U.S. patent application number 11/849731 was filed with the patent office on 2009-03-05 for lightweight heavy duty bushing with easy assembly.
Invention is credited to Michael Brannigan, Ashley Thomas Dudding, Christopher Wayne Forrest, Richard Gregory Vogler.
Application Number | 20090060640 11/849731 |
Document ID | / |
Family ID | 40407791 |
Filed Date | 2009-03-05 |
United States Patent
Application |
20090060640 |
Kind Code |
A1 |
Vogler; Richard Gregory ; et
al. |
March 5, 2009 |
LIGHTWEIGHT HEAVY DUTY BUSHING WITH EASY ASSEMBLY
Abstract
A lightweight heavy duty bushing assembly for use in a vehicle
suspension system and being low cost and having a high assembly
tolerance is disclosed. A metal bar pin is press fit into a bushing
formed from a metal sleeve bonded to an elastomeric housing. The
metal sleeve is deformable such that exact tolerances of the metal
sleeve and the bar pin are not required. The metal bar pin has
extended ends with a hole in each end for attachment of the metal
bar pin to vehicle suspension components, mounting brackets, or to
the vehicle frame.
Inventors: |
Vogler; Richard Gregory;
(Naperville, IL) ; Brannigan; Michael; (Narbeth,
PA) ; Dudding; Ashley Thomas; (Yorkville, IL)
; Forrest; Christopher Wayne; (Auburn, IN) |
Correspondence
Address: |
COOK ALEX LTD
SUITE 2850, 200 WEST ADAMS STREET
CHICAGO
IL
60606
US
|
Family ID: |
40407791 |
Appl. No.: |
11/849731 |
Filed: |
September 4, 2007 |
Current U.S.
Class: |
403/135 ;
403/225 |
Current CPC
Class: |
F16F 1/3863 20130101;
Y10T 403/32737 20150115; F16F 1/3842 20130101; Y10T 403/455
20150115; Y10T 403/4966 20150115; Y10T 403/4949 20150115; Y10T
29/49826 20150115; F16F 2226/045 20130101; Y10T 403/7061
20150115 |
Class at
Publication: |
403/135 ;
403/225 |
International
Class: |
F16F 1/38 20060101
F16F001/38 |
Claims
1. A bushing assembly comprising: a deformable inner metal sleeve;
an elastomeric housing secured to said deformable inner metal
sleeve; a metal bar pin press fit into said deformable inner metal
sleeve, wherein said deformable inner metal sleeve has a
non-circular cross section while containing said metal bar pin.
2. The bushing assembly of claim 1 wherein said deformable inner
metal sleeve is made of steel.
3. The bushing assembly of claim 1 wherein said elastomeric housing
is rubber.
4. The bushing assembly of claim 1 wherein said elastomeric housing
is bonded to said deformable inner metal sleeve.
5. The bushing assembly of claim 1 wherein said metal bar pin is
cast metal.
6. The bushing assembly of claim 5 wherein said metal is iron.
7. The bushing assembly of claim 1 wherein said metal bar pin has a
central section with a four point cruciform cross section.
8. The bushing assembly of claim 7 wherein two of the extension end
surfaces of said cruciform cross section are in full contact with
said deformable inner metal sleeve and two of the extension end
surfaces of said cruciform cross section are only in line contact
with the deformable inner metal sleeve.
9. The bushing assembly of claim 1 wherein said metal bar pin has a
central section with a three point cross section.
10. The bushing assembly of claim 1 wherein said metal bar pin has
a central section with a five point cross section.
11. The bushing assembly of claim 1 wherein said metal bar pin has
a central section with a six point cross section.
12. The bushing assembly of claim 1 wherein said metal bar pin
extends beyond each end of said deformable inner metal sleeve.
13. The bushing assembly of claim 12 wherein each of said extended
ends of said metal bar pin has a hole through it.
14. (canceled)
15. (canceled)
16. The bushing assembly of claim 1 wherein the central section of
said metal bar pin is comprised of voids bounded by radially
extending contact surfaces.
