Patent ID: 6255791
Filing Date: 2001-07-03
Classification: E05F,E05Y,G01S

Abstract:
A method of automatically controlling the opening and closing of a door movable over a floor, and a drive for driving said door to its open and closed positions, said door having a predetermined approach area located in front of the door, a first predetermined lateral area laterally outwardly of the outer end of the door when in its closed position, and a second predetermined lateral area laterally inwardly of the inner end of the door when in its opened position; comprising the following operations:(a) ultrasonically monitoring said predetermined approach area located in front of said door for the entry of an object into said approach area and the movement of the object towards the closed door;(b) ultrasonically monitoring said first predetermined lateral area laterally outwardly of the outer end of the closed door, and second predetermined lateral area inwardly of the inner end of the open door, for the presence of an object in said predetermined lateral areas; and(c) controlling said drive in response to said monitoring operations.