Contact-spring switch assembly

Jan. 5, 1954

J. I. BELLAMY ET AL

CONTACT-SPRING SWITCH ASSEMBLY Original Filed April 10, 1943

2,665,352

Sheets-Sheet 1

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INVENTORS: JOHN I. BELLAMY RICHARD P. ARTHUR

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ATTORNEY

I

Jan. 5, 1954

J· I. BELLAMY ET AL 2,665,352 _ . CONTACT-SPRING SWITCH ASSEMBLY

Original Filed April 10, 1943

Sheets-Sheet 2

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INVENTORS:

JOHN I. BELLAMY

RICHARD P. ARTHUR

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ATTORNEY

Jan. 5, 1954

J· 1. BELLAMY ET AL

CONTACT-SPRING SWITCH ASSEMBLY Original Filed April 10, 1943

2,665,352

Sheets-Sheet 3

Fig. 9

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Rg.I ΙΑ °~²³

INVENTORS^

JOHN I. BELLAMY

RICHARD P. ARTHUR

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' ATTORNEY

Patented Jan. 5, 1954

2,665,352

UNITED STATES PATENT OFFICE

2,665,352 CONTACT-SPRING SWITCH ASSEMBLY John I. Bellamy, Wheaton, and Richard P Arthur

Corporation, a corporation of Maryland ** ^appli9^at*^on April 10, 1948, Serial No

Ι^Ιθδϊ,δβΚΝο^ΐΙ®^{8 aPPUcation Ma}rch (Cl. 200—166) j 5 Claims.

This invention relates to a contact-snrino· switch assembly. The principal object is to^PproreiyIⁿaId^SoX^y ? X ^{tyPe SUitable for use in}It nr 2^{d ther structu?,}es which make efficient

This annllT ^they °^{CCUPy on a} switchboard. This application is a division of our now abanApril^d10^aPi^P948^ati°^{n Number 20}’¹⁹⁶&gt; ^filedof^?»°b^ieCt I^{s t0 provid}e a switch assemblv of the loregoing character capable of being used support^ ^{mounted close} together along a common as^rnbR ^ewh°irh ^{Ct iS t0 PTOVide a compact} switch assembly which is rugged m structure and effitilXtXl ^f°J ^convenient operative associa- ™ lion with cooperating parts in relay structures.

GENERAL description switch assembly is herein disclosed in &lt;ts with Xb^WI^{h re}L^{ay structures}· ^The structure 20 with which it is shown in particular utilizes a bai-hke magnetic member as a common supporting means and common magnetic return member £ ΧΛ ^{48 dM}»“^a· XX ,^S ί ^L-shaped cross-section to conform to 25 use ^c°ⁿsti’uction of relays for switchboard use. Rs shape provides sufficient rigiditv and strength to enable it to serve as the support ^Ι0·^Γι^{a compara}tively long row of relays, ne proolem encountered in providing relav “Χ?±^ηΧ7^ηΐ18ί0^™- 86 ⁸^J ^{g apd} adjusting the contact-making Sbiucuures of the several relays of a row in the comparatively limited space allotted to each in a compact arrangement. This problem is as ™ ^{8d by}X ^{fact that the} contactomlktog 35 rtiuciuies oi the several relays in a row auite numb°ⁿ³all^{ry Widely amongst} themselves Is to numb.,1 and arrangement of contact-making pares contained therein, thus necessarily requirZs toXlX? ? ^ST^{mbly and a}djustment 40 ™n thP ^act^m&lt;^{akmg assem}blies located V-tiun the s^me row of relays. In the present structure, this problem has been laZ? Ξ stepped by providing structure enablinf the con and by providing structure enabling the actual ’ mg portions^! the relays to be readily adXsted ,;θ °_x^{nform t0} the assembled positions of the re- 50 iirpartI^reT£^Up^tedi^aT^mbli88 °^{f con}t^act-mak10 tn ii^ac°^ompapyⁱⁿS drawings, comprising Figs f,.¹'¹?⁸·.^{1 to 3 are} respectively, top, rear and «:dXn^at^Strip °^f according toX ofV^{S 3 SeCtl0nal view} taken line 4-4 ^{aeM m the} »· »»«&lt;&gt;»« ηΒ?' -I ^{and 6}’ ^show- ^resPectively, a plan view £^SS. ^{Of the} co^act-making assembl? ΐίηΤ/τ ⁷₇^{and 3} are views taken respectively along SUr ^,_i °' ^Ηε· ^β·^wlth Χ “ί thXX.¹⁰·^10A· “^{&lt;1 1IA sl}&gt;™ or

