US1600595A - Electrode for luminescent tubes - Google Patents

Description

' Sept. 21 I926.

' r 1,600,595 P. F. J. LEBRUN ELECTRODE FOR LUMINESCENT TUBES Filed Spt. s, 1925 Inventor Pazdj ZLJeZ/zzn Attorney Patented Sept. 21, 1926;

UNITED STATES,

PATENT OFFICE.

PAUL FRANCOIS JOSEPH LEIBBUN, OF PARIS, FRANCE, ASSIGNOB OI ONE-HALF '1'0 MAURICE JULES QUEDBUE, OF MONTREAL, CANADA.

ELECTRODE FbB LUMINEBCENT TUBES.

Application filed September 8, 1825. Serial No. 55,102.

The present invention pertains to a novel lamp for luminescent tubes employed in themanufacture of luminescent-signs consisting of a suitably bent glass tube filled with a conducting gas and having an electrode ateach end.

The object of the invention is the provision of a device designed for application to the ends of a luminous tube and containing the electrode. I

The device comprises a; bulb wh1ch is completely sealed except where' 1t is connected to the luminescent tube. The electrode contained within the bulb consists of a pair of metallic plates which intersect with one another and are connected to conductors passing through the wall of the tube and adapted to receive current from a convenient source.

A particular feature of the invention is that the plates are bent s1nuously, preferably being substantially S-shaped 1n cross section. This construction affords a lar er electrode area for a given size of cham er thanwould be possible if the plates were merely flat. The increased surface of the electrode provides a more intimate contact between the current and the gas within the bulb and allows more ra id dissipation of the heat of resistance. he plates are insulated from the bulb by means of balls received in apertures formed in the plates.

The invention is fully disclosed in the following description and in the accompanying drawings in which Figure 1 is a longitudinal section of the electrode showing the interior parts in elevation;

Figure 2 is a cross section of the electrode on the line 2'-2 of Figure 1; and

Figures 3 and 4 are perspective views of the conducting lates.

Reference .to t ese views will now be made by use of like characters which are employed I to designate corresponding parts throughout.

The electrode comprises a bulb 1 connected or adapted for connection at one end to a luminescent tube 2 of a displa sign.

Luminescent tube signs are alrea y well.

known in the art and are constructed by bending a glass tube into the script or design to be displayed. The tube is filled with a gas such as argon, helium or neon and isprovided with a lamp or electrode at each end. When current is applied to the lamps or electrodes, it' also fiowsthrough the gas in the curved tube and produces a luminous colour which is determined by the nature of the gas contained within thetube.

According to this invention the electrode contained with the bulb .1 comprises a palr of plates 3 each having a slot 4 extending from the midpoint of one edge perpendicularly to the centre of the late. The plates are then fitted to ether by means of the slots so that the s otof each plate lies in alinement with the slot in the other plate, whereby the height of the assembly is equal to the height of each plate.

The. ends of each plate lying parallel to the alined slots are curved in opposite directions as indicated by the numerals 5 and 6 in Figure 2. -The intermediate portion of each plate is allowed to remain plates have apertures 11 in their corners adapted to receive spacing balls 12 consistlng of glass, quartz or other vitreous material. The balls are now placed in the apertures and the'electrode is inserted within I the bulb 1. The balls bear against .the inner wall of the bulb and thereby hold the electrode spaced and insulated from the bulb. 7

The ends 13 of the conductors are now' passed around'the open' end of the bulb and secured to the outer wall thereof. A jet or torch is applied to the free edge of the bulb in order to form an interior tube 14 which at the same time is welded to the bushing 10. Finally, a plu 15 is applied over this .end of the tube an secured to the ends 13 of the conductors 8. The plug is of such shape that it may be inserted in an appropriate socket to receive current therefrom.

The plates 3 may consist of any suitable metal and their thickness may be determined according to particular requirements. The

material of which the plates are made is preferably extra pure sheet iron. The curvature of the plates provides a greater discharge of surface for a bulb of a given size than is ossible with merely flat plates. A better istribution of current within the bulb and consequently a more intimate contact between the current and the conducting gas is thus obtained. A further advantage of the larger surface of the plates is that the heat of resistance is more rapidly dissipated whereby the lamp is less likely to become overheated.

It has been found in practice that an electrode constructed in this manner has a life of 10,000 hours or more. At the end of this period the electrode is recharged with gas.

While a specific embodiment of the invention has been illustrated and described, it is to be understood that various alterations in the details of construction may be made without departing from the spirit of the illvention as indicated by the appended claims.

Having thus fully described the invention,

what I claim as new and desire to protect by Letters Patent is 1. An electrode for luminescent tubes comprising a bulb adapted for communication with a. luminescent tube, a pair of intersecting conducting plates contained in the bulb and spaced from the walls thereof, said plates being sinuously bent, a current conductor connected to said plates, said bulb being completely sealed except Where .it'communicates with the luminescent tube.

2. An electrode for luminescent tubes comprising a bulb adapted for communication with a luminescent tube, a pair of intersecting conducting plates contained in the bulb and spaced from the walls thereof, said plates being substantially S-shaped in cross section, a current conductor connected to said plates, said bulb being completely sealed except where it con'nnunicates with the luminescent tube.

In witness whereof I have hereunto set my hand.

PAUL FRANCOIS JOSEPH LEBRUN.

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