US1861566A - Switching device - Google Patents

Description

June 7, 1932. c. HATAY SWiTCI-IING DEVICE Filed May 1, 1929 Inventor. m b3 HisAttorne g.

Patented June 7, 1932 UNITED STATES PATENT orrlca CHARLES HA TAY, OF BELIEF-CHARLOTTENBURG, GERMAIIY, ASSIGNOR '.[0 GENERAL ELECTRIC COMPANY, CORPORATION OF NEW YORK SWITCHING DEVICE I Application filed Kay 1, 1929, Serial No. 859,651, and in Germany May'7, 1828.

My invention refers to switching devices and more especially to a mercury switch. It is an object of my invention to provide means whereby the life' of such switches is prolonged.

In the mercury switch, tubes of the prior art the arc iormed during the switching operation. gradually causes erosion of the glass walls 'so that finally cracks and fissures will form in the glass which may lead to destruction of the tube. Even before these condi-' tions have arisen small glass particles split ofi the walls and float on the surface of the mercury, giving rise to undesirable disturbances.

It has alreadybeen suggested that these drawbacks might'be obviated by replacing the glass tubes by quartz tubes, but the high price of the latter rendered this suggestion impractical for commercial purposes.

ccording to the present invention the drawbacks aforementioned are obviated by providing the glass tube with a lining of highly resistive material. The term highly resistive material as used in' this specification and the claims appended to it is intended to include particularly resistive kinds of glass as Well as quartz and other similar matcrials." This lining need not cover theentire inner surface of the tube but may extend only over part of the surface. Preferably instead of a lining firmly adhering to the lass tube, a vessel maybe loosely inserted in the,tube. As compared with a tubular in sert open at both endsa vessel closed at one end offers the advantage of reventing the passage of mercury between t e wall of the tube and the vessel and the entrance of mercury into the vessel from the rear side. In addition a vessel closed at one end can easily be fixed in its correct position by means ofv the electrodes without any particular fixing means being required. 4

In the drawing aflixed to the specification and forming part thereof, several devices embodying my invention are illustrated diagrammatically by way of example.

In the drawing:

Fig. 1 is a mercury switch tube with a quartz or other vessel inserted therein, this vessel being formed substantially similar to the part ofthe tube in which it is arranged.

Figs. 2 and 3 are axial sections illustrating two other forms of vessels and Fig. 4 is an elevation of another mercury switch tube with a fourth form of a vessel inserted therein.

Referring first to Fig. 1, 1 is the glass tube closed at one end by a round bottom and 2 is a vessel consisting of quartz or of a particularly resistive kind of glass and having a bottom rounded to fit into the bottom portion ofthe glass tube, the other end of the vessel being open. 3 and 4 are the two electrodes, which are bent in such fashion that they keep the vessel fixed in the bottom portion of the tube.

It is obvious, however, that if the switch tube shown in Fig. 1 is tilted through an unduly great angle, all the mercury will escape from the vessel 2, resulting in an are between the mercury and the electrode 4. A vessel such as illustrated in Fig. 2, which will prevent the escape of all the mercury, is therefore preferred. This vesselis formed with a constricted portion 5 extending circumferentially around the vessel between the elec-, trodes 3 and 4, so that even if this vessel is tilted through a considerable angle, sbme mercury will nevertheless be leftin the bottom portion of the vessel.

In the modification illustrated in Fig. 3 the constriction 5fshown inFig. 2'is're placed by a mere indenture 6 serving the same purpose. Obviousl this form of avessel can be manufacture at a lower price, but means must here be provided for preventing angular displacement of the vessel in the tube.

In the switch illustrated in Fig. 4 the danger that the inner electrode 4 might be left without any mercury is prevented, since the vessel] is formed with an inwardly directed tubular flange or reentrant portion 8 which. always retains an appreciable amount of mercury. The electrode 9 extendsinto the vessel and is bent, so that its end extends into the pool of mercury retained between the outer wall of the vessel 7 and the reentrant portion 8. Obviously with this form of the lining vessel the-free end of the electrode 9 will always be immersed in mercury.

. I wish it to be understood that I do not I desire to be limited to the exact details of Ill) construction shown and described for obvious modifications will occur to a person skilled in the art. a

I claim 1. A mercury switch comprisin a sealed tube containing mercu into said tube, and a lining of highly resistive material within said tube, said hning having a pocket therein which cooperates with the remainder of said lining to retain a pool of mercury in said lining at all positions of said switch, one of said electrodes terminating in said mercury pool at all operative positions of said switch.

2. A mercury switch comprisin a sealed tube containing mercu electro es sealed therein, and a linin of ighly resistive material within said tu said lining being cupsha ed with a reentrant rim, whereby .a. K00 of said mercury is retained within said 'ning at all positions of said switch, one of said electrodes terminatingin said pool of mercury.

'In testimony whereof I afiix m signature.

CHARLES ATAY.

ry, electro es sealed

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