US1844402A

US1844402A - Means for operating mercury switches

Info

Publication number: US1844402A
Application number: US198612A
Authority: US
Inventors: Leblanc Maurice Auguste Eugene
Original assignee: General Electric Vapor Lamp Co
Current assignee: General Electric Vapor Lamp Co
Priority date: 1926-06-22
Filing date: 1927-06-13
Publication date: 1932-02-09
Anticipated expiration: 1949-02-09
Also published as: FR620374A; GB273257A; DE481294C

Description

2- M. A. E. LEBLANC 1,844,402

MEANS FOR OPERATING MERCURY SWITCHES Filed June 13. 1927 INVENTOR BY v I ATTORNEY Patented Feb. 9, 1932 warren i MAURICE aoo'os'rn EUGENE TLTELA C, 01? SUEESNE$, ZRATLQ'QE, AESIGNOR, BY IKESNE ASSIGNMENTS, T ELMLEEIC VAPQR. COMPIiNY, -01 HOBOKEN, NEW JERSEY, A CORPORATIGN (03F ItlE'tiV JERSEY MEANS F03 QL ERATING MERCURY Application filed June 33, 1927, Serial No. 198,612, and in France June 23, 1928.

- ture in which'causes bending, this latter phenomenon being employed to produce tilting of the switch, thus causing therein movements of the mercury necessary for its operation.

Electric switches with mercury contacts in a neutral gas have not hitherto received all the applications in electrical apparatus which their great simplicity and great surcness of operation merit. This is due to the fact that this latter requires slow displacements of fairly large amplitude which it is not always easy to realize with the ordinary electromagnetic relays.

The same thing may be said of compound strips or thermoelectric elements by which is meant an aggregate of two metallic strips soldered together over the whole extent of one surface of each of them, the metals constituting the two strips being selected with coefficients of expansion as different aspossible.

Under these conditions any change of temperature in the bi-metallic strip is shown by a change of curvature. This change of shape has already been used to close or to open electric contacts, but the weakness of the mechanical forces, which come into play generally necessitates somewhat considerable complications to ensure perfect operation.

The construction of mercury switches employed in carrying the invention into practice may be any whatever.

Fig. 1 shows an arrangement in which there is a rigid attachment between a iii-metallic strip K and a mercury switch L. The bimetallic strip K, which is located vertically when at rest and rigidly fixed at its upper end M, carries at its lower end a horizontal bar 0 to which are attached the grips holding said switch L. The terminals of the latter as well as he free end of the bi-inetallic strip are connected by flexible leads to fixed terminals N. While there has been shown as an example the case of a reversing switch hang from a bimetallic strip heated by its own resistance, it is to he understood that with this arrangement there may be employed any type of mercury switch and that any of the usual means of heating the bi-metallic strip may be employed.

The sensitiveness of the device may be increased by compensating for the weight of the mercury switch by immersing it in a liquid having a density approximating its mean density as Sll0, 'n in Fig. 2; this arrangement has the advantage of damping the oscillations caused by external vibrations.

Claims: 1. In combination, a mercury switch and a liquid bath surrounding said switch, said bath having a density substantially equal to the average density of said switch.

2. in combination, a mercury switch, a thermo-sensitive element supporting said switch, and a liquid bath surrounding said switch having a density substantially equal to the density of the switch.

In testimony whereof I afiix my signature.

PJAURHCE AUGUSTE EUGENE LEBLANC.