EP0061757A2 - Method for manufacturing a pinched seal for an electric lamp envelope and pinching device for carrying out the method - Google Patents

Abstract

The vessel melting of a lamp vessel end designed as a pinch (2) has 0.2 to 0.4 times the length (L) of the lamp vessel diameter (D), the end face (7) closing the lamp vessel (1) being essentially flat . In order to achieve gas-tight vessel melting suitable for highly mechanized production, the pinch (2) is provided with depressions which are arranged directly in the border area of the pinch glass to the thickened middle part (5) surrounding the pump tube (4). The depressions preferably have the shape of conical blind holes (9) which tangent to the pump tube (4). Other depressions are designed as grooves that run parallel and / or at right angles to the longitudinal axis of the lamp in the crushing surface. The lamp is further processed in a conventional manner, with different types of base being possible. The pinch is equally suitable for incandescent and discharge lamps, in particular for low-pressure mercury discharge lamps.

Description

The invention relates to an electric lamp with a vessel melting formed as a pinch, in which a frame structure, which consists of two power leads, between which a coil is tensioned, and optionally consists of a holder and a pump tube, fused to one end of a tubular lamp vessel made of glass is.

Vascular seals of the type described here are known. Their application extends to lamp vessels in a certain diameter range, whereby the upper limit is set by manufacturing technology. With increasing lamp vessel diameter, the increasing glass masses are difficult to control, the length and / or the width of the pinch taking on undesirable dimensions. In the case of larger diameters to be processed, the squeezing technique is therefore departed from and the well-known foot melting process is used. A plate tube is usually processed with two multi-part power supplies, between which a filament is stretched, and possibly a holder and a pump tube to form a lamp base, which is then fused to the lamp vessel end to be sealed.

Another type of vessel melting can be carried out with the help of a press glass base, which essentially also contains the aforementioned components. Both methods have in common that a foot part must be made before the actual melting process, where due to additional preliminary products and machines.

The object of the invention is to avoid the material and cost-intensive production of the type described above and to make the cheaper crimping technology usable also for lamp vessel melts with a larger diameter. The known methods should remain applicable for the base of the lamp.

The electric lamp with the features mentioned in the preamble of the main claim is characterized in that the end face terminating the lamp vessel essentially forms a plane and is arranged at right angles to the outer surface of the lamp vessel, the transition of these two surfaces to one another essentially in the form of a circumferential edge is formed, and that the length of the pinch arranged diametrically to the lamp vessel and starting from the end face in the lamp axis longitudinal axis is 0.2 to 0.4 times the outer diameter of the lamp vessel and the pinch width is equal to or less than the outer diameter of the lamp vessel. The squeeze cross-section has essentially a rectangular shape with a thickened central part. The power supplies are advantageously in one piece and matched to the glass with their coefficient of thermal expansion.

In order to achieve a gas-tight vessel melting in the critical area of the relatively thick pump tube and, if applicable, the power supply lines, in particular in the production on mechanized production machines, the side faces of the pinch which are arranged diametrically to the lamp vessel are the pinch width at least in the border area of the crushed glass to the thickened middle part surrounding the pump tube with depressions. The recesses can take various forms and arrangements:

In a preferred embodiment the depression consists of a round or e.g. square blind hole, which is arranged directly in the border area of the pinch glass to the thickened middle part of the pinch. It is sufficient if there is only one such blind hole on each side surface. Likewise, however, several blind holes can be arranged on each side surface, the distribution of which preferably lies again in the border region of the crushed glass to the thickened central part of the crushed area. The blind holes are approximately frustoconical or pyramid-shaped, the depth of which is slightly more than half the pinch thickness. In the case of square blind holes, all edges are rounded to avoid tension in the crushed glass.

Instead of or in addition to the blind holes, the side surfaces of the pinch can be provided with one or more grooves in other proven embodiments. The grooves are essentially rectangular in cross section, but taper somewhat as the depth of the groove increases. The groove depth is less than a quarter of the pinch thickness. All groove edges are rounded to avoid tension in the crushed glass. Different designs are conceivable with regard to the arrangement of the grooves. In one exemplary embodiment, a groove is arranged on each side surface of the pinch, which is approximately in the middle and at right angles to the longitudinal axis of the lamp over the entire pinch width, that is to say also over the thickened one Middle part extends. Furthermore, a groove guide parallel to the lamp longitudinal axis is conceivable, which is then advantageously arranged in the border area of the crushed glass to the thickened central part of the crushing. As a further exemplary embodiment shows, combined grooves are also possible, which are composed of individual grooves arranged perpendicularly and parallel to the lamp axis and, for example, result in the shape of a T.

