US2739193A - Snap switch - Google Patents

Description

March 20, 1956 H. F. MASON 2,739,193

SNAP SWITCH Filed May 16. 1950 2 Sheets-Sheetl 2 n l r United States Patent() SNAP SWITCH HowardzF. Mason, Los'Angeles, Calif., assigner tuMason ElectricCorporation, Los-Angeles, Calif., a corporation ofCalifomia ApplicatonMay 16, 195i), Serial No'. 162,256 24r Claims. (CL Zilli-6) ThisA invention relates to new and useful improvements in anY electrical switch and deals more particularly with a momentary or self-centering manually operable switch..

Heretofore, momentary switch structure development has not sufficiently advanced to accommodate the man,- datory prerequisites required for certain usage. For instance, in the aircraft industry, particular need is fora momentary switch with apositive feel or snap action to aliirrnativel'y apprise the operator thereof by sense of touch of the completing or interrupting of an electrical circuitfor the predominant noise level in aircraft precludes. use, of the sense of hearing. Snap characteristics havebeenincorporated into switch design by means of current carrying leaf springs or revese-bend. stressbuckling devices intermediate. the. control. toggle or plungerand the contact of the circuit to be` completed. Such design has proved un.- satisfactory and potentially hazardous in aircraft. for no provision ismade for forceably separating the contactsin the event of their fusing together as may be caused. by a remote short circuit in the electrical network.

Further, itis not infrequent that the buckling devices themselvesform a part of the electrical circuit to be'completedwhereintheir functional characteristics are: subject to alteration due to current passing therethrough. Prior attempts to alleviate this danger resulted in addition of une desirable components supplementing the already excessive weight and size of aircraft control devices.

lt is, therefore, an object of this invention to providea momentary electrical switch that is positive.in action,.the closing-and opening of whichV canbe readily perceived by touch.

ltl is another object. of this invention to provide a mo. mentary electrical switch with perceptible snap action characteristics. and' yet provide means to forceably. separateihe contacts in event of failure ofv its self-contained returning means.

Another object is to provider a momentary switch wherein the actuating element is one of then conducting members whereby direct and positive engagement: of. the other contact or contacts may be made.

An incidental object. hereinl is to flexibly mount the receiving contact so that engagement is substantially a pro.- gressivewiping action that both reassures a completed circuit as well as subordinate cleaning of the Contact surfaces;

Another object. is to provide a switch with. such snap action, but relieve the restraining force approximately at the time of the. contact engagement, whereby the energy available to overcome the restraining force is converted to ansincrease in contact pressure.

Another object is toI provide a switch with a means to rapidly separatethe contacts upon interruption of the cir cuit to minimize arcingat the contacts.

Another object is to provide a momentary switch of the above nature that servesa plurality of circuits, the actuatingY elementV being a conductor common tothe said circuits. Further, it isan object to provide such` plural service and yet maintain the unit comparablyl miniature in dimen'- ice sion and' weight as compared to multi-pole switches in present use.

Another object is to provide such a switch with a high current rating that isrelatlvely compact and light weight comparedv to thev function to be performed with an incid'cntal'particular characteristic of the insulationoccupying greater space than the operating elements.

The invention. also has for its objects to provide such means that` are positive in operation, convenient in use, easily installed in working position and easily disconnected therefrom, economical of manufacture, relatively simple, and of'. general superiority and serviceability.

The invention also comprises novel details. of construction and novel combinations and arrangements of parts, whichwill'more fully appear in the courseof thev following description. However, the drawings merely show and the following description merely describes a few embodimentsv of thepresent invention, which are given by-way of illustration` or example only.

ln the drawings, like reference characters designate similar partsin the several views.

Fig. l is aside elevational view of one embodiment of the present invention with the case partially removed show ing the internal working parts thereof Fig. 2 is a` bottom view of the structure shown .inFig. l;

Fig;v 3 is an enlarged fragmentary sectional View, par.- tially cut away, taken along the line 3-3 of Fig. 2;

Fig, 4 is a sectional plan view taken; along= the line 4-4 of- Fig... 3;

Fig, 5 isfasectional plan of Fig. 3;

Fig. 6 is a perspective view of thel spring` element or detentembodied in the present invention;

Fig. 7y is a perspective view of a support plate that-may be` used in conjunction with the spring detent of Fig. 6;

Fig. 8 is a perspective view of the armature included in. the present invention Figs. 9a and 9b are enlarged elevational sections ofthe spring d'etent shown in the normal and in the stressed positions respectively Fig. 10 isv a fragmentary sectional taken along the line 10-10 of Fig. l;

Fig. 1-1 is a side elevational view of another form of a switch embodying the present invention Fig. 12 is a bottom view of the switch shown inl Fig. 11;

Fig. 1`3. isa sectional plan view of the switch taken along: the line` 13-13 of Fig. l1;

Fig. 14 is an enlarged sectional elevational. View of the.` operable components of the switch taken along the line 14'-14 of Fig. 13.;

Fig. l5 is a side elevational sectional view takenV along the line 15-15 of Fig. 14; and

Fig; 16 is a sectional side sectional view of another form ofthe switch embodying the presentk invention.

