US1826570A - Electrical switch - Google Patents

Description

1931- L. A. M. PHELAN ET AL 1,326,570

ELECTRI CAL SWITCH Original Filed Oct. 22, 1927 fed-"Get. a, 1931 PATENT OFFICE LOUIS A. M. PHELAN, OF CHICAGO, ILLINOIS, AND PAUL 8. BEAR, OF ELKHART, INDIANA, ASSIGNOBS, BY MESNE ASSIGNMENTS, TO MINNEAPOLIS-HONEYWELL REGULATOR COMPANY, OF MINNEAPOLIS, MINNESOTA, A CORPORATION OF DELA- WARE ELECTRICAL SWITCH Application filed October 22, 1927, Serial No. 228,043. Renewed September 8, 1931.

Our invention relates to electrical switches of the liquid flow type and refers particularly to mercury contactors that are adapted for commercial operations and to meet requisite service conditions as to current carrying capacities, voltages, life, reliability, etc.

An object of our present invention is to provide an electrical contactor of the character indicated having an hermetically sealed .0 envelope of glass or other insulating fragile material, electrodes sealed in the envelope and a body of mercury therein and being economical to manufacture and efficient in operation.

Another object of our invention is to provide an electrical contactor having an hermetically sealed container of glass or other fragile material which houses electrodes, a body of mercury and a filling of inert gas,

such as hydrogen, the latter being placed within the sealed container after the same has been evacuated of air and other deleterious gases. The container is, of course, hermetically sealed at the points where the-leading- !5 in wires for the electrodes extend therel0 fective but such defects are incapable of bethrough and where the container-is tipped ofl" through which the air is exhausted and the hydrogen gas -or other inert gas is filled into the container. Such seals are sometimes deing discerned by very careful inspection. By our present invention we apply exteriorly of the container, at the points where the seals are made, a flexible cement which ensures the seals against the development of leaks. I

A Another object of our invention is to pro vide a mercury contactor that is completely covered with the aforesaid flexible cement which adheres closely to the exterior walls of the container thereby serving as a protective covering or shock-absorbing medium for the fragile container.

Another object of our invention is to provide a mercury contactor wherein the leading-in wires at the points where they project exteriorly of the envelope and are connected to flexible electrical conductors, the latter serving to connect the contactor to an external electrical circuit. are embedded in a body of cement that holds the flexible conductors in close contact with the envelope thereby preeluding these connections from being broken when the flexible conductors are moved, such as occurs constantly when the electrical contactor is being tilted.

Another object of our invention is to provide an electrical contactor mounted in a suitable holder which permits the flexible conductors extending from the contactor to be threaded through the holder thereby minimizing or substantially eliminating all bendvention, reference may be had to the following description and the accompanying drawings, in which Figure 1 is a top plan view, partially in section, of an electrical contactor embodying one form of our invention;

Fig. 2 is a view, partially in section, and partially in elevation of the contactor illustrated in Fig. 1; 4

Fig. 3 is a top plan view of the device of Figures 1 and 2 showing with particularity a method of embedding the flexible conductors, attached to the leading-in wires, in the flexible cement that serves both to seal the envelope and to protect the connections between the flexible conductors and the leadingin wires from bending movement;

Fig. 4 is a plan view of a modified form of a contactor embodying another form of our invention;

Fig. 5 is an end view of the contactor of Fig. 4;

Fig. 6 is a side view, partially in section, of another form of our invention;

scope and characteristic features of our inthroughjone "en" Fig. 7 is plan view of the device of Fi 6; I

Fig. 8 is a view in elevation of another cm of a contacto embodying our invention; and

Fig. 9 is a view in elevation of another modified'for-m of our invention.

