EMERGENCY LIGHT UNIT FOR MOUNTING TO AN ELECTRICAL WALL OUTLET

• US 3,739,226 A
• Filed: 09/08/1971
• Issued: 06/12/1973
• Est. Priority Date: 09/08/1971
• Status: Expired due to Term

• Current Assignee: Calvin J. Christensen, William A. Seiter
• Original Assignee: Calvin J. Christensen, William A. Seiter
• Inventors: Seiter, William A., Christensen, Calvin J.
• Primary Examiner(s): Kominski, John
• Application Number:
  US05/178,636
• Time in Patent Office: 643 Days
• Field of Search: 315/86,87,149-159 320/9,10 340/333 307/66 240/2S,2SP,10.6,1.6CH,37.1 174/53,54,55,56
• US Class Current: 315/86
• CPC Class Codes: F21S 9/022 Emergency lighting devices
• CPC Class Codes: F21V 23/0442 activated by means of a sensor, e.g. motion or photodetectors

Abstract

This invention relates to an emergency light unit of a size for plugging into a standard electrical wall outlet. The unit is self-contained and includes means for energizing the light when the main electrical power fails and the ambient light in the area in which it is mounted is below a prescribed level. The light is powered during emergency conditions from rechargeable batteries which are continuously and automatically charged when the main power is operational. All of the components of the unit, including the batteries, are mounted in a casing of unitary construction at the front of which are exposed light bulbs for supplying the emergency light, the light-sensitive surface of a photocell for sensing the ambient light level in the area, and an electrical utility outlet. Means accessible from the front of the unit are also provided for testing its operability. The unit is plugged into a standard electrical wall outlet with the cover plate removed and is secured in the same manner as a conventional cover plate.

Claims

1. A combination emergency light unit and wall plate for mounting to a standard electrical wall outlet of a building, the outlet having a plurality of electrical receptacles and being supplied with main power from the building, the unit comprising a casing covering the areas between the electrical receptacles and the surrounding wall so as to provide an attractive finishing plate for the outlet, a lamp means for supplying the emergency light, means for mechanically mounting the lamp means so that its light emanates from the front of the casing, electrical circuit means housed within the casing, plug terminals electrically and mechanically connected to the electrical circuit means and extending rearwardly of the casing, the plug terminals being adapted to plug into one of the electrical receptacles to supply main power to the unit, said casing having an opening in front of at least one of the other receptacles for accessibility for other use, emergency power supply means mounted in the casing, means associated with the electrical circuit means for sensing a power failure in the main power supply of the building, means for supplying electrical power from the emergency power supply means to the lamp means when a main power failure is sensed, thereby energizing the lamp means, whereby the emergency light unit plugs into an electrical receptacle of a standard electrical wall outlet for ease in assembly, provides a cover plate for the outlet, and provides accessibility to another receptacle of the outlet for use as desired.

2. The emergency light unit of claim 1 including photosensitive means for detectinG the ambient light level in the immediate area outside the unit, and means associated with the electrical circuit means and responsive to the photosensitive means for supplying power from the emergency power supply means to the lamp means only when the light in the room is below a prescribed level.

3. The emergency light unit of claim 2 wherein the emergency power supply means includes rechargeable batteries, and including means associated with the electrical circuit means for charging the batteries whenever the main power is on.

4. The emergency light unit of claim 1 wherein the casing defines cavities around the opening, and wherein the emergency power supply means includes rechargeable batteries mounted in said cavities.

5. The emergency light unit of claim 4 wherein the cavities for the batteries are located at the sides and end of the casing around the opening.

6. The emergency light unit of claim 1 including switch means mounted in the wall of the casing and actuatable from outside the unit, and means associated with the electrical circuit means and responsive to actuation of the switch means for testing the operability of the unit.

7. The emergency light unit of claim 6 wherein the actuation of the switch means simulates a power failure, thereby causing the lamps to light if the unit is operational.

8. The emergency light unit of claim 6 wherein the switch means is actuated by axial movement of a spring bias rod, the rod being reciprocally mounted in a wall of the casing with one end exposed at the outer surface of the unit and the other end contacting the switch means for actuation thereof as the rod is moved rearwardly.

9. The emergency light unit of claim 1 wherein the unit casing is approximately 4 1/2 inches long, 3 inches wide, and 1 inch deep.

10. The emergency light unit of claim 1 wherein except when the lamp means is energized, the maximum current drain on the emergency power supply means in only approximately 1 milliamp.

11. The emergency light unit of claim 3 wherein when the main power is on, all but approximately 1 milliamp of charging current produced from the main power supply is delivered to charge the emergency power supply batteries, the circuit means offering a relatively high impedance path for the charging current except through the emergency power supply batteries.

12. The emergency light unit of claim 11 wherein the main power is approximately 110 volts, AC, 60 Hertz, and including means for converting the main power to rectified power of a maximum current capacity of approximately 60 milliamps, whereby approximately 59 milliamps are delivered to charge the batteries, and only approximately 1 milliamp is lost in operating the remainder of the electrical circuit means.