US2183198A

US2183198A - Mercury switch

Info

Publication number: US2183198A
Application number: US147093A
Authority: US
Inventors: Lindstrom Alrik Civer
Original assignee: Individual
Current assignee: Individual
Priority date: 1936-06-13
Filing date: 1937-06-08
Publication date: 1939-12-12
Anticipated expiration: 1956-12-12
Also published as: FR822996A; NL46464C; BE422062A; GB496961A; DE693719C

Description

Dec. 12, 1939. c, mns zj v 2,183,198

MERCURY SWITCH Filed June 8, 1937 Patented Dec. 12, 1939 e MERJCURYSWITCH v Alrilr Giver Lindstriim, Stockholm, Sweden Application June a, 1931, Serial No. 147,093 Sweden June 13, 1936 50laims. (oi. 200-152) The present invention relates to mercury switches of the type comprising a closed receptacle partly filled with mercury, and solid metallic electrodes therein, said electrodes being adapted to be connected in an outer circuit and,

inthe closed position of the'switch, to be connected with' each other within the receptacle by direct metallic' gcontact formed by the mercury.

Onefobject of the invention is to provide an improved mercuryswitch of the type described, in which impurities disengaged from the solid electrodes due to the action of the electric arc orgoii mercury 'vapor are "prevented from passing tion of the switch, in which the contactgs and breakings are, performed, thus.

maintaining the surface of the mercury in said section clean, whereby the arc remains easy-to break and excessive heating is prevented even 7' after the switch "has been used for a long period.

Another object of the invention is to prevent the arc and the mercury vapor from coming into contact with the solid electrodes so as to reduce or eliminate the disengagement of impurities from the latter and to decrease the intermediate resistance between the electrodes and the mer-' as mercury filling-openings duringthe assembly I cury.

A further object of theinvention is to pro vide a mercury switch of the type described, in which the electrodes are screened oil from the free mercury surface in the section of the receptacle, where the contact makings and breakings are performed, in such a manner that the L passage of particles disengaged from the electrodes to said mercury surface is prevented or made more difllcult.

Still another object of the invention is to provide a switch of the type described having two partitions protruding into the mercury between .the electrodes and separating the parts of the free mercury surface located above or at the Y electrodes from the parts of said surface located merely with mercury vapor. Provided cenin the space where the contact is made or broken, in order to retain the impurities on the firstmentioned parts of the mercury surface and to' prevent them from moving therefrom.

A still further object is to arrange said partitions in such a manner that a so called mercury trap is formed, by which the gas-fllledspaces near the electrodes are separated from the remaining gas-filled spaces. v A preferred embodiment of the switch according to the invention will be described hereinafter with reference to the accompanying drawing, in

i which Figures 1 and 2 are two sectional elevations ,at right angles to each other, the section accordbetween for tightening purposes.

tres the caps l2 and i3 are pressed out to form-' ing to .Fig. 2 being taken along theline 22 in Fi 1. v

In the drawing, I designates a base plate and 2, 3 two resilient arms attached thereto. The

mercury switch proper is rotatably supported by V 5 these arms which by their outer ends embrace hollow pivots 6 and l on the switch. The arms tubular part being closed by caps 12 and It of any suitable metal, for instance iron orsteel. The caps are joined to the tubular part by a go molded mass M, for instance an artificial resin, asbestos rings I5 and It being interposed there- At theirlcenshort open sleeves" and I8 respectively, serving of the switch. The above-mentioned hollow piv ots 6 and I embrace these sleeves andare soldered thereto. Preferably, the pivots are made of a highly conductive metal, as'for instance brass, 80

with a viewto ensure a good electrical contact with the arms land 3. Insulating washers l9 are interposed between the sleeves and the brass pivots to prevent thetlatter from being attacked by the mercury. 1

The receptacle thus formed is partly fllled' Y with a mercury mass 20, adapted to form metallic contact between the two electrodes of the switch, namely the caps l2 and I I. The space ortne receptacle above the mercury level may be filled 40 with a suitable gas, for instance hydrogen, or

trally of the receptacle is a wall 2| of insulating material, preferably made integral with the tubular part II and having an aperture 22 located eccentrically in relation; to the axis of rotation of the switch so as to be wholly above the'-mer-. cury level in the one end position of the switch and immersed in'the mercury, whenthe switch is rocked to its opposite endposition. Thus, in

the one end position the mercury mass is divided by the "wall 2| into two separate halves and' the electrical connection is broken, whereas .in the other endpositioh of the switch theaperture r a: is filledwith mercury, that the whole of me at mercury mass constitutes a coherent unit and forms a metallic connection between the electrodes l2 and I3.

. Provided at each end of the tubular part II is an

additional wall

23 and 24, respectively, of electrically insulating material, for instance porcelain, said walls fitting into recesses provided on the inner surface of the part II and joined thereto in a gas-tight fashion. At their bottom the

walls

23 and 24 have

apertures

25 and 26, respectively, which are immersed in the mercury in all positions of the switch, so that the mercury masses at both sides of the walls are electrically connected at all times. Thereby in the operation of the switch impurities originating from the electrodes I2 and I3 and collected on the

outer surfaces

21 and 28 of the mercury are prevented from passing into the central space, where the contact makings and breakings take place. On account of the walls completely separating the spaces above the mercury level from each other, the electric arc is prevented from reaching. the solid metal electrodes l2 and I3. Due to the restricted cross-sectional area of the

apertures

25 and 26 it is difllcult for the mercury vapor to find its way to the electrodes through the mercury.

The embodiment described and shown in the drawing is to be considered only as an illustration of the principle of the invention and is not restrictive of its scope, as modifications in several respects are possible without departing from the inventive idea as. set forth in the appended claims.

What I claim is: l. A mercury switch, comprising a closed receptacle mounted for rocking movement between two end positions, two electrodes in said receptacle, a mercury mass in same in contact with said electrodes, an insulating wall between said electrodes rigidly connected with the receptacle, an aperture in said wall adapted on the rocking movement of the receptacle to be located above the mercury level in one end position of the switch and under the mercury level in the other end position of the switch, an insulating wall between each of the electrodes and the firstmentioned wall, apertures in the last-mentioned Wallslocated under the mercury. level in both end positions of the switch..

2. A mercury switch comprising two metal electrodes, a mercury mass in contact with said electrodes to connect and disconnect the same, an apertured insulating wall between said electrodes to make and break-the connection between same on rotation of the switch, an insulating wall between each of the electrodes and the first-mentioned wall, the last-mentioned walls being provided with apertures simultaneously immersed in the mercury mass.

3. A mercury switch, comprising a sealed receptacle mounted for rocking movements. twosulating body, metal caps'closing the ends of said body, an apertured insulating disk located at the centre of said tubular body and lateral insulating disks located to both sides of the first-mentioned disk and having apertures, said apertures being located on the same side of the axis of the tubular body, and means limiting the rocking movement of the receptacle.

5. A mercury switch comprising a receptacle consisting of a cylindrical insulating body mounted for rocking movement aboutits axis, means limiting the angle of said rocking movement, two

metal electrodes one at each end of said body, a

mercury mass adapted to connect and disconnect said electrodes, means adapted to separate and permit coalescence of the mercury mass during the rocking movements of the receptacle, insulating disks located between said electrodes one at each end of said cylindrical body, said d sks being provided with apertures located on the same side of the axis of said cylindrical body.

ALRIK CIVER LINDSTRCSM.