Referring toj the device shown in Figs. 1,

2 and'f3-the contactor comprises an envelope 1 made of*fra' ile material, such as glass,

I of which leading-in wlres 2- and 3 are sealed by employing a pinch seal construction '4j-of the character utilized in sealing the'leading-in wires in an incandescent lamp bulbi" The leading-in wires 2 and 3 are disposedf 'side by side transversely of the tubular container 1. The leading-in wires may be madeof any suitable material that is adapted to'form permanent hermetical seals wlth glass such, for instance, as the well known Dumet wire. Of course, these leading-in wires may be made of other materials, that serve to produce more or less satisfactory seals.' If the fragile container 1 is made of a high melting glass such as pyrex, the leading-in wires may be made of tungsten. The pinch seal 4 permits the leading-in wires 2 and 3 to extend outwardly beyond the container 1, as shown in the drawings. The leading-in wires 2 and 3 project interiorly of the container 1 and are provided at their inner ends with large-headed electrodes 5 and 6. The container 1 is also evacuated of air and other deleterious gases and preferably filled with an inert gas, such as hydrogen. The exhaustion and the refilling of thgcontainer 1 is elfected through a tubulation which is shown as being sealed off at 7 A body of mercury 8 is housed within the container 1 and serves to make and break the elegtrical' circuit between the electrodes 5 an 6.

If the leading-in wires 2 and 3 are made of Dumet or other materialthat is likely to cause deterioration of the contactor in service, the electrodes 5 and 6 are .then connected to their respective leading-in wires through rods 9 and 10 made of a suitable material, such as iron or tungsten and which rods, in turn, are welded or otherwise secured: at points 11 and 12, respectively, to the leadingin wires 2 and 3. The glass constituting the container 1 is brought down to totally embed the Dumet leading-in wires 2 and 3 thereby f precluding their exposure interiorly of the container.

The materials entering the construction of the contactor described may be those set forth in U. S. Patent No. 1,598,874, and the method of attaching the electrodes 5 and 6 to the Dumet leading-in conductors 2 and 3 may be that described in U. S. Patent No. 1,598,875. It is to be understood, of course, that we are 'not to be limited to the specific materials herein described or'thus referred to in the aforesaid patents. The electrodes 5 and 6 may be made of a number of metals, such as .glass known as Q, 02P an iron nickel, platinum, cobalt, tungsten, mo- 1 bdenum as well as alloys, such as nickelromium alloys or cobalt-iron alloys. The same materials may be employed for making the rods 9 and 10 that serve to connect the big-headed electrodes 5 and 6 to the leadingin conductors 2 and 3. The container 1 may be made of glass, orcelain pyrex, quartz or d, therefore, when the term glass is used herein, it is to be understood that it comprehends within its meaning such materials as are enumerated, as well as other materials that are suitable for making the envelope or container of a mercury contactor.

The pinch seal 4 is of a well known type of construction and has been employed in the manufacture of incandescent lamps when the "leading-in wires are sealed into the bulb by a glass sealing machine. Flexible conductors 13 and 14 are connected respectively to the exteriorly projecting portions of the leading-in wires 2 and 3, these flexible conductors preferably constituting a flexible copper conductor having an exterior braided insulating covering. Flexible conductors of this character are well known in the art. The interior conductin elements of the flexible conductors are solfered, welded or otherwise secured, as shown at 15 in Fig. 2, to the leading-in. wires 2 and 3. The flexible conductors 13 and 14 are then bent so that the portions thereof adjacent to the points of connection to the leading-in wires are in close contact with the envelope 1. In this manner, the flexible conductors are extended longitudinally of the envelope 1.

The end of the contactor whereat the pinch seal construction 4 obtains is then completely embedded within a flexible cement 16 which closely adheres to the walls of the container and serves as a duplicate seal for the pinch seal construction 4. The cement 16 also impregnates the insulating covering of the flexlble conductors 13 and 14 and holds these conductors firmly in contact with the walls of the envelopel. In this manner the points of connection between the leading-in wires 2 and 3 and the flexible conductors 13 and 14 are wholly embedded within the cement 16 which precludes these points of connection rom being subjected to any mechanical strains or stresses that are likely to interrupt the electrical circuit comprising the electrodes 5 and 6. N0 bending action can be transmitted to these points of connection and. consequently, these connections are retained substantially permanent. The cement 16, besides serving as an extra seal for the pinch seal construction 4 and as a protection for the connections between the flexible conductors 13 and 14 and the leading-in wires, constitutes a shock-absorbing medium for an blows or shocks that otherwise would brea the fragile or glass envelope 1. If desired,

terials but is preferably a flexible cellulose for the cement; if a yellow color is desired ester cement or heavy pyroxylin cement, such as a solution of celluloid in acetone or alcohol with the addition of a suitable filler. Coloring material may also be added to the cement thereby imparting any desired color to the tip of the envelope, as well as to the pinch seal portion 4. If a green color for the ccment 16 is desired, Paris green or chromium pigment would be suitable coloring agents 7 lead chromate would be a suitable pigment; if a red color is desired, many of the well known red lake pigments may be employed and if a white color is desired, zinc oxide lithopone, or chalk maybe employed. Of course, other porcelain cements that adhere to glass and the like may also be suitable.

