Horn actuator incorporating a transducer in a steering wheel

• US 5,463,258 A
• Filed: 01/15/1993
• Issued: 10/31/1995
• Est. Priority Date: 04/29/1992
• Status: Expired due to Fees

• Current Assignee: Textron Inc
• Original Assignee: Davidson Textron Inc. (Textron Inc)
• Inventors: Filion, Scott M., Frost, Colin C., Yedlin, Vincent J., Roberge, Richard D., Moore, Denis L.
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): Elms, Richard T.
• Application Number:
  US08/005,314
• Time in Patent Office: 1,019 Days
• Field of Search: 307/9.1, 307/10.1, 307/116, 307/119, 361/170, 361/179, 340/384.7, 200/61.54, 200/61.55, 200/61.56, 200/511-517, 280/731, 280/728 A, 280/735
• US Class Current: 307/10.1
• CPC Class Codes: B60Q 5/003 mounted on the steering wheel
• CPC Class Codes: B60R 21/21658 with integrated switches, e.g. horn switches

Abstract

A steering wheel (12) incorporates an air bag unit (22). The air bag unit has a cover door (30) with a transducer (38) molded in a deformable front wall (35) of the cover door. The transducer can be a force sensitive resistor (38) which is operably connected to an electrical circuit (42) that actuates a horn (44) when the circuit senses a change in the resistance of force sensitive resistor (38). The force sensitive resistor (38) produces a suitable change in resistance when hand pressure is exerted on the front wall (35).

Claims

1. An apparatus for actuating an electrical device in response to pressure applied to a deformable air bag cover door, comprising:

an air bag cover door deformable by hand pressure;

a force sensitive resistor attached to said cover door such that its resistance changes upon pressure being exerted on the cover door; and

a switching circuit connected to said force sensitive resistor for changing said switching circuit'"'"'s conductive state in response to a change in the resistance of said force sensitive resistor, said switching circuit comprising a transistor switch controlled by said force sensitive resistor with said transistor switch having a first current carrying terminal for coupling said transistor switch to the electrical device, a second current carrying terminal coupled to a common ground, and a driving terminal coupled to said force sensitive resistor;

wherein said transistor switch is operable to provide a low impedance path from said first current carrying terminal to said second current carrying terminal when said force sensitive resistor undergoes a change in resistive value; and

wherein said switching circuit further comprises a resistive element having a first terminal coupled to said first current carrying terminal of said transistor switch and a second terminal for coupling said transistor switch to the electrical device, such that current flowing from the electrical device flows through said resistive element and said first current carrying terminal.