US3675070A

US3675070A - Tubular incandescent lamp

Info

Publication number: US3675070A
Application number: US76773A
Authority: US
Inventors: Evgeny Fedorovich Prytkov
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-09-29
Filing date: 1970-09-30
Publication date: 1972-07-04
Anticipated expiration: 1989-07-04
Also published as: GB1288206A; DE2049001A1; FR2110705A5; NL7014342A

Abstract

A tubular incandescent lamp adapted to be mounted for operation in positions other than horizontal comprising a transparent envelope receiving thereinside a single-spiral incandescent body rigidly connected with a pair of electric leads sealingly secured in said envelope, and at least one holder supporting the incandescent body inside said envelope; the lamp being additionally provided with at least one auxiliary support means including a tube welded to the inner surface said envelope, and with the tube receiving therein a portion of an adjacent one of a holder supporting the incandescent body.

Description

United States Patent Prytkov 51 July 4, 1972 [54] TUBULAR INCANDESCENT LAMP [72] Inventor: Evgeny Fedorovich Prytkov, Bolshevistskaya ulitsa, 30, kv. 3, Saransk Mordovskoi, U.S.SR,

[22] Filed: Sept. 30, 1970 [21] Appl.No.: 76,773

827,274 11/1969 Canada ..313/279 946,149 1/1964 Great Britain 1,527,882 6/1968 France Great Britain ..313/279 Primary Examiner-David Schonberg Assistant Examiner-Paul A. Sacher Attorney-Waters, Roditi, Schwartz & Nissen [5 7] ABSTRACT A tubular incandescent lamp adapted to be mounted for operation in positions other than horizontal comprising a transparent envelope receiving thereinside a single-spiral incandescent body rigidly connected with a pair of electric leads sealingly secured in said envelope, and at least one holder supporting the incandescent body inside said envelope; the lamp being additionally provided with at least one auxiliary support means including a tube welded to the inner surface said envelope, and with the tube receiving therein a portion of an adjacent one of a holder supporting the incandescent body.

2 Claims, 1 Drawing Figure TUBULAR INCANDESCENT LAMP The present invention relates to tubular incandescent lamps adapted to be mounted for operation in positions other than horizontal, including a position when the single-spiral incandescent body of the lamp extends vertically, the lamp being also adapted to withstand vibratory and shock loads.

Commonly known are vibration-proof incandescent tubular lamps, each comprising a transparent envelope having therein a single-spiral incandescent body rigidly connected to a pair of leads sealingly secured in the envelope, and a plurality of discshaped holders supporting the incandescent body in the envelope. In order to prevent displacement of these holders under the action of vibratory loads, the internal surface of the envelope is made so as to include a longitudinally extending rib, this rib being produced during the process of the manufacture of the tubular envelope, and with the disc holders being provided with indentations complementary to the cross-sec-' tional shape of the rib.

Also commonly known is another type of tubular incandescent lamp comprising a transparent envelope having therein a single-spiral incandescent body rigidly connected with a pair of electric leads which are sealingly secured in the envelope, and a plurality of disc-shaped holders supporting the incandescent body within the envelope. In order to prevent deformation of the incandescent body under the influence of external mechanical loads, the holders are built into the sidewall of the envelope from two diametrically opposed sides, whereby indented areas are formed in the respective portions of the external surface of the envelope.

It is a disadvantage of both to afore described prior art structures that the lamps essentially cannot be mounted for operation in positions other than substantially horizontal, lest the incandescent body be subjected to deformation resulting in the eventual destruction of the envelope, under the influence of the weight of the incandescent body and of external mechanical loads.

Among other disadvantages of the known structures for tubular incandescent lamps are that the hard-melting or refractory materials from which the holders for the incandescent body are usually made, are poorly fastened to glass. In order to solder or weld the holders into the envelope, the quarz of the envelope must be heated to a very high temperature, and the holders themselves are required to be very thin, whereby more often than not the sidewall of the envelope is pierced during the holder-securing operation, whereby the percentage of acceptable lamps is greatly reduced in the production thereof. Moreover, the wall strength of the envelope of such a lamp is reduced because of the wall having thin areas at the points where the holders are secured, whereby the lamp becomes more vulnerable to breaking during operation. Additionally the diametrically opposed indentations in the external surface of the lamp, resulting from securing the holders thereinside, are liable to adversely affect the uniformity of the light flux produced by the lamp, which reduces the utility of such lamps for illumination purposes in various optical and illumination systems.

It is an object of the present invention to eliminate the above-mentioned disadvantages.

The main object of the present invention is to provide a tubular incandescent lamp with a single-spiral incandescence body, which is capable of withstanding relatively great external mechanical loads and which should be adapted to be mounted for operation in positions other than substantially horizontal, in view of the modified structure and securing of the holders supporting the incandescent body in the envelope of the lamp.

This object is accomplished by providing a tubular incandescent lamp comprising a transparent envelope having therein a single-spiral incandescent body which is rigidly connected with at least a pair of leads sealingly secured in the envelope, and plurality of wire holders for supporting the incandescent body within the envelope, and wherein, in accordance at least one additional support means including a tube welded to the inner wall surface of the envelope, the tube having fastened thereto a portion of an adjacent one of the plurality of holders supporting the incandescent body.

It is expedient for the tube to be introduced into the envelope through the exhaust portion thereof and to weld the tube thereto, whereby enabling the tube to support and retain the holder for supporting the incandescent body.

The herein disclosed structure of the lamp provides for an increased reliability in the performance thereof when it is mounted for operation in a position other than substantially horizontal, including positions when the single-spiral incandescent body extends vertically, and also when subjected to the influence of external mechanical loads, with this increased reliability being due to the additional linking of the incandescent body with the tubular envelope.

