33 through a pre-formed opening in a metal panel and is
34 folded over to stake the periphery of the opening. The
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2
1 deformation of the central pilot forces the metal panel to
2 conform to an undulating surface of the annular groove and
3 to form the interlock between the clinch nut and metal
4 panel. While this clinch nut may have a relatively high
pull-out resistance, the deformation of the central pilot
6 can easily distort the internal threads of the clinch nut.
7 One approach to eliminate distortion of the internal
8 threads when deforming the pilot is to deform the metal
9 panel to form the interlock rather than the pilot of the
clinch nut. For example, U.S. Patent Nos. 3,878,599 and
11 4,690,599 each disclose a clinch nut having an undercut on
12 either the inner or outer wall of the groove. Material of
13 the metal panel is forced into the undercut to improve the
14 interlock formed between the clinch nut and the metal
panel. With relatively thin metal panels, however, very
16 little material is forced into the undercut, resulting in
17 a relatively low pull-out resistance.
18 One approach to increase the pull-out resistance of
19 clinch nuts of this type is to form a double-undercut
groove. For example, U.S. Patent No. 5,340,252 discloses
21 a clinch nut having undercuts in both the inner and outer
22 walls so that the annular groove is "dove-tail" shaped in
23 cross section. The metal panel is farced into both of the
29 undercuts to form an improved interlock between the clinch
nut and metal panel. The deformation of the metal panel
26 required to fill both undercuts, however, is difficult to
27 obtain using conventional forming techniques, resulting in
28 inconsistent pull-out resistance.
29 An additional problem with the above-noted self-
clinching fasteners is that~they typically do not
31 function well with thin metal panels, that is, panels of
32 3 mm or less. Accordingly, there is a need in the art
33 for an improved clinch nut which can be reliably and
34 consistently attached to a thin metal panel having
CA 02501754 1999-10-20
r
_ s
3
I sufficient pull-out strength, sufficient rotational
2 resistance, and without having distortion of the internal
3 threads: Additionally, there is a need for an improved
4 die member for installing a clinch nut in a thin metal
panel having sufficient pull-out strength, having
6 sufficient rotational resistance, and without having
7 distortion of the internal threads. Furthermore, there is
8 a need for both the clinch nut and the die member to be
9 relatively inexpensive to produce and relatively easy to
use.
11 BRIEF SUMMARY OF THE INVENTION
I2 The present invention provides a self-clinching
13 fastener for attachment to a plastically deformable metal
14 panel, which overcomes at least some of the above-noted
problems of the related art. According to the present
16 invention, the self-clinching fastener includes a body
17 portion with a central axis and a central pilot or punch
18 portion extending from the body portion and coaxial with
19 the central axis. The body portion forms a generally
annular-shaped end face adjacent the central pilot portion
21 and a groove defined in the end face encircling the
22 central pilot portion. The groove has an inclined inner
23 wall forming an undercut and an inwardly inclined bottom
24 wall such that the groove has an increasing depth in a
direction toward the undercut. The inclined bottom wall
26 is formed by a plurality of generally flat faces, and a
27 plurality of spaced apart lugs encircling the central
28 pilot portion and axially extending from at least one of
29 the end face and the groove. The lugs form abutments to
improve torsional resistance of the fastener.
3I According to another aspect of the present
32 invention, the self-clinching fastener includes a body
33 portion with a central axis and a central pilot portion
34 extending from the body portion and coaxial with the
central axis. The body portion forms a generally
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~ 4
Z annular-shaped end face adjacent the central pilot
2 portion and a groove defined in the end face encircling
3 the central pilot portion. The groove has an inner wall
4 formed by a plurality of generally flat faces and a
bottom wall formed by a plurality of generally flat
6 faces. The faces of the bottom wall are aligned with the
7 faces of the inner wall. A plurality of spaced apart
8 lugs encircle the central pilot portion and axially
9 extend from at least one of the end face and the groove.
The lugs form abutments to improve torsional resistance
11 of the fastener. Preferably, the groove further includes
12 an outer wall formed by a plurality of generally flat
13 faces aligned with the faces of the inner wall and the
14 bottom wall.
According to yet another aspect of the present
16 invention, a method of attaching a self-clinching
17 fastener to a plastically deformable metal panel includes
18 coaxially positioning the fastener and a die member on
19 opposite sides of the metal panel at a position in which
the fastener is to be secured to the metal panel. The
21 fastener and the die member are oriented so that a
22 plurality of inclined faces in a groove of the fastener
23 and a cooperating plurality of inclined faces of the die
24 member are circumferentially aligned. The die member and
the fastener are then relatively moved toward one another
26 in an axial direction to deform a portion of the panel
27 into the groove of the fastener by coining the panel
28 between the inclined faces of the fastener and the
29 inclined faces of the die member and on opposite sides of
lugs configured to improve torsional-resistance of the
31 fastener until a secure mechanical interlock is formed
32 between the fastener and the panel.