DETAILED DESCRIPTION allv^h? ΖθΐΧ ^{haVing been} described genernowbe gllen ^{deSCription of the} disclosure will

Al. General structure

In the drawings, magnetic angle bar E serves as a common support, and as a common mag to arew ^membe1’’ ^f°^{r relays moun}tod therein

Referring particularly to Figs. 1 to 3 each r° lay includes an electromagnet c, its armatu™ D, a switch asembly E actuatable by th? Xοτ Tiqt’ Ι-i ature, and the portion of bar B occupied by these parts.

Angle bar B, as shown in Figs 1 2 and t b_Q&lt;, ing the ΧΧΧΙθΧΐ ^reE_ai^P“'^{ti0n support}-’ _{ot a} SX* ‘° ‘”0 mS? i” fear itat. „ positions of the parte d Λ?*⁰”^{8 and dis}’ merely relative. ’ ^{f01 the most part}· oo&gt;=t at the _Wp” ΪΧΧΤοΪβ X downwardly extending front portion „ ?' ^{h8 p}°™^tte'»» «O' to

2,665,352 ably so disposed, as shown in ^pig;\^hat they make about equal angles with parte; 2J ;

The smooth working surfaces of such aims bear against the bent portion of armature D to.prevent its upward or forward displacement. As-shown in Fig. 1. lateral movement of such armature is nrevented by the rounded side portions of tne member Ϊ4 This method of mounting the armatare insures its reliable operation when mounted KTdlired attitude. Similar previouslyknown armature-retaining members required expensive milling: and grinding, whereas ^aP^pli^t^smember is punched and formed of sheet metal with a smooth side -thereof forming a bearing surface, for the retained armature. _

A -U-shaped residual plate 23, shown in Figs. 11 and 11A, is applied to armature D and then crimped in place to appear as shown in. Figs. 3 and 4. Such an applied residual plate, when em ployed lies between the core and the armature. Bv striking-the-core, -it holds, the arma.uure Qut-of contact ither.ewlth .to. insure that a desired amount of the operating:-air. gap remains: unclosed with the -armature in its fully operated position.: Tins unclosed portion of the operating air gap is commonly, referred to -as -the residual air gap.· Its length -determined iby the tJiickngss of plate controls a release characteristic of the relay, as is commonly .known.

It -is •contemplated that the relay armatuies will be provided in lots, distinguished -by .specifically' different residual-gap lengths assigned thereto, varying from zero to about ,020 inch, for example. One lot will have -no residual plate and will therefore provide no .residual .gap. The remaining lots will have residual plates of respective thicknesses. Each ..armature of a lot will carry a symbol indicative of the thickness of the residual plate-23 attached thereto.. For example, the.first armature to the left in Fig. .3 is marked “15” to indicate that its residual plate is fifteen thousandths .of .an inch, to provide a residual gap of .that -length between -a fullyrc-perated armature and its core 4.

A2. Switch assemblies.

For convenience, the switch assemblies (shown at -E) are illustrated as being all alike. Ordinarily, the assemblies vary from relay to relay according to the different circuit functions of the different relays. The assemblies may vary in the number of types off sets contained therein, and in the -number of sets of any one type, from which .it follows that they may vary, in overall number of contact sets and in the height of the pileup, as will be readily understood,

Referring now to Figs. 5 to 8, the detached switch assembly E shown therein may be the one shown applied to any one of the.relays illustrated in-Figs. 1 to 4. Such switch assembly includes cap plate 32, base plate 33, and parts clamped between them by -screws -34, which pass, through openings in the cap plate and intervening parts to the base plate wherein ..they are threadedly received. Two-opposed columns 30 and 31 of contact sets are included in the same unitary assembly E. This construction enhances rigidity and reduces the number of assembly and clamping screws-required. .

