Patent ID: 6199617
Filing Date: 2001-03-13
Classification: E05F,E05Y

Abstract:
An apparatus for opening and closing a door opening with a bi-fold door hinged to a structure having the door opening, said bi-fold door having an upper panel, a lower panel, and hinges connecting the upper and lower panels to allow the panels to move from a vertically aligned closed position to a folded side-by-side open position comprising:door lift devices operable to selectively open and close the bi-fold door, reversible power means connected to the door lift devices for operating the door lift devices whereby the door lift devices are operable to open and close the bi-fold door, each of said door lift devices having a winch adapted to be mounted on the lower panel, said winch having a shaft, a cylindrical sleeve secured to the shaft, an elongated linear flexible web having a first end and a second end, and means connecting the first end of the web to the shaft, said shaft being connected to the reversible power means whereby the power means rotates the sleeve to wind the web in overlapping relation on the sleeve and unwind the web off the sleeve, and anchor means adapted to be mounted on the upper panel connected to the second end of the web whereby the power means rotates the sleeve to wind the web on the sleeve to open the bi-fold door and the power means rotates the sleeve to unwind the web off the sleeve to close the bi-fold door, said anchor means includes means to adjust the working length of the web to allow the door to move to the full open and closed positions, said means to adjust the working length of the web includes supports adapted to be secured to the upper panel, a member rotatably mounted on the supports, means connecting the second end of the web to the member whereby when the member is rotated the web is wound on the member to adjust the working length of the web, and means to hold the member in a fixed position relative to the supports to retain the web in its adjusted position.