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Adjustable magnetic compass

  • US 5,528,837 A
  • Filed: 10/02/1995
  • Issued: 06/25/1996
  • Est. Priority Date: 03/16/1993
  • Status: Expired due to Term
First Claim
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1. An adjustable magnetic compass for adjustably compensating for the magnetic variation between magnetic north and map north, the adjustable magnetic compass comprising:

  • a geographic chart visually identifying a plurality of specific geographic regions, each geographic region containing a unique indicia therewithin specifying a required amount of adjustment to be made when the adjustable magnetic compass is physically within the geographic region;

    a housing for operatively encasing a compass dial wherein the compass dial includes a plurality of indicia representative of directional positioning of the adjustable magnetic compass;

    a lubber line operatively associated with the housing for visual referencing relative to the indicia on the compass dial in order to indicate the directional positioning of the adjustable magnetic compass;

    means for adjusting the lubber line relative to the indicia on the compass dial, to, in turn, visually compensate for the magnetic variation between magnetic north and map north relative to the physical geographic location of the adjustable magnetic compass; and

    means for identifying that an appropriate amount of adjustment to the lubber line has been accomplished, the identifying means comprising a plurality of projections fixedly attached to the housing and referenced relative to the lubber line, wherein each of the projections are representative of a corresponding one of the unique indicia associated with the particular geographic region on the geographic chart and, accordingly, the geographic region where the adjustable magnetic compass is physically located.

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