US2573920A - Coupling actuated magnetic switch - Google Patents

Description

Nov. 6, 1951 w. MCLEOD 2,573,920

COUPLING ACTUATED MAGNETIC SWITCH Filed April 25, 1949 2 SHEETSP-SHEET 1 If)!!! If INVENTOR.

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Patented Nov. 6, 1951 UNITED STATES PATENT OFFICE 2,573,920 COUPLING ACTUATED MAGNETIC SWITCH William McLeod, Chicago, 111. Application April 25, 1949, Serial No. 89,386

This invention relates to improvements in electrical connectors, switches, fixtures, and like devices or units. Generally speaking the invention herein disclosed has to do with such devices as sockets and plugs intended for use as outlets for so-called base-boards and like installations, and for other similar installations wherein an extension circuit is to be established; but it will also appear that my present improvements are also well adapted for use in many other locations, and for many other purposes. For example these improvements are well adapted for use in connection with lamp sockets and bases intended for introduction into such sockets; and for use in switches and like circuit controlling units. Some of these applications of the present invention will be illustrated and described hereinafter.

One object of the invention is to provide a socket element and plug for use in connection therewith, both of such form that when the plug is not in place in the socket the electrical terminals of such socket will be dead or nonelectrified, and such that when the plug is set into place in or in connection with such socket the terminals of the socket will immediately become electrified so as to establish and complete the electrical circuit between the socket and the plug. By this means the terminals of the socket will be at all times electrically dead when such terminals are exposed due to the absence of the complementary plug. Thus danger of improper connection to such socket terminals will be completely avoided, and resulting short-circuiting will be prevented. In like manner, danger of shocks occasioned by contact with the exposed socket terminals will be prevented. Many other advantages resulting from this arrangement will manifest themselves from a study of the present disclosures.

It is a further object of the invention to enclose the connections to the socket terminals within a sealed container or compartment having only sealed and non-moving connections to the outside of such compartment, so that perfoot sealing of the compartment may be elffected, and so that the perfectl sealed condition of this compartment will be maintained for an indefinitely long interval and after a great number of attaching and detaching operations of the complementary plug with the socket. By this means, also, said connections within said compartment may be perfectly sealed against entrance of water, dirt, and other foreign matter, thus ensuring perfect and, con- 2 Claims. (Cl. 200-51.09)

tinuous protection of said connections from the eflects of such water, dirt, and other foreign matter.

In addition to the use of my present improvements in connection with sockets and plugs therefor, there are many other applications wherein said improvements are or will be of great value. One specific application of said improvements relates to their use in connection with lamps and the sockets therefor.

When the features of my present invention are embodied in switching units, as such, the actual circuit closing and opening operations may be produced completely within the housing or enclosure, or through elements which reach to the outside thereof. Both of these forms are illustrated in the drawings to be presently described.

Other objects and uses of the invention will appear from a detailed description of the same, which consists in the features of construction and combinations of parts hereinafter described and claimed.

In the drawings:

Figure 1 shows a longitudinal section through a typical form of socket unit and complementary plug member, embodying the features of my present invention, the plug member being separated from the socket unit a distance suflicient to non-influence the magnetically responsive elements of the socket unit, and to thus bring the exposed contacts of the socket unit into dead condition, and the plug contacts being disengaged from the exposed contacts of the socket unit;

Figure 2 shows a section similar to that of Figure 1, but with the plug member engaged with the socket unit to thus electrify the exposed contacts of the socket unit, and to bring the contacts of the plug member into engagement with the exposed contacts of the socket unit;

Figure 3 shows an end view of the plug member of Figures 1 and 2;

Figure 4 shows a cross-section taken on the lien 4-4 of Figures 1 and 3;

Figure 5 shows a face view of the socket unit plate, with the housing removed therefrom to show the form of the magnetically responsive elements, and the spring elements for normally moving the movable contacts of the socket unit into open circuit position to thus de-electrify the exposed contacts of the socket unit;