17. A method of assembling said bushing assembly of claim 1 by
press fitting said bar pin into said deformable inner metal sleeve,
wherein said deformable inner metal sleeve deforms from a circular
cross section to a non-circular cross section.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention is generally directed to bushing
assemblies in vehicle suspension systems. More specifically, the
present invention is directed to a unique construction of bushing
assemblies used in vehicle suspension systems.
[0002] Vehicle suspension bushing assemblies are known. One such
bushing assembly may be formed from a round inner metal bar pin
that is an elongated piece of metal such as cast iron which is
contained within a combination of a circular metal sleeve attached
to an elastomeric material such as rubber. The circular metal
sleeve and the round bar pin must be machined to very exact
tolerances to properly fit together. The increased machining and
processing of the components due to the required low tolerances
increases costs. The circular bar pin may be heavy, which leads to
increased material, manufacturing and shipping costs.
[0003] Another known bushing assembly may be formed from a round
inner metal bar pin that is a machined length of metal such as
aluminum that is bonded directly to an elastomeric material such as
rubber. The direct bonding of the rubber to the inner metal bar pin
requires specific types of metal and additional machining or
processing to yield a proper bond between the inner metal and the
rubber, thus increasing costs.
[0004] The combined inner metal bar pin bonded to a rubber bushing
may also be inserted into a metal sleeve to form another known
bushing assembly. The bushing assembly may have attachment means on
both ends of the inner metal bar pin.
[0005] While prior vehicle suspension bushing assemblies have been
adequate for certain purposes, they have lacked some of the
advantages obtainable with the embodiments of the present
invention. Many of these advantages are clearly described herein
and others shall be readily apparent to those skilled in the
art.
[0006] One advantage achieved by the present invention is the use
of a deformable metal sleeve into which the metal bar pin is press
fit.
[0007] Another advantage achieved by the present invention is by
the use of low cost steel tube for the metal sleeve.
[0008] Another advantage achieved by the present invention is the
use of an as-cast or near as-cast ductile inner metal bar pin that
requires little or no machining or processing.
[0009] Another advantage achieved by the present invention is the
lower costs achieved by the need for little or no machining of the
inner metal bar pin.
[0010] Another advantage achieved by the present invention is the
use of an inner metal bar pin with a non-circular cross section
that has voids bounded by radially extending contact portions.
[0011] Another advantage achieved by the present invention is the
lower cost of the reduced weight achieved by the use of an inner
metal bar pin with a non-circular cross section with voids.
[0012] Another advantage achieved by the present invention is the
lower cost of the reduced material required by the use of an inner
metal bar pin with a non-circular cross section with voids.
[0013] Another advantage achieved by the present invention is the
use of ductile cast iron for the metal bar pin.
[0014] Another advantage achieved by the present invention is the
use of a process to insert the metal bar pin into the metal sleeve
and rubber combination and to insert the resulting bushing assembly
into a vehicle suspension component such as a torque rod in a
single press fit operation.
[0015] Another advantage achieved by the present invention is by
allowing the steel tube to deform into a non-circular shape during
the press fit operation instead of requiring a precise tolerance to
fit a uniform circular metal sleeve.
[0016] Another advantage achieved by the present invention is by
controlling the amount of the steel tube deformation such that the
bond line with the rubber component is not compromised.
[0017] Another advantage achieved by the present invention is
designing a cruciform embodiment such that the press fit between
the cruciform and the steel tube sleeve has two cruciform extension
end surfaces in full contact with the steel tube and two cruciform
extension end surfaces in only a line contact with the steel
tube.
[0018] These and other advantages of the preferred forms of the
invention will become apparent from the following description. It
will be understood, however, that an apparatus could still
appropriate the invention claimed herein without exhibiting each
and every one of these advantages, including those gleaned from the
following description. The appended claims, not any advantages
recited or implied herein, define the subject matter of this
invention. Any and all advantages are derived from the preferred
forms of the invention, not necessarily the invention in
general.
