Title of Invention

"AN IMPROVED INCANDESCENT LAMP ASSEMBLY"

Abstract

An improved incandescent lamp assembly which comprises in combination, a single ended capsule having a press seal thereof, one or more filaments located inside the capsule, current connection leads extending from the press seal; a cylindrical cup portion with a slit on the top portion thereof for receiving the press seal portion of said capsule; characterized by: a socket means closed at one end with an insulted material in which the said electrical connection leads are embedded, the open upper portion of the socket means receiving said cup in a snug yet adjustable manner; one or more vertical weld means for weldably connecting said socket means to said cup, and one or more horizontal weld means located between said vertical weld means, pair of connection prongs extending outwardly and downwardly from said insulating material; and a hallow stepped ring with a stepped annular ring means and a flat collar means, the stepped ring means receiving in its hollow portion, the socket means in a sealed relationship, with said horizontal weld means being weldably sealed on the top surface said stepped annular ring.

Full Text

Field of the invention The present invention relates to improved incandescent lamp assembly. More particularly, the present invention relates to novel incandescent lamp and socket assembly, which is simple to assemble and easy to align with respect to the reflector with which it will be generally used. The present invention also relates to a method of assembling the incandescent lamp to the socket and a stepped ring at a predetermined focus with respect to a reference plane, formed by a plurality of projections on the stepped ring. The lamp-socket assembly of the present invention is particularly suitable for use in automotive headlights where the position of the filament of the lamp with respect to the focus of the reflector is of utmost importance for the required light distribution emanating from the headlight beam. Apart from the fact that the lamp must be accurately aligned with respect to the focus of the reflector, it is very important that such alignment is retained in spite of the shock and vibration of the vehicle which may be transferred to the lamp. The present invention ideally satisfied these requirements in an improved and hitherto unknown manner. Background of the invention Lamps, particularly, halogen incandescent lamps are well known in the art. Most known lamps employ glass capsules with at least a filament having lead wires for electrical connections to the filament. The glass capsule may have one end flattened or pinched into a press seal. The glass capsule may be made of high temperature resistant glass such as quartz glass. While, the lamps with a single filament are known two filament lamps for projection of "high beam" and "low beam" are particularly common. For example, US Patent No. 4, 412, 273 granted to Helbig et al. Describes a two filament halogen incandescent lamp. The lamp of this patent is characterised by a socket comprising a cylindrical positioning sleeve, which is fitted into and a cylindrical socket sleeve. After ensuring that the lamp is correctly positioned, so that the filaments will emit light in a predetermined pattern with respect to the base, the two sleeves are welded together. The diameter of the adjustment sleeve and socket sleeve are so well matched that the former is securely seated in the latter, yet adjustable therewith and a plastic element located therein prior to the welding. The adjustment sleeve has a central opening to receive the single ended press seal of the lamp capsule with necessary electrical offset with respect to the axis of the socket. The plastic portion includes a groove in which a sealing ring made of silicone rubber is placed. The entire assembly is fitted with a reflector with the sealing ring ensuring a moisture tight seal. The lamp of the above-disclosed US Patent, however, suffered from certain inherent disadvantages. The base core structure of this lamp assembly was found to be particularly complex and also presented certain manufacturing difficulties. British Patent No. 2 093 632 in attempt to simplify the above construction describes lamp assembly characterised by a two part base in which the base core is made of ceramic. The ceramic core is coupled to the base sleeve by riveting. In order to ensure that some play is left, the structure requires additional riveting and riveting part. The focus of the emanating beam and its optical quality is largely dependent on the manner in which the lamp is secured to its base. The assembly of this patent demands that as little play as possible is used in order to ensure that the lamp does not jump out of alignment with respect to the focal point of the reflector. The main disadvantage of the lamp of this patent has been that the base core is made of ceramic and therefore, that much difficult to manufacture to close tolerances. Therefore, a rivet connection, which is tight and meets tolerance requirements, is difficult to make. US Patent No. 5, 010, 272 of Eckhardt et al