Speed reducer for retractable screen systems

  • US 6,854,505 B2
  • Filed: 07/11/2003
  • Issued: 02/15/2005
  • Est. Priority Date: 07/19/2001
  • Status: Expired due to Fees
First Claim
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1. A speed reducer for use in a retractable screen system having an elongated axle extending between a pair of opposing end caps with at least a portion of the axle being coupled to one side of a retractable screen, the axle being biased to a retracted position and operable to wind the screen onto the axle'"'"'s circumference to a retracted position or unwind so the screen may be extended, said speed reducer comprising:

  • a hollow cylindrical housing defining a speed control chamber and having a closed end and an opposing end with a central aperture, said housing further including an outer surface for coupling to a first end of said axle and an inner surface with a plurality of inwardly projecting rib elements;

    an elongated shaft rotatably engaged with said housing, said shaft including one end projecting through said central aperture for engaging an end cap proximate the first end of the axle to fix rotation of said shaft and a plurality of outwardly extending rib elements inserted into said speed control chamber, said shaft being smaller in diameter than said inner surface of said housing to form a fluid receiving gap; and

    a braking fluid at least partially filling in said fluid receiving gap and in fluid communication with said inwardly and outwardly projecting rib elements, said braking fluid inhibiting free rotation of said housing relative to said shaft whereby said one end of said shaft may be connected to the end cap proximate the first end of the axle and said housing coupled to said axle to control the winding speed of the screen as the axle turns relative to said shaft.

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