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Publication numberUS3638068 A
Publication typeGrant
Publication dateJan 25, 1972
Filing dateJan 8, 1970
Priority dateJan 8, 1970
Publication numberUS 3638068 A, US 3638068A, US-A-3638068, US3638068 A, US3638068A
InventorsWilson Hobert Earl
Original AssigneeWilson Hobert Earl, Ralph C Watson
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Dual intensity signal lamp
US 3638068 A
Abstract
A combination dual intensity signal lamp having a constant intensity control filament, a two-position switch actuated by the energization of the control filament to a second position and actuated by the deenergization of the first filament to a first position and a dual intensity signal lamp circuit containing the switch which connects the circuit for a high-intensity mode of operation in the first position and for a low-intensity mode of operation in the second position.
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Description  (OCR text may contain errors)

United States Patent Wilson 51 Jan. 25, 1972 [54] DUAL TEN ITY I NAL L M v 3,349,280 10/1967 Siiberg ..3l5/77 [72] Inventor: Robert Earl Wilson, Las Vegas, Nev. p i E i R ld L, wib n Assistant Examiner-Orville B. Chew, ll [.73] Asslgnee' fil g Watson Las Vegas a pan Attorney-Harris, Kiech, Russell& Kern [22] Filed: Jan. 8, 1970 [57] ABSTRACT [21 Appl. No.: 1,520 A combination dual intensity signal lamp having a constant intensity control filament, a two-position switch actuated by the energization of the control filament to a second position and 5 3 1 actuated by the deenergization of the first filament to a first i q 3 15/65 67 73 77 position and a dual intensity signal lamp circuit containing the l l 0 can: switch which connects the circuit for a high-intensity mode of operation in the first position and for a low-intensity mode of [56] References Cned operation in the second position.

UN'TEDSTATES PATENTS 10 Claims,'5 Drawing Figures 3,138,737 6/1964 French ..315/73 I NVENTOR.

4 HOBERT EARL W/LSON BY Hi6 HTTORNEYS B HARRIS, KIEcH, RUSSELL e2 KERN PATENTEUJANZSIQYZ 3,538,0

snm a or a HOBERT EARL W/LSON BY HIS ATTORNEYS HARE/5, /(/ECH, Aussm 1 KERN.

DUAL INTENSITY SIGNAL LAMP This invention relates to a combination dual intensity signal lamp and to a variable intensity vehicle signaling system employing the lamp.

More particularly, this invention is directed toward a combination lamp which canfunction as a rear taillamp, a rear signaling lamp, and a rear emergency brake lamp.

The present motor vehicles in use today are generally equipped with operating lamps, such as headlamps, parking lamps, taillamps, brake warning lamps and signaling lamps. In most vehicles, the taillamps serve several functions; for example, the rear taillamps are taillamps, signaling lamps, and brake warning lamps.

The combination signaling lamps presently employed on motor vehicles are single intensity lamps; that is, the lamps are energized at one brilliancy. These single intensity lamps create a serious problem in providing the proper brilliancy for both night and day time driving conditions. When the lamps are made so as to be sufficiently brilliant to be readily and easily discernible under daytime driving conditions, the lamps are too brilliant for nighttime driving conditions which causes an undesirable and hazardous glare which has a tendency to destroy night vision. When the brilliancy of the lamp is compromised so as not to make it objectionable for nighttime driving conditions, the brilliancy is inadequate for daytime driving conditions, especially on bright sunny days. The conventional method of circumventing the brilliancy problem has been to make combination tail and signaling lamps of moderate intensity. These lamps, however, are objectionable for the above reasons.

Workers in the art have also attempted to develop other solutions to the above problems. One attempted solution has been the development of dual intensity vehicle lamp systems and circuits which provide (1) that the signal and emergency lamps are of sufficient brightness during daytime driving conditions so as to be visible and (2) that the lamps are of reduced brightness during nighttime driving conditions. These systems and circuits generally employ resistor elements that are switched in and out of the signal lamp circuit to vary the intensity of the signal lamps. The switching is performed by custom circuits which embody special or custom headlamp switches or relay switches that are controlled by the custom headlamp switches, or photoelectric cells. Although these systems have satisfactorily solved the above brightness problem, these systems have not been commercially adapted because they require special circuits and special elements or parts, such as custom headlamp switches, which are expensive and which cannot be readily installed on the present vehicles. A third approach in solving the above intensity of brightness problem has been the development of dual intensity lamps for dual intensity vehicle signaling lamp circuits, such as the lamp and circuit disclosed in US. Pat. No. 3,349,280 which issued to Hemming G. Siiberg. These dual intensity lamps and circuits have satisfactorily solved the above brightness problem; however, they still present the same disadvantage seen in the above dual intensity systems and circuits; that is, the dual intensity lamps and circuits require special circuitry and custom elements which are expensive and cannot be readily installed on the present vehicles.