In the drawings, wherein for the purpose of illustration are shown the preferred embodiments of this invention-7 and first particularly referring to Figs. 1 5, inclusive, rep'- resenting. one embodiment illustrated as a four pole switch, the reference numeral itl indicates the frame of the switch which is preferably fabricated of sheet metal and;having:a base 11 with a center hole 12 therein as seen irnFig;v 5A and having upturned side portions 13, the side portions meeting at their edges as indicated by the numeral'. 14, thus forming a cavity 15 for the frame. The frame'. 10 is shown as substantially a parallelepiped, but it is within contemplation that other forms may be constructed, for example, cylindrical or octagonal.

A key plate 16 as best seen in Figs. 3 and 5 having an outsidev periphery corresponding to the inner wall' surview taken along theline. 5-5

plan view'of the cap faces 18 of the frame 10 is attached tothe base 11 on the` a studs being secured to the base and extending through the key plate' to provide a protruding stem 2lb adjacent each side portion 13. The key plate i6 is provided with a central void extending therethrough and havingv an in-v ternal periphery substantially parallel' to the s`ide' por tions 13. Y t v y.

A guide bar 25 is provided at cach .juncture 14 of adjacent side portions, extending from the key plate'l tothe opening of the cavity l5, and is securedto ea'ch adjacent side portion by spot welding or any adequate attaching means. Such securing efects complete structure rigidity of the frame it! and retains the key plate 16 in position.

Disposed between each adjacent pair of guide bars 25 is a support plate 26 (detailed in Fig. 7) and one or a plurality ofspring detents 27 (detailed in Fig. 6) associated with each plate, which comprise the spring meansfor tbe switch. The spring detents 27 may be used individually or nested together as indicated in the drawings. For purposes of expediency, the function of the plate 26 and detents 27 will be described hereinafter.

Referring to Fig. 7, lthe support plate Z6 has a base portion 28 and upturned opposite ends 29 and'30 substantially parallel to each othery to provide retaining abut ments for the detents Z7. The end 29 is provided with a notch 31 on the outer edge'32 thereof, whereas the end 30`has a circumferential depression 33 on the outer edge 34 thereof.

One or more spring detents 27 may be nested or stacked -on the base portion 28 and within the ends 29 and 30 'of the support plate 26 and the combination slidably inserted between the guide bars 25 (see Fig. 5) to engagement with the key plate 16 whereby the protrudingstern of a stud 19 engages the notch 3l. to retain the base Vportion yof the plate Vin fixed abutment with the inner side wall 18 of the side portion i3. The stern 23 also-'serves to prevent the detent 27 from falling from position. Thus, it is readily seen that the support plate 26 and its ass0- ciated detent 27 are retained in position on three sides.

To complete the securing of the plate 26 and the detent 27, a bracket 39, asbest seen in Figa-l and 4, is attached,

for example, by spot welding to the outer surface of each side portion 13, each bracket being provided with extending fingers 42 that bend over the side portions and into the cavity 15 and rrnly engage the outer edge 34 of the support plate 26 and extend further to retain a detent or detents 27 in position.

The brackets 39 also serve by means of integral straps 4l) to mount electrical contact assemblies i3 to the frame 10. Each assembly 43, as best seen in Fig. 3, comprises an arm or pole 44 made of a llat strip of electrical conductive material and sufficiently flexible and resilient to yield along the at under cantilever stress as hereinafter will be described. At one end of the arm d is a contact butazsaies y located thereon and juxtaposed opposite to the corresponding contact buttons '45 ofV the assemblies 43.

The armature 5th, as detailed in Fig. 8, is essentially a shaft 52 and has a stem 53 that extends through the center hole 12 of the base 11 as best seen in Fig. 3. The armature 50 is limited in vertical movement by means of a screw or stud 54 tapped orrpressed into the stem 53 from the exterior of the frame 10. A lockwasher 55 may be used to prevent the screw 54 from loosening due to external vibration as well as to provide a greater contact area against the base 11. The stem 53 is of such diameter and suicient length to extend substantially through the base 11 so as to permit the armature 50 to be angularly displaced within the cavity without stressing the base 1l.

The actuated end 57 of the armature 50 is provided with an undercut 5S and a dowel or pin hole 59 to accommodate attachment of a knob 56, as seen in Fig. l. Intermediate the ends of the armature 50 is an enlarged portion 6% that may be of any suitable shape to provide an adequate mounting area for the contact buttons 51. The drawing shows this enlarged portion 60 to be substantially cuboid in shape providing mounting spaces or surfaces 61 to which the contacts 51 are rigidly iixed and electrically conductive thereto.

