US2427015A - Push-button switch construction - Google Patents

Description

sept. 9, 1947.

C. MILLER PUSI' BUTTON SWITCH CONSTRUCTION Filed June 5, -1946 MINI:

INVENTo Cf//P/JTA/AA/ /7'/ Ee Patented Sept. 9, 1947 2,427,015 PUSH-BUTTON SWITCH CONSTRUCTION Christian Miller, Norwalk, Conn., assigner to Edwards and Comp any, Inc., Norwalk, Conn.,

a corporation of New York Application June 5, 1946, Serial No. 674,454

Claims.

This invention relates construction.

One of the objects of this invention is to provide a push button switch construction that can be made of individually simple and inexpensive parts and capable of ease and dependability of assembly. Another object is to provide a push button switch construction the parts of which can be assembled with facility and dependability in the form of several sub-units, and the subunits in turn assembled in a simple and reliable manner. Another object is -to provide, in a push button switch construction and more particularly in a structure of the so-called flush type, dependable features of structure and assembly for dependably maintaining certain movable conductive parts electrically insulated from certain other conductive parts, more particularly the conductor-connecting element or elements. Another object is to employ, in structures of the above mentioned kind, parts made of non-conductive material and constructed so as to be capable of simple and inexpensive production as by molding, and still-shaped to achieve, in assembly, the desired co-action with other and conductive parts.

Another object is to achieve a small and compact switch construction which will be of strong and durable construction and of dependable and long-lasting electrical action. Another object is to provide a flush type of push button switch structure, capable of being set into a hole in a wall or the like, in which, though dimensionally restricted;l good and lasting guidance of the manually movable part o-r parts and good electrical action may be achieved. Other objects will be in part obvious or in part pointed out hereinafter.

The invention accordingdy consists in the features of construction, combination of elements, and arrangements of parts as will be exemplied in the structure to be hereinafter described and the scope of the application of which will be indicated in the following claims.

In the accompanying drawing in which is shown by way of illustration a preferred embodiment of my invention.

Figure 1 is a front elevation of an assembled push button switch, certain parts being broken away to show certain other parts in central vertical section;

Figure 2 is a bottom plan view as seen from the bottom in Figure 1;

Figure 3 is a transverse sectional view as seen along the line 3-3 of Figure 1;

Figure 4 is a detached front elevation, partly in central vertical section, of a sub-assembly that comprises the push button and a contacter, with the mounting of the latter to the former;

to push button switch Figure 5 is a plan view of a known conductive element of the push button switch structure;

Figure 6 is a plan view of a sub-assembly comprising contact and connector elements and their mounting, and

Figure 7 is a central vertical sectional View as seen along the line 1 1 of Figure 6.

In the accompanying drawing similar reference characters refer to similar parts throughout the several views.

Referring first to Figure 1, I first provide a casing or shell IB which in the illustrative embodiment is preferably made of metal such as sheet metal and is shaped or drawn to provide a cylindrical side wall II of a diameter somewhat less than that of a hole drilled into a door-frame or wall and into which the ultimate switch button switch is to be set. Such a hole may be on the order of 5/8" in diameter. rThe upper end of the shell I0 is provided with a laterally extending flange I2 which serves to limit the entry of the structure into the hole of the wall or doorframe and it may be given a curved configuration as shown. At the lower end of the side wall II the shell I6 is shaped to have an inwardly directed horizontal flange I3, leaving a relatively large circular hole Ill, and `at suitable and preferably diametrically opposed points the ange I3 has extensions in the iform of bendable ears or lugs shown in section in Figure 3 at I5 and I6 and in Figure 2 being shown bent over as in the nal assembly.