Figure 6 shows a modified form of plug member in which the plug member is intended to make engagement with the socket unit by a rotary connection with a socket unit of the type shown in Figure 7;

Figure 9 shows a longitudinal sectionthrough another form of socket and plug combinationin which the engagement of the plug withthe socket i is by a sliding action, this figure being a section taken on the lines 9-9 of Figures 10 and ll looking in the directions pf the arrows;

Figure 10 shows an end view of the plug mem- -ber of thearrangement of Figure 9;

.Figure :11 shows a face-view of the socket unit of the arrangement of Figure 9; #Figure 12 showsa longitudinal section through still another form of socketand plug combination' in which engagement of the plug with the socket is by a rocking movement, the plug member 'being shown in disengaged or open circuit condition; both the arrangements of Figures 9, l0 and I1, and of Figure vl2, being in effect switch constructions; and

Figure 13 shows another form of embodiment :of -my-invention into a switch construction in which the movable or permanent magnet ele- *ment carries no-portion of the current being controlled, all circuits and contacts'being fully en'- closed in the housing-oi the socket unit.

Referring first to the embodiment of the inven tio'n shown in -Figures '1 to 5, inclusive, I have therein shown my'invention as embodied in a con- '=str'uction including the socket unit and the plug member -designated in their entireties by the numerals and 2 1, respectively. The socket unit is shown as including the insulating plate 22 to' the back side of which there are secured i'the-spring'leaf conductors zii amaze, respectively, by the rivets or screws 25 and :26. The free or movable ends '21 and 28 of these'leaf spring conductors come into substantial alignment as well shown in Figure 5. These free or movable ends carry the armatures or keepers 29 and 3B of :soft :magne'tic iron or magnetizable material which will respond readilyto induced flux from another source. Thesecured ends 3! and 32 of these spring leaf elements readily provide terminal connectors @to whichthe-opposite-poles of the source of current are connectedfin well understood manner. Set screws 33 and 34 are shown for effecting suchconnections.

The insulating plate :22 compri es one wall of a housing for the parts just described; and'a suitable enclosure is provided in connection for this wall. In the arrangement shown in Figures :1 .to15, inclusive :this zplate 22 is provided with the integral backwardly extending flange 35 and a :removable cover plate .BE'is secured in water :tight fashion to the edge :of this flange to comsplete "the housing enclosure. Itwill be noted "that-terminal connections may be made to the connectors Stand :32 without having to open the enclosure pr housing. I

In the plate .22 there are securely carriedthe zfourcrivet-ilike plugs or studs 31, 3,8, as and ie.

These are preferably made of magnetic iron of rsoitrcharacter, so that thesestudsmay :bereadily these studs. On the contrary, in Figure 2 the armatures have been drawn towards and into contact with these studs 31, 38, 39 and ti said "studs having been magnetized by flux induced in them. Thus said studs are normally nonelectrified or dead, since they are normally not contacted by the armatures Z9 and 39, which armatures comprise electrical connecting means attached to the spring leaves 23 and 2%, respectively.

The plug member 2! includes the two permanent magnet elements All and 4-2. These are shown as beingof horse-shoe form. and the legs of these two horse-shoes align with the studs 31, 38, 39 and 48 when the plug'member is brought into circuit connecting condition, as shown in Figure 2. These permanent magnets may be of any suitable materiaLsuch as Alnico 5 or other permanently magnetizable material of high retentive character. These two permanent magnets are carried within sockets 4'3 and M of an insulatingplug element 55 and conveniently these horse-shoe magnets :are retained within such sockets'3 and d l by meansof the cross bars '45 and 46 comprising ajportion of such element 555*, which is made of insulating'material such as a synthetic moulded product. Examination of Figures 1 and 2 shows that these horse-shoe magnets are rather loosely set into their respective sockets 43 and 94-, so that said'magnets' may move slightly back and forth,'and side to side, and with slight rocking movements while being still retainedwithin the sockets by the cross bars 45 and 46. These horseeshoe magnets are connected by the short and flexible pig-tail connectors 4'1 and 48 with the terminal'screws 49 and Elkto which the double wire extension cord 5! is-connected'in well understood-manner. The plug element 45 is readily formed of synthetic insulating material by a moulding process or other means; and a removable cover plate 52 is secured on to this element'in convenient manner as by means of thescrew 53.

