METHOD OF ENCLOSING U-SHAPED CONTACT PINS IN THE PINCH SEAL OF A LAMP

FIELD OF THE INVENTION

The present invention relates to a method of manufacturing a lamp, for example, to a method of manufacturing a halogen incandescent lamp.

BACKGROUND OF THE INVENTION

Lamps including halogen incandescent lamps are widely used nowadays. For example, Fig.l-a and Fig.l-b shows schematically the front view and the side view of a known lamp comprising: a bulb 1; a luminous element 2 fixed inside said bulb 1; a pinched portion 3 adjacent to said bulb 1, having two rabbets 4 placed symmetrically in the sides of said pinched portion 3; two contact pins 5 extending through said pinched portion 3 and having a U-shape portion not enclosed in said pinched portion 3, each contact pin 5 having a first end 6 electrically connected to said luminous element 2 and a second end 7 positioned in said rabbet 4.

Fig.2 shows a flow chart for a known method of manufacturing a lamp as described in Fig.l-a and Fig.l-b.This method comprises the steps of: connecting 100 a luminous element 2 to two first end 6 of two linear contact pins 5 for producing an assembly ; placing 110 said assembly inside a bulb 1; pinching 120 a portion 3'of said bulb so as to produce a pinched portion 3 enclosing a portion of said contact pins 5; forming 130 two rabbets 4 placed symmetrically in the sides of the pinched portion; bending 140 the contact pins into U-shape and placing 140 two second ends 7 of said contact pins 5 into said rabbets 4. In step 100, in addition to the luminous element 2 and contact pins 5, such an assembly may also comprise other components, such as supporting components and connecting components (e.g. support wire, supply lead, sealing foil).

In above example, the second ends of the contact pins are just placed but not fixed in the rabbets, meaning that the lamp is not strong enough when installed in a lamp holder. Also, the contact pins may easily be deformed.

Moreover, since the step of forming the rabbets and the step of bending the pins are necessary, and the step of bending should be performed after the step of pinching, the manufacturing process is complex and expensive.

OBJECT AND SUMMARY OF THE INVENTION

It is an object of the present invention to provide a simple and cheap method of manufacturing a lamp.

To this end, the present invention proposes a method of manufacturing a lamp, said method comprising the steps of:

- connecting a luminous element to two first ends of two U- shape contact pins for producing an assembly, - placing said assembly inside a bulb so as to not enclose a U-shape portion of said contact pins ,

- pinching a portion of said bulb so as to produce a pinched portion enclosing a portion of said contact pins and two second ends of said contact pins .

According to another aspect of the invention, said method may further comprise a step of: heating said portion of said bulb before pinching.

According to another aspects of the invention, said method may further comprise a step of: moving up the contact pins between heating and pinching so as to seal said two second ends into said portion of said bulb.

According to another aspects of the invention, said method may further comprise a step of: Filling the bulb with a gas and a halogen additive.

This invention thus allows to fixed the second ends of contact pins to the bulb during pinching, therefore the structure of the bulb will be stronger than the known lamp described above.

Moreover, no additional steps of forming the rabbets and bending the contact pins are needed, resulting in a cheap and simplified manufacturing process.

These and other aspects of the invention will be apparent from the description of the present invention with reference to the following figures and claims, to allow one to have a thorough understanding of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be explained, by way of example only, with reference to the accompanying figures, where: - Fig.1-a and Fig.1-b show schematically two views of a known halogen incandescent lamp;

Fig.2 show a flow chart for the method of manufacturing a lamp as described in Fig.1-a and Fig.1-b;

Fig.3-a and Fig.3-b show schematically two views of a halogen incandescent lamp manufactured according to the invention;

Fig. 4 shows a flow chart of the method of manufacturing a lamp described in Fig.3-a and Fig. 3-b;

Fig.5-a and Fig.5-b illustrate the method according to the invention of manufacturing a lamp described in Fig.3-a and Fig.3-b, with 2 different views.