. For purposes of the present invention, daytime driving conditions are those conditions wherein a vehicle is operated without the operation of headlamps, and taillamps, and nighttime driving conditions are those conditions wherein a vehicle is operated with the operation of headlamps and taillamps, such as during the hours of darkness, during a dark rainy day, during a heavy fog, during a snowstorm, and the like.

It is an object of this invention to provide a combination dual intensity signal lamp which has a high-intensity mode of tensity brake warning lamp. Even more particularly, it is an object of the present invention to provide a dual function dual intensity signal lamp which operates at full brilliance during daytime driving conditions and at reduced brilliance during nighttime driving conditions when the taillamps are on.

It is another object of this invention to provide a dual intensity signal lamp that can be employed in the signaling circuits of the present vehicles to convert the vehicles rear signaling systems from a single intensity mode of operation to a dual intensity mode of operation without requiring modification of the vehicles signaling systems or circuits. Another and further object of the present invention is to provide dual intensity signal lamps which will give optimum visual signals under either daytime driving conditions or nighttime driving conditions.

The foregoing objects, advantages, features and results of the present invention, together with the various other objects, advantages, features, and results thereof which will be evident to those skilled in the signal lamp art in the light of this disclosure, may be obtained with the exemplary embodiments of the invention described in detail hereafter and illustrated in the accompanying drawings.

FIG. I is a schematic illustration of the lamp of the invention in a high-intensity mode of operation;

FIG. 2 is a schematic diagram of the lamp of FIG. I in a lowintensity mode of operation;

FIG. 3 is a schematic illustration of an alternate embodiment of the lamp in the high-intensity mode of operation;

FIG. 4 is a schematic diagram of the lamp of FIG. 3 illustrating the lamp in the low-intensity mode of operation; and

FIG. 5 is a schematic diagram of a vehicle operating lamp, signaling lamp, and a brake warning lamp circuit incorporating the dual intensity signal lamp of FIG. 1.

Referring to the drawings, FIG. 1 shows a lamp 10 having a transparent glass bulb 11 mounted on a lamp base 12 having input terminals 13 and 14 and a ground terminal 15. The input terminal 13 is connected by a wire 16 to one end of a first or control lamp filament 17, to the other end of which is connected a wire 18 which dead-ends in the base 12. The input terminal 14 is connected by a wire 19 to one end of a second or controlled lamp filament 20, to the other end of which is connected a wire 21 which dead-ends in the base 12. The wire 18 is connected by a wire 23 to a first terminal 24 of a switch 25, and the wire 19 is connected by a wire 26 through a first resistor 27 to a first contact 28 of the switch. The wire 21 is connected by a wire 29 to a second contact 30 of the switch. The wire 29 is connected by a wire 31 through a second resistance 32 to wire 33 at connection 34. Wire 33 is connected at one end to the second terminal 36 of the switch and at the other end to the ground terminal 15.

The switch 25 includes the terminals 24 and 36 and a switch arm 39 therebetween composed of a pair of metallic strips 41 and 42 bowed apart but electrically and mechanically joined at their ends. The strip 41 being of a metal having a relatively high electrical resistance and a high coefficient of expansion. The strip 42 is made of a metal having a relatively low electrical resistance and low coefiicient of expansion. The strips are supported about midway between their ends by the terminals 24 and 36 of which terminal 36 is rigidly supported in the lamp by suitable means (not shown). In the preferred embodiment of the switch, the strip 42 is prestressed to a second position (FIG. 2) and is bowed to a first position (FIG. I) by the strip 41 when no current is flowing between terminals 24 and 36. Optionally, the strip 41 can be prestressed to the first position (FIG. 1

Theswitch 25 is schematically illustrated in FIG. 1 in'its first position in which the switch connects controlled filament 20 for a high-intensity mode of operation. When the lamp 10 is energized for signaling, as when it is installed as a rear taillamp in a vehicle, current from the vehicle's signaling system flows from input terminal 14 through wire 19, controlled filament 20, wire 21, wire 29, second contact 30, the left end of strip 41, the left leg of strip 42, second terminal 36, and through wire 33 to output terminal 15. The resistance 27 is open circuited at the contact 28 of the switch and the resistance 32 is short circuited by the contact 30 and the terminal 36 of the switch. In this mode of operation the lamp is energized at relatively high brilliancy which is suitable for daytime driving conditions.

