U.S. patent application number 09/130428 was filed with the patent office on 2001-11-29 for zero looseness fastener for linkage assembly.
Invention is credited to OLSSON, NILS O., WILLMS, DAVID C..
Application Number | 20010046411 09/130428 |
Document ID | / |
Family ID | 22444648 |
Filed Date | 2001-11-29 |
United States Patent
Application |
20010046411 |
Kind Code |
A1 |
OLSSON, NILS O. ; et
al. |
November 29, 2001 |
ZERO LOOSENESS FASTENER FOR LINKAGE ASSEMBLY
Abstract
A fastener is used to connect a first link to a second link in a
vehicle seat assembly. The fastener has a head portion and a body
portion extending outwardly from the head portion and defining an
external diameter. The body portion is generally cylindrical and
has a central bore with an internal diameter that is less than the
external diameter. The method for connecting the first link to the
second link with the fastener includes the steps of inserting the
central body portion through aligned apertures in the links to form
a subassembly and holding the subassembly fixed while a tooling
member applies a linear load to the distal end of the body portion.
The tooling member is inserted into the central bore and deforms
the body portion for engagement with the first and second links to
allow relative rotational movement between the links while
eliminating relative linear movement therebetween.
Inventors: |
OLSSON, NILS O.; (GLEN ELYN,
IL) ; WILLMS, DAVID C.; (GEORGETOWN, CA) |
Correspondence
Address: |
ROBERT K.ROTH ESQ.
DURA AUTOMOTIVE SYSTEMS INC.
2791 RESEARCH DRIVE
ROCHESTER HILLS
MI
48309-3575
US
|
Family ID: |
22444648 |
Appl. No.: |
09/130428 |
Filed: |
August 6, 1998 |
Current U.S.
Class: |
403/281 |
Current CPC
Class: |
F16C 11/04 20130101;
B60N 2/161 20130101; Y10T 403/75 20150115; B60N 2/1803 20130101;
Y10T 403/4958 20150115 |
Class at
Publication: |
403/281 |
International
Class: |
F16B 001/00; B25G
003/28; F16G 011/00 |
Claims
We claim:
1. A method for connecting a first link to a second link comprising
the steps of (1) providing a fastener having a head portion and a
cylindrical body portion extending therefrom and terminating at a
distal end, a first link having a first external surface, a first
internal surface, and a first aperture extending therebetween, and
a second link having a second external surface, a second internal
surface, and a second aperture extending therebetween; (2) aligning
the first aperture with the second aperture; (3) inserting the body
portion of the fastener into the first and second apertures; and
(4) deforming the body portion into engagement with the first and
second links to allow relative rotational movement between the
links while eliminating free play.
2. A method as recited in claim 1 including the step of applying a
longitudinal load to the distal end of the body portion to cause
plastic deformation.
3. A method as recited in claim 1 including the steps of providing
the first link with a first thickness, the second link with a
second thickness, and the body portion with a length that is
greater than the sum of the first and second thicknesses prior to
step (2); holding the first internal face of the first link against
the second internal face of the second link during step (2); and
inserting the body portion of the fastener through the first and
second apertures such that the head portion engages the first
external face of the first link while a segment of the body portion
extends beyond the second external face of the second link during
step (3).
4. A method as recited in claim 3 including the steps of applying
the longitudinal load to the distal end of the body portion and
causing the segment of the body portion that extends beyond the
second link to bend transversely with respect to the longitudinal
load to form a lip that partially engages the second external face
of the second link during step (4).
5. A method as recited in claim 4 including the step of locking the
second link to the fastener via the lip so that there is no
relative rotational movement between the second link and the
fastener while allowing the first link to move freely.
6. A method as recited in claim 1 including the steps of creating a
subassembly comprised of the first link, the second link, and the
fastener during step (3); holding the subassembly fixed prior to
step (4); and moving a tooling member along a linear path toward
the subassembly for engagement with the body portion to apply the
longitudinal load.
7. A method as recited in claim 6 including the steps of providing
the body portion with a central bore having a bore diameter and
providing the tooling member with a extension having a diameter
less than the bore diameter and having a curved exterior surface
surrounding the extension; inserting the extension into the bore
such that the curved exterior surface engages the distal end of the
body portion; and deforming the distal end of the body portion by
pressing the extension further into the bore causing the distal end
to bend outwardly along the curved exterior surface of the tooling
member to form a lip.
