GB2162995A

GB2162995A - Light source, mainly an incandescent halogen lamp, with flattened glass envelope, and method for securing its lamp body to a cap or an optical element

Info

Publication number: GB2162995A
Application number: GB08515478A
Authority: GB
Inventors: Istvan Pozsonyi; Gyorgy Szabo
Original assignee: Tungsram Rt
Current assignee: Tungsram Rt
Priority date: 1984-06-25
Filing date: 1985-06-19
Publication date: 1986-02-12
Also published as: IT8521028A0; ATA20985A; HUT37845A; IT1184569B; GB8515478D0; HU190574B; GB2162995B; JPS6145503A; NL8501565A; JPH0325881B2; DE3518427A1; AT391038B

Abstract

The lamp body 1 consists externally of a cylindrical portion 2 and a flattened portion 3 forming an extension of the former 2, with electric terminal wires 4, 5 extending from the flattened portion 3. The lamp body 1 is supported by a cap or some optical element, e.g. a reflecting mirror 8. The fixing between the lamp body 1 and the cap or optical element 8 is assured by a tubular piece 6 pulled over the flattened portion 3 of the glass envelope of the lamp body 1 and secured to the cap or optical element 8. Shoulder(s) (7, 70) are formed at the flattened portion (3) of the glass envelope at its end where the electric terminal wires (4, 5) are led out, or alternatively indentation(s) are formed on the flattened portion (3) of the glass envelope into which split ends of the tubular piece (6) can engage. <IMAGE>

Description

SPECIFICATION Light source, mainly an incandescent halogen lamp, with flattened glass envelope, and method for securing its lamp body to a cap or an optical element The present invention relates to a light source, mainly an incandescent halogen lamp, having a flattened glass envelope, the lamp body of which consists of a cylindrical portion of the envelope at its outer part, a flattened portion forming an extension of the former through which electric teminal wires extend and where the lamp body is supported by a cap or optical element e.g. a deflecting mirror, and where, for securing said cap or optical element to the lamp body, a resilient cylindrical tubular piece pulled over the flattended portion of the glass envelope is employed.Subject of the present invention is, further, a method for securing the lamp body of the light source to the cap or some optical element, e.g. to a reflecting mirror. The solutions according to the invention are preferably applicable to halogen incandescent lamps of focusable design fixed by some mechanical means, where the electric lead wires are directly connected to the lamp socket, as in the case of reflectors and lamps serving for purposes of general or local illumination, such as halogen reading-lamps.

A wide variety of solving similar tasks is known. For example, in the design described in the GP-PS 1 204 624 the mechanical fixing is combined with cementing. The setup of the cap in itself is very complicated, because, beside the rather precarious process of cementing with specified chemical substances (capping putty), mechanical fixing and positioning requires the additional operation of bonding-in the indentations provided on the metal cap. Beside the complexity of this method, its main drawback is that the increased requirements raised by halogen incandescent lamps can not always be met by the heat resistance of capping putties.

In FRG Patent Specification DE 2 527 208 the fixing between the light source and cap and the task of accurate focusing are solved in a very simple way. Here, a cylindrical tubular piece of any suitable generatrix is pulled over the flattened portion of the glass envelope of the lamp body, where the required clamping effect is provided by the force arising with the elastic deformation of said tubular piece.

Thus, the fixing for maintaining the required relative position of parts is provided by friction between the tubular piece and the flattened portion of the glass envelope. Drawback of this method is that the fixing is not too tight, so that the lamp body can be pulled out axially from the cap against the friction force, unless the electric lead wires are secured to the corresponding element of the cap by welding or some other way.

Aim of the present invention is provide for a method by which the cap or optical element can be secured in a reliable and relatively simple way to the lamp body, avoiding the use of cementing processes.

According to the invention, the set aim is achieved by forming a shoulder on the flattened portion of the glass envelope whereby axial dislocation of the lamp body is prevented by making the securing tubular piece about on the shoulder. The same aim can be reached by providing indentations, instead of a shoulder, on the flattened portion of the glass envelope and by making corresponding indentations on the tubular piece as well.

