US2857485A

US2857485A - Multi-position electrical switch

Info

Publication number: US2857485A
Application number: US618020A
Authority: US
Inventors: Brooks Russell
Original assignee: Martin Co
Current assignee: Martin Co
Priority date: 1956-10-24
Filing date: 1956-10-24
Publication date: 1958-10-21
Anticipated expiration: 1975-10-21

Description

do 219 R. moon@ POSITION ELECTRICAL SWITCH MULTI Filed Oct. 24 3.956

INVENTOR wi @www nited States Patent MULTI-POSITION ELECTRICAL SWITCH Russell Brooks, Towson, Md., assignor to The Martin Company, a corporation of Maryland Application October 24, 1956, Serial No. 618,020

9 Claims. (Cl. 20G- 6) This invention relates to a multi-position electrical switch, and more particularly to a switch of the wobble disc contact type.

In many electrical systems it is desirable to provide a single switch which is capable of making and breaking a variety of different electrical circuits with extreme rapidity. In most circumstances in which such characteristics are desirable, it is also desirable for the switch to be as compact as possible, and sealed in such a manner as to insure against interferences with operation due' to the entrance into the switch body of moisture, dust or other contaminating matter. Previous attempts to satisfy the need for such a switch have been switches which if suiciently compact and capable of a large enough number of Contact `positions, could not be operated rapidly, did not 4engage and disengage the Various contacts with detiniteness, and could not pass rigorous humidity tests.

In many instances, it is very important for a multiposition electrical switch of this type to have definite operating characteristics in all positions, for the switch operators attention may be concentrated on something other than the operation of a switch. As an example, the operator may be watching a display upon a cathode ray tube, such as may be used in conjunction with a radar set. In such an instance, it is most important that the switch have distinct feel characteristics so that the operator will be enabled to detect `the making or breaking of a particular circuit, and to be cognizant at all times of the exact position of the contacts of the switch. Existing switches of the multi-position type have been found to require high operating forces with attendant slow speed operation, to` lack satisfactory feel characteristics, and generally to be somewhat limited in the manner in which the operating lever of the switch can be moved from one operating position to another. v

It is, therefore, a principal object of this invention to provide a multi-position electrical switch which enables a variety of electrical contacts to be rapidly engaged and disengaged in a delinite, snap action manner.

It is another object of this invention to provide a multiposition electrical switch which, because of the relatively small forces required to manipulate the operating lever of the switch, and other constructional advantages possesses very sensitive feel characteristics.

It is still another object of this invention to provide a multi-position electrical switch in which substantial force is exerted in engaging and disengaging its various contacts, but in which the sensitivity of the operating lever can be varied to meet individual needs.

It is a further object of this invention to provide a multiposition electrical switch in which the operating lever can be rapidly moved from one contact position to another without it being necessary each time for the operating lever to be moved through a neutral point.

It is a still further object of this invention to provide a multi-position electrical switch which is compact, simple in design, and which is sealed so that it will operate yICC satisfactorily without electrical failure under extreme environmental conditions, including high humidity.

A multi-position electrical switch constructed according to this invention comprises a central distribution contact and at least three fixed electrical contacts arranged in a spaced array about the distribution contact. The distribution contact has at least six flat side edges,'with alternate side edges aligned with the fixed electrical contacts. A wobble disc is located upon the distribution contact, and is arranged to tilt upon any of the flat side edges. The wobble disc is equipped with a flange overlying and normally spaced from the fixed contacts, and means are provided to selectively tilt the wobble disc upon a at side edge to bring the flange into operative engagement with at least one of the fixed electrical contacts. The disc, when tilting upon one of the alternate side edges that is aligned with an electrical contact, is brought into operative engagement with only that contact, and when tilting upon a side edge intermediate two of the alternate side edges is brought into operative engagement with two xed electrical contacts.

An operating lever may be employed to move the wobble disc to the positions desired, and the lever is equipped with a spring urged plunger that is biased into iirm engagement with the wobble disc, thereby to bias the lever and wobble disc to a neutral position in which the wobble disc is out of engagement with the fixed contacts. Because of this wobble disc bias and tilt arrangement, the wobble disc has a definite snap action as the operating lever is moved to and from each position.