As already stated the legs of the two horseshoe'nriagnets'are spaced to align with the studs 38, 39 and d9 of the socket unit when the plug member is to be brought into connection with said socket unit. This fact is well shown in Figures 1 and 2. Astheplug member is moved close to the socket unitwith the magnet legs aligned as just explained, there will be flux induced throughmagnetic circuits including the studs 37, 38,39 and $9, and through the armatures 28 and so, thus drawing these armatures towards and into contact with the studs, the armature 28 engaging the studs 31' and 38, and the armature 3F! engaging the studs 35 and Ml. As soonas this condition occurs it is evident that said studs will beelectrified or cease to be dead, the studs 31 and 33 being of one electrical polarity, and the. studs 39 and as being of opposite electrical polarity. 3

This movement of the armatures 29 and into contact with the studs will generally anticipate actual engagementof the magnet legs with the studs '31, 38, 3s :and 34B, sothat by the time said magnet legs come into actual contact with the studs,'said studs have become electrified. The slight freedom of movement of the magnets within the sockets 43 and 44 wherein they are accommodated is such as to allow said magnet legs to come into good and even contact with the exposed ends of the studs without exercise of great care by the user, so that when insertion of the plug member into the socket unit has been completed good electrical contacts will be produced between the studs and the magnet legs. Thus the necessary connections are eifected through the socket unit and the plug member to place the conductors of the cord 5! into connection with the current supply lines.

As soon as the plug member is withdrawn sufficiently from the socket unit to disengage the magnet legs from the studs 31, 38, 39 and 40 air gaps will be created between the magnet legs and said studs so that great and sudden increase of reluctance of the magnetic circuits will occur, and the spring forces of the spring leaves 23 and 2 3 will at once swing the armatures 29 and 30 away from the studs, thus breaking the electrical connections between said armatures and studs. This will de-electrify said studs, so that they will again become dead and harmless.

Evidently the magnetic attraction between the horse-shoe magnets and the studs and armatures will produce a holding force tending to prevent the plug member from being disconnected from the socket unit. This holding force will be considerable. However, it is desirable to provide for further and greater holding force between these parts, and I have made provision for the same. Thus, in the form shown in Figures 1 to 5, inclusive I have provided the inwardly reaching socket or opening 54 in the end of the plug element 45' the opposite walls of this opening being provided with the inwardly extending ribs 55 and 55. The socket unit is provided with a companion spring catch element 51, carried by the plate 22, so that as the plug member is set into engagement with the socket unit this catch element will enter the socket 54 and provide suffi cient holding force between the plug member and the socket unit to meet normal holding requirements, but will not prevent intentional withdrawal of the plug member from the socket unit.

It is noted that although the studs 31, 38, 39 and 4d are normally dead or Lin-electrified, they become electrified prior to actual contact of the horse-shoe magnets with these studs, since normally the attraction exerted on the armatures 2S and 3!! will become sufficiently great to draw said armatures towards the plugs prior to actual engagement of the magnet legs with said plugs. Likewise. upon withdrawing the plug member from the socket unit the initial break will normally occur between the magnet legs and the outer ends of the studs, since the magnetic flux will not begin to reduce until an airgap has actually been created between the magnet legs and the outer or exposed ends of the studs. However. when these improvements are used in connection with. so-calledextension cords. said cords are usually connected to a current consuming or using implement which is provided with a switch whereby the current is actually turned on and 01?. Therefore when so used the breaking of connection between the magnet legs and the studs 31. 38. 39 and ill does not of itself open the current since such current has already been discontinued use of such a switch as .iust referred to. It'is, however, emphasized that whenever the plug member is disconnected from the socket unit these studs become de-electrified and dead, with the benefits already referred to.