Correspondingly, the subject of the present invention is a light source, mainly a halogen incandescent lamp, having a flattened glass envelope, the lamp body of which is constituted externally by a cylindrical portion of the glass envelope, further, as an extension of the latter, by a flattened portion of said glass envelope and by electric terminal wires led out from said flattened portion, and where the lamp body is secured to the cap or optical element by a resilient cylindrical tubular piece pulled over the flattened glass envelope of the lamp body and fixed to said cap or optical element and where, for preventing the envelope from moving axially relative to the tubular piece and where said tubular piece can abut, a shoulder is provided on the lamp body at the end of the flattened portion of the glass envelope where the electrical terminal wires are led out.The lamp body of the light source, according to the invention, is fixed to the cap or optical element, e.g. to a reflecting mirror, in such a way that two fixing lugs are provided on the tubular piece, e.g. by bending them out from the wall of said tubular piece and-in the course of assembly---com- pressing from the direction of the fixing lugs and by means of the latter, the two sides of the tubular piece previously secured to the cap or optical element, and inserting the flattened portion of the glass envelope of the lamp body into the tubular piece thus compressed, then after passing the shoulder through the tubular piece, the compressive force is removed.

Another embodiment of the invention is a light source, mainly a halogen incandescent lamp, having a flattened glass envelope, the lamp body of which is constituted externally by a cylindrical portion of the glass envelope, further, as an extension of the latter, by a flattened portion of said glass envelope, and by electric terminal wires led out from said flattened portion, and where the lamp body is secured to the cap or optical element by a resilient cylindrical tubular piece pulled over the flattened glass envelope of the lamp body and fixed to said cap or optical element, and where, for preventing the envelope from mov ing axially relative to the tubular piece, inden tation(s) is (are) provided in the lamp body on the flattened portion of the glass envelope to hold the tubular piece in place.

Fixing of the lamp body of the light source according to the invention to the cap or optical element, e.g. reflecting mirror, can, further, be achieved also by providing a fixing lug on the tubular piece, purposefully by means of bending it out from the wall of said tubular piece, and-in the course of assem bly-compressing-from the direction of the fixing lugs and by means of the latter-the two sides of the tubular piece previously secured to the cap or optical element and insert ing the flattened portion of the glass envelope of the lamp body into the tubular piece thus compressed, then, when the flattened portion of the glass envelope is fully surrounded by the tubular piece, the compressive force is removed and, at the indentation(s) on the flattened portion of the glass envelope, the tubular piece is compressed again, producing its permanent deformation. It is recommended to split up the tubular piece at the indentation(s) before making the compressions in order to facilitate pressing.

When a shoulder is to be formed, it is advisable to form the shoulder on one side or, preferably, on both narrower sides of the flattened portion of the glass envelope.

The shoulder has to be made so high as to satisfy the mechanical requirements, but it is advisable to make it reach up to two-thirds of the height of the flattened portion of the glass envelope.

The width of the shoulder (i.e. how high should it emerhe from the surface of the flattened portion of the glass envelope) is always determined by the difference between the dimension of the tubular piece and that of the flattened part of the glass envelope, as well as by the elastic deformability of the tubular piece, but should preferably lie between 0.15 and 0.30 mm.

The invention is described in more detail in the basis of examples, with reference to the accompanying drawings. In the drawings Figure 1 is an assembly drawing showing the sectional front view of a halogen readinglamp, having a lamp body provided with a shoulder, Figure 2 is a side view of the halogen reading lamp of Fig. 1, Figure 3 is an assembly drawing showing the sectional frunt view of a halogen lamp, having indentations on the lamp body and Figure 4 is a side view of the halogen lamp of Fig. 3.

In Figs. 1 and 2 a 1 2-volt 20-watt halogen reading-lamp is shown with a lamp body 1 having an envelope made of vycor or hard glass, built up of a cylindrical portion 2 and a flattened portion 3, and containing electric terminal wires 4 and 5. On the flattened portion 3 of the glass envelope, shoulders 7 and 70 can be seen on which a tubular piece 6 fixed to a reflecting mirror 8 abuts. The tubular piece 6 is secured to the reflecting mirror 8 by riveting fixing lugs 10 and 11 forming an integral piece with the tubular piece 6 to the reflecting mirror 8, then after pressing from the directions of the fixing lugs 10 and 11 the sides of the cylindrical tubular piece 6 to make it oval, the rectangular flattened portion 3 of the glass envelope of the lamp body is inserted into the tubular piece from the inside of the reflecting mirror 8.The tubular piece 6 is deformed by means of a special tool to such an extent to permit the shoulders 7 and 70 to be pressed through the tubular piece without causing excessive mechanical stresses. As soon as the shoulders 7 and 70 have got through the tubular piece 6, the compressive force is removed, whereafter the tubular piece 6 again assumes its cylindrical shape, abutting on the shoulders 7 and 70, firmly surrounding the flattened portion 3 of the glass envelope, ensuring its required axial position. Displacement of the lamp body 1 in the opposite direction is prevented by the abutment of the cylindrical portion 2 of the glass envelope on the reflecting mirror 8. The figures show the state preceding the insertion of the halogen reading-lamp into a socket 9.It is easy to perceive that without the presence of shoulders, by trying to insert the lamp into the socket 8 incorrectly, while electric terminal wires 4, 5 fail to get into the corresponding holes of the socket 9, lamp body 1 would be pulled out of the tubular piece 6 or the reflecting mirror 8 under the effect of the applied pushing force.

