US2451618A

US2451618A - Combined thermal and magnetic

Info

Publication number: US2451618A
Authority: US
Publication date: 1948-10-19
Anticipated expiration: 1965-10-19

Description

Oct. 19, 1948. H. R. GRcss 2,451,618

COHBINED THERMAL AND MAGNETIC FLASHER SWITCH 4 Sheets-Shee't 1 Filed Oct. 14, 1943 n u I ul v n u A www... l' mn;

/ll dit..

IN VEN TOR. J/erzyj 611055 @kfgmM/Q,

v 4 Sheets-Sheet 2 H. R. Goss COMBINED THERIAL AND MAGNETIC FLASBER SWITCH oct. 19, 194s.

Filed Oct. '14, 1943 Oct. 19, 1948. H. R. GROSS 2,451,618

- COMBINED THERML AND MAGNETIC FLSHER SWITCH 4 Sheets-Sheet 3 Filed Oct. 14, 1943 Get. 19, 1948, H. aGRossA 2,451,618

COIIBINED THERMAL AND MAGNETIC E LASHEB SWITCH Fixed ot. 14. 1943 4 sheets-sheet 4 '-J -Jv/ INVENTO Patented Oct. 19, 1948 OFFICE' CONIBINED THERBIAL AND=MAGNETIC1 l FLASHER SWITCH. 1

Henry R.. Gross, Chicago, lll. Application October 14, 1943, Serial N o.506,161`

2 Claims. (Cl. 20o-88) This invention relates to an improvement in flashers, and more particularly to improvements in thermo-responsive flasher switches controlling turn signal systems,

An object of the invention isto provide a universal auto signal flashenswitch, i. e.,.one which shall be capable of incorporation in all, or substantially all, automobile lamp' flashing signal systems. 4

Prior iiashers embodying l thermo-responsive switches have not proven entirely satisfactory because of difficulty lin manufacturing; relatively high loss or breakage in manuiacturing,..uncer tain in operation, relatively high in rcost,'and be cause of inherent' limitationsin Vtheir- 'structure preventing their use in different signa'lcircuta so that it was notv always possible to secure the particular model required fora particular' auto,

and considerable confusionQ existed in .determining which model was appropriate ioranyparticu lar auto. I-t is, accordingly, animportant object of the invention to overcomethese difliculties, insutliciencies and provide a flasher switchoi' uniform construction for ali.= orsubstantially all auto turn and stop signal systems.

It is a further obiectoi'theinvention to pro,v

vide a nasher device which :is ruggedin construction, inexpensive to manuiacture,'certain in'operation and of relatively low cost.

Flasher switches employing contacts operated by thermo-responsive or bimetailicmembers have inherently a relatively short operating'life by' reason of the fact that they move slowly inbeing heated or cooled so thatv the contacts are" separated rather slowly and are initially engaged with a very light pressure.- This causes arcing and, hence, excessive -wear of the contacts.' Toggles or other devices between the bimetallic members and the contacts, which cause=thetcontacts to snap into or out ofengagement, are not satisfactory by reason of their added cost and the tendency of such devices to stick under adverse weather conditions an'd under adverse operating conditions encountered when instal-led in' automobiles to control the signal lights thereof.A It is essential that a device employed for this purpose be entirely reliable in operationtfor 'accidents will, and do, frequently happen because the operator falsely relied on adevice to signal his intentions to turn or stopthexvehicle. It is. therefore, an important object of the invention to provide a flasher switch employing a thermoresponsive or bimetallic member which directly controls or actuates switch contacts controlling the operation of signal circuits, which switch is 2. reliable in operation" and inherentlycapabiewof. operation over long periods of time and fyetirela-'il tively low in cost.

It is a further objectof the invention to provide:a iiasher switch oi the character described in combination with improved signal circuits; simplifying the wiring of turn 'signal systems-and combined turnvsignal' and lbraire controll systems;-

It is more particularly an obgectroi. the inverte tion--to provide a iiasherof-r'the.':chara"ct'er`de scribed and signal circuits thereforg'by meansl ot which the ilasherimay bei incorporated in'tautomobile electrical circuits regardlessv oi thetype' of the circuit.

Other and further objects and advantages of the invention -will be apparent from theI following de'scriptio'nwwhen taken irl-connection 'witli'the accompanying drawings, wherein-- Figure 1 is a View inperspective 'of' aiiiashr device' embodying theV invention;

Figure 2 isa view in vertical'section taken substantially along. the line 2-v-2 ofFigure 3;V

Figure 3 is a view in vertical section .taken s uli-- stantiallyalong the line 3.-'-3 oilig'ure 1J- Figure 4 is an enlarged view in, substantiallyhorizontal section taken along. the line' l-Q of Figure .1:

Figure 5 is an enlarged view-in substantially horizontal section takenelonglthe line' of Figure l;

Figure' 6. is a view in explodedrersnwtlve cf.- certain' parts of ther'asher device;

Figures 'I to 1 5 are schematic' diagrams-otI ci r. cuits in which the flasher. Figures 1 to 5f may fOr-m a part;

Figure i6 is a view in section similar to Figure 5 of `a modiiicationof the flasher shown in Figures l to 5;-A

Flgures i7 to 20 are -schematic diagrams ofcircuits in which the iiasher, Figure -16,may 1iorm= a part;

Figure 21 is a view in section similar to Figure 2 showing a further. improvement of theA asherfof- Figure 2;

Figuresv22 to 25. are views in section 4similar to` Figure 4 for illustrating operation ofthe further improved ilasher of Figure 22; and

Figure 26 is a schematic diagram of a circuit in-which the iiasher of Figures 2l to 25 mayvbe incorporated.