33 According to even yet another aspect of the present
34 invention, a self-clinching fastener for attachment to a
plastically deformable metal panel includes a body
36 portion with a central axis and a central pilot portion
37 extending from the body portion and coaxial with the
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1 central axis. The body portion forms a generally
2 annular-shaped end face adjacent the central pilot
3 portion and a groove defined in the end face encircling
4 the central pilot portion. The groove has an inclined
inner wall forming an undercut and an inwardly inclined
6 bottom wall such that the groove has an increasing depth
7 in a direction toward the undercut. The inclined bottom
8 wall is inclined at an angle greater than 2 degrees and
9 less than about 50 degrees relative to a plane
perpendicular to the central axis. The fastener further
il includes a plurality of spaced apart lugs encircling the
12 central pilot portion and axially extending from at least
13 one of the end face and the groove. The lugs form
14 abutments to improve torsional resistance of the
fastener. Preferably, the inclined~bottom wall is
16 inclined at an angle of about 20 degrees relative to the
17 plane perpendicular to the central axis.
18 BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
19 These and further features of the present invention
2o will be apparent with reference to the following
21 ~ description and drawings, wherein:
22 FIG. 1 is a perspective view of a clinch nut
23 according to a first embodiment of the present invention;
24 FIG. lA is a perspective view of a clinch nut
according to a variation of the clinch nut of FIG. 1;
26 FIG. 2 is a top plan view of the clinch nut of FIG.
27 1;
28 FIG. 3 is a sectional view taken along line 3-3 of
29 FIG. 2;
FIG. 3A is a sectional view similar to FIG. 3 but of
31 the clinch nut of FIG lA;
32 FIG. 4 is a bottom plan view of die for installing
33 the clinch nut according to the present invention;
34 FIG. 5 is a sectional view taken along line 5-5 of
FIG. 4;
36 FIGS. 6A to 6C are elevational views, in cross-
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6
1 section, showing various stages of installation of the
2 clinch nut of FIG. 1 using the die of FIG. 4;
3 FIG. 7 is a perspective view of a clinch nut
4 according to a second embodiment of the present
invention;
6 FIG. 8 is a top plan view of the clinch nut of FIG.
7 7;
8 FIG. 9 is a sectional view taken along line 9-9 of
9 FIG. 8;
FIG. 10 is a perspective view of a clinch nut
11 according to a third embodiment of the present invention;
12 FIG. 11 is a top plan view of the clinch nut of FIG.
13 10;
14 FIG. 12 is a sectional view taken along line 12-12
of FIG.
11;
16 FIG. 13 is a perspective view of a clinch nut
17 according to a fourth embodiment of the present
18 invention;
19 FIG. 14 is a top plan view of the clinch nut of FIG.
13;
21 FIG. 15 is a sectional view taken along line 15-15
22 of FIG. ;
14
23 FIG. 16 is a perspective view a clinch nut according
24 to a fifth
embodiment
of the
present
invention;
FIG. 17 is a top plan view of the clinch nut of FIG.
26 16;
27 FIG. 18 is a sectional view taken along line 18-18
28 of FIG. ;
17
29 FIG. 19 is a perspective view of a clinch nut
according to a
sixth
embodiment
of
the
present
invention;
31 FIG. 20 is a top plan view of the clinch nut of FIG.
32 19;
33 FIG. 21 is a sectional view taken along line 2I-21
34 of FIG. ;
20
FIG. 22 is a perspective view of a clinch nut
36 according to a
seventh
embodiment
of
the
present
37 invention;
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7
1 FIG. 23 is a top plan view of the clinch nut of FIG.
2 22; and
3 FIG. 24 is a sectional view taken along line 24-24
4 of FIG. 23.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
6 FIGS. 1-3 illustrate a self-piercing clinch nut 10
7 according to a first embodiment of the present invention
8 for attachment to a plastically deformable metal plate or
9 panel. It is noted that while the illustrated embodiment
is a nut, other self-clinching fasteners such as, for
11 example, self-clinching studs are within the scope of the
12 present invention The clinch nut 10 has a body portion
13 12 and a pilot or punch portion~l4 extending from one end
14 of the body portion 12, and a threaded hole or bore 16
axially extending through both the body portion 12 and
16 the punch portion 14.
17 The punch portion 14 is generally smaller than the
18 body portion 12 to form a generally annular-shaped
19 surface or end face 18 for engaging a metal panel as
described in more detail hereinafter. The panel-engaging
21 surface 18 is preferably substantially perpendicular to
22 the central axis 20. A generally annular-shaped groove
~3 22 is formed in the panel-engaging surface 18 and is
24 preferably adjacent and/or contiguous with the punch
portion 14. The groove 22 preferably does not extend to
26 the outer edge of the panel-engaging surface 18 so that
27 the panel-engaging surface 18 forms a lip 24 at the outer
28 periphery of the groove 22. The lip 24 is a narrow
29 bearing surface band which, while uniform in width,
presents a continuously variable radial swept area to
31 maximize the torsional integrity of the clinch nut 10.
32 The groove 22 is preferably formed by a bottom wall 26,
33 an inner wall 28, and an outer wall 30.
34 The illustrated bottom wall 26 is inwardly angled or
inclined toward the inner wall 28, that is the groove 22
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1 increases in depth when radially moving from the outer
2 periphery of the bottom wall 2.6 to the inner periphery of
3 the bottom wall 26.- The bottom wall 26 is preferably
4 inclined at an angle of greater than 2,degrees and less
than about 50 degrees relative to a plane perpendicular
6 to the central axis 20, is more preferably at an angle of
7 greater than 5 degrees and less than about 50 degrees
8 relative to a plane perpendicular to the central axis 20,
9 is even more preferably at an angle of about 10 degrees
to about 45 degrees relative to a plane perpendicular to
11 the central axis 20, and is most preferably at an angle
12 of about 20 degrees relative to a plane perpendicular to
13 the central axis 20. It should also be obvious that the
14 bottom wall 26 could contain a variety of inclined angles
relative to one another on'a single nut 10. The angled
i6 or inclined bearing surface maximizes the extent to which
17 the work-piece cooperates with.the clinch nut 10 to
18 resist axial.loads which tend to separate the two
19 components. Increasing the angle increases the depth of
the groove 22 and therefore the length of the punch.
