Cantilevered deflection sensing system

• US 6,236,301 B1
• Filed: 09/04/1996
• Issued: 05/22/2001
• Est. Priority Date: 09/04/1996
• Status: Expired due to Term

• Current Assignee: Sensitron
• Original Assignee: Sensitron
• Inventors: Putnam, Greg A., Langford, Gordon B., Montano, Cesar A.
• Primary Examiner(s): Easthom, Karl D.
• Application Number:
  US08/707,406
• Time in Patent Office: 1,721 Days
• Field of Search: 338/2, 338/6, 338/47, 338/50, 338/99, 338/114, 338/209, 338/210, 338/211, 338/260, 338/320, 738/624.74, 738/626.27, 738/626.34
• US Class Current: 338/6
• CPC Class Codes: B60Q 5/003 mounted on the steering wheel
• CPC Class Codes: B60R 21/21658 with integrated switches, e.g. horn switches
• CPC Class Codes: G01B 7/18 using change in resistance
• CPC Class Codes: H01C 10/10 adjustable by mechanical pressure or force

Abstract

A deflection sensing system for detecting deflection includes one or more deflection sensors between opposing sets of extensions. When one set of extensions is moved toward an opposing set of extensions, the deflection sensors are deflected. A preferred deflection sensor is a flexible potentiometer, which has a resistance that changes as the flexible potentiometer is deflected A flexible potentiometer includes a variable resistance material on a substrate. In a preferred system, the flexible potentiometer includes a cantilevered section, which is deflected about an extension with respect to the remainder of the flexible potentiometer, or with respect to a portion of the substrate not including the variable resistance material. A flexible potentiometer experiences less stress when in cantilevered form than when stretched between two extensions. In either case, the extensions may be joined to first and second corrugated plates. A particular application for the system is in a horn activator used in connection with an automobile air bag system. A corrugated plate may be adhered to the inside of a hub cover. Alternatively, the extensions may be adhered directly to the hub cover. Analyzing circuitry senses the resistance of a resistive grid including flexible potentiometers. The analyzing circuitry interprets a change in resistance to mean there has been a deflection. The analyzing circuitry may consider merely that there has been a change in resistance, or it may consider the amount of change in resistance. The analyzing circuitry may essentially simultaneously analyze the resistance of more than one resistive grid or deflection sensor.

Claims

1. A horn activation system for use in a vehicle having a steering wheel, a horn, and an inflatable air bag associated with the steering wheel, the horn activation system comprising:

a first substrate having a surface with a plurality of first extensions formed to extend away therefrom, each of said first extensions having a first contact surface spaced away from the surface of said first substrate to form a first space adjacent to each of said first extensions;

a second substrate having a surface with a plurality of second extensions formed therewith to extend away therefrom, each of said second extensions having a second contact surface spaced away from the surface of said second substrate and at least one of said second contact surfaces being positioned to register with and enter said first space associated with one of said first extensions upon movement of said second substrate toward said first substrate;

a steering wheel having a steering wheel hub cover and an air bag attached proximate said steering wheel hub cover, said steering wheel hub cover being deflectable by a user between an at-rest position and an active position with one of said first substrate and said second substrate being affixed to said steering wheel hub cover to be deflectable therewith to move relative to the other of said first substrate and said second substrate;

a third substrate which includes a resistive grid for positioning between said first substrate and said second substrate, said resistive grid being comprised of a plurality of flexible potentiometers electrically connected together, each flexible potentiometer of said plurality of flexible potentiometers with one fixed end formed with said third substrate and one free end extending away therefrom and each flexible potentiometer of said plurality of flexible potentiometers having a first portion between said fixed end and said free end to register with said first contact surface of one of said first extensions and a second portion between said first portion and said free end which second portion is cantilevered to extend away from said first portion to register with said first space proximate said first extension for deflection toward and away from said first space to vary the resistance of said flexible potentiometer upon movement of said steering wheel hub cover between said at-rest position and said active position, each of said flexible potentiometers being of the type having an electrical resistance that predictably changes upon deflection thereof;

activation circuitry conductively connected to said horn to activate the horn when the activation circuitry receives an activation signal; and

analyzing circuitry conductively connected to said resistive grid and to the activation circuitry, said analyzing circuitry generating and supplying the activation signal to the activation circuitry in response to the change in resistance of the resistive grid upon movement between the said at-rest position and the said active position.