Adjacent the stem 53 is another enlarged portion 63 having faces 64 parallel to faces 61 of the enlarged portion 60. Each surface 64 has a salient stud65 protruding therefrom to engage with its corresponding detent 27 when the armature 5G is angularly moved toward the said detent. The stud 65 is rigidly pressed into each surface 64 and is made of an insulating material and abradable as compared to the detent 27 so that any abrasion or wear will appear at the stud 65 so as to preserve the spring characteristics of the detent. The surfaces 64 are grooved transversely and tangential to the shaft 52 as indicated by the numeral 66 to preclude intereference with the studs '19 when the armature is displaced.

The bottom face 67 of portion 63 is substantially splieroid in form, being in abutment with the base 11 and accommodates the rocking motion of the armature 5l! at the base 11 of the frame 10 so as to maintain continuous 'electrical contact therewith. Referring to Fig. 3, the contact of the armature 50 with the base 11 can be visualized. Electively the armature may be displaced from y tacts are all normally open. However, it is contemplated ton 45, the other end 46 being provided with a holeto receive a connecting wire. A band of electrical insulating material 47 is wrapped about the arm 44 intermediate the ends thereof so that when the assembly 43 is placed in position it will be electrically insulated from the frame 10. The straps 46 that laterally extend from the bracket 39 are bent overito secure the assembly 43 in such a position that the Contact button i5 is disposed above and directly toward the cavity l5 of the frame lil. For purposes of illustration only, four contacts are utilized and are symmetrically disposed aboutl the frame 10 and directed toward the cavity l5. lt is contemplated, however, that the structure may be so arranged to accommodate any plurality of contact buttons symmetrically disposed about the said frame. The associated arm 44of each contact 45 is connected at the hole 46 to the appropriate circuit to be connected or energized.

The above-mentioned plurality of circuits are individually energized from a common source of potential and are initiated by a manually displaceable armature 54B as seen in Fig. l which is partially disposed in the confines of the cavity 15 and having contact buttons Si appropriately that one or more may be normally closed. Manual armature actuation to the phantom position indicated by numeral 68 as seen in Fig. 3, will cause engagement of corresponding contacts 45 and 51 to energize the associated circuits. Release of the armature will result in the associated detent 27 forceably returning the armature 59 to its center normal position.

The electrical aspects ofthe switch are as follows: Thearmature 50 serves as a common terminus for all of the contacts 45. A source of electrical energy may be applied to the armature 5@ through the mediumfof a common terminal 70 that may be attached to any portion of the frame l0, in the drawings being indicated as attached to the outer face of the base 11 as best seen in Fig. v2. Electrical energy is conducted from the base 1i (see Fig. 3) through the surface contact of spheroid face 67 of the armature 50 and thence through the armature to the contacts 51 thereon. Angular displacement of the armature 56 toward any of the contacts 55, being against restraint of the associated detent 27, communicates the appropriate contacts 45 and Si thereby coneramos s .ducting the potential :through the associatedarm 44 and -to Ethe :circuit vto be energized.

.Particularly 'significant during engagement of contacts and 51 is the lprogressive wiping laction thereof as ithe armature moves to its maximum displacement. As hereinabove indicated, the arm 44 is resilient and when contact is made, it will yieldingly Vmove away from the upper portion of the frame 10 under influence Afof 4the armature. The pivotal motion rof the armature, its -radius arm, andthe voutward angle ofthe `arm 44 all coactively interrelate so that from the instant of contact to the maximum displacement ofthe armature, the contacts 45 and 51 will slide or wipe with respect to each other, .the said wipe being effective as to both of said contacts. Thus, if the .engaging surface has oxidized, pitted or become contaminated byforeign elements, the slide action will sub stantially assure completion-of the circuit to be energized. Further, the relative portion of .the contacts will effec- :tively wipe the surface and remove, by abrasion, the deposit of foreign substances that may have 'accumulated thereon.

The hazard of Vfused contacts is minimized by ythe `structure disclosed in .that the contacts .may be forceably separated .by manual pressure of the operator in the event 4that the detent force is insufficient to separate the contacts. Angular displacement fof the knob 56 away from the 'fused .contacts tends to draw the arm 44 along with the armature 50. The internal shearing stress built .up in the Varm 44 coupled with longitudinal .stress 'therein as the contacts tend to wipe is sufficient to separate'the contacts 45 and 51 under usual fused conditions. In addition, when the arm 44 has returned to a position wherein it presses -against the bracket 39 which .is firmly mounted to the frame 10, its motion is further restrained at the upper portion of the frame to practically assure interrupting the circuit.

Hence, there is provided a means to individually energize the four circuits that may be connected to'the arms 44. Although four paths for circuit energization are shown in the drawing, such is not to be deemed a limitation of the disclosure. It is contemplated that the frame structure and associated components may be designed in variation to accommodate aplurality of circuits, more or less than represented herein.

The switch assembly, as above described, is ldisposed within the contines of a hollow case `90 as seen in Fig. l, .the case 'being preferably formed of an insulating material such as bakelite, and the assembly Vbeing retained rin said case by a ller substance 91 such as polyethyl and 'properly heat treated to cause adherence of the lswitch assembly to the case. A cap 92 is rigidly axed -to `the top of the case and is provided with a central opening therethrough defined by coalescent circumferential coves 93, as best shown in Fig. l0, that are adapted to receive the armature 50 when displaced. The coves 93 are ef- -fective to direct as well as limit the motion of the displaced armature, as indicated .in phantom by the numeral 94.

The detent 27 provides a novel means of action of the switch armature and the resultant physically perceptible snap. Fig. 6 shows a perspective of the detent 27 in detail in normal position. Figs. 9a and `9b show an exaggerated cross section of the detent as normal and as flexed respectively, when operatively associated with the support plate 26. As hereinbefore indicated, a .stud 65 is the engaging member with the detent, the force being represented by the arrow 71 as seen in Figs. 9a and 9b The detent 27 ispreferably made of a material such as strip Iberyllium copper which, after fabrication and heat treating, is highly .resilient and fatigue resistant. It is substantially rectangular in plan view with a length approximately twice that of the width, but dimensional variationsare expressly within the scope ofthe disclosure. In bothside elevations ,the detent 27 is convexe-concave or Apositive snap action will occur.

slightly arched. Two symmetrical longitudinal and vcurvilinear slots or voids 74 are die stamped or perforated through the detent to provide an intermediate or center band 75 and two side .bands 76 which terminate at buttress ends 77. The center band 75 is provided with a more pronounced arch than the side bands and protrudes above the side bands as shown in Fig. 9a. Also, the center band 75 is further deformed intermediate its ends by an upwardly coved transverse arch 79. Two convexoconcave reinforcing ribs 81 provide further deformation of the center band 75 and buttress ends 77 being longitudinal of the center band 75 and extending from a point adjacent the transverse arch 79 to and through the buttress .ends 77, thereby forming channels 82 on the under side thereof.

The detent 27 is flexed by means of force applied to the transverse arch 79. Let it be assumed that the detent is placed upon a flat supporting surface and force progressively applied. The said .force tends to flatten the center band 75 causing the ends 77 to first depress into firm contact with the support surface. The force also tends to spread the buttress ends 77 away from each other thereby effectively causing the side bands 76 to come into flat engagement with the support surface. Further, the force tends to transversely flatten the buttress ends 77. When this longitudinal and transverse 'flattening reaches an ultimate point, the center band 75 is under considerable stress, the forces being resolved against the sides of the transverse arch 79 and resulting in a exing thereof to permit the center band to snap through in a direction normal to the surface, the reactive force component operating through the reinforcing ribs 8l to cause the but tress ends to rise from the surface. Simultaneously, the side bands 76 will rise from the surface. The detent is then flexed as seen in Fig. 9b but under internal stress that tends to cause a return to normal position as seen in Fig. 9a.

If the detent 27 is used in conjunction with the support plate 26, which is the preferred application, a more This is primarily due to two salient projections or dimples 84 which are provided in the base portion 28 of the support plate 26. The projections 84 are substantially laterally central of the base portion 28 and adjacent the depending ends 29 and 30 and so positioned to engage the channels 82 of the detent 27. The initial force on the center band 75 tends Vto flatten it, but instead ofthe ends 77 thereof being firmly pressed onto the support surface as hereinbefore indicated, the channels 82 are depressed into firm point contact with the dimples 84. The side bands 75 and buttress ends 7'7 progressively flatten, but the opposing force is now primarily at projections 84. Under these conditions, the snap through of the detent is more pronounced.

The support plate 26 may be provided with a third upwardly convex projection or dimple 85 located symmetrically centermost of the base portion ZS, to engage with the under side of the transverse arch 79. In this manner, any excessive force that may be applied to the detent will not crush the transverse arch.

Peculiarly characteristic of the detent action is the rcstraining force opposing the force applied. For example, but not in limitation, the detent may be so designed .that two and one-half pounds force is necessary to cause a snap through, however, only one-half pound is necessary to maintain the detent iiexed. Effectively, therefore, the restraining force is relieved to such an extent to retain only sufficient force to assure a return of the armature to neutral. The internal stresses in the detent that tend to return it to normal provide only relatively small force against its engaging stud 65 which is physically perceptible at the armature as a accid or spongy condition. Little effort, therefore, is necessary to maintain the contacts closed. Upon'relieving the holding force by the operator, the internal stresses in the detent are relieved and transmitted to the armature asa physically perceptible snap.

i 7 Accordingly, the operator has a definite touch indication when the circuit is closed or opened.

The force necessary to actuate the switch is capable of -variation by using a plurality of detents nested or placed on top of each other. Fig. 3 is representative of such application wherein three detents are shown in cross section for each individual switch element.

The function of the detent in minimizing arcing at the contacts may now be readily understood in that the contacts make and/or break with a considerably greater velocity than they would otherwise in the absence of the detents. The increase in Velocity is effected due to the relieving of the restraining force as the detent snaps through. Conversely, when permitting the circuit to open, the internal stresses in the detent that convert to an active force when snapping back increase the velocity of contact break. The interaction of the detent with the purely physical muscular reaction of the operator affords this velocity increase without the aid of mechanical acceleration devices.

Figs. 11 through 15 show a modified form of the present invention wherein the detent is carried within the confines of the armature itself. This embodiment as shown is representative of a double-pole,.double-throw switch, but application is contemplated to encompass any combination of single or double-throw with any plurality of poles. Referring particularly to Fig. ll, a case 100 and a support plate 101 provide the housing for the switch assembly. Electrical connections are conveniently extended from the bottom of the case for attachment to the circuits to be completed.

An armature 102 is pivotally mounted by studs 103 between -two pivot plates 104 made of electrically conductive material, the plates in turn being attached at their sides to two oppositely disposed contact plates 105 made of insulating material as seen in Fig. 13. The assembly is completed by means of pins 106 that are rigidly affixed to the sides of the pivot plate 104 and extend therethrough and into dowel engagement with the contact plate S. Each contact plate cantilever mounts a pair of arms 107 as seen in Fig. 14. A contact 108 is adapted to the free end of each arm, the opposite end 109 being provided with a hole for wire attachment to the circuit to be completed.

The armature 102 comprises a rectangular frame 112 made of insulating material and is provided with a rectangular opening therethrough to accommodate the support plates 26 and associated detents 27. A pair of conductor straps 113 as seen in Fig. 15 mounted by means of studs 111 to the sides of the frame 112, each strap having two oppositely extending portions 114 at each end thereof, the said portions of which form about and are in hat abutment with the faces of the armature 102. The lower extremity of each conductor strap is Vprovided with a hole to receive the pivot studs 103. TheV portions 114 of the other extremities of the straps 113 serve to mount the contacts 110 in engagement juxtaposition to the contacts 108.

To accommodate a double-throw type switch, two support plates 26 as seen in Fig. 14 are disposed back to back within the frame 112 and one or a plurality of the detents 27 are stacked on each as desired. These components are retained by means of retainer plates 117 of insulating material each having an opening substantially central thereof, the plates being conveniently maintained in position by the overlapping of the portions 114 of the straps 113. Each opening provides access to the detents 27 for engagement with a stud 118, the stud being firmly mounted to and extending from the plate 105.

As the armature is displaced by a control toggle 119,

the stud 11S urges the transverse arch 79 of the detent as hereinabove described with the resulting snap action. Engagement of the contacts 108 and 110 is thereby effected in a similar manner as hereinbefore described.

. It may be desirable to decrease the number of detents in each stack or to increase the normally open span between the contacts to provide additional lost motion prior to contact. To accommodate such variations and prevent the armature from moving freely between the studs 118, a pair of springs 120 may be utilized, as seen in Fig. 14, cach being intermediate the armature 102 and `the plates 105. The springs as shown are of the coil type but it is contemplated that any appropriate yieldable spring element may be used.

The working elements are mounted in position within the confines of the case as seen in Fig. 1l, the electrical connections extending down and through the case for convenient attachment to the associated circuits.

The electrical circuit is completed as follows: Through one of a pair of terminals 121 which is attached to one of the pivot plates 104, from an annular portion 122 of the pivot 103 through its face abutment to the strap 113, through the strap 113 to and through the contacts and 108, and thence through the arm 107 to the arm extremity 109.

It is to be noted that the circuit is completed through the annular portion 122 and the strap 113 which are movable with respect to each other. This engagement, however, is rendered firm and electrically continuous by the expedient of stressing the strap 113 so that the normal tendency of the unsecured lower extreme thereof is to extend away from the side of the armature. When the switch is assembled within the case 100, the plates 104 are located so as to cause the annular portion 122 to normally press against the extended strap 113, thus rendering an effective Vspring loaded pivotal contact. vIn maintaining this firm abutment a means is provided to preclude the passage of foreign material therebetween that otherwise may adversely aicct the action of the pivot joinder.

Figs. ll and l2 show the terminals 121 and the arm extremities 109 extending through the bottom of the case 100, the case being provided with slots to receive the said terminals and arms and thereby retain the component pairs attached thereto in iixed relationship with one another. A pair of screws 123 hold the assembly in position by means of a pair of bosses 124 and in such a manner the dowel type assembly as described is adequately secured. lf necessary, the case 100 may tightly accommodate the switch element to prevent separation of the plates 104 and 105.

The action of the switch components in this embodiment is the same as hereinbefore described including the snap characteristics, the wip-ing of the contacts, and the means to forceably separate the contacts in event of fusing.

Fig. 16 shows a plunger actuated switch utilizing two detents or sets of nested detents 27 and 27a. A case 125 houses the switch components and also slidably mounts a plunger 126 and a compression spring 127. A stem 128 of the plunger is the actuating extremity and engages a contact leaf or arm 129 which is supported at one end by the case 12S, the other end thereof having a contact button 130. Afiixed to the arm 129 is a stud 131 which is in alignment with the axis of the plunger, the stud extending into engagement with one of the sets of nested detents 27. The detents are supported by a retainer plate 26 in the hereinbefore described manner, except -that the plate is provided with overlapping extensions to retain the detents within the confines of the plate. 'The plate 26 is rigidly attached to a second contact leaf or arm 132, one extremity of the arm being attached to the case 125 and the other extremity thereof having a pair of contacts 133. Similarly aixed to the arm 132 is a stud 134 which engages the next adjacent set of nested detents 27a. This set of detents is retained in a similar manner by a retainer plate 26a, the plate being rigidly attached to a conductor arm 135 which is in firm engagement with the case 125. The conductor 135 extends similar to other contact arms and has a ying stud with .respect to the conductor.

contact button .136 at the end thereof. Only ltwo sets .of contacts and associated detents have been shown as representative of a sequential structure. It is contem- .pl'ated that conductor arm 132 may be constructed as a double leaf with insulation therebetween and with a contact 133 on the end of each leaf. In such a structure the center conductor 132 would not be electrically y,common to both adjacent arms and thus it will provide `for individual circuit connections. It is also contemplated that any plurality of contact leads may be placed -in sequence and operate substantially as will hereinafter be described- Of Vparticular .novelty herein is the sequential operation of the contacts. One set of nested detents may contain a determined number of leaf detents whereas the other set may :contain a more or less number. In such a manner, when the plu-nger 126 is depressed, the associated con- ,tacts will .engage in accordance with the restraining force of the detents whereby one set of contacts will close before the other set will close. For example, assume that the detents affixed to the conductor 135 are fewer in number ,than the detents affixed to the contact leaf 132. When the plunger is depressed, the contacts 133 and L136 will first close and as force is progressively applied to the plunger, then the contacts 133 and 130 will close. The appropriate circuits to be energized are selectively attached to the contact arms and conductor arm. The `perceptible snap action and the wiping of the contacts are equally attained in this embodiment.

The same sequential action may be provided with an equal number of detents for each conductor by the expedient of varying 'the location of the detents and engagu For example, in Fig. 16, if the detents 27a and the associated stud ,134 are moved toward the contact extremity of the condoctors 132and 13S, the moment arm is increased. Thus, with .equal characteristics of both sets of detents v27 and 27a, actuation of the plunger 126 will first cause engagement of fthe contacts 130 and 133, and progressive actuation thrQugh the increased moment arm will cause subsequent vengagement of `the contacts 133 and 13 6.

While the invention that has been illustrated vand described is now regarded as the preferred embodiments, the constructions are, of course, subject to modifications without departing from the spirit and scope of the invention. It is, therefore, not desired to restrict the .invention to the particular forms of construction illustrated and described, but to cover all modifications Vthat ymay fall within the scope of the appended claims.

I 4claim as -my invention:

1. ,In Ia multiple-pole electric switch, the combination of: a frame having a base and providing a cavity; an armature disposed within said cavity land universally mounted to and in continuous conductive relation with vsaid base; fa plurality of first contacts conductively mounted to said armature; stationary means providing a plurality of second contacts in paired juxtaposition with said first contacts; a corresponding plurality of yieldable snap means linter-mediate the wall of said cavity and said armature but insulated therefrom to posit-ion said armature centermost of said cavity, each said means having predetermined reactive characteristics; and unitary means connected vvto said armature operative to selectively register 'any pair of said vfirst and second contacts in conductive relation against restraint of its associated snap means- 2. In -a multiple-pole electric switch, the combination of: a frame having a base and providing a cavity; an armature partially disposed within said cavity and universally mounted to said base and .in continuous conductive relation thereto; a plurality of first contacts 4mounted on the outer end of said armature; yieldable snap means disposed within said cavity intermediate the wall thereof and k"sa-id armature to position said latter means substantially centermost of said cavity; a yplurality of :resilient ,conductors mounted to said frame but insulated therefrom; a plurality of second contacts each conductively mounted on said conductors and in paired operative juxtaposition with said first contacts; and unitary means con nected to said armature operative to selectively register any pair of juxtaposed contacts in conductive relation against restraint of said yieldable snap means, said unitary means also being operative to cause displacement of the associated conductor to effect a wiping action between said contacts while in conductive relation.

3. In a multiple-pole electric switch, the combination of: a frame having a base and providing a cavity; a movable armature partially disposed within said cavity and universally mounted in continuous conductive relation to said base; a plurality of first contacts in secured conductive relation to said armature and disposed about the extended end thereof; a corresponding plurality of studs mounted on the armature portion within said cavity and in substantial planar alignment with said first contacts; a plurality of resilient conductors mounted to said frame vbut insulated therefrom each having a second contact in paired operative juxtaposition to each of said first contacts; a plurality of yieldable means intermediate the wall of said cavity and the said armature for operative engagement with said studs; and unitary means connected to vsaid armature operative to selectively register any pair of juxtaposed contacts in conductive relation against restraint of the corresponding yieldable means, said unitary means also being operative to cause displacement of the associated conductor to produce a wiping action between said contacts while in conductive relation.

4. An electric switch according to claim 3 wherein each of said yieldable means provides a predetermined reactive force and includes a snap element to substantially relieve said force prior to engagement of said contacts to cause said contacts to engage with rapid motion.

5. .An electric switch according to claim 3 wherein said studs comprise an Vinsulating material comparably abradable relative to said yieldable means.

6. In an electric switch, the combination of: a frame having 4a base; a movable armature disposed within said frame and universally mounted in continuous conductive relation to said base; a plurality of first contacts mounted on and in conductive relation to said armature and disposed thereabout; a plurality of resilient conductors mounted in normal abutment to said frame but insulated therefrom each having a second contact in paired juxtaposition to one of said first contacts; a corresponding plurality of .yieldable elements intermediate said armature and said frame; and unitary means connected to said armature operative to initially displace said armature against restraint of any of said yieldable elements to selectively register the corresponding pair of juxtaposed contacts in operative engagement, said means also being operative in event of inadvertent adherence of said con- Vtacts toforceably displace said armature and separate said `contacts due to internal stress and by restraint of the associated conductor in abutment with said frame.

7. :In a snap switch, the combination of: a support; movable, first contact-carrying means mounted on said support and providing a first contact; second contactcarry-ing 4.means mounted on said support and providing a second contact engageable by said first contact upon movement of said .first contact-carrying means toward said second contact-carrying means; yieldable, snap-acting, springA means engaging and positioned between and mounted on one of said tirst and second contact-carrying means A for resisting movement of said first contact-carrying means toward said second contact-carrying means witha .predetermined reactive force; and control means connected `to said `first contact-carrying means for moving same toward said second contact-carrying means so as to overcome the .resistance offered by said reactive force provided `bysaid spring means, whereby said spring means yields with a snap action to provide for movement of l1 said first contact into engagement with said second contact with a snap action.

8. A snap switch as defined in claim 7 wherein said spring means is mounted on said second contact-carrying means.

9. A snap switch as defined in claim 7 including another first contact on said first contact-carrying means, another second contact-carrying means mounted on said support and providing another second contact engageable by said other first contact upon movement of said first contact-carrying means toward said other second contact-carrying means, and another spring means corresponding to the one defined in claim 7 and engaging and positioned between and mounted on one of said first l contact-carrying means `and said other second contactcarrying means.

10. A snap switch as defined in claim 9 in which said spring means are mounted on said second contact-carrying means, respectively. A

ll. A snap switch according to claim 9 wherein said spring means are mounted on said first contact-carrying means.

' l2. A snap switch according to claim 7 wherein said spring means is mounted on said first contact-carrying means.

13. A snap switch as defined in claim 12 wherein said spring means comprises leaf-spring detent means.

14. A snap switch as defined in claim 12 wherein said spring means is located inl a cavity in said first contactcarrying means.

l5. A snap switch as defined inv claim 7 including additional spring means for biasing said first and second contact-carrying means apart to separate said first and second contacts in the event of adherence thereof.

16. A snap switch as defined in claim 7 wherein said second contact-carrying means is movably mounted on said support and provides another second contact, said snap switch further including: a third contact-carrying means mounted on said support and providing a third contact engageable by said other second contact upon movement of said second contact-carrying means toward said third contact-carrying means; and another yieldable, snap-acting, spring means engaging andipositioned between and mounted on one of said second and third contact-carrying means for resisting movement of said sec- Yond contact-carrying means toward said third contactcarrying means with a predetermined reactive force, whereby said control means connected to said first contact-carrying means acts on said second contact-carrying means through said spring means between said rst and second contact-carrying means, each of said spring means yielding with a snap action upon application to said control means of an operating force sufiicient to overcome said reactive force provided by such spring means.

17. A snap switch according to claim 16 wherein said control means includes a plunger movably mounted on said support and engaging said first contact-carrying means.

18. A snap switch as defined in claim 16 wherein said reactive forces provided by said spring means differ to provide sequential engagement between said first contact and the first-mentioned second contact and between said other second contact and said third contact.

19. In a multiple-pole electric switch, the combina- ,tion of: a frame providing a cavity; movable means disposed within said cavity and providing `a pluralityY of first contacts; stationary means providing a plurality of second contacts in paired juxtaposition with said first contacts; a corresponding Vplurality of yieldable snap means for co-operation with said movable means to position said latter means centermost of said cavity, each of said snap means including at least one leaf spring'shaped in convexo-concave form in one dimension having stresses therein tending to maintain said spring extending in a v normally stable longitudinal direction and includingperforations therethrough to provide longitudinally thereof two side portions and an intermediate portion; and control means connected to said movable means operative to displace said movable means against the intermediate portion of alsaid spring to selectively register any pair of juxtaposed first and second contacts in conductive re lation with a snap action.

20. In a multiple-pole electric switch, the-combination of: a frame having a base and providing a cavity; a movable armature partially disposed within said cavity and universally mounted in continuous conductive relation to said base; a plurality of first contacts in secured conductive relation to said armature and disposed about the extended end thereof; a corresponding plurality of studs mounted on the armature portion within said cavity and in substantial planar alignment with said first contacts; a plurality of second contacts mounted on'said frame and in paired juxtaposition with said first contacts; a plurality of yieldable snap means intermediate the wall of said cavity and the said armature for operative engagement with said studs, each of said snap means having predetermined reactive characteristics andv including at least one leaf spring shaped in convexo-concave form in one direction having stresses therein tending tol maintain said spring extending in a normally stable longitudinal direction and including perforations therethrough to provide longitudinally thereof two side portions and an intermediate portion; and means engaging said armature to displace said armature to cause one of its studs to press against the intermediate portion of one of said springs whereby the corresponding yieldable means will flex with a snap action to selectively register the cor responding pair of first and second contacts in conductive relation. A

2l. In an electric switch, the combination of: a frame having a base and providing a cavity; a movable armature made of relatively rigid and conductive material partially disposed within said cavity and universally mounted 'in continuous conductive relation to said base; a plurality of first contacts mounted on said armature and disposed about a portion thereof spaced from said base; a plurality of resilient conductors mounted exteriorly of said frame but insulated therefrom each having a second contact in paired juxtaposition to one of said first contacts, each said insulated conductor having a portion thereof normally abutting and restrainable by said frame and relatively tiexible for movement away from said frame; a corresponding plurality of yieldable elements intermediate said armature and said frame for maintaining said armature normally centermost of vsaid cavity, each of said elements being characterized by a length of leaf material shaped in convexo-concave form in one dimension adapted to iiex with a snap action; and unitary means connected to said armature operative to initially displace said armature against restraint of any of said yieldable elements for flexure thereof to selectively register the corresponding pair of juxtaposed contacts in operative engagement with rapid motion, said means being operative to cause displacement of said portion of the associated conductor to produce a wiping action between said last-mentioned contacts.

22. In an electric switch, the combination of: a frame having a base and providing a cavity; a movable armature made of relatively rigid and conductive material partially disposed within said cavity and universally mounted in continuous conductive relation to said base; a plurality of first contacts mounted on said armature and disposed about a portion thereof spaced from said base; a plurality of resilient conductors mounted on and exteriorly of said frame but insulated therefrom each having a second contact in paired juxtaposition to oneof said first contacts, each of said insulated conductorshaving its lower portion rigidly secured to said frame, the upper portion mounting its said second contact normally ex tending in abutment with said frame and upwardly there of; a corresponding plurality of yieldable elements disposed intermediate said armature and said frame for normally urging said armature centermost of said cavity, each of said elements comprising a length of leaf material shaped in conveXo-concave form adapted to yield with a snap action; and means engaging said armature for initially displacing the same against restraint of any of said yieldable elements to selectively register the corresponding pair of juxtaposed contacts in operative engagement with a wiping action, said means also being operative in event of inadvertent adherence of said contacts to forceably displace said armature and separate said contacts due to restraint of said upper portion of the associated insulated conductor in abutment with said frame.

23. In an electric switch, the combination of: a frame having a base and providing a cavity; an armature disposed at least partially in said cavity and universally mounted in continuous conductive relation to said base;

a plurality of rst contacts mounted on said armature;

a plurality of resilient conductors mounted to said frame each having a second contact in paired juxtaposition to one of said rst contacts, each said conductor having a portion thereof normally abutting and restrainable by said frame and relatively exible for movement away from said frame; a corresponding plurality of yieldable elements intermediate the wall of said cavity and said armature to position said armature substantially centermost of said cavity, each of said elements having predetermined spring characteristics; and unitary means connected to said armature oper-fz tive to initially displace said armature against restraint of any of said yieldable elements for eXure thereof to selectively register the corresponding pair of juxtaposed contacts in operative engagement with rapid motion, said means being operative to cause displacement of one of said resiliently mounted second contacts to produce a wiping action between the registering tirst and second contacts.

24. An electric switch according to claim 23 in which said unitary means is operative in event of inadvertent adherence of said registering contacts to forceably displace said armature and separate said contacts due to restraint by said frame of said portion of said conductor in abutment with said frame.

References Cited in the le of this patent UNITED STATES PATENTS 1,912,623 Douglas June 6, 1933 1,912,624 Douglas .Tune 6, 1933 2,240,770 Hammerly May 6, 1941 2,298,802 Meyerhoefer Oct. 13, 1942 2,476,045 Kaminky July 12, 1949 2,508,040 Ransome May 16, 1950 2,521,489 Sorensen Sept. 5, 1950 2,583,756 Wahlberg Ian. 29, 1952

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