21 This ~~punch length extension" allows the clinch nut to be
22 secured to work-piece thicknesses well below prior art
23 clinch nuts, that is, the clinch nut can be secured to
24 work-pieces having thicknesses below 1.63 mm. If the
angle gets too large, however, the length of the body
26 portion 12 must be increased and tooling problems are
27 created in forming the groove.
28 The bottom wall 26 is preferably polygonally-shaged
29 wherein it is formed by a plurality of angled or
inclined; planer or flat faces or facets 32. The bottom
31 wall 26 is preferably formed by about 6 to about to of
B2 the faces 32, and is more preferably formed by about 8 of
33 the faces 32. The polygonal-shape provides a non-uniform
34 shape which constricts or coins the work-piece material
during the clinch-nut setting process, thereby generating
36 enhanced push-out resistance and torque-out resistance as
37 described in more detail hereinafter. The bearing area
CA 02501754 1999-10-20
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1 is increased by increasing the number of the faces 32
2 (note the optimum bearing area is a cone)-but this
3 decreases the torsional resistance. When more than 10 of
4 the faces 32 are used, the bearing surface begins to
approximate a cone. When less than,6 of the faces 32 are
6 used, too little bearing surface is available for
7 adequate bearing loads. The octagon-shape using 8 of the
8 faces 8 is a balance point between these two competing
9 requirements.
The illustrated inner wall 28 is inwardly angled or
11 inclined such that the groove 22 forms an undercut in the
12 punch portion 14. The inner wall 28 is also preferably
13 polygonally-shaped wherein it is formed by a plurality of
14 angled or inclined, planar or flat faces or facets 34.
The inner wall 28 is preferably formed by about 6 to
16 about 10 of the faces 34, and is more preferably formed
17 by about 8 of the faces 34. As illustrated, the inner
.18 wall 28 is most preferably formed by the same number of
19 faces 34 as the bottom wall 26 and the faces 34 of the
inner wall 28 are preferably circumferentially aligned
21 ~ with the faces 32 of the bottom wall 26 and the outer
22 wall 30.
23 ~_ The illustrated outer wall 30 is substantially
24 perpendicular to the panel-engaging surface 18, that. is,
the outer wall 30 is substantially parallel with the
26 central axis 20. The outer wa11.30 is also preferably
27 polygonally-shaped.wherein it is formed by a plurality of
28 planar or flat faces or facets 36. The polygonal shape
29 of the outer wall 30 enhances torsional resistance
because the outer wall 30 must plow through work-piece
31 material for the clinch nut to rotate relative to the
,32 work-piece. The outer wall 30 is preferably formed by
33 about 6 to about 10 of~ the faces 36 and is more
34 preferably formed by.about 8 of the faces 36. As
illustrated, the outer wall 30 is most preferably formed
36 by the same number of faces 36 as the bottom and inner
37 walls 26, 28 and the faces 36 of the outer wall 30 are
CA 02501754 1999-10-20
1 preferably circumferentially aligned with the faces 32,
2 34 of the bottom and inner walls 26, 28. It is noted
3 that the outer wall 30 can alternatively have other
4 configurations within the~scope of the present invention
5 and can even be eliminated'by extending the bottom~wall
6 26 to the panel-engaging surface 18 or lip 24 (for
7 example, see alternative embodiments illustrated in FIGS.
8 to 10-21).
9 The illustrated body portion 12 has an outer
10 periphery which is polygonally-shaped wherein it is
11 formed by a plurality of planar~or flat faces or facets
12 38. The outer periphery is preferably formed by about 6
13 to about 10 faces 38, and is more preferably formed by
14 about 8 faces 38. As illustrated, the outer.periphery is
preferably formed by the same number of faces 38 as the
16 walls 26, 28, 30 of the groove 22 and the faces 38 of the
17 outer periphery are preferably circumferentially aligned
18 with the faces 32, 34, 36 of the groove walls 26, 28, 30.
19 It is noted, however, that the outer periphery of the
body portion 12 can alternatively have other
21 configurations within the scope of the present invention
22 such as, for example, cylindrical. The length of the
23, body portion 12 is sized to provide sufficient thread
~24 engagement to consistently break (without stripping the
threads) the mating externally threaded member whose
26 material strength properties are matched to those of the
27 clinch nut 10.
28 ' In the illustrated embodiment, the inner wall 28 of
29 the groove 22 is~contiguous with the outer periphery of
the punch portion 14 so that the inner wall 28 generally
31 forms the outer periphery of the punch portion 14. It is
32 noted, however, that the outer periphery of the punch
33 portion 14 can have other configurations within the scope
34 of the present invention. The outer or free end of the
punch portion 14, which~is opposite the body portion 12,
36 has a piercing or shearing edge 4o formed thereon. As
37 described in more detail hereinafter,'the shearing edge
CA 02501754 1999-10-20
. I1
1 40 cooperates with a die member to perforate or shear a
2 metal plate or panel during installation of the clinch
3 nut 10 in the metal panel. The length of the punch
4 portion 14 is preferably sized to accommodate the work-
s piece material thickness without protruding beyond the
6 plane formed by the back side of the work-piece as
7 described in more detail hereinafter. The diameter of
8 the punch portion 14 is preferably sized to provide
9 sufficient column strength to allow the clinch nut 10 to
to punch its own hole into materials up to 3 mm thick at a
' 11 maximum hardness of 60 on the Rockwell C hardness scale
12 (approximately 50,000 p.s.i. ultimate tensile strength of
13 the work-piece material). It should be obvious that for
14 thinner and/or softer materials, these maximum values
15 would be increased. It should also be obvious that for
16 thicker materials and/or harder materials, the punch
. 17 portion geometry can be sized to accommodate the.