2. The system of claim 1, wherein said plurality of first extensions with said first substrate are formed with a corrugated plate which is adhered to said steering wheel hub cover.

3. The system of claim 1, further comprising an additional resistive grid that is connected to aid analyzing circuitry, and wherein said analyzing circuitry produces said activation signal in response to the change in resistance of the additional resistive grid.

4. The system of claim 1, wherein the said resistive grid is deflectable in two directions.

5. The system of claim 1, wherein a flexible potentiometer is deflectable in two directions, and wherein said potentiometer experiences a change of resistance in response to deflection in different directions from an at-rest position.

6. A horn control activation system for use in a vehicle having an air bag attached to a steering wheel and having a horn, the horn control system comprising:

a first substrate having a surface with a plurality of first extensions formed therewith to extend away therefrom, each of said first extensions having a first contact surface spaced away from the surface of said first substrate to form a first space adjacent to each of said first extensions;

a second substrate having a surface with a plurality of second extensions having a second contact surface spaced away from the surface of said second substrate and at least one of said second contact surfaces being positioned to register with said first space associated with one of said first extensions upon movement of said first substrate toward said second substrate;

a steering wheel of a vehicle having a steering wheel hub cover and an air bag attached proximate said steering wheel hub cover, said steering wheel hub cover being deflectable by a user between an at-rest position and an active position with one of said first substrate and said second substrate being affixed to said steering wheel hub cover to be deflectable therewith to move relative to the other of said first substrate and said second substrate;

a third substrate positioned between a first extension of said first substrate and a second extension of said second substrate;

a plurality of deflection sensors formed on a third substrate, each of said plurality of deflection sensors being of the type which change electrical resistance upon deflection thereof, each of said deflection sensors including a cantilevered section positioned to extend into a said first space proximate one of said first extensions, said cantilevered section having a first end which is non movable relative to one of said first extension and said second extension and one free end extending away from said first end, said free end of each said deflection sensor of said plurality of deflection sensors being deflectable by a said second extension sufficient to cause a change in resistance of said deflection sensor upon movement of said steering wheel hub cover from said at-rest position toward said active position;

activation circuitry conductively connected to said horn to activate said horn when said activation circuitry receives said activation signal; and

analyzing circuitry conductively connected to said plurality of deflection sensors and to the activation circuitry, said analyzing circuitry being operative to generate and supply said activation signal, to the activation circuitry in response to the change in resistance of said plurality of deflection sensors.

7. A horn control activation system for use in an automobile having an air bag adjacent to a steering wheel and having a horn, the horn control system comprising:

a first substrate having a surface with a plurality of first extensions formed therewith to extend away therefrom, each of said first extensions having a first contact surface spaced away from the surface of said first substrate to form a first space adjacent to each of said first extensions;

a second substrate having a surface with a plurality of second extensions formed therewith to extend away therefrom, each of said second extensions having a second contact surface spaced away from the surface of said second substrate and at least one of said second contact surfaces being positioned to register with said first space associated with one of said first extensions upon movement of said first substrate toward said second substrate;

a steering wheel of a vehicle having a steering wheel hub cover and an air bag attached proximate said steering wheel hub cover, said steering wheel hub cover being deflectable by a user between an at-rest position and an active position with one of said first substrate and said second substrate being affixed to said steering wheel hub cover to be deflectable therewith to move relative to the other of said first substrate and said second substrate;

a third substrate which includes a resistive grid having a plurality of deflection sensors on said third substrate, each deflection sensor having a first end which is non movable relative to one of said first extension and said second extension and a cantilevered section with a fee end extending away from said first end, said free end respectively being registerable with said first space of an extension of said first substrate, each of said cantilevered sections of said plurality of deflection sensors being deflected by at least one of the said second extensions to cause a change in resistance of the resistive grid upon movement of said first substrate relative to said second substrate;

activation circuitry conductively connected to said horn to activate the horn when the activation circuitry receives an activation signal; and

analyzing circuitry conductively connected to said plurality of deflection sensors and to the activation circuitry, the analyzing circuitry generating and supplying the activation signal to the activation circuitry in response to the change in resistance of the resistive grid.

