Title of Invention

A FASTENER ASSEMBLY JOINING TWO METAL SHEETS WITH FLUSH END SURFACES

Abstract A double flush clinch stud includes adjacent clinch means of different diameter with planner end surfaces. The stud may be employed in forming an assembly wherein two metal sheets are joined in face-to-face contacting relationship. This assembly can provide a flush attachment on the outside surfaces of both the sheets when the length of the stud is equal to the combined width of the sheets. In an alternative embodiment, the top undercut groove can be adapted to be underfilled with the material of the top sheet. In this alternate configuration, the top sheet is effectively constrained between the head of the fastener and the second sheet while permitting the top sheet to pivot with respect to the second sheet.
Full Text DOUBLE FLUSH CLINCH STUD
RELATED APPLICATIONS
The present application is related to provisional patent application serial
number 60/620,345 entitled "Double Flush Clinch Stud" filed on October 21, 2004,
priority from which is hereby claimed.
FIELD OF THE INVENTION
The present invention relates to fasteners for securing two sheets of metal
face-to-face. It further relates to fasteners that provide a flush attachment to the
sheets by deformation of the sheet material.
BACKGROUND OF THE INVENTION AND PRIOR ART
Most commonly, metal sheets are fastened together using rivets or spot
welds. These methods of fastening, however, have their drawbacks inasmuch as
the spot welds leave a weld scale and burn the surface of the sheets. Spot welding
is also not effective in sheet materials which are not easily welded, such as is the
case with very thin or dissimilar materials. Furthermore, the burned sheets may
leave an unacceptable aesthetic appearance. Rivets can perform a similar function
but they do not leave a finish flush with the surface of the sheets which may be a
requirement in some applications. As yet another alternative, adhesives or other
bonding agents such as epoxies can be used, however these are often very messy
and very costly. Additional methods such as Tog-L-LocĀ® which forms sheets
together and Henrob style fasteners deform the sheets being attached. Allowing
for rotation is also possible. Of the technologies discussed above, the additional
feature of rotation can only be accomplished by a rivet which does not install flush.

U.S. Patent 3,242,962 to Dupree discloses a double-sided clinch type insert
which installs between the sheets being joined. However, there are many problems
and disadvantages of the Dupree fastener. For example, it allows for installation of
only one fastener, due to the fact that once the sheets are joined nothing additional
can be inserted between them. This also negates the advantage of autofeeding and
installing the Dupree fastener using more efficient, modern techniques. In addition,
the Dupree fastener must be the same thickness as the width of the combined
sheets. And finally, while the Dupree fastener may be modified to permit rotation
by removing a knurl in one of the undercuts, the rotating clinch would significantly
weaken and fail after numerous cycles.
There is therefore a need in the art for means for securing two metal sheets
together which provides flush finish on both metal sheets, with the additional
feature of providing a pivot for rotation, and avoids the weld scale or epoxy mess
of the aforementioned fastening methods.
SUMMARY OF THE INVENTION
The present invention provides an extremely simple solution to the above-
stated need in the art for a fastening method which secures two metal sheets face-
to-face. The device is a clinching stud having adjacent fastening means of differing
diameter so that the stud may be pressed into suitably dimensioned holes of aligned
sheets in a single pressing operation. As will be more fully described herein,
double flush attachment is provided without the need for the heat of welding or the
mess and expense of bonding adhesives, or deformation of the surface of the sheets
being bonded.
More specifically, the applicant has devised a clinch-type fastener for

