Title of Invention

IMPROVEMENT IN ELECTRIC LIGHT BULB

Abstract

An improvement in or relating to electric light bulb which consist of two filaments, a selector switch, a sealed glass envelope and a base fixed to the glass envelope in the same manner as a conventional electric light bulb. The two filaments work independently of each other and one at a time When the selector switch is electrically connected to the phase terminal of the bulb then the first filament will be shorted and the second filament will give service and this filament will stay in service until it is damaged or taken out of selection When we want to use the other filament then the selector switch is electrically connected to the neutral terminal of the bulb then the second filament will be shorted and the first filament will give service.

Full Text

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the improvement in electric Light bulb wherein the novel inventions include two filaments and one selector switch; each filament works independently of the other and one at a time; Any of the two filament can be selected with the help of the selector switch and after the chosen filament completes its life, is burnt, fused or damaged, the other filament is selected through the selector switch; in this way life of a single electric bulb is doubled at almost the same cost as that of die single filament bulb. 2. Description of the Related Art hi general lighting electric bulbs available in the market consist of a single filament and when this filament completes its life, is burnt, fused or damaged then the whole bulb is replaced instead of changing the filament thereby increasing the cost. In rural areas people have to travel large distances in order to buy an electric bulb, whereas in urban areas due to voltage fluctuations the electric bulb gets damaged, burnt or fused. SUMMARY OF THE INVENTION To solve the above-described problems, it is an objective of the present invention to make the present invention more advantageous and technically sound than the conventional electric bulb and the defect has been removed by adding two filaments in place of one filament in the electric bulb assembly. The two filament electric light bulb includes a sealed glass envelope and a base fixed to the glass envelope in the same manner as a conventional electric light bulb. The two filament electric light bulb is lightable one filament at a time. A filament is selected with the help of a selector switch. A selector switch is a simple mechanism made up of brass sheet folded into T-shape and revetted to a brass metal base. T- shaped switch is slightly bent into a bow to give it a spring action so that the contact with the phase or neutral terminal of the bulb is firm. The selector switch can be swung through a small angle as the revetting point acts as a pivot. By moving the selector switch left or right, the switch can be electrically connected to phase or neutral terminal of the bulb. An improvement in electric light bulb wherein there is evacuation and gas filling tube, neutral wire, phase wire, insulating material and a base fixed to the glass envelope in the same manner as hi a conventional electric light bulb characterized in mat there are two filaments and a selector switch to select a particular filament at a time; the selector switch is a simple mechanism made up of brass sheet folded into T-shape and riveted to a brass metal base then it is slightly bent into a bow to give it a spring action so mat the contact with the phase or neutral terminal of the bulb is firm, BRIEF DESCRIPTION OF THE DRAWINGS The above objective and advantages of the present invention will become more apparent by describing in detail preferred embodiments thereof with reference to me attached drawings in which: FIG. 1 is a circuit diagram showing the working of the selector switch. FIG. 2 is a diagrammatic view which illustrates the end view of T - shaped selector switch. FIG. 3 is a diagrammatic view which illustrates the T - shaped selector switch fixed on the bulb base and swung through angle 3 to short common point C with phase terminal of the bulb. FIG. 4 is a diagrammatic view which illustrates an electric light bulb with two filaments and a selector switch. DETAILED DESCRIPTION OF THE INVENTION Now, an electric light bulb with two filaments and a selector switch according to a preferred embodiment of the present invention will be described in detail with reference to the attached drawings As illustrated in FIG. 1 a single phase has to be given at points P and N C is a common point of selector switch S When the selector switch S is in position CP, filament F1L1 is shorted and filament F2L2 is in service that is filament F2L2 will give light. The filament F2L2 will stay in service until it gets damaged or is taken out of selection. When the filament F2L2 gets damaged, selector switch S is put in position CN to make filament FiLl in service, When the selector switch S is in position CN, filament F2L2 is shorted and filament F1L1 is in service that is filament F1L1 will give light The filament F1L1 i will stay in service until it gets damaged or is taken out of selection When the filament F1L1 gets damaged, selector switch S is put in position CP to make filament F2L2 in service When both the filament are damaged or used then the bulb is changed As illustrated in FIG. 2 the end view of the selector switch S made up of folded brass sheet is shown As illustrated in FIG. 3 the T shaped selector switch S is shown fixed on the bulb base and swung through an angle 9 to short common point ( with phase terminal of the bulb. As illustrated in FIG. 4 an electric light bulb with two filaments FILI and F2L2, evacuation and gas filling tube 1, neutral wire 2, phase wire 3, insulating material 4 and a selector switch S with common point ( are shown A view of electric light bulb base showing phase, neutral and common point selector switch S is also depicted. The position of the selector switch determines which of the two filament is in service As described above, the electric light bulb with two filaments and a selector switch according to the present invention has the following advantages First, the life cycle of the electric light bulb is doubled due to the presence of two filaments and the price of the bulb is almost the same Secondly, in rural part of the country where somehow power has reached but the poor masses can not afford to buy a light bulb comfortably, bulbs with double the life and with price almost the same as the conventional bulbs, shall be of reasonable relief Thirdly, even in urban areas and industrial areas lightning bulbs are often damaged due to fluctuations in the power supply voltage and a reserve bulb may not be in stock at that time so by using an electric light bulb with two filaments and a selector switch this problem can be solved While this invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims I CLAIM 1. An improvement in electric light bulb wherein there is evacuation and gas filling tube (1), neutral wire (2), phase wire (3), insulating material (4) and a base fixed to the glass envelope in the same manner as in a conventional electric light bulb characterized in that there are two filaments (FlLl, F2L2) and a selector switch (S) to select a particular filament at a time; the selector switch (S) is a simple mechanism made up of brass sheet folded into T-shape and riveted to a brass metal base then it is slightly bent into a bow to give it a spring action so that the contact with the phase or neutral terminal of the bulb is firm. 2. An improvement in electric light bulb as claimed in claim 1 wherein the bulb consists of two filaments (FlLl, F2L2) working one at a time independently. 3. An improvement in electric light bulb as claimed in any one of the above claims wherein the selector switch's riveting point acts as a pivot and the selector switch is moved left or right to swing it through a small angle. 4. An improvement in electric light bulb as claimed in any one of the above claims wherein the switch is electrically connected to phase or neutral terminal of the bulb. 5. An improvement in electric light bulb as claimed in any one of the above claims wherein the selector switch is moved from riveting point and electrically connected to the phase terminal of the bulb to short filament FIL1 6. An improvement in electric light bulb as claimed in any one of the above claims wherein the selector switch is moved from riveting point and electrically connected to the neutral terminal of the bulb to short filament F2L2. 7. An improvement in electric light bulb as claimed in any of the above claims substantially as described in the specification and illustrated in the accompanying drawings

Documents:

90-del-2004-abstract.pdf

90-del-2004-claims.pdf

90-del-2004-correspondence-others.pdf

90-del-2004-correspondence-po.pdf

90-del-2004-description (comlete).pdf

90-del-2004-drawings.pdf

90-del-2004-form-1.pdf

90-del-2004-form-19.pdf

90-del-2004-form-2.pdf

90-del-2004-form-26.pdf

90-del-2004-form-3.pdf

90-del-2004-form-5.pdf

90-del-2004-others-document.pdf