18 requirements of those work-pieces.
19 The clinch nut 10 also includes a plurality of
20 locking members or lugs 42~for increasing the torque or
21 rotational resistance of the clinch nut 10. The lugs 42
22 .are raised lobes or protuberances which axially extend
23 above the panel-engaging surface l8, the groove 22, or
24 the lip 24 and circumferentially extend over a limited
25 distance such that abutments 43 are formed which impede'
26 or resist rotation of the clinch nut 10 relative to the
27 metal panel. The abutments 43 are preferably
28 perpendicular to the rotational motion of the nut. In
29 the illustrated embodiment, the lugs 42 are formed by
30 protuberances which axially extend above the groove
31 bottom wall 26 and radially extend across the groove 22
32 from the groove inner wall 28 to the groove outer wall
33 30. The upper sides of the lugs 42, which are the sides
34 opposite the bottom wa11~26, are generally perpendicular
35 to the central axis 20 and are generally parallel to the
36 lip 24~but are preferably recessed below the lip 24. The
37 lugs 42 are preferably circumferentially spaced apart
CA 02501754 1999-10-20
12
1 along the bottom wall 26 and there is preferably a lug 42
2 centrally located on each face 32 of the bottom wall 26.
3 It is also noted, however, that the lugs 42 may be
4 located at other positions such as the interface between
adjacent faces 32 of the bottom wall 26. The cross-
6 sectional shape of the illustrated lugs 42 is
7 rectangular. The cross-sectional shape of the lugs 42,
8 however, may be any other suitable shape.
9 It is noted that adjacent faces 32 of the bottom
wall 26 may alternatively be joint-free at the corners of
il the nut body portion 12 and jointed at the radial
12 centerlines of the lugs 42. This alternative may give
13 the area of the groove 22 increased torsional loading
14 resistance because the abutments 43 would be axially
larger and therefore give more torsional resistance.
16 For example, an acceptable clinch nut 10 having a
17 thread size of M10x1.5 and for work pieces having a
18 minimum thickness of 0.050 inches (1.27 mm) can have a
19 bottom wall 26 with eight facets 32 inclined at an angle
of about 20°. The facets 32 are aligned with eight
21 facets 34 of the punch portion inner wall 28, eight
22 facets 36 of the outer wall 30, and eight faces 38 of the
23 body portion outer periphery. The outer wall 3o has a
24 height of about .015 inches to about .025 inches. The
body portion is about .712 to about .730 inches across
26 corners, is about .666 to about .674 inches across flats,
27 and has a height of about .314 to about .318 inches. The
28 distance between inner edges of the lip 24 is about .600
29 to .606 inches. The punch portion 14 has a height of
about .043 to about .047 inches above the lip 24, a
31 diameter of about .514 to about .518 inches, and a base
32 diameter at the bottom wall of about .484 inches maximum.
33 The lugs 42 have a width of about .058 to about .081
34 inches.
FIGS. 4 and 5 illustrate a die member 44 according
36 to the present invention which is used to attach the
37 clinch nut l0 to a metal panel or plate. The die member
CA 02501754 1999-10-20
. 13
1 44 has a generally cylindrical-shaped body 46 with a~
2 panel-engaging end face or surface 48 which is
3 substantially perpendicular to the central axis 50. An
4 axially extending central bore or opening 52.forms a
piercing or shearing edge 54 at the inner edge of the
6 panel engaging end face 48. The shearing edge 54 is
7 sized and shaped to cooperate with the shearing edge 40
8 of the clinch nut 10 (FIGS. 1-3) to perforate or shear a
9 metal plate or panel during installation of the clinch
nut l0 in the metal panel., The generally annular-shaped
11 engagement end face 48 is sized to cooperate with and/or
12 extend into the groove 22 of the clinch nut 10. Although
13 in some instances the end face 48 may be sized to
14 cooperate with the surface 18 to create a constriction
aid pinching action upon the panel 58 thereby trapping
16 and further compacting the metal pane1.58 into the groove
17 22. Adjacent the. panel-engaging end face 48 area
18 plurality of angled or inclined, planar or flat faces or
19 facets 56. It is noted that the outer periphery of the
panel-engaging end face 48 is polygonally-shaped due to
21 the inclined faces 56. In the illustrated embodiment,
22 the outer edge of the panel-engaging end face 48 is
23 octagonal while the inner or shearing edge 54 is
24 circular. It should be obvious that for simplicity of
manufacturing of the die member 44, the outer edge of end
26 face 48 could be round and the inclined faces 56 could be
27 one contiguous conical surface.