Referring now to Fig. -6, wherein the left-hand column 31 is respectively shown in profile to include four commonly denoted types of contact sets, the make-before-make set (fixed blade 55 and traveling -blades 56, 57), the break-make set (fixed blades 58,63 and traveling blade 59), net C for attraction upon energization thereof. Effective attraction rotates the armat ₂₍ upon rearwardly extending lifting Port ion 2 r moves upwardly to operate t?e associated sw^h aecpmblv E Upon deenergization-of-&gt;ne position by the tension of the traveling ma c «*.·-* if 1-wfc

SS'received ν,ΙΙΐώ an opening In the of bar B, rendering it longitudinal^ adjustable.

A locknut 3 is provided to “ · desired longitudinal position ^pf.^™^en;i_{d is} ' Each coil 5 loosely enciraes .itscore 4, and provided with a square rear spoolhead 7, and ^r°BearwardlT“Si —* “T'^Sfor each coil 5, are located in a row along the lower edge of rear spoolhead 7, :the^jsquareoutu. of which retains the coil against rotation. SSX portion ol any te»l ” krent out of engagement with bar B by anunsu iSng spaJlng «Bar ». wBoh onolrelca core « between the bar and rear spoolhead 7.

Dmtag-assembly, coil « is slipped °ve™e 4, to the position shown in Fig. 4, P™r ' ^P^ned tion of the.associated armature D and s retamed in nosition by spring clip S (x·^. 3) engageu within annular groove 40 (Fig. W m the iron ^P°S^to K. 4, sufficient clearance exists between spoolheads A and 8 and the horizontal . portion of bar B, to prevent distortion oi such . bar by a crookedly mounted electromagnet bear£ upwardly against -the front edge thereof Moreover, it enables the coil to be readily removed and replaced. Bar B has sufficient -thickness and consequent rigidity, that it does not require the siwDort of front spoolheadsδ·

As shown in Figs. 1, 3, and-4, each -armature D is arranged to pivot on the upper front edge of bar B, and is -retained pivotally in position by

Upon energization of any of the electromagnets Crthe associated armature-D turns about its axis to bring its lower attracted portion 22 into contact with the domed end of core 4 which provides an adjustable front stop for the armature. Turning the core ί in one direction advances it toward the armature, causing the armature to engage u sooner when being attracted. Turning the core in the opposite direction retracts it, causing tne armature to travel -further before it strikes it. i The rotation of ‘such-armature D raises its actuating portion 21, whereby associated control studs 40, -engaged at their ‘base by sockets 20 thereof, axe pushed upwardly to actuate associated eling blades of the overlying switch assembly E.

Upon-deenergization of the electromagnet, _the downward tension of the associated traveling bladesnf:.assembly E.serve to return the armature to its normal position. As shown m Figs. 3 and- , the normal .or. -backstop -position of the armature is.regulated by the setting of screw 2 6. Turning screw 2 6 -in one -direction stops. armature -D at an earlier point in its return .movement. Turning the screw in the opposite direction permits a more extended return movement of the armature. Locknut 27 when tightened locks screw 28 m a desired-position.

As shown in Figs. 1, 3, and 4, each of the armatures is held in its position on bar B by member 24. Member -24 is provided with arms 28 prefer40

e.