As shown in the drawings, the flasher 2 (Fig-- ures 1 to 5) may comprise a stamped sheet metal. pan-shaped housing 4 having a perpheralollsetv 4flange 6 forming at the open mouth of the hous-Y` ing a seat for a iiat plate 8 of insulating material and having around its free edge lugs I8 bent over the outer face of the plate 8 and securing the same in assembled position, A mounting strap I2, preferably of sheet metal, is spot welded or otherwise fastened to the housing and is appropriately apertured or slotted to receive a mounting stud, bolt or other supporting means.

A generally T-shaped magnetic core piece or member I4 is mounted on the inner surface of the insulating plate 8, as by rivets I6 and spacing members I8. A relay coil 28 of magnet wire ls wound upon the core I4 between the end cross member 22 and the enlarged opposite end portion 24. A cross piece or bar 26 of magnetic material is fixed to the end 24 of the core I4, preferably by one of the rivets which mounts the core member on the insulating plate. This crossmember 26 has welded to it at one end a resilient contact blade or strap 28 which extends theree from toward the cross-bar 22. The cross member 28 has similarly Welded to it at the opposite end a resilient bimetal switch member 38, also extending therefrom toward the cross-bar 22. The bimetallic switch member 38 is preferably of such material and so dimensioned as to operate at a temperature of approximately BOOPF. Hence it is substantially insensitive to changes in atmospheric temperature. Since the difference between the highest and lowest atmospheric temperatures likely to be encountered is very small in respect to the operating temperature of this bimetallic member, its heating and cooling time period is substantially unaffected by atmospheric temperatures.

The switch blade 28 is welded at its free end to a thin strip 32 of magnetic material which extends therefrom over the cross-bar 22 so as to form an armature, attracted to the cross-bar when the coil of the relay, of which the core member forms a part, is' energized. The bimetallic switch member 38 is similarly welded at its free end to a light, thin strip 34 of magnetic material which also extends therefrom over, the crossbar 22 to form an armature of the relay. The,`strap 32 carries on its under surface a contact 36, and the strap'34 similarly carries a contact 38. Contact 36 cooperates with a contact 48^supported therebeneath by a sheet metal bracket 42 fastened to the plate 8 by the inwardly bent lugs 44. A terminal bracket 46 is mounted on the outer surface of the plate 8. The lugs 44 are formed intergral with the terminal bracket 48,eiitend through suitable openings in the plate 8, and are bent over the bracket 42, thus securing both the terminal bracket and the contact carrying bracket to the insulating plate. The terminal bracket 48 carries the usual terminal screw 48. The contact 38 cooperates with the contact 58 carried by a bracket 52, similar to the bracket 42, which is similarly secured to the plate 8 by the lugs of a terminal bracket 54 corresponding to the bracket 46. The terminal bracket 54 carries the usual terminal screw 56.

The

terminal brackets

48 and 58 are mounted in laterally spaced relation at one end of the insulating plate 8. A terminal bracket 58, similar to the brackets 4E and 54, is mounted at the opposite end of the plate 8, as by lugs 68 which pass through suitable openings in the plate and are bent over against the inner surface of the plate. The end 52 of the relay coil 28 is secured to the lugs 68 of the terminal bracket 58, while the opposite end 84 of the coil is welded to the cross-member 25 and connected by that mem- 4 ber of the core to the switch blade 28 and bimetallic member 38.

The gap between the

contacts

36 and 48 and the

contacts

38 and 58, when the contacts are in open positions, is determined by the readily bendable oppositely directed

lateral arms

86 and 68 of a sheet metal member I8 secured in position to the cross-arm 22 of the core member I4 by the rivet i8 which fastens one end of the core member. As shown in Figure 5, the normal bow of the resilient switch blade 28 is such as normally to hold the contact 38 in open position. The normal undeected shape of the bimetal member 38 is such as to hold the contact 38 in engagement with the contact 58, as shown in Figures 3 and 4. As the bimetal member, on being heated, reaches a temperature of about 800 F., the defiecting force built up in the member by such heating becomes greater than the magnetic holding force between the armature piece 34, carried by the bimetal member, and the cross-arm 22 of the core member. The contact 38 is thereby lifted out of engagement with the contact 58 and, when the contact 38 separates ever so slightly from the contact 58', the circuit to the relay coil 28 is broken, as will hereinafter be described, the relay coil is deenergized and the magnetic force of attraction between the armature 34 and the crossbar 22 of the core member thereupon disappears, and the deecting force built up in the bimetal member is enabled to move the contact 38 more swiftly away from the contact 58.

As the bimetal member cools and contracts, the contact 38 is moved, relatively slowly, thereby toward the contact 58. When the contact 38 touches the contact 58, the relay coil 28 is again energized and the magnetic force generated between the armature and the cross-bar 22 of the core memher immediately pulls the contact 38 into firm engagement with the contact 58.

The gap between the contacts 36 and contact 48 is so adjusted by bending of the strip 68 that when the relay coil 28 is energized, the armature 32 is snapped down, bringing the contact 36 into engagement with the contact 48, and the resilient contact blade 28 is so dimensionetl as to cause thecontact 38 to-snap tout of engagement with the contact 48 when the relay coil is deenergized.