28 The quantity of the faces 56 of the die member 44 is'
29 the same as the quantity of the faces 32 on the bottom
wall 26 of the clinch nut l0 (FIGS. 1-3) to be installed
31 by the die member 44. The faces 56 of the die member 44
_32 are sized and shaped to cooperate with the faces 32 of
33 the clinch nut bottom wall 26 as described in more detail
34 hereinbelow. The angle of the faces 56 of the die member
44 are also sized to cooperate with the bottom wall 26 of
36 the clinch nut 10. For example, when the bottom wall 26
37 of the clinch nut l0 is angled about 2o degrees relative
CA 02501754 1999-10-20
. 14
1 to a plane perpendicular to the central axis 20, the
2 faces 56 of the die member 44 are preferably angled about
3 18 to 22 degrees relative to a plane perpendicular to the
4 central axis 50.
~ FIGS. 6A to 6C illustrate installation of the clinch
6 nut 10 into a metal panel or plate 58 using the die
7 member 44, typically referred to as the "nut setting
8 process". The clinch nut 10 and the die member 44 are
9 coaxially positioned on opposite sides of the metal panel
58 at a position in which the clinch nut 1o is to be
' 11 secured to the metal panel 58 (best shown in FIG. 6A).
~12 The clinch nut 10 and the die member 44 are also
13 circumferentially oriented so that the inclined faces 32
14 of the clinch nut bottom wall 26 and the inclined faces
56 of the die member are circumferentially aligned.
16 The die Member 44 and the clinch nut 10 are
17 relatively moved toward one another in an axial direction
18 by any suitable manner such as a mechanical press or a
19 hydraulic or pneumatic plunger. It is noted that the
relative movement between the clinch nut l0 and the die
21 member 44 can be achieved by moving either one or both of
22 the components. The relative movement between the clinch
23 nut l0 and the die member 44 causes the shearing edges
24 40, 54 to cooperate to shear or punch an opening in the
metal~panel 58 (best shownwin FIG. 6B) into which the
26 punch portion 14 of the clinch nut 10 extends. The
27 resulting metal slug.60 is forced into the central
28 opening 52 in the die member 44.
29 The relative movement between the clinch nut 10 and
the die member 44 is continued until the lip 24 of'the
. 31 clinch nut 10 engages the metal panel 58 and the panel-
32 engaging end face 48 of the die member 44 forces metal
33 material of the metal panel 58 into the groove 22 of the
34 clinch nut 10. Metal material is coined between the
bearing surface of the clinch nut l0 and the bearing
36 surface of the die member 44. The coining action causes
37 material to flow into recesses in the~clinch nut. l0 which
CA 02501754 1999-10-20
- ~ 15
1 enhances retention of the clinch nut 10 to the metal
2 panel 58 to resist torsional load or push out~forces.
3 Material is forced into the undercut at the groove inner
4 wall 28 to improve pull-out strength and is forced into
5~ the corners formed by the polygonally-shaped groove walls
6 26, 28, 30 and the sides of the lugs 42 to improve torque
7 resistance.
8 While the width of the die end face 48 is radially
9 smaller than the width of the clinch nut groove 22 in the
illustrated embodiment, it is noted that the width of the
' il die end face 48 can be increased so that it extends
12 radially outward beyond the clinch nut 10. This is
13 particularly desirable when the metal panel 58 is a
14 softer material in order to limit~intrusion of the die 44
. 15 into the panel 58. It is also noted that when the metal
16 panel 58 is a softer material, the lip 24 of the clinch
17 nut 10 may intrude the metal panel 58 rather than just
18 engage it as shown in FIG. 6C.
19 Once the die member 44 is removed, the clinch nut 10
is securely fastened to the metal panel 58 (best shown in
21 FIG. 6C). The punch portion 14 of the clinch nut 10
22 extends into the opening formed in the metal panel 58 but
23 preferably does not extend beyond the other surface of
24 the metal panel 58. Installed in this manner, a threaded
fastener can be inserted in the threaded opening 16 of
26 the clinch nut 10 to secure a desired item to the metal
27 panel 58. It is noted that this procedure is to secure
28 the clinch nut l0 to thin metal panels 58, that is,
29 panels having a thickness of 3 mm or less. For metal
.30 panels having a thickness of .greater than 3 mm, the
31 aperture or opening is preferably pre-punched unless the
32 nut s punch portion 14 and body portion 12 are resized as
33 previously described. The remaining methodology for
34 installation is the same.
'FIGS. 7-9 illustrate a self-piercing clinch nut 70
36 according to a second embodiment of the present invention
37 wherein like reference number are utilized to indicate
CA 02501754 1999-10-20
16
1 like structure. The clinch nut 70 of the second
2 embodiment is substantially the same as the clinch nut 10
3 of the first embodiment described in detail hereinabove
4 except that the lugs 42 are of a different configuration.
The clinch nut 70 of the second embodiment illustrates
6 that the lugs 42 can have a different shape.
7 _ In the second embodiment, the lugs 42 are formed by
8 protuberances which axially extend above the groove
9 bottom wall 26 and radially extend across the groove 22
from the groove inner wall 28 to the groove outer wall
' 11 30. The upper sides of the lugs 42, which are the sides
12 opposite the bottom wall 26, are generally parallel with
13 the bottom wall 26 and angled or inclined relative to the
14 lip 24. .The outer ends of lug upper sides preferably
meet the inner edge of the lip 24 but alternatively can
16 be recessed below the lip 24. The lugs 42 are preferably
17 circumferentially spaced apart along the bottom wall 26
18 and preferably there is a lug 42 centrally located on
19 each face of the bottom wall 26. The cross-sectional
shape of the illustrated lugs 42 is rectangular. The
21 cross-sectional shape of the lugs 42, however, may be any
22 other suitable shape.
