U.S. patent application number 09/791891 was filed with the patent office on 2002-02-07 for decorative covering for air bag covers.
Invention is credited to Anglsperger, Erwin F..
Application Number | 20020014764 09/791891 |
Document ID | / |
Family ID | 7878654 |
Filed Date | 2002-02-07 |
United States Patent
Application |
20020014764 |
Kind Code |
A1 |
Anglsperger, Erwin F. |
February 7, 2002 |
Decorative covering for air bag covers
Abstract
The invention relates to a decorative layer for an air bag
covering, especially for use in motor vehicles. A local initiating
area is provided in said decorative layer, the tear for tearing
through the decorative layer when the air bag is deployed being
initiated in this area. The invention also relates to an air bag
covering, comprising a shaped part with predetermined break-lines
and a decorative layer applied to said shaped part. At least one
locally limited initiating area is provided in said decorative
layer, the tear for tearing through the decorative layer when the
air bag is deployed being initiated along the predetermined
break-lines of the shaped part, in this area.
Inventors: |
Anglsperger, Erwin F.;
(Eggenfelden, DE) |
Correspondence
Address: |
SUGHRUE, MION, ZINN, MACPEAK & SEAS, PLLC
2100 PENNSYLVANIA AVENUE, N.W.
WASHINGTON
DC
20037-3213
US
|
Family ID: |
7878654 |
Appl. No.: |
09/791891 |
Filed: |
February 26, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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09791891 |
Feb 26, 2001 |
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PCT/EP99/06181 |
Aug 23, 1999 |
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Current U.S.
Class: |
280/743.1 ;
280/728.1 |
Current CPC
Class: |
B60R 21/216 20130101;
B60R 2021/21543 20130101; B60R 21/21656 20130101 |
Class at
Publication: |
280/743.1 ;
280/728.1 |
International
Class: |
B60R 021/16 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 25, 1998 |
DE |
198 38 603.6 |
Claims
What is claimed is:
1. A decorative covering for an air bag cover. especially for use
in motor vehicles, comprising at least one locally confined
initiating site (5) in which bursting said decorative covering (4)
is initiated when said air bag is deployed.
2. The decorative covering as set forth in claim 1, characterized
in that said initiating site (5) of said decorative covering (4) is
formed by a reduction in thickness, such as by nicking or removal
of material.
3. The decorative covering as set forth in claim 1, characterized
in that said initiating site (5) of said decorative covering (4) is
formed by a locally confined window, for example, by a through-hole
(5).
4. The decorative covering as set forth in claim 3, characterized
in that the contour of said through-hole (5) of said initiating
site comprises sharply tapered sections for defined initiation of
bursting.
5. The decorative covering as set forth in any of the preceding
claims, characterized by it being made of leather a substitute
leather, such as artificial leather, Alcantara, Lorica or something
similar, or of a plastics film of PUR, PVC, ASA, or ABS.
6. An air bag cover, especially for use in motor vehicles including
a molding (1) comprising designed burst lines (3, 3a) and a
decorative covering (4) as set forth in in any of the preceding
claims applied to said molding (1), whereby bursting said
decorative covering (4) along said designed burst lines (3, 3a) of
said molding (1) is initiated in said initiating site (5) of said
decorative covering (4) when said air bag is deployed.
7. The air bag cover as set forth in claim 6, characterized in that
said initiating site (5) is arranged concealed under an exposed
insert (8) secured to said molding (1).
8. The air bag cover as set forth in claim 6 or claim 7,
characterized in that said molding (1) comprises at least one
locally confined initiating site (2) coinciding in location with
said initiating site (5) of said decorative covering and in which
bursting said designed burst lines (3) of said molding (1) is
initiated when said air bag is deployed.
9. The air bag cover as set forth in claim 8, characterized in that
said initiating site (2) of said molding (1) is configured as an
through-hole (2).
10. The air bag cover as set forth in any of the claims 7 to 9,
characterized in that said exposed insert (8) is an emblem or
logo.
11. The air bag cover as set forth in any of the claims 7 to 10,
characterized in that an arresting element (7) is secured to said
exposed insert (8) so that it cannot be torn out of place, and
connectable to said molding (1) to prevent said exposed insert (8)
from being released at random from said molding (1) when said air
bag is deployed.
12. The air bag cover as set forth in any of the claims 6 to 11,
characterized in that due to the arrangement of said designed burst
lines (3, 3a) several flaps (9) are formed which open up when said
air bag is deployed.
13. The air bag cover as set forth in any of the claims 6 to 12,
characterized in that the arrangement of said designed burst lines
(3, 3a) is in the shape of an H, said exposed insert (8)
concealling at least part of the transverse designed burst line
(3a).
