Signal generator for a fluid-level indicator

• US 4,144,521 A
• Filed: 01/09/1978
• Issued: 03/13/1979
• Est. Priority Date: 01/15/1977
• Status: Expired due to Term

• Current Assignee: General Motors Corporation (General Motors Company)
• Original Assignee: General Motors Corporation (General Motors Company)
• Inventors: Lehnhert, Gunter
• Primary Examiner(s): Waring, Alvin H.
• Application Number:
  US05/867,708
• Time in Patent Office: 428 Days
• Field of Search: 340/59, 340/618, 340/623, 340/625, 116/109, 116/110
• US Class Current: 340/450.2
• CPC Class Codes: G01D 5/252 a combination of conductors or channels
• CPC Class Codes: G01F 23/36 using electrically actuated indicating means G01F23/38 takes precedence

Abstract

A signal generator for a fluid-level indicator in a motor vehicle which converts the pivotal movement of a pivot in the indicator produced by the rise and fall of a float in a fuel tank of the vehicle into digital binary coded electrical signals by means of digital binary coding means mechanically connected to said pivot, said digital binary coded signals being fed to an integrated switching circuit of the signal generator, the outputs from the switching circuit being enabled in sequence when, for example, the float rises from a minimum height in the fuel tank to a maximum height therein, each one of said outputs being connectable to a corresponding electrically-energizable light means, such as a luminous diode, associated with an illuminable display panel situated on an instrument panel of the vehicle. In a preferred embodiment of the invention, it is possible to transmit at least five separate digital binary coded signals from the digital binary coding means to the integrated switching circuit using a two-strand electrical connecting cable.

Claims

1. A signal generator for a fluid-level indicator in a motor vehicle to monitor the fuel level in a fuel tank of said vehicle, said vehicle including an instrument panel having mounted thereon an illuminable display device, said display device comprising a plurality of illuminable display panels, each of which carries a visible inscription and is illuminable by a respective electrically-energizable light means, said fluid-level indicator including float means suspended in the fuel of said fuel tank, lever transmission means connected to said float means, and a pivot connected to said lever transmission means in such a manner that movement of the float means in response to changes in the fuel level produces corresponding pivotal movement of said pivot, said signal generator comprising digital binary coding means mechanically connectable to said pivot so as to transform the pivotal movement thereof into corresponding digital binary coded signals, and an integrated switching circuit for receiving said corresponding digital binary coded signals as inputs thereto, said switching circuit having a plurality of outputs therefrom, each one of which is connectable to a respective one of said respective energizable light means, each one of said outputs being enabled in sequence by the serial changes in the digital binary coded signals produced by the pivotal movement of said pivot through a predetermined angle corresponding to the movement of the float means produced by the change in fuel level between a predetermined minimum level and a predetermined maximum level.

2. A signal generator for a fluid-level indicator in a motor vehicle to monitor the fuel level in a fuel tank of said vehicle, said vehicle including an instrument panel having mounted thereon an illuminable display device, said display device comprising a plurality of illuminable display panels, each of which carries a visible inscription and is illuminable by a respective electrically-energizable light means, said fluid-level indicator including float means suspended in the fuel of said fuel tank, lever transmission means connected to said float means, and a pivot connected to said lever transmission means in such a manner that movement of the float means in response to changes in the fuel level produces corresponding pivotal movement of said pivot, said signal generator comprising digital binary coding means connectable to said pivot so as to transform the pivotal movement thereof into corresponding digital binary coded signals, and an integrated switching circuit for receiving said corresponding digital binary coded signals as inputs thereto, said switching circuit having a plurality of outputs therefrom, each one of which is connectable to a respective one of said respective energizable light means, said digital binary coding means comprising an electrically non-conductive baseplate, two separate conductive tracks mounted on said baseplate and spaced radially from one another with respect to said pivot, and two contact members, each one of which is connectable mechanically to said pivot so that said pivotal movement of said pivot produces a corresponding arcuate movement of the contact member relative to said baseplate, and is maintained in sliding contact with predetermined portions of a respective one of said conductive tracks during said arcuate movement, the two contact members being arcuately movable through a predetermined angle which corresponds to the movement of the float means produced by a change in fuel level between a predetermined minimum level and a predetermined maximum level, said movement through the predetermined angle producing a series of digital binary coded signals at the inputs to the switching circuit that sequentially enables the plurality of outputs therefrom.

