US2324730A - Delay action mechanism for snap switches - Google Patents

Description

July 20, 1943. E. l.. SHARP 2,324,730

DELAY ACTION MECHANISM FOR SNAP SWITCHES -Fi1ed Oct. 28, 1941 2 Sheets-Sheet l INVENTR..

July 20, 1943. v E, L. SHARP DELAY ACTION MECHANISM FOR SNAP SWITCHES Filed Oct. 28, 1941 2 Sheets-Sheet 2 7W/N6 L. SHARP,

1N VENTOR.

A WOR/V5 Y.

Patented July 20, 1943 DELAY ACTION MEoHANrsM Foa SNAP SWITCHES Ewing L. Sharp, Hollywood, Calif., assigner to Victory Switch C0., Hollywood, Calif.

Application October 28, 1941, Serial No. 416,838

` (C1. 2cm-34) 13 Claims.

The present invention relates to improvements in electrical switches and more particularly to snap switches having an optional delay action mechanism which, upon the completion of the delay function automatically resto-res the switch to a snap action movement.

This invention further relates to certain improvements in both the snap and delay action mechanism set forth in my copending application entitled Delayed action mechanism for snap v switches, Ser. No. 312,011, filed January 2, 1940,

which matured into Patent #2,261,189, November 4, 194i, the present applicationbeing a continuation in part of said earlier application.

Among the more important objects of the invention are: to provide improved circuit opening and closing means for the switch; to provide improved mounting means for the circuit opening and closing means; to provide means for yieldably acting upon certain movable means to make the delay action feature of the switch mechanism more positive.

Speaking more specifically, further important objects are: to provide improved means for making the piston stem mechanism more sturdy and leak prooi; to improve upon the cradle mechanism and dashpot operating mechanism in such a manner that their assembling is facilitated and their parts are simplified so as to create a more positive, inexpensive and dependable construction; to improve upon the brush breaker whereby, whether itis in the open or closed position,l it will act as its own spark gsnuier, because it shields one contact from the other at all times.

With the foregoing and other objects in View, theinvention resides'in the novel arrangement and combination of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed may be made within the scope of that which is claimed, without departing from the spirit of the invention.v

Referring to theY drawings wherein is shown a preferred embodiment of the invention together with an alternate embodiment of one of the switch parts,

Fig. l is vertical mid section showing the switch on er in circuit closing position, the delay action mechanism having remained passive during the conventional manual snap action closing movement of the switch lever. In the tu... the broken line indication or" the switch lever indicates a position thereof. resulting from another conventional manual snap action movement.

Fig. 2 is a view taken on the plane indicated by the line 2 2 of Fig. 1, a side portion of the switch lever being broken away.

Fig. 3 is a vertical section taken on line 3-3 of Fig. 2.

Fig. 4 is a transverse section taken on line 4-4 or Fig, 2 with certain interior parts omitted.

Fig. 5 is a fragmentary transverse section taken on line 5`-5 of Fig. 2 with certain interior parts removed.

Fig. 6 is a fragmentary vertical section taken on line 6 6 of 3, the dashpot cylinder being omitted.

,'7 is a fragmentary perspective viw on a larger scale of some of the parts comprising the delay action mechanism which controls the delayed action ci the switch.

Fig. 8 is a perspective View on a larger scale of the circuit maker and breaker dissociated from the cradle which actuates the same.

Fig. 9 is a plan view showing the cradle, circuit makerand breaker and piston stem operatively related, and,

Fig. 10 is aperspective view showing per se an alternate embodiment of the breaker and brush shown in Fig. 8.

Referring in detail to the drawings, therein is shown an open faced, opened bottom switch casing l constructed from Bakelite or other suitable insulating material and provided with a top wall 2, side walls l and a back wall 5. A cross wall 5, havinga horizontally directed flange 1 and a vertically directed depending ange 8, bridges the gap between the side walls 3 and 4 at their lower iront ends. The vertical outer face of the ilange 3 lies in the same plane as the iront edges of the top wall 2 and the side walls 3 and 4, and the horizontal top face of the flange 'l lies ina plane iiush with the bottom edge of the back wall 5.

In the back wall 5 silghtly above its lower edge Vis formed a transversely extending channel 9 paralleling the walls lower edge to form a seat for the ange i5 of the dashpot Il. Said back wall, on aline with the face forming the top wall of rthe channel 9, is thickened to provide a cam shaped swell l2 the function of which will be explained later.