Where it is preferred that the structure be yieldably or frictionally held in the wall hole or door-frame, I provide a suitable friction or gripping device which comprises a suitable member, illustratively 4, of spring arms Il which are integrally formed, as by stamping and bending, with a ring-like frame I8 which has radial dimensions to just mate with and underlie the bottom shell flange I3, as is better shown in Figures 1 and 3, so that the upwardly bent spring arms Il extend upwardly (in Figure 1) along and externally of the wall II of the shell I 0, thus to be positioned to react, by their spring action, with the casing wall II and the wall of the -hole in the wall or frame to hold the structure securely but releasably in place. As shown in Figure 3 the ring frame I8 is cut away as at I8a and I8J to snugly accommodate and intert with the ears I5-I6 which thereby center and align the fastening device I'I-IB with respect to the shell I0 and particularly the bottom flange I3 of the latten Thus these two parts are easily put together in the process of assembly of the entire structure.

The cylindrical wall I I serves as a guide for slidably receiving `therein a button 20 (Figures land 4) which is preferably made of any suitable moldable material or socalled plastic, such as,

for example, Bakelite, and depending from the button 20 (Figure 4) is a stem 2l which is preferably of metalandconveniently inthetform yof a stamping of suitably heavy sheet metal suchas brass, being in configuration preferably as shownv in Figure 4; thus it comprises a relatively long'` shank 2l terminating at its lower-end in 'a cross r The upper cross part 21 is partially embedded in the button 20 and preferably the two are secured'togetherbyrmoldin'g and curing the material'ofthe 4button"2()"onto Iand about the major portion 'of the crossV part '2I, the latterbeing appropriately notched in its vertical side edges, as indicated in Figure 4, to insure good-mechanical interlock between the two parts; For these purposes the thickness and transverse dimensions ofthe crossparts 2lb andV 2Iarev preferably thesame so that the stem 2 I can be inserted into the correspondingly dimensioned lrecess in a wall of the mold, leaving the-entirey bottom cross-piece 2 Ib neatly `iriter-iitted with the mold recess and bottoming therein to' lan extent to project 'the major portion of the upper'cross part' 2 Ic into the mold cavity. leaving a minor portion 2I thereof within Vthe "mold recess' and: inter-tted'therewith, the parts'2 ib'and vZIf thereby neatly aligning the stem'" at rightangles to 'theface of the'mold cavity against' which the'button 28'is then molded and'interlocked; leaving -the minor portion 2li of the-cross part 21, in the final sub-assembly, projecting Vdownwardly* below theunder face of thebutton 20,-as is clearly'shown in Figure 4.'

With the parts' ZII-and-2Iy assembled; there is now slipped over the stem -2I a `spiral-helical springl 23 whose uppermost porti-on is of a diameter to receive therein this downwardly projecting'portionlfvof the upper'cross part 2IC, thereby, 'and thereafter, u aligningy the Vaxes of the spring 23A and stem 2 I'. Against the lower turn of spring 23 is-then'positioneda disc-like contactor 24 which can be in the form-cfa simplev stamping yof-sheet metal, preferably springy; it has a-diameter materially less'than that of the shell4 we'llI I- and `is provided-with aA central hole 25`surrounded-by a depending ilange-25, all

dimensioned appropriately toipass thelower crosspart-Zlibfreely therethrough, for A assembly lpurposes, Against the under face #of contacter 24 and about the iiange-2 5% rests the upper turn -or endA of' a helicalspr-ing 2'uflwhichr isrsleeved over the crossfpiece 2 Il and which-'coacts'to hold the disc 24'1Iagainst' detrimental. laterali f shift. Spring 26v has one or more lower end turns'(as indicated in Figure 4) 'of a diameter less than the width o1" theacross k.parti 2Ib, over which these turns are sprung `oriexpanded during assembly and against' the-upper edges -of which they thereafter Lbear so that spring 261 can exert upward Aforce against the f contactor 2 II and: against `the downward force of .the spring .23,the strength ofthe springs being such thattogether theynormally hold the contactor 24-iust about'midway of-the -endsofv the shank 2111.T Thisisubunit, asV shown -in Figure 4,

is now ready tube-assembled to -the--restof thestructure.