The movement of the plug of the arrangement shown in Figures 1 to 5 inclusive, with respect to the socket unit is a direct forward Or backward movement. In Figures 6 and 7 I have shown a modified arrangement in which the movement of the plug member with respect to the socket unit is rotary. In this case the plug member 58 carries the two horse-shoe magnets (permanent), 59 and 6B, and the socket unit is provided with the two companion armatures 6i and 62 carried by the spring leaf elements 53 and 6c, the arrangement being thus similar to that of Figures 1 to 5, inclusive. However, in the present case the socket unit is provided with the circular flange 65 which is of diameter to receive the base portion 66 of the plug member. The plug memher is provided with the oppositely located lugs 61 and 68 which are adapted to engage with the flange 65 of the socket unit. For this purpose the flange 65 is provided with the two arcuate undercut grooves 69 an It! within which the lugs 67 and 68 will be accommodated; and suitable notched openings 1| and 12 are provided in the flange to permit the lugs 6'! and 58 to pass during insertion or removal of the base portion of the plug member into or from the socket unit.

The lugs 61 and 68 are so located with respect to the notches II and 12, and with respect to the line along which the studs 31, 38, 39 and 40 are located that when the plug is originally inserted into the base element the magnet legs are not in alignment with said studs. Then, by rocking or turning the base or plug member through approximately 30 degrees of turn the magnet legs are brought into engagement with the exposed faces of the studs for the purposes already explained in full detail. Thus the final positioning of the plug member with respect to the socket unit is by a rotating movement. This form of device also is such that as long as this proper alignment exists between the magnet legs and the studs, the plug member is locked to the socket unit, by what may be called a bayonet-coupling arrangement.

The two magnets of the arrangement of Figures 6 and 7 may be connected to the two wires of a cord in the well understood manner. However, if desired this plug member of Figures 6 and 7 may carry the current consuming unit itself. Thus, in the case shown in Figures 6 and 7 and 8 there is an incandescent lamp 73 carried by this plug member, the terminals 24 and E5 of the filament 16 being connected to these magnets so that Such filament is supplied directly with the required current.

Evidently the lamp arrangement shown in Figures 6, 7 and 8, and the socket unit thereof, may be used in connection with a circuit which is provided with a suitable control switch for normally turning the current on and old. However, by use of the socket unit embodying the features of the present invention it is evident that when the lamp element is removed from the socket unit the studs 31, 38, 39 and 4B are dead, so that all danger of short-circuiting or improper connection to the electric supply lines is eliminated.

The alignment of the magnet legs of the ar 7 rangement of Figures 6, 7 and 8 with the studs of the socket unit is by sliding movement, although such sliding is rotary in direction. In Figures 9,1 0 and 11 I have shown another modified'form-of construction in which the sliding antenna movement.- betweem the plug; member: and, the? socketunit rectilinear; Inzthis; casethe; socket; unit includes the studs.31z, 38=, 39 and.43:as before,, and. also includes the two armatures- 1i is carried by the springleaves I9 and 8,0 inmanner similar to that of: the: previously described ar rangements. In the presentcase the plug mem-- ber includes a moulded unit 31 wherein the two: horse-shoe magnets 82 and 83- are carried similar to previously described" arrangements: In: the present case the socket. unit is provided with a straight-line opening-84' somewhat longer than the'plug member unit 81, so; as to permitendw-ise movement of the plug member with respect tothe socket unit- The plug member'is provided with laterally extending lugs 85 and 86 which: may beset down through notches- B l and B8: of the socket unit to bring the face of theplugmember intocontact with or close? to the. surface of the socket unit. The socket unit" is alsoprovided with undercut grooves 89 arrdtilto accommodate these lugs for a sufiicient amount of. endwise movement ofthe plug to'bring the mag-- netlegs into alignment with thestudslil, 38 39 and lil, for the purposeswhich have'already been explained.