2,665,362

S) ^(fi.^{xed bIade 61 and} Raveling blade ing’blade ₆l^m ThTtwiaM c i* sss-ssisii E=?S£g =sts=-gss wiring convenience. ^F1§· ⁵’ ^for

The traveling blades (57, 59 qnri «, normally closed contacts in column 31 _arp XX p ~SrR' thSwmS^o _t^dh°™^rdlyUCt° ^dns™ⁿC after op Jatiom their normally open position stand⁸the^ress^iO etXdTaS 1° respective travelin* blades and m-»^thn^m_P^{by their}construction with thl I l^{d ais aI1 of} similar “’xSSFr blades 55° and 5? ⁱⁿ*^eT^{diate Positiop} beiore-break and break-make) is also thei we' b?r 67^S (Χ^0Πω o?^eth_P^{by affiXiDS a Spacing mem}-..,-.+. · . the required thickness nf ΐ·ΐια i amed portion of the upper traveling blade 57 one^X’lSXETX:^ T ^{normally requh}'ed, as will be sSse , . . , . ^1Sb· ^{4 an}d 6 show spacing niat? 5a tert srts^Uto^ds_e^b^^VS™^^{e break and} make conΐΕΐ t° ^sePaiai,e their traveling blades G?

and 63 to avoid spacing their actuating1X2 Th^ f°^ntr°^I studs too close together. Th_t. traveling blades of the eontn-&gt;t co+ _f^U2 ^lespective fixed contacts. Such free length contacts and^ ^normaI1y Positions its ontacts and the corresponding on«s of the ™ δ?ΚΚ!!ϊ “ “ ^so^e’^ha‘ X ttx .,. socuied iear end portions. While ouch flexibility is necessary for the travelinoblades’ ba ^{iS e}~^uaIly necessary that the fixed biases have sufficient rigidity to withstand the e““S ΪΧΤτΑ™¹’» *·

.. J^be i^{equired rigidit}y of the fixed blades is provided by using blades which are of twice the Ij 02ⁿ53^S’toch)^he_an¹J^Vh^{eIinS blades} ApproximateM«P. Hg. 5 show, ing 2ΪT?m’n °^{nly thS contact bear}™.'O Χΐ„ ESTlXfX‘·&gt;ί smSo hS »·,** » T« K« a» r ?κ» ^th&gt; xs^; ly «Xi'S* 42½ if* ·» ** !»«»»&gt; « the EmS,· ‘tap “°^nB™ tte‘t,X7V^r”S^{,y T}*^to?^{ea f}»™ »&lt; taloned doinXb X IraeeSS”? ^aMSS ‘&gt;” =X« Εΐ,ϊ ,^e

Kit'S “aSsTb™ head portion (Fia-s 5 tri V ^{haS a deep}S5i⁰^^ntat^S’ ^af™d set wS^Xlato ΕβοϊΧ“ °'a5^e ““I £ E?t «“ retained rear end nf «ⁿ*^{b the exce}Ption of their

ΧΤϊΧ tx¹? -X'.sSS.X ee shown TA “»T ‘ S«Is used, the assembly ^Jjacent to ^ee_aehⁿf^Ue^°^rti0n” ^ofto balance the assemblv h Raveling blade, that (free) portion of thL ^{7 c}°^mpensathig for

XT”?· ™ J;

“° or each or the XVadSTSTXeXS

CO

6a electrical contact upon the engagement^ rf tte respective fixed and traveling blades. Thefieignr of the contact points: carried by .^ /contact Wades is preferably so related to the thickness of the insulators :45 that the desired stroke ctear- ; ance exists between open contacts when the nxea contact blades are straight. This.^tioneasta when the contact-point height is .004 less; tnan half the thickness of the insulators, or app o

Structural rigidity for tlm switch ® and particularly of the fixed blades thereof is provided by the previously-described ^lampmg means. This willbe described more fully atjhis point, for it concerns an important feature ox the invention. As disclosed, the switch assembly is independently assembled from the remaining apparatus and includes the two columns, 30 and 3i of Fig. 5, of contact blades arranged in sets. The upper clamping plate 32 of the assembly, as shown in Fig. 5, has a square rear portion and a narrow¹ forwardly-extending “tongue-like” portion which extends forwardly for the. greater part of the assembly length. Base plate 33 is somewhat similar in shape and is partially shown in

