×

Rolling fire door

  • US 5,022,452 A
  • Filed: 12/08/1989
  • Issued: 06/11/1991
  • Est. Priority Date: 12/08/1989
  • Status: Expired due to Fees
First Claim
Patent Images

1. A rolling fire door, comprising:

  • a curtain of a plurality of interconnected slats;

    a pair of tracks receiving said curtain along lateral edges thereof;

    a tube traversing said pair of tracks at a top end thereof and interconnected to said curtain, rotation of said tube in a first direction raising said curtain in said pair of tracks, and rotation of said tube in a second direction allowing said curtain to be lowered in said pair of tracks; and

    control means, comprising a hydraulic pump connected to and driven by said tube for restricting and regulating a rate of descent of said curtain within said pair of tracks under its own weight and a flow control valve interposed in a flow path of said hydraulic pump, said flow control valve restricting flow through said flow path and thereby providing a load on said hydraulic pump and restricting rotation of said tube, said control means being adjustable to regulate said load, and further comprising a bypass valve within said flow path, said bypass valve being in shunt with said flow control valve, said hydraulic pump becoming free wheeling upon actuation of said bypass valve.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×