14. The air bag cover as set forth in any of the claims 6 to 13,
characterized in that said exposed insert (8) is secured by bonding
or by ultrasonic welding to said molding (1).
15. The air bag cover as set forth in any of the claims 6 to 13,
characterized in that said exposed insert (8) is secured by at
least one fastener such as a clip (6a) or rivet (6b) to said
molding (1).
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a decorative covering for air bag
covers, especially for use in motor vehicles. The invention also
relates to an air bag cover comprising a molding including designed
burst lines and a decorative covering applied to the molding, for
example, for use in a motor vehicle.
[0003] A molding as defined in the following is a component
protecting or covering an air bag operating means as well as the
air bag impact padding, it comprising designed burst lines or
locations which on deployment of the air bag burst by the impact
padding in assuring emergence of the impact padding.
[0004] Such air bag systems are well-known in motor vehicles, it
being particularly air bags incorporated in the steering wheel or
dashboard for reducing the risk of injury to the driver and
front-seat occupant in a head-on collision that find wide
application, although air bag systems incorporated in the doors,
door pillars or seats for protecting the driver and front-seat
occupant from injury by side impact have also since become popular.
Air bag systems are likewise incorporated on the rear side of the
front seats so that occupants in the rear of the vehicle can be
protected by air bag systems.
[0005] 2. Prior Art
[0006] Moldings for air bag covers are often injection molded in
plastics materials, other known methods of production being, for
example, foaming parts of plastics materials or foaming metal parts
in place. To ensure satisfactory functioning of the air bag systems
these moldings are provided with designed burst lines or locations
which burst open at a predefined bursting force and ensure
satisfactory deployment of the air bag located underneath. To
enhance the visual finish and feel or to adapt air bag covers to
the interior finish of the vehicle the moldings are often lacquered
or provided with a decorative covering. Depending on the interior
finish of the vehicle such decorative coverings are made of genuine
leather, substitute leather such as Alcantara or artificial
leather, or of films of plastics.
[0007] The designed burst lines usually divide the molding of the
air bag cover into one or more portions which on inflation of the
air bag in the air bag module form one or more flaps on bursting of
the designed burst line which open up to the side to allow the air
bag to deploy charged with the gas made available by the
inflator.
[0008] In accordance with prior art decorative coverings of leather
are fabricated multiply sectioned and stitched together in the
region of the designed burst lines of the molding. Depending on the
designed bursting force the stitch length, strength and material of
the thread are selected so that for a defined bursting force the
thread snaps to permit satisfactory emergence of the impact
padding. When such decorative coverings are stitched together the
seam needs to be precisely positioned on the designed burst lines
so that when the air bag is deployed the impact padding is able to
satisfactorily emerge by the thread snapping. Precisely positioning
the stitched leather decorative covering on the molding is
extremely difficult since during lamination or rear foaming the
decorative covering may be distorted which spoils the visual appeal
and may even result in rejection of the leather decorative covering
already fabricated at high expense. In addition, where for instance
an air bag cover for an impact pot is incorporated in a steering
wheel, a highly complicated form of burst seam is needed which can
only be produced by intensive labor at high expense.
[0009] Disclosed by European patent application 0 428 935 is an air
bag cover in which a molding covering the air bag operating means
and the air bag impact padding is provided which comprises burst
lines designed to burst open on deployment of the air bag in
assuring emergence of the air bag impact padding. The molding is
covered by a decorative covering of a vinyl plastics which is
weakened all along the designed burst lines of the molding by it
being nicked. Nicking the decorative covering is implemented on a
pliant base. The problem in this prior art is that nicking the
decorative covering down to a predefined remaining thickness is
difficult to implement.
[0010] Described in the German laid-open patent 195 16 230 is a
method for reducing the material thickness of the decorative
covering along the designed burst lines of the molding to
facilitate initial bursting of the decorative covering when the air
bag is deployed. For this purpose the decorative covering is placed
on greatly restrict the freedom in designing such air bag covers,
resulting in compromises either as to the visibility of burst lines
on the surface of the cover lid or on the design geometry of the
flaps and the surface of the cover lid. Hitherto in this
arrangement the weakened portions in the decorative covering
extended along the full length of the designed burst lines of the
molding of the air bag cover.
[0011] Known from EP 0 770 522 A1 is an air bag arrangement
comprising a decorative covering, a foamed layer and a backing. The
air bag cover has notches at the edge in the decorative covering as
well as in the backing for initiating bursting.