8. A method as recited in claim 1 including the steps of providing
the body portion with a generally uniform external diameter and a
bore with a generally uniform bore diameter that is less than the
external diameter; and applying a longitudinal load to the body
portion to increase the external and internal diameters, causing
the body portion to engage the first and second links to hold the
fastener firmly in place.
9. A fastener for connecting a first member to a second member
comprising: a head portion; and a body portion extending outwardly
from said head portion and defining an external diameter, said body
portion being generally cylindrical and having a central bore with
an internal diameter that is less than the external diameter
wherein said body portion is deformable for engagement with the
first and second members to allow relative rotational movement
between the members while eliminating relative linear movement
therebetween.
10. A fastener as recited in claim 9 wherein said body portion is
perpendicular to said head portion.
11. A fastener as recited in claim 9 wherein said head portion is
circular.
12. A fastener as recited in claim 9 wherein said body portion
terminates at a distal end, said distal end for receiving a
longitudinal load for plastically deforming said body portion.
13. A fastener as recited in claim 12 wherein said longitudinal
load causes said internal and external diameters to increase
resulting in the body portion engaging the first and second members
to hold the fastener firmly in place.
14. A fastener as recited in claim 12 wherein said distal end bends
transversely to said longitudinal load and forms a lip for engaging
one of the members.
15. A fastener as recited in claim 14 wherein said lip locks the
fastener to one of the members via said lip to prevent relative
rotational movement between the one member and the fastener while
allowing the other member to move freely.
16. A vehicle linkage assembly comprising: a first link having a
first external surface, a first internal surface, and a first
aperture extending therebetween; a second link having a second
external surface, a second internal surface, and a second aperture
extending therebetween; a fastener having a head portion and a
cylindrical body portion extending therefrom and terminating at a
distal end wherein said body portion is inserted through said first
and second apertures and plastically deformed to engage said first
and second links to hold said fastener in place; and said first and
second links being movable to cause a seat to move.
17. An assembly as recited in claim 16 wherein said distal end of
said body portion receives a linear load causing said body portion
to plastically deform resulting in relative rotational movement
between said first and second links while eliminating relative
linear movement between said first and second links.
18. An assembly as recited in claim 17 wherein said first link has
a first thickness, said second link has a second thickness, and
said body portion has a length that is greater than the sum of the
first and second thicknesses such that when said internal face of
said first link is placed against said internal face of said second
link and said body portion is inserted through said first and
second links, a segment of said body portion extends beyond said
links.
19. An assembly as recited in claim 18 wherein the linear load is
applied to the distal end of the body portion causing said segment
of said body portion to bend transversely with respect to the
linear load, forming a lip for engaging the external surface of the
second link.
20. An assembly as recited in claim 19 wherein said second link is
locked to said fastener via said lip to prevent relative rotational
movement between said second link and said fastener while allowing
said first link to move freely.
Description
BACKGROUND OF THE INVENTION
[0001] This application relates to a fastener used for connecting a
first link member to a second link member and more particularly to
a fastener having a body portion that is deformed to engage the
members in order to eliminate free play while still allowing
relative rotational movement.
[0002] Linkage assemblies are often used in seat assemblies to
provide various functions including seat adjustment capability.
Linkage assemblies typically include two or more link members,
which are joined to each other by using various methods. The link
members typically receive input from an adjuster control member
which causes the links to rotate relative to one another to achieve
a desired position. In known links, as the links rotate,4 there has
typically been free play or linear movement between the links. This
free play is detrimental to the stability of the adjuster.
[0003] Various methods have been used to eliminate the free play
between link members. Often bushings or bushing materials are used
in the link assembly to take up the free play yet permit the links
to rotate relative to one another. This is expensive and requires
additional assembly time and materials.
[0004] Thus, it is desirable to eliminate the use of bushings and
bushing type materials from linkage assemblies by providing a
linkage assembly that uses a fastener which allows relative
rotational movement between link members but eliminates free play
between the members. By eliminating the use of bushings, the cost
of the linkage assembly is reduced and assembly time is
decreased.
