JPS6326928Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tube having a screw cap at the end of the glass bulb.

The structure generally adopted for adhering screw caps to the ends of glass bulbs of incandescent light bulbs and high-pressure discharge lamps is to form the outer peripheral surface of the end of the glass bulb into a spiral shape during the sealing process of the glass bulb. At the same time, a groove for conducting one of the pair of external lead-in wires led out from the end of the glass bulb is formed along the tube axis direction on the outer peripheral surface of the end of the glass bulb,
After attaching the cap to the end of the glass bulb, solder the external lead-in wire led out from the groove to the opening of the cap.
The other external lead-in wire is soldered to the central conductive part of the cap.

In such a structure, for example, as in the case of a normal incandescent light bulb, the two external lead-in wires led out from the end of the glass bulb are structurally and functionally identical, and there is no need to distinguish between the two. Sometimes there is no problem, but for example, in the case of pulse-starting high-pressure discharge lamps, in order to lower the discharge starting voltage of the lamp as much as possible, the electrode located on the base side of the pair of electrodes of the discharge lamp arc tube. When it is necessary to distinguish between external lead-in wires, such as when connecting an external lead-in wire connected to There was a drawback that the two external lead-in wires crossed and touched each other. The reason why such a problem occurs is that when sealing the glass bulb and stem using a rotary sealing machine, the groove on the surface of the glass bulb does not necessarily have to be inserted into the groove at the molding position of the end of the glass bulb. This is because the grooves are not necessarily formed on the external lead-in line side, and in some cases, the grooves may be formed near the opposite side.

The present invention has been made to eliminate the above-mentioned conventional drawbacks, and one embodiment thereof will be described below with reference to the drawings.

1 and 2 are sectional views of essential parts of a high-pressure discharge lamp according to the present invention, respectively.

In FIGS. 1 and 2, reference numeral 1 denotes a glass bulb, the end of which is sealed with a stem 2, and external lead-in wires 3, 4 are led out from this end.
The external lead-in line 3 is connected inside the glass bulb 1 to the base end of the arc tube (not shown). The outer circumferential surface of the end of the glass bulb 1 is formed into a spiral shape so that the screw-type cap 5 can be attached while being twisted, and the external lead-in wire 3 is inserted through the end of the glass bulb 1 along this axial direction. Two grooves 6 and 7 are provided for this purpose. Note that the number of grooves can be changed to 3 as necessary.
It is also possible to have more than one. By providing a plurality of grooves 6 and 7 in this manner, no matter how the grooves are positioned with respect to the external lead-in wire 3 during sealing molding of the glass bulb 1 and the stem 2, it is possible to By using the closer groove, cross-contact between the external lead-in wires 3 and 4 inside the cap 5 can be completely prevented. In the figure, the end of the external lead-in wire 3 is connected and fixed to the opening of the cap 5 with solder 8 to prevent the cap from loosening during use. When solder is poured into the cap opening, there is also the advantage that the adhesive strength between the cap 5 and the glass bulb 1 becomes even stronger.

Although the above embodiment is an example of a high-pressure discharge lamp, the present invention can also be implemented with an incandescent lamp. That is, for example, in an incandescent light bulb that has a structure in which one of the external lead-in wires also serves as a fuse, the present invention is useful because it is preferable to connect this external lead-in wire to the central conductive part of the base. .

As explained above, the present invention has excellent features such as easily preventing cross-contact between the external lead-in wires in the cap by providing multiple grooves for the external lead-in wires on the outer peripheral surface of the end of the glass bulb. This makes it possible to provide an effective tube.

[Brief explanation of the drawing]

FIG. 1 is a front cross-sectional view showing the main parts of a tube according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the tube taken in a direction perpendicular to the tube axis. 1... Glass bulb, 2... Stem, 3, 4... External lead-in wire, 5... Cap.

Claims (1)

[Scope of utility model registration request] A groove is provided along the axial direction of the end of the glass bulb whose outer peripheral surface is formed into a spiral shape, and an external lead-in wire led out from the end of the glass bulb is inserted into this shaft, and the end of the glass bulb is provided with a groove along the axial direction. A tube comprising a screw-type cap that is attached while being twisted and the external lead-in wire is connected to the cap, the tube being provided with a plurality of the grooves for inserting the external lead-in wire. ball.