SUMMARY OF THE INVENTION
[0012] The invention is based on the object of providing an air bag
cover as well as a corresponding decorative covering for air bag
covers which are simple and cost-effective in production whilst
permitting high freedom in designing the surface of the air bag
cover and decorative covering as well as the flap geometry in
ensuring instant bursting of the decorative covering and molding of
the air bag cover located therebelow when the air bag is
deployed.
[0013] This object is achieved by a decorative covering having the
features as set forth in claim 1 and by an air bag cover having the
features as set forth in claim 6.
[0014] The gist of the invention is, for the first time, to weaken
the decorative covering not along the entirety of the designed
burst lines of the molding, but merely in a locally confined
initiating site. Tests have indicated that weeakening the
decorative covering in an initiating site results in stress peaking
at the base of the notch in the initiating site when the air bag is
deployed. It is this stress peak that initiates bursting at ed,
bursting progresses to totally part the decorative covering without
the decorative covering having been previously weakened outside of
the initiating site.
[0015] It is thus now possible, for the first time, to burst the
decorative covering by weakening only a locally confined site, the
initiating site, so that bursting is initiated there. When such a
decorative covering is employed on an air bag cover, the decorative
covering is applied to the molding comprising the designed burst
lines so that the decorative covering covers at least one locally
confined initiating site at which bursting the decorative covering
is initiated along the designed burst lines of the molding when the
air bag is deployed. Since in accordance with the invention the
decorative covering is machined only in a locally confined
initiating site so that due to the notch effect bursting is
initiated in this precisely defined locally confined initiating
site, there is now no need for complicated machining of the
decorative covering along the designed burst lines of the molding.
In addition, there is now no need for design grooves which
correspondingly restrict the freedom in design since there is now
no longer any need to compensate tolerances stemming from
fabrication of the decorative covering by the design grooves. It is
the stress peak at the base of the notch of the initiating site
that initiates bursting of the decorative covering, bursting then
progressing along the designed burst lines of the molding.
[0016] When the air bag is deployed it is thus assured that both
the molding and the decorative covering applied thereto burst
totally and instantly in a defined site so that one or more flaps
are formed which open up to the side to allow the air bag to deploy
charged with the gas made available by the inflator.
[0017] In accordance with one preferred embodiment the initiating
site of the decorative covering is formed by reducing the thickness
of the decorative covering for which various known methods may be
put to use, for example, nicking the rear of the decorative
covering or weakening the decorative covering with the template
sharpening gaps as described in German laid-open patent 195 16 230.
Reducing the thickness of the decorative covering in this way
results in the decorative covering bursting in this weakened site
due to the stress peak at the base of the notch when the decorative
covering is subjected to the forces in deploying the air bag, thus
causing bursting to be initiated at this location. As soon as the
decorative covering has started to burst at this locally confined
initiating site bursting progresses along the rupturing designed
burst lines of the molding.
[0018] In another embodiment it is provided for that the locally
confined initiating site of the decorative covering is formed by a
window in the decorative covering, for example, by a through-hole.
Here too, the forces acting on the decorative covering result in
stress peaking at the base of the notch when the air bag is
deployed so that bursting is initiated in the precisely defined
initiating site. Due to the designed burst lines of the molding
bursting underneath the decorative covering, bursting in the
decorative covering progresses along the designed burst lines of
the molding. Preferably the contour of the initiating site of the
decorative covering comprises sharply tapered sections to boost the
notching effect of the initiating site. The contour of the
initiating site may be, for example, rhombic, or circular with
linear nicks, although, of course, other geometries for configuring
the site for initiating bursting are conceivable.
[0019] In one particularly preferred embodiment it is provided for
that the initiating site of the decorative covering is arranged
concealed under an exposed insert secured to the molding. Such
exposed inserts are often applied to the air bag covers and
configured as emblems or logos or quite generally as trim. The
exposed inserts often including vehicle make symbols or indications
as to the air bag concealed beneath the cover. The exposed insert
may also be configured in two or more parts where necessary. When
the locally confined initiating site for initiating bursting of the
decorative covering on deployment of the air bag is concealed under
an exposed insert secured to the molding, the initiating site may
be designed solely in accordance with the criteria relevant to
initiating bursting without having to take into account the design
and visual appeal.
[0020] Preferably an arresting element is secured to the exposed
insert so that it cannot be torn out of place, and connectable to a
mounting part to prevent the exposed insert from being released at
random from the mounting part when the air bag is deployed. This
makes sure that although the exposed insert effectively conceals
the initiating site of the decorative covering there is no
additional risk of vehicle occupants being injured. Otherwise, when
the air bag is deployed the exposed insert might be torn away as a
whole from its mount and capatapulted into the vehicle interior or
the exposed insert could fragmentize and likwise pose a risk of
injury to the vehicle occupants. By safeguarding the exposed insert
with a safe arresting element the exposed insert is prevented from
being catapulted or fragmentized in being released from its mount;
instead, when the air bag is deployed the exposed insert is held
captive by the arresting element so that only a defined item can
gain access to the vehicle interior.
