US1598876A - Electrical apparatus - Google Patents

Description

| A. M. PHELAN EI AL Sept. 7 1926.

ELECTRICAL APPARATUS Filed Dec. 22', 1922 lii Patented Sept. 7 1926.

UNITED STATES PATENT; oFFm LOUIS A. 1!. runner AND ram; 1:.

CBAMBLE'I, OI BELOIT, WISCONSIN.

nnacrnrdar. Arrmrus.

Application filed December 22, 1922; Serial No. 608,504.

' Our invention relates to electrical appa-- ratus and it has special reference to improvements in electrical contact-making devices comprising spaced electrodes that are sealed into a closed container and are adapted to be brought into electrical conducting relation with one another through the agency of a movable conducting body, preferably a fluid such as mercury, likewise disposed in said" container and which, on being tilted, is instrumental in performing the circuit-closing and circuit-opening functions of the device. Our invention may comprise a flat elon-' gatedcontainer preferably in the form of a glass tube that serves to enclose a pair of co-operatin'g electrodes and a body of conducting liquid, such as mercury, the latter being adapted to bridge the electrodes within the tube. The tube is preferably disposed when installed to occupy normally a position neighboring on the horizontal and is intended to besuitably supported so that it may be tilted at the expense of'very little energy in order to bring the conducting liquid into and out of bridging relation with. the electrodes.

within the tube and as shown in this particular instance, the ends of the electrodes which The electrodes are sealed are bridged by the body of conducting fluid are located adjacent one end of the tube.

A. particular object of our present form of construction is to provide a container tube of such shape that it will serve to guide the conducting fluid in a definite channel. Such a construction. is for the pur ose of'avoiding accidental contacting o the mercury with the electrodes due to splashing or other undesired movements of thebody. of mercury.

Another object of our invention is'to provide an efiicient and very simple form of electrode structure. 7

A 'furtherobject of our invention is to provide .a contactor device ofthe type indicated that will be economical to construct and which will possess a long'life even when subjected to serious mechanical abuse.

erence to the following description. and ac of the tube 1 and serve to bring the current through the glass walls of this companying drawings, in which' lgure 1 1s a vertical sectional vlew of one modification of device embodying our invention;

Fig. 2 is an end view of the dev ce shown Fig. 3 is aplan view of device;

F 4 is an enlarged detail view, partly in section showing the construction of the electrodes;

Figs. 5, 6, 7 and 8 are detailed cross-sectional views showing various possible modifications in the shape of the container.

'The above described views, with the except1on of F 4, for clearness illustrate the invention in approximatelytwice its natural size; It may be here noted that the size of the container is an important consideration in its design because of the and surface tension properties of the body of mercury.

.The device as shown comprises -in a general Way acontainer 1 preferably formed of glass or a like material, electrodes 2 and 3 sealed and supported in the interior of the container tube 1 and a body of conducting fluid, such as mercury 4, which is free to peculiar capillary flow along the bottom of the interior of the the various parts and to select the proper materials. It is preferable that the mercury 4be substantially free from impurities of all kinds. The electrodes 2 and 3 are preferably constructed of a pure metal, such as iron, which is not chemically affected by the mercury in the presence of the extreme temperatures of electrical arcs which may occur at the electrodes. The interior of the tube 1'" is preferably evacuated and filled witha gas which does not combine in any way with the metal of the electrodes 2 and 3, or with the mercury in the presence of the intense heat. Hydrogen at substantially atmospheric pressure has been found to be satisfactory for this purpose. The tube .1 is evacuated and filled with the inert gas and sealed off at a tip 5. i

The electrodes 2 and 3 may be\formed at the ends of thin. cylindrical sleeves 6 and 7,

respectively, formed of a metal such as pure iron. The sleeves 6 and *7 are supported upon and serve to encase the inwardly extending ends of leading-in wires 8 and 9, respectively, which pass through the walls tube without the possibility of any leakage of gas .in or out 'of the tube at this point. Dumet wire 'ispreferably usedfor no I these leading in wires because of its desir-- able expansive.=properties when sealed in V glass. The sleeves 6 and 7 are extended for a slight distance along the leading-in wires 8 and 9, respectively, into the glass structure and thus serve to protect completely the Dumet Wire from exposure to the intense heat and gases within the tube 1.

Glass shanks 10 and 11 are formed on the walls of the tube 1 at a point where the wires 8 and 9, respectively, are sealed. These shanks serve to support securely the electrodes 2 and 3 and provide for an extended sealing area between the wires 8 and 9 and the glass of the tube 1. It will be further noted that the glass shanks 10 and 11 are located at the ends of and at the upper side of the tube 1 so that they are remote from the body of mercury 4 and from any arcing that may occur at electrodes 2 and 3. Thus the possibility of injury by heat to the sealed portions of the wires '8 and 9 is avoided.