The desired rigidity of - the assembly (wherein two columns of contact-sets are included within one structure) is provided by clamping* one end of all the parts, including insulators 45 which are common to the two columns and which, have the general /configuration of plate 32, between the widened end portions of plates c2 and 33, and by including the tongue portions of the insulators 45 and the greater portion of-the fixed blades within the confines of the clamping structure. Bv this arrangement, a forward anchoring pom is provided for the fixed blades to keep such blades relatively rigid and level throughout which is particularly advantageous where a common actuating means is used for both columns of the assembly, . ,

Figs. 10 and 10A show one of the insulators 45 which are common to the two columns 30 and 31 and which are used to insulate and align the contact blades thereof. Insulators 45 insulate the parts from each other and the rest of the structure, and additionally retain toe contact blades arid the spacing members 66 (Fig 8) in proper assembled alignment. Insulators 45 have raised annular -portions 4G and raised cylindrical portions 47 which /are formed thereon by a semi-perforating operation, which leaves similar depressions on the underneath.side thereof.,

Tigs. T arid ‘8 show respectively the manner in which the annular, portions 46 of any insulator 45 -are Inserted in openings 49 in the retained portions of the fixed and traveling blades to hold such blades in assembled alignment. Fig. 7 shows the manner in which the raised cylindrical portions 47 of any insulator 45 serve as inner-stop positions for fixed blades associated therewith. Such stop positions prevent the fixed blades of columns 30 and '31 from coming into contact with each other and with the forward clamping screw 34. Fig. 8 shows the manner in which the same cylindrical portions 47, of an insulator 45 used adjacently to a traveling blade, are inserted within provided openings in the spacing -members 66 to hold such members 66 in alignment. The aforementioned depressed portions ^;on the/underside of insulators,45 permit a nesting &lt;of toe /insulators arid their 'respective parts to retain such parts in alignment in clamped assembly.

2,’666jS5S

-. A control stud 40 is provided for each column 38 -and =31, as shown for column 3i in Fig. 4, for the simultaneous actuation of the traveling blades of the -contact sets comprising such columns. Each stud is engaged at its base within the associated one of the pair of sockets 20 in the lifting portion 2Lof armature D and passes through/slots 4 i (Figs. 7 to 9) in the traveling blades of the respective column and to the outside of the fixed blades thereof. Each stud has bracket-like ledge portions which engage the traveling blades of its respective column for their actuation when such stud is lifted in response to armature action. The upper central portion of each stud is engaged; as shown in Fig. 4,, in slot 42 of return spring 52 (Figs. 5 and 7) which positions the stud, arid aided by the tension of the -associated traveling blades returns the stud and its armature to normal position upon deenergization of the associated electromagnet.

In the. contact-blade construction herein disclosed (traveling and fixed blades being respectively of a thickness of .0126 and .0253 inch), and where the effective control stud location is - about 1.75 inches from the support line and about 5 of an inch from-the contact points, it has been discovered that satisfactory contact pressure (on the order of thirty-five grams per traveling blad.e for the disclosed twin-contact arrangement) is built up by an over-travel of the stud-engaged intermediate portion of -a traveling blade (either upon operation of the relay or upon restoration thereof) on the order of .006 of an inch.

Observation of the amount of over-travel (travel after the contact points engage) is a reliable indication of the amount of contact pressure. This feature avoids-the necessity in certain other types of -contact blade -construction, of applying a tension gauge to the traveling mem40 bers. .,

In order to fulfill the objective previously stated,-tn provide relay structure capable of being mounted in^; rows -along a common magnetic return: member, where the limited space allotted to each makes the assembly and;adjustment of the ^J widely varying contact sets of the various relays extremely difficult, separate and pre-adjusted assemblies of various combinations of contact sets are provided which are readily mounted as a preadjusted unit alohg-such member.

It has been determined that the four illustrated types of contact sets (make-before-break, breakrriake, break, and make) can be combined into over a thousand combinations, which will meet all normal switchboard requirements.

It is contemplated that the desired combinations of contact sets forming switch assemblies will be produced in lots in the manner previously described for -the armatures, which will promote efficiency in the assemby and-facility in the preadjustment thereof.

After a desired combination of contact sets (the illustrated contact sets comprising columns 30 and 3i of -Figs. 5 to 8 for example) are clamped in assembly, such assembly is adjusted to certain operating standards.

