NAVIGATIONAL CHART DISPLAY DEVICE

• US 3,724,079 A
• Filed: 09/23/1970
• Issued: 04/03/1973
• Est. Priority Date: 09/23/1970
• Status: Expired due to Term

• Current Assignee: Mitchell Arthur Kapland, Robert E. Jasperson
• Original Assignee: Mitchell Arthur Kapland, Robert E. Jasperson
• Inventors: Jasperson, Robert E., Kapland, Mitchell Arthur
• Primary Examiner(s): Martin, Jr., William D.
• Application Number:
  US05/074,702
• Time in Patent Office: 923 Days
• Field of Search: 33/1SD 235/88 353/12
• US Class Current: 33/1.0SD
• CPC Class Codes: G01C 21/22 Plotting boards
• CPC Class Codes: G09B 29/005 Map projections or methods associated specifically therewith
• CPC Class Codes: G09B 29/10 Map spot or coordinate position indicators; Map reading aids optical projection apparatus per se G03B

Abstract

A navigational chart display device which is adapted to enable a pilot to fix his position, to plot courses and to measure distances. The device is constituted by a stationary board having printed within a circular zone on the face thereof a Mercator projection of a selected region, the zone being encircled by a true compass rose. Within the true compass rose and concentric therewith is a magnetic variation rose. Superposed on the chart board is a transparent writing panel, and sandwiched therebetween is a transparent disc which is pivotally mounted for rotation about the zone center of the chart. The disc is provided with orthagonally-crossed diameter lines ruled thereon, which lines terminate in pointers and are adapted to indicate angular positions with respect to the true compass rose, the disc also having an array of equi-spaced grid lines ruled thereon in parallel relation to one of the diameter lines. The grid lines on the rotatable disc serve to plot bearings, lay off courses, plot latitude and longitude coordinates and to measure distances, these procedures being carried out by drawing erasable lines on the writing board.

Claims

1. A chart display device enabling a navigator to fix his position, to plot courses and to measure distances, the device comprising:

A. a stationary board having printed thereon within a circular central zone a Mercator projection of a selected region to be navigated, the zone being encircled by a true compass rose hav concentrically disposed therein a magnetic variation rose, said board having a longitude scale and a latitude scale along respective edges thereof;

B. a transparent stationary writing panel superposed on said board and having matching dimensions, said panel being formed of a plastic material which accepts the erasable writing of a grease pencil, and C. a manually rotatable transparent disc interposed between said board and said panel and pivoted for rotation about the center of said zone, said disc having parallel lines ruled thereon to define a grid and having two orthagonally-crossed diameter lines terminating in pointers which adjoin the scale of said compass rose.

2. A device as set forth in claim 1, including removable means to pivot said disc to said board whereby said board may be replaced by a second board containing another chart.

3. A device as set forth in claim 2, wherein said board contains a chart on the opposite face thereof and is reversible with respect to said disc.