US2318700A - Combined incandescent lamp and flasher switch - Google Patents

Description

I. E. M CABE Mny 11, 1943.

COMBINED INCANDESCENT LAMP AND FLASHER SWITCH Filed April 27, 1942 2 Sheets-Sheet l lllllll C ATTORNEY.

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Bl-METAL u 943. I. 5.. M CABE 2,318,700

COMBINED INCANDESCENT- LAMP FLASHER SWITCH Filed April 27, 1942 2 Sheets-Sheet 2 BY M ATTORNEY.

Patented May 11, 1943 UNITED STATES PATENT OFFICE v z,s1s.'m comm mcmasoam' mm m mam swrrcn Ira s. McOabe, calm. in. Application April 21. ms, serial No. 440,004

4 Chime. (01. 110-24) This invention relates to improvements in combined incandescent lamp and flasher switches used as signals or markers ior air ports, harbors. street intersections or where needed as location, warning or directional indicators Devices oi this kind now in use generally employ the commercial incandescent electric lamp with various iorms oi electrically actuated switch mechanisms to cause the lamp to be intermittently energized to produce a flashing eflect. Such lamp flashing mechanisms require skilled servicing when out oi order. As it is customary in most lamp flashers of this character to employ batteries as the source oi electricity for both the lamp and the flashing mechanism. the use oi such flashing mechanism shortens the hi oi the battery and, therefore, req ir s the employment of a large number oi standard size batteries or an extra large size battery to prevent irequent battery replacement.

It is an object oi this invention to provide an incandescent electric lamp bulb which also contains a flasher switch mechanism responsive to the heat from the incandescent fllament to automatically and continuously open and close the electric circuit through the lamp as long as the lamp itconnected in circuit with the source oi electricity.

It is another object oi this invention to provide an incandescent electric lamp which when connected in circuit with the source oi electricity will become incandescent to not only act as a source oi light or visual signal. but the heat generated by the fllament when incandescent will act upon a bi-metallic thermal switch member to break the circuit to the fllament. The bi-metallic thermal member then cools and re-establishes the circuit so that the lamp will automatically create continuous flashes oi light.

It is a iurther obiect .oi this invention to provide within the lamp bulb a pool oi mercury connected to one side oi the lamp circuit, the other side oi which is connected to one end oi the lamp upon the heat responsive member to withdraw the free end oi the member irom the pool oi mercury to break the circuit through the lamp fllament.

The advantages oi such a construction are obvious. The source oi light andthe flashing mechanism are all contained within the lamp bulb. It

needs no skilled servicing because when a fllament has burned out'or the flashing mechanism has been damaged and becomes inoperative, it only requires removing the dead bulb and puttinginanewoner'lheinitialcostoithisimproved combined lamp and flasher switch is considerable less than the cost oi a commercial lamp and separate flasher mechanism. It is also more economical to operate.

With these and other objects in view, reierence is made to the accompanying sheets oi drawings which illustrate preferred iorms 'oi this invention with the understanding that detailed changes may be made without departing irom the scope thereoi.

In the drawings:

Figure l is a view in elevation of a iorm of this improved combined lamp and flasher switch shown supported in a preierable iorm oi mounting with parts oi the bulb broken away to show the flasher mechanism- Figure 2 is a detail view in elevation 0! another iorm of this invention with the bulb shown in section.

Figure 3 is a similar view oi another iorm of this invention with a part oi the bulb broken away to show the flasher mechanism.

Figure 4 is a view in vertical section taken cen- I trally through still another iorm of this invention in which the bulb is inverted.

Figure 5 is a view in elevation oi a standard or i rangement providing for the alternate flashing oi two lamp fllaments.

Figure 7 is a view in vertical section taken centrally through still another iorm oi this invention and its application in a circuit arrangement which provides for the flashing to be continued by emergency lamps in the event a fllament burns out in the flrst lamp.

In the embodiment oi this invention illustrated in Figure l, the neck or closed end I oi the bulb I is inserted in a sleeve 3 preierably secured thereto by cement. The upper end oi the sleeve 3 is supported in a particular iorm oi bracket 4 such as disclosed in the applicant's prior Patent No. 2.311.361. oi September 5, 1939, and therefore no detailed description beyond possib the statement that the leading inwires 6 s id I through the upper sealed end oi the bulb 2 are connected by lead wires to contact members forming a part of the bracket 8.

As seen in this view, the axis of the bulb lies in a vertical plane and the bulb proper is provided with a depending cup I in the lower end thereof which contains a pool of mercury 8. The leading in wire 5 is continuedthrough the closed sealed end of the bulb to extend into the cup I and be submerged in the mercury 8. A glass bead 9 connects the leading in wires 5 and 6 within the bulb 2 and the leading in wire 6 is connected to one end of an incandescent filament ill, the other end of which is connected to and supported upon the lower end of an electrical conductor H, the upper end of which is supported in the glass bead 9 preferably between and separated from the leading in wires 5 and 6. A strip of bi-metallic metal l2 responsive to changes in temperature is mounted in spaced relation below the filament Ill and above the upper surface of the mercury 8. The upper end of the bimetallic thermal member I2 is secured to the lower end of a conductor wire 13, the upper end of which is mounted upon the filament support H. The lower end of the thermal member I 2 is provided with a contact member l4 so arranged that when the circuit through the lamp is open and the filament l cold, the thermal member IE will cause its contact member I4 to engage and be submerged in the mercury 8. With the parts in this position, and the bulb connected to a source of electricity, a circuit will be established through the filament to bring it to incandescence to create a source of light and at the same time, the heat from the incandescent filament will act upon the thermally responsive strip I 2 to cause it to deform and withdraw the contact member M from the pool of mercury which will break the circuit through the lamp and allow the filament ill to cool. The cooling of the filament again causes the establishment of the electric circuit through the lamp when the contact member I4 engages the pool of mercury 8. This cycle will continue as long as the bulb is connected in circuit with the source 'of electricity and will therefore produce intermittent flashes of the lamp.

The Patent No. 2,171,861 previously referred to as disclosing the form of support 3 and bracket 4 shown in Figure 1, provides for the rotatable adjustment of the sleeve 3 by an adjusting screw 20. This feature may be utilized in connection with this invention when it is desired to direct the flashes of light in particular directions, in which case the bulb 2 can have a portion. of its surface silvered or provided with a reflector and the adjusting screw 20 then used to position the lamp so that the light flashes will be reflected in a particular direction.

Figure 2 illustrates the application of this invention to an electric lamp in which the sealed end of the bulb i5 is contained in the customary lamp base l6 provided with the usual bayonet projections H for engagement with a bayonet slotted lamp socket not shown. In this type of lamp, the leading in wires 5 and 6 pass through the base and are connected to contacts 5 and 6 upon the exterior of the base. The filament I0 is supported by an electrical conductor H in the same manner as in Figure 1 and the bimetallic strip I2 is carried on this supported by a conductor wire E3 in the same manner. In this type, the bimetallic strip 12- is curved at its upper end as shown with the center of curvature adjacent the filament 10 which renders it more sensitive than the flat strip [2 in Figure 1. The free end of the thermal strip 12 is provided with a contact piece Id the end of which will be submerged in the mercury 8 in the mercury cup 1 in the bottom of the bulb when the filament is cold and when the filament is energized, the heat generated as it becomes incandescent causes the free end of the thermal strip l2 to move outwardly and withdraw the contact M from the mercury.

In Figures 1 and 2, the flashing mechanism is arranged for a lamp construction in which the axis of the lamp is mounted in a vertical position with the pool of mercury supported in a well aligned with the axis and extending below the bottom of the bulb. It may be desirable to provides, lamp for mounting with the axis of the lamp in a horizontal position, such as shown in Figure 3. In this type, the depending well l is formed in the side of the bulb I5, the sealed end of which is received in a lamp base Hi and the leading in wires 5 and 6 are connected to the lamp contacts 5 and 6. In this form, the leading in wire 5 is preferably arranged below the leading in wire 6 and the end enters the mercury 8 in the well 1. One end of the filament 10 is connected to the extremity of the leading in wire 6 and the other end to the support li supported and held intermediate the leading in wires by the glass bead 9?. In this form, the strip of thermal metal l2 is preferably fluted or corrugated as shown with its axis lying in a horizontal plane. One end is connected to -the support H by the bracket l3 and the free end is provided with a contact 14. The thermal strip is so arranged that when the circuit is broken through the switch and the thermal strip is cold, the contact M will be submergedin the pool of mercury 8 so that when the circuit is established, the filament ID will become incandescent and the heat therefrom will cause the thermal strip 12' to deform and move the'contact M out of the mercury 8 and break the circuit therethrough.

At times it may be desirable to construct a combined lamp and filament mechanism whereby the axis of the lamp will be in a vertical plane with the sealed end of the bulb extending below the bulb proper, as shown in Figure 4. In such a construction, the sealed end of the bulb I5 is mounted in the lamp base 5 and the sealed end recessed as at 7 to form a cup to contain the.

pool of mercury 8. The leading in wire 5 extends through the sealed end of the bulb and through the pool of mercury 8 to adjacent the upper end of the bulb l5 where'it supports one end of a glass bead 9. The leading in wire l passes through a glass tube l8 extending up-- wardly from the sealed end of the bulb to a point above the upper surface of the mercury 8, the wire 6 extending therebeyond to support the glass bead 9, passing downwardly through the,

bead to provide a support and connection for one end of the filament l0. The filament l0 is connected to this extremity of the leading in wire 8 and at the other end to the support the latter spaced apart from the wires 5 and 6 and depending from the glass bead 9. The bi-metallic strip l2 is preferably of the same curved formation as shown in Figure 2 and is connected to the filament support l| by the bracket l3. The free end of the bi-metallic strip |2 is provided with a contact 14 and the parts are so arranged that when the circuit is broken through the lamp, the bi-metallic strip l2 will normally hold the contact II= submerged in the mercury I and when the circuit is established through the switch, the fllament II will become incandescent and the heat generated thereby will deform the thermal strip I2 to withdraw the contact II' 4 from the mercury to break the circuit. The fllament will then be-deenergined and upon cooling, the thermal strip I2 will again bring the contact W in engagement with the mercury I.

Should the iorm .shown in Figure 4 be desired operated irom an elevated position irom where it is desired that the lamp flashing be visible only from above the lower portion of the bulb I! can be blackened or part oi the bulb suriace ailvered to not only obscure the flashing from below, but to accentuateand concentrate the light flashes upwardly.

Figure 5 illustrates a commercial form oi a warning or highway intersectional tramc signal II, for supporting a reflector 2I upon a rotatable bracket 2i; in which this combined lamp and flasher may be advantageously employed.

Figure 6 illustrates the application oi another form of this invention. wherein the alternate flashing of two lamp filaments may be accomplished. such as is oiten used at railroad crossings.

In this form the combined lamp and flasher 2' takes the tom of that shown in Figure l, corresponding parts being identified by like reierence numbers, with the addition thereto or another contact member. A third leading in wire 22 is sealed in the upper sealed end of the bulb 2. extending therethrough into the bulb below and passing through the glass head I, where it terminates a short distance beyond to provide a subport for a flexible wire electrode II. The flexible wire 2I terminates in a contact II which when the lamp is not flashing assumes a position spaced but adjacent to the well oi mercury I.-

Intermediate its length the flexible -wire II is iormed to extend across the path oi movement made by the thermal member I2 when heated and insulated irom electrical contact therewith thermal member I2 cools iollowing the opening oi the fllament circuit through contact II and mercury I the contact II is restored into engagement with the mercury while the flexible wire II moves the contact 24 out of the mercury.