A3. Pre-adjusting the switch assembly E

The steps required to pre-adjust a separate 70 switch assembly E, such as the one illustrated in Figs. 5 to. 8, will now be described,.

The first step is to visually inspect the assembly to be adjusted to determine that all the parts are straight and in alignment. Any parts which are 75 malformed or misaligned are manually straight30

2,665,352 oued. It is contemplated that accurate preformng oi the parts will make this inspection a relatively simple one.

tv3^{he s}®^copd step is to secure the assembly (with the control studs in position) to a special jig whose electrical or mechanical action, preferably the latter, controllably raises and lowers the ?^{e asssmbly in} a manner which imulates. actual armature action, and which permits aesired fine adjustments of the contact sets comprising the two columns of such assem_th J^h®,^{third 8ί}θΡ ^{is t0} adjust the contact sets of tion whfidi^bH ^t0/^{tn operafced} engagement position which closely approximates the fully operwh^T ^{SuCh an epga}^.ent position is one ' which requires only the further travel ( 006 inch over-travel) of the intermediate stud engaged comp°fi ^{travellng Wades of} the sets to become fully operated.

⁸ J/^{d hGre}’^{and in} the normal position adjustS?t?^faCI™^{ate adjustment} of the contact sets of the assembly without regard to contact presture J?¹? ^{1S r}®^{gulated by} the correlating armature adjustment to be described later. ., re^f°^reS&lt;?^ing.adjustment is made’by operat- “ studJ /0 nfth⁰» simultaneously raise the control studs 40 of the two columns of contact sets until b e make contacts of the make and break-make contact sets of the two columns initially make 3 engagement. An inspection will be made to determine if all such contact sets are engaging simultaneously, and any such sets that apS to be engaging prematurely or late, with respect to the majority of the others, arc adjusted for conformance thereto by bending the exposed fiont portion of the upper fixed blades 64 or 60 hereof upwardly or downwardly as required fiist ίΓηιΓί'ΓΤθ?’ ^being_F^{the more} critical, is made t ? ^{aS a} reference point for succeedadjustments.

ihe fourth step is to adjust the normal ensemb?^entTh°^Slt·⁰¹¹ °^{f the contact se}ts of the assembly This is accomplished by lowering the ®°£^{tr01 Studs a} Predetermined amount from the ^{ence p}°^lnt&gt; where the break contacts of the break and break-make sets should initially enau^t’f;,»1,^Aga/ ^V1Sual hispection determines if ail such contacts are simultaneously engaging at do so by bending the lower fixed blades Si or 58 ^{r down}wardly as required. It should be noted that it is satisfactory if the sets engage slightly above or below that predetermined point on the downward stud travel for such point of engagement is not critical.

The fifth step is to adjust the make-beforebre^ak contact sets. This is readily accomplished Strfto^nTtb Λ ^{by bending} the exposed front portion of the lower fixed blade 55 upwardly or downwardly as required. Bending blade 55 Upwardly, with upper traveling blade 57 followtbe’re?^CreaS!® ?^{he gap betw}een the contacts of the intermediate traveling blade 56 and the upper traveling blade 57. Bending blade 55 downwardly decreases the gap. The normal position of adjustment is where the contacts of the three blades, 55, 56, and 57, are in electrical connection at an intermediate point of stud travel with respect to the reference point and the poinTwhere sell rew^i^C0?^aCtS °^{f the break and br}e^ak-make sets initially disengage. Such intermediate position may be determined by a gauging operation with respect to the reference point ^operatlon

The switch assembly E having been assembled

The engagement position 20 are adjusted for 35 and preadjusted to certain operating patterns it is ready ior its final assembly along a common angle bar E, which as aforesaid serves as a common magnetic return member and support for tiie rows of relays mounted thereon. Figs. 4 to 6 show the two mounting screws 35 which freely pass through openings in the assembly and which are threaded into openings 36 (Fig. 1) in bar B to secure the assembly thereto.