discloses a slightly more compact structure where the base is again a two part structure comprising of a base core and a base sleeve. This patent attempts to provide a lamp - base combination which is simple to manufacture and assemble, provides for a connection without any play, and which is self adjusting to compensate for the tolerances of the base core. The assembly is of cementless type. The lamp capsule consists of a single ended bulb having a pinched press seal at one end from which extend the current connection leads. The two-part base consists of a metallic base sleeve and a base core of an insulating material. The base sleeve is a hollow structure and the base core is a cylindrical solid structure having apertures for electrical connections and shaped to snugly fit into the sleeve. Rims and projecting tabs are provided to lock the base sleeve and base core together without play. Objects of the invention The lamp assembly disclosed in US Patent No. 5, 010, 272 is still complicated and the presence of the adjustment sleeve causes manufacturing difficulties and makes the lamp uneconomical. Besides, the very nature of the assembly renders it difficult to ensure that the position of the filament with respect to the focus of the reflector is accurate for optimum performance. Thus, there is a longfelt need for an improved lamp assembly, which is easy and economical to manufacture and simple to assemble and yet without any disadvantages of the prior art. It is therefore an object of the present invention to provide an improved lamp and socket assembly which is economical to manufacture and simple to assemble. It is another object of the present invention to provide a lamp assembly in which it is easily and economically possible to position the filament accurately with respect to the focus of the reflector of the headlight. It is yet another object of the present invention to provide a lamp assembly the focus of , which is resistant to the shocks and other vibrations which the lamp may be subjected to during its normal usage. These and other objects of the present invention are achieved by a novel lamp and socket assembly in which the lamp portion is the conventional capsule type bulb enclosing atleast a filament having lead wires for electrical connections and a pinched flattened plate like portion on the other end having projections on both surfaces. A metallic cup is provided to receive the pinched portion of the glass capsule and consists of flaps to lock on the projections of the flat surfaces of the capsule. The base portion is in two parts comprising of a novel socket and a stepped ring. The special construction of the socket and the stepped ring achieves the objects of the invention in a simple yet novel manner, rendering the lamp of the present invention highly economical and commercially viable. Accordingly, the present invention provides an improved incandescent lamp assembly which comprises in combination, a single ended capsule having a press seal thereof, one or more filaments located inside the capsule, current connection leads extending from the press seal; a cylindrical cup portion with a slit on the top portion thereof for receiving the press seal portion of said capsule; characterized by : a socket means closed at one end with an insulated material in which the said electrical connection leads are embedded, the open upper potion of the socket means receiving said cup in a snug yet adjustable manner; one or more vertical weld means for weldably connecting said socket means to said cup, and one or more horizontal weld means located between said vertical weld means, pair of connection prongs extending outwardly and downwardly from said insulating material; and a hollow stepped ring with a stepped annular ring means and a flat collar means, the stepped ring means receiving in its hollow portion, the socket means in a sealed relationship, with said horizontal weld means being weldably sealed on the top surface said stepped annular ring. Detailed Description of the invention The present invention will now be described with reference to the accompanying drawings in which like parts are identified by the same reference numerals, wherein: Fig. 1 is an exploded view of a conventional lamp and socket assembly; Fig. 2 is an exploded view of the lamp-socket assembly of the present invention; Fig. 3 is a schematic view of the lamp-socket assembly of the lamp of the present invention in which the base portion comprising of the socket and the stepped ring are shown in cross section. Fig. 4 is an exploded view of an alternative embodiment of the lamp assembly of the present invention; and, Fig. 5 is a schematic view of the lamp assembly of Fig. 4 in which the base portion comprising of the socket and the stepped ring are shown in cross section. Referring to Fig. 1, a conventional lamp currently used comprises of a glass capsule 1 enclosing a filament 2. The glass capsule is filled an inert gas, usually alongwith a halogen additive. One end of the glass capsule has a pinched press seal portion 3 with an outwardly extending lug like projection 4 for enabling the capsule 1 to snap fit into a cup portion. The cup portion 5 is metallic and consists of a slit 6' on the top thereof. The slit 6' is so dimensioned that the press seal 4 of the capsule fits snugly in the slit 6'. Extending into the slit 6' are crimps or flaps 6 which snap fit with and locks on to the projections 4 of the capsule. The adjustment sleeve 7 is a cylindrical hat like structure, open on the top to receive the metallic cup 5. The inner diameter of the open portion 9 of the adjustment sleeve 7 is so matched with the outer diameter of the metallic cup 5 that the latter tightly fits into the former. The combined socket and the stepped ring 10 has an insulated portion into which the leads from the filament of the lamp are embedded. The socket and stepped ring 10 has a circular seating flange 11 on which the flange 8 of the adjustment sleeve 7 is welded in the assembled state of the lamp assembly. A pair of pins 12 extend from the insulated portion of the structure 10 to electrically connect the assembly. Figs. 2 and 3 illustrate the lamp-socket assembly of the present invention. The present invention also conveniently employs a glass capsule 1, preferably quartz glass or hard glass, which are resistant to high temperatures, enclosing at least one filament 2. While the particular embodiment of the present invention illustrated in the drawings disclose a single filament, it is within the scope of the present invention to include two filaments or multi filaments for 'high' beam and 'low' beam projections and the reference to filament may be construed accordingly. The glass capsule 1 is filled with inert gas, which has a halogen additive. The base portion of the capsule has a pinched press seal portion 3 having two flat surfaces. Each of the flat plate like surfaces has at least one outwardly extending projection 4 for snap fitting into a metallic cup 5. A pair of connecting leads 15 connected to the filament project from the press seal portion of the capsule. The metallic cup 5 has a slit 6' on its top portion to receive the pinched press seal 3 of the capsule 1 in a snap fit manner. From the walls of the slit 6' extend downwardly projecting flaps 6 which lock on to the projections 4 of the capsule to hold the capsule in a secure manner. The above mentioned features of the present invention are similar to the conventional lamp assemblies. The lamp assembly of the present invention is characterised by novel socket and stepped ring which offer unexpected advantages over the prior art. The novel socket of the present invention is cylindrical in shape and is closed on one end with a plastic or other insulating material in which the electrical terminals are embedded. A pair of connecting prongs or pins 12 project from the insulating material to electrically connect the filament 2 of the capsule 1. The presence of the insulating material ensures that the heat generated by the bulb or the capsule is not transmitted thereto and thus any weakening or deformation thereof is avoided. In addition, the connecting pins 12, which project from the insulated material are automatically insulated from each other and from the headlight assembly. The upper open end of the socket has vertical weld means for welding the socket assembly 7 to the cup 5. As shown in Figs. 2 and 3 the vertical weld means comprise four upwardly projecting lugs 14, which are concentric to the axis of the socket. An alternative embodiment of the vertical weld means is shown in Figs. 4 and 5. In this embodiment, the vertical weld means are in the form of two curved vertical walls 14' integral with and extending from the side wall of the socket 7. These vertical walls may be directly welded to the cup 5. Alternatively, the vertical walls may include therein a plurality of lugs 14, which are welded to the cup 5. Between the vertical weld means 14, 14' are located horizontal weld means in the form of welding flaps or flanges 13. The embodiment shown in Figs. 2 and 3 has four such horizontal weld means whereas the embodiment of Figs. 4 and 5 has two such horizontal weld means. The flaps 13 are flat in nature and form a plane perpendicular to the axis of the socket. The terminal side surface of the flaps 13 form a plane which is termed as a secondary reference plane. The socket 7 is mounted on the stepped ring 11, which has a stepped flat annular ring 16 and a flat collar 17 having three projections. While assembling the lamp, the crest of the projections forming a plane perpendicular to the axis of the ring is regarded the primary reference plane and the axis of the ring is the reference axis. The diameter of the imaginary circle on which the flaps 13 lie and the diameter of the annular stepped ring 16 are so matched that in the assembled state, the flaps 13 are securely seated on the top of the stepped ring 16 and adjustable with respect to each other prior to welding. During assembling, the glass capsule 1 is fixed in the metallic cup 5 by pushing the bulb mechanically into the slit 6' of the cup. The bulb snap fits into the slit 6' with the holding flaps 6 locking against the projections 4 of the flattened end portion of the