The-contactorLZA is tol serve as a circuit-closing element -to bridgetheirelativelylxed lcontacts of theiswitch structure. In the illustrative embodimentl provide: tvvospacedv contacts arranged 'to' be exposed internally of the shell I0 and in the path of downward movement therein of the contactor 2. Preferably theseconta'cts are diametrically opposed on a diameter materiallyless than `the diameter of the contacter 26, and I prefer to mount them in a relatively heavy disc-like base- .plat'e' '2l made' of. any suitable non-conductive material and preferably of any suitable moldable plasticr Base-plate` 21 is preferably of substantialthickness and has a diameter about the same as that ofthe shell Ill (see Figure 1), and in appearance is in leffect a downward extension of the latter. In its upper face (Figure 1) it has a circular recess 28 (see also Figures 6 and 7) of uniform depth, peripherally bounded by the thin walled rim or flange 21e of the base-plate 21, and

the upper edge face (Figure 1) of thepart 21a' is adapted to rest against rthe ring frame I8 and is thus supportedagainst the shell flange I3. Spaced inwardly from the rim flange 21a,- baseplate 2l has two'rectangular apertures 3D and 3I (Figures 6, 7 and v2) which are diametrically opposed and dimensioned snugly to receive therethrough the ears or lugs I5, I6 of the shell I0', the

under or outer face of thepart 2I being providedA with radially extending recesses 32 and 33 into which the apertures 3D and 3I respectively open so that when the ears I5 and IS -are ultimately bent over as shownin Figure 2, the bent-over portions oi the ears are accommodated in these external recesses andl thus need not project beyond. the plane of the outer end-face of the base-V plate2'I.

Thek base-plate 21 .I alsov provide with two spaced rectangular` apertures 34 and 35 spaced along a diameter (see-Figure 6) that is at right anglesv to the diameter alongwhich the abovef described apertures 30 and 3I` are spaced. The spacing between apertures 34 and 35 is materially lessthan the diameter of the contactor 24 (see Figure 1) and the diameter of the latter is also materially less than that of the shell wall II, the parts beingso proportioned that any :unintentional lateral shift oi the contacter 24 relative to the stem 2l. does not bring the contacter 2d into. engagement withithe .shellwall and does not bring it out of a position where it overlies both apertures 34 and 'ifrom which project upwardly the contacts 315i` and 31 respectively which the contactor 2G bridges upon depression of the button 2G. The contact -38 is integrally formed, as by stamping, out of suitable sheet metal such as brass, which is stamped to provide a wider part 38 in which is provided a threaded hole to receive a binding screw d!! by which an electrical conductor may bemechanicallyy and electrically connected, and. intermediate of the parts 36 and 38 the stampinglislprovided with a shank portion l2 which is oila width intermediate of the width of the partsti` and 38, as is better shown in Figure 7.A It is the shank part 42 which is tted in the aperture 34, the Wider external part 38 providing shoulders to limit the extent ofV entry of' the stamping through the aperture 34 land thus accurately to position the end-face of the contact part 3`relative to the part 21.

The contact 37 is formed out of a similar or identicalk stamping vand' has an outer' wider Apart 39 with a threaded hole in it to receive the bind ing screw 4I (Figure i): and van intermediate shank portion t3 ofH intermediate width that is intertted with'the aperture 35:

These 'stampings are held Yin the member 2T by' stampings, Vor by 'laterally expanding the lefthand shoulder ends of the intermediate or shank portions, as indicated in Figure 7 and also in Figure 6, and thus hold them in place.