A guide plate is preferably provided adjacent the operating lever, and a number of lever-receiving recesses are provided in the guide plate. The positioning of the recesses is related to the positioning of the xed electrical contacts, and are of a number equal to the number of the fixed contacts. While the operating lever is freely movable between its various operating positions, the guide plate is nevertheless effective to stabilize the operating lever in certain operating positions, so that the wobble disc is stabilized in each operating position either by being in engagement with two electrical contacts, o1' because the operating lever is in engagement with a recess in the guide plate.

Further objects and advantages of this invention will be more readily apparent from the following description, when read in connection with the accompanying drawings in which:

Figure 1 is an elevational cross sectional view of the switch;

Figure 2 is a top plan view of the distribution contact;

Figure 3 is a side elevational view hof the distribution contact;

Figure 4 is a sectional view taken along line 4 4 of Figure 1; and

Figure 5 is a diagrammatic view showing the relation of the guide plate to the lixed contacts arrayed about the centrally disposed distribution contact, and revealing symbolically the mannerv in which contact is made between the centrally disposed distribution contact and either a single fixed contact, or simultaneously with two iixed contacts.

The switch according to this invention includes a distribution contact 5 and fixed

electrical contacts

1, 2, 3 and 4 placed in a spaced array about the distribution contact. In the illustrated arrangement, the contacts are preferably located on one end 7 of a hollow housing 7 that may be cylindrical in shape, and open at the other end. The housing 7, including end portion 7 is preferably made of plastic or other non-conducting material, and the contacts are in sealed relation to the housing.

A peripheral ange 8 is formed about the upper surface of distribution-contact5,and as illustrated in Figs. 2

through 4, f the JAper-ipheraliiange` 8- hasaenumberv of4 flat side edges t. As revealed in Figure 4, alternate side edges 8' are placed in aligned relation with the ixed contact. points 1,2, 3v and 4-,--^while"theside edges lintermediate the alternate side edgesare in alignment with points that would be midway between any twofixed contacts. While fthe preferred Aembodiment shows eight side vedges and rfourfixed contact points, itis to-be understood that six side `edges` and threecontacts--points, or another even -number of-side edges and'half asmany contact points :could be successfully employed -in `accordance with this invention.

- IA wobble Adisc 6 `is mounted upon the distribution consired. A lower hub 9 is centrally provided on the lower ;surface=of WobblediscI-,` and this hub titsv within a recess ISlocated inlthe upper-surface ofdistributionfcontact 5.

This .insures thetcorrect positioning of lthe \wobble disc in the desired location atop the distribution contact. 'The hub 9 is undercut Yto a diameter suiciently'lesslthan'the 4inner diameterzof recess SQthatthe disc16can be 'freely `moved with respect to thedistribution contact, into engagement with any of the tixedcontacts.

The wobble discm6 extends upwardly and' outwardly from its central portion `insomewhatof a conical manyner, and'ont'the underside of-theiperipheryA of the-disc Vis -a metallic contact .ring or'ange '10 that extends entirely about the periphery, of the'dise .The iiangel 10foverlies the tixed contacts 1' through 4 and isY normally spaced -therefrom, but as the ywobblediscis tilted, the `liangerl will -be moved intoelectricalfengagementwith any contact, orinto simultaneous engagementwith-two adjacent contacts.

. An operating lever: v1S :is mounted 1in`housing 7 'directly above wobble disc^6, sotthatthediscmaybemovedinto the desired position of'engagernentrwithithe fixed contacts.

An enlarged or ball shaped portion 14 is provided on .the operating lever adjacent theendfoflthe'levernearest lthe wobble disc 6. This' ball='shaped"'portion..isi rotatably mounted in ball socket; 28, which -islcreated betweenvball retainers 12 and 13. The ball retainers are closely tted into the upper -or open end `of-the housing andan-encircling shoulder 27 is provided on the inner surface of the side oftheI housing' to..forma';support forthe'ball retainers. socket 2S, and as it is moved in one direction, this-.causes a countermotion of the' lower extension'17 of theloperating lever, across the fulcrum formed by the ball shaped portion inball-socket 28. Therefore, `by appropriate movements of -the operating leverjthe wobble `disc may be moved freely -intoanypositiondesired. An operating buttonl is -provided lon the 'upper endoftheoperating lever: 15,2'and1. thisl button ismaintained infthe desired location by meansof-a suitable set screwt'l.

