Passenger protecting apparatus
First Claim
1. A passenger protecting apparatus, comprising:
- a first circuit through which a first electric current flows, said first circuit including drive means for actuating a passenger-protecting element when an impact greater than a predetermined value is exerted on a vehicle;
a second circuit connected in parallel to said first circuit through which a second electric current flows, said second circuit including a dummy load, and said second electric current being substantially equal to said first electric current;
a firing switch means connected to a junction between said first circuit and said second circuit, said firing switch means being closed by a firing signal supplied thereto; and
diagnosing means for diagnosing said firing switch, said diagnosing means causing said second electric current to flow through said firing switch and said second circuit such that said diagnosing means monitors a voltage across said firing switch to determine whether said firing switch is closed normally by said firing signal.
1 Assignment
0 Petitions
Accused Products
Abstract
A passenger protecting apparatus has a parallel connection of two current paths; a dummy firing current path having a dummy load and a first switch connected in series, and a firing current path having a driving device and at least one impact-sensitive switch as a second switch connected in series. A third switch in series with the aforementioned parallel circuit is closed when the third switch receives a signal indicative of an impact from a signal processing circuit. The impact-sensitive switch, mounted on the vehicle body, is closed when an impact greater than a predetermined value is exerted to the vehicle. When the vehicle has an impact exerted thereto, a diagnostic circuit directs the signal indicative of the impact to the third switch, which closes to allow the firing current to flow through the firing current path. The firing current causes the driving device to activate the passenger-protecting element. When diagnosing the third switch, the diagnosis circuit causes the first switch to close and outputs a signal indicative of an impact to the third switch through the signal processing circuit. A dummy firing current flows in the dummy firing current path through the third switch. The dummy load has a resistance substantially equal to that of the driving device, allowing the diagnostic circuit to monitor the voltage across the third switch to check the switch operation of the third switch with a dummy firing current substantially equal to the actual firing current.
22 Citations
32 Claims
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1. A passenger protecting apparatus, comprising:
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a first circuit through which a first electric current flows, said first circuit including drive means for actuating a passenger-protecting element when an impact greater than a predetermined value is exerted on a vehicle; a second circuit connected in parallel to said first circuit through which a second electric current flows, said second circuit including a dummy load, and said second electric current being substantially equal to said first electric current; a firing switch means connected to a junction between said first circuit and said second circuit, said firing switch means being closed by a firing signal supplied thereto; and diagnosing means for diagnosing said firing switch, said diagnosing means causing said second electric current to flow through said firing switch and said second circuit such that said diagnosing means monitors a voltage across said firing switch to determine whether said firing switch is closed normally by said firing signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A passenger protecting apparatus for use with a vehicle comprising:
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drive means, said drive means actuating a passenger-protecting element when a first current flows therethrough; at least one mechanical switch in series with said drive means and closed in response to an impact exerted on the vehicle; a firing switch in series with said drive means, said firing switch being closed by a firing signal supplied thereto; a monitor resistor in parallel with said mechanical switch; an acceleration sensor operably connected to said firing switch; diagnosing means for diagnosing said firing switch, said diagnosing means supplying a signal to said firing switch to allow a second current through said monitor resistor, drive means, and said firing switch when said impact is not detected such that said diagnosing means monitors a voltage across said firing switch to determine whether said firing switch is functioning normally; and switching means for selectively connecting either one of said acceleration sensor or said diagnosing means to said firing switch.
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10. An actuating circuit, actuating a safety device upon determining an impact upon a vehicle, the actuating circuit comprising:
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a first series connection, including a heating element and an impact switch which closes upon sensing an impact; a second series connection, connected in parallel with said first series connection forming first and second nodes, the second series connection including a first electrical switch and a resistor; a second electrical switch connected to the first node formed by said first and second series connection; an acceleration sensor including an output operatively connected to an input of said second electrical switch; a diagnosis circuit, including a first output connected to a control input of the first electrical switch, controlling the opening and closing of the first electrical switch, a second output operatively connected to said input of said second electrical switch and an input of a signal from said first node, whereby the diagnosis circuit is able to close said first electrical switch and send a test signal to said second electrical switch in order to monitor at least one of said second series connection and said second electrical switch on the basis of said signal received from said first node. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. An actuating circuit, actuating a safety device upon determining an impact upon a vehicle, the actuating circuit comprising:
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an impact switch which closes in response to an impact; a resistor, connected in parallel to said impact switch forming a parallel connection; a heating element; an electrical switch, wherein said parallel connection, said heating element and said electrical switch are connected in series, forming a series connection; an acceleration sensor including an output operatively connected to an input of said electrical switch; a diagnosis circuit, including a first output operatively connected to said input of said electrical switch and further including a first input of a signal from a node of said series connection, whereby the test circuit is able to send a test signal to said electrical switch and monitor at least said electrical switch on the basis of a signal received from said node; and a selector for selectively connecting either one of said acceleration sensor or said diagnosis circuit to said electrical switch. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
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Specification