On the under-side of member 2'! as viewed in Figure 1, and integrally formed therewith, is a downward extension 2lb which is conveniently square in bottom view as seen in Figure 2 and in horizontal dimension as seen in Figures 2 and 6 it is preferably equal to the spacing between the apertures 34 and 35, so that its two opposed external side walls 21 and 2f are in alignment with the innermost Walls of these apertures and provide a strong and rigid support for the two downwardly and externally projecting connecter portions 38 and 3Q (see Figure l). This extension 2lb of the part 2l thus also gives the latter greater thickness and strength throughout its central portion (see Figures 1 and 7) and within this greater thickness is formed, as by molding, a rectangular and deep well 44 (Figures 7, 6 and 1) which in cross-section (Figure 6) is dimensioned to neatly and slidably receive therein the bottom cross part 2|b (Figure 4) of the button shank 2|. That cross part 2lb is rectangular in cross section, and hence the well $4 (Figure 6) is also of rectangular cross-section with its major axis on the diameter along which the contacts 33, 37 are spaced.

The three parts shown assembled in Figures 6 and 7 form another sub-unit or sub-assembly and co-aCting therewith is a disc-like member 45 of non-conductive material conveniently in the form of a stamping of hard bre or the like, Member d5 (Figure 5) is stamped out in the form of a disc dimensioned to be neatly received in the above described circular recess 28 of the part 2 and to substantially lill that recess (see Figure l), and it has cut-outs 452L and 45b diametrically opposed and dimensioned to coincide or register with the ear-receiving apertures 33 and 3| respectively of the part 2l (see Figure 6). Aligned along the diameter along which the cutouts 45a and 45b are spaced is a rectangular hole 45C of the same dimension as the cross section of the end cross part 2|b of 'the button shank 2|, so that when the part 45 is seated in its recess 28 alignment of the cut-outs with the apertures 30 and 3| and the subsequent passage therethrough of the ears brings the hole 'i5c crosswise of and at 90 tothe open end of the well i4 which the disc member 45 otherwise overlies.

The Width of the hole 45 is at least equal to the width of the shank 2N of the button stem 2| so that, once the cross part 2lb has been passed through the hole 45C, the button and stem assembly can be rotated 90 and thus bring the cross part 2 |b to extend crosswise of the elongated hole 45 of the disc pari; 45.

The sub-unit, as shown in Figure 4, may now be inserted in the upper end of the shell Il against the under ange I3 of which the ring frame I8 has been placed as above described. By thus appropriately projecting the free end of the shank 2| below the plane of the ring frame I8, the disc element 45 is now slipped over the end cross part 2|b to enter the latter through the hole 45c and also to somewhat compress the springs, bringing the disc part 45 up against the under side of the ring frame I8, the ears I5 and I6 entering the cut-outs 45a and 45b and thus fixing the position of the part 45 relative to the shell. An appropriate turn of the button and stem assembly about its axis now brings the end cross part 2|b at right angles to the major axis of the hole 45,the shank 2|@ being freely accom-V modated in the hole 450 fori purposes of such turning. To either sideof the hole. [l5c the disc part 45 is provided .Withholes 45Vf and 15g spaced and dimensioned to freely vreceive .therethrough the contact elements 36 and 3l which project outwardly from the member 2l Vandiwhich Yare vof a length (Figures 1 and 7) materially greater than the depth ofthe recess 28. Y l

The sub-unit or sub-assembly of Figures 6 and 7 is now brought into position, and due ito the above described relationships it cannot be finally assembled to the rest of the parts unless the major axis of its well 4'4 is at the required angle in the illustration) to the major axis of the hole 45c in the disc 45. This relationship of as# sembly is assured by reason of the relationship of the ear-receiving holes 30 and 3| to the' cut-outs 45 and 45b through which the ears already ex.

tend as above described, and also by the relationship of the holes 45t and 45g to the contact elements 36 and 31, the latter not passing through these holes unless the required relationship eX- ists. Thus simple and fool-proof assembly is made possible.

The part 2l takes over the disc 45 Awhich is snugly accommodated in the recess 28 ofthe former and part 45 and the rim part 27a, together abut against the under face of the rim frame I8 whereupon the bending overl of the ears I5 and IS clamps all of these parts in flnalassembly re-v lationshipi The button 20 forms an upper guide in co-action with the shell Wall for the reciprocating movements manually brought about upon ldepression and release of the button, and the cross part 2 Ib forms, in co-action with the Walls of the deep Well 44, a dependable guide for the lower end of the button and stem assembly, and thus the circuit-making and circuit-breaking down and up movements of the contactor 24 relative to the contacts 35 and 3l remains unaiected by manual thrusts applied to the button in other than a true axial direction. The two springs yare so proportioned that they normally hold the con-` tactor (see Figure 1) above and out of contact with the contacts 33, 31 and so that a rst portion of the button depressing movement eiects a yielding or compression primarily of the lower spring 26 sufficient to cause the contactor 24 to bridge the contacts 36, 31 and the ensuing portion of the button depressing movement thereupon effects a major compression of the upper spring 23 to apply increased pressure of engagement of the contactor with the contact elements, equalized between the two, by the action of the spring. During these actions the springs can exert some torsional stress upon the contactor 24, tending to give it a slight rotary movement and hence a rubbing and self-cleaning action against the contacts 36 and 31. Also, if desired, the contactor 24, if made of a spring material and relatively thin, can partake of some dishing under pressure and thus also contribute to a self-cleaning and rubbing action. These actions may also be benecially derived out of slight lateral displacement of the contactor 24 relative to the stem shank 2 la, under the stress of spring pressure against the xed contacts.

Upon release of the button, the end crosspiece 2 Ib, guided upwardly along the well 44, abuts against the under face of the disc part 45, extending crosswise of the hole 45e, and thus limits the movement of thebutton 20 outwardly of the shell I0 to the desired extent and, in co-action withfthe springs, holds thecontacter 24 in the-dei sired open-circuit position. The bottom end of thewell' Mwill be seen'to be "closed ol (Figures 1 'and 17)., thus v1precludingthe entry `ol` foreign matteriinto thestructure and thus also precludingthe exposure from the structure of 'conductivewparts other lthan the conductor connecting parts '38;40' and 39-4l. Moreover, 'the well 44 co-acts with the end cross 'part' 2lb to prevent thefbutton 'and stenrzlassembly from rotating about zits' axis and Lthus it Vfis impossible tobring trie? cross part` 2 lbf into alignment with the holev 45tand thus=t11e fassembly roi. thestruo'ture 'is dependably: maintained.

It willi thus 'be'seen lthat theref-has 'b'een 'prlo'` vided iniwhis'inventioi `fa str'ucturein which the' various objects above noted,- together Iwith -m'any thoroughly 'practical advantages; :arefsuccessfully achievedi'f .Asimany possible embodimentsmay be 'made-of the -faboveiinvention 'fandas manyV 'changesmiglrt beQmade in the embodiment iab'ove' set forth,v itis torpe' understood' thatY all matter" hereinbefore set 'forth-*jor shown in" the accompanying drawing is to be interpreted as illustrative yanlinot1in-a limitinglsen'se;

