Sensing system for sensing state of wear of seatbelt

• US 3,898,473 A
• Filed: 11/06/1973
• Issued: 08/05/1975
• Est. Priority Date: 12/18/1972
• Status: Expired due to Term

• Current Assignee: Atsushi Ueda, Kosaku Uota, Mitsuaki Ishii
• Original Assignee: Atsushi Ueda, Kosaku Uota, Mitsuaki Ishii
• Inventors: Ueda, Atsushi, Uota, Kosaku, Ishii, Mitsuaki
• Primary Examiner(s): Schaefer, Robert K.
• Assistant Examiner(s): Ginsburg, M.
• Application Number:
  US05/413,200
• Time in Patent Office: 637 Days
• Field of Search: 307/1SB 180/82C 340/52E 200/61.58B
• US Class Current: 180/270
• CPC Class Codes: B60R 2022/4816 for sensing locking of buckle
• CPC Class Codes: B60R 2022/4858 for sensing pressure on seat
• CPC Class Codes: B60R 2022/4891 preventing use of the vehicle when the seatbelt is not fastened
• CPC Class Codes: B60R 22/48 Control systems, alarms, or interlock systems, for the correct application of the belt or harness

Abstract

The disclosed system for a motor vehicle comprises a seat switch adapted to be closed when a person sits on a seat, a belt switch adapted to be closed when the person wears a seatbelt and a FLIPFLOP circuit including two NAND gates having two inputs connected to both switches respectively. Another NAND gate receives inputs from both the FLIP-FLOP circuit and the belt switch responds to the closure of the seat switch followed by the closure of the belt switch to provide an output to permit the associated engine to start.

Claims

1. A sensor system for sensing a state of wear of a seat belt comprising, in combination, a first normally open seat switch adapted to be closed when sat on by a vehicle occupant, a second normally open switch adapted to be closed by the fastening of a seat belt, a FLIP-FLOP circuit including a pair of input terminals operatively coupled to said first and second switches respectively and an output, said FLIP-FLOP circuit being operated in response to the operation of either of said first and second switches, a time delay circuit interposed between one input to said FLIP-FLOP circuit and said first switch, a first gate circuit including a pair of inputs connected to the output of said FLIP-FLOP circuit and said second switch, respectively, and additional means are provided including a transistor operatively connected to said first gate circuit and responsive to an output signal from said first gate circuit, a starter relay including a winding connected to said transistor and a set of contacts connected to both a key operating switch and a starter winding, said set of contacts adapted to be open when said first switch is closed while said second switch is open, as well as when said second switch is closed followed by the closure of said first switch, thereby preventing operation of an associated engine and adapted to be closed when said second switch closes after said first switch closes, allowing activation of said engine, and means operatively coupled for preventing electric power from being supplied to said starter winding through said key operating switch once the associated engine is started.

2. A sensor system as claimed in claim 1 wherein said additional means further comprises a second gate circuit including an input connected to the output of said first gate circuit, and a first semiconductor diode including an anode electrode connected to the output of said second gate circuit and a cathode electrode connected to that input to said FLIP-FLOP circuit connected to said time delay circuit.

3. A sensor system as claimed in claim 1 wherein said additional means further comprises a second gate circuit including an input connected to an ignition switch, a third gate circuit including a pair of inputs connected to the output of said first gate circuit and the output of said second gate circuit, respectively, and a semiconductor diode including an anode electrode connected to the output of said third gate circuit and a cathode electrode connected to that input to said FLIP-FLOP circuit connected to said time delay circuit.

4. A sensor system as claimed in claim 1 wherein said additional means further comprises a second semiconductor diode inclulding an anode electrode connected to said first switch, a third semiconductor diode including an anode electrode connected to an ignition switch, said second diode and said third diode including interconnected cathode electrodes and also being connected to a conductor to an electric source for said FLIP-FLOP circuit, and a parallel combination of a resistor and a capacitor, said parallel combination, said first gate circuit and said second gate circuit connected between said conductor to the electric source and ground.