SUMMARY OF THE INVENTION
[0005] In a disclosed embodiment, a fastener used to connect a
first member to a second member includes a head portion and a body
portion. Preferably, the first and second members are links in a
seat adjuster assembly. The body portion extends outwardly from the
head portion and defines an external diameter. The body portion is
generally cylindrical and has a central bore with an internal
diameter that is less than the external diameter. The body portion
is deformable for engagement with the first and second members to
allow relative rotational movement between the members while
eliminating relative linear movement therebetween.
[0006] The preferred inventive method for connecting a first member
to a second member includes providing a fastener having a head
portion and a cylindrical body portion extending therefrom and
terminating at a distal end, a first member having a first
aperture, and a second member having a second aperture. The first
aperture is aligned with the second aperture, the body portion of
the fastener is inserted into the first and second apertures, and
the body portion is deformed into engagement with the first and
second members to allow relative rotational movement between the
members while eliminating relative linear movement between the
members.
[0007] Deforming the body portion of the fastener eliminates
undesirable free play between the two members while still allowing
the members to rotate with respect to each other. The fastener
eliminates the use of expensive bushings and is easily installed,
easily maintained, and is inexpensive. These and other features can
be understood from the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a perspective view of seat track assembly with a
linkage subassembly using the subject fastener;
[0009] FIG. 2 is a top view of a linkage assembly with the subject
fastener; and
[0010] FIG. 3 is a cross sectional view of the linkage assembly of
FIG. 2 shown with a tooling member.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] A vehicle seat mounting assembly is shown generally at 10 in
FIG. 1. The seat mounting assembly 10 includes a lower track 12
that is mounted to a vehicle floor 14 and an upper track 16 that
slides with respect to the lower track 12 for seat adjustment in a
forward or rearward position. The seat mounting assembly 10 also
includes adjustment capability for adjusting the seat vertically.
The vertical adjuster assembly is shown generally at 18 and
includes a linkage assembly 20 which allows the seat to be raised
or lowered to accommodate occupants of varying heights.
[0012] The linkage assembly 20 is shown in more detail in FIG. 2. A
first link member 22 is connected to a second link member 24 with a
fastener 26. A typical linkage assembly 20 includes a least two
link members 22, 24, however, a greater number of link members can
be used with the subject fastener. Only two link members 22, 24 are
shown for simplicity. The fastener 26 used to connect the links 22,
24 allows the links to rotate relative to one another.
[0013] A cross-sectional view of the inventive fastener 26 is shown
in FIG. 3. The fastener is preferably made from a low carbon steel
such as SAE 1010, however, aluminum, zinc or other materials well
known in the art could be used. The fastener 26 includes a head
portion 28 and a body portion 30 extending outwardly from the head
portion 28 and defining an external diameter D1. The head portion
28 is preferably circular, however, other shaped heads could be
used. The body portion 30 is cylindrical and has a central bore 32
with an internal diameter D2 that is less than the external
diameter D1. The body portion 30 is preferably perpendicular to the
head portion 28. The body portion 30 is deformable for engagement
with the first 22 and second 24 link members to allow relative
rotational movement between the members 22, 24 while eliminating
undesirable relative linear movement or free-play between the
members 22, 24.
[0014] The body portion 30 terminates at a distal end 34, which
receives a longitudinal load for deforming the body portion 30. The
longitudinal load is preferably applied linearly to the distal end
34 of the body portion 30. The longitudinal load causes the
internal D2 and external D1 diameters to increase resulting in the
body portion 30 expanding outwardly to engage the first 22 and
second 24 members to hold the fastener 26 firmly in place. The body
portion 30 is preferably plastically deformed such that the shape
and/or size of the body portion 30 is permanently changed due to
the sustained application of the load beyond the elastic limit of
the material.
[0015] The fastener 26 is shown in FIG. 3 before and after
deformation. The post deformation fastener 26 is shown with the
cross-hatched lines. As the load is applied to the distal end 34 of
the body portion 30, the distal end 34 bends transversely to the
longitudinal load and forms a lip 36 for engaging one of the
members. The lip 36 locks the fastener 26 to one of the members to
prevent relative rotational movement between the one member and the
fastener 26 while allowing the other member to move freely. Thus,
the fastener 26 holds the link members 22, 24 together and allows
relative rotational movement between the members 22, 24, but is
fixed to one of the two (2) link members to prevent rotation
between that link member and the fastener 26. This will be
discussed in greater detail below.