23 For example, an acceptable clinch nut 7o having a
24 thread size of M10x1.5 and for work pieces having a
minimum thickness of 0.050 inches (1.27 mm) can have a
26 bottom wall 26 with eight facets 32 inclined at an angle
27 of about 20°. The facets 32 are aligned with eight
28 facets 34 of the punch portion inner wall 28, eight
29 facets 36 of the. outer wall 30,. and eight faces 38 of the
body portion outer periphery. The outer wall 30 has a
31 height of about .005 inches to about .015 inches. The
32 body portion is about .712 to about .730 inches across
33 corners, is about .666 to about .674 inches across flats,
34 and has a height of about .314 to about .318 inches. The
distance between inner edges of the lip.24 is about .600
36 to about .606 inches. The punch portion 14 has a height
37 of about .043 to about .047 inches above the lip.24, a
CA 02501754 1999-10-20
17
1 diameter of about .514 to about .518 inches, and a base
2 diameter at the bottom wall of about .484 inches maximum.
3 The lugs 42 have a width of about .058 to about .081
4 inches.
~ FIGS. 10-12 illustrate a self-piercing clinch nut 80
6 according to a third embodiment of the present invention
7 wherein like reference numbers are utilized to indicate
8 like structure. The clinch nut 80 of the third
9 embodiment is substantially the same as the clinch nuts
10, 70 of the first and second embodiments described in
' 11 detail hereinabove except that the outer wall 30 of the
12 groove 22 is eliminated and the lugs 42 are of a
13 different configuration. The clinch nut 80 of the third
14 embodiment illustrates that the groove 22 can have a
different shape and further illustrates that the lugs 42
16 can have other shapes.
17 In the third embodiment, the groove 22 is formed by
18 only the bottom wall 26 and the inner wall 28. The
19 bottom and inner walls 26, 28 are preferably sized and
shaped the same as described in detail hereinabove with
.21 regard to the first embodiment except that the outer edge
22 of the bottom wall 26 extends to and meets the inner edge
23 of the lip 24. It is noted that the depth of the groove
24 22 is reduced when the outer wall 30 is eliminated and
all other dimensions remain the same.
. 26 In the third embodiment, the lugs 42 are formed by
27 protuberances which axially extend above the groove
~28 bottom wall 26 and radially extend across the groove 22
29 from the groove inner wall 28 to the lip 24. The upper
side of the lugs 42, which.is the side opposite the
31 bottom wall 26, is generally parallel with the bottom
32 wall 26 and angled or inclined relative to the lip 24.
33 The lugs 42 preferably have outer end surfaces 82 which
34 are parallel and co-planar with the lip 24 so that the
lugs 42 do not extend above the lip 24. Configured in
36 this.manner, the outer end surfaces 82 of the lugs 42
37 appear to be inwardly directed extensions of the~lip 24.
CA 02501754 1999-10-20
18
1 The outer ends of the lug lower sides meet the inner edge
2 of the lip 24 along the bottom wall 26. The lugs 42 are
3 preferably circumferentially spaced apart along the
4 bottom wall 26 and preferably there is a lug_42 centrally
located on each face 32 of the bottom wall 26. The
6 cross-sectional shape of the illustrated lugs 42 is
7 rectangular. The cross-sectional shape of the lugs 42,
8 however, may be any other suitable shape.
9 For example, an acceptable clinch nut 80 having a
l0 thread size of Mioxl.5 and for work pieces having a
' 11 minimum thickness. of 0.050 inches (1.27 mm) can have.a
12 bottom wall 26 with eight facets 32 inclined at an angle
13 of about 20°. The facets 32 are aligned with eight
14 facets 34 of the punch portion inner wall 28 and eight
faces 38 of the body portion outer periphery. The body
16~ portion is about .712 to about .730 inches across
17 corners, is about .666 to about'.674 inches across flats,
18 and has~a height of about .314 to about .318 inches. The
19 distance between inner edges of the lip 24 is about .600
to about .606 inches. The punch portion 14 has a height
21 of about .043 to about .047 inches above the lip 24, a
22 diameter of about .514 to about .518 inches, and a base
23 diameter at the bottom wall of about .484 inches maximum.
24 The lugs 42 have a width of about .058 to about .081
inches and a thickness of about .005 inches to .010.
26 inches.
27 FIGS. 13-15 illustrate a self-piercing clinch nut 90
28 according to a fourth embodiment of the present invention
29 wherein like reference numbers are utilized to indicate
like structure. The clinch nut 90 of the fourth W
31 embodiment is substantially the same as the clinch nut 80
32 of the third embodiment described in detail hereinabove
33 except that the lugs 42 are of a different configuration.
34 The clinch nut 90 of the fourth embodiment illustrates
that the lugs 42 can have a different location.
36 In the fourth embodiment, the lugs 42 are formed by
37 protuberances which axially extend above the lip 24
CA 02501754 1999-10-20
19
1 rather than the bottom wall 26 of the groove 22. The
2 upper sides of the lugs 42 are generally parallel with
3 the lip 24. The lugs 42 preferably have inner and outer
4 side surfaces 92, 94 and end surfaces 96 which are
perpendicular to the lip 24. The lugs 42 each extend
6 along the lip 24 and are spaced apart along the lip 24.