The sleeves 6 and 7 are flattened at their ends in order to form electrodes 2 and 3 and also in order to close their ends against access of the mercury or gas within the tube 1. It will be noted that as shown, the electrode 3 is flattened in a direction parallel to the axis of the tube 1 and consequently parallel to the direction of the flow of the body of mercury 4. The electrode'3' is also placed in an inclined position in respect to the body of mercury 4:. The advantage of this particular form of flattened inclined electrode is to enable the electrode to offer as little resistance as possible to the movement of the body of mercury 4 and to still retain a large contact area with the mercury. The resistance to the movement of the mercury into and out of circuit-making;

position is a very important consideration in the construction of contactors of this character, which are-designed to operate when tilted to only a 'very slight angle. In

such cases the .flow of mercury can be very easily checked or entirely prevented.

By reference to Figs. 2 and 5, it will be noted that the tube is shown with-a pronounced flattened cross section. With this design of the cross section of thetube, it will be noted that sides 12 and l3,extend up vertically for a considerable distance in contact with the sides of the body of mercury 4 and thus serve to form a channel which guides the mercury and serves to prevent any splashing or undesirable movements of the liquid. When the mercury flows in the channel of this type, its. depth and stability can be much more easily con trolled than when the'm'ercury is placed in the usual tube of circular cross section, such for example as indicated in Fig. ,8. With the shape of tube shown in Fig. 2, practically all movement of the mercury is limited to that in a direction parallel to the axis of the tube, which is the .only' direction of movementwhich is essential for the proper action of the contactor.

In certain instances it is desirable to use a contactor of this type which will actuate upon being tilted only a small number of degrees from the horizontal. In such cases, it is desirable to eliminate as much of the frictional effect as possible between the moving body of .mercury and the container walls. It has been found that expedients such as shown in Fig. 5 for stabilizing the mercury also have a slight tendency to retard the free 'fiowing of the mercury even along its intended path. Accordingly it has been found to be advisable to modify the cross-sectional shape of the container in order to secure the most desirable results under different tilting angles and stabilization requirements. In other words, it is desirable to stabilize the mercury as much as possible without rendering its action too sluggish.

It has been found that mercury flows very freely upon a horizontal fiat surface. The design shown in Fig. 6 makes use of this fact since the lower side of the tube is formed as a fiat surface upon which the mercury flows or rolls withconsiderably more freedom than on the rounded surface shown in Fig. 5. The vertical parallel side walls for stabilizing the mercury are retained in Fig. 6 as in Figs. 2 and 5. Figs. 7 and 8 show forms of cross-sections which respectively tend to permit still greater freedom' and less stabilization of the mercury than do the above described structures.

As shown in Fig. 2, it is preferable to space the fiat side walls of the container at an appreciable distance apart in order to prevent unnecessary sluggishness of the mercury as when too closely confined. It will be further noted that considerable space at the upper side of the container is shown into which the mercury does not extend. This ample amount of space permits the placing of the electrode leads and supporting shanks in a position where they will not interfere with the free flowing of the mercury when in its proper channel. Furthermore, the top wall as shown is at a sufficient distance from the bottom wall to prevent the cooperation of these walls with the other walls of the container in holding or restraining the body of mercury, in caseinterpreted and limited only art and by the scope of the appended claims. r c

What we claim as new and 'desire to secure by Letters Patent of the U. S. is 1. An electrode for contacting with a movable body of conducting liquid, com-- a tubular shell flattened at its end rection parallel'to the movement of prisilzigJ said body of conducting liquid. q 2. In an electrical device, the combination of a supporting wire, and a tubular protecting shell surrounding said wire, an

end of said shell extending beyond said wire container, a movable body and being crushed to close said shell and to form an electrode.

3. An electrical device comprising a con tainer, a movable body of conducting liquid in said container, and electrodes in said container in the ath of said movable body of liquid, said e ectrodes being formed of tubular shells, the ends of which are-crushed to close said shells.

4. An electrical contactor comprising a of conducting liquid in said container, and electrodes in said container in the path of said movable body of liquid, one of said electrodes being ment of said body of liquid.

formed of a tubular shell flattened in a direction parallel to the direction of move- 5. An electricalcontactor comprising a container, a movable body of conducting liquid in said container, and electrodes in said container in the path of said movable bodyof liquid, one of said electrodes being flattened in a direction parallel to the direction of movement of said body of liquid.

6. An electrical contactor comprising a container, a movable body of conducting liquid in. said container, and electrodes in said container in the path of said movable body of liquid, one of said electrodes being flattened in a direction parallel to the direction of movement of said body of liquid and Lpositioned in an inclined relation with re-- spect to the surfaceof said bodyof liquid. 7. An electrical contactor comprising a container, a movable body of conducting liquid in said container, and electrodes in said container in the ath of said movable body of liquid, one of said electrodes having much the larger portion of its surface contact area extending in directions sub stantially parallel to the direction of move ment of said body of liquid.

In witness whereof, we have hereunto subscribed our names.

' LOUIS A. M. PHELAN. PAUL K. CRAMBLET.

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