In a preferred embodiment, this type of squeezing can be used with low-pressure mercury discharge lamps, each of the two lamp ends having such a squeezing. Each lamp end is provided with a holder to which a cap shielding the filament is attached. At least one of the two lamp vessel ends is provided with a pump tube through which the lamp is pumped and filled and which is then melted close to the pinch.

The device for producing an electric lamp according to the invention essentially has a pair of crimping jaws. Each of the squeeze jaws is provided with at least one shaped element which is raised in this and in accordance with the desired number and shape of the lamp vessel end. During the squeezing process, the shaped elements force the softened glass to be squeezed closer to the pump tube and possibly interrupt capillaries remaining on both sides of the pump tube and, if applicable, the power supply lines. The interior of the lamp vessel is exposed to a certain excess pressure immediately after the squeezing process - even while the end of the lamp vessel is softened and the squeeze jaws are closed - causing the squeeze to take on its final shape holds. This form blowing produces, in particular, the relatively angular transitions of the lateral surface of the lamp vessel to the essentially flat end surface arranged at right angles thereto.

The described squeeze is not limited to mercury vapor low-pressure discharge lamps. In the same way, incandescent lamps can also be produced with a glass vessel without the technology having to be changed significantly. Here, too, two power supply lines, between which a filament is stretched, as well as a holder and a pump stem for a lamp frame are required. In this case, the holder serves as a spiral holder.

The electric lamp with the vessel melting according to the invention enables cheaper production of mass types of both incandescent lamps and discharge lamps, since no actual foot production is required. The end of the lamp vessel to be melted down no longer has to be preformed, such as rolled-up bulb ends for fluorescent lamps. The plate required for foot production is completely eliminated and the length of the pump tube can be shortened. Instead of the three-part power supplies otherwise used, one-piece power supplies can now be used. The lamps can also be easily produced in large quantities on mechanized production machines, since the elements which are arranged in the crimping tools and produce the depressions in the crimp create a seal between the crimping glass and the pump tube with high reliability. The arrangement of the depressions can be adapted to the future use, in particular in the case of the groove design. Due to the relative achieved with the help of the new crushing technique Edged transitions between the outer surface and the extremely short pinch in relation to the outer diameter of the lamp vessel can be placed on the pinched lamp vessel base of the usual type, which may be sealed by means of the pump tube, especially the short second pin base, particularly in the case of fluorescent lamps.

• Figur 1 zeigt stark schematisiert eine Quetschung an einem Lampengefäßende;
• Figur 2 zeigt die Veränderung des Lampengefäßendes durch das Formblasen;
• Figur 3 zeigt einen Schnitt eines gequetschten Lampengefäßendes mit runden Sacklöchern;
• Figur 4 zeigt die Seitenansicht der Figur 3 im Teilschnitt;
• Figur 5 zeigt die Draufsicht der Figur 4;
• Figur 6 zeigt ein anderes Beispiel mit mehreckigen Sacklöchern;
• Figur 7 zeigt ein gequetschtes Lampengefäßende mit Quer-Nut;
• Figur 8 zeigt ein weiteres Beispiel eines gequetschten Lampengefäßendes mit einer T-Nut.
• Figur 9 zeigt ein gequetschtes Lampengefäßende am Beispiel einer Leuchtstofflampe;
• Figur 10 zeigt die Seitenansicht der Figur 9;
• Figur 11 zeigt schematisiert eine Leuchtstofflampenquetschung mit einem aufgekitteten Sockel;
• Figur 12 zeigt schematisiert ein anderes Beispiel einer Leuchtstofflampenquetschung mit einem Sockel;
• Figur 13 zeigt schematisiert ein alternatives Ausführungsbeispiel einer Leuchtstofflampenquetschung mit einem Sockel;
• Figur 14 zeigt schematisiert eine mit Glassockel versehene Leuchtstofflampe.

The invention is explained in more detail with reference to the following figures:

• FIG. 1 shows, in a highly schematic manner, a crush on a lamp vessel end;
• FIG. 2 shows the change in the end of the lamp vessel due to the blow molding;
• Figure 3 shows a section of a pinched lamp vessel end with round blind holes;
• Figure 4 shows the side view of Figure 3 in partial section;
• Figure 5 shows the top view of Figure 4;
• Figure 6 shows another example with polygonal blind holes;
• FIG. 7 shows a pinched lamp vessel end with a transverse groove;
• FIG. 8 shows a further example of a pinched lamp vessel end with a T-groove.
• Figure 9 shows a pinched lamp vessel end at the case play a fluorescent lamp;
• Figure 10 shows the side view of Figure 9;
• Figure 11 shows schematically a fluorescent lamp pinch with a cemented base;
• FIG. 12 schematically shows another example of a fluorescent lamp pinch with a base;
• Figure 13 schematically shows an alternative embodiment of a fluorescent lamp pinch with a base;
• FIG. 14 schematically shows a fluorescent lamp provided with a glass base.