7 The lugs 42 preferably have a width generally equal to
8 the width of the lip 24. In the illustrated embodiment,
9 the lugs 42 are located adjacent alternating faces 32 of
the bottom wall 26 and the lugs 42 extend a distance
' 11 slightly longer than the width of each face 32 of the
12 bottom wall 26. The lug outer sides 94 extend the width
13 of a single face 32 of the bottom wall 26 and the~lug
14 inner sides 92 extend beyond the width of .a single face
32 of the bottom wall 26 to the outer edge of the lip 24.
16 It is noted that any other suitable quantity, shape, or
17 length of the lugs 42 can be alternatively utilized. The
18 cross-sectional shape of the illustrated lugs 42 is
19 rectangular. The cross-sectional shape of the lugs 42,
however, may be any other suitable shape. It is noted
21 that any other suitable quantity or length of lugs 42 can
22 be alternatively utilized. It is also noted that the
23 lugs 42 can protrude above the lip 24 in this manner when
24 the groove 22 has an outer wall 30 as described in detail
hereinabove with reference to the first and second .
26 embodiments.
27 For example, an acceptable clinch nut 90 having a
28 thread size of M10x1.5 and for work pieces having a
29 minimum thickness of 0.050 inches (1.27 mm) can have a
bottom wall 26 with eight facets 32 inclined at an~angle
31 of about 20°. The facets 32 are aligned with eight
32 facets 34 of the~punch portion inner wall 28, and eight
33 faces 38 of the body. portion outer periphery. The body
34 portion is about .712 to about .730 inches across
corners, is about .666 to about .674 inches across flats,
' 36 and-has a height of about .314 to about .318 inches. The
37 distance between inner edges of the lip 24 is about .600
CA 02501754 1999-10-20
1 to about .606 inches. The punch portion 14 has a height
2 of about .043 to about .047 inches above the lip 24, a
3 diameter of about .514 to about .518 inches, and a base
4 diameter at the bottom wall of about .484 inches maximum.
5 The lugs 42 have a height of about 0.05 mm to 0.20 mm.
6 FIGS. 16-18 illustrate a self-piercing clinch nut
7 100 according to a fifth embodiment of the present
8 invention wherein like references are used to indicate
9 like structure. The clinch nut 100 of the fifth
l0 embodiment is substantially the same as the clinch nuts
' 11 10, 70, 80, 90 of the first four embodiments described
12 hereinabove in detail except that the lip 24 and the lugs
13 42 are of a different configuration. The clinch nut 100
14 of the fifth embodiment further illustrates that the lugs
15 42 can have a different configuration and illustrates
16 that the lip 24 can have a different configuration.
17 In the fifth embodiment, the lip 24 has
18 interruptions so that it is formed by a plurality of
19 separate segments each associated with one of the faces
20 32 of the groove bottom wall 26. The separate segments
21. of the lip 24 include alternating narrow and wide
22 segments 102, 104. The narrow segments 102 generally
23 have a width as described and shown.with regard to the
24 first four embodiments. The wide segments 104, however,
have an increased width formed by extending the lip 24
26 further inward toward the inner wall 28 of the groove 22.
27 The interruptions are preferably grooves formed through
28 the lip 24 generally parallel to the length of the narrow
29 segments 102. The bottom surfaces 106 formed by.the
interruptions are preferably angled or inclined to~form
31 extensions of the adjacent bottom wall face associated
32 with the narrow segment 102.
33 The lugs 42 are formed by protuberances which
34 axially extend above the groove bottom wall 26 adjacent
the wide segments 104 of the lip 24. The lugs 42
36 radially extend across the groove 22 from the groove
3? inner wall 28 to the lip wide segments 104. The upper
CA 02501754 1999-10-20
21
1 side of the lugs 42, which is the side opposite the
2 bottom wall 26, is generally parallel with the bottom
3 wall 26 and inclined relative to the lip 24. The outer
4 ends of lug upper sides preferably meet the inner edge of
the lip wide segments 104 so that the lugs 42 do not
6 extend above the lip 24. The lugs 42 preferably have a
7 width which extends the full width of the associated face
8 32 of the bottom wall 26 such that none of the associated
9 face 32 of the bottom wall 26 is exposed.
For example, an acceptable clinch nut 100 having a
11 thread size of M10x1.5 and'for work pieces having a
12 minimum thickness of 0.050 inches (1.27 mm) can have a
13 bottom wall 26 with eight facets 32 inclined at an angle
14 of about 20°. The facets 32 are aligned with the facets
34 of the punch portion inner wall 28 and the faces ~38 of
16 the body portion outer periphery. The body portion is
17 about .712 to about .730 inches across corners, is about
~18 .666 to about .674 inches across flats, and has a height
19 of about .314 to about .318 inches. The distance between
inner edges of the narrow portions 102 of the lip 24 is
21 about .600 to about .606 inches. The distance between
22 inner edges of the wide portions 104 of the lip 24 is
23 about .537 to about .543 inches. The punch portion 14
24 has a height of about .043 to about .047 inches above the
lip 24, a diameter of about .514 to about .518 inches,
26 and a base diameter at the bottom wall of about .484
27 inches maximum.