In Figs. 3 and 4 an arrangement essentially similar to that described above is shown with the difference that here, instead of the shoulders 7 and 70 simulataneously with fiattening, alsio indentations 1 2 and 1 3 have been made on the flattened portion 3 of the lamp body 1 and, during assembly, the tubular piece 6 previously split up is compressed at the indentations 1 2 and 13, ensuring thereby proper positioning of the lamp body 1.

Hence, by the arrangement, in the case of light sources corresponding to the invention, firm fixing between the cap or optical element and the lamp body is ensured by means of pure mechanical means and fully eliminating any cementing techniques in a much simpler way than with the methods known so far and, at the same time, more reliably.

Claims

1. A light source, e.g. a halogen incandescent lamp with a flattened glass envelope comprising a lamp body consisting of a cylindrical portion of the glass envelope at its outer part and a flattened portion which forms an extension of the former and through which electric terminal wires extend, the lamp body being supported by a cap or optical element, e.g. a reflecting mirror, a resilient cylindrical tubular piece pulled over the flattened portion of the glass envelope for securing said cap or optical element to the lamp body, and wherein the flattened portion is provided with its end remote from the cylindrical portion of the glass envelope.

2. A light source as claimed in claim 1, wherein the shoulder(s) are formed at the narrower side(s) of the flattened portion of the glass envelope.

3. A light source according to claim 1 or 2, wherein the shoulder(s) extend at most up to 2/3 of the height of the flattened portion of the glass envelope.

4. A light source according to any preceding claim, wherein the shoulder(s) project by 0.15 to 0.30 mm from the surface of the flattened portion of the glass envelope.

5. A method of fixing the lamp body of a light source according to claim 1 to the cap or optical element, e.g. reflecting mirror, comprising forming on the tubular piece two fixing lugs, preferably by bending them out of the wall of the tubular piece, and-in the course of assembly-compressing from the direction of the flixing lugs and by means of the latter, the two sides of the tubular piece previously secured to the cap or optical element, and inserting the flattened portion of the lamp body into said tubular piece thus compressed, then after passing the shoulder(s) through the tubular piece, removing the compressive force.

6. A light source, e.g. a halogen incandescent lamp, having a flattened glass enveloope, the lamp body of which is constituted externally by a cylindrical portion of the glass envelope, and, as an extension of the latter, by a flattened portion of said glass envelope and by electric terminal wires led out from said flattened portion, and wherein the lamp body is supported by a cap or an optical element, e.g. reflecting mirror, and wherein furthermore the fixing between the lamp body and the cap or optical element is assured by a resilient tubular piece pulled over the flattened portion of the glass envelope of the lamp body and secured to the cap or optical element, the flattened portion of the glass envelope being provided with indentation(s) for receiving the tubular piece.

7. A method of securing the lamp body of the light source according to claim 6 to a cap or an optical element, e.g. reflecting mirror, comprising providing the tubular piece with two fixing lugs made e.g. by bending them out of the wall of the tubular piece and, in the course of assembly, compressing from the direction of the fixing lugs and by means of the latter, the two sides of the tubular piece previously secured by means of the fixing lugs to the cap or optical element inserting the flattened portion of the glass envelope of the lamp body and, as soon as the tubular piece fully surrounds the flattened portion of the glass envelope, removing the compressive force, and at indentation(s) on the flattened portion of the glass envelope, compressing the tubular piece is compressed by means of a special tool, causing permanent deformation.

8. A method according to claim 7, wherein the tubular piece is split at the indentation(s) previous to the assembly operation or before applying the compressive force.

9. A light source according to claim 1 substantially as herein described with reference to and as shown in Figs. 1 and 2 of the accompanying drawing.

10. A method of fixing according to claim 5 substantially as herein described with reference to and as shown in Figs. 1 and 2 of the accompanying drawing.

11. A light source according to claim 6 substantially as herein described with reference to and as shown in Figs. 3 and 4 of the accompanying drawing.

1 2. A method according to claim 7, substantially as herein described with reference to and as shown in Figs. 3 and 4 of the accompanying drawing.