8. A horn activation system for use in a vehicle having a steering wheel, a horn, and an inflatable air bag attached to the steering wheel, the horn activation system comprising:

a first substrate having a surface with a plurality of first extensions formed to extend away therefrom, each of said first extensions having a first contact surface spaced away from the surface of said first substrate to form a first space adjacent to each of said first extensions;

a second substrate having a surface with a plurality of second extensions formed therewith to extend away therefrom, each of said second extensions having a second contact surface spaced away from the surface of said second substrate and at least one of said second contact surfaces being positioned to register with and enter said first space associated with one of said first extensions upon movement of said second substrate toward said first substrate;

a steering wheel having a steering wheel hub cover and an air bag attached proximate said steering wheel hub cover, said steering wheel hub cover being deflectable by a user between an at-rest position and an active position with one of said first substrate and said second substrate being affixed to said steering wheel hub cover to be deflectable therewith to move relative to the other of said first substrate and said second substrate;

a third substrate which includes a resistive grid for positioning between said first substrate and said second substrate, said resistive grid having a plurality of flexible potentiometers electrically connected together, each flexible potentiometer of said plurality of flexible potentiometers having a first portion with a first end which is non movable relative to one of said first extensions and positioned to register with said first contact surface of one of said first extensions, and each of said plurality of flexible potentiometers having a second portion with a free end, said second portion of each of said flexible potentiometers being cantilevered with its free end extending away from said first end into a respective said first space proximate said first extension for deflection by a said second extension toward and away from said first space for varying the resistance of each of said plurality of flexible potentiometers upon movement of said steering wheel hub cover between said at-rest position and said active position;

activation circuitry conductively connected to said horn to activate the horn when the activation circuitry receives an activation signal; and

analyzing circuitry conductively connected to said resistive grid and to the activation circuitry, said analyzing circuitry generating and supplying the activation signal to the activation circuitry in response to the change in resistance of the resistive grid upon movement of said steering wheel hub cover between the said at-rest position and the said active position.

9. A horn activation system for use in a vehicle having a steering wheel, a horn, and an, inflatable air bag associated with the steering wheel, the horn activation system comprising:

a first substrate having a surface with a plurality of first extensions formed to extend away therefrom, each of said first extensions having a first contact surface spaced away from the surface of said first substrate to form a first space adjacent to each of said first extensions;

a second substrate having a surface with a plurality of second extensions formed therewith to extend away therefrom, each of said second extensions having a second contact surface spaced away from the surface of said second substrate and at least one of said second contact surfaces being positioned to register with and enter said first space associated with one of said first extensions upon movement of said second substrate toward said first substrate;

a steering wheel having a steering wheel hub cover with an air bag attached proximate said steering wheel hub cover, said steering wheel hub cover being deflectable by a user between an at-rest position and an active position with one of said first substrate and said second substrate being affixed to said steering wheel hub cover to be deflectable therewith to move relative to the other of said first substrate and said second substrate;

a third substrate positioned between a first extension of said first substrate and second extension of said second substrate;

a plurality of flexible potentiometers each formed on said third substrate for positioning between said first substrate and said second substrate, said plurality of flexible potentiometers being electrically connected together, each flexible potentiometer of said plurality of flexible potentiometers having a first portion which is non moveable relative to said first contact surface and positioned to register with said first contact surface of one of said first extensions, and each of said plurality of flexible potentiometers having a second portion with a free end, said free end of each of said flexible potentiometers being free and cantilevered with said free end extending away from said first portion into a respective said first space proximate said first extension for deflection by a said second extension toward and away from said first space for varying the electrical resistance of each of said plurality of flexible potentiometers upon movement of said steering wheel hub cover between said at-rest position and said active position;

activation circuitry conductively connected to said horn to activate the horn when the activation circuitry receives an activation signal; and

analyzing circuitry conductively connected to said plurality of flexible potentiometers and to the activation circuitry, said analyzing circuitry generating and supplying the activation signal to the activation circuitry in response to the change in resistance of a flexible potentiometer of said plurality of flexible potentiometers upon movement of said steering wheel hub cover between the said at-rest position and the said active position.

10. The horn activation system of claim 9 wherein said plurality of flexible potentiometers are connected in electrical series.