The surface of wobble disc 6 opposite the hub'-9 is provided with a conicalsoeket11,which maylbearcuate butfwhich ispreferably substantially` parabolicfasv shown. A `plunger 19 of hard plastic or other finsulating'mate'rial is slidably mounted in :a suitable= recess. inextension 17, and isbiased by` compression spring'lSrinto firm-engagement with v`socket 1-11. Because `of the spring Vbiased plunger and its `interactionwith thersocketllfwhen 'the operating lever `is released, it willcenteras shown in Fig. 1 to' hold the wobble disc 6 in the flat, centered-position in which it is out of engagement with all of the xed The lever is universally movable in ball contacts. When the operating lever is manipulated to one Vaf-its "angular eperafing pesitions, the 'plunge `A19 'will ride up on the concave surface of the conical socket 11, and will cause the wobble disc to be tilted upon one of the flat side edges 8 so that the tiange 10 will be brought into engagement with one or more of the fixed contacts. At this time, a selectedvcircuitwill be completed to effect the desired operation.

It is to be noted that whenithe operating lever'has been moved to a deflected position, the spring 18 is compressed to a greater extent than when the switch is in its centered position. This compression of the spring causes the wobbledisc'to `be heldagainstltheselected contact or contacts with relatively high pressure, which insures good electrical contact with a minimum chance of arcing. It is also to be noted that with this construction, a snap action of the disc is produced both during the making and the breaking of a circuit, due to the fact that the wobble disc will' tilt sharply ,upon a fiat-side edge 8 in onedirection or'the other as soon as'the line of force exerted by plunger 19 crosses the edge upon which the wobbledisc lis-tilting.

To insure stabilityl for'the switch when the operating lever 15 has been moved to bring the wobble disc'into 'engagement with a single fixed contact, a guide plate -21 is'providedin "the upper portion of the housing 7,'and an`aperture'22 is located in the central portion of the guide'pl'ateg through whichthe operating lever 15 extends. 'The ap'erture22 is formed in such a manner as to provide a numb'erof lever-receiving recesses 22', the Anumber of recesses ybeing dependent upon'the number of yfixed contacts, 'and'in' this Vinstance'being four in number.

'These recesses ZZare placed in a definite orientation 'with Arespect'to 'the fixed contacts, and inasmuch as the operatingleverIS moves in the opposite directionv to 'the directionof `the contact with whichthe wobble'disc is making^"engagement, .the recess that corresponds to a particular xed contactis located" away 'from that contact. In yother words, referring'to' Figf'S, if the operating lever 15 is movedinto anyofthe cardinal positions :A,.C, E or G, the'wobbledisc willbe caused'tot'ilt'into engagement with-fixed contacts"3,"4,"1, `or'"2, respectively.

Also `indicated on the guide plate"'21y are 'theiitrmediate positions B, D, F and H. When'the 'operating lever -has -been-rnovedto one Aof these positions,"the` wobble ydisc is caused to be Amoved intoengagerreirtwithtwo lixed cont-acts simultaneously. Y"A 'study'of'Fig'S `will re- `v'ealthe various contact -relationshipsithat 'canv'be obtained vby 'the use of the present switch. As an example, when theoperating lever "has Ybeen movediinto position I-Li the'wobble -disc V6 moves'so "asto bring contacts 2 fand 31intoelectrical engagement with the distribution contact-Tias is indicated -in -the 4lower right-hand corner of Fig. 5.

The construction of the ywobble disc-contacty arrangementis such that by maintaining his finger on the Voperating button--16,-'the operator can sense vthe position'of the wobble disc` at' all times. -Wherr the Ioperating llever has been lrnovedto an intermediate'fposition `so-as to cause the wobble disc 6 to tilt'pon an intermediate edge 8',"the flange 10 comestore'st upon two fixed contacts, thereby toform a tripod The'biasof plufnger1'9 is suiiicient that thewobble disc will llite-moved to and from lthis tripodconiiguration with quite-abit ofdeniteness, which is responsible for the factthatthe operator can feel'tsuch movements of the `wobble disc. Thisvconstruction, in conjunction with the-'provision of the guide plate for guiding the operating lever when it is desired to engage va single Contact makes it possible for the operator to move theswitch into any and` all of the positions desired without any substantial amount of concentration on the operation being necessary. Furthermore, the operating lever need not be returned tothe center or'restpositioneach time, for the switchcan-be moved from' onel position to another, or-even'through Vall'eight positions l'seriatim Awithoutit being necessary to cause the operating lever to pass through the position indicated in Fig.' 1;