Therefore, the term cement as employed herein comprehends within its meaning such materials that are preferably inert and elastic or shock-absorbing when dried, electrically insulating, non-hygroscopic and capable of providing air-tight seals when applied exteriorly of a glass container.

In Figs. 2 and 3 the contactor is shown as being positioned within a clip holder 17, the same being provided at its rear central portion with an opening 18a by means of which the clip holder 17 may be mechanically connected to any suitablefoperating mechanism. The flexible conductors 13 and 14 are threadted through the clip holder 17 as shown in Fig. 3. The axis of the tilting movementof the contactor coincides with the axis of the opening 18 formed in the clip holder and,

therefore, when the flexible conductors l3 and 14 are threaded through the holder 17 the mechanical resistancethat these conductors may offer to the tilting movement of the contactor is substantially minimized. At the same time, this constructionprecludes the conductors 13 and 1 4 from being subjected to bending movements adjacent to the cement covering 16 and the pinch seal 4.

In the specific construction illustrated in Figs. 1 to 5, inclusive, an electrical contactor is shown having atubular glass container wherein the diameter of the envelope 1 is minimized by reason of my present invention. The electrodes Sand 6 of thecontactor of Figs; 1 to 3, inclusive, possess large heads. are of substantial concentrated mass and are disposed at the same end of the container which embodies the pinch type of seal. As hereinbefore stated, the pinch type of seal is highly advantageous for the reason that contactors embodying this form of seal may be machine made. In this form of contactor the while, at the same time, the diameter of the' container 1 is minimized by reason of the staggered positioning of the electrodes 5 and 6 therein. At the same time, a pinch seal may be employed permitting of the contactor to be machine made. The quantity of mercury 8 required in a contactor of this construction is considerably reduced over that which would be required in a contactor wherein big-headed electrodes are placed side-by-side and spaced from each other transversely of the container.

In Figs. 2 and 3, the flexible electrical conductors 13 and 14 are shown as being brought through the body of cement 16 at the top of the envelope 1. In the contactor illustrated in Figs. 5 and 6, the leading-in conductors 13' and 14 are shown embedded in the cement 16 in such manner that they extend longitudinally of the envelope 1 along one of its sides, in this instance, on the side of the container adjacent the rear portion of the clip hoider 17. The positioning of the contactor of Fig. 4 within the clip holder 17 is best illustrated in Fig. 5 wherein the flexible conductors 13' and 14 are shown as being superposed upon each other at the end of the envelope but extending longitudinally thereof on that side of the envelope which permits of the flexible conductors 13 and 14' being threaded through the clip holder 17 as shown.

In'the contactor of Figs. 6 and 7, the pinch sealconstruction is used but the electrodes 18 and 19 are shown asconstituting, extensions to the leading-in wires and as being placed side-by-side and spaced from each other transversely of the container. The electrodes 18 and 19 are not of the big-headed type of construction, such as the electrodes 5 and 6 of the contactor hereinbefore described. If the leading-in wires to'which the electrodes 18 and 19 are attached are made of tungsten or some other metal which does not cause deterioration of the contactor and which supply substantially permanent hermetic seals with the glass container, then no provision need be made for precluding exposure of the leading-in wires intcriorly of the container. However. if the leading-in wires -to which the electrodes 18 and 19 are attached the container. The electrodes 18 and 19 may seal so as to preclude their exposure within be secured to the leading-in wires in any suitable manner, such as by welding or otherwise. The contactor of Figs. 6 and 7 shows the flexible electrical conductors connected to the leading-in wires as being disposed in a-manner similar to the leading-in conductors shown in Figs. 4 and 5. The flexibleconductors connected to the leading-in wires have their'ends adjacent to the points of connection embedded in the body of cement 16. The tip 16' of the container, if desired, may also beembedde'd in a body of cement, such as I have hereinbefore described. In this fashion. the envelope is provided with'a double seal at those points where the glass has been scaled during the manufacture of the contactactor.