I claimt -1. util-pushv button 'switchr constructionf comprisingva, shellfhayinga 'bottom' wall' providedwith a well otflohgated cross-'section rand-'opening intdtheashe'll, said bottom wall having 1a irecess in its upper face peripherally bounded bya flange-likelportionffof the'. bottom wall,` a v'plurality for connector-contact' means" extendin'g througnsaidbottomwallandinsulatedfromeach other fanufhaving ithe contanti portions thereoi exposed .lnteriorly aofthelshelhl a button? for entry int'oi's'aidshellandhavingfa depending stein pro-- vided fat :its lower-Send with la cross part-of! clon"- gated crossisect-ion- @for :entryf finto' said l well,l l a plate member'receivedfi'n? said' recess-and having an aperture?oflelongated -cross-sectioii'for the passage th'erethrc'n'rg'fhV of saldicross-partgsaid pltememberlbegpo'stired *soV that the maior axis 2 of A its i aperture" is ALat' an angle to' the" major existen-the 'cross-section'lof tnelwell, therbyto prevent said eross-partrtrom riding upwardly and' outwardly ffroinsaidwl-lplfarid v-a conta'ctoi" associated withsaidlbutton toco-act-iwitli said conoppos" ingd'epression .of-th button; relative to"v the' snella@ 2. "A t push buttonr i' swit'ch f construction l as Vclaimed-'in claim l inYwh-io'h Psald'A bott'omwalliSv-a means securing-said bottom wall'to fsaidlshellbl 3; `A push@ f buttons. switch construction? I. `as clair-neuf in claim-y i1, in= which '-'saidf 'fplatef'meiiiberhascut'mutmeans for rco-action" with at least one of said: connector-contact means l to hold: the piateimember against rotary-'displacement relative-to san'd'fwelland*- therebyf maintain theaforesaidfanguiarl relation betwe'enfsaid tw'omajor axes-1- 4.'A f push "button switch constructior'iVYV as claimed in1claim= 1 in which` the f porti'om of said bottom: wallecontainingiisaid Well-comprises a downward' *centralrextension of -f the materialil of the bottom Wall to expose exteriorlyltlrereoflateral-:faces said connector-contact inansnaving thefcon-neotor portions thereof engagingV against said lateral-faces.

comprises a coiled spring substantially vcoaxial withsaid stemand having its lower end -turn constrict'ed about said stem to an internal dimension less than the major yaxis of 'said crosspart, saidv spring abutting at its lower 'end against said plate member.l

6. '-A push button" switch construction as claimed in claim 1 in which theV button end of saidstemcomprises a cross-part of a cross-section substantially the same -as that of said first cross-partgsaid Asecond cross-part having a major portion thereof entered and secured into the button and havingl a minor portion thereof projecting' below the under-face of the button, said spring means comprising a coiled spring having an upper endY turn received about said projecting minor portion of said second cross-part to thereby substantially center said spring.

'7. A push button switch construction comprising' a metal'shell having a cylindrical side wall, a 'bottom 'member of insulating material having a substantially central guide-way of elongated cross-section,` said bottom4 member having extending therethrough and insulated from' each Vother thereby a plurality of connector'-` conta'ct elements with the contact portions thereoiexposed internally of the shell, a push button having a depending stein provided at its lower end with a cross-piece of elongated cross-section for entry into said guideway, a plate member interposedbetween said bottom member and the real end oi the shell and having an elongated apertureA therein for the passage therethrough or said cross-piece, said plate member overlying said bottom member with the major' axis of its aperture makingY anangle with the nia-jor axis oi the cross-section of said guideway to thereby hold said stem from upward movement out of said guide'way, a contacter associated with said button for coaction with'said contact portions, spring'means opposing depression of said button, -and means 'holding saidbottom member, said 'plate'memben and said4 shell together.

8. A push button switch construction as claimed in claim 'l' in which 'said plate member is-provided with cutouts to substantially interfit with saidV connector-contact means and thereby hold said plate member against rotary displacement to prevent its aperture from becoming aligned with said guideway.

.Q -'A push button' switch construction as claimed in claim l in which saidspring means comprises two coiled4 springscoaxial with said stem' andl said contacter comprises a metal platelike 'element having an aperture rthrough which said stem extends, said plate-like element being interposed between the adjacent end's of said two springs.

l0. A push button switch construction as claimed in claimV 7 in which said springmeans comprises two coiled springs coaxial -with said stem'and saidcontactor comprises va metal platelikeeienient'having an aperture through which saidptem extends, said 'plate-like element being interposed between 'the adjacent ends of said two springs', the end turn 'of the Vspring that is adacen't'th'ecross-part of said stein being constricte'd tov a dimension less thanv the major dimension of 'said cross-part whereby said buttonstem, springs, and contactor form a subass'embly; saidend turn of vsaid spring abutting against saidV plate member;

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