Patent ID: 6164788
Filing Date: 2000-12-26
Classification: F21S,F21V

Abstract:
A drop down concealed emergency lighting unit comprising:(a) a housing for substantially flush mounting in a recess formed in a building surface, said housing providing an opening extending in a plane to be oriented adjacent and parallel to the building surface;(b) a door for closing said opening;(c) means pivotally mounting one end of said door on said housing for movement relative thereto between a first closed position overlying said opening and second open position in which said door extends substantially perpendicularly to said plane of said opening;(d) a drive assembly for moving said door between said open position and said closed position including:(i) a direct current drive motor mounted on said housing and having an output shaft;(ii) a drive gear mounted on said output shaft;(iii) a driven gear mounted on said door; and(iv) means operatively engaging said drive and driven gears for movement of said door to the closed position and for maintaining said door in said closed position;(e) a lamp unit powered by direct current; and(f) an electrical control circuit adapted to be connected to sources of alternating current and of direct current and connected to said motor and said lamp unit, said circuit including a rectifier to convert alternating current to direct current for supply to said motor, said control circuit including means for sensing the absence of alternating current and effecting disengagement of said gear operatively engaging means, to allow said door to move from said closed position to said open position, said circuit also providing power to said lamp unit upon such absence of alternating current and movement of said door to said open position, said circuit include means for sensing the restoration of alternating current and acting to effect reengagement of said gear operatively engaging means and to supply direct current to said motor to move said door to said closed position, said control circuit further acting to terminate flow of direct current to said lamp upon movement of said door to said closed position.