A4. Final assembly steps

The final assembly of rows of relays along a common angle bar B comprises four stops which asreinb’ire³¹^ ^and ®^fflciently Performed by the assembreis in accordance with simple assembly sheets which may be provided. ^y step 1.—CORES

As shown in Figs. 1 and 2, bar B first fitted tiom^maTb^{qilC COreS 4 at the rea}-^uired relay locations. This is accomplished by threading the rear portions of the cores, in the manner preim°n^S1fb^def^Crib+^ed’ ^int° ^{the rear flange of bar B}unt.il the front domed end of the cores directlv underlies the front edge of bar B which approxins thP??b^finaH ^{position of the core}s. A locknut L +b»T ^l'^h/^{aded on each} core, but not tightened tnh ^{e froptstop} Position of the armatures is yet to be adjusted. ^J

STEP 2,—COILS

Each of the assembled cores is fitted with an electromagnetic coil 5 of the desired charactereaS’coil⁵ 5°ilⁿ i^{n Pig}- ⁴‘ ^{AS previously} described, from th» f ^ls?^{llppea over} its associated core 4 ?rSg Ληo^{S retained in} Position by a spring chp 9 (Fig. 3) engaged within annular fore^{Ve i0 (Fig- 4A&gt; the fr}°^nt P°^rti°ⁿ of the

STEP 3.—ARMATURES ^{F g}®· ^{1 and 3 show} the manner in which each th» d«f^atJ°^{n 1S fltted with an arm}ature D having the desired residual characteristic. Each armabarBbvan°n^eSaif’ ^{iS r}®^{tained in} Position on re , hl Jarmature retainer 24 which is secured ro such bar by a screw 25.

STEP 4,—SWITCH ASSEMBLIES

Each relay location is fitted with a pre-aswWcifn^^ ^P/’^adjusted switch assembly E, ^blch includes the contact sets adapted to meet tne requirements of that particular relay. The on blr iS ^{installed in} Position ^{ba B and ale sl}mply secured, as aforesaid by ? ⁰ ™^untmg /^{reWS 35}· ^{The swi}tch assemblies he flatly upon bar B with the protruding ends of clamping screws 34 thereof being received in pro olearance openings 37 in Lr B The eonto ia^h rei_a°;°^{ne f}°^{r eaCh C01umn} °^{f contact} sets m each relay, are now inserted into the position shown in Fig. 4. _The stud is inserted from the top Of Lhe assembly within slots 4i (Figs 5 to R) un^ittT¹^ ^bladeS °^{f the} ^eSe columi base engages its respective slot 20 in armature portion 21. The return spring 52 is upraised to permit such insertion. After the stud is so mserted, it is moved forwardly until its ledge portions engage their respective traveling blades ροΐΐ?οη^Ρ°^ητ£ ®^pring,^{52 is} burned to its normal position. The normal position of the snring 52 is where the top central portion of the stud 40 is held within slot 42 of such spring 52.

A5. Final adjustment steps ?^{e r}S^{ays are finally} assembled along the common bar B, only two simple armature adjust10

2,665)352:

' 12 posed sets of blades. each-, including· a flexible travelling,blade and a relatively fixed blade appearing in adjacent layers and arranged to engage and .disengage each other , at their forward end incidental to flexure of the travelling blade, each blade being clamped between the respective rear portions of adjacent laminations, the. forward portion, of each: travelling, blade, being, un-. clamped and extending freely alongside of .the, tongue portion of, the laminations, a portion of each fixed blade being clamped between the respective tongue portions of adjacent laminations substantially throughout the length of such tongue portions.

2. In a contact-blade switch assembly as set forth in claim 1&gt; each travelling-blade layer .including a third member comprising a spacer blade lying , between, the tongue ..portions of .the^adja-. cent laminations and having the thickness of the ..travelling blades, whereby parallelism .is maintained between the clamped laminations in a structure having. travelling blades of a relatively simple outline...

