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Dental chair

  • US 4,456,297 A
  • Filed: 05/18/1981
  • Issued: 06/26/1984
  • Est. Priority Date: 05/16/1980
  • Status: Expired due to Fees
First Claim
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1. A dental chair including a seat, a backrest and mechanism pivotally connecting the backrest to the seat comprising:

  • (a) a first link having a first end jouraled to said seat;

    (b) a second link having a first end journaled to said backrest, said links crossing and being pivotally connected intermediate their ends to form a scissor linkage;

    (c) a rocker arm connecting the second end of said first link to said backrest to permit arcuate displacement of the second end of said first link relative to said backrest;

    (d) a crank arm connecting the second end of said second link to said seat to effect arcuate displacement of the second end of said second link relative to said seat;

    (e) said mechanism being operative when said crank arm is moved in the direction away from said backrest to pivot said backrest downwardly, and concurrently said scissor linkage being operative to move the first end of said second link toward the first end of said first link.

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