US2575318A - Mercury switch - Google Patents

Description

MERCURY SW Filed Ja n 8 8 Patented Nov. 13, 1951' MERCURY SWITGH.

Raymond P. Matter-n, Minneapolis; Minn, as-

signor to Minneapolis--idnneyvizellv Regulator Company, Minneapolis, Minn.,.a-cornoration of Delaware Application January 8, 1948, SerialNb. 1,126

(i-Claims. 1.

My invention relates toan electric switch of the type having a liquid contact-circuit closer for controllingthe flow ofcurrent' therethrough, and more particularly to the mounting structurefor the circuit'cl'oser;

It is therefore an. object of this invention to provide an improved construction and arrangement in a switch of this type.

Other objects and advantages will becomeapparent with the reading of the following specification anddrawings wherein:

Figure 1 isa plan view ofthe-preferred-embod iment oi this'invention;

Figure. 2 is a side elevation view of theswitch shown in Figure 1; and

Figure 3' is a cross-sectional viewof the liquid contact circuit closer included in the preferred embodiment of'the-switch.

Figure-4 is a sectional view or the switch taken along linesi' i=of Figure-l.

As is seenin the drawings, my invention is shown. applied to a switch incorporating a rotatable liquid contact circuit controller which is commonly known as: a rotary metal mercury switch. Such a switch can: be seen in my Patent Numbers 2 2693745, dated October: 283 1941 and $342,354, dated Febr.uary:22, 1944; which are as.- signed' to; thesame: assignee as the present inveiie tion. The electricswitch. it generally disclosed in Figures-l and 210i the drawing comprises aliq uid contact. circuit. controller i icpositioned1in= an insulated switch housing: i2. and: mounted; ferrotationv therein-,. to: provide a. manually: operated wall switch-.ofrtl'ietoggletype,

The. liquid contact circuit controller, l;l,.0r rotary' metal mercury switch,v is composed: of: me.- tallic cup-like"; electrodes 1.3;. 1.4-. telescopically in.- terfitted; and. separated. by;- ceramic partition. or bafile. i5. which. has. an; aperture. Iii therethrough to permit contact of. the mercury bodies; [1 separated by thebafiieandcomplete-thecircuittheree through. Aninsulating asbestos washer Zilfurther separates electrodes I 3, l4 and aeglassseal or fill it between the electrode members, seals the.v insulating washer. 2.0 andthe, ceramic in po..- sition. while adhering to. the. electrode. members to provide an airtight seal for. the container. Metal mercury switch H contains a hydrogen atmosphere. with the mercury fill" II, as is conventional in mercuryswitches. Indent 22in'el'ectrode 13 of the circuit closer H isprovided in the manufacture of the switch for the purpose of evacuatingand sealing the sameand is utili'zed herein, as will-' be hereafter described; as a-meansof mounting the switch;

