US2012491A - Relay - Google Patents

Description

ug. 27, 1935. N, F, AGNEW 2,012,491

RELAY Filed Sept. 7, 1954 Fig. .5. l. INVENTOR Norman F Agnew.

BY WMM Y HIS ATTORNEY Patented Aug. 27, 1935 UNITED STATES PATENT OFFICE Union S Swissvale, Pa., elkaar to The tch & Signal Company, Swlssvale,

Pa., a corporation of Pennsylvania n September 7, 1934, inizi No 743,87

2 Claims. (Cl. 20G-422i My invention relates to reiays and particularly to relays of the type heim a conducting'flquid fcrmaki'ng and breaking mints.

l will describe severa! forma-ot Rhys enodymgmmvention,and'willmenpomtnthe novel iatures thereoil in claims;

In the aecomplmins Figs. 1 and 2 are ditic views otr'two forms ol relays each embodying my invention. Fig. 3 is odialb grammatic view of a modification of a portion. of the relay shown in Fic. hand also-embodying myinvention. FigAisapianviewofl form ot relay also i my invention, and Figisasectionalviewefig alongthe line 15" 5-5- reference charaotersreter te similar Darts ineach of. the views Y' Referring flrstfto Fig. l, the reference character. i dedgnates a non-conducting container i made, for example, of glassand consisting. et two chambers connected together at the lower end by a tube. The upper portion oleaeh chamber con. talus an inert gas E, such, for example, anhydrogen. The lower portion ofeach chamber and the w. tube contain a conducting liquid 2, preferably mercury, with the liquid free to flow between the chambers. When the conducting liquid 2 is at the normal level, as herem shown, a contact 1 is innnersed in the liquid and a contact H isA n above the level of the liquid. A contact 9 is im-y mersed in the liquid at all times regardless d changes m the level of the liquid. This arrangement of contacts is similar to the contacts in the usual type of relay wherein contact 9 is the heel, 35 contact 1 is the back contact and contact Il is the front contact. The chamber at the left of the drawing contains also, a heating element 5, connected to a terminal 3, and a terminal l, which are analogous to the operating winding and tern minals of the usual type of relay.

To operate the relay a source of current is applied to terminals 3 and 4 of heating element 5. The heat generated by the element 5 expands the volume of gas 6. The resulting increase in gas pressure lowers the liquid level in the left-hand chamber below contact 1 and raises the level of the liquid in the right-hand chamber above contact Il. The level of the liquid then remains stationary as long as the current is applied to the 50 heating element. When the current is removed from the heating element, the gas in the lefthand chamber cools and contracts with a resulting decrease in pressure which allows the liquid to return to the normal level.

It is apparent from the foregoing description that circuit can be made or broken in response to me enelgizstiom or deenergization of heating element l by the resulting immersion m non-im- :session o! either contact 'I or contact Il in the conductmgliquid.

Referring now to Fig. 2, the relay here shown contain aconducting liquid 2', and an inert gas U, and s constructed similar to the relay shown in Fig. l, except that the container i is balanced on amici-lm I, and the right-hand chamber is m pridclwh a heating element 5*, connected to a terminal 3 and a terminal 4, similar to the heath. elemcnt and terminals 3 and' 4 in the lett-hand chamber. Thus the container is free to en inclined position in response to the distribution of the liquid and can be tilted from ride to side depending upon which heating element il Mailed. Cuntinmus energization is notreenuredbecaasethecontainerisheldby gravity in the to which it was last oper- 2a ated. Thewntlets, and Hareslmilartothe contacte having the samev reference characters in Pig. i, and coactsl and ii are-immersed or notintheliqmiupontowhichside the container is tilted.

Rotating 'new 'to Hg. 3, the modified portion o! the relay hereahown is similar to the left-hand chamber of the relay shown in Fig. 1, with the additional resistor itin series with the heating elementi, Under-normal conditions, as shown ao hem, therexior it isimmersed in the liquid 2. histamine shuntadendisnoteifectearor limiting the flow of current in the heating ekment 5. 'This arrangement provides a circuit of a relatively low resistance which permits a higher temperature for heating element 5 and therefore a quicker change in the level of the liquid. After the liquid in the left-hand chamber is forced downward to a predetermined level in response to the energization of heating element 5, the re- 40 sistor I3 is free of the liquid and is therefore effective for limiting the flow of current in the heating element 5, thus saving energy during the remaining portion of the energized period.

The resistor I3 is shown in the horizontal po- 45 sition which causes a sudden change in the resistance of the heating element circuit because the entire resistor is free from the shunt imposed by the liquid at the moment the level of the liquid falls below the level of the resistor. If it is desired to produce a gradual change in the resistance of the heating element circuit, the resistor I3 can be placed in a vertical or in an inclined position so that the fall of the level of the mercury uncovers the resistor gradually.

While the resistor I3 shown in Fig. 3 is described as a feature applicable to the relay shown in Fig. 1, it can also be applied to the relay shown in Fig. 2.

Referring now to: Figs. 4 and 5, I have here shown an assembly, in a case I0, of four individual relays, but I will describe only one relay since all are identical in structure and operation. A non-conducting tube Ia, open at each end and containing a conducting liquid 2, is enclosed in a case I 0 which is divided into two chambers by a baiiie plate I2, each chamber containing an inert gas I5. When the conducting liquid 2 is at the normal level, as herein shown, a contact 1a is immersed in the liquid and a contact IIa is above the level of the liquid. A contact 9a is immersed in the liquid at all times regardless of the level of the liquid. The left-hand chamber is provided with a heating element 5b to which is connected a terminal 3b and a terminal 4b. To operate the relay a source of current is applied to the heating element 5b through terminals 3b and 41. The heat generated by the element 5b expands the inert gas 6. The resulting increase in gas pressure lowers the level of the liquid in the left-'aand side of the tube below contact Ia and raises the level of the liquid in the right-hand side of the tube above contact I la, thus providing a means for making or breaking a circuit similar to that described for the relay shown inV Fig. l.

The tubes designated by the reference characters Ib, IG and Id with associated contacts 1, 9 and I I having the same exponents, correspond in all respects to the tube Ia with its associated contacts l, 53a and IIa. Each tube with its associated contacts is insulated from the other tubes and associated contacts in order that the circuits controlled by the relay can be kept separate.

Since the gas chamber and the heating elenient are common to all tubes, it is readily apparent that the pressure on the liquid is uniform and therefore -a number of circuits can be made or broken simultaneously in response to energization or deenergization of the heating elenient.

The relay shown in Fig. 2 can also be used for an assembly similar to that shown in Figs. 4 and 5.

Although the relay shown in Figs. 4 and 5 consists of an assembly of four individual tubes with associated contacts, this relay can consist of any convenient'number of tubes md associated contacts.

It is understood that container I, or tube I, need not necessarily be made of glass, that liquid conductor 2 need not necessarily be mercury and that inert gas 6 need not necessarily be hydrogen, as any materials or substances having similar and suitable characteristics can be used.

From the foregoing description it is apparent that my invention has certain advantages over the usual type of relay. It h-as no moving contacts and requires no magnetic structure or coils. It is universal for either alternating or direct current operation. It can handle heavy loads since circuits are made or broken in the presence of an inert gas. The contacts are of low resistance and are permanent since no contact spring pressure is involved. A number of contacts may be made or broken simultaneously since the gas pressure on the liquid in each tube is equal, and a wide range of time elements can be obtained by varying the current supplied to the heating element or by other means well known to those skilled in the art.

Although I have herein shown and described only a few types of relays embodying my invention, it is understood that various changes and modifications may be made therein Within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. A relay, comprising a non-conducting cha-mber containing a conducting liquid and an inert gas, a contact immersed or not in the liquid when the level of said liquid changes in response to a change in the volume of said gas, a heating element for governing the Volume of said gas, a resistor contained in said chamber and immersed or not in said liquid according to the level of the liquid, and a circuit for said heating element 'including said resistor.

2. A relay, comprising a plurality of non-conducting tubes of equal size each containing an equal amount of a liquid conductor, a non-conducting chamber containing an inert gas and enclosing said tubes, a plurality of iuiiform contacts simultaneously immersed or not in the liquid according to the uniform level of said liquid, and a. heating element for controlling the volume of said gas to govern the uniform level of said liquid.

NORMAN F. AGNEW.

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