US2269171A - Electric switch - Google Patents

Description

Jan. 6, 1942. v BENANDER 2,269,171

ELECTRIC SWITCH Filed May 18-, 1939 Fig.1.

M450; kr/o/v Ihventor: George B. Benandeh,

by )Va/wyd.

His Attorneg.

t ei-Patente dfJah. 6; 1942 1 The present 'inventionueifrelates to v switches," andiit is an object,off.this'fl ,to provide an; improved=switch;ScbnsttuctioxiLWhich is durable inuse and,'1at'thersamevtimeeisimple site end ofa the uitablefrbearvide a novel construction? and-rearrangement for" w securing a cover and vmounting straprtoYa-switch :flcasmg. K I Further objects and adv'antagespf that-present" invention will become apparent as the ollmiving I description proceeds; referencefibeing 'had ;to the 's'tationaryi contact 'nd iterminal'st'ruw accompanying clrawingsin which Fig .1? i'suasplan t ybythetnurii "l nveom- .-'view of an electricswitchzembodying,theapresent' Lp gleesheet met tampi'n having a invention;tFig.' 2: is' 'an v'elevationals view' n-' +sc'-'-' fand p tionvof-the-switchof. Fig. .1 ;liafid'iFigf: 3 5 fan exploded vievvrim perspective showing thezdet'ails "of the switchconstruction. Y

-In the embodiment-of myinventiohiilustrated in the 'drawing a'body is? recessed ramane face .and provided .with a 'cover I lflto r-form a housing .for; the switchingsi mechanism. -.:The housing is preferably a molded 5 from any 'suitable insulating material fsuch" as a phenolicsicon'densa tion 'product. vThe .oppositeside'l walls-ofeth f z recess are provided withvalig'nedgroov' es ='ll='.which open I on the: recessed face iof theibodyiiand r are shaped toprovide bearing surfaces for" pivotally mounting an operating lever l3iandvaimovable contact structure 1 illustrated -ge-n'erally b'yei the numeral I4. 1n theupresent constructio'n*-the 1 movable contacts'structure comprises savzflsingle sheet metal stamping ofgoodconducting material' having axpair ot spaced":parallelzizblades l5 formed with contact portionsrilfi'iat'their op"- posite ends. I Theblades arerconnected'rtogether by a substantially Ushaped'bridgingi portion l1, An integral trunnion I8=-'extendsQIateraIIyTifmm the central "portion-of each of the blades I'Sa'and .is positioned in the V-shaped bottomipontionI 9 of oneof the-grooves [2mTher'operatingm'nem ber 13 which may also' b'e rformed of-=?mo1ded insulating material extends throughia-n:openiiig' 2 0 in the cover H and:is providedawitlt'a'a ipair of f laterally extending cylindricalatrunnitmsv l -which' are received inhsuitable curved bearing. surfaces 22 .formed' at the -upper zends aof thec:groove12.

The cover H .is provided .withiisuitable'zisemicircular bearing v surfaces :23 adjacent; the-aside wallsv of the opening and in; alignment lwi'th the :upper' ends ot the grooves |'2.- Theubearing surfaces :22 and 23'rcooperate'r mount" the three-.waiyi switc lidstratedxinthe Y allymorma 'rniin'al strip stampingawat: generally: shape. 1th paced" threaded i openings' 'forii the rs-reception of suitable"-(bindingvscrewvs'32" fo'r' lsecuring iresftotheivterminahlafrhe contactiand fthe'igcasing v GZ fOImEdi iD' the: en'd of: thessbottomwwall 1 .0 the body: an-d: prevents I "en'dwise move- I the: contactzistructure': relative to the "ody An-integral In 138 "extending from the.

i posite end "as the: temninaljstrip vprojects h'rou'g-h 'an opening? match 39 viin' the'cover nd' has *its outer: endtbent'tover into engagementtwith the shoulder ztolclam-p the cover gainst thei recessed iface' -o the switch fl rbody.

:Th'e;ashoulder '40=wisupreferably 'recessedirom the pperi- 'surface of thefcover l'l-, *sor thats the end I the r lug w'il1 hotriiiterferezwithamounting the 'llhezvother stations; :JQ-COl'ifiECbI-Eflhd terminal tructu're ish' simi lar t tha titjust-described but formed in twompieees which .are'=;mountedin nsul'ated relation inwthe oppositeiendof :the.

asin'gzn Thei-lowerstt'ermihalt:I I12; anducont'acts 42,

v are secured to the1 svvitch ib0dy ini thetsame manoperating lever for oscil1ationfi-aboutaitszatrunn'er aaas.z=that '-described rconnectio'n;withrthe nions when the cover is:securedito thefbodyu "An ontact structure'128 b wedgeas-haped lug 35 over-center'- compression spririgflk isapositiond andl cooperatingsirecss"36'1A -'I%he::-.terminal-4 I.;=- like of the lever.