SUMMARY OF THE INVENTION
[0019] The present invention is directed to a vehicle suspension
bushing assembly. A bushing assembly has a ductile inner metal bar
pin with a center section having an optimized non-circular cross
section with voids for maximum strength at minimum weight. The
ductile inner metal bar pin has an extended end section on each
side of the center section. Each extended end section of the
ductile inner metal bar pin has a hole for means of attachment to
other suspension components, mounting brackets, or to the vehicle
frame. The ductile inner metal bar pin is press fit into a bushing
comprised of an elastomeric material housing such as rubber bonded
or otherwise secured to a metal sleeve such as a deformable steel
tube. The resulting deformable steel tube after the press fit
operation has a cross section that is non-circular. The press fit
assembly has adequate frictional force such that the inner metal
bar pin does not translate within the metal sleeve under service
duty.
[0020] The present invention also allows the inner metal bar pin to
be press fit into the metal sleeve and rubber bushing and to insert
the entire bushing assembly into a vehicle suspension component
such as a torque rod in a single one step operation.
[0021] In addition, other built-in features are available with the
present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In the following detailed description, reference will
frequently be made to the following drawings, in which like
reference numerals refer to like components, and in which:
[0023] FIG. 1 is a perspective view of a lightweight heavy duty
bushing assembly constructed in accordance with the principles of
the present invention;
[0024] FIG. 2 is a side elevational view of the bushing assembly
shown in FIG. 1;
[0025] FIG. 3 is an end view of the bushing assembly shown in FIG.
1;
[0026] FIG. 4 is a top view of the bushing assembly shown in FIG.
1;
[0027] FIG. 5 is a perspective view of part of the bushing assembly
shown in FIG. 1;
[0028] FIG. 6 is a side elevational view of the bushing shown in
FIG. 5;
[0029] FIG. 7 is an end view of the bushing shown in FIG. 5;
[0030] FIG. 8 is a perspective view of an embodiment of a four
point bar pin having a cruciform cross section constructed in
accordance with the principles of the present invention;
[0031] FIG. 9 is a side elevational view of the bar pin shown in
FIG. 8;
[0032] FIG. 10 is an end view of the bar pin shown in FIG. 8;
[0033] FIG. 11 is a sectional view of part of a bushing assembly
having a three point alternative embodiment of a bar pin;
[0034] FIG. 12 is a sectional view of part of a bushing assembly
having a five point alternative embodiment of a bar pin;
[0035] FIG. 13 is a sectional view of part of a bushing assembly
having a six point alternative embodiment of a bar pin;
[0036] FIG. 14 is an end view of the bushing assembly shown in FIG.
1 better showing the as assembled condition; and
[0037] FIG. 15 is an end view similar to FIG. 14 better showing
further details of a preferred as assembled condition.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] FIGS. 1-4 illustrate a lightweight heavy duty bushing
assembly 10 for vehicle suspensions. A ductile inner metal bar pin
30 is press fit into a bushing 20. The ductile inner metal bar pin
30 has a central portion 31 with a cruciform cross-section that is
comprised of voids 32 bounded by radially extending contact
surfaces 33. The ductile inner metal bar pin 30 has an end portion
35 that extends beyond each end of the central portion 31. Each
extended end portion 35 of the ductile inner metal bar pin 30 has a
hole 37 through it for attachment to vehicle suspension components,
mounting brackets, or to the vehicle frame (not shown). The ductile
inner metal bar pin 30 is preferably cast of metal material, such
as iron. Alternatively, the ductile inner metal bar pin 30 could be
cast from other materials or the ductile inner metal bar pin 30
could be forged or machined from a variety of materials.
[0039] The bushing 20 is comprised of a metal sleeve 40 that is
attached such as by bonding to an elastomeric housing 50 such as
rubber. The elastomeric housing 50 is shaped to the desired
dimensions by a process such as molding. The metal sleeve 40 may be
made of a deformable metal such as steel.