The dashpot Il has its iront face thickened at i3 and provided with a protruding lip I4 to f form a ledge engageable on its underside by a set screw l5 which extends through the face strap l5@ and with a screw threaded relation through with the inrnost face of the wall 3 i ,-Into the acute anglesof the trapezoidal groove the aforesaid ange 3 to maintain a rigid support of the dashpot against the lower edges of the walls, there being a clearance space between i the videfor the upswingin.g of the dashpot into position when the same is gyrated about said channel S as axis. Y

The dashpot il further comprises a'cylinder p it and rear face of the flange 8 to pro- E having its upper end open and bottom end closed.

is screwed a valve in the form of a screw i? and The closed end of the cylinder is prof i vided with an internally threaded bore into which washer it for contro-lling the influx and efflux f of airto and from the cylinder. Y

A piston i9 operates in the cylinder i saidr .piston being provided with an operating stein 2t. In Fig. 7 it will be seen the piston consists of a cupshaped, flexible gasket washer 2i which ed from a at metal sheet and having a cutout through its mid section, said cutout having an arclike*curvature` 25 forming one of itsV boundaries, and there is gap 215 in the side of the stern which is opposite said curvature. Ineth'e'v front'side of theV upper end portion oi said -cutout is an oiset recess or seat El, theV function of which, as well as that of the arclike Vcurvature v2:3 2G will be explained flater.Y l Y Wall` ofthe casing, asjshown in Fig Gf, is proandthe gap vided with a longitudinally directed guideway c-r tarpezoidal shaped groove 23 extending along the inner face of said wall a shortV distance fromthe back wall 5 as seen in Fig 3 and l'iavingthe-l contracted mouth of the groove orthe shorter paralielside forming the trapezoidal groove flush are sprung the obtusely .directed4 edge flanges and :3.5i of the fulcrurn yoke Si 'which pivotally supports theV two types of breakers 32 and shown in Figs. 8 and 10.

Said yokei is bent upon itself to forni a flange 33 thereby to provide, a pair of Vjaws or arms wherebetween the breaker is pivotailly mounted, there being an aperture or'pivot hole 3ft` inthefbreaker 32 and-an -aperture t-fia in the,A in which seats the boss 35V projecting fro the inner face of the flange 33 vinto the opening formed by said jaws.- Said boss serves the purpose of an axle and veliminates a costly assembling job. .Y .Y

vThebreaker' 327er 'brush carrying member isdesirably made of non-conductor, fibrous material andY carries a brush St, inv theform cfa rivet ,extending therethrough, through which the current iiows when the brush has been` moved from the circuit opening position shown in VphanfV torn lines in Fig. '3 to circuit closing 'positionwith kits contac el and shown in lfigs. 2, 4 andS, In said figures it will be observed the'heads civ the riyethave vbeen.flattened and thatthe con#Y tacts and 33 hai e been inade spoon-bowl shaped in order to facilitate the movement of the brush into circuitrclosing 'relation withits associated contacts. The breaker lbeing a non-coni also maintain their fixed relation.

-sinceY it ductor and constructed so thatthe brush is spaced inwardly from its upper back edge acts as a spark snuferv in either open or closed position, shields Yone contact from the other at all times. Y Y 'Y f Breaker shown in Fig. l0 is constructed alcirT the same lines as breaker 33 except the rush different. the brush Sd is bent around the breaker and The circuit manner to form a somewhat J -shape on each side, the terminalportions 39 andy i6 of the arcuate part of the brush being inturned toward the breaker to provide for their easy entry between theccntacts .Si and Sii. rhis construction provides for soi-.newl'iat greater flexibility, ince after the points and iii enter between the contacts, the body portion of the J-formations may each yieldtoward the breaker; Y rShe saine spark snuit- V:ing ieY ture isv present in this type of breaker as thatalreadydescribed in breaker v32. Y.

As shown in plan in Figa` andin elevation in'Figs. 2 and 3, the sidewalls tand fi of the casingV have -orrned in their upper portion guide-v ways [il and i2 into which the switch terminals i3 and il are extendedrthus bringing their respective contacts Si and 35 into juxtaposition wherein they constitute stationary terminal parts of a Vknife blade switch Wherebetween the brushes 355 and 35a are moved to close an electric cir- The cooperating notches i5 andli'o on one side .of the casing and the cooperating notches lil and i353 on theopposite side of the .casing maintain dependably therplaceinent' ofthe terminals and lili so that the contacts thereof SinceY terminal spans a widerspace than does terminal the terminal ifi is bowed at 9 between the stop pillar' 5d Vand the wall e so as to Wedge therebetween i to kstabilize the deflection which carries the contact 33'. the terminals and is Yshown in Fig. r8,. are screwed the binding screws 53 'and whereto theoircuit wires are joined.