' "-4 terminal strip 29, is provided with a threaded opening for the reception of a suitable binding screw 32 for attaching the bared end of an external circuit conductor to the stationary contact structure. Another terminal 43 with a pair of extending contacts 44, similar to the upper portion of the contact structure 28, is mounted above the terminal 4| and separated therefrom by a plate ofinsulating material 45 having edge extensions 46 which are positioned between the end wall of the casing and the ribs 33. In order to secure the terminal 43 and contacts 44 in the casing, a plate 41 is secured to the outer surface of the terminal strip by a binding screw 48. The plate is arranged to engage a shoulder formed on the end wall of the switch; body by one of the openings 49 which are formed in the opposite ends of the switchbody to provide access to the terminals for the purpose of making the necessary circuit connections therewith. The plate '41 is provided with an integral lug 50 which passes through an opening 5,i in the terminal 43 and engages the inner surface thereof to prevent the plate from falling out should the binding screw 48 be removed. The terminal 43 is provided with a lug 38 which extends through a notch 39 in the cover and is bent over into engagement with a shoulder 40 in the same manner as the lug 38 of the terminal strip 29.

With the stationary contact and terminal structure described above, a three-way switch is provided. A single pole switch may be provided bymaking both stationary contact structures similarto that designated.by numeral 28,

, but-with one structure having the upper conto the switch casing. Integral ribs 53 formed on the bottom wall 31 of the switch body reinforce the same and aid in positioning the shields 54. In the extreme positions of the movable contact structure an edge of the bridging portion I! thereof engages one of the shields which acts as a stop. The shield is more resilient than the molded body and as a result this arrangement providesa much quieter'operating switch than those in which an integral stop lug is provided on the switch body.

The present invention also provides a novel arrangement for securing a mounting strap to the switch casing. A mountingu strap 56 havtantially the --'width of the switch body is pro 'ded with a ture l4 from one position to another with a snap action through the action of the over-center spring 24. stick so that the pressure of the over-center spring is not sufficient tostart the movement of the movable contact structure, a positive driving connection between the operating lever and the movable contact is provided. The operating lever isprovided on'its opposite faces with lugs 52 which are molded integrally therewith and lie on opposite sides of the axis of oscillation The movable structure is provided with shoulders 53 which extend slightly above the trunnions i8 and lie in the path of the lugs 52 when the operating handle has been moved through its center position without moving the movable contact structure. As clearly indicated in the drawing, the shoulders 53 face in opposite directions so that a different one of theshoulde'rs is engaged by one of the lugs 52 when the operating lever is moved in opposite directions.

In case the contacts of the switch In order to reduce arcing and increase the life of the contacts, a substantially U-shapecl shield 54 01 insulating material is provided for each of the stationary contact and terminal: structures. As illustrated, the shield is formed of suitable sheet insulating material and positioned between the pairs of stationary contactsextending from the terminal plates 29 4| and 43. The free edges of the U are normally spaced slightly farther apart than the distance between contacts so that the tendency of the shield to unfold holds the arm portions thereof in engagement with the inner surfaces of the stationary contacts and aids in positioning the shields with'respect parts which are ve plurality of inwardly extending integral lugs 58. The. lower face. of the cover II is provided with .notches 59 extending inwardly from itsopposite edges and spaced to receive the lugslof the mounting strap. The notches arepreferably of the same depth as the thickness of the lugs 58 so as to provide a flush mounting. It is of course possible to form a portion of the notches 59 in a portion of the upper face of the switch body or, to provide'the notches entirely in the 'switch body. With this arrangement it is only necessary to position the mounting strap on the \cover with the lugs 58 positioned in the notches 59 before assembling the cover on the switch body. When the cover is fastened to the body the mounting strap is tightly clamped therebetween and prevented from movement with respect tothfe switch body. The construction-described above requires few easilyass mbled. It will be noted that no a ditional fastening means are required to mount the stationary contacts in the switch casing or to secure the cover to the switch body. The construction-also simplifies the assembly of the switch and mounting strap. What I claim as new and desire to secure by Letters Patent of the United States is:

ative to said casing, a lug projectingfrom the .other stationarycontact structure, a cover positioned on said casing and having an aperture at each end to receive the lugs projecting from the other endof the conducting strip of said one contact structure, and said lug projecting from v the other contact structure, said last-mentioned lugs having portions thereof bent into engagement with anouter surface of said cover to .-'hold it assembled \on said casing.