[0040] FIGS. 5-7 illustrate an embodiment of the bushing 20. As
previously noted, the bushing 20 may be comprised of a metal sleeve
40 that is bonded to an elastomeric housing 50. Alternatively, the
entire bushing 20 may be formed from a single material by a process
such as casting or molding. The cross section of the metal sleeve
40 prior to receiving the ductile inner metal bar pin 30 is
generally circular as shown in FIG. 7.
[0041] FIGS. 8-10 illustrate an embodiment of the ductile inner
metal bar pin 30. The ductile inner metal bar pin 30 has a central
section with a four point or cruciform shape as shown in FIG. 10.
The cross section of the ductile inner metal bar pin 30 is
optimized to reduce weight and improve structural efficiency. The
holes 37 in the extended end portions 35 of the ductile inner metal
bar pin 30 are sized and positioned to provide appropriate means to
attach the ductile inner metal bar pin 30 to vehicle suspension
components or to the vehicle frame while maximizing the strength of
the ductile inner metal bar pin 30.
[0042] FIG. 11 illustrates a three point embodiment of the central
section of a ductile inner metal bar pin 60 comprised of voids 32
bounded by radially extending contact surfaces 33 within a metal
sleeve 40. The cross section of the ductile inner metal bar pin 60
is optimized to reduce weight and improve structural
efficiency.
[0043] FIG. 12 illustrates a five point embodiment of the central
section of a ductile inner metal bar pin 70 comprised of voids 32
bounded by radially extending contact surfaces 33 within a metal
sleeve 40. The cross section of the ductile inner metal bar pin 70
is optimized to reduce weight and improve structural
efficiency.
[0044] FIG. 13 illustrates a six point embodiment of the central
section of a ductile inner metal bar pin 80 comprised of voids 32
bounded by radially extending contact surfaces 33 within a metal
sleeve 40. The cross section of the ductile inner metal bar pin 80
is optimized to reduce weight and improve structural
efficiency.
[0045] It is to be understood that FIGS. 11-13 are partial figures
of the entire bushing assembly and that the embodiments illustrated
in FIGS. 11-13 also contain an elastomeric housing bonded or
otherwise secured to the metal sleeve.
[0046] FIG. 14 illustrates an embodiment of a lightweight heavy
duty bushing assembly 10 where the press fit of the ductile inner
metal bar pin 30 caused the metal sleeve 40 to deform from a
circular cross section to a non-circular cross section, thus
enabling a high tolerance between the components for assembly.
[0047] FIG. 15 illustrates another embodiment of the lightweight
heavy duty bushing assembly 10 shown in FIG. 14. Two of the
cruciform extension end surfaces 38 are in full contact with the
metal sleeve 40 and the other two cruciform extension end surfaces
39 make only a line contact with the metal sleeve 40. The ductile
inner metal bar pin 30 is therefore structurally efficient in that
the metal material is concentrated where it is needed to react to
torque rod loads. Looser tolerances are thus permitted on the inner
diameter of the metal sleeve 40 and the outer surfaces of the
cruciform extension end surfaces 38, 39 allowing for easier
assembly of the ductile inner metal bar pin 30 into the metal
sleeve 40. Frictional forces between the ductile inner metal bar
pin 30 and the metal sleeve 40 prevent translation of the ductile
inner metal bar pin 30 within the metal sleeve 40 while under
service duty or operation.
[0048] While this invention has been described with reference to
several illustrative embodiments, it will be understood that this
description shall not be construed in a limiting sense. Rather,
various changes and modifications can be made to the illustrative
embodiments without departing from the true spirit and scope of the
invention, as defined by the following claims. Furthermore, it will
be appreciated that any such changes and modifications would be
recognized by those skilled in the art as an equivalent to one or
more elements recited in the following claims, and shall be covered
by such claims to the fullest extent permitted by law.
* * * * *