The switch housing i2 is a box like casing structure with a switch receiving recess 28 open at thefi'ont. Thehousing 12 is made of an insulating material, such as molded plastic, and is generally rectangular with the exception of two extendingboss portions 23; 25" wherein the conductivemembers 25 2B are mounted to-the switch housing I i. Switch housing it includes on its inner surface an inwardly projecting boss portion. 217- which is shaped on its inner surface to conform with the surface of electrode E4 of switch: Hi The boss 2*?" providesa fiat bearing surface engaging the fiat end of" switch electrode I74 and acylindrical bearing surface engagmg? a cylindrical surf-ace of electrode I4. These surfaceslbcate the switch H in the housing [2. A. conductor 25: attached to boss portion 23 of switch casing such as byscrew 36', is made of? a good electrical. conductive material and is bent to project into the recess 28- of switch housing: I12 with its free extremity curved to conform with and engage the cup-like electrode I4 of switch III; The conductor 25- isflexible and is: shaped to=engage the electrode It and bias the switch IJIL into. engagement with the. cylindrical bearing: surface: of boss 21: which is curved to conform with electrode M of liquid contact circuit closer ll. Since the entire portion. of the cup -lihe electrodes; l3, M are made of the good electrical conductive material, electrical contact is made-by engagement of conductor ttwith electrode It; A conductor 25, attached at one extremity to: boss: portion 24* of switch housing I2 ina suitable. manner, such as by screw 33, extends into the recess 28 of switch housing [2 and is bent to engage electrode 83- of circuit closer H. Theconductor 26.. is provided intermediate itsendswith. aprojecting knob portion 32 curved to, conform. to. and adapted. to. coact with the indent. 2.2. in. electrode i. switch ii. The free extremity 33 of the conductor 25 engages a surface. of. the. wall. of switch housing !2 insuring definite positioning of circuit closer J l within switch housing [2. Electrical contact is made through engagement of. knob portion 32 and in.- dent' 22' in. a ball and socket connectionwhich further provides. for pivoting of circuit. closer ii about. its axis and centering of. the same, such that it is biased into engagement with the opposite wall of switch housing 32' and is held there for rotation by projecting boss portion 21 and conductor 25 about its axis. The function of conductor 2-6 is tobias the switch H in a direction normal to the operation or bias of conductor 25- providing for a simple yet positive positioning 3 of the switch with good electrical contact therethrough.

Cemented to circuit closer H is handle portion 34 which provides the means of rotating circuit closer I I about its axis. A mounting strap or bracket 35 is provided to mount switch It! in the usual wall box. It is attached to switch housing 2 at lug portions 36 thereon and is provided with opening 31 through which handle 34 extends. Bracket 35 also contains mounting holes 40 therein to facilitate mounting.

Switch I is operated by movement of handle 34 from an off to an on position to establish an electrical circuit through the conductor members and the switch I I mounted therebetween. The switch is centered for rotation about its axis by conductors 25, 2B and boss portion 21. At the same time a good electrical contact is established with the electrodes of the switch which is not affected by rotation thereof. The outwardly extending boss portions 23, 24 of switch housing 12 are fabricated so that external wires, or connections, not shown, can easily be connected to the conductors at mounting screws 3B, 3!. As is shown in Figure 2, movement of handle 34 rotates circuit closer II in such a manner that aperture H5 in ceramic bafile i5 is moved above or below the level of mercury in circuit closer H. In this manner contact is either made or broken between the two pools of mercury positioned on either side of baifie 15.

The mounting structure described above provides a simple and effective way of positively engaging a rotary type metal mercury switch to prevent lost motion and to provide good electrical contact through the switch. This type of structure eliminates the necessity of biasing the switch and handle to predetermined operating positions since frictional engagement of the electrodes of the switch with the conductors and the engaging portions of the switch housing maintain the switch in the position desired.

In considering this invention it should be kept in mind that the present disclosure is intended to be illustrative only and the scope of the invention is to be determined only by the appended claims.

I claim:

1. A switch comprising, a casing member having a switch receiving recess and a boss portion integral therewith projecting into said recess, a rotatably operable mercury switch having two electrodes one of which electrode has a detent, a flexible connector member attached at one extremity to said casing member and having a curved portion conforming to one electrode of said switch making electrical contact therewith, said connector member biasing said switch into engagement with said boss portion, a second flexible electrode secured at one extremity to said casing member and having a projecting knob near its opposite extremity adapted to coact with said detent in said switch electrode making electrical contact therewith, said second named connector member biasing said switch in the direction of said boss and said first named connector member in a plane normal to the operation of said first named connector, said boss and said connector members cooperating to establish a stationary axis of rotation for said switch prohibiting axial movement of said switch while permitting rotational movement about said axis, and means operatively connected to said switch for rotating the same about said stationary axis.