TheA means or actuating the break@ 32,

' whether the yswitch action be oneof` snap or delay comprises the swingable cradle the toggie switch lever 5d and the coil spring,Y 57 operatively relating said cradle and lever.

The external portion of the toggle lever Sill is similar to the conventional leverof'its type eX cept that the trunnions 53 whereby it is pivotallyY vmounted are positioned eccentrically in relation to said lever; Said trunnions rest in seats formed by notches E9 formed in the front edges of the casing side walls 3 and il as shown in Figs. 2

connected to the button iii byineans 'of a stern Said head @it carries` a backward sion Veilhaving anapertured end .portion El' which is attached one end portion of the spiral "spring 5l'. Y

Thevswingable cradle 55 Yshown in Fig. 8 and In the .modified showing Y Into holes 5i andr52, ofv

wennen sited head es which' also in Figs. 2 and 9, is provided with outwardly directed trunnions 68 having bearings within seats formed by the inner ends of the internal grooves 69, see Fig. 3, which are continuations of the notches 58 opening out from-the front edges of the side walls of the casing. At its free end said cradle is provided with a cutaway portion 'I0 extending inwardly part way from one of its side edges and is rounded to produce a striker edge to act upon the breaker whereby to move it from open to closed position and vice versa. When upswung the cradle 55 acts upon the inclined surface 32a: of the breaker and when `downswung said breaker acts upon the upper edge ol the foot portion 32g of the breaker. The relationship of the cradle and breaker is clearly defined in plan in Fig. 9. Said cradle is also provided with an elongated slot il which extends at a right angle in the direction of the axis about which it swings, said slot being located near the remaining free edge portion which extends forwardly of the cutaway portion just described and which. is also rounded to play against the arclike curvature 25 of the piston stem. The limb 'I2 of the piston stem occupies the slot 'li during the upward swing of the cradle and the limb '13 of the piston stern. occupies the slot ll during the downward swing of the cradle.

At a point inwardly spaced from 'the slot 'II the cradle is provided with a seat la for the other end of the spring 51.

The actuating means for producing a retarded circuit opening actiony of the switch, in addition to what cooperating mechanism has already been described, includes a tappet finger 'I5 carried by the hea-d 54 and extending'therefrom at a right angle. Said tappet linger l5 is positioned to act upon a spring resisted slidable engager l5 which, in turn, is positioned to engage the piston stem 2l! to place the latter in position to be acted upon by the spring pressed cradle 55.

The slidable engager 'l has a body portion. l1, (see Fig. 7). carrying a guide or mounting arm '18, which reciprocates in guide groove I9 provided for itin the interior tace of the wall 6, said groove having a contracted mouth 80 (Fig. 2) which keeps arm 'I8 in place. l

In addition to its mountingarin lf3, the eneager lil carries a limb 3l having a laterally deflected push 82 which ispositioned to act upon the forwardly projecting rise 53 of the piston stern 2! to swing the upper end of the latter backwardiy to the lull line position of Fig. lr to cause the bridge 84 ofthe cradle to be brought from the upper seat lila into a superjacent relation to the oiset seat 2l. (see '7 whereby to produce a delayed switch action. A coil spring 8.5 mounted upon a seat 85d having its free end connected to the extension 3io of the limb 8| is utilized to restore the engager to normal position so that when the toggle lever is again actuated, the push 82 will be clear of the path in which the piston stern will upwardly travel and the bridge S4 will occupy the seat 21a.

The upper back portion of the stem 2l! is provided with shoulder 85. see 7, which, as the piston descends, is acted upon by the swell I2 that projects internally from the back wall 5 of the casing to restore the descending piston stern to its forward position, there beingr recessV 81 in the back wall 5 superadjacent the swell I2 'to provide clearance for the shoulder portion y85 incident to its contact with. said swell.

The piston stem Z?! is secured to the piston I9 at a backward inclination to the axis of the piston and the piston I9 is mounted in the cylinder |6`at a forward inclination to the axis of said cylinder whereby to facilitate perinanent seating of the bridge 8d in the odset seat 21 and the forward tilting oi the piston stein when it contacts the swell l2.

A brief resume of the assembling ci the switch and its operation will now be se iorth.

