Adhesive bonding and miscellaneous chemical manufacture – Methods – Surface bonding and/or assembly therefor
Reexamination Certificate
1998-09-09
2001-04-03
Ball, Michael W. (Department: 1733)
Adhesive bonding and miscellaneous chemical manufacture
Methods
Surface bonding and/or assembly therefor
C280S728100, C280S729000, C428S035200
Reexamination Certificate
active
06210519
ABSTRACT:
The invention relates to a method of manufacturing an airbag which comprises as plurality of airbag parts and has an airbag envelope.
Such airbags serve as a safety device for the driver and passengers in motor vehicles. If a retardation sensor detects an impact of the vehicle, or an impact of an object on the vehicle, then an associated gas generator brings about an inflation of the airbag, so that the inflated airbag arrests resulting movements of the vehicle occupants, or protects the vehicle occupants from an object penetrating into the vehicle. For the manufacture of such an airbag a plurality of parts of the same are for example connected together by sewing or by adhesive bonding. The connection of the airbag parts must be sufficiently strong to withstand an abrupt inflation by the gas generator, or an additional pressure loading through the impact of an object. The parts which form the actual airbag envelope to be inflated and also their points of connection must be sufficiently well sealed with respect to the gas given off by the gas generator. In order to satisfy these requirements with high reliability, known airbag manufacturing methods are comparatively complicated and correspondingly expensive.
SUMMARY OF THE INVENTION
It is the object of the invention to provide a method of the initially named kind which is simple and reliable to carry out and which ensures the strength and the gas tightness of the points of connection of the airbag with a high degree of safety and by which an airbag is provided which further enhances the safety of the vehicle occupants in comparison to known airbags.
This object is satisfied in accordance with the invention in that a first airbag part is provided during a preparation stage with a polyurethane coating at at least one attachment section, and in that the attachment section of the first airbag part is brought into contact with a connection section of a second airbag part during a manufacturing stage and the first airbag part is connected through heating of the polyurethane coating of its attachment section to the second airbag part along its connection section.
In accordance with the invention it is only necessary for the manufacture of a connection of two airbag parts to one another to coat the first airbag part with polyurethane (PU) at at least one attachment section, to align the second airbag part relative to this coating or to the first airbag part and to heat the PU-layer, so that the two airbag parts are welded to one another along the attachment section. This connection of the two parts along the attachment section proves to be sufficiently gas-tight and also adequately strong with resistance to tension and tearing. Thus, the need to provide an adhesive or binding means at the attachment section of the first airbag part, which is only allowed to be brought into contact with the second airbag part at the connection section is avoided. It is also not necessary to sew together two airbag parts which are to be connected to one another, or to seal corresponding seams, so that they are gas-tight. The method of the invention can be advantageously used on all parts of the airbag which are to be connected to one another, even though only two or three airbag parts are named and defined in the following.
It is possible that said first airbag part and said second airbag part are each formed as a section of the actual airbag envelope, so that two sections of the airbag envelope can be connected to one another through the method of the invention. It is furthermore of advantage when a single envelope section consists of two airbag parts which are connected to one another through the method of the invention. By way of example this airbag envelope section can be folded such that the two airbag parts come to lie above one another. In this case a connection location of the two airbag parts is already given by the fold of the envelope section.
Alternatively, it is possible for the first said airbag part to be formed as a connection band and for the second airbag part to be formed as a section of the airbag envelope. This connection band can be provided to extend within the inner space of the finished airbag, for example in order to stabilise the inflated airbag in its shape or alignment. For side-airbags in particular, which are to adopt a position between a passenger and the sidewall of the vehicle in the inflated state, a connection band can be provided inside the airbag which connects the airbag envelope section adjacent the passenger to the airbag envelope section adjacent the side wall along the longitudinal direction of the airbag. In this way the width of the airbag, i.e. the spacing of the two said airbag envelope sections, can be restricted.
In this embodiment of the invention it is preferred to simultaneously connect the connection band to a third airbag part simultaneously with its connection to the said airbag envelope section, in particular to a further section of the airbag envelope, so that the connection band is connected after the end of the method between the said airbag envelope section and the third airbag part. For this, the connection band is coated with PU at a further attachment section during the preparation stage and this further attachment section is brought into contact with a connection section of the third airbag part during the manufacturing stage and heated in order to produce a connection between the attachment section and the connection section of the third airbag part. In this embodiment of the invention it is also possible to provide the second airbag part and the third airbag part as parts of a single section of the airbag envelope, for example in order to attach the connection band between the two parts of the folded airbag envelope section.
The connection band can be executed as a hose, so that it has a substantially round cross-section. In this respect, it is of advantage when the coating which is respectively provided as the attachment section extends along the length of the connection band at two oppositely disposed outer sides of the hose. It can be advantageous, in dependence on the type of construction of the airbag provided, for the hose-like connection band to be closed or open at its longitudinal ends, with it in particular being possible to provide the two longitudinal ends with a PU-coating at their inner sides and to connect them in their own right in the course of processing step, so that they are closed.
Furthermore, it is possible for the connection band to have a substantially U-shaped cross-section. In this case the PU-coating, which is respectively provided as the attachment section, can extend at the outer sides of the limbs of the U-shape over the length of the connection band.
Finally it is also possible to form the connection band as a flat band in which both sides are respectively coated with PU as an attachment section.
In the method of the invention it is basically sufficient to coat the region of the first airbag part termed an attachment section with PU in order to firmly connect the first airbag part to a further airbag part by heating of this coating along the attachment section. At the further airbag part the connection is produced along a section, which is presently termed the connection section, which does not require any special constructional design or treatment.
In the context of the invention it is preferred to provide other regions of the named airbag parts than the attachment section of the first airbag part with a polyurethane coating. In particular, the second airbag part and optionally the third airbag part can each be coated at their region termed a connection section, so that during the processing step a coated attachment section is welded to a coated connection section. In this way, an even higher strength of the connection is achieved.
If the airbag parts are coated with PU during the preparation step, so that the entire inner side of the finished manufactured airbag envelope has a PU coating, then the method of the invention not only produces a connection of
Einsiedel Heinrich
Gloecker Oliver
Heudorfer Benedikt
Klaiber Uwe
Ball Michael W.
Foley & Lardner
Rossi Jessica
Takata (Europe) Vehicle Safety Technology GmbH
LandOfFree
Method of manufacturing an airbag does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of manufacturing an airbag, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of manufacturing an airbag will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2448426