The lamp vessel 1, shown in a highly schematic form in FIG. 1, has a pinch 2 in which two power supply lines 3 and a pump tube 4 are enclosed. The pump tube 4 is guided through the middle part 5 of the pinch 2, which is why the pinch 2 is somewhat thickened at this point (see also FIG. 2).

In FIG. 2 and in all the other figures, the same parts are provided with the same numbers. The dashed line 6 indicates the shape of the lamp vessel immediately after the squeezing process. A certain excess pressure P is exerted on the interior of the lamp vessel 1 by blowing in air, for example, the squeeze jaws still being in the closed position and the glass still softened by the squeezing process. Due to this overpressure P, the end of the lamp vessel 1 is inflated by the amount V and receives the final shape specified by the pinch jaws. The one that closes the lamp vessel 1 End face 7 then essentially forms a plane which is arranged at a right angle to the outer surface of the lamp vessel 1. The transition of these two surfaces to one another is essentially in the form of a peripheral edge. The length L of the pinch 2 extending from the end face 7 is 0.2 to 0.4 times the outer diameter D of the lamp vessel 1 and the width B of the pinch 2 is smaller than the outer diameter D of the lamp vessel 1.

The end of the lamp vessel 1 which is separated and shown schematically in FIGS. 3 to 5 has a pinch 2, in which two power supply lines 3 and a pump tube 4 are enclosed. A coil 8 is stretched between the current leads 3. The vessel melting may belong to an incandescent or discharge lamp, the filament 8 being an incandescent filament of an incandescent lamp or an electrode filament of a low-pressure mercury discharge lamp. The pinch 2 encloses the pump tube 4, which has a relatively large diameter, and is made thickened in the central part 5. In the border area of the pinch 2 to the thickened central part 5, a depression is made on each of the side surfaces. The depression is designed as a frustoconical blind hole 9 and touches the pump tube 4. The lateral narrow surfaces of the pinch 2, which form the pinch thickness, are each provided with a notch 10. A lamp base (not shown) with corresponding cams on its inner circumferential surface snaps into the notch 10, thereby ensuring an additional hold and, if necessary, a torsion resistance of the connection.

Figure 6 shows only a modified blind hole compared to the previous figures 3 to 5. Instead of of a truncated cone-shaped blind hole, a truncated pyramid-shaped blind hole 11 has been pressed into the pinch 2. The edges of the blind hole 11 are rounded in order to avoid tension in the pinch (not visible in the drawing). The narrow surfaces of the pinch 2 also have notches 10 here for a better base hold.

The depression shown in the pinch 2 of FIG. 7 is designed as a groove 12 in the side face that extends over the entire pinch width - ie also over the thickened central part 5. In order to avoid tension in the pinch 2, the groove 12 is slightly conical and rounded at the edges (not visible in the illustration). The second (rear) side surface also has a groove of the same type.

The pinch 2 of FIG. 8 is provided on each side surface with two depressions in the form of a T-groove 13. The horizontal sections of the T run closely to the edge of the thickened central part 5; however, this remains undeformed. Here too, the sharp edges of the T-groove 13 within the pinch 2 are preferably rounded. Similar to FIGS. 5 and 6, the two narrow sides have a recess 14 for a better base hold.

FIGS. 9 and 10 show an end of a fluorescent lamp provided with a lamp vessel melt according to the invention. The end face 7 is here provided with a shoulder 15 of smaller diameter which is arranged concentrically with the outside diameter, as a result of which the base to be put on later sits well centered. On a holder 16 there is an annular cap 17 surrounding the helix 8 appropriate. The holder 16 can be melted in the pinch 2 and end there or it is fused to the pump tube 4. After the lamp has been pumped and filled, the pump tube 4 is cut off gas-tight close to the pinch 2.

Different exemplary embodiments of a capped fluorescent lamp are shown in FIGS. In any case, it is assumed that the lamp vessel is crushed as described above. Sokkelung in Figure 11 is done in a conventional manner. A base sleeve 18 is provided with a base plate 20 containing the riveted base pins 19. The base is then fixed by means of cement 21 on the pinched lamp end.

The base 22 in FIG. 12 can be made from a plastic. On its inner circumferential surface it is provided with cams 23 with which it engages in the corresponding depression in the pinch 2, thereby ensuring an additional hold and the torsion resistance of the connection. In Figures 11 and 12, the power supplies with the socket pins are in a known manner - e.g. by terminals - electrically connected.

In FIG. 13, the base pins 24 have already been electrically connected to the power supply lines 3 before being crimped and then melted into the crimp 2 over part of their length. The cover cap 25 merely fulfills the function of mechanical protection for the pinch 2.