In the above drawings, the same reference symbol indicates the same, similar or corresponding characteristics or functions.

DETAILED DESCRIPTION OF THE INVENTION Fig.3-a and Fig.3-b show schematically two views of a halogen incandescent lamp manufactured according to the invention, wherein Fig.1-a is a front view of the lamp and Fig.1-b is the corresponding side view of Fig.1-a.

The lamp comprises: a bulb 1; a luminous element 2 fixed inside said bulb 1; a pinched portion 3 adjacent to said bulb 1; two contact pins 5 extending through said pinched portion 3 and having a U-shape portion not enclosed in said pinched portion 3, each contact pin 5 having a first end 6 electrically connected to said luminous element 2 and a second end 7 sealed into said pinched part 3.

Fig. 4 shows a flow chart of the method of manufacturing a lamp described in Fig.3-a and Fig. 3-b.

The method comprises steps of: connecting 200 a luminous element 2 to two first ends 6 of two U-shape contact pins 5 for producing an assembly,

- placing 210 said assembly inside a bulb 1 so as to not enclose a U-shape portion of said contact pins 5,

- pinching 220 a portion 3* of said bulb 1 so as to produce a pinched portion 3 enclosing a portion of said contact pins and two second ends 7 of said contact pins 5. In Step 200, in addition to the luminous element 2 and contact pins 5, such an assembly may also comprise other components, such as supporting components and connecting components (e.g. support wire, supply lead, sealing foil).

During the manufacturing process, other steps may also be needed, e.g., closing the bulb, filling the bulb with a gas and an halogen additive through a vent-pipe. Those step being known as such, will not be further described.

Fig.5-a and Fig.5-b illustrate the method of manufacturing a lamp described in Fig.3-a and Fig.3-b with 2 different views according to the invention, wherein Fig.5-a is a side view of the lamp and Fig. 5-b is corresponding front view of Fig. 5-a. Each figure shows four states of the lamp, marked individually as STl, ST2, ST3, ST4.

According to the method of the invention described in Fig.4, the assembly including the contact pins can be placed into the bulb and pinched to produce a bulb with strong structure. However, in some cases, if the bulb is thick enough, the second ends of the contact pins could not be placed into the bulb directly; therefore, additional steps are needed as described below with reference to Fig.5-a and Fig. 5-b. The method comprises all the steps according to Fig.4, and additionally comprises the steps of: - heating said portion 3* of said bulb 1 before pinching. moving up the contact pins 5 between heating and pinching so as to seal said two second ends 7 into said portion 3* of said bulb 1.

With reference to Fig.5-a and Fig. 5-b, state STl shows the lamp being heated by heating means HM in view of pinching. While heating, a portion 3* of said bulb 1 becomes more and more soft. State ST2 shows the bulb 1 still being heated; said portion 3*, for example, made from glass, quartz, or other materials, has been softened through after a period of time; at this time, the contact pins 5 are moved up, except the bulb 1 which stays at the same height. Because of the softened surface of said portion

3*, it is possible for the second ends 7 of the contact pins 5 to seal into the body of said portion 3*. State ST3 shows the bulb 1 being pinched. After the steps of heating and moving the contact pins up, said portion 3* of said bulb 1 has been softened and the second ends 7 of the contact pins 5 have been sealed into the said portion 3*; then said portion 3* can be easily pinched by pinching means PM, so that the contact pins 5 and other parts of the lamp are fixed. ST4 shows a bulb 1 after pinching.

The above embodiments are described only illustratively, and not intended to limit the technique approaches of the present invention. Although the present invention is described in detail referring to the preferable embodiments, those skilled in the art will understand that the technique approaches of the present invention can be modified or equally displaced without departing from the spirit and scope of the technique approaches of the present invention, which will also fall into the protective scope of the claims of the present invention.

Use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in the claims. Use of the article "a" or "an" preceding an element or step does not exclude the presence of a plurality of such elements or steps.