3. In a contact-blade, switch: assembly, two opposed columns, of superposed, contact-making blades and-structure for clamping them in. a. unitary· assembly, said clamping structure including similar superposed . insulating _ laminations with- the.,blades .clamped between them in. suc। ceeding,layers, each layer including a separate blade of. each· stackup,. the two blades of a layer lying, side-by-side,out of contact, with: each other, each·;lamination, having a .relatively wide. gen-, erally rectangular rear portion succeeded by a relatively narrow, forwardly extending tongue portion,, each column including ,superposed sets of blades each including a flexible travelling blade and. a relatively, fixed blade. appearing in adjacent ; layers. and arranged to engage and disengage, each; other .at ..their forward, end incidental to flexure of the travelling blade,.each:blade.being, clamped between .the.respective rear portions of adjacent laminations, the. forward, portion of each travelling, blade/being unclamped and extending freely alongside of the tongue ..portion of the laminations,, each fixed blade being clamped between the.respective.tongue portions of adjacent laminations . substantially throughout the length of such tongue portions, each lamination having am opening through its rear portion, and an opening through its tongue portion, said clamping structure further· including overlying and. underlying clamp plates, respective clamp members,passing through the said, openings out of. engagement with the. blades, and engaging eac clamp plate to damp the said parts of. the clamping structure, rigidly: together.

4. In a contact-blade switch assembly as set forth in- claim 3, each-lamination carrying a nar• row-raised locating member on one surface of the tongue portion and located along the longitudinal .centre, line thereof, the.raised member of the concerned lamination serving at any layer of fixed blades to maintain, the .adjacent .edges of the .fixed, blades out of contact with each other, each layer of travelling, blades including a third, member comprising a spacer blade lying between, the tongue portions of the concerned adjacent laminations and having the Thickness of the travelling blades,, each said spacer blade having,an opening, receiving the said raised member of :the concerned lamination, and having,,a further opening registering, with the said opening through, the tongue portion of the lamina- inents are necessary for each relay to regulate its armature/ travel ler effective cooperation with, the pre-setting of the contact sets of its associated switch assembly E. The first adjustment, is to set the frontstop position of. the armature travel and the second is to set the backstop position. As aforesaid, the frontstop (operated) position is set by the longitudinal positioning , of . the associated core 4 and the,backstop (normal): pqsition is set by. the adjustment screw 26 carried by . the associated retainer 24. .

The frontstop position- of the armature is adjusted to conform to the operated engagement position of the-applied pre-adjusted switch assembly E. This is accomplished by inserting a thickness gauge between armature portion 22 Tor residual plate 23 if used) and the domed end.of core 4. The armatm'e is then operated until tne previously-described operated engagement position (where the,make contacts of the make and break-make sets initially,, engage) of the assembly obtains and the core 4 is adjusted, in the manner previously described, to form a frontstop, position to stop the forward travel of the armature at this point. The thickmess gauge used is of a thickness, that when removed, provides the desired amount of, overtravel for the armature and the associated control studs to provide the desired contact pressure of the make contacts of the associated switch assembly E. .

The backstop position of, the armature. is .adjusted to conform to the normal (unoperated) position of the. switch assembly E. This is accomplished; with; backstop .adjustment screws 26 loosened, by using the frontstop position of the armature as, a reference point and. inserting a thickness gauge between the domed, end of the core 4 and the armature in the manner of the previous adjustment.. The backstop adjustment screw is then tightened and locked in position by locknut 27 to stop the return travel of the armature at this point. The thickness gauge used thus, regulates the armature travel to,a desired amount and determines the normal (unoperated) position of the relay. Such normal position is one where the break contacts of all-the contacts sets of the switch assembly are in engagement with sufficient contact pressure to,insure their reliable electrical connection. The thickness gau^e used is ,of such, a thickness that it , proy.ides .sufficient overtrayel (.006 inch) for the/armature to build up the. satisfactory contact pressure for the break contacts and also provides for a slight, additional armature return travel to provide a margin of, safety whicn is desirable in setting .the .armature backstop position which is not critical after a certain amount of such travel is allowed. The^mqunt of armature travel which permits the break contacts oi the contact sets to properly engage (normal relay position) is.sufficient to, cause the, make .contacts ₆0 of the contact sets to properly disengage.