DIGITAL READ OUT INDICATOR FOR VEHICLES

• US 3,704,445 A
• Filed: 07/20/1971
• Issued: 11/28/1972
• Est. Priority Date: 07/20/1971
• Status: Expired due to Term

• Current Assignee: Richard R. Lanham
• Original Assignee: Richard R. Lanham
• Inventors: Lanham, Richard R.
• Primary Examiner(s): Waring, Alvin H.
• Application Number:
  US05/164,294
• Time in Patent Office: 497 Days
• Field of Search: 340/52,53,62,263,264
• US Class Current: 340/441
• CPC Class Codes: G01P 1/10 for indicating predetermined speeds
• CPC Class Codes: G01P 3/489 Digital circuits therefor

Abstract

Apparatus disposed in a vehicle for providing a digital read out indicator for displaying vehicular speed or engine revolutions comprising a mechanical shaft rotated at a speed corresponding to the vehicular speed or engine revolutions, means responsive to the shaft rotation to produce an electrical pulse train at a recurrence frequency proportional to the shaft rotational speed, and digital display means responsive to said pulse train to produce the desired display.

Claims

1. In a vehicle having a shaft which turns at a speed designating the revolutions per unit time of the engine or the speed of the vehicle, in combination:

first means responsive to the shaft rotation to produce a synchronized electrical pulse train having a variable recurrence frequency equal to the speed of the shaft;

a digital display device replacing the vehicle speedometer; and

second means including a plurality of decimal counting units coupled between said first means and said device to cause said device to produce a visual digital reading of the exact engine speed or the vehicular speed.

2. A vehicle as set forth in claim 1 having an additional combination of first means, second means and device whereby one device displays engine speed and the other device displays vehicular speed.

3. A vehicle as set forth in claim 1 wherein the second means includes a plurality of decimal indicating thumb limit switches.

4. A vehicle as set forth in claim 3 wherein the second means includes a limit lamp logic circuitry.

5. A vehicle as set forth in claim 1, wherein said first means includes means responsive to the shaft rotation to produce an electrical pulse train having a variable recurrence frequency proportional to the speed of the shaft;

a clock oscillator and gating circuitry receiving said proportional pulse train and the output from said clock oscillator and producing said synchronized pulse train.