Navigation instrument

• US 3,967,098 A
• Filed: 04/14/1975
• Issued: 06/29/1976
• Est. Priority Date: 04/14/1975
• Status: Expired due to Term

• Current Assignee: Gary L. Harnagel, Robert T. Longo
• Original Assignee: Gary L. Harnagel, Robert T. Longo
• Inventors: Longo, Robert T., Harnagel, Gary L.
• Primary Examiner(s): Morrison, Malcolm A.
• Assistant Examiner(s): Krass, Errol A.
• Application Number:
  US05/568,162
• Time in Patent Office: 442 Days
• Field of Search: 235/150.22, 235/150.27, 235/92 CP, 235/92 DP, 235/92 TC, 235/92 DN, 35/10.2, 35/12 N, 35/12 F, 35/12 B, 116/28, 116/29, 116/45, 340/23, 340/24, 340/27 NA, 343/112 C, 58/39.5, 58/74, 58/152 R, 58/152 E, 58/152 F
• US Class Current: 701/200
• CPC Class Codes: G01C 21/22 Plotting boards

Abstract

A digital navigation instrument primarily intended for the general aviation pilot. The navigation instrument combines the functions of a calculator and a stopwatch and provides a method of easy reference to a navigation chart. The resulting unit provides ease of data entry from the navigation chart and ease of alternation between time interval measurement and arithmetic calculations.

Claims

1. Navigation instrument comprising:

means for displaying a navigation chart;

a calculator circuit for performing arithmetic calculations, said calculator circuit including an output register;

display means for visually displaying a number in the output register of said calculator means;

means for manually entering data from the navigation chart to said calculator means;

means for manually entering operation signals to said calculator means;

an enabling signal, said enabling signal being manually activated;

clock means for providing a signal once each second; and

circuit means for entering data and operation signals to said calculator circuit in response to said enabling signal and the signal from said clock means, to add one to the number in the output register of said calculator circuit each second.

2. A navigation instrument as claimed in claim 1, which further comprises:

means for signaling when the two least significant whole number digits of the number in the output register of said calculator circuit are 59 and the number is positive and when the two least significant whole number digits of the number in the output register of said calculator circuit are 00 and the number is negative; and

means, responsive to said means for signaling, for adding 41 to the number in the output register of said calculator circuit.

3. A navigation instrument as claimed in claim 2, which further comprises:

means for displaying a decimal point to the left of the two least significant whole number digits in the output register of said calculator means.

4. A navigation instrument comprising:

means for visually displaying a navigation chart;

a calculator circuit for performing arithmetic calculations, said calculator circuit including an output register;

a visual display for displaying a number in the output register of said calculator circuit;

means for manually entering data from the navigation chart to said calculator circuit;

means for manually entering operation signals to said calculator circuit;

clock means for providing a signal once each second;

an enabling signal from a manual enabling switch;

circuit means, responding to said enabling signal and the signal from said clock means, for entering a data digit 1 signal and a plus/equal operation signal to said calculator circuit once each second, whereby one is added to the least significant whole number digit in the output register of said calculator circuit each second;

means for signaling when the two least significant whole number digits of the number in the output register of said calculator circuit are 59 and the number is positive and when the two least significant whole number digits of the number in the output register of said calculator circuit are 00 and the number is negative; and

means, responsive to said means for signaling, for entering a data digit 4 signal prior to the operation of said circuit means whereby 41 is added to the number in the output register of said calculator circuit each second.

5. A navigation instrument as claimed in claim 4, which further comprises:

means for displaying a decimal point to the left of the two least significant whole number digits in the output register of said calculator circuit.

6. A navigation instrument comprising:

a calculator circuit for performing arithmetic calculations, said calculator circuit including an output register;

a visual display for displaying a number in the output register of said calculator circuit;

means for manually entering data signals and operation signals to said calculator circuit;

clock means for providing a signal once each second;

an enabling signal from a manual enabling switch;

circuit means, responding to said enabling signal and the signal from said clock means, for entering a data digit 1 signal and a plus/equal operation signal to said calculator circuit once each second, whereby one is added to the least significant whole number digit in the output register of said calculator circuit each second;

means for signaling when the two least significant whole number digits of the number in the output register of said calculator circuit are 59 and the number is positive and when the two least significant whole number digits of the number in the output register of said calculator circuit are 00 and the number is negative; and

means, responsive to said means for signaling, for entering a data digit 4 signal prior to the operation of said circuit means whereby 41 is added to the number in the output register of said calculator circuit each second.

7. A navigation instrument as claimed in claim 6, which further comprises:

means for displaying a decimal point to the left of the two least significant whole number digits in the output register of said calculator circuit.