bulb. Thereafter, the glass capsule with the metallic cup is placed in the socket 7. The outer diameter of the cup 5 and the inner diameter of the socket 7 are so matched that the cup fits snugly into the socket. Yet, the glass capsule with the cup can be tilted in any plane passing through the axis of the socket 7 so that the filament is made exactly parallel to the axis of the socket and at a required distance away from the secondary reference plane to achieve optimum focus. The metallic cup is then welded to the lugs 14 of the socket to securely hold it alongwith the glass capsule in the position of optimum focus. The welding may be spot welding or laser welding. Laser welding is particularly preferred since the use of laser ensures that after welding, the position of the capsule is not altered at all since no forces are applied during laser welding. The sub assembly obtained above is then placed in the stepped ring 11 with the flaps 13 seated on the flat surface of the stepped annular ring 16. The sub assembly can then be moved on the stepped ring so that the filament is accurately placed with respect to the primary reference plane and reference axis. Thus, the present invention makes it possible to position the filament with respect to the reference plane and reference axis by the adjustable movement of the cup/socket assemblies along and about the reference axes and reference plane before finally being welded with the filament at the position of optimum focus satisfying international standards. It must be borne in mind the present invention has been illustrated above with reference to the most preferred embodiment and other modifications and embodiments of the invention are possible without departing from the spirit and scope of the invention. We Claim : 1. An improved incandescent lamp assembly which comprises in combination, a single ended capsule having a press seal thereof, one or more filaments located inside the capsule, current connection leads extending from the press seal; a cylindrical cup portion with a slit on the top portion thereof for receiving the press seal portion of said capsule; characterized by : a socket means closed at one end with an insulated material in which the said electrical connection leads are embedded, the open upper portion of the socket means receiving said cup in a snug yet adjustable manner; one or more vertical weld means for weldably connecting said socket means to said cup, and one or more horizontal weld means located between said vertical weld means, pair of connection prongs extending outwardly and downwardly from said insulating material; and a hollow stepped ring with a stepped annular ring means and a flat collar means, the stepped ring means receiving in its hollow portion, the socket means in a sealed relationship, with said horizontal weld means being weldably sealed on the top surface said stepped annular ring. 2. A lamp assembly as claimed in claim 1 wherein said press seal means has two flat surfaces with at least a locking projection extending outwardly from each flat surface and said cup has locking flap means extending downwardly into the slit thereof so that when the capsule is pushed into the cup, the locking projections lock with said locking flaps so that the capsule is held by the cup means without any play. 3. A lamp assembly as claimed in claim 1 or 2 wherein said vertical weld means consist of a plurality of upwardly projecting lugs, said lugs being welded to said cup after the cup is positioned inside said socket means at a position of optimum focus. 4. A lamp assembly as claimed in claim 1 or 2 wherein said vertical weld means consist of at least a pair of vertical walls integral with and extending from the side wall of the socket, said vertical walls being weld connected to the cup means. 5. A lamp assembly as claimed in claim 4 wherein plurality of said lugs are located on said vertical walls, said vertical walls being weld connected to said cup through said lugs. 6. A lamp assembly as claimed in any preceding claim said horizontal weld means consist of a plurality of weld flaps located between said vertical weld means, the diameter of the imaginary circle on which said weld flaps lie matching with the diameter of the flat surface of the stepped annular ring so that when the socket means is inserted in to the hollow portion of said stepped ring means, said weld means are seated on the flat surface of the said stepped annular ring. 7. A lamp assembly as claimed in claim 6 wherein said plurality of horizontal weld flaps consist of either four weld flaps or two weld flaps. 8. An improved incandescent lamp assembly substantially as herein before described in and with reference to Figures 2 to 5 of the accompanying drawings.

Documents:

608-del-1999-abstract.pdf

608-del-1999-claims.pdf

608-del-1999-correspondence-others.pdf

608-del-1999-correspondence-po.pdf

608-del-1999-description (complete).pdf

608-del-1999-drawings.pdf

608-DEL-1999-Form-1.pdf

608-del-1999-form-19.pdf

608-del-1999-form-2.pdf

608-del-1999-form-3.pdf

608-del-1999-form-4.pdf

608-del-1999-gpa.pdf

608-del-1999-petition-138.pdf