Revolving door with security locking mechanism

Claim 1

In a revolving door assembly comprising a generally cylindrical, vertically extending door housing, said door housing defining diametrically opposed vertically extending openings therein, a vertically mounted door comprising a central axis and at least two radially extending door leaves connected thereto, said door leaves adapted for rotation about said axis, and a canopy mounted above said door in overlapping relation to said door housing, said canopy containing means for controlling and arresting the movement of said door comprising a linearly elongated radiant energy emitting device adapted to provide a generally rectangular, planar energy field, said field of equal displacement to one of said leaves and extending in the vertical plane, said energy emitting device mounted in radial relation to the axis of said revolving door whereby said energy field abuts at one end thereof with said axis and at the opposite end thereof with a vertical edge of one of said openings, said energy emitting device adapted upon the interruption of any portion of said energy field by a foreign object to actuate the locking of said revolving door in fixed position, whereby passage of man or objects is prevented, wherein said door leaves define upper horizontal edges passing adjacent said canopy, said upper horizontal edges provided with surfaces reflective to said energy field whereby the interruption of said field during the passage therethrough of said leaves is prevented.