Since it is understood that different operators will have varying desires as to the sensitivity of the switch, according to this invention the operator may adjust the compression of spring 18 so that the wobble disc will be caused to engage and disengage the fixed contacts with a desirable amount of force. To this end, a centrally disposed adjustment screw 20 is provided in the central portion of operating lever 15, and since this screw is in operative relation to the upper portion of spring 18, by adjustment of screw 20, the spring 18 may be adjusted to the desired amount of compression.

Suitable sealing arrangements are provided so that the switch according to this invention will be environmentally free. As previously mentioned, the contacts in the bottom 7 are in sealed relation and ball retainer 13, which rests upon shoulder 27 located around the interior of the housing 7, is provided about its periphery with an Oring 31. Suitable grooves or recesses are provided on the periphery of retainer 13 and on the interior of the housing so that the O-ring can be seated very tightly. Further, a seal 26 is provided about the periphery of retainer 12, and a cup shaped resilient seal or boot 23 is provided intermediate retainer 12 and guide plate 21. The central portion of boot 23 is provided with an aperture to receive the operating lever 15, and the boot is preferably sealed to the lever, such as at point 24.

The guide plate 21 may be maintained in the desired position in the upper part of the housing by means of two or more screws (not shown) that extend radially inward through the cylindrical walls of the housing and threadedly engage suitable threaded holes provided on the periphery of plate 21. Preferably these switch components are so arranged that the lower fiange 30 of boot 23 will be tightly compressed between the upper face of ball retainer 12 and the lower face of guide plate 21 at point 25 to provide a good seal. In addition to sealing the operating lever against the entrance of moisture into the switch, the lboot 23 prevents undesirable rotation of the operating lever 15 about its axis, for the boot 23 would become wound up when such rotation tended to take place.

The ball socket 28 and the ball 14 are preferably provided with an aluminum alloy hardcoat and lubricated by a suitable application of molybdenum disulfide or molybdenum disulfide in a resin binder. This method of lubricating eliminates the need for any further lubrication during the normal period of the usefulness of the switch.

To facilitate the attachment of an electrical conductor to the distribution contact 5, a suitable fitting such as a screw 32 may -be provided on the underside of this contact. through 4 preferably extend below the bottom 7 of the housing, and similar fittings are provided on these lower portions so that all of the contacts of the switch can be electrically connected to the circuitry in which the switch is to be used.

In the operation of this switch, the operator moves the button 16 in the direction of one of the eight positions indicated on the guide plate. The motion of the operating lever causes a resulting countermotion of the extension 17 across the fulcrum formed by ball 14 rotating in ball socket 28. This countermotion causes the plunger 19 to move away from the center of the conical socket 11, located in the upper portion of wobble disc 6, and -to ride up on the concave surface of the socket. When the line of force passes the edge of peripheralfiange 8, the wobble disc is caused to pivot or tilt upon a fiat edge 8 until the fiange or peripheral area 10 of the disc comes to rest on two fixed contacts in a tripod arrangement or comes into engagement with a single contact. The particular engagement with the fixed contacts, of course,

The lower portions of the fixed contacts 1 f depends upon the position into which the operating lever is moved. When the wobble disc is moved into engagement with a single fixed contact, Ibecause of the presence `of guide plate 21, one of the recesses 22 is available to stabilize the operating lever 15, and this in turn causes the wobble disc to be stabilized in its tilting about the fiat edge 8' that is aligned with a single contact.

This construction in which fiat undersurface 46 of the wobble disc pivots upon the fiat sides 8 of the peripheral flange 8, in conjunction with the spring biased plunger arrangement provides a snap -action of the switch as it is moved into the position desired. When in an operating position, the wobble disc 6 provides a good current path between the distribution contact and the fixed contact or contacts engaged by the peripheral flange 10.

When the `button is released, the plunger 19 tends to return to the bottom of the concave socket 11, in which position the spring 18 is in a less compressed state. This causes the wobble disc to be snapped back into the neutral position, with 4a minimum of arcing taking place between the peripheral flange and the fixed contact or contacts.