The structure shown in Fig. 8 comprises a contactor similar to that illustrated in Figs. 6 and 7 except that it is of diminutive size. .The clip holder in this instance comprises two spaced clip portions 20 and 21 and the rear of the holder is provided with three openings 22, 23 and 24 that'serve as mounting means for the contactor.

I In Fig. 9 we have shown a mercury contactor of simple construction, the envelope of which is completely covered with the cement that we have described in connection with the pinch seal of the contactors shown in the other figures. The seals are thus provided with a protective coating as well as the whole of the fragile envelope. The cement coating serves as a shock-absorbing medium and permits the contactor to be more roughly handled than has heretofore been possible with contactors not provided with this external flexible cement covering that serves as a shock-absorbing medium.

While we have herein described several embodiments of our invention, it is to be understood that many modifications may be made therein without departing from the spirit andscope of the appended claims.

lVe claim:

1. An electric switch comprising an envelope of fragile insulating material, leadingin wires sealed therethrough and terminating at their inner ends in electrodes, a body of mercury in said envelope, and a coating of resilient cement applied exteriorly of said envelope to protect it from mechanical .shocks. i v

2. An electric switch comprising an envelope of fragile insulating material, leadingin wires sealed therethrough and terminating at their inner ends in electrodes, a body of mercury in said envelope, and a substantially impervious and inert coating of resilient and electrical insulating cement adher- 7 ing to said envelope exteriorly thereof.

' 3. An electric switch comprising 'an enve- ,lope of fragile insulating material, leading in wires sealed therethrough and terminatdisposed adjacent to each other at one end of said envelope, a body of mercury in said envelope, an inert gas filling for said envelope, and a substantially air-tight protective coating of resilient'and inert cement applied exteriorly of said envelope and super-sealing said envelope whereat it has been hermetically sealed through the application of heat said resilient cement serving to protect said envelope from mechanical shocks.

4. An electric switch comprising a container of fragile insulating material, leadingin wires sealed therethrough and terminating attheir inner ends in electrodes, a body of mercury in said container, and an airtight coating of electrical insulating and re silient cement enveloping completely said container, said coating serving as a cushion for the walls of said container.

5. An electric switch comprisin an envelope of fragile insulating materia leadin in wires sealed therethrough at one end of said envelope and terminating at theirinner ends in electrodes that are positioned adjacent to where said leading-in wires are sealed through said envelope, a body of mercuryin said envelope, and an air-tight protective coating of resilient and insulating cement applied exteriorly of said envelope adj acent to those points whereat said leading-in wires are sealed therein to protect said envelope from mechanical shocks.

6. An electric switch comprising an envelope of fragile insulating material, leading-in wires sealed therethrough at one end of said envelope and terminating at their inner ends in electrodes that are positioned at one end of said envelope, a body of mercury in said envelope, flexible conductors connected to said leading-in wires, and a resilient protective coatiilg of cement applied exteriorly upon said envelope adjacent to the points wherea't the said leading-in wires are sealed therein, said cement embedding the points of connection of said flexible conduc- 1 tors to said leading-in wires and serving to protect" said envelope from mechanical shocks.

7.-' An electric switch comprising an elongated envelop of fragile insulating material, leading-in wires sealed there-through at one end of said envelope and terminating at their inner ends in electrodes that are positioned at is connection to said leading-in wires are held firmly in close contact with the wall of said envelope, said resilient cement serving to protect said envelope from mechanical shocks.

8. An electric switch comprising an elongated envelop of fragile insulating mateenvelope from mechanical shocks.

9. An electric switch comprising an envelope of lass having leading-in wires sealed therein a jacent to one end of said envelope and'terminating at their inner ends in electrodes, a body of mercury in said envelope, the latter being tipped off, and a coating of resilient air-tight cement applied exteriorl of said envelope. and embedding the tippe ofl' portion thereof and the seals through which the leading-in wires are admitted within said envelope.