28 FIGS. 19-21 illustrate a self-piercing clinch nut
29 110 according to a sixth embodiment of the present.
invention wherein like reference numbers are utilized to
31 indicate like structure. The clinch nut 110 of the sixth
32 embodiment is substantially the same as the clinch nut
33 100 of the fifth embodiment described hereinabove in
34 detail except that the lugs 42 are of a different
configuration. The clinch nut 110 of the sixth
36 embodiment further illustrates that the lugs 42 can have
37 different shapes.
CA 02501754 1999-10-20
22
1 The Iugs 42 are formed by protuberances which
2 axially extend above the groove bottom wall 26 adjacent
3 the wide segments 104 of the lip 24. The lugs 42
4 radially extend across the groove 22 from the groove
inner wall 28 to the wide segments 104 of the lip 24.
6 The upper side of the lugs 42, which is the side opposite
7 the bottom wall 26, is generally parallel with the upper
8 side of the lip 24 but is recessed below the lip 24. The
9 outer ends of the lugs 42 preferably extend less than the
full width of the lip wide segments 104 and have an
' 11 increasing width in an inward direction toward the inner
12 wall 28. The bottom surfaces 112 formed by the reduced
I3 size of the lugs 42 are preferably.angled or inclined to
14 form extensions of the adjacent bottom wall face
associated with the narrow segment 102.
16 For example, an acceptable clinch nut 110 having a
17 thread size of M10x1.5 and for work pieces having a
18 minimum~thickness of 0.050 inches (1.27 mm) can have a
19 bottom wall 26 with eight facets 32 inclined at an angle
of about 20°. The facets 32 are aligned with the facets
21 34 of the punch portion inner wall 28 and the faces 38 of
22 _ the body portion outer periphery. The body portion is
23 about .712 to about .730 inches across corners, is about
24 .666 to about .674 inches across flats, and has a height
of about .314 to about .318 inches. The distance between.
26 inner.edges of the narrow portions 102 of the Iip 24 is
27 about .600 to about .606 inches. The distance between
28 inner edges of the wide portions 104 of the lip 24 is
29 about .537 to about .543 inches. The punch portion 14
has.a height of about .043 to about .047~inches above the
31 lip 24, a diameter of about .514 to about .518 inches,
32 and a base diameter at the bottom wall of about .484
33 inches maximum.
34 FIGS. 22-24 illustrate a self-piercing clinch nut
120 according to a seventh embodiment of the present
36 invention wherein like reference numbers are utilized to
37 indicate like structure. The clinch nut 120 of the'
CA 02501754 1999-10-20
23
1 seventh embodiment is substantially the same as the
2 clinch nut 10 of the first embodiment described
3 hereinabove in detail except~that the walls 26 , 28, 30 of
4 the groove 22 are generally circular rather than faceted
and the lugs 42 are of a different configuration. The .
6 clinch nut 120 of the seventh embodiment further
7 illustrates that the groove walls 26, 28, 30 can have
8 other shapes and further that the lugs 42 can have
9 different shapes.
The groove bottom wall 26 is inclined as described
11 in detail hereinabove, but is now circular without the
12 above described facets. The bottom wall 26 of the
13 seventh embodiment is generally frusto-comically shaped.
14 The inner wall 28 is also inclined as described in detail
hereinabove, but is also now circular without the above
16 described facets. The inner wall 28 of the seventh
17 embodiment is generally frusto-comically shaped. The
18 groove.outer~wall 30 is circular or cylindrically-shaped.
19 It is noted that this circular shape of the groove 22 can
be utilized in each of the other embodiments.
21 The lugs 42 are formed by protuberances which
22 axially extend above the groove bottom wall 26 and
23 radially extend across the groove 22 from the groove
24 inner wall 28 to the inner wall. The inner ends of the
lugs also extend upward along the inner wall 26 or punch
26 portion 14. The lugs 42 are generally triangular in
27 cross-section forming a central top edge and have
28 decreasing widths in the inward. direction to form points
29 or tips at the inner ends of the lugs 42.
FIGS. lA, 2 and 3A, illustrate a variation of the
31 clinch nut 10 of the first embodiment shown in FIGS 1-3,
32 wherein like reference numbers are utilized to indicate
33 like structure. The clinch nut is substantially the same
34 as the clinch nut 10 of the first embodiment described
hereinabove in detail except that the lugs 42 extend
36 upward along the facets 34 of the punch portion 14 above
37 the lip 24. This variation of the clinch nut 10 further
CA 02501754 1999-10-20
24
1 illustrates that the lugs 42 can upwardly extend along
2 the inner wall 28.
3 The upwardly extending portion of each lug 42
4 preferably has an outer side which is substantially
parallel with the central axis 20 and, in the first
6 embodiment, substantially perpendicular to the upper
7 sides of the horizontally extending portion of the lugs
8 42. The upwardly extending portion, therefore, generally
9 removes the undercut of the punch portion 14 at the lugs
42.
11 For example, the above-described specific example of
12 the first embodiment can additionally have an upwardly
13 extending portion which extends above the lip 24 about
14 .041 inches. It is noted that while this variation is
specifically shown with regard to the clinch nut'
16 according to the first embodiment of the present
17 invention, it similarly applies to the other embodiments
18 having the lugs 42 within the groove and is particularly
19 advantageous with the second embodiment (FIGS. 7-9) and
the third embodiment (FIGS. 10-12).
21 Although particular embodiments of the invention
22 have been described in detail, it will be understood that
23 ,the invention is not limited correspondingly in scope,
24 but includes all changes and modifications coming within
the spirit and terms of the claims appended hereto.