Modifications of the present invention will be apparent to those skilled in the art, but it will be understood that such modifications are within the true purposes and the scope of the following claims.

I claim:

l. A multi-position electrical switch comprising a distribution contact, at least three electrical contacts arranged in a spaced array about said distribution contact, said distribution contact having at least six fiat side edges, with alternate side edges laligned with said electrical contacts, a wobble disc located upon said distribution contact and arranged to tilt upon any of said fiat side edges, said wobble disc having a flange overlying and normally spaced from said electrical contacts, and means to selectively tilt said wobble disc upon `a flat side edge to bring said fiange into operative engagement with at least one of said electrical contacts, said disc when tilting upon one of said alternate side edges in alignment with an electrical contact being lbrought into operative engagement with only that contact, and when tilting upon a side edge intermediate two of said alternate side edges, being brought into operative engagement with two electrical contacts so as to provide three point support for said disc.

2. A snap action multi-position electrical switch comprising a distribution contact, at least three electrical contacts arranged in a spaced array about said distribution contact, said distribution contact having -at least six fiat side edges, with alternate side edges 'being aligned with said electrical contacts, a wobble disc located upon said distribution contact and arranged to tilt upon any of said fiat side edges, said wobble disc having a iiange overlying and normally spaced from said electrical contacts, means to selectively tilt said wobble disc upon a fiat side edge to bring said flange into operative engagement with at least one of said electrical contacts, said disc 4when tilting upon one of said alternate side edges in alignment with an electrical contact being brought into operative engagement with only that contact, and when tilting upon -a side edge intermediate two of said alternate side edges, being brought into operative engagement withl two electrical contacts, and means biasing said wobble disc to a neutral position in which it is out of engagement with said fixed contacts, whereby said switch will have definite snap action as the wobble disc is moved to and from each tilted position.

3. A multi-position electrical switch comprising a central distribution contact having an upstanding peripheral flange with at least six iiat side edges spaced therearound, at least three fixed contacts arranged at spaced intervals about said distribution contact, alternate side edges of said peripheral fiange being aligned with said fixed contacts, a wobble disc supported by said peripheral fiange distinse v-and arrangedA to tilt upon any of said fiatside 'edges, said 'disc'havingl a 'peripheral area overlying land I normally A:spaced f romsaid fixed `contacts', 'an 'operating' lever arranged fto' engage said discto selectively tiltsaid disc 'upon :a 'flat side'n edge lof 'saidid'ilstribution contact'sdas to "'bring' said'pe'ripheraliaifea in t 'operative engagement 'with at least one of said fixed contacts, and aguide plate 'ad- "jacent said operating `llever,"saidguide' platefjhaving a :nu'r'nber of lever-receiving recesses therein, thposition- 'ing of said recesses being related` to"th po'sitioninghr "said Ifixed Acontacts and Abeing of' a"nu`rnber equal to the "number" of Ysa'id iixed contacts', said operating lever being freelyx movable between allj operating fpesitioneand'being stabilized 4by said1 'g'uideplate vt/ henbeingpp reted .'jso as to cause sa'idwobble' disc to tilt upon one of 'said 4'alternate' side edges, saidfdiscwhen tilting upon a side "edge intermediatetwo of s`aid'alter`r'iateI side edges being stabilized 'by engagement with "two orsaid fixed con- 4. A snap Iaction multi-position electrical switch com- 'prising' a central'distribution zcontact having 'an upstanding peripheral flange with at A least six fiat side ed'ges spaced'therearund, at least three fixed contacts' arranged a t"spaced inte'rv'alsab'out said'distribution contact, alterfrane sidev edges' of said priph-eral 'aange-'being aligned with said fixed contacts, a wobble disc supported by said peripheral fiange and arranged to tilt upon any 'of said fiat sideed'ges, said discfthaving'a' peripheral area overlying-and'norrnally spaced from' said fixed contacts, an operatihgflever arranged to'selectively tilt said disc upon ing a 'spring urged plunge( biased into frin'engagement with said wobble disc, saidlever and wobble disc thereby 'being biased to va neutral position in which said wobble disc is out of engagement'withsaid fixed cont-acts, and -a guide 'plate adjacent said loperating lever, said guide 'plate having a number of Alever-receiving recesses therein,

'the positioning of 'said recesses being related to the posi- 'tioning of said fixed contacts and being of a number 1eq'ual `tof 'the number ofsa'id fixed cont-acts, said operating lever being freely movable'A between its various operating positions, and being stabilized by said'guide plate v'when being operated so' as to causesaid wobble discwto tilt upon one of said .alternate side edges, said disc, when tilting upon 'aside' e'dge 'intermediate two of said alternate side edges being Ist'abilied by"engagement with two 'of said fixed contacts.

V5. Themulti-p'osifidn electrical's'witch asvdefined in 4claiin 4 fi'n 'whichmcans a'r'e provided fof modifying the force with vvh'ich said plunger is'biased into engagement withsaidfwobble disc,'whereby the sensitivity of operation 'of said switch can be'altered.

6. nin i-fpo'sitio'n electrical switch comprising a housing, a'dis't'r'ibutin 'contactinounted insaid housing, said distribution 'contact having 'at least six fiat side edges, at least'threee'lectrical contacts mounted lin said housing and 'arranged in a spaced array about said distribution contact, alternate side edges ofsaid distribution. contact being aligned with said electricalpont'acts, a wobble disc supported 'by said distribution contact and arranged to tilt upon any of said fiat side edges, said 'wobble disc having a lfiange overlying and normally spaced 'from said l iixed contacts, and an operating ,lever-projecting into s'id housing and mounted therein for universal angular movement, said lever being arranged to 'engage said disc4 so as to tilt it'uponone of said fiat side edges of said distribution contact to bring the fiange of said wobble "disc intoenig'agement with at least one of said electrical contactsand aguideplete for said operating lever, said l `nber'oflever-receiving recesses thereinQtheY positioningl off said reoessesbeing related to "the positioning of said'electrical contacts in said housling, 4and'b t'eingio'f number *equal to -thenumber of said electrical.'contacts,"said operating lever being Astabilired byfsid guide' platewhen said lever is beingoperated so astro' case'said :wobble discntoilt upon one of said alternate side edges, said disc when tilting upon a side edge'intermediate twomof said alternate side edges being stabilized by engagement with two of said electrical contaCt5 l -lu 1.1-,

The'niulti-position electrical switch las defined in claim' 6 in whichsealing means are provided between said guide plate and said housing, and surrounding .said operating lever'aty the location wherein it projects into said housing, lto prevent theentry of dust and moisture. 8. The multi-'position electrical switch as defined in claim in which means are provided to prevent dislodgment of said wobble discfrorn said distribution Contact.

9. AV snap action multi-position electrical switch cornprising a housing, a central distribution contact disposed in said housing, said, distributioncontact havi'ng anupstanding peripheral flange Withiat least six fiat side edges spaced therearound, -at least `three fixed contacts mounted in saidhousing'and` arranged at spaced intervals :about said distribution contact, alternate side edges of said peripheral fiange lbeing aligned with said fixed contacts, a wobble discsupported by said peripheral fiange'and arranged to tilt upon any lof saidflat sideedges, said disc having a conical socket centrally disposed on i'its upper surface, and a peripheral area overlying and'normally spaced from said fixed contacts, an operating lever disposed ina location directly above said disc and arranged ,to selectively tiit said disc upon a fiat side edge'of said ydistribution contact so as to bring said peripheral area into operative engagement with vat least one of'said fixed contacts, said operating leveruhaving a spring urged plunger biased into firm engagement with said conical socket, s'aid lever and wobble disc thereby being biased to a neutral position in whicth said wobble disc is out of engagement with said fixed contacts, and a guide` plate adjacent said operating lever, said guide plate having a number of lever-receiving recesses therein, the positioning of said recesses being related to the positioning of said fixed contacts and being of a number equal to the number of said fixed contacts, said operating lever being freely movable between its various operating positions, said guide plate being effective to stabilize said operating lever when said wobble disc is being pivoted upon one of said alternate side edges, whereby said wobble disc is stabilized in each operating position either by 'being in engagement with two electrical contacts, or by the operating lever being in engagement with a recess in said guide plate, said switch, because Iof said wobble disc bias and tilt arrangement, having a definite snap action as the operating lever is moved to and from each position.

References Cited in the 'file of this patent UNrrnDsTATEs PATENTS