[0021] In accordance with another preferred embodiment the molding
too, comprises a locally confined initiating site coinciding in
location with the initiating site of the decorative covering and in
which bursting the designed burst lines of the molding is initiated
when the air bag is deployed. In this way initiating bursting in
the molding and bursting in the decorative covering can take place
in a common initiating site arranged ideally concealed beneath an
exposed insert. By providing a common initiating site for the
molding and decorative covering, bursting of the decorative
covering is improved since bursting the molding and decorative
covering respectively is initiated at the one and the same location
to thus also define the direction in which bursting progresses for
both the decorative covering and molding. Should the location of
initiating bursting of the molding not coincide with the initiating
site of the decorative covering this might result in problems in
bursting the decorative covering and molding.
[0022] Preferably the initiating site of the molding is configured
as a through-hole which in one preferred embodiment is configured
so that it can be made use of to secure, for example, a clip or
rivet of an exposed insert, although of course, the exposed insert
may also be secured to the molding by ultrasonic welding, bonding
or some other means of connection.
[0023] Preferably the decorative covering is made of leather or a
substitute leather, such as artificial leather, Alcantara, Lorica
or something similar, although of course depending on the location
and configuration in the vehicle interior it may also be made of a
plastics film of polyurethane (PUR), polvinyl chloride (PVC),
acrylonitrile acrylic ester (ASA) or acrylonitrile butadiene
styrene (ABS).
[0024] In accordance with the embodiment as last preferred the
designed burst lines are arranged so that when the air bag is
deployed several flaps are opened up. Preferably the designed burst
lines of the molding are configured in the shape of an H or X,
resulting in two or four flaps materializing for opening up when
the air bag is deployed, i.e. so that the air bag is able to unfold
charged with gas made available by the inflator. Where a H-shaped
designed burst line is concerned the exposed insert may be
arranged, for example, so that at least part of the transverse
designed burst line is concealed. When a X-shaped designed burst
line configuration is provided the exposed insert may be arranged
for example at the intersection of the designed burst lines.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Several example embodiments of the invention will now be
detailed for further explanation and a better understanding, with
reference to the attached drawings in which:
[0026] FIG. 1 is a view in perspective of the air bag cover in
accordance with the invention;
[0027] FIG. 2 is a section taken along the line II-II as shown in
FIG. 1;
[0028] FIG. 3 is a section taken along the line III-III as shown in
FIG. 1;
[0029] FIG. 4 is a section through an air bag cover in accordance
with the invention including an exposed insert and an arresting
element;
[0030] FIG. 5 is a section through a further embodiment of an air
bag cover including an exposed insert; and
[0031] FIG. 6 is a view in perspective of the flaps of an air bag
cover opened up after deployment of the air bag.
DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION
[0032] Referring now to FIG. 1 there is illustrated an air bag
cover in accordance with the invention as may be put to use, for
example, for an air bag system incorporated in a steering wheel.
Making use of the air bag cover is preferably provided for in motor
vehicles, although of course such air bag covers can be put to use
in other means of passenger transport such as aircraft, trains or
ships. Applied to a molding 1 is a decorative covering 4, the
molding 1 comprising designed burst lines 3, 3a. In accordance with
the invention the decorative covering 4 comprises an initiating
site 5 which is locally confined and in which bursting the
decorative covering 4 is initiated when the air bag is deployed. In
the example embodiment as shown in FIG. 1 the decorative covering 4
is windowed in the initiating site 5, this through-hole being
configured so that two V-shaped portions are formed which combine
to form in all a rhombic initiating site. To enhance the notch
effect the apexes of the two Vs point in the direction of the
designed burst lines 3. 3 a of the molding 1. Instead of a
through-hole in the decorative covering 4 it is often sufficient to
merely weaken the decorative covering 4 in the initiating site 5.
One such weakening may take the form of, for example, a nick in the
rear side of the decorative covering 4 and a reduction in the
thickness of the decorative covering 4 by means of sharp template
ridges or in making use of a laser. In the thus weakened initiating
site 5 the forces acting on the decorative covering 4 and
initiating site 5, when the air bag is deployed due to the notch
effect caused by the weakening of the material, result in stress
peaking at the base of the notch. This stress peak results in
bursting being initiated at the base of the notch, bursting then
progressing also through the non-weakened portions of the
decorative covering 4.