joining parallel sheets having aligned apertures comprising a shank having a head at
one end and an endcap at the opposite end, the head being a first displacer, a top
surface, and being of the largest diameter of the fastener. A first undercut groove
on the shank is located immediately below the first displacer having a first diameter
and a second displacer on the shank located immediately below the first undercut
groove having a second diameter less than the first diameter. A second undercut
groove on the shank is located immediately below the second displacer, and the
endcap is located immediately below the undercut groove and is of lesser diameter
than the second displacer. The fastener preferably includes opposing planar
circular top and bottom surfaces.
The inventive fastener is advantageously employed in forming an assembly
wherein two metal sheets are joined in face-to-face contacting relationship, the first
sheet having a first hole therein including sidewalls which occupy substantially all
of the first undercut groove of the fastener and wherein the second planar sheet is
joined in face-to-face relationship with the first sheet. The second sheet has a
second hole therein of lesser diameter than the first hole in the first sheet and is
concentric therewith. The second hole is of lesser diameter than the first hole and
includes sidewalls which occupy substantially all of the second undercut groove of
the fastener. This assembly provides flush attachment with a top surface of the
first sheet being coplanar with a top surface of the head of the fastener and the
endface of the endcap of the fastener being flush or sub-flush with the bottom
surface of the second sheet. This results in an assembly whereby the top undercut
groove can alternatively be underfilled with the material of the top sheet
respectively, while maintaining a high pushout strength. With this alternative, the

top sheet is effectively constrained between the head of the fastener and the second
sheet while permitting a strong pivot joint. Pushout performance remains high due
to the larger diameter, and hence, displaced volume, of the top displacer and
undercut.
Compared with some of the prior art described above such as the Dupree
fastener, the present invention provides the advantage of installing from the top of
the sheets and therefore can be installed in any pattern on multiple fasteners as
desired. Additionally, the present invention only requires a minimum thickness of
the second sheet and the second sheet can be thicker than the lower shank of the
fastener if the fastener is installed blind in the second sheet. Also, according to the
invention as will be more fully described below, the top sheet is contained between
the head of the fastener and the second sheet. This permits the top sheet to rotate
freely by underfilling the undercut while maintaining a high push-out force and
flush installation.
From the following drawings and description of the preferred embodiment,
it will be appreciated by those of skill in the art that the objects of the invention
have been achieved. While the present invention will be described with the
reference to a specific embodiment, the following description is illustrative of the
invention and is not to be construed as limiting the invention. Various
modifications to the present invention can be made to the preferred embodiment by
those skilled in the art without departing from the true spirit and scope of the
invention. It will be noted here that for better understanding like components are
designated by the reference numerals throughout the various figures of drawing
which follow.

DESCRIPTION OF THE DRAWINGS
Figure 1 is a side view of the clinch stud of the invention with the displacers
and undercuts indicated.
Figure 2 is a right front top exploded assembly view of the clinch connector
in alignment with the receiving apertures of two sheets to be fastened.
Figure 3 is a partial side sectional view of the installation of the invention
by pressing.
Figure 4 is a side sectional view showing the resulting completed
installation of the invention.
Figure 5 is a side sectional view of an alternate embodiment of the
invention in which the clinch stud is installed into a blind hole in the second sheet.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to Figure 1, the present invention is a clinch-type fastener
which has two pairs of displacers 13 and 15 and related undercuts 14 and 16
coaxially adjacent one another, the first pair 13 and 14 being larger in diameter
than the other pair. The fastener is terminated at the bottom by endcap 17. These
structures lie along a shank of the fastener between a top surface 18 and a bottom
surface 19 of endcap 17.
As shown in Figure 2, two sheets 1 and 2 are held in alignment with the
clinch connector of the invention being forcibly applied from above. Sheets 1 and
2 are shown separated in this figure for illustration only. The top sheet and second
sheet include aligned holes 3 and 4 of different diameter which correspond to the
diameters of the respective displacers and undercuts of the connector. The
diameter of hole 3 in the top sheet is greater than the diameter of hole 4 in the