Inthe arrangement shown in 'Figu-re-12 the plug member 9.! is. carried by a pivoted connection 92* to the socket-unit 93, said socket unit-beingipro vided with the studs. 31,38,329 and 4i!- and. the plug member 9!. beingprovided with the magnets 94; and 95. The socket unit is. provided with. the: armatures. $6v and Q'Lcarried by the spring leaves 98.. and 99,.in. manner similar to. the arrangements hereinbefore. disclosed.v I

It is noted that in thearrangements of Fig ures 6, '7 and 8', and-Figures 9, lean-d 11, and Figure 12,. the magnet elements are accommodated. within sockets fthe plug: membersof size to. allow some movement of such magnet ole-- ments to enable them to come into good contact with the studs. 31,. 38-, 39 and 451, as will be readily understood. a

Each of the plugs- 8t or 9tof. the arrange'- ments of Figures 9; 10. and 11, or of- Figure. 12', may be provided with wire connections to the; wires of extension cords in well understood-.man ner. Howevenin. Figures 9- and 10 I have; shown cross connections 1.9.0. joining the. two magnets- 82. and 83 directlytogether, and in Figure 12 I have shown the cross. connection [ll-I. joining. the two magnets. 9.4 and 95 directly together; When these cross connecting wires areprovided: these plugs and their. companionsocket units may be usedas switches for controlling. circuits in well understood. manner.

I have already pointed out that" such :ar-- rangements as that of Figures 1, 2, 3-, 4 and 5-the actualbreaking of. circuit, when no: other circuit breaking means is provided, takesplacebetween the magnet legs and the exposed; faces of the. studs 3?, 38, 39 and 49 This would. also be. true; of the arrangements of. Figures 9,.10and L1,, and. Figure 12. When-such devices are to be used. as.

switches, such. action will occur; but generally such deviceswill be. used-in connection. with. circuits which arev provided with other andspecial.

switch means I In Figure 131 have: shown still: another modifled arrangement in which thefactual. circuit making and breaking operations. are effected by, means other than theengagement otthe. magnet. legs withthe. studs31, 38, 39 and 40. .Inthecase of Figure 1.3 the socketunit I02 isprovidcdwith two studs Hi3 and l 04 reaching. through the-..wall-.

8. I; ofithe socket unit; and: saidwall also carries the two additional contacts 10% and H11 whiclr are insulated. from each other and constitute-the: two terminalsof the'circuit to be switched. This; arrangement alsoincludes thearmature IOBcarried by the spring leaf H39; and this armature? also; carries the two movable contacts H0 and I l I connected by the wire 11 l and which are in-- sulated from the armatureas shown in the figure.

: In. the case of Figure I3 I have provided themagnet H2 which is movable towards and from the socket unit; and the legs'of this magnet moveinto alignment with the studs I03 and I04 so: that. when the magnet is close to the socket-unit;

.; the studs are magnetized and the armature. is.

drawn towards the magnet, that towards. the wall I05 of the socket unit. As this occurs the: armature; carried contacts engage the stationary contacts toclose the circuit; and vice versa, as

= the magnet-is moved away from the socket unit the armature is released, and is withdrawn by the leaf spring, to thus open the circuit. The socket unit of this arrangement may be provided" with a housing H3 which provides, in connec-- tion. with the. wall Hi5, a water tight enclosurefor the movable parts andfor the contacts, both stationary and movable If desired the enclosure. N3. of Figure 13 may be filled with oil or other suitable electrically insulating liquid to thus provide an oil-switch arrangement by use of. the construction of that figure.

