Resumen
The device includes a horizontal table (3) intended to support an airbag (1) vacuum spread out, so that the airbag is maintained in position on the table on the level of a fixed part (5), and at least a compaction arrangement (24,25) displaceable in at least a direction parallel with the table (3) to enable compaction of the airbag while moving a peripheral point of the airbag towards the fixed part. The compaction arrangement includes two interdependent small perpendicular arms (24A,24B,25A,25B) extending, under operation, parallel to the table. The compaction elements (24, 25) are alternatively displaceable along one or other of the horizontal directions (X- X,Y-Y), perpendicular to each small arm. An Independent claim is included for a process for using the above airbag compaction device.
Reivindicaciones
1. Apparatus for folding an airbag belonging to a safety device for a motor vehicle, comprising a substantially horizontal table (3) adapted to support a spread-out empty bag (1), so that the bag is held m position on the table at a fixed part (5), and at least one compacting member (24, 25) which is movable in at least one direction parallel to the table (3), so as to allow a compacting operation of the bag (1) by moving from a peripheral point of the bag (1) towards the fixed part (5), charactensed in that the compacting member (24, 25) comprises two battens (24A, 24B, 25A, 25B) integrally attached to one another, which are substantially perpendicular and extend parallel to the table, during operation, the compacting member (24, 25) being movable alternately in one or other of the horizontal directions (X-X, Y-Y) which are respectively perpendicular to each batten (24A, 24B, 25A, 25B). 2. Folding apparatus according to claim 1, characterised in thatthe compacting member (24, 25) is mounted to be movable by rotation relative to the table (3) about the vertical axis (Z-Z) passing through the fixed part (5), so as to be able to successively adopt two angular positions offset by 180° relative to said axis (Z-Z), corresponding to four successive elementary operations of compacting the bag (1), from different peripheral points of the bag. 3. Folding apparatus according to claim 1 or 2, characterised in thatit comprises a second such compacting member (24, 25) the battens (24A, 24B, 25A, 25B) of which are respectively parallel to the two battens of the first compacting member. 4. Folding apparatus according to claim 3, characterised in thateach compacting member (24, 25) is vertically movable between an active position in contact with the table (3) and an inactive released position above the table, so that the compacting members (24, 25) can alternately be in the active or inactive position relative to one another. 5. Folding apparatus according to any one of claims 1 to 4, characterised in thatit further comprises at least one pressing member (32A, 32B) connected for horizontal translation to the compacting member (24, 25) and movable relative thereto along a substantially vertical axis (Z-Z) between a top position above the table (3) and a bottom position pressing on the bag (1). 6. Folding apparatus according to claim 5, characterised in thatthe pressing member (32A, 32B) is movable relative to the compacting member (24, 25) in an alternating movement between the top and bottom positions. 7. Folding apparatus according to claim 5 or 6, characterised in thatthe pressing member (32A, 32B) is adapted to be released from the bag (1) in its top position. 8. Folding apparatus according to any one of claims 5 to 7, characterised in thatit comprises two such pressing members (32A, 32B) offset in the direction of movement of the compacting member (24, 25). 9. Folding apparatus according to claim 8, characterisedm that the pressing members (32A, 32B) are adapted to be subjected to a relative movement of translation relative to one another along their substantially vertical axis of travel. 10. Folding apparatus according to any one of claims 5 to 9, characterisedm that it comprises, for each batten (24A, 24B, 25A, 25B), an associated pressing member (32A, 32B) which is active during the movement of the compacting member (24, 25) of said batten in the direction perpendicular to said batten. 11. Folding apparatus according to any one of claims 1 to 10, characterised in thatit comprises at least one retaining member (19) which is movable in the direction of a substantially vertical axis between a position released from the bag (1) located above the table(3) and a position bearing on part of the bag which is radially outside, relative to the fixed part (5), defining a retention part. 12. Folding apparatus according to claim 11, characterised in thatit comprises programmable electronic means for monitoring and controlling the position and movement of the compacting member (24) and retaining member (19). 13. Folding apparatus according to any one of claims 1 to 12, characterised in thatthe table (3) is provided with grippers (50) adapted to move from a retracted position within the table (3) to a projecting position for gripping a folded bag part. 14. Folding apparatus according to any one of claims 1 to 13, characterised in thatit comprises a heating station (3B) in which heating means (103) for the bag are provided. 15. Foldmg apparatus according to claim 14, characterised in thatit comprises holding means (17) which are movable in the direction of a substantially vertical axis (ZZ) between a released position above the table (3) and a bearing position lower down, and the table (3) is capable of rotating about a substantially vertical axis, so as to take up at least two angular positions relative to said axis, one position corresponding to the position of the bag (1) in the heating station (3B) and the other position corresponding to the position of the fixed part (5) perpendicular to the holding means (17) and the compacting operations. 16. Folding apparatus according to any one of claims 1 to 15, charactensed in that the table (3) is provided with suction means (13) adapted to exert suction forces on the bag (1) tending to flatten it locally on the table (3). 17. Method of using an apparatus according to any one of claims 1 to 16 for carrying out the folding of an airbag for a safety device in a motor vehicle, wherein the empty bag (1) is placed spread out on a table (3), the bag (1) is held flat on the table (3) about a fixed part (5) by applying a holding force to said fixed part (5) of the bag, characterisedm that the following sequence of successive operations is then carried out: - a first elementary compacting operation in which the bag (1) is compacted by moving the compacting member (24, 25) towards the fixed part (5) in a first direction substantially parallel to the table (3) and perpendicular to the first batten (24A, 25A) of the compacting member (24, 25); - the bag part thus compacted is held by exerting substantially vertical pressure by means of a retaining member (19); - a second elementary compacting operation in which the bag (1) is compacted by moving the same compacting device (24, 25) towards the fixed part (5) m a direction substantially parallel to the table (3) and perpendicular to the second batten (24B, 25B) of the same compacting member; and - the bag part thus compacted is held by exerting substantially vertical pressure by means of a retaining member (19). 18. Method of using an apparatus according to claim 17, characterised in thattwo such sequences of operations are carried out consecutively and between the two sequences the compacting member (25) is displaced angularly relative to a substantially vertical axis (Z-Z) passing through the fixed part (5). 19. Method of using an apparatus according to claim 4, the process being m accordance with claim 17, characterised in thatthe following successive operations are carried out: - a first elementary compacting operation is carried out by means of a first batten (24A) of the first compacting member (24); - the first compacting member (24) is released into its inactive position so that it cannot interfere with the movement of the second compacting member (25); - a first elementary compacting operation is carried out using a first batten (25A) of the second compacting member (25), parallel to the first batten (24A) of the first compacting member (24); - a second elementary compacting operation is carried out using the second batten (25B) of the second compacting member (25); - the second compacting member (25) is released into its inactive position, so that it cannot interfere with the movement of the first compacting member (24), and the first compacting member (24) is moved into its active position; and - a second elementary compacting operation is carried out using the second batten (24B) of the first compacting member (24). 20. Folding method according to any one of claims 17 to 19, characterised in thatduring each elementary compacting operation, alternating pressures are exerted in a substantially vertical direction (Z-Z) on the part of the bag being compacted, so as to form folds. 21. Method of folding according to claim 20, characterised in thatsaid alternative pressures are exerted in at least two regions of the bag part being compacted, which are offset in the direction of movement parallel to the table. 22. Method of folding according to any one of claims 17 to 21, characterised in thatan underpressure is created between the bag (1) and the support table (3) by suction means (13). 23. Method of folding according to any one of claims 17 to 22, characterised in thata heating operation is carried out on the bag prior to the sequence of elementary operations.
