DE444430C - Gas-filled electric light tubes - Google Patents

Description

To with gas-filled electric fluorescent tubes without to. extensive increase in The attempt has already been made to achieve a large, luminous surface a glass body (for example a glass tube), which reduces the interior of the tube. Both known arrangements, however, make the production and insertion of the inner body great difficulties that place high demands on the art of glassblowing, especially the inserted body carries wire leads and electrodes.

In the case of the electric fluorescent tube forming the invention, the existing ones are now Defects eliminated in the simplest way that between the two electrodes The actual fluorescent tube is also loosely inserted if a tubular glass body is, whose diameter is expediently chosen so that that between the two Tubes remaining ring cross-section is about as large as the cross-section of the previous one usual fluorescent tubes. Around the loosely inserted insert tube at a sufficient distance To keep from the inner wall of the arc tube, radially arranged tips are arranged on it. An axial shift the insert tube is through the two protruding into the ends of the fluorescent tube Electrodes prevented.

In the “drawing, such a fluorescent tube is shown in two exemplary embodiments”.

Fig. R is a view of a fluorescent tube of the previously common design. In

Fig. 2 shows a light tube according to the invention in longitudinal section, and

Fig. 3 shows, on a larger scale, a longitudinal section of another embodiment the fluorescent tube.

In the known fluorescent tube according to Fig. Ι

λ denotes the electrodes housed in the two pipe sockets b , c is the light tube of relatively small diameter.

It is well known that the diameter of the fluorescent tube cannot go beyond a certain level, because otherwise the power consumption would exceed the limits of economic efficiency. Since the tube cross-section and power consumption are in a certain relationship to one another, one must endeavor to keep the former as small as possible and still achieve a large luminous effect. This is achieved with the subject of the invention, as shown in Figs. 2 and 3 of the drawing, that between the two electrodes of a fluorescent tube - a relatively large diameter a second, fused tube e is loosely inserted so that between Both a ring cross-section is created, which corresponds to the usual light tube cross-section. In the first embodiment (Fig. 2) provide in a ring / used in or with the glass of the insertion tube e fused Spitzeng · ensure that the insertion tube e obtains the correct distance from the inner wall of the arc tube ^, while a longitudinal displacement of the insertion tube through the two electrodes α of the fluorescent tube is prevented. In the second embodiment (Fig. 3) extends obliquely standing peaks based h of the insertion tube against constrictions e / d of the arc tube and thereby haiten the insertion tube e both in the radial and in the axial direction non-displaceably fixed.

To increase the luminosity, the insert tube e can also be given a reflective coating in a manner known per se.

Claims (3)

Patent claims: 1. Gas-filled electric fluorescent tube, inside which a glass tube closed at both ends is arranged to reduce its volume, characterized in that the insert tube (e) between the two electrodes (a) of the fluorescent tube (d) is loosely inserted. 2. fluorescent tube according to claim 1, characterized in that as a safeguard against radial displacement of the insert tubes {e) at their ends radially standing tips (g) are attached, while their axial displacement through the two electrodes (0) of the fluorescent tube (d) is prevented. 3. fluorescent tube according to claim 1, characterized by on the insert tube (e) attached tips inclined in the axial and radial direction and supported against constrictions (i) of the fluorescent tube (d) \ h). FigJ Ct cc Fig. L cc Abbr Ot