10. An electric switch comprising a tubular elongated container, leading-in wires sealed in said container through the medium of a pinch seal and spaced from each other transversely of said tubular container, large headed electrodes interiorly of said container connected to said leading-in wires and spaced from each other longitudinally of the container, and a body of mercury in said container'.

11. An electric switch comprising an elongated glass container, spaced leading-in wires sealed at one end of said container through the medium of a pinch seal, said leading-in wires being spaced from each other transversely of the container, electrodes disposed within said container and connected to said leading-in wires, said electrodes constituting enlarged heads that are spaced from each other along the longitudinal axis of said container, a body of mercury housed in said container, flexible conductors connected to .said leading-in wires exteriorly of said container, and a body of insulating cement embedding the exterior portionsof said lead-- ing-in wires and holding sa' flexible conductors in close contact wit the exterior surface of said container.

12. An electric switch comprising an elongated glass container, spaced leading-in wires sealed at one end thereof through the medium of a pinch seal whereb said leadingin wires are spaced from eac other transversely of the container, electrodes disposed within said container and connected to said leading-in wires, said electrodes constitutm enlarged heads that are spaced from each ot er along the longitudinal axis of said contalner, a ody of mercury housed in said container, flexible conductors connected to said leading-in wires exteriorly of said container, a body of electrical insulating and hermetically sealing cement embedding the exterior portions of said leading-in wires and holding said flexible conductors in close contact with the exterior surface of said container, and a filling of hydrogen gas within said container.

13. An electric switch comprising an elongated glass container of insulating material, leading-in wires sealed at one end thereof through the medium of a pinch seal, enlarged electrodes within said container and disposed at one end thereof, said electrodes being spaced from each other along the longitudinal axis of said container which is tippedofi' at its end opposite to said pinch seal, a body of mercury in said container, flexible conductors connected to said leading-in wires exteriorly of said container, an insulating cement embedding the pinch seal and the polnts of connection between said flexible conductors and said leadin -in Wires, and a second body of cement embe ding the tippedoff portion of said container.

14. An electric switch comprising an elongated tubular container of fragile insulating material, leading-in wires sealed at one end thereof through the medium of a pinch seal, enlarged headed electrodes on the inner ends of sald leading-in wires and positioned in the end of the container adjacent the pinch seal, flexible conductors connected to the exterior portions of said leading-in wires, a 105 body of mercury in said container and a body of insulating and resilient cement embeddlng the pinch seal and the points of connection between said leading-in Wires and said flexible conductors whereby said flexible conductors are held adjacent to the pinch seal, said cement protecting said envelope from mechanical shocks.

15. The combination with a holder, of an electric switch disposed therein and held by 115 said holder about its central portion, said electric switch comprising a tubular container, leading-in wires sealed at one end thereof, electrodes disposed in said container and connected to said leading-in wires, a body of mercury in said container, flexible conductors connected to said leading-in wires exteriorly of said container, and a body of insulating and insulating cement embedding the exterior portions of said leading-in wires at the points v 6 maam' nally of said container and through said holder.

16. An electric switch comprising a tubular elongated container, leading-1n wires 5 sealed in said containerthrough one end thereof and spaced from each other transversely of said container, enlarged headed electrodes in said container that are connected to said leading-in wires and spaced from each othera, relatively short distance longitudinally of the container, and disposed at one end of said container, and a body of mercury in said container.

17. An electricswitch comprising a tubular elongated container, leading-in wires sealed therein and spaced from each other transversely of said container, enlarged headed electrodes housed in said container and at one end thereof that are severally connected to said leading-in wires and spaced a relatively short distance from eachother longitudinal- 131 of the container,'and a body of mercury in said container. e

. 18. An electric switch comprising an hermetically sealed container of fragile insulating material, a leading-in wire sealed therethrough and terminatmg at its inner end in an electrode, a body of mercury in said container and an air-tight coating of cement applid exteriorly to said container and covering at least that portion thereof whereat said leading-in wire is sealed through said container, said cement providing an additional hermetic seal around said leading-in wire seal and protecting said container thereat from mechanical shocks.

In witness whereof, we have hereunto subscribed our names. 40 p LOUIS A. M. PHELAN.

7 PAUL S. BEAR.

Images