As shown in Figure 7, the iiasher device 2 may be connected in a circuit to control auto turn signals and a single grounded pilot light which serves to indicate whether the turn signal circuits are operating. The terminal 58 of the asher is connected by a wire I2 to the positive or ungrounded side of a battery 14. or other source of electric energy provided in the auto or vehicle. The negative side of the source I4 is grounded at 16,as is common. The outer surface of the insulating -rplate 8 adjacent the terminal 58 is marked with a plus sign i8 (Figure 1) to indicate that this terminal is to be connected to the positive or ungrounded side of the electric source.

The terminal 54, which is connected by the bracket 52 to the contact 58, as shown in Figure 4, is connected with wire 88 (Figure '7) to the movable switch blade 82 of the main turn signal control and selector switch 84. The switch 84 has additionally a pair of

contacts

86 and 88, the contact 88 being connected by wire 98 and

wires

92 and 84 in parallel to the front and rear left

turn signal lights

-the closing of the switch 84. light, although normally disconnected from the- .to the contact 40, as shown in Figure 5, is connected by wire H8 to a pilot light lllwhich is grounded as at i22.

A Upon operation of the main control .or selector .switch 84, as, for example, to move .blade B2 -into engagement with contact 86, a circuit is completed from the source or battery 14 through wire 12, terminal 5B, relay coil 20 and cross-piece 26 of the core member I4 to the switch blade 2-8 and bmetal member 30.

From the bimetal member 30 the circuit is completed through the contact 36, contact Sil, with which it is at this time in engagement, the terminal 54, the wire 80, the switch blade 82, the contact 8E, the wire 9D and the wires 92 and 9d to the left

turn signal lights

96 and 98. The circuit for the relay coil being thus completed through the bimetal member to the signal lights, the coil is energized and the amature 32 is thereby pulled down to cause the contact 35 to engage the contact 4o and complete the circut from the switch blade 2B through the

contacts

36 and 40, the terminal 48 and the wire H8 to the 'pilot light |20.

Since the

contacts

38 and 50 controlled by the bimetal member are in closed position when the bmetal member is cooled and, therefore,'closed when the switch 84 is open, the relay is energized instantaneously upon the closure of this latter switch and causes the switch comprising the

contacts

36 and 40 to be closed instantaneously .with Hence the pilot source, is connected thereto Vsimultaneously with the energization of the turn signal lights.'

The current to the signal lights passes through the bimetal member 3G, which is o! such resistance as to cause self-heating at a predetermined rate.'

determined, of course, by the magnitude of the current supplied to the signal' lights. v'As previously stated, the bimetal member is one rated to operate at a temperature of 800?. As it becomes heated above this temperature, it tends to curl up on its outer end. Such deflection of the bimetal member is resisted by the magnetic torce or the relay exerted on the armature 34. When the detlectlng force built up in the birnetal Amember ex cee@ the magnetic holding ,force `pf tlie relay. the contact 38 is moved by the bimetal member away from the contact 50. Assoon as the contact 38 disengages ever so slightly from the contact ,50, the circuit to the-signal lights is broken Vand the lights are, therefore, d een'ergized.

It should be noted that the pilot light |20 is preferably of such resistance. that the current which may be supplied to it is insumclent to hold the relay operative. i. e., the magnetic force which is created by that currentnowing through the relay is insufilclent to' hold the switch blade 428 in contact closing position. .Hence the contact 36 is snapped by the resilient contactblade 2B out oi engagement with the contact 40 at the same instant that the contact 3B disengages the contact 5D. The pilot light i2!) is. therefore. deenerglzed simultaneously with the deenergizanon of rino zum signal lights.

Af; the bimetal member 30 cools below the operating temperature. it contracts and moves the Contact 38, relatively slowly, toward the contact 5B and into engagement therewith. As soon as the Contact 38 ,engages the contact, the circuit through the relay coil. and:thesignalllghts,is

completed and the magnetic force of :the relay exerted on the amature 36 presses thecontact 38 .into tlrm engagementwiththe contact 50. Hence '.thesignal lights.. and the pilot light are again energized. in..the.mann er, as previously described.

Thegapfbetween .the..contacts 3S and;1 40 and between thecontactst and: 50 is soadjusted bybcnding. oI-the

strips

6 and ,88, and the relay coil 20 is so proportioned in respect to its number of turns,- as izo-cause ashing ofthe turn signals and thc-pilot .signall at a predetermined desired rate, tor- -exampler at =the1 rate of .60 `to- '10 times per-minute. lt. will be evident-that :the turn -signet-lights 8B-and being in parallel, the re dstanceinthe turn signal circuit is-relatively small compared tothe-.resistance oieredv by the lowerlcandle-powe'rg-single bulb lpilot light. Hence, --while the-totalement nowingthrough the relay, when the tum-'signals vare energized, Ais suiiicient tooperatlo'n of the relay,the current which would-iiow-through the relay. ii only the pilot light wasenergized, would not be suicient to hold the relay operative.

It will bevide x1t, oi course. that ii the selector swnohgui' is operated to mow the oontooc modo 82 into-engagement with the contact 88., the right turn signal lights H0 and l l2 will be energized ,rathochan-the left-tum signal lights es and 9s.

fas poxiiiod out previousrm che connor; is 1mmoved4 rathenjslowly out of engagement -with' the contact 5B. '"Ihere is, therefore', a tendency tower-@drawing an between the contacts and results iqonstant wear of these contacto d the consequeptiplttlng thereof.

Applicant has discoveredthat if one oi the con tatsismdm ir-'provided with, a surface coating oifsilver-,jad 4tluiother made, or provided afsurfacecoating of tungsten, the drawing, arclng or pitting ofthe contacts may -be mate- -rially'reducedand'the liieoi the contacts in- -crcased'many fold. '.lher eforel it is an important fea'turcoiV applicants inventionthat thejV directly, and -re1ativ`ely\slowly. operating contacts controlled by'the bimet'almernber be'provided with surfacecoatings ofsilver and tungsten.

^ Itis important tonote that thesignal-lights and tbe-pilotlight energized immediately on '-theflclos'ingj'off the selector Bt and Vthus 'insuresmnmediate of thednvers intention-'lto make u tum.' *No period intervenes betweemthe olosingoif theme11; switch and the -energizatlon of theturn signal lights, and thus vthe possibility is eliminated oi accidents c aused by failure to operate the control switch sumfciently innovaties-ofthe initiation ofthe tum. thepilot light to -operate when the .switcbal isoler-edifits-l darkness indicates that thelturnlights controlled by-the switchhave Ybe .comebui'ned out.- lli-.the pilot light flashes at aslower-rate-thamnormal; it indicates -that one ,lightsisburned outrior, -ir. one light is .burned out. tbexesistance in thetum signal circuit in .cteaSl-to approximately twice Vthe value-it the -two.signal.llghts wcre-of equal powerend hence .the,courent:.flowing:tlnzoughlA the blmetal member is reduced to 4one-half f itsnormalvalue and, consequently.. 'amuch greater-time is required ytchcaizfthe 4bimetal-member by that reduced current. :.II the-pilot lightiiashes at a much 'greaterratethan normal, this indicates the existence of a partial short vcircuit in the turn signalcircuit. becausethe increased current which would-flow;.by.reason of such partial short cir- .cuit,=.would causemore rapid heating ofthe bi- -metallic member.. By. partial short circuit, of

course. is meant a short circuit which is established through some element or medium which possesses some resistance, although much less than that of a signal light. Such partial short circuit might be effected, forl example, through a broken iilament in the signal light, or water short circuiting of a wire or light, or by other means commonly experienced in the operation of automobiles or other vehicles.

As shown in Figure 8, the asher 2 may be connected to control a pair of grounded pilot lights, of which there is one for each set of' turn signal lights, thus the terminal 48 may be connected by a wire |24 to one blade |26 ot a double-blade double-throw selector switch |20, having its other blade |30 connected by a wire |32 to the terminal 54. The blade |30 may be provided with contacts |36 and |38, connected by the wires 00 and |04, in the manner previously described, to the left and right sets of turn signal lights. The blade |26 cooperates with poles |40 and |42'connected respectively to right pilot light |44 and left pilot light |46 respectively. It will be evident that upon operation of the master-control or selector switch |28 to selecta particularset of turn signal lights, the corresponding-pilot light will be simultaneously selected for connection to the flasher switch. Hence whentheright turn signal lights and ||2 are operative, thepilot light |44 will also be operative 'and when theleft set of

turn signal lights

96 and 98 is operative, the pilot light |46 will-be operativer As previously descrlbedffthe iiasher rcauses the selected set oi' signal-lights and the corresponding pilot light to ilash in unison'and each pilot light will indicate the-operative condition of its associated set of turnsignal lights. `In some installations, the piiotlight is ungrounded, for one reason or another, which-may involve simply the desire of the auto manufacturers orv the necessities of the electricallsystemvohthe particular make or model o1' the-automobile.4 The flasher 2 may be connected in a slngleungrounded pilot light system, as shown in Figure 9,- ol-in a double ungrounded pilot-light system asshown in Figure l0. l y.

As shown in Figure 9, the ungrounded: pilot light |48 may be connected oni one sidelfasgby wire |50, to the terminal-4B of-thef-issherpand the opposite side of the-pilot-lightf-is (connected, as by wire |52, to the wire 80-which extends-from the terminal 54 Voi? the;-iiasher to theanovable blade 82 of the selector switch=04.'--'=-when 'the selector switch is closed to energizeoneor the other set of turn signallightsfcontacts fand 50, controlled by the .birnetall member? being closed, the pilot light |40 willbe short-Tcircuited through a short circuit extending fmmthe trminal 48 through the contacts 40and-l6and`fthe switch blade 23 to cross-arm 26ofitli'e1core m'ember I4, the bimetal memberf, contactsal'and 50, the terminal 54,1the, wire-00landf th'e wire |52. The pilot light |40 is of such'resistncethat the current owing through theirelay whnfthe bimetal contacts are open, is suillcient to maintain the switch blade 28 in its lower position, in which the

contacts

36 and 40 are'heid'inengagement. The resistance of` thislpilot lightiisf-i'iowever, greater than the resistance of the bimetllic strip and, hence, when the cont'acts''ahd 50 are disengaged, the current of the signal lights is reduced, It will be evident, therefore, that i1 the pilot light |48 fails to light,'it'indicate`s`that both of the lights of the selected'set of'tllrn 'sig- Anal lights are Yhurried out. "If the'pilot lightremains on longer than the usual periods, it indicates a partial short circuit in the circuit of the selected lights; whereas, if it remains off longer periods than normal, it indicates that one of the lights of the selected set of turn signal lights is burned out. The

contacts

36 and 40, controlled by the switch blade 28, are accordingly held closed whenever the selector switch is operated to energize-the turn signal lights, and are open only when the selector switch is open The switch composedof the

contacts

36 and 40 therefore serves to prevent sneak circulating currents.

contacts

38 and 50, controlled by the bimetallic member, are closed. but will be connected in series with its associated set of turn signal lights when these contacts are open. The operation of this circuit will be evident from the disclosure of the operation of Figure 9, each pilot light serving in the same manner to indicate the operative condition of its associated set of turn signal lights. The switch composed of the

contacts

36 and 40, operated b y the switch blade 28, serves also in this circuit to insure against sneak currents and also the operation of the asher by ground establishing faults inthe pilot circuit.

In some installations it is,.for various reasons, necessary or desirable that the pilot light be in series with the selected set of turn signal lights. As shown in Figure 11-, the flasher 2 may be lncorporated in such a circuit by connecting the terminal 54 by wire |68 to one side of the pilot light |10, which is connected at its other side by wire |12 to the movable blade 82 of the singlepole, double-throw selector switch 84. In such a circuit the pilot lig-ht |10 is of sufilciently low resistance as to permit the ilow of enough current to energize the turn signal lights, notwithstanding thefact that the pilot light is connected in series therewith. It willbe evident, of course, that pilot light |10 flashes simultaneously with the turny signal lights and that a ground establlshing fault on the pilot circuit, if suillcient to cause an appreciable sneak current, will light the pilot when the switch 04 is open. If the pilot light fails `to light when the' switch 84 is closed, it indicates that both lights of the seiected set 'of turn signal lights are burned out. If the pilot ylight ilashes at a slow speed, it indicates that one light of the selected set of turn signal lights is burned out, and if it flashes at a higher speed than nunmal, it will indicate the existence of a partial short circuit in the selected set of turnslgnallights.

In some installations, for various reasons, it is necessary or desirable that double-grounded pilot lights be operated in direct parallel with turn signal lights. In such an installation, the flasher may be connected as shown in Figure 12, in which the right and left pilot lights |14 and |16, respectively, are connected directly by wires |18 and to the wires |04 and 90, respectively. The terminal 54 of the flasher is connected directly to the movable switch blade 62 of the selector switch 84, as by the wire 80, similar to the circuit of Figure 7.' The resistance between the wire 90,

orthe wire |84, and. the grounded side of the source, may be less than the total resistance between these wires and ground in the circuit oi Figure 7. This will, of course, cause operation of the flasher at a higher rate. course, be unobjectionable if the rate of flashing does not exceed the persistence of vision,

which is extremely unlikely. However, if the rate of flashing should be objectionably rapid,

it may be compensated by the interpositlon of a small resistor |82 in the lead 88.

The ilasher may also be connected to cause automatic flashing of a stop signal light whenever the brakes are applied and, independently of the tum signal lights, while lcausing simultaneons dashing of the stop light with the turn signal lights, should thebrakes be applied in approaching or making the turn. Such may be accomplished by the circuits shown in Figure 13, in which the terminal 54 of the flasher is connected in parallel by -wires |84 and |86 to the movable blade 82 of the manual selector switch 84 and the brake controlled switch |88t The brakecontrolled switch |88 is connected. as by the wire |88, tothe ungrounded side of the stop signallight |92.' Whenever the brake controlled switchV I 88 is closed, the circuit will be completed from the battery or source T4 through wires 12, terminal 58, relay coil 28; core-member I4 and bimetal member 38,

contacts

38 and 58, terminal 54, wire |86,`switch |88 and wire |88 to the stop signal -iight |192. This circuit is, ofcourse, lndependent of the selector switch 84 and, consequently, whenever the brakes are applled,the flasher is set into operation to' cause the stop signal light to flash and the pilot light |28` to flash simultaneously therewith, but if the brakes be applied when approaching or making a turn, during which time the selector switch is'closed, then'the contacts 38 'and 58 will-controlboth thesignal light and the stop light circuits andf cause the lights to liash simultaneously.

Since the 4resistance to the passage yof' current through the bimetallic memberV is normallygreater when the stop light alone is operated; 45

than when' the turn signals are operated; and the resistance to the flow of such current is less'` when' the stop and turn signals are flashed simultaneously, itfollows that the stoplight, whenv operated alone, slow rate, which is desirable when the 'auto is slowing down in a line of trame or 'to a stop'on` the road.` The increase in'ashing ratewhen theV stop' and turn signalsv are simultaneously operated will not ordinarily-be obiectionable:-, Iny those cases in which the increased flashing rate, under such circumstances.- may be obiectionable, the circuit shown in Figure 14 maybe employed, As shown in this iig-ure, rthe lterminal 48 'may be connected in parallel to the pilot light |28 and stop-light |92 by meansofwire |84 and wire |88, leading tc the blade |98 oi a double-pole, singlethrow brake control switch 288. The blade- |98 controls the circuit to the stop light, while the companion blade 282 oi this switch controls the circuit of a stop pilot light 284. The nxed contact, cooperating with the blade 282, may be connected as by wire 288 to the ungrounded side of the pilot light 284, while the blade 282 is connected by wire 288 to the contact 2|8 of a singlewill be flashed at a'relatively 50.-