3. A signal generator for a fluid-level indicator in a motor vehicle to monitor the fuel level in a fuel tank of said vehicle, said vehicle including an instrument panel having mounted thereon an illuminable display device, said display device comprising a plurality of illuminable display panels, each of which carries a visible inscription and is illuminable by a respective electrically-energizable light means, said fluid-level indicator including float means suspended in the fuel of said fuel tank, lever transmission means connected to said float means, and a pivot connected to said lever transmission means in such a manner that movement of the float means in response to changes in the fuel level produces corresponding pivotal movement of said pivot, said signal generator comprising digital binary means connectable to said pivot so as to transform the pivotal movement thereof into corresponding digital binary coded signals, and an integrated switching circuit for receiving said corresponding digital binary coded signals as inputs thereto, said switching circuit having a plurality of outputs therefrom, each one of which is connectable to a respective one of said respective energizable light means, said digital binary coding means comprising an electrically non-conductive baseplate, two separate conductive tracks mounted on said baseplate and spaced radially from one another with respect to said pivot, and two contact members, each one of which is connectable mechanically to said pivot so that said pivotal movement of said pivot produces a corresponding arcuate movement of the contact member relative to the surface of the baseplate, the two contact members being arcuately movable through a predetermined angle which corresponds to the movement of the float means produced by an change in fuel level between a predetermined minimum level and a predetermined maximum level, the two conductive tracks being so arranged on the surface of the baseboard that each contact member comes into sliding contact with a respective one of said conductive tracks at least once during said arcuate movement and a series of at least four different digital binary coded signals is produced at the inputs to the switching circuit that sequentially enables the plurality of outputs therefrom.

4. A signal generator according to claim 3, in which each one of the conductive tracks includes a portion thereof which comes into sliding contact with the respective contact member during said arcuate movement and has a substantially higher electrical resistance than the remainder of the conductive track.

5. A signal generator for a fluid-level indicator in a motor vehicle to monitor the fuel level in a fuel tank of said vehicle, said vehicle including an instrument panel having mounted thereon an illuminable display device, said display device comprising a plurality of illuminable display panels, each of which carries a visible inscription and is illuminable by a respective electrically-energizable light means, said fluid-level indicator including float means suspended in the fuel of said fuel tank, lever transmission means connected to said float means, and a pivot connected to said lever transmission means in such a manner that movement of the float means in response to changes in the fuel level produces corresponding pivotal movement of said pivot, said signal generator comprising digital binary coding means connectable to said pivot so as to transform the pivotal movement thereof into corresponding digital binary coded signals, and an integrated switching circuit for receiving said corresponding digital binary coded signals as inputs thereto, said switching circuit having a plurality of outputs therefrom, each one of which is connectable to a respective one of said respective energizable light means, said digital binary coding means comprising an electrically non-conductive baseplate, two separate conductive tracks mounted on said baseplate and spaced radially from one another with respect to said pivot, and two contact members, each one of which is mounted adjacent one end of a respective arm, the other end of which is connectable to said pivot so that pivotal movement of said pivot produces a corresponding arcuate movement of the contact member relative to the surface of the baseplate, the two arms carrying the contact members being superimposed upon one another with the two contact members being spaced radially from one another with respect to said pivot, the two contact members being arcuately movable through a predetermined angle which corresponds to the movement of the float means produced by an change in fuel level between a predetermined minimum level and a predetermined maximum level, the two conductive tracks being so arranged on the surface of the baseboard that each contact member comes into sliding contact with a respective one of said conductive tracks at least one during said arcuate movement and a series of at least four different digital binary coded signals is produced at the inputs to the switching circuit that sequentially enables the plurality of outputs therefrom.