The Abreaker 32 is first installed by projecting it inwardly into the casing as shown Fig. 6 by compressing the wings 29 and 3i] of its mounting yoke 3! into the acute angle recesses into the position shown 3. The tei linals 47 and le are next mounted in their respective grooves thus bringing the contacts 3l and Si. into juxtaposition as hown in ll. The piston and dashpot assembly is next swung 4"itc position by rst positioning the Flange in the channel 9 and apply-ing theV The cradle is next --st .lied by projecting it forwardly into the casing until its trunnions S8 are seated as shown in Fig. As this operation is being performed the bridge is extended through the 25 in the piston stem and the slot El is caused to engage the limb 'I3 of the piston stem. The engager 'l5 with spring 35 is next installed in the groove FS with one end of the spring engaging its seat 85d. The toggle assembly including the spring 57, spring hanger 5S and button assembly E!) is then .istalled with the tr1 =.nnion s 53 or" the lever occupying the seats 5S, and the free end of the spring mounted upon the seat 14 or the cradle. Finally the remaining well kno-wn conventional parts the assembly is conipleted.

The switch normally is in snap action position, and when manually converted into delay will, upon completion of the delay function, be automatically converted back into a position for action movement. This cycle of operation will now be set forth in proper sequence.

In the full line position of the toggle lever in Fig. 1 the switch is in the on position. To move it to dotted line position opens the switch. Moving the toggle lever from one stated position to the other may be carried on ad infinitum with a snap Vaction of the switch always resulting. This is accomplished by the striker shoulder '50 of the cradle contacting the breaker 32 under the compressive force of the spring 5l. During such movements of the cradle the delay action mechanism remains passive. since the bridge 84 of the cradle moves freely up and down in the cutout in the piston stem, and the slot TI adjacent to the bridge permits, free passage of the limbs 12 and 73 therethrough.

If it is desired to produce a delay action in the circuit opening of the switch the button is pushed inwardly incident to actuating the movement of the toggle lever from ti e full line to dotted line position. Such movement of the button causes the tappet 'l5 to act upon the eneager 'lll tofniove the push ringer 'l5 to act upon the engager to move push ringer against the part 83 or the piston thereby to unseat the bridge 84 in the seatZ'fa and move it forwardly into the offset seat 2l. -Such push action having been opposed by the spring The spring 5'! now being placed in a state of compression causes the bridge to bear upon its seat and move the piston thereby unseating the bridge 8f3 from the seat 2l therebyplacing the delay action mechanism in a passive condition andautomatically restoring the snap action Vmovement of the switch.. As sooneas the manual pressure upon the button'is ceased the spring 85 restores the engager to normal position which position clears the push arm 82 of `the path of upward travel of the piston stem. The relationship of the screwi l and washer i6 may be varied to obtain varied periods of Vouter lface of said piston head, said extension projecting through said piston head and being angularly deflected upon the inner face of theV latter thereby clamping said gasket between said disks, the metal strip which forms said stem have ing through it along the greater vportion of its length, a slot, said slot having an offset portion forming a seat, and a spring pressed part comprising a cradle'includinga bridge which acts at times againstsaid seat to move said piston against vthe opposition of the fluid in the dashpot, manually operable means to swing said piston stemto a position wherein the bridge of said cradle is in an engaging relation to said seat, means A,to automatically swing said stem to its original snap action position at the completion of each movement of theV piston into the dashpot,

andV circuit closing'Y and opening;k means actuated by said cradle.

having a cut-out providing ingress to said slot,

the bridge of said spring pressed apart being in sertable through said` cut-out.

having through it a longitudinal slot, thereV being 40 2. The subject matter of claim 1 and, said stem ak cut-out leading.' into one side of said slot in a.

spaced relation to the end thereof which is farthe est from thepiston, thatV end portion of the slotl having an extension directed toward the same large to admit the parl-,of the piston stem between its said seat and cut-out means to manual-` l swing said stem to a ,position wherein said bridge is in an operative relation to said seat, camV means carried by said casing to engage said stern and `restore it to its originalposition, a springoperatively related to said cradle to swing it against saidfseatin opposition to said dashpot,

v the end'thereof-which piston stem swing of said stem which is nearest to the piston head, said spring giving to said cradle a snap action which causes its slotted portion tocross said cutout and pass astrideV the material at the opposite side thereof. Y Y Y 5. In a snap action switch, a casing having a wall: with a groove the mouth of which is contracted, a iulcrum member having opposite edge portions which nt within the deeper portion of said groove and thusmaintainfsaid member in its mounted position, a circuit making and breakingv part fulcruined upon said iulcrurnl member, electrical contacts associated withvsaidV circuit making and breaking part, and means to manu,

ally operate said part. f 6. The subject matter of claim 5 and, said fulcrum member consisting ofia plate having along Veach of opposite edges a iiangasaid anges being deflected away from each other and occupying opposite sidesoi the bottom part of the groove.

7. In a device ci the kind described, a casing, a dashpot structure connected to said casing and including a piston having a stem which is swingable a e in which the airis of the dashpot lies, said stem having a longitudinal slot through it,-said yslot having a lateral recess which forms a seat or shoulder .that is directed away from the head or the piston,a swingable part carrying a bridge to engage said seat at times, a spring positioned toa-ct upon said part to press said inst seat ard thereby Vurge said stem toward the dashpot against the 'opposition of the contents thereof, a slide operable in one irection from its normal posifon to Vengage said to a'position wherein its said sea-t is' engageable by said bridge, a spring positioned to restore said slide to Y normal position, cam means 'carried by the casing to automatically restore piston stern to its original position during the completion oi each downward movement into-the dashpot, and circuit closing and opening Ymeans actuated by said swingable part. n

S. lxiieans for Vretarding the circuit-opening ac,- tion of an electric switch comprising, aV casing, a dashpot cylinder in the lower portionoi said casing, a piston stem` having a head operating in said cylinder, said piston stein having through it a longitudinal slot, there being acntuout leading into one Yside of said in a Vspaced relation to iarthestlirorn said piston, that end portion ot' the slot having an extension directed toward the same vside as said cut-out thereby forming an offset seat which is 'directedV away from the output, a man1 liy operable toggle Vlever mounted in said cas g in iront A of said piston stem, a cradle consisting of a plate therebyfto delay thexsnap action of the switclnY and circuiL closing and opening means actuated bysaid cradle. l`

4. The subject matter of claim 3 and, said cutout being spaced awayy from the end of the `slot having at one end corners each of which is furnished with a trunnion wherebyk said cradle is swingably mounted upon said casing, there being' a longitudinal slot through the opposite end portion of said cradle, said slot being separated from the free end or" the cradle by intact portion which forms a bridge, the slot through said cradle being suiiiciently large to admit the part of the piston stem between its said seat and cutout when said bridge is proiected'through said out-out into sair slot, a spring adjustable by said toggle lever to cause said cradle .to move up or else down, means in part carried by 'said toggle leverY and manually movable in relation thereto to swing piston stem backwardly to a posi tion wherein its aforesaid-odset seat isbrought intoasubjacent relation to said bridge preparatory to the depression of saidrpiston SternbyV said bridge, means carried by the casing to automatically swing said piston stein forwardly thereby releasing said bridge from said seat after it has acted upon the latter to depress the piston, and circuit closing and .opening means actuated by said cradle.

9.1 The subject matter of claim 8 and, yieldable means opposing the manual movement of said means carried in part by said toggle lever.v

circuit openingand closing means comprising a breaker consisting mainly of insulating material, electrical terminals provided with spaced apart contacts between which said breaker moves to open and close an electrical circuit, and a brush carried by said breaker to conduct the current from one Contact to the other in completing the circuit. v

1l. In a snap action electric switch having an auxiliary mechanism for manually converting the snap action into a delayed snap action; an electric circuit contro-lling handle, means for .closing and opening an electric circuit by movement of said circuit controlling handle While said auxiliary mechansm is maintained passive in either direction said handle is moved to open and close said circuit, kspring opposed means operatively related to said auxiliary mechanism, and means carried by said handle and operatively related to said spring opposed means to place said auX- iliary mechanism into position for operation by the movement of said handle in one of its directional movements.

12. The subject matter of claim ll and, yieldableA means operatively related to said handle carried means and the iirst recited means to actuate said auxiliary mechanism.

13. In a snap action switch, a manually controllable mechanism for delaying the snap action, said mechanism including a strip oi rigid material which is movabie both longitudinally and in an edgewise manner, the delay action relating to the longitudinal movement thereof, said strip having through it a longitudinal slot, said strip having a cutout Which aiords lateral ingress to said slot, said slot having an edge portion which forms a shoulder, means having a bridge to engage and press upon said shoulder against the retarding action of said strip, said bridge portion being insertable through said cutout, and circuit closing and opening means actuated by said means.

EWING L. SHARP.

Images