2. In an electric switch, a body of insulating material recessed from one face, stationary contactlstructures. positioned in said body adjacent the'opposite ends thereof and secured against end ise movement, a mounting strap having an opening therein positioned on the recessed face of said body withat least a portion of the walls defining said opening extending over a portion of the recessed face of said body, a cover positioned on said body. integral lugs extending from oneend. of each of said contact structures and having engagement with an outer surface of said .positioned on said body,

tending along an contact structure stationary contact structures assembled on said body.

r 8,269,171 cover to hold said cover and saidmounting strap 3. In an electric switch, a body recessed from one face, stationary contact structures positioned in said body adjacent the opposite and secured against mounting strap having-an opening therein: and a plurality of integral projections extending inwardly from the walls of said opening, a cover the recessed face of said ends thereof 7 endwise movement, a-

body and the lower face of said cover being shaped to provide openings for the reception of the inwardly extending'projections of said mounting strap, and an integral lug extending from one end of each of said contact structures and engaging an upper surface of said cover to hold said cover and said mounting strap assem-- bled on said body.

4. In an electric switch, a body of insulatin material recessed from one face, a cover of ,in-

s'ulating material positioned on the recessed face of said body and cooperating therewith to form a housing, a mounting strap having an aperture body with a portion of the walls defining said aperture overlying the face of said body, said housing being recessed at the junction of said therein positioned on the recessed face of said body and said cover to receive the overlyingporv tion of said mounting strap, and means for securing said cover to said body and for clamping said mounting strap therebetween.

one face, stationary contact and terminal struc-' tures positioned in said body adjacent the oppo- 1 site ends thereof, each of said contact and terminal structures including a a supporting strip extending along an end having contacts extending in spaced parallel relation, U-shaped shield of insulating material positioned between said contacts and having the opposite inwardly therefrom arm portions thereof in frictionalengagement with the inner surface of said contacts.

6. An electric switch comprising a cas n stationary contact and terminal structures posii tioned in said casing adjacent the opposite ends and a substantially electric switch, a body recessed frorn' g wall of said body and lever 1 extends," and an integral lug projecting from one end of each of said stationary contact structures having a portion thereof bent .into engagementwithan outer surface of said cover to hold said cover on saidbody and the trunnions of said operating lever and saidmov- 1 able contact structure in said aligned slots.

8. An electric switch comprising a casing, stationary contact structures positioned in said casing-adjacent tneopposite ends thereof, each of said structures including a supportingstrip extending along an end wall of said casing and having contacts extending inwardly therefrom in spaced relation, a movable contact structure of substantially U-shape mounted in said casing for oscillation with respect thereto and arranged toconnect electrically certain of said. stationary contacts in at least one of a plurality of operative positions, means for moving said movable contact structure fromone position to another with a snap action, said movable contact structure including spaced contactarms resiliently engag-.

ing certain of said fixed contacts in the closed circuit positions of said movable contact structure, anda member of sheet insulating material of substantially U-shape positioned between said stationary contact structure and constructed and arranged to limit the oscillating movement of said movable contact'structure and to diminish sparking between the contact portions of said fixed and movable contact structures as the con- .tactportions thereof are separated.

9. An electric switch compris ng a casing, stationary contacts secured in said casing adjacent the opposite ends thereof, a movablev contact structure mounted for oscillation with respect to said casing and arranged to connect certain of said stationary contacts in at least one of a pmrality ofoperative positions, means'for moving said movable contacts from one operative position to another with a snap action, a member s of sheet insulating material positioned in said casing adjacent each end thereof and so constructed and arrang ed with respect to said movthereof, each of said contact and'terminal structures including a conducting terminal strip exend wall of said casing and having contacts in spaced relation,

said contacts and a movable contact structure mounted for'oscillation with respect to said casing and having a portion for engaging one of said shields in each of its extreme positions to limit-the oscillating movement thereof.

7. In an electric switch, a material recessed from one face andprovided on opposite side walls with aligned slots, a movable having laterally extending trunnions positioned in said slots, an operating extending inwardly therefrom v a substantially U-shaped shield of insulating material positioned between able contact structure as to engage the same in each of its extreme positions to limit the oscilinsulating materialalso being so constructed and arranged withrespect to the contact portions I lating movement thereof, said members of sheet of said stationary contacts andsaid movable contact structure as to engage the contact portions of. the latter during movement thereof from one circuit controlling position to another tangula'r body recessed from one face thereof,sta-

body of insulatin lever having laterally extending trunnions posii tioned in said slots abovethe trunnions a: saw

movable contact structure, a compression spring interposed between the inner end of said operating leveriand said movable contact structure,

positioned insaid recess adjacent the opposite ends of said body and secured againstendwise movement relative to said body, a coverfor said body having an opening therein through which said operating tionary contact structures positioned in said body adjacent the opposite endsthereofleach of said stationary contactzstructures including a termivnal strip extending along an end wall of said bodyuarid having integral contact members ex tending'inwardly into the recessed portion of said body, each ,of said contact structures also having an integral lug projecting from the recessed to cool said contact portions and diminish spark- 10. In an electric switch, a substantially recf faceof said body, means forsecuring said contact structures in said body against relative end'-- wise movement with respect thereto, and a cover positioned on said body, said lugs being ,bent

into engagement with an outer surface ofsaid cover to hold it assembled on said body.

GEORGE" B. BENANDER.

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