Illumination – Door knob or keyhole illuminator
Reexamination Certificate
1999-11-23
2001-10-23
Husar, Stephen (Department: 2875)
Illumination
Door knob or keyhole illuminator
C362S501000, C362S276000, C362S802000, C362S800000
Reexamination Certificate
active
06305814
ABSTRACT:
BACKGROUND—FIELD OF INVENTION
This invention relates to an apparatus and the circuitry used to automatically switch and control the illumination of a keyhole.
BACKGROUND—DESCRIPTION OF PRIOR ART
Previous keyhole illuminating devices were designed for mounting adjacent to a keyhole. Although these devices provide illumination for a keyhole, they have an objectionable feature in that, the illuminating apparatus and the cylinder are mounted apart from each other. Because of this separation, the light emitted from the source is scattered and may improperly illuminate a keyhole. Additionally, these devices do not provide any means for activating the illumination automatically, human intervention is required.
Each prior art cited has its own distinct feature and is successful in illuminating a keyhole. However, they have other drawbacks in the method used to initiate the illumination process. First, a contact switch must be pressed in the dark, an inconvenient task indeed, before illumination can occur. Second, since the illumination is cycled, this switch must be pressed repeatedly if the duration is insufficient.
U.S. Pat. No. 5,634,710 to DiRusso and Tarlow (1996) disclosed a keyhole light made up of three elements, an electroluminescent light display, an electronic module, and a conductive switch panel. Although this apparatus illuminates a keyhole, it has an objectionable feature in that, all parts with the exception of the electronic module, are susceptable to damage because, they are exposed and not concealed within an enclosure. Double sided adhesive tape used to hold parts on a surface is not reliable for long term use.
U.S. Pat. No. 4,310,873 to Bean (1980) shows a structure positioned above a lock cylinder and door knob. Although there is illumination provided for the keyhole, it has a drawback in the way the illumination is projected in illuminating a keyhole. The illumination is pointed downwards on top of the lock cylinder, casting a shadow, which may not properly illuminate the keyhole. The duration of illumination provided by the timing circuit, may be insufficient to allow for key insertion.
Another U.S. Pat. No. 4,281,368 to Humbert (1979), proposes a keyhole illuminating apparatus comprising of an elongated tubular housing adapted for mounting on a surface adjacent a keyhole, uses a light bulb which is actuated by tightening a translucent cap to make contact with the positive terminal of the battery.
The three references cited above have a common drawback in that, the illumination of a keyhole depends on an inconvenient and difficult task of finding a contact switch to be pressed, in dark or subdued lighting conditions.
My invention is unique in that, it eliminates manual switching, an illuminated keyhole is readily available in either dark or subdued lighting conditions for key insertion. The illumination for a keyhole is automatically activated and deactivated at prescribed times.
The disadvantages of my invention which describes a keyhole lighting fixture are:
(a) The brass material from which the keyhole lighting fixture is made, is expensive to purchase and manufacture. However, other materials such as various plastics can be used to reduce cost of manufacturing significantly.
(b) The printed circuit board, light emitting diode, and wiring are all housed within the keyhole lighting fixture's top housing, this results in overcrowding because of the limited space which is available, it does not however limit the scope and purpose for its use.
OBJECTS AND ADVANTAGES
Accordingly, several objects and advantages of the present invention are:
(a) to provide unobstructed access of a keyhole for key insertion;
(b) to provide control and automatically illuminate a keyhole only at prescribed times, thereby conserving energy and extending battery life;
(c) to provide simultaneous control and sufficient illumination by a circuit designed for low voltage operation;
(d) To provide sufficient illumination by using a low current light source such as a Light Emitting Diode (LED);
(e) To provide easy installation of the keyhole lighting fixture on a door surface with only a screw driver;
(f) Human intervention is reduced to just changing a battery only when the need arises.
(g) Has a very pleasing character shape.
Further objects and advantages are, to simplify battery replacement without the need to disassemble the keyhole lighting fixture, and reduce the frequency of battery replacement by using a high energy battery. Redesign the present keyhole lighting fixture to accept rechargeable batteries, that have an advantage over standard batteries in that, the same batteries are used repeatedly by recharging them in a charger. Rechargeable batteries, unlike standard batteries, are more convenient to use, and results in savings to the consumer. To design a circuit which would detect movement in the proximity of a keyhole, and illuminate it only when a dark condition is satisfied. Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.
REFERENCES:
patent: 4281368 (1981-07-01), Humbert
patent: 4293894 (1981-10-01), Blank
patent: 4310873 (1982-01-01), Bean
patent: 4745527 (1988-05-01), Belverio
patent: 5057975 (1991-10-01), Evigan
patent: 5634710 (1997-06-01), DiRusso
patent: 5996383 (1999-12-01), Adelmeyer et al.
The Colombia Encyclopedia.Sixth Edition, Photoelectric cell.*
Mototrola Optoelectronics Device Data Catalog, Fifth Printing 1989.
Husar Stephen
Lambert Gary E.
Timmer Edward
Ton Anabel
LandOfFree
Keyhole lighting fixture does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Keyhole lighting fixture, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Keyhole lighting fixture will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2615184