Referring to FIG. 2, the switch 25 is schematically illustrated in a second position in which the switch connects the controlled filament 20 for a low-intensity mode of operation. When the lamp is now energized for signaling, current flows from input terminal 14 through 19 controlled filament 20, wire 21, wire 29, wire 31, second resistor 32, connection 34, and through wire 33 to output terminal 15, and, starting from wire 19, through wire 26, first resistor 27, first contact 28, the left leg of strip 42, second terminal 36, and through wire 33 to the output terminal. In the low-intensity mode of operation, the controlled filament 20 is in parallel with the first resistor 27 and in series with the second resistor 32. In the low-intensity mode of operation the lamp is energized for signaling at relatively low intensity which is suitable for nighttime driving conditions.

The switch 25 remains in the first position (FIG. 1) as long as the control filament 17 is not energized. When the lamp is energized as a taillamp, the control filament 17 is energized which actuates the switch 25 from the first position to the second position (FIG. 2). More specifically, current flows from the input terminal 13 through wire 16, control filament 17, wire 18, wire 23, first contact 24, the left and right legs of metallic strip 41, the left and right legs of metallic strip 42, second contact 36 and through wire 33 to output terminal 15. The current flow through metallic strip 41 produces sufficient heat energy to cause strip 41 to expand, bow downwardly, disengage the switch arm 39 from the second contact 30, and engage the switch arm with the first contact 28. When control filament 17 is deenergized, the switch is actuated to the first position, i.e., current ceases to flow through metallic strip 41 which causes the strip to cool, contract, return to its ambient temperature configuration, disengage the switch arm from the first contact 28, and engage the switch arm with the second contact 30.

The second resistor 32 is included in the circuit to provide that the impedance between the input terminal 14 and the ground terminal is fairly constant regardless if the lamp is in the high-intensity or low-intensity mode of operation.

FIG. 3 and FIG. 4 illustrate another embodiment of the present invention with elements corresponding to those of FIG. 1 and FIG. 2 identified by the same numbers. Referring to FIG. 3, in this embodiment the lamp has a transparent glass bulb 11 mounted on a base 12 having input terminals 13 and 14 and a ground terminal 15 substantially identical to those shown in FIG. 1. The lamp has three filaments, a control filament 17 which is mounted and connected as described in FIG. 1, a high-intensity filament 44 and a low-intensity filament 45. The input terminal 14 is connected bya wire 19 to one end of the high-intensity filament 44 and one end of the low-intensity filament 45. The other end of the high-intensity filament is connected to wire 21 which dead-ends in the base 12. The other end of the low-intensity filament 45 is connected to wire 46 which dead-ends in the base 12. The wire 21 is connected by wire 29 to the second contact 30 of the switch 25. The wire 46 is connected by wire 47 to the first contact 28 of the switch 25. The switch 25 is mounted and connected as described in FIG. 1.

In the high-intensity mode of operation (FIG. 3) the control filament 17 is off, i.e., not energized, the switch 25 is in the first position, and the high-intensity filament 44 is energized, such as for signaling, as follows: current flows from the input terminal 44, through wire 19, the high-intensity filament 44, wire 21, wire 29, second contact 30, the left end of metallic strip 41, the left leg of metallic strip 42, second terminal 36 through wire 33 to the ground terminal 15.

In the low-intensity mode of operation (FIG. 4) the control filament 17 is energized, as described in FIG. 2, which actuates the switch 25 to the second position, as described in FIG. 2, and the low-intensity filament 45 is energized as follows: current flows from input terminal 14 through wire 19, the lowintensity filament, wire 46, wire 47, contact 28, the left leg of metallic strip 42, terminal 36 and through wire 33 to the ground terminal 15.

The filaments 44 and 45 are equal in impedance and equal wattage filaments, where the filament 45 is either electrically or optically inefficient. In another embodiment of the invention (not shown) the filament 44 has ahigher wattage and impedance than filament 45. In such embodiment a resistor (not shown) is electrically included in the circuit between the filament 45 and the first contact 28 to provide that the impedance between the input terminal 14 and the ground terminal is fairly constant regardless of what mode of operation the lamp Although the present invention has been described with switch 25, the invention is not limited to this switch. The present lamp can employ a two-position bimetallic switch which is actuated by the energization and deenergization of the control filament 17, a two-position relay or solenoid switch which is actuated by the energization and deenergization of the control filament, and the like.

Although not illustrated, a shunt lead can be connected from the output of the control filament 17 to the ground terminal 15 to reduce the current load across the switch 25. However, this generally will not be necessary for low-wattage lamps, such as motor vehicle taillamps.

FIG. 5 illustrates a conventional vehicle-lighting system consