Communications: electrical – Land vehicle alarms or indicators – Of collision or contact with external object
Reexamination Certificate
2000-06-05
2001-12-11
Swarthout, Brent A. (Department: 2632)
Communications: electrical
Land vehicle alarms or indicators
Of collision or contact with external object
C180S282000, C280S735000, C340S438000, C701S045000
Reexamination Certificate
active
06329911
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to arrangements for actuating airbags which include an airbag control unit, an actuating switch for activating and deactivating the airbag, and a visual display device.
Motor vehicles are increasingly being provided with airbags which expand in the event of a collision to protect the driver or passenger against an impact with hard parts of the vehicle structure. However, the airbag should be capable of being switched off, first so that it will not be released when a passenger seat is unoccupied, and second in order not to injure the driver or passenger in certain situations, for example when a child seat is placed on the passenger seat.
For this purpose, a mechanical switch is inserted in the circuit between the control unit and the airbag by which the airbag control unit can be electrically separated from the airbag. Such a switch is disclosed for example in U.S. Pat. No. 5,641,952. Simultaneously with the electrical separation, a visual display, for example in LED form, is energized so that the deactivation of the airbag is visually indicated. The electrical separation caused by actuation of the switch produces an open condition at the terminals of the airbag control unit and this might cause a malfunction since the airbag control unit cannot distinguish between an open condition due to a switching operation and a line interruption. Therefore, a safety resistor is inserted following the actuating switch in parallel with the airbag. This safety resistor has the same resistance value as the resistance of the firing pellet for the airbag. The actuating switch is arranged to complete the electric switch circuit either by way of the airbag or by way of the safety resistor so that the airbag control unit is always presented with the same resistive load.
Furthermore, there are conventional airbag control units that are electrically connected to the airbag in a permanent manner and have a visual display associated directly with the airbag control unit. In such arrangements, the airbag control unit is connected through two resistances in series to a source of operating voltage. The actuating switch is arranged in parallel with one of the resistances so that that resistance is short-circuited when the switch is closed. The resulting change in total resistance is detected by the airbag control unit by the corresponding change of current, causing the visual display to be turned on. A defect in the visual display device can also be detected by the airbag control unit by a change of current despite an unchanged electrical connection. In that case, the airbag control unit will not generate a firing signal for the airbag. However, this very advanced concept requires a completely redesigned airbag control unit so that considerable retrofitting would be required to meet the same safety standards in older motor vehicles.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to provide an airbag actuating arrangement which overcomes disadvantages of the prior art.
Another object of the invention is to provide an arrangement for actuating an airbag that results in improved safety but is capable of being added to conventional airbag control units.
These and other objects of the invention are attained by providing an airbag actuating arrangement having an intermediate electronics unit by which the airbag may be disconnected while presenting the same resistance to the control unit. In one embodiment, the intermediate electronics unit is arranged between the control unit and the airbag so that the intermediate electronics unit controls the electrical release or the airbag, i.e. converts a firing pulse from the airbag control unit when appropriate into an airbag igniter pulse or suppresses the firing pulse if the airbag is not activated. Since a visual display and an actuating switch are associated directly with the intermediate electronics unit, the intermediate electronics unit will detect a defect directly, for example because of a change in a test current. This defect signal is then transmitted to the airbag control unit which can indicate that fact to the motor vehicle operator or passenger.
With a parallel arrangement of the intermediate electronics unit and the airbag control unit, a firing pulse generated by the control unit is passed on to the airbag through the actuating switch. With this arrangement, a visual display is associated with the intermediate electronics unit and testable by that unit for functionality, whereas the actuating switch is tested using an error line and a test line. This ensures that any defect in the visual display device will be reliably detected. In another embodiment, a defect of the intermediate electronic unit will have no direct effect on the airbag which remains entirely ready for service.
By providing different identification resistances for the visual display device and/or the actuating switches, the components associated with the driver and passenger airbags can be identified by the intermediate electronics so that a possible mistake in installation can be recognized by the intermediate electronics unit and indicated to the airbag control unit. Preferably each identification resistance constitutes an integral unit with its associated airbag component thus avoiding any interchange of identification resistances at installation.
REFERENCES:
patent: 5069479 (1991-12-01), Koide et al.
patent: 5164901 (1992-11-01), Balckburn et al.
patent: 5324074 (1994-06-01), Christian et al.
patent: 5493270 (1996-02-01), Kondo
patent: 5544914 (1996-08-01), Borinski et al.
patent: 5641952 (1997-06-01), Collings
patent: 5915725 (1999-06-01), Schmid et al.
patent: 5977653 (1999-11-01), Schmid et al.
patent: 6016884 (2000-01-01), Swart et al.
patent: 6045156 (2000-04-01), Spell et al.
patent: 6181021 (2001-01-01), Zabler et al.
patent: 4237142 (1993-04-01), None
patent: 4426090 (1995-07-01), None
patent: 19545868 (1997-06-01), None
patent: 19628763 (1997-08-01), None
patent: 0719681 (1996-07-01), None
patent: 2289563 (1995-11-01), None
European Search Report No. EP 99 10 4270 dated Jan. 1, 2000.
Baker & Botts LLP
Swarthout Brent A.
Volkswagne AG
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