[0033] Referring now to both FIG. 1 and FIG. 2 there is illustrated
how the molding 1 likewise comprises an initiating site 2 in which
bursting is initiated for bursting the designed burst line 3a of
the molding 1 when the air bag is deployed. Weakening the molding 1
in the initiating site 2 results in stress peaking at the base of
the notch of the initiating site when the air bag is deployed. Due
to this stress peak at the base of the notch, bursting is initiated
in this precisely defined, locally confined initiating site 2. Due
to the forces continuing to act on the molding 1, when the air bag
is deployed, bursting progresses along the designed burst lines 3a
and 3. The notchings or weakenings of the molding 1 along the
designed burst lines 3 and 3a result in stress peaking along these
designed burst lines to thus cause bursting to progress along these
precisely predefined designed burst lines 3 and 3a.
[0034] Referring now to both FIG. 2 and FIG. 3 there is illustrated
how the designed burst lines 3 and 3a of the molding 1 are provided
such that only the side of the molding 1 facing away from the
decorative covering 4 is notched. In this way it is achieved that
the designed burst lines 3 and 3a remain invisible to the exterior
which enhances the freedom in design and surface finish.
[0035] In FIG. 1 the initiating site 2 of the molding 1 is
configured as a round through-hole, This configuration in the form
of a round through-hole has the advantage that the through-hole in
addition to initiating bursting may simultaneously serve to secure
an exposed insert 8 to the molding 1. A non-circular contour of the
through-hole may additional serve in this arrangement as a means
for preventing turning of the exposed insert. Referring now to FIG.
4 there is illustrated an exposed insert 8 secured to the molding 1
by a clip 6a. To prevent random breakout or unbuttoning of the
exposed insert 8 from the molding 1 when the air bag is deployed an
arrester element 7 has been integrated in the exposed insert 8 to
thus reduce the risk of injury to the vehicle occupants. In this
arrangement the arrester element 7 may be, for example, a tough
thread or wire cast in place in the exposed insert 8 or secured to
the exposed insert 8 by some other ways and means. Since, due to
the very high acceleration forces acting on the exposed insert 8
when the air bag is deployed, the exposed insert 8 may not only
break away from the molding 1 but also fragmentize, the arrester
element 7 may also be integrated as a fabric or film in the exposed
insert 8 so as to prevent not only random release of the exposed
insert 8 from the molding 1 but to prevent fragments from gaining
random access to the vehicle interior. In this arrangement the
arrester element 7 may be fixedly connected to the molding 1 either
by welding or bonding or subsequently applied to the molding 1.
Preferably the exposed insert 8 is configured as an emblem or logo
providing either vehicle make symbols or indications as to the air
bag concealed beneath the cover.
[0036] As evident from FIG. 4 it is possible to totally conceal the
initiating site 5 of the decorative covering 4 and the initiating
site 2 of the molding 1 beneath the exposed insert 8 to thus enable
the initiating site 2 and initiating site 5 to be configured so
that initiating bursting is an optimum without detrimenting the
outer design of the air bag contour since the exposed insert 8
conceals the initiating sites 2 and 5.
[0037] Referring now to FIGS. 4 and 5 there is illustrated two
different ways of securing exposed inserts 8 to the moldings 1.
FIG. 4 shows a fastener including a clip 6a whilst FIG. 5 shows a
fastener including a rivet 6b. In this arrangement the clip 6a and
rivet 6b may be arranged either in the initiating site 2 of the
molding 1 when, as shown in this case, it is configured as a
through-hole, or, if needed for reasons of design or engineering,
it is arranged outside of the initiating site 2 of the molding 1.
When configured with a fastener, e.g. a clip, an "unbottoning" of
the exposed insert fastener is achievable in the initiating site of
the molding configured as a through-hole when the designed burst
lines burst and with subsequent opening up of the flaps as long as
an arresting element prevents the exposed insert from being
released and catapulted into the vehicle interior where it could
otherwise cause injury to the vehicle occupants. Depending on the
size and configuration of the exposed insert 8 it may also be
necessary to secure it by several fasteners such as clips 6a or
rivets 6b to the molding 1. The exposed insert 8 may also be
secured to the molding 1 by ultrasonic welding, bonding or some
other suitable method.
[0038] As evident from FIG. 1 the designed burst lines 3 and 3a on
the molding 1 are preferably configured in the shape of an H. When
the air bag is deployed the designed burst lines 3 and 3a of the
molding 1 and the decorative covering 4 burst to thus form the two
flaps 9 as shown in FIG. 6 which open up so that the air bag is
able to unfold and be charged with the gas made available by the
inflator.
* * * * *