second sheet, allowing the first advancing clinching feature of the connector to
pass through it.
As depicted in Figure 3, an installation force is applied to punch 21 which
forces the clinch connector of the invention 11 into sheets 1 and 2 against
installation anvil 23. The arrow shows the direction of application of ferce to the
clinch connector which is applied to the first and second sheets. The connector 11
is applied by a single application of force during a pressing operation against anvil
23 which achieves the resulting installation as shown in Figure 4 wherein the top
displacer and undercut clinch into the top of the two sheets 1 being bonded and the
lower displacer and undercut simultaneously clinch into the second sheet 2.
Referring now to Figure 4, after the pressing operation is complete, the
sheets become locked together by the cold flow of metal by the top head/displacer
13 forcing the cold flow of metal 25 of the top sheet into the top undercut and
similarly the cold flow of metal 26 is displaced by displacer 15 into the bottom
undercut within the second sheet locking the clinch stud of the invention into both
sheets, thus joining them together. As depicted in Figure 5, the second sheet 2 can
have a blind hole. As a significant advantage of the invention, if the first and or
second undercut grooves are of sufficient diameter such that they are underfilled by
the material of their respective sheets, the present invention provides a locking
pivot whereby the sheets may be attached flush in a controlled manner while
providing for relative rotation between the sheets.
It should be understood that there may be other modifications and changes
to the present invention that will be obvious to those of skill in the art from the
foregoing description, however, the present invention should be limited only by the

following claims and their legal equivalents.

We Claim:
1. An assembly, comprising:
a fastener joining two metal sheets in face-to-face contacting relationship,
comprising,
a shank having a preformed head at one end and a preformed endcap at the
opposite end;
the head being a first displacer having a top surface and being the largest
diameter of said fastener;
a first undercut groove on said shank, located immediately below said first
displacer, said first undercut groove having a first diameter;
a second displacer on said shank, located immediately below said first
undercut groove, said second displacer having a second diameter less than
said head largest diameter and larger than said first diameter;
a second undercut groove on said shank located immediately below said
second displacer; and
the endcap located immediately below said second undercut groove and being
of lesser diameter than said second displacer's second diameter;
a first planar sheet having a first hole therein including sidewalls which
occupy substantially all of said first undercut groove of said fastener; and
a second planar sheet joined in face-to-face relation to said first sheet, said
second sheet having a second hole therein of lesser diameter than said first
hole in said first sheet and being concentric therewith, said second hole being
of lesser diameter than said first hole and having sidewalls which occupy
substantially all of said second undercut groove of said fastener, said top
surface of said fastener is substantially flush with a top surface of said first

sheet and an endface of said endcap of said fastener is substantially flush
with a bottom surface of said second sheet.
2. The assembly of claim 1 wherein said first and second holes are circular.
3. The assembly of claim 1 wherein the second hole is a blind hole in the second
sheet.
4. The assembly of claim 1 wherein the first undercut groove of said fastener is
of sufficient diameter such that it is underfilled by the material of the first
sheet thereby providing relative rotary motion between said fastener and said
sheet.
5. The assembly of claim 1 wherein both said first and second undercut grooves
are of sufficient diameter such that they are underfilled with the material of
said first and second sheets respectively.
6. The assembly of claim 1 wherein the fastener top surface and the fastener
endface are opposing planar top and bottom surfaces.
7. The assembly of claim 1 wherein the fastener top surface and the fastener
endface are circular surfaces.


A double flush clinch stud includes adjacent clinch means of different diameter with
planner end surfaces. The stud may be employed in forming an assembly wherein
two metal sheets are joined in face-to-face contacting relationship. This assembly
can provide a flush attachment on the outside surfaces of both the sheets when the
length of the stud is equal to the combined width of the sheets. In an alternative
embodiment, the top undercut groove can be adapted to be underfilled with the
material of the top sheet. In this alternate configuration, the top sheet is effectively
constrained between the head of the fastener and the second sheet while permitting
the top sheet to pivot with respect to the second sheet.

