Led Slidebase Switchboard Lamp

Abstract

A light-emitting diode slidebase switchboard lamp having an LED at one end of an elongated sheath and a rigid, non-conducting base at the other. A resistor and a rectifier positioned in the sheath in axial alignment, each connected to the LED and to terminals positioned along the outside of the sheath. The terminals are cemented to the sheath and have end portions embedded in the base.

Description

BACKGROUND OF THE INVENTION

The invention relates to a slidebase switchboard lamp and more particularly to one employing a light-emitting diode for use in lamp jack panels on switchboards.

The prior art slidebase switchboard lamps have been constructed utilizing filament type glass vacuum enclosures with a life of approximately 1,000 hours. The disadvantage of the vacuum type of device is the short life and easy breakage. The extremely short life causes considerable expense and inconvenience in locating burned out indicator lights on switchboard panels since the primary way a burned out lamp is noted is when a subscriber complains to the operator that his phone is not being connected on outgoing calls or if the operator cannot determine whose line is "buzzing."

SUMMARY OF THE INVENTION

It is an object of the instant invention to provide a slidebase lamp utilizing a light-emitting diode in appropriate circuitry and encapsilated in a compact, non-breakable assembly.

Another object is to provide a device with an extremely long life which is compatible with existing switchboard panel units without any modifications thereto.

Still a further object is to provide slidebase lamps wherein the necessary resistances, polarity diodes and light elements are all housed in the area allocated to the lamp alone in prior art devices.

The lamp of the instant invention includes a slidebase portion with a pair of terminals molded therein. The terminals are secured to a sheath in which is housed a resistor and a diode or full wave rectifier. The resistor and diode are each connected to the terminals and to a light-emitting diode (LED) which is encapsilated in an appropriately colored lens material.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of the invention will become more apparent from the following detailed description and accompanying drawing wherein:

FIG. 1 is a side elevational view of the slidebase switchboard lamp of the present invention;

FIG. 2 is an enlarged longitudinal sectional view through the slidebase lamp of FIG. 1;

FIG. 3 is a transverse sectional view taken along line 3--3 of FIG. 2;

FIG. 4 is a circuit diagram of the slidebase switchboard lamp in accordance with FIGS. 1-3;

FIG. 5 is a circuit diagram of a modified circuit for the slidebase switchboard lamp; and

FIG. 6 is a circuit diagram of another modified circuit utilizing a dual chip LED.

DETAILED DESCRIPTION OF THE DRAWING

Referring to FIGS. 1-3, a slidebase switchboard lamp in accordance with the invention includes a rigid conventional plastic slidebase 1 formed by injection molding and having a central recess 2 therein. The structure of a pointed end 2 and symmetrical sides is consistent with the existing receptables, and the unit is adapted to cooperate in existing lamp receptacles and lamp jack panels. At the opposite end of the device is a semiconductor light-emitting diode (LED) 5 surrounded by a colored glass or plastic material forming a lens of a selected color. The LED has a base 7 and a pair of conductors 9 and 11. Such diodes are commercially available, and two types of colored dome LED's are shown in U.S. Pat. Nos. 3,596,136 and 3,609,475.

The base of the LED 7 is bonded to an end of a cylindrical plastic sheath or housing 13. Attached to the sheath 13 are a pair of contact terminals 15 and 17. The terminals have wing-shaped extension members 15' and 17' respectively and are secured by appropriate cement or adhesive material to the outside of the cylindrical sheath. The terminals 15 and 17 also have centrally extending end portions 19 and 21 respectively molded in the base 1. A load resistance 23 has one conductor 25 soldered to LED 9 and another conductor 27 soldered to portion 19. A diode 29 has a conductor 31 soldered to conductor 11 of the LED and a conductor 33 soldered to portion 21.