The fluorescent lamp in Figure 14 is provided with a glass base. Here, each is from the Quet Schung 2 led out power leads with their end back in an arc to the pinch 2, after which the resulting wire loops 26 are bent to one side of the pinch. Modified sockets are required for this type of fluorescent lamp base.

In a specific exemplary embodiment, a melting of a fluorescent lamp is described. The lamp vessel 1 consists of soda-lime glass and has an outer diameter D of approximately 25.5 mm. The length L of the pinch is approximately 6 mm and the width B or the thickness is approximately 20 mm or 3 mm. The pump tube 4 made of lead glass has an outer diameter of approx. 6 mm, as a result of which the thickened central part 5 increases to approx. 7 mm. In the border area of the pinch 2 to the thickened central part 5, a truncated cone-shaped blind hole 9 is pressed in on each of the side surfaces. The blind hole 9 has a largest diameter of approximately 2 mm and a depth of approximately 1.7 mm. In the event that grooves 12 or 13 are also provided instead of or in addition to the blind holes 9, these have a greatest width of approximately 2 mm and a depth of approximately 0.4 mm. The one-piece power supplies 3 melted into the pinch 2 have a coefficient of thermal expansion adapted to that of the glass. An oxidized or possibly boraxed iron-nickel-based wire is particularly suitable for the power supply.

Claims (16)

1. Electric lamp with a vessel melt formed as a pinch, in which a frame structure consisting of two power supply lines (3), between which a coil (8) is stretched, and possibly a holder (16) and a pump tube (4) , with one end of a tubular lamp vessel (1) made of glass, characterized in that the end face (7) closing the lamp vessel end essentially forms a plane and is arranged at right angles to the lateral surface of the lamp vessel (1), the transition of this the two surfaces to one another is essentially in the form of a circumferential edge, and that the length (L) of the pinch (2) arranged diametrically to the lamp vessel (1) and extending from the end face (7) in the lamp axis longitudinal axis is 0.2 to 0 , 4 times the outer diameter (D) of the lamp vessel (1) and the pinch width (B) is equal to or less than the outer diameter (D) of the lamp vessel (1). 2. Electric lamp according to claim 1, characterized in that the pinch (2) has a substantially rectangular cross section with a thickened central part (5). 3. Electric lamp according to claim 1 and 2, characterized in that the pinch width (B) forming side surfaces of the pinch diametrically arranged to the lamp vessel (1) arranged pinch (2) at least in the border area of the pinch glass to the thickened middle part surrounding the pump tube (4) (5) are provided with depressions (9, 11, 12, 13). 4. Electric lamp according to claim 1 to 3, characterized in that the depressions are designed as conical blind holes (9, 11), the depth of which is slightly more than half the pinch thickness. 5. Electric lamp according to claim 1 to 4, characterized in that the depressions (9) have a round shape. 6. Electric lamp according to claim 1 to 4, characterized in that the depressions (11) have a polygonal shape. 7. Electric lamp according to claim 1 to 3, characterized in that the depressions are designed as grooves (12, 13), the depth of which is less than a quarter of the pinch thickness. 8. Electric lamp according to claim 1 to 3 and 7, characterized in that the depressions run parallel to the longitudinal axis of the lamp. 9. Electric lamp according to claim 1 to 3 and 7, characterized in that the depressions (12) run at right angles to the longitudinal axis of the lamp. 10. Electric lamp according to claim 1 to 3 and 7 to 9, characterized in that the depressions (13) have parts extending parallel and at right angles to the longitudinal axis of the lamp. 11. Electric lamp according to claim 1 to 10, characterized in that the pinch (2) is provided with blind holes and grooves. 12. Electric lamp according to claim 1 to 11, characterized in that the lamp is a mercury vapor low-pressure discharge lamp with two lamp vessel ends. 13. Electric lamp according to claim 12, characterized in that the frame structure of at least one lamp vessel end is provided with a pump tube (4). 14. Electric lamp according to claim 12 and 13, characterized in that the frame structure of both lamp vessel ends is provided with a holder (16) which has a cap (17) shielding the filament (8). 15. An apparatus for producing an electric lamp according to claim _. 1 to 14, characterized in that the gas pressure in the squeezed and still partially softened lamp vessel (1) can be changed. 16. A method for producing an electric lamp according to claim 1 to 15, characterized in that essentially the following operations are carried out: a) Holding the lamp vessel (1) in relation to the pinch jaws b) inserting the frame structure into the lamp vessel end to be melted down c) heating the lamp vessel end to be melted to the softening temperature of the glass d) Execution of the squeezing process, with immit Telbaren connection to the crushing process with still softened glass and still closed jaws a certain gas pressure (P) on the inside of the lamp vessel - for example via the pump tube - is exerted, whereby the lamp vessel end receives the final shape given by the squeeze jaws.

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