US1845837A

US1845837A - Electrode structure for electrical discharge tubes

Info

Publication number: US1845837A
Application number: US243653A
Authority: US
Inventors: William F Hendry
Original assignee: MANHATTAN ELECTRICAL SUPPLY CO
Current assignee: MANHATTAN ELECTRICAL SUPPLY CO; MANHATTAN ELECTRICAL SUPPLY COMPANY Inc
Priority date: 1927-12-30
Filing date: 1927-12-30
Publication date: 1932-02-16
Anticipated expiration: 1949-02-16

Description

Feb. 16, 1932. w. F. HENDRY ELECTRODE STRUCTURE FOR ELECTRICAL DISCHARGE TUBES Filed Dec. 30. 1927 INYEN'TOR w. 2 H1 Ill Patented Feb. 10, 1932 UNITED STATES PATENT OFFICE wILm II. HENDBY, OF OBSDTING, NEW YORK, ASSIGNOB, BY MEBNE ASSIGNKENTQ, TO KANHA'ITAN ELECTRICAL SUPPLY COMPANY, INC., OF JERSEY CITY, NEW JERSEY, A CORPORATION 01 NEW JERSEY ELECTRODE STRUCTURE FOR ELECTRICAL DISCHARGE TUBES Application m December :0, m1. lerlal Io. 243,053.

This invention relates to electrode structures for electrical discharge tubes and per tains more particularly to electrodes of the general type disclosed in my Patent No. 1,628,045 and copending application Serial No. 180,788, filed April 4, 1927.

In the above mentioned application is disclosed an improved form of electrode structure for an electrical discharge tube of the illuminating type. This electrode structure which consists of a point electrode surrounded by a sleeve of insulating material spaced a slight distance therefrom, has been found to be very satisfactory in most respects. However, it is necessary carefully to degasify the entire electrode assembly before putting it into use in a discharge tube. As there is quite a large amount of insulating material in the assembly and this insulating material contains a large quantity of absorbed gases, degasification is accomplished only a ter a relatively long treatment. Furthermore, in order to obtain the accurate dimensions desirable for the parts used in the making of such electrode structures it is necessary, for best results, to use special insulating material which can be reduced to accurate dimensions.

It is an object of my invention in order to avoid the use of large amounts of insulating material, to provide an improved electrode structure wherein a specially constructed metal sleeve is used in place of the insulating sleeves disclosed in the above mentioned application and patent. In accordance with my present invention, I hold this sleeve in its proper position by insulatingmeans which ma be in the form of small locks of any desirable insulating material, such as porcelain or Lavite, moulded or otherwise fashioned to the desired shape. This construction reduces the amount of insulating ma terial to a minimum and hence reduces the length of time necessary for the degasification of the electrode structure, while at the same time providin a structure readily adaptable to mass pro uction in a cheap and manner.

order that the invention me be fully understood I have illustrated in e accompanying drawings, and described hereinafter, a preferred embodiment thereof.

In the drawings, Fig. 1 illustrates an electrical discharge tube having positioned therein an electro e structure constructed in accordance with my invention.

Fig. 2 illustrates a modified form of electrical discharge tube having a similar electrode structure therein.

Fig. 3 is a view taken along section lines 33 of Fig. 2.

Fig. 4 shows in perspective one of the block insulators used in the electrode structure.

Reference numeral 1 indicates an electrode which ma be of any desired conducting material sucli as aluminum, copper, carbon or the like having a rod like extension or base 8 and surrounded by a metallic sleeve of conducting material 2. This metallic sleeve has an extension tube 5 which is divided lon itudinally by means of slits 16 into a plurality of segments 17 ,each having therein an 0 ening 6 for receiving an insulating bloc 7. The block 7 may be constructed of any desired insulating material such as porcelain, Lavite or similar material, molded or otherwise fashioned tothe desired sha e. The insulating blocks bear a ainst ro -like extension 8 of electrode 1. he blocks are pressed firmly against the rod 8 by the se cuts 17 of extension tube 5 of sleeve 2 which extension is made of sufliciently resilient material to insure proper alignment, through the agency of the insulating plugs, relative to the rod 8. With this arrangement it is very easy to slide the sleeve relative to the rod and ac tive portion to secure the proper positioning thereof.