The hereinafter disclosed configuration and structure of the holder supporting the incandescent body provides for the comparatively easily performed connection thereof with the additional support means retaining the holder with reference to the envelope.

The structure of the herein disclosed lamp makes it possible to employ the lamp in a variety of optical and illumination systems, since there is practically no distortion of the light flux produced by the lamp, whereby the lamp can be used for a number of important applications, e.g. in the shooting of cinema and TV films.

The present invention may also be embodied in lamps which are to be used in installations and under conditions, where the presence of vibratory and external shock loads prohibits the employment of lamps of the presently known prior art types.

The economy of the incorporation of lamps according to the invention in various installations and apparatuses is determined by the increased dependability in the performance of these lamps; since it has been found that in various applications one lamp of the herein disclosed structure may replace more than 10 lamps of the previously know types.

The present invention will be better understood from the following detailed description of an embodiment thereof, reference being had to the accompanying drawing depicting a longitudinal sectional and partly schematic view of a tubular incandescent lamp constructed in accordance with the inventron.

Referring now in particular to the drawing, the lamp com prises a generally tubular glass envelope or bulb 1 having an inner surface la, and opposite end portions 2 through which the respectively two metal foil leads extend in a sealed relationship.

Extending along the longitudinal axis of the glass envelope 1 is a single-spiral incandescent body 4 supported centrally thereof by a plurality of wire holders 5, each wire holder 5 being shaped as a ring having the external portion thereof extending contiguously with the internal surface of the envelope 1, and with the diameter of the ring being smaller than the intemal diameter la of the envelope 1.

The opposite end portions of the incandescent body 4 are supported in the respective ones of a pair of lead-in wires 6, each wire 6 including a pair of eoaxially wound cylindrical members, with each member being formed by a plurality of coils of tungsten wire, and with the two cylindrical members having different diameters. The smaller diameter cylindrical member of the wire 6 has the same winding pitch as the incandescent body 4, and is threaded or screwed onto the respective end portion of the incandescent body, while the larger diameter cylindrical member of the wire 6 adjoins the internal surface la of the glass envelope 1. The smaller diameter cylindrical member of the wire 6 is formed integral with a longitudinal extension of which the external or free end is welded or soldered to a respective metal foil lead 3.

Welded or soldered to the end portion of the metal foil lead 3, opposite to that to which the extension of the respective smaller diameter cylindrical member of the lead-in wire 6 is with the present invention, the lamp envelope is provided with secured, is an electrode 7 which is connected to a contactmaking socket part 8 of a structure 9 for contacting the respective ceramic end base of the lamp.

The contact-making socket part 8 has a firm electric contact with the electrode 7 and is firmly secured in the ceramic end base structure 9, without requiring the use of any basesecuring composition. When the base of the herein disclosed lamp is assembled, a predetermined quantity of metal is applied into the structure 9, e.g. such as copper-phosphorous alloy or silver solder, whereafter this amount is heated up to its melting point, and the electrode 7 is immersed into the molten metalso as to wet the electrode. When the molten metal is then cooled down so as to solidify, it forms the contact-making socket part 8 onto which the structure 9 of the ceramic end base is secured.

The contact-making socket part 8 is adapted to form an electrical contact with the supply mains (not shown). Disposed adjacent to the portion 10 of one of the holders and snugly receiving this portion therein is a tubular piece 11 which is welded integrally with the exhaust spout of the envelope l. The envelope 1 of the herein disclosed lamp which is provided with this branch piece in the form of the tube 11 which is welded to the envelope body and receives the portion 10 of the holder 5, so as to hold the latter rigidly and reliably secured within the lamp and in a desired position.

The internal diameter of the tube 11 being somewhat greater than the diameter of the wire from which the holder 5 is made, the portion 10 of the latter can be introduced into the tube 11 without requiring any excessive assembling effort.

The portion 10 of the holder 5 is elbow-shaped, so as to prevent direct contact of the tube 11 with the incandescent body 4, lest the latter may be glazed and possibly destroyed in the operation of the lampv When the lamp according to the invention is mounted in a vertical position and connected to the electrical current supply, the tube 11 prevents deformation of the incandescent body 4, and appreciably reduces bending and curving of this body under the influence of its own weight and external mechanical load, since the holder 5 by having its end portion 10 firmly connected with the envelope 1 with the aid of the tube 11 will not change its initial position.

The reduction of the lengths in the supported spans of the single-spiral incandescent body of the lamp intermediate of the points in which this body is firmly supported increases the dependability of the performance of the lamp under the influence of vibratory and shock loads.

We claim:

1. A tubular incandescent lamp comprising:

a transparent envelope having rigidly attached thereto at least a pair of electric leads sealingly secured in said envelope; a singlespiral incandescent body extending axially and centrally within said envelope and rigidly connected with said electric leads; at least one additional support means including a radially inwardly extending tube welded to the inner surface of said envelope; a holder encompassing said incandescent body within said envelope; said holder having a projecting portion fastened within said tube.

2. A tubular incandescent lamp according to claim 1, wherein said tube is introduced into said envelope through an exhaust portion thereof, said tube being welded to the inner surface of said envelope for supporting and retaining said holder within said incandescent body.

Claims

1. A tubular incandescent lamp comprising: a transparent envelope having rigidly attached thereto at least a pair of electric leads sealingly secured in said envelope; a single spiral incandescent body extending axially and centrally within said envelope and rigidly connected with said electric leads; at least one additional support means including a radially inwardly extending tube welded to the inner surface of said envelope; a holder encompassing said incandescent body within said envelope; said holder having a projecting portion fastened within said tube.