2. A device of the class described, in combination, a switch, a casing member having a recess adapted to receive said switch, a boss integral with said casing member extending into said recess with its inwardly extending extremity adapted to conform to said switch, a flexible member attached at one extremity to said casing and shaped to conform to and frictionally engage said switch biasing it in a direction of engagement with said boss, and a second flexible member attached at one extremity to said casing member and adapted to engage said switch biasing it in a directionnormal to the direction of operation of said first named flexible member, said boss and said flexible members cooperating to establisha stationary axis of rotation for said switch while prohibiting axial movement thereof but permitting rotation of said switch about said stationary axis.

3. In a device of the class described, the combination of a switch casing member having a switch receiving recess, a switch, a boss portion on said casing member adapted to engage said switch, a flexible member secured to said casing and adapted to engage and bias said switch into engagement with said boss portion of said casing member, and a second flexible member secured to said casing and adapted to engage said switch biasing the same in a direction normal to the operation of said first named flexible member, said switch being adapted to be irictionally engaged by said flexible members and slidably rotated about a stationary axis determined by said flexible members and said boss while being held against axial movement.

4. In a, device of the class described, the combination of a casing member having a switch receiving recess, a switch having conductors thereon, a boss portion included in said casing member and adapted to engage said switch, a flexible member secured to said casing and adapted to engage and bias said switch into engagement with said boss portion of said casing member, and a second flexible member secured to said casing and adapted to engage said switch biasing the same in a direction normal to the operation of said first named flexible member, said first and second flexible members being made of electrically conductive material and providing electrical connections to said switch conductors, said boss portion and said flexible members cooperating to establish a stationary axis of rotation for said switch permitting rotation thereon while prohibiting axial movement of said switch.

5. In a switch of the class described, the combination of an insulated casing membe having a switch receiving recess and a switch with a plurality of electrodes positioned therein, a boss portion integral with said casing member extending into said recess and adapted to be engaged by said switch, a flexible connector member of electrical conductive material secured at one extremity to said casin member and frictionally contacting an electrode of said switch biasing said switch into engagement with said boss portion, a second flexible connector member of electrical conductive material secured at one extremity to said casing member and adapted to frictionally engage another electrode of said switch biasing said switch in a direction normal to the operation of said first named connector member, said boss portion and aid flexible connector members defining with said switch a stationary axis of rotation about which said switch is adapted tobe 5 rotated while being mounted to prohibit axial movement thereof.

6. In a device of the class described, in combination, a casing member having a switch receiving recess therein with an aperture leading thereto, a boss portion integral with said casing member having a semicircular surface thereon projecting into said recess, a rotatably operative mercury switch having two cylindrically shaped electrodes one electrode of which has a detent therein, said switch being positioned within said recess of said casing member with one of the electrodes abutting said semicircular surface of said boss portion, a flexible connector member attached at one extremity to said casing member and having a curved portion conforming to and engaging said one of said electrodes of said switch remote from and diametrically opposite said boss and making electrical contact therewith, said connector member biasing said switch into engagement with said boss, a second flexible electrode member secured at one extremity to said casing member and having a projecting knob near its opposite extremity adapted to engage the detent in the other of said electrodes making electrical contact therewith, said second connector member biasing said switch in the direction of said boss and said first named connector member in a plane normal to the operation of said first named connector member, said boss and said connector members cooperating to establish a stationary axis of rotation for said switch prohibiting axial movement thereof while permitting rotational movement of said switch about said stationary axis, and handle means of insulating material attached to said switch extending out of said recess in said switch casing through said aperture.

RAYMOND P. MATTERN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,047,931 Brown July 14, 1936 2,101,093 Payne Dec. 7, 1937 2,142,107 Brown Jan. 3, 1939 2,142,154 Sambleson Jan. 3, 1939 2,275,853 Hutt Mar. 10, 1942 2,365,444 Babenco Dec. 19, 1944 FOREIGN PATENTS Number Country Date 466,257 Great Britain May 25, 1937 520,357

Germany Mar. 10, 1931

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