To provide ior alternate lamp flashing the wire I isconnectedtooneaideoiabatteryorother source oi electrical energy 3 in which circuit may be interposed a hand or automatic switch 8. which can be used todetermine the time when the lamps are to operate. The opposite side oi thebatteryBisconnectedbyawireIItothelead in wire I'oi lamp 2, thus completing a circuit to thefllament ilwhentheswitchsisclosedand the contact member II is immersed in the mercuryI. Theotherlamptobeflashedcomprises a commercial iorm oi lamp L having a fllament II therespective ends oi which are connected toexternalcontactterminalsflandil. Terminalllisconnectedbyawirefltoleadinwirefl oilampbwhileterminalflisconnectedbywire IItowireIIleadinatothebatteryB.

when-theswitchsisopennocurrentflowsto eitherlampandthecontacts llandIIoilamp ing switch 8 the circuit through the filament II of lamp 2' will be made but the circuit through the fllament II oi lamp L is open since contact 24 oi lamp 2 is out oi contact with the mercury I. As the filament II becomes incandescent and heats the thermal member I2. contact II will be withdrawn irom the mercury and contact 24 immersed therein. The circuit through the filament II will be broken, but the circuit to fllament II or lamp L established as contact 24 engages mercury I. The filament II then will become incandescent and remain so until the thermal member I2 oi lamp 2 cools, whereupon contact 24 is withdrawn from the mercury to open the circuit to fllament II and the contact it returned into en agement with the mercury to reestablish the circuit through filament II. As long as the switch 8 remains closed there will occur alternate flashings oi the filaments -II and II with the filament II being incandescent during the heating of the thermal member I2 and the filament II beingincandescent during the cooling period of member I2.

Figure 7 illustrates another form of this invention by means of which additional or emergency flashing lamps may be automatically placed in operation to replace those in which the fllament has burned out so as to insure the constant operation oi a signal throughout a desired period.

In this form the combined lamp and flashers.

2" and 2 are shown as again taking the iorm oi l'lgure l in which like parts are given like reference numbers and to which has been added an additional bi-metallic thermal member ior operating an additional contact. Referring to the lamps 2' and 2 a third lead in wire II is sealed into the neck of the lamp with the wires I and I, terminating within the bulb after passing through the glass head I a short distance above the fllament II. Secured to the inner free end of wire II is one end of a fluted or corrugated bl-metallic thermal member I2 arranged above and close to the filament II. The iree end of the thermal member II has secured thereto a wire II which terminates in a contact II engaging the mercury I when the thermal member II is cold.

The thermal member I2 is of such a form that when the fllament II becomes incandescent the member I2 will respond to the heat from the fllament at a faster rate than will the thermal member I2. Thus the contact II will he removed from engagement with the mercury beiore the thermal member l2 has been sufllciently heated to .cause the removal oi contact II from the mercury. With a greater degree oi movement being imparted to the thermal member I2 2' will assume the'positions shown. Upon olosthan to the thermal member I2 when the fllament is energized the opening and closing of the fllament circuit by the thermal member I2, as long as the supply oi electricity continues, will occur with the thermal member I2 maintaining contact II out 0! engagement with the mercury. Contact II can thus be utilized to control a circuit to an additional lamp which will be completed when the-fllament burns out or is otherwise damaged so as to break the filament circuit whereaiter the thermal member I2 cools to establish engagement of the contact II with the mercury.

As shown in Figure 7 two lamps 2 and 2 oi the same kind are shown in a circuit arrangement which includes a lamp 2' oi the type illustrated in Figure 1. Lamp 2" is connected irom 38, respectively, with lead in wire 3| connected by wire 33 to lead in wire5 of lamp. 2. Lamp A 2 has its lead in wirev 6 connected to wire 36 by wire 40 and lead in wire 3| by wire 4| to terminal 3 of lamp 2 Lamp 2 has its other terminal 5 connected by wire 42 to wire 36 from the source of electricity.

With electricity available a circuit will be established over wires 35 and 31 to lead in wire 5 to energize the filament ID of lamp 2 from whence it continues through lead in wire 6 to the other side of the supply line 36. At this time contact 34 is in engagement with the mercury 8 so that a circuit is also established from this point through the thermal member 32, lead in wire 3| and over wire 39 to lead in wire 5 of lamp 2 which then energizes filament ID of that lamp as well as completing still another circuit through the mercury and contact 34 and lead in wire 3| of lamp 2 over wire 4| to lamp 2 through which the last named circuit is completed over wire 42 to the electric supply wire 33 so that filament ll! of lamp 2 also becomes energized. However thecircuits to lamps 2 arid 2 will remain closed for only a short period, for in that time the filament III of lamp 2 will heat the thermal member 32, therein causing the contact 34 connected thereto to be moved out of engagement with the mercury 8, thus opening the circuit to lamps 2 and 2 As previously described, the operation of the thermal member 32 will remove the contact 34 from engagement with the mercury in much less time than the thermal member l2 will respond to the heat from the filament Hi to remove its contact from engagement with the mercury. With the lamp 2 remaining in circuit with the source of electricity the filament I3 therein will intermittently flash as the thermal member l2 makes and breaks contact with the mercury upon heating and cooling. During this time the thermal member 32 maintains the contact 34 out of contact with the mercury so that the other lamps remain inoperative.

In the event the filament of lamp 2 burns out the thermal member 32 will then cool to establish contact 34 into engagement with the mercury and the circuit will be completed therefrom over lead in wire 3| and wire 39 to lead in wire of lamp 2? whereupon it will operate in the same manner as lamp 2 first operated so that lamp 2 will continue to provide the lamp flashing through its filament l0 and shortly thereafter open the circuit over wire 4| to lamp 2 by breaking contact of 34 with the mercury 8 in the same manner as accomplished in lamp 2*.

Should the filament ll] of lamp 2 burn out contact 34 therein will engage the mercury in the same manner as in lamp 2 and the circuit to lamp 2 will then be established and maintained over wire 4| so that it will then flash until the supply of electricity over the wires 35 and 36 is interrupted.

The arrangement of Figure 7 illustrates the use of two additional flashing lamps for emergency use in which the first two lamps in the arrangement' are of the type disclosed in which an additional. thermally actuated contact 34 is employed and operating, if the filament in the same lamp burns out, to establish a circuit to the next lamp and wherein the last lamp in the circuit arrangement is of the form illustrated in- Figure 1. It is obvious that any number of additional lamps may be interposed in the circuit arrangement and that all may be of the same type as lamp 2 or as shown in Figure 7 the last lamp 2 may take the form of that shown in Figure 1.

What I claim is:

1. A combined incandescent lamp and flasher switch including the provision of means for retaining a pool of mercury, extending one of the leading in wires of the lamp to terminate with its end submerged in the pool of mercury, connecting the other leading in wire to one end of the lamp filament and interposing between the other end of the lamp filament and pool of mercury,

a temperature responsive mechanism normally closing the circuit within the lamp bulb and upon the establishment of an electric circuit therethrough, the passage of the current through the filament increases the temperature thereof to actuate the said mechanism to open the circuit through the lamp bulb.

2. The structure of claim 1, wherein said mechanism includes a strip of bi-metallic metal connected at one end to the lamp filament and provided at the free end with a contact member adapted to engage and be submerged within the pool of mercury.

3.. In a combined incandescent lamp and flasher switch, an incandescent lamp bulb having means formed in the bulb for retaining a pool of mercury, one of the leading in wires of the lamp having its free end submerged within the pool of mercury, an incandescent filament connected at one end to the other leading in wire, an insulated support for the other end of the filament, a strip of bi-metallic metal provided at one end with a contact member adapted to engage and disengage the pool of mercury, said strip being fixedly supported and connected in circuit with the filament support whereby heat generated by the passage of electric current through the filament will cause the bi-metallic strip to deform and withdraw its contact member from the pool of mercury to break the circuit within the bulb.

4. The structure of claim 3 wherein a third leading in wire is provided having a resilient member terminating in a contact point normally maintained in engagement with the pool of mercury and wherein said resilient member is of bimetallic metal responsive to the heat of the incandescent filament to move its contact point out of engagement with the mercury before the first bi-metallic member deforms to withdraw its contact point from the pool of mercury whereby when the filament becomes inoperative said seccnd bi-metallic member cools to move its contact into engagement with the mercury to complete a circuit in which it is interposed which circuit includes a plurality of similar combined incandescent lamp and fiasher switches.

' IRA E. MCCABE.

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