In Figures 1 and 2' I have shown the springs: l M and H5 located behind the magnet elements; 41 and 42, respectively, saidsprings being in the; form of leaf springs anchored to the plug body 2!, and having their free ends pressing against said magnets. These springs therefore exert-a. slight pressure tending to move the magnets towardsthe studs 31, 38, 39 and 40 when the plugv member is engaged with the socket unit, so as; to ensure good contact-between the magnets and: the studs. It is noted that the pig-tails 41 and. 48 have a slight stiffness tending to retain the magnets back away from the crossmembers 45 and 46 but in case such stifiness should befound. excessive, tending to prevent good engagement-oi, the. magnets with the studs. when. the plug member isv brought into engagement with the. socket. unit,.these springs H4. and H5. may be-made of sufiicientstrength to ensure good. engagement'of the magnets with the studs to give good. electricalcontact betweenthese parts.

It. is notedthat in. each. of the embodiments; hereinillustra-ted the magnetsareshown as being.v carried by themovableelement,,previously designated as the plug and. the. armatures. corresponding-to these magnets are. shown. as being. carried by the. stationary element, previously designated. as the. socket. It. will be evident,v

: however, that this, arrangement might. be. re.-

versed thev magnets. being. carried by the sta.-, tionary element, and. the armatures being carried. by the movable element.

It willbe noted that in the embodiment. shown in Figure 13 there are. shownonly two stationary. contacts, we. and I01, and two corresponding. contacts Ill), and HI carried, by the armature. "18.. However, the. number of such. contacts. may be either greater or smaller than shown, as. for example,,three or four, or more stationarycontacts, and a corresponding. number of, movable contacts. 7 a

It is. also noted that each of. the embodiments herein. illustrated provisionhas been made.

5. fortwo. conductors which are controlled for Gilli-r.

cult opening and closing purposes. It will be evident, however, that each of these embodiments might be provided with either contacts for a single conductor, or for more than two conductors, for example, three, as in the case of making provision for a three phase circuit, or for a three wire system of distribution;

While I have herein shown and described only certain embodiments of the features of my present invention, still I do not intend to limit myself thereto, except as I may do so in the claims to follow.

I claim:

1. A detachable electric fixture comprising in combination a socket element and a companion plug element, said socket element including a partition of insulating material, two pairs of studs of magnetizable material extending through said partition, two leaf springs corresponding to said pairs of studs and located at one side of said partition and having their anchored ends secured to the partition and their free ends in proximity to the corresponding pairs of studs and normally retracted from said studs by the bias of said leaf springs and movable towards said studs against such spring bias, a magnetizable armature carried by the free end of each leaf spring in position for energization by magnetic flux flowing through the corresponding pair of studs to thereby draw said armature into engagement with said studs when said studs are magnetically energized to thereby electrically contact said armature with said studs at such time, and electrical terminals in connection With said leaf springs, and said plug element comprising a housing, a pair of permanent U-shaped magnets individually movably mounted within said housing and electrically insulated from each other and said magnets being spaced apart to correspond to the spacing apart of the pairs of studs, and the poles of each magnet being spaced to correspond to the spacing of the studs of the corresponding pair of studs, the poles of said magnets facing outwardly from said housing and being directly engageable with the ends of the studs opposite to the stud ends engageable by said armatures aforesaid to thereby establish electrical engagement with said studs, and to subject the studs to magnetization by said magnet poles, whereby when the plug element is brought into position with respect to the socket element to register the magnet poles with the studs magnetic influence is transmitted through the studs to draw the armatures into engagement with the studs to thereby complete electrical circuits to the magnets from the electrical terminals aforesaid, and whereby the U -shaped magnets are individually movable into contact with the corresponding studs, together with electrical connections from the magnets to suitable delivery lines.

2. A structure as defined in claim 1, together with means to limit the movement of each magnet with respect to the housing.

WILLIAM McLEOD.

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

UNITED STATES PATENTS Number Name Date 1,778,481 Boucher Oct. 14, 1930 1,978,065 Twombly Oct. 23, 1934 2,044,948 Leon June 23, 1936 2,234,982 Ross Mar. 18, 1941 2,298,313 Ross Oct. 13, 1942 2,448,832 Ross Sept. 7, 1948 2,474,942 Hawkins July 5, 1949 FOREIGN PATENTS Number Country Date 865,035 France Feb. 10, 1941

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