Placed around the sleeve 2 for preventing any discharge from flashin back around the lead-in wire of the electro e, and for centering the electrode structure in the discharge tube, is a flange 4 which has a shoulder 3 for holding the ange in position around the sleeve. In order to prevent longitudinal displacement of the flange 4 with respect to the sleeve 2, the shoulder 3 of flange 4, and the sleeve 2 are fastened together in some suitable manner, such as by deformation 9. As disclosed in my aforementioned patent the sleeve lon enough to give a good bearing.

. 13 having an upwa e entlre electrode assembly is positioned within one end of a discharge tube 10 and is held in its proper position by a deformation 11 in the wall of the tube, with which the flange 4 of the sleeve 2 contacts. The electrode structure is prevented from movement in a backward direction by means of a tubular extension 12 which forms an inwardly.

turned portion'of the envelope of the tube and which surrounds the back end of the rod 8, the inner end of the tube 12 contacting with the ends of insulating blocks 7. The construction'of the insulating blocks is disclosed more in detail in Fig.4 wherein it willbe noted that the blocks consist of an elongated portion rdly projecting shoulder 14 which passes through one of the o nings 6 in the tube 5, the inner face 15 of t e elongated portion 13 being curved to conformto the curvature of therod 8.

The electrode structure illustrated in' Fig. 2 is exactly the same as that shown in Fig. 1, it being positioned within a tube 18 in sli t-ly different manner than in the tube 10. the tube of this figure the electrode structure is held in its proper position by a lead-in wire 19 which serves to hold the flange 4 of the sleeve 2 against a packing of glass wool 20 which in turn bears against shoulder 21 of the tube 18. As set forth in m above mentioned application, the glass woo serves to conduct heat from the electrode structure and thus insure the more eflicient operation of the tube. While I have illustrated the sleeve 2 and flange 4 as bein separate pieces, it will be understood that t ey might likewise be made of a single unitary piece, or the sleeve and flange might be made unitary and fashioned to form a telescope joint with the extension tube 5. The sleeve 2 might, if desirable, be used alone without the flange 4. Instead of having three insulating blocks as shown, a different number might be used, and while it is preferable to use blocks having shoulders projectinfg through openings cut in the extension 5 o the sleeve 2, other constructions might be used, for example, a split cylinder of insulating material might be laced inside of the extension tube 5. I reer to construct the sleeve and flange of s eet material, by punching, for example, but in some cases it might be found advantageous,

for structural reasons, to utilize a sleeve of heavy material, die cast or machined to the correctdimensions. In such a case, the extension tube 5 might be made a separate piece and be telescoped with the sleeve for a portion of its length.

his

from the spirit of the invention as set forth in the following claims.

WhatI claim is:

1. In an electrode structure for an electrical discharge device, an electrode havin an active portion and a base portion and a s eeve of con ucting material surrounding said active portion and se arated a-slight distance therefrom to provi e a free space, said sleeve being spaced rom said base rtionb a lurality of radially disposed b ock like ms ating means placed between the said base portion and the inside of said sleeve.

2. In an electrode structure'for an electrical dischar device, an electrode having an active portion, a base portion, and a metallic sleeve surrounding said active portion at a slight distance therefrom, said sleeve being cut to provide segments, said segments having openings therein, and insulating means cooperating with said segments and openings for holding said sleeve in its proper position.

3. In an electrode structure for an electrical discharge device, an electrode structure comprising an electrode, a metallic sleeve surrounding said electrode at a slight distance therefrom, said sleeve having cuts at one end dividing said sleeve into segments, and insulating means positioned between said sleeve and said electrode in such fashion as to be resilientlly gripped by said segments and to hold sai s eeve in its proper alignment.

4. An electrode structure for an electrical discharge tube comprising an electrode, and a sleeve having resilient se ents, said sleeve surroundin said electr e and be spaced and held in alignment by means 0 insulators placed between. said segments and said electrode.

5. In an electrode structure for an electrical dischar device, an electrode-having an active portion, a base portion and a metallic sleeve surrounding said active portion at a slight distance therefrom, said sleeve being cut to provide segments, and insulating means cooperating with said segments for holding said sleeve in its proper position.

6. An electrode structure as set forth in claim 5, wherein means is provided forpreventing dis lacement of the said insulating means relative to the said sleeve.

7. In an electrode structure for an electrical discharge device, an electrode having an active portion and a base portion and a sleeve of conducting material surrounding said active portion and separated a slight distance therefrom to provide a free space, said materially conductive sleeve being electrically cember 1927.

WILLIAM F. IENDRY.