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DISPLAY DEVICE

  • US 3,798,855 A
  • Filed: 09/15/1972
  • Issued: 03/26/1974
  • Est. Priority Date: 09/15/1972
  • Status: Expired due to Term
First Claim
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1. A display device adapted to be mounted underground, comprising a marker panel, means operatively connected with the marker panel for raising and lowering the same, counterweight means for effecting the operation of said raising and lowering means, and means for translating said counterweight means relative to said raising and lowering means thereby changing the direction of the action of said counterweight means.

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