Documents:

01290-kolnp-2007-abstract.pdf

01290-kolnp-2007-claims.pdf

01290-kolnp-2007-correspondence others 1.1.pdf

01290-kolnp-2007-correspondence others 1.2.pdf

01290-kolnp-2007-correspondence others 1.3.pdf

01290-kolnp-2007-correspondence others.pdf

01290-kolnp-2007-description complete.pdf

01290-kolnp-2007-drawings.pdf

01290-kolnp-2007-form 1.pdf

01290-kolnp-2007-form 18.pdf

01290-kolnp-2007-form 2.pdf

01290-kolnp-2007-form 3.pdf

01290-kolnp-2007-form 5.pdf

01290-kolnp-2007-international publication.pdf

01290-kolnp-2007-pct request.pdf

01290-kolnp-2007-priority document.pdf

1290-KOLNP-2007-(22-11-2011)-CORRESPONDENCE.pdf

1290-KOLNP-2007-ABSTRACT 1.1.pdf

1290-KOLNP-2007-AMANDED CLAIMS.pdf

1290-KOLNP-2007-CORRESPONDENCE.pdf

1290-kolnp-2007-correspondence1.1.pdf

1290-KOLNP-2007-DESCRIPTION (COMPLETE) 1.1.pdf

1290-KOLNP-2007-DRAWINGS 1.1.pdf

1290-KOLNP-2007-EXAMINATION REPORT REPLY RECIEVED 1.1.pdf

1290-kolnp-2007-examination report.pdf

1290-KOLNP-2007-FORM 1-1.1.pdf

1290-KOLNP-2007-FORM 1-1.2.pdf

1290-kolnp-2007-form 13.1.pdf

1290-KOLNP-2007-FORM 13.pdf

1290-kolnp-2007-form 18.pdf

1290-KOLNP-2007-FORM 2-1.1.pdf

1290-kolnp-2007-form 26.pdf

1290-KOLNP-2007-FORM 3-1.1.pdf

1290-kolnp-2007-form 3.pdf

1290-KOLNP-2007-FORM 5-1.1.pdf

1290-kolnp-2007-form 5.pdf

1290-KOLNP-2007-FORM-27-1.pdf

1290-KOLNP-2007-FORM-27.pdf

1290-KOLNP-2007-GPA.pdf

1290-kolnp-2007-gpa1.1.pdf

1290-kolnp-2007-granted-abstract.pdf

1290-kolnp-2007-granted-claims.pdf

1290-kolnp-2007-granted-description (complete).pdf

1290-kolnp-2007-granted-drawings.pdf

1290-kolnp-2007-granted-form 1.pdf

1290-kolnp-2007-granted-form 2.pdf

1290-kolnp-2007-granted-specification.pdf

1290-KOLNP-2007-OTHERS.pdf

1290-kolnp-2007-others1.1.pdf

1290-KOLNP-2007-PETITION UNDER RULE 137.pdf

1290-KOLNP-2007-REPLY TO EXAMINATION REPORT.pdf

1290-kolnp-2007-reply to examination report1.1.pdf

abstract-01290-kolnp-2007.jpg

CORRESPONDENCE OTHERS 1.4.pdf

TRANSLATED COPY OF PRIORITY DOCUMENT 1.1.pdf


Patent Number 248342
Indian Patent Application Number 1290/KOLNP/2007
PG Journal Number 27/2011
Publication Date 08-Jul-2011
Grant Date 05-Jul-2011
Date of Filing 12-Apr-2007
Name of Patentee PEM MANAGEMENT, INC
Applicant Address 300 DELAWARE AVENUE, SUITE 1225, WILMINGTON, DE
Inventors:
# Inventor's Name Inventor's Address
1 MICHAEL J. MALONEY 5480 SILO HILL ROAD, DOYLESTOWN, PA 18901
PCT International Classification Number F16B 19/04
PCT International Application Number PCT/US2005/036366
PCT International Filing date 2005-10-12
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 60/620,345 2004-10-21 U.S.A.
2 11/163,138 2005-10-06 U.S.A.