pole selector switch 2-I2, having addition-al contacts 2|4 and 2||6 connected, respectively, to the left and to the right sets of turn signal lights in the manner previously described. The switch 2|2 constitutes a turn signal selector switch simi- `maybe 'turned to an open position. In the case of l0 f lar to the switch 84, but provided with the third contact 2 8 so positioned' that the moveableblade engages that contact when in normal neutral position. The signal switch 2|2 being in normal This wm, of 5 neutral position, the pilot lightA 2M will be connected in series with the bimetallic member v38 and the relay coil 28 when the brake controlled switch 288 is closed. TheV current flow through this circuit causes operation ot the liasher-the

vswitch contacts

36 and 48 controlled-by the switch blade .2-8opening andclosing simultaneously or substantially simultaneously with theopening and closing of the contacts 38 and 58: Hencel the pilot light 284 and the stop light |92 -will Yflash simultaneously at a rate determined by the resistance of the-pilot light 284, which may, of course, be such to give the desired dashing rate for the stop light when operated alone. It may, if desired, be a pilot light of such p ower that its resistance is equal to one-half the resistance of each turn. signal lightand,` hence, equal to the parallel resistance of the turn lights, so -that the flashing rate of the stop light 4when used alone will be the same as the flashing rate determined by the tum signal lights.

When the selector switch 2 I2 is 4moved to operate a selected set of turn signal lights, the connection is broken between the contact 2|8 and Ythe blade of the selector switch and, hence, the

circuit to the pilot light 284 will not be completed by operation of the brake controlled switchv 288.

However, ii the brake is'operated while the turnV signal iight is energized, thestoplight |92 will be energized andiiashed by the opening and closing of the cotactsi and 48 simultaneously withV the turnv signal lights and -the pilot light" |28.` Thus increase inthe flashing rate, due to application of the brakes while the turn signal is energized, is prevented.

The pilot light 284 t-hus: serves Iboth the double functions of indicating the operative condition `of the stop light circuit when-operated independently oi.' theturn signallighta-and determines the rateof 'dashing of the stop signal.- when operated alone. Since the-resistance to the flowof current through 'the relay andg'the pllotfcircuit is less in thecircuit oflfligure le than-in-other figures, as, for example, Figure 7, lamps of greater resistance must be used to prevent holdingof the relay;l orthe gap between the contacts SI5-and 48-must be widened, as by upward bending ofthe strips 66 and 28. so as to require a'greater force of attraction to hold the contacts closed.-

For various reasons, in some installations, it

stituting in the circuit of- Figure 8, pilot lights of suilloiently low resistance to allow the passage of enough current to hold the relay operative once the switch blade 28 has been operatedfollowing the closure of the selector switch |28. InV such case, the switch contacts 3G and 48 controlled by the blade 28 will remain closed during the successive opening and closing of the switch controlled bythe bimetal member. Hence the turn signal lightswill be flashed but the selected pilot light will remain on continuously so long as the turn signal lights are being flashed and will become deenerg'ized only when the selector switch is redouble desirable or required that a single groundlight serve toindicate whether the turn ungrounded -pilot lights, this may be accomplished by connecting the 4wire |66 in the circuit of Figure directly to ground rather than to the blade |30.

In the case oi a single grounded pilot light, the circuit of Figure may lie-employed. As shown in this circuit,l the terminal 4831s connected by a wire vv2|8 to the blade 220 of a double-pole, doublethrow selector switch 222.

Contacts

224 and 226, which cooperate 4with the blade 220, are connected in parallel toone side of the grounded pilot light 228.- The terminal 54 is connected, as by wire 2 30, to the other'blade 232 oi the selector swltch,'which has contacts connected, as previously described, to the -leit and right sets of turn signal lightsthe pilot light 228 being of sufficiently imi'l resistance to allow the iiow of enough currentto hold the relay operative. Once the selector switch has been closed, the pilot light will remain on continuously during the operation of the turn signal lights, but will be extinguished upon the opening of 'the selector switch. If the selected set ofturn signal lights is inoperative cnous-'h current will not Viilow through the relay and the bimetal member to attract the blade 28 to switch-closing position and, hence, the pilot light will remain oli. It will be evident, from Figure 1,5.- that in the-caseot a single ungrounded pilot light, the pilot light may be interposed in the wire 2|||Y and the contacts 224 and 22B directly grounded. A, l

Insome cases itis desirable, or the ,installationl may besuch as to require. that `thepilotlight dash alternately with respect to the turn signal lights. For such 13111110 thecontact carrying bracket 42 maybereplaced by a bracket 234, Fig. 16, which extends outside the cross-bar' 22 of the core member and over the armature 32. The amature 32 now carries on its uppersurface thecontact 23H8 which cooperateswith the con-g tact 238d epending'i'romthe overhanging portion of the bracket `234 ;'The'b1jacket 2341s secured ofthe same structureas-tlie bracket Q;andcarl' rylng the terminal; 242, For controllingM single-crumble ungrounded Y:pilot flights'., this 45 thel reference nu shownA in, Figuresr' and 256, respectively, connected on their other side by wires 258 and 260 to contacts |42 and |40, respectively, of the double-pole, double-throw selector switch |28, having electrically interconnected bladesl The operation of this circuit will be evident from the description of the operation of the circuit of Figure 17.

As shown in Figure 19, a single grounded pilot light may be controlled by the flasher 2 by connecting the ungrounded side of the pilot light 262 in parallel to the

contacts

224 and 226 of the selector switch 222. The blade 220 of this switch is connected by wire 264 to the terminal 242 of the ilasher 2'. It will be evident that upon closure of the selector switch, contacts 236 and 23B will be opened by the consequent energization of. the relay, but will be closed when the bimetallic contacts are opened and, hence, the pilot light will iiash alternately with respect to the turn signal lights. It should be noted that. with this circuit, the pilot light will light immediately on the closing of the selector switch if the lights oi the selected set of turn signal lights are burned out; whereas, in the circuit of Figure 17, the pilot light will remain out if the turn signal lights are burned out. Since, in the normal operation of the circuit of Figure' 1'?, the pilot light does not light immediately on the closing of the selector switch, its continued failure to light, by reason of the 'burning out of the turn signal lights, may not be noted. Therefore, it maybe preferable to so connect the ungrounded pilot light that on burning out of theturn signal lights, the pilot light lights up immediately on the closing of the selector switch. This may be accomplished, as will be evident. by interposingthe ungrounded pilot light in thewire 264 of the circuit of Figure 19 if the contacts 224 and' 226 of the selector switehiare directly-'grounded A As shown -in Figure 20, the terminal 242 of the ilasher 2' is connected -bywire 2564to the blade 220 ot the double-pole, double-throw selector switch-222, while the left andy right pilot lights 268 and=-210 arerconnected respectively to the

contacts

226 and 224 ofthis selector switch. The operation of thiscircuit-willbe evidenti from the description'oi the operation ofthe circuit of Figure 19.'E fIt should be -notedthatthe selected pilot light will--lightfxslmultaneously with the closure oif'theselector switch-and remain lit if the turn is am in asumir,- as s a m naar need to one ede-effe@ @message uit. 244 by a 246A, the other side of the pilot light being connected vby a` f-wire 248'toythe wire 80 signal lights of thecorresponding set are burned outfwhereas, inrespect to the circuit of Figure lftheselected pilotlight will remain out it the corresponding set of turn signal lights is burned which extends m me maussade ef'tes'itf fibuti AS Pointed but hefeiOfOreit may be desirswi-tch 64, Ithe selector beingf c1cs`ed to ener? gize the selected `set of turn signal lights. 'I 'he relay. in attracting the armature'22.- causes disengagementof-the contactant and `23". Hence.

thatthe contacts 3B and-50 are in engagement.

The contacts 236 and'238 will 'automatically close when the relay is deenergized and, hence, when the bimetallfic strip, on heating, opens its contacts, the pilot light is energized and rwhen the bimetallic member, on cooling, closes its contacts, the pilot light is deenerglzed.

If both lights of the selected set of signal lights are burned out, the

contacts

236 and 238 will remain in engagement on closing of the selector switch. -but the pilot light will not light because no circuit will be completed to ground.

As shown in Figure 18, the terminal 242 is connected by wires 25|)` and 252mV parallel to one side of the left and right ungounded pilot lights 254 able to provide, in the case of double ungrounded pilot lights, that the pilot lights go on ii the turn signal lights -oi'lthe corresponding sets are burned out. This may be accomplished by elimihating the connection |66 between the blades ci the selector switch |26 of 'Figure 18 and connecting the blade |26 directly to ground.

It willbe evident that in the circuits of Figures 17 and 18, the'turn signal lights will be ilashed by being periodically dimmed by the insertion of the additional resistance represented by the pilot light, whereas in the circuits of Figures 19 and 20, the pilot lights will be ilashed by being periodically cut off. This flashing of the lights by dimming rather than by cutting ol is also true of the circuit of Figure 9. Since certain advantages are inherent in the dashing of lights by dimming rather than cutting oli, these circuits may, in some cases, be preferred.

Although the use of contacts, one of which has a silver surface and the -otheroi which has a tungsten surface minimizes pitting and, thereiore, prolongs the liie of the contacts, it does not eliminate such-pitting and;- 'in those installations where the additional expense may be justied, the further improved flasher 2" of Figures 21 to 25 may be provided.' As vshown in these figures, the bimetallic member 30 is secured at its-outer free end to a contact carrying strip 212 'and this contact'carrier isV connected to a small armature piece 214 by -a resilient phosphor bronze strip 216.4 The contact carrier 212 carries theV contact 38 which,` as before, cooperates' with contact, 5o carried by the bracket 52. Thearmature'zfld carries an addltionalconta 216 at-its outer'fre'e endand this contact cooperates with a contact 280 carried by an upwardlyand outwardly struck portion of lug 282 of the bracket-*52: This flasher may be connected in the circuits of Figures '7 to 15 in the same manner as the flasher 2, and may be connected in the circuits of Figures 1'? to 20 if the bracket 62, supporting the contact 40, is replaced by the bracket 234 carrying the contact 236, as indicated in Figure 16, and the contact carried by the amature 32 extended above the armature. as indicated in Figure 16. This is exempliiied by the schemetic circuit diagram, Figure 26, in which the terminal 64 is connected internally of the flasher by the bracket 52 to the

contacts

50 and 280. The terminal 54 is connected by a wire 284, corresponding to the wire 8 (Figure '1) to the blade 82 oi the same selector switch 84, while the terminal 48 is connected by a wire 286. corresponding to the wire I I8, to the pilot light |28, which is grounded as at |22. With the selector switch in open position, as indicated in Figure 24, the contact sa is heldin engagement withthe contact l) by the bimetal member 30, but the contact 21B-is -held by the spring action of the spring 218 out of engagement with the contact 280, as indicatedin Figure 22. When the selector switch is closed to energize the selected set of turn signal lights. the circuit to the signal lights isinstantaneously completed through the closed contacts 38 and 60 and the consequent energization o! the relay results, in the. downward attraction of the armature 211i so as to close the

contacts

218 and 280, as indicated in Figure 23. As the bimetal member, on heating, moves the contact 38 out or engagement with the contact 50 and to the position as indicated in Figure 24, the contact 218 remains in engagement with the contact 28B by virture ot the magnetic action of the relay on the armature 218, the relay and turn signal circuit remaining completed through the contacts 218 and 288 in spite o! the opening of the

contacts

38 and 58. The current still :lows through the bimetal member and, hence, as it heats up reaches such a position that the force exerted on the armature through the resilient strip 216 exceeds the magnetic holding force o the relay and the contact 218, by virtue oi' the spring action of the strip 216, springs or snaps out of engage ment with the contact 286. The circuit to the relay is then broken and at the same time the turn signal lights are deenerglzed. The pilot light is simultaneously deenergized by the opening of the

contacts

36 and 40, as previously described with reference to the ilasher 2. As the bimetallic member pulls down, it first reaches the position shown in Figure 22, in which contacts 33 and 50 are brought into engagement and, as soon as this is accomplished. the consequentI energization of the relay snaps the contact 218 and'il and, thusreduces lli into engagementwiththecoritact 280'. The closing of Ithese 'contacts 218 'and 280 establishes the relayfcircit independently of the bimetal con tact's and prevents fluttering oi the contacts 38 the pitting possibilities. Since at the time the

contacts

38 and 50 are separated-on the heating'of the bimetallic member -the'

contacts

218 and 280 are still closed, no arc willbe'drawn'be'tweenthe contacts 38 and 5d as they are slowly m'oved'apart by the bimetal member. Since' the

contacts

218 and 280 are moved Aapart by`-'the'sudden spring' action of the strip 216 'rather than-by the slo'w movement of the bimetallic member, the pitting of these contacts is prevented.

the other so far as the maintenance of the operation of the circuits is concerned. Y

It win be frther evident' that the modificano disclosed in Figure 16 may equally be considered to apply to the ilasher 2", and that the asher 2". when so modified, may be connected in the same external circuits as the flasher 2'.

It will be evident, therefore, that applicant has provided a universal vehicle or auto signal asher switch which is capable of incorporation in all, or substantially all, automobile or vehicle lamp signal flasher systems. and that such device is rugged in construction, inexpensive to manufacture. certain in operation and relatively low in cost. It is also evident that applicant has provided certain novel and useful circuits inter-relating the turn signal lights, pilot lightsand also inter-relating these with the stop signals; and has provided a flasher which replaces and largely makes unnecessary the manufacture and stocking of a number of diiierent models for such circuit installations.

While certain specific structural details have been disclosed and described herein for the purpose of illustrating certain embodiments of my invention, it will be apparent that other modifications and changes may be made without departing from the spirit and scope of the appended claims.

What I claim is:

1. In a flasher switch, an electromagnet, a bimetallic member in series with said electromagnet, a nrst switch including a contact carried by said bimetallic member, said rst switch being in more and more, it finally series with said bimetallic member and said electromagnet. an armature for said electromagnet, a second switch including a contact carried by said armature and electrically connected in parallel with said ilrst switch.

2. Afflasher switch comprising an electromagnet, an armature for said electromagnet, a bimetalmember flxed at one end thereof and electrically connected in series with said electromagnet, a resilient member secured at one end thereof to the other end of said bimetal member. said resilient member on its other end supporting said armature in the magnetic neld of said electromagnet for attraction thereto on energization thereof, a pair of movable contacts, one of said movable contacts being carried on said other end of the bimetal member and electrically connected thereto, the other of said movable contacts being carried by said armature and electrically connected to said one movable contact, a pair of xed contacts respectively disposed for engagement by said movable contacts, said resilient member being constructed and arranged and yieldable to permit separation of the contact carried by the bimetal member from its cooperating fixed contact during the heating of the bimetai member and prior to the separation of the other movable contact from its cooperating fixed contact, and a pair of terminals adapted to be connected to a source of supply and to a load, one of said terminals being connected to one end of said electromagnet, the other of said terminals being connected in parallel to said xed contacts whereby the circuit through said terminals is broken by movement of the movable contact carried by the resilient member away from its cooperative xed contact and is completed by engagement of the movable contact carried by the bimetal member with its cooperating xed contact.

HENRY R. GROSS.

REFERENCES CITED The following references are of record in the tile of this patent:

Number UNITED STATES PATENTS Name Date Levengood Aug. 2, 1910 f Lindquist July 11, 1916 Taylor July 10, 1917 Reed Oct. 7, 1919 Van Guilder May 18, 1926 Phelps June 5, 1928 Axelberg June 25, 1935 True July 7, 1936 Schmidinger Dec. 28, 1937 Trautner May 31, 1938 Chase Aug. 2, 1938 Doane Oct. 14, 1941 Werner Oct. 20, 1942 Hosmer Nov. 3, 1942 Falge et al June 15, 1943