The resistance 23 is preferably in the order of a 1,200 ohm, 3-watt resistor. Alternatively, it can be two resistors to provide better heat dissipation. Also, it is possible that a resistance in the form of a substrate semiconductor or the like can be used to provide the proper voltage drop and heat distribution. A combination of any of the above can also be used.

It will be appreciated that the diode 29 and resistor 23 are positioned axially relative to one another so that the diode is not adversely affected by the heat from the resistor. Also, with the resistor 23 positioned adjacent terminal 15 and in view of its proximity to terminal 17, a certain amount of heat dissipation will be achieved. It is also possible to achieve the greatest utilization of space by axially positioning the diode and resistor within the sheath 13 in the manner illustrated in FIG. 2.

FIG. 4 illustrates the circuit of the structure seen in FIG. 2.

FIG. 5 illustrates another preferred embodiment using a full wave rectifier 35 in place of the single diode 29. Rectifier 35 will provide a non-polar type of device which can be used in place of the current glass. vacuum lamp. The rectifier with its diode elements, either individually or in integrated circuit form, are positioned in the sheath in place of diode 29.

It has been found that the instant slidebase lamp can have a projected useful life of 25 to 50 years; whereas the prior art glass vacuum variety has a useful life of only about 1,000 hours. The value of this vast time differential will be appreciated when one considers the cost of locating a glass vacuum lamp failure in a switchboard. With the instant type of device, the LED lamp may well outlast the switchboard in which it is used.

In operation, the end portions 19 and 21 of terminals 15 and 17 are molded into the base 1, and the LED conductors 9 and 11 are soldered to the conductors 25 and 31 of resistor 23 and diode 29, respectively. The sheath 13 is then slipped over the resistor and diode and bonded to the base 7 of LED 5. The sheath is inserted between the terminals 15 and 17, and conductors 27 and 33 are soldered to end portions 19 and 21 respectively. The entire device can then be inserted in the female receptacle of a switchboard indicator assembly in place of the currently used vacuum type light.

FIG. 6 illustrates an embodiment utilizing a dual chip LED 5' having pair of diode chips therein arranged parallel and in opposite polarity. Therefore, the device becomes nonpolar and can be used with either DC or AC. As is know in the art, the normal conducting mode for such devices involves a 11/2 volt maximum voltage drop, whereby each chip in its conducting mode protects the other chip in its nonconducting mode. It will be appreciated that the two chips can both be of the same color or they may be of different colors to indicate polarity.

While one embodiment of the invention has been described, it will be understood that it is capable of many further modifications and this application is intended to cover any variations, uses or adaptions of the invention following in general, the principles of the invention and including such departures from the present disclosure as come within knowledge or customary practice in the art to which the invention pertains, and as may be applied to the essential features hereinbefore set forth and fall within the scope of the invention or the limits of the appended claims.

Claims

1. A slidebase lamp comprising;

a. an elongated housing;

b. a light-emitting semiconductor element on one end of said housing,

c. a pair of elongated terminals outside of and substantially coaxial with said housing;

d. a resistor in said housing,

e. a rectifier in said housing,

f. said resistor, said rectifier, said element and said terminals being connected in series, and

g. said resistor and said rectifier being positioned substantially axially

2. A slidebase lamp as defined in claim 1 wherein said rectifier is a

3. A slidebase lamp as defined in claim 1 wherein said rectifier is a

4. A slidebase lamp as defined in claim 1 wherein said element is a

5. A slidebase lamp as defined in claim 1 including a rigid base positioned at one end of said housing and said element being positioned at the other

6. A slidebase lamp as defined in claim 5 wherein said terminals are

7. A slidebase lamp as defined in claim 1 wherein said housing is an

8. A slidebase lamp as defined in claim 1 including a base positioned at one end of said sheath, and said element in the form of a light-emitting

9. A slidebase lamp as defined in claim 1 wherein said resistor is

10. A slidebase lamp as defined in claim 1 wherein said light-emitting element is encapsulated in a colored nonconducting material.