[0016] The first link 22 has a first external surface 38, a first
internal surface 40, and a first aperture 42 extending between the
external 38 and internal 40 surfaces. The second link has a second
external surface 44, a second internal surface 46, and a second
aperture 48 extending between the external 44 and internal 46
surfaces. The body portion 30 is first inserted through the first
42 and second 48 apertures and then is plastically deformed to
engage the first 22 and second 24 links to hold the fastener 26 in
place.
[0017] The first link has a first thickness T1, the second link has
a second thickness T2, and the body portion 30 has a length L that
is greater than the sum of the first T1 and second T2 thicknesses
such that when the internal face 40 of the first link 22 is placed
against the internal face 46 of the second link 24 and the body
portion 30 is inserted through the first 22 and second 24 links, a
segment 50 of the body portion 30 extends beyond the links 22, 24
as assembled. The linear load that is applied to the distal end 34
of the body portion 30 causes the segment 50 of the body portion 30
to bend transversely with respect to the linear load. This forms
the lip 36 for engaging the external surface 44 of the second link.
The second link 24 is locked to the fastener 26 via the lip 36 to
prevent relative rotational movement between the second link 24 and
the fastener 26 while allowing the first link 22 to move
freely.
[0018] The method for connecting the first link 22 to the second
link 24 includes the steps of aligning the first aperture 42 with
the second aperture 48, inserting the body portion 30 of the
fastener 26 into the first 42 and second 48 apertures, and
deforming the body portion 30 into engagement with the first 22 and
second 24 links to allow relative rotational movement between the
links 22, 24 while eliminating free play. The step of deforming the
body portion 30 includes applying a longitudinal load to the distal
end 34 of the body portion 30 to cause the deformation.
[0019] Additional steps include holding the internal face 40 of the
first link 22 against the internal face 46 of the second link 24
and inserting the body portion 30 of the fastener 26 through the
first 42 and second 48 apertures such that the head portion 28
engages the external face 38 of the first link while the segment 50
of the body portion 30 extends beyond the external face 44 of the
second link 24. The longitudinal load is applied to the distal end
34 of the body portion 30 and the segment 50 of the body portion 30
bends transversely with respect to the longitudinal load to form
the lip 36 that partially engages the external face 44 of the
second link 24. As the lip 36 is bent under the load, the second
link 24 is locked to the fastener 26 so that there is no relative
rotational movement between the second link 24 and the fastener 26
while allowing the first link 22 to move freely.
[0020] A tooling member 52 is used to provide the load that deforms
the body portion 30 of the fastener 28. First, a subassembly
comprised of the first link 22, the second link 24, and the
fastener 26 is created. The subassembly is held fixed and the
tooling member 52 is moved along a linear path toward the
subassembly to engage the body portion 30 for deformation.
[0021] The tooling member 52 has a extension 54 with a diameter
that is less than the internal bore diameter D2 and which has a
curved exterior surface 56 surrounding the extension 54. The
tooling member 52 applies the longitudinal load as the extension 54
is inserted into the bore 32 such that the curved exterior surface
56 engages the distal end 34 of the body portion 30, causing the
body portion 30 to swell or expand outwardly. The distal end 34 of
the body portion 30 is deformed by pressing the extension 54
further into the bore 32 causing the distal end 34 to bend
outwardly along the curved exterior surface 56 of the tooling
member 52 to form the lip 36. Thus, once the body portion 30 has
expanded with the apertures 42, 48 to its maximum limit, the
segment 50 of material is bent transversely to the load applied by
the tooling member 52 to form the lip 36.
[0022] The use of the subject fastener in a linkage assembly 20
provides relative rotational movement between link members 22, 24
while eliminating undesirable free play or relative linear movement
between the members 22, 24. This eliminates the need for expensive
bushings or bushing type materials, thus reducing cost and assembly
time.
[0023] Preferred embodiments of this invention have been disclosed,
however, a worker of ordinary skill in the art would recognize that
certain modifications would come within the scope of this
invention. For that reason the following claims should be studied
to determine the true scope and content of this invention.
* * * * *