US2295518A

US2295518A - Operating mechanism for electric switches

Info

Publication number: US2295518A
Application number: US393608A
Authority: US
Inventors: George J Meuer
Original assignee: Cutler Hammer Inc
Current assignee: Cutler Hammer Inc
Priority date: 1941-05-15
Filing date: 1941-05-15
Publication date: 1942-09-08
Anticipated expiration: 1959-09-08

Description

sept. s, 1942. J MEUER 2,295,518

OPERATING MECHAISM FOR ELECTRIC SWITCHES i Filed May l5, 1941 Patented Sept. 8, 1942 y UNITED sTATEs PATENT oFFlcE y .2,295,513 omarmd Macmmlsiu ron merino swrrcmis George .LMeuer, Milwaukee, Wis., assigner to Cutler-Hammer, lne., Milwaukee, Wis., a oorporation of Delaware Application May 1s, 1941, semi-No. saam v 9 Claims. (Cl. 200-11) This invention relates to improvements in op- Fig. 6 is a fragmentary view, partly in side erating mechanisms for electric switches, and elevation and partly invertical section,-illustrat more particularly for single switch mechanisms ing a slightly modified form of switch operating ofthe double-throw type. mechanism constructed in accordance with my A primary object of the invention is to prol54 invention.

vide a three-pushbutton type of control for a The switch operating mechanisms herein disdouble-throw switch having an intermediate closed are functionally similar to those described off position. and claimed in my application, Serial No. 388,867,

Another object is to provide a three-pushbutfiled March 17, 1941, but diiler from the latter ton operating mechanism for a double-throw, vl A in respect of structural details and in respect three-position switch of well known form. of the use thereof in conjunction with a single Another object is to provide an extremely simple switch of the double-throw, three-position type. and inexpensive pushbutton operating mecha- The particular double-throw, three-positionnism of the aforementioned character. switch which I prefer to employ is of the char- Another object is to minimize the number of 15. acter disclosed and claimed in the application of different parts required to provide pushbutton Alvin W. Krieger, Serial No. 365,907, filed Novem. operating mechanisms having substantially difber 16, 1940, to which reference may behad for a ferent operative characteristics. more detailed description of the switch parts.

Another object is to providenovel interlocking Referring first to the three-pushbutton conmeans to insure against depression of either of trol station illustrated in Figs. 1 to 5, the numeral two of the three pushbuttons, after depression l i0 (Fig. 2)' designates the main body portion of of another of the same pending momentary dean enclosing casing, which body portlonis preferpression of the third pushbutton of the mechaably bent to box-like shape from a single sheet nism. metal blank of suitable form, the inwardly ex- Another object is to facilitate elimination of tending danses Il* and i2* on the end walls Ii the interlock last mentioned, while at all times and I2 of said body portion being rigidly conenabling utilization of the third pushbutton to nected with the side walls, one of which is shown effect off positioning of the switch parts. at il, as lby spot-welding in the usual manner.

4Other objects and advantages of the invention Rigidly attached to the end walls Ii and i2, as will hereinafter appear. .by riveting, are lugs or brackets Il and i5 which The accompanying drawing illustrates certain are respectively provided with tapped openings to preferred embodiments of the invention which receive the shanks of a pair of screws I8, I6, will Anow be described, it being understood that whereby the sheet metal member I1 is removably the embodiments illustrated are susceptible of attached to portion i0, said member I1 acting as modication in respect. of certain structural dea cover for the enclosing casin and as a support tails thereof within the scope oi' the appended for the switch and its operating mechanism. claims. f The double-throw, three-position switch mech- Inthe drawing, anism of the character shown in said Krieger Figure 1 is a top plan view of a single switch, application Serial No. 365,907, comprises essenthree pushbutton control station constructed in 40 tially a molded insulating base i! having a subaccordance with my invention. statially rectangular recess i9 formed therein Fig. 2 is a vertical sectional view, onthe line and opening to the upper surface thereof. The

2--2 of Fig. 1, certain of the switch parts and switch herein disclosed is preferably of the threeoperating elements being shown in side elevation. pole, double-throw type, as best illustrated in Fig. 3 is a fragmentary .vertical sectional view, 45 Figs. 2 and 3. It is to be understood, however, on the line 3-3 of Fig. 1, the main body portion that the number of poles of the particular switch of the enclosing casing and portions of the sheet illustrated may bereduced, if desired, or a diifermetal supporting member being omitted. ent double-throw switch having a greater number Fig. 4 is a fragmentary view similar to Fig. 2, of poles (not shown) maybe employed. Where but showing the operating elements in dierent a multi-pole switch is employed, the barrelative positions. riers (one of which is shown at 20 in Fig. 2)`

Fig. 5 is a sectional view, on the line 6 5 of serve to divide the recess I9 into the required Fig. 3, further illustrating the manner in which number of substantially separate arcing comparteach of the three pushbuttons is restrained ments. Within each arcing compartment is Ail.

against relative rotation, and pair .of longitudinally spaced stationary end cony both of which are contacter upon tilting or Jhe latter to one or the other of its extreme positions. The six stad are provided with like terminal platvc wo of the contacter supports are provided with like terminal members the intermediate contacter support is provided with a 'terminal member 26 of slightly different form, and all of said terminal plates and terminal members are provided with the usual binding screws, as shown.

The means effecting intermediate o3 positioning of the contactors 23, or joint movement thereof to their opposite extreme positions respectively, comprises an insulating block 21 carrying three spring-pressed plungers 28 for cooperation with the respective contactors, block 21 being engaged by the forked or notched lower end 2Sa of a lever 29 which is pivotally supported by a pin 30 carried by brackets 3|, 3| attached to the bulged cover plate 32 which is rigidly secured to the upper surface of base I8, as by means of a pair of metal eyelets 33. As shown, lever 23 is preferably of laminated form.

Lever 29 is provided with a pair of integral oppositely extending

arms

29b and 29c the enlarged outer end portions of which are provided with substantially circular openings 29d and 29e, which are adapted to accommodate

pivot pins

34, 34 of relatively smaller size than said openings (see Fig. 2).

Pins

34, 34 penetrate openings .provided in pairs of lugs 35a formed integrally with

plates

35, 35 which respectively underlie the lower ends of a pair of

end pushbuttons

36 and 31, molded from any suitable insulating material. Pushbuttons 36 and 31 are preferably of like form structurally, the same differing only in respect of the legends applied thereto, as indicated at 38 and 31c in Fig. l. As shown at the left hand end oi' Fig. 2, each

pushbutton

36 and 31 is provided with a substantially cylindrical recess 38 and with a hollow substantially cylindrical metal insert 33, whose reduced lower end 39a is upset over the lower surface of its associated plate 35 to` rigidly secure the same to its

respective button

36 or 31.

As shown in Figs. 4 and 5

buttons

36 and 31 are provided on the lower surfaces thereof with pairs of studs 36D, 345b and 31h, 31b molded integrally therewith and closely positioned on opposite sides of a reduced portion of each plate 35 to positively insure against rotary displacement of the respective button relatively thereto.

As best illustrated in Fig. 2, a at sheet metal plate 40 is superimposed upon the cover plate 32 and is also rigidly secured in position, as by means of the aforementioned eyelets 33, plate 40 having an opening 40e (Fig. 2) to accommodate the bulge in cover plate 32. Inasmuch as the purpose of plate 40 is primarily to afford a greater area than is provided by theplate 32 (which is standard with a switch of this character), it will be apparent that the result contemplated may likewise be attained by correspondingly increasing the dimensions of plate 32.

As shown, plate 40 has rigidly attached thereto at each end thereof a metal stud 4|, as by upsetting the reduced lower end 4|I of the latter over the lower surface of said plate. Studs 4|, 4| are surrounded by

coiled springs

42, 42 whose upper ends bear at all times under a predetermined degree of compression against the upper end walls of the button recesses 33 aforementioned. As best illustrated in Fig. 2, the studs 4|, il are of a length to extend within the recesses in the respective buttons in the normal positions thereof corresponding to the ofl" position oi the switch mechanism, while the recesses 38 are of such height as to provide clearance for said studs upon extreme lower positioning of each button (see the right d of Fig. fl). Also, as shown at the left and end of Fig. 4, in 'the upper extreme position of either of said buttons the spring i2 will, act to insure proper allnement thereof with respect to associated stud 4| to assisi, limiting each of said buttons to reciprocating movement a straight line.

To further assist in restricting

buttons

33 and 31 to straight line reciprocating movements I prefer to provide member i1 with openings to accommodate each button with a fairly close sliding fit, each opening having associated therewith an upstanding peripheral flange |1, I1, for

a similar purpose.

In practice the

springs

42, 42 are of suflcient strength individually to elect return of the various parts thus far described to the positions thereof illustrated in Fig. 2 upon manual release of either of the

pushbuttons

36 or 31 after depression thereof, it being obvious that the lever 29 acts to insure against simultaneous depression of both of said end buttons, whereby all possible strain upon the switch contactors and contacts is prevented. It is likewise obvious that the form of the switch contactors and the operating elements associated therewith (other than the pushbuttons 36 and 31) are such as to inherently prevent engagement of said contactors with the opposite end contacts simultaneously.

However, I prefer to provide means for latching the switch mechanism in either of its extreme on positions, and to provide for manual return of the switch mechanism to its intermediate "oil" position. For this purpose lever 23 is provided with an upward extension 23 having an opening or slot 29! of approximately U-shape formed therein. The third or intermediate pushbutton 43 of the station has formed therein by the molding operation a downwardly opening recess 43* extending throughout the major portion of the length thereof, the form of said recess in transverse cross section being best illustrated ln Fig. 5, and the transverse dimensions thereof being such as to freely accommodate the upright portions of brackets 3|, 3| and the enlarged opposite ends of pin 30. The opposed walls of recess 43l are provided with alined slots 43b and 43, of somewhat less height than the recess, said slots being adapted to provide clearance for the arms 2lih and 23 and extension 23f of lever 23 during oscillatory movements of the latter.

Button 43 is further provided with a diagonally arranged pair of downwardly opening auxiliary recesses 43d and 43 of relatively small height (as indicated in dotted lines at 43 in Fig. 3) to accommodate a pair of coiled

compression springs

44, 44 whose lower ends are respectively seated upon the horizontal portions of brackets 3|, 3|. Springs 44 act to bias button 43 upwardly beyond the normal position thereof shown in Fig. 2, but said button is normally restrained against further upward movement by a pin 45 positioned within an opening or passage drilled transversely through said button, said passage having enlarged or countersunk outer ends (as shown in Fig. 3) to assura i 3 laocoini'nodate the head and the upest end of said pressed. Alsoas aforestated this pushbu/tton stapin. l l tion insures against simultaneous closure of the As aforestated, the lever 2l is biased by springs alternative circuits for the controlled motor. The 42 to its intermediate position shown in Pig. 2, pushbutton station specifically illustrated in Figs. which position it will assume when button 43 is 5 1 to 5 may be employed as-a two-speed acrossmanually depressed. Upon manual release of the-line starter for a three-fourths H.- P., A. C. button 43 the pinv 4l carried thereby will ensingle or polyphase motor at 110 to 230 volts. gage the short horizontal edge portion 29*I of In the modification illustrated in Fig. 6, it is slot 29, thus limiting th'e degree of upward moveto be understood that the switch base (not ment of said button. Assuming that the right shown) and the parts located therein or carried hand end button 31 is thereafter depressed, as thereby may be identical with those illustrated shown in Fig. 4, it is obvious that the aforemenin Figs. 1 to 5. The supporting and operating tioned edge portion Vof the U-shaped slot will parts shown in Fig. 6 are also in many respects move out of restraining relation to pin 4l and identical with, or substantially like the correthe -latter will be freed to move upwardly into sponding elements aforedescribed,th'e structuralthe left hand end portion 231 of said slot under ly and functionally identical parts or portions of the upward bias of springs 44 upon button 43. the two devices being given like numerals of ref- Such positioning of pin 46 wi in the left hand erence. Thus the parts 3l, 3,2, 4l, I1, 4l, 44, 41, end of said slot (Fig. 4) positi ely restrains

lever

34 and 35 may be identical with those aforede- 29 against counterclockwise movement, thus 20 scribed. The lever 29l may be formed from the positively preventing depression of left hand end same blanks as the lever 29 aforedescribed, but button 39. However, upon momentary depresthe upward extension 291 of lever 29 (and the slot sion of button 43 all of the parts will assume the 29 located therewithin) is preferably omitted positions thereof illustrated in Fig. 2, and therefrom lever 29x, the portion 29, and arms 29 and after either of the

end buttons

36 or 31 may be 25 29 of lever 29I being the same as those portions manually depressed individually, and the same of lever 29. Itwill be understood, of course, that will be latched in its depressed position, by the the lever 29 aforedescribed might be used, withaction of pin within one end or the other of out any change, in the device of Fig. 6, but there slot 29', is no requirement in the latter device for the Thus, with' the parts as shown in Fig. 1, it ls 30 aforedescribed functions of slot 29'. obvious that upon depression ofvleft hand end Thus the intermediate or Stop button 43l button 39 lever 29 will be moved counterclockof Fig.' 6 may be produced in the same molding wise until pin 45 is freed to move upwardly into die as the button 43 aforedesciibed; but the translatchin engagement with the right hand end 291 versely drilled passage of button 43 is omitted of slot 29|, whereupon button 36 will be retained 35 from button 43X, inasmuch as the aforedescribed in its depressed position and button 31 will be pin 45 is not employed in the device of Fig. 6. positively restrained against depression pending Instead, the button 43x is provided at a predemomentary depression of button 43 termined point in its length with a peripheral The support member l1 is provided with an groove 43y of semi-cylindrical form in transverse intermediate opening of circular form which is 40 cross section, said groove being preferably formed adapted to receive the reduced lower end of a therein by a milling or grinding operation. A guide tube or flange member 46, said reduced end spring ring 48 is forced onto button 43l and being spun outwardly over the inner surface of snaps into position within groove 43", the open member l1, as sh'own at 46, whereby member end of ring 48 being positioned as shown in Fig. A4I acts to insure reciprocating movement of but- 45 6, or at a point 180 degrees removed therefrom.

ton 43 in a substantially straight line. Ring 49 engagesr the upset end or flange 46 of The switch mechanism, including the various tubular member 46 to limit the degree of upward operating elements thereof aforedescribed, is atmovement of button 43", under the bias of springs tached to member I1 as by means of four like 44,as aforedescribed. The opposite end buttons studs or spacing members 41,whose reduced lower 50 36l and 31a may be structurally quite similar to ends (not shown) penetrate correspondingly the

buttons

36 and 31 aforedescribed, except that sized openings in plate 40 and are upset over the button 36 preferably is provided at its upper end lower surface of the latter. The enlarged flat with the legend For (meaning forward") and upper ends 41h of members 41 seat against the button- 31 is provided with the legend Rev inner surface of member I1 and are rigidly at- 55 (meaning reverse). tached thereto by spot-welding. The springs` 49, 49 associated with buttons 36 As best illustrated in Fig. 5, th'e plates 35 exand 31* are formed of substantially smaller gauge tend laterally beyond the pushbuttons 36 and .wire (and are consequently of less strength) than 31 to cooperate with the under surface of memthe springs 42 aforedescribed; the arrangement ber I1, to limit the degree of upward movement o being Such that upon depression of either button of each button, as indicated at the left hand end 36* or 31* the same wil1`be retained in depressed position by the action or bias of the springs asof Fig. 4.

with reference to Fig. 1 the end buttons 35 sociaid with the svlitch contactors, and against and 31 may bear the legends S10w and Fast the s ght upward b as of the respective springs 9. Also as will be obvious from Fig. 6, it is posand the intermediate button 45 may bear the b Sto Assuming that the pushbutton sible to alternately depress the uttrns 36 and 1523:; is uid for control of a two speed two 31B, for circuit commutation, without interfernbthSt t ill winding, squirrel cage motor on a light duty apseciaed ewithohebt- :Golf :gg Sge :gx RUSS-tial); Suclh afngsinarll upon depreson of ceither button 36a or 31, the s o v ous a a r same may move upward y o its normal or or locking One 0f the Speed-601111101 buttons (35 circuit interrupting position by momentarily deor s1) the other of said speed-control buttons pressing button 43X, the ring 4s acting under this cannot be depressed until the intermediate condition upon one or the other of the arms 29 Stop" button 43 has been momentarily de- 75 (as indicated in Fig. 6) or 29h to return lever 29x to its intermediate or circuit interrupting position. The arrangement disclosed in Fig. 6 affords the advantage of providing for reversing or stopping the controlled motor by plugging, the button 43x being momentarily depressed to eiIect circuit interruption of the plugged motor in the event that it is desired to completely stop the same. Thus the device of Fig. 6 acts as a reversing across-the-line starter for light duty motors of the rating or capacity mentioned in connection with Figs. l to 5.

It will be understood that the legends applied to the several pushbuttons employed may diier from those illustrated, according to the requirements of the particular installation. In like pushbuttons to resiliently retain each of the same f in its lower extreme position when depressed semanner the circuit connections to the wiring ter- Y minals of the switch may be effected in various different ways to provide for performance of many different electrical functions by either or both of the pushbutton control stations herein disclosed.

I claim:

1. As an article of manufacture, a manually operable switch assembly of the pushbutton type comprising, a fiat punched sheet metal supporting member, a unitary double-throw switch mechanism secured to said supporting member, actuating means for said switch mechanism comprising a pair of opposite end pushbuttons and a third pushbutton located therebetween, a pivoted rigid lever having oppositely extending arms to which said end pushbuttons are respectively pivotally connected, a pair of coiled compression springs interposed between the respective end pushbuttons and said supporting member, whereby said end pushbuttons are normally biased toward their upper extreme positions, said lever cooperating with said end pushbuttons to positively prevent simultaneous depression of both of the same, each of said end pushbuttons when depressed being adapted to effect a circuit completing operation of said switch mechanism, associated means common to said end pushbuttons and operable automatically to retain either of the same in its lower extreme position when depressed, said third pushbutton being springbiased toward its upper extreme position, and said third pushbutton having a part thereof cooperable with said lever and adapted upon temporary depression of the former to eiect return of either of said end pushbuttons from its depressed position, to thereby effect circuit interrupting operation of said switch mechanism.

2. In a pushbutton operated single switch mechanism of the double-throw type, in combination, a first pushbutton, a plurality of contacts adapted to be engaged with each other upon depression of said pushbutton to eiiect completion of an electric circuit, a second pushbutton, a second plurality of contacts, including certain of said first mentioned contacts, adapted to be engaged upon depression of said second pushbutton to effect completion of a different electric circuit, means including a fixedly pivoted rigid lever having a pivotal connection with each pf said -pushbuttons to positively restrain said pushbuttons against depression thereof simultaneously to thereby insure against completion of both of said electric circuits at one time, means including a coiled compression spring interposed between each of said pushbuttons and a supporting element of said switch mechanism to normally bias the same toward their upper extreme positions, thereby tending to interrupt both of said electric circuits, spring-biased means common to said lectively, either of said first or second pushbuttons when depressed being adapted to effect upward movement of the other of the same, if depressed, against the action of said spring-biased means, to thereby provide for alternate completion of said first and second mentioned circuits individually, and means comprising a third pushbutton having a part engageable with said lever adjacent the point of pivotal support of the latter and adapted when momentarily depressed to effect upward movement of either of said first or second pushbuttons, if depressed, whereby both of said electric circuits are interrupted.

` 3. In a pushbutton operated single switch mechanism of the double-throw, multi-pole type, in combination, a metal supporting member, a one-piece molded insulating base secured to said supporting member, said base having a recess formed therein and opening to the upper surface thereof, a plurality of stationary contacts arranged at each end of said recess, a plurality of contactors located in said recess and tiltable into and out of engagement with the opposite end contacts respectively, means Afor effecting tilting movements of said contactors, said means comprising a pivoted lever having oppositely extending arms, a pair of end pushbuttons respectively pivotally connected with said lever arms, said lever acting to positively restrain said pushbuttons against depression thereof simultaneously, for the purpose set forth, a pair of coiled compression springs interposed between said supporting member and the respective pushbuttons to normally bias the latter out of their depressed positions, thereby tending to effect disengagement of said contactors from all of said contacts, a third pushbutton spring-biased toward its upper extreme position, said lever having an approximately U-shaped slot and said last mentioned pushbutton having a transverse pin cooperating with the walls of said slot to positively latch either of said end pushbuttons in its lower extreme position when depressed, said third pushbutton when momentarily depressed effecting movement of said pin relatively to the walls of said slot, whereby the depressed end pushbutton is unlatched to provide for disengagement of said contactors from all of said contacts, and said third pushbutton, said pin and the walls of said slot forming the sole means for effecting release oi'either of said end pushbuttons when depressed. 4. In a pushbutton operated single switch mechanism, in combination a first pushbutton, a stationary contact, a pivoted contactor movable into engagement with said contact upon depression of said pushbutton to effect completion of an electric circuit, a second pushbutton, a second stationary contact, said contactcr being movable into engagement with the latter upon depression of said second pushbutton, means including a pivoted rigid lever having a pivotal connection with each of said pushbuttons to positively restrain the latter against simultaneous depression, to thereby insure against completion of more than one of said circuits at a time, a pair of coiled compression springs respectively associated with said pushbuttons to normally bias the same toward their upper extreme positions, thereby tending to interrupt both of said electric circuits, switch mechanism including spring-biased parts common to said pushbuttons to retain either of the same in its lower extreme position when depressed selectively, against the action of the re- .awningsd spective coiled compression springs demtioned. said last mentioned reans including a third pushbutton spring-biased toward its upper extreme position and having a part adapted in such position for latching engagement with said l lever, and said third pushbutton being adapted when momentarily depressed to permit the aforementioned normalv spring-biased movement ot said iirst or second pushbutton toward its upper extreme position. it depressed, whereby both of =l said electric circuits are interrupted.

5. In a pushbutton operated single tch` mechanism of the double-throw type. in co ination, a metal supporting member, a one-pi e molded insulating base secured to said support'-l .15 ing member, said base having a recess tormed. therein and opening to the upper surface thereof, a stationary contact arranged at each end'oi said recess, a contactor located in-said recess and tiltable into and out of engagement with the opposite end contacts selectively, means for effecting tilting movement of said contactor, said means comprising a pivoted lever having oppositely extending arms, a pair of end pushbuttons respectively pivotally connected with said lever arms, said lever acting to positively restrain said pushbuttons against depression thereof simultaneously, for the' purpose set forth, a pair of coiled compression springs interposed between said supporting member and .the respective pushbuttons to normally bias the lattersout of their depressed positions, thereby tending to effect disengagement of said contactor from both of said contacts, a third pushbutton spring-biased toward its upper extreme position, said lever having an approximately U-shaped slot, said last mentioned pushbutton having arecess to accommodate the slotted portion of said lever and a pin extending transversely therethrough for cooperation with the walls of said slot to positively latch either of said end pushbuttons in its lower extreme position. said third pushbutton when momentarily depressed effecting movement of said pin relatively to the walls of said slot, whereby the depressed end pushbutton is unlatched to provide i5 for disengagement oi said contactor from both. of said contacts, said third pushbutton, said pin and the walls of said slot forming the sole means for Yetlecting release of either of said enti` pushbuttonsr when depressed, and means comprising a metal plate rigidly secured to and spaced upwardly from said supporting member, said plate having openings formed therein to accommodate each of said pushbuttons and to assist in restricting the same to reciprocating movement in a straight line.

'6. In a pushbutton operated single switch mechanism of the double-throw type, in combination, a metal supporting member, a one-piece molded insulating base secured to said supporting 00 member, said base having a recess formed therein and opening to the upper surface threoi, a stationary contact arranged at each end of said recess, a contactor located in said recess and tiltable into and out of engagement with the opposite end contacts selectively, means for effecting tilting movement of said contactor, said means comprising a pivoted lever having oppositely extending arms, a pair ofend pushbuttons respectively pivotally connected with said lever arms, said lever acting to positively restrain said pushbuttons against depression thereof simultaneously, for the purpose set forth, a pair of coiled compression springs interposed between said supporting member and the respective pushbuttons to for disengagement of said Y a pair o! studs latter out of their depressed positions, thereby tending to effect disengagement of said contactor from both o! said contacts. a third pushbutton spring-biased toward its upper extreme position, said lever having'an approximately U-'shapedslot, said last mentioned pushbutton having a recess to accommodate the slotted portion f said lever and a pin extending transversely therethrough for cooperation with the walls of said slot to positively latch either of .f d end pushbuttons in its lower extreme position, said third pushbutton when momentarily normally the depressed eilecting movement of said pin relatively to the walls of said slot, whereby the depressed end pushbutton is unlatched to provide contactor from both of said contacts, said third pushbutton, said pin and the walls of said'slqt forming the sole means for eil'ecting release of either of said end pushbuttons when depressed. means comprising a metal plate rigidly secured to and spaced upwardly from said supporting member, said plate having openings formed therein to accommodate each of said pushbuttons and to assist in restricting the same to reciprocating movement in a straight line, and rigidly secured to said supporting member and extending upwardly within said springs, said end pushbuttons being recessed to accommodate the upper end portions of said springs and said studs to further assistin restricting the former to reciprocatingy movement in a straight line. e.

'1. In a pushbutton operated single switch mechanism of the double-throw type, in combination, a metal supporting member, a one-piece molded insulating base secured to said supporting member, said base having a recess formed therein and opening to the upper surface thereof, a stationary contact arranged at each end of said recess, a contactor located in said recess and tiltable into and out of engagement with the op-v posite end contacts selectively, means for ee'cting tilting movement of said contactor, said means comprising a pivoted lever having oppositely extending arms, a pair of end pushbuttons respectively pivotally connected with said lever arms, said lever acting to positively restrain said pushbuttons against rotation and against depression thereof simultaneously, for the purpose set forth, a pair of coiled compression springs interposed f between said supporting member and the respective pushbuttons to normally bias the latter out of their depressed positions, thereby tending to effect disengagement of said contactor from both of said contacts, a third pushbutton springbiased toward its upper extreme' position, said lever having an approximately U -shaped slot, said last mentioned pushbutton having a recess to accommodate the slotted portion of said lever and a pin extending transversely therethrough for cooperation with the walls of said slot to positively latch either oi' said end pushbuttons in its lower extreme position, said third pushbutton when momentarily depressed effecting movement of said pin relatively to the walls of saidslot, whereby the depressed end pushbutton is unlatched to provide for disengagement of said contactor from both of said contacts, said third pushbutton, said pin and the walls of said slot forming the sole means for eecting release of either of said end pushbuttons when depressed, means comprising a metal plate rigidly secured to and spaced upwardly from said supporting member,

-said plate having openings formed therein to accommodate each of said pushbuttons and to assist in restricting the same to reciprocating movement in a straight line, a pair of studs rigidly secured to said supporting member and extending upwardly within said springs, said end pushbuttons being recessed to accommodate the upper end portions of said springs and said studs to further assist in restricting the former to reciprocating movement in a straight line, said third pushbutton having a kerf formed therein and opening to the lower end thereof, and said lever cooperating with the walls of said kerf to restrain said third pushbutton against rotation and to further assist in limiting the same to reciprocating movement in a straight line.

8. As an article of manufacture, an operating superstructure for an electric switch of the threeposition, double-throw type, comprising a metal cover plate, a double-armed lever pivotally supported by said cover plate, a pair of end pushbuttons respectively pivotally and non-rotatably connected with thearms of said lever, a pair of studs rigidly attached to said cover plate, a coiled compression spring surrounding each stud and engaged under compression with each of said pushbuttons, said pushbuttons having recesses to accommodate the upper ends of said springs and said studs to assist in limiting the former to reciprocating movements in a substantially straight line, a third pushbutton slidably associated with said lever and restrained thereby against rotation relatively thereto, means for limiting the degree of upward movement of said third pushbutton, spring means interposed between said cover plate and said third pushbutton to bias the latter toward its upper extreme position, said third pushbutton when depressed being adapted to provide for upward movement of either of said end pushbuttons, if depressed, and a sheet metal supporting member rigidly attached to said cover plate and spaced upwardly from the latter, said supporting member having peripherally flanged openings formed therein to accommodate the respective pushbuttons and to also assist in limiting the same to reciprocating movements in a substantially straight line.

9. As an article of manufacture, an operating superstructure for an electric switch of the threeposition, double-throw type, comprising a metal cover plate, a double-armed lever pivotally supported by said cover plate, a pair of end pushbuttons respectively pivotally and non-rotatably connected with the arms of said lever, a pair of studs rigidly attached to said cover plate, a coiled compression spring surrounding each stud and engaged under compression with each o! said pushbuttons, said pushbuttons having recesses to accommodate the upper ends of said springs and said studs to assist in limiting the former to reciprocating movements in a substantially straight line, a third pushbutton slidably associated with said lever and restrained thereby against rotation relatively thereto, spring means interposed between said cover plate and said third pushbutton to bias the latter toward its upper extreme position, said lever having a substantially U-shaped slot formed therein, said third pushbutton having a pin extending transversely therethrough for cooperation with the walls of said slot to latch either of said end pushbuttons in its lower extreme position when depressed, each of said coiled compression springs acting to bias its respective end pushbutton toward its upper extreme position, and said third pushbutton when depressed being adapted to eii'ect unlatching of either of said end pushbuttons with consequent movement thereof from its depressed position, said pin also cooperating with the walls of said slot to limit the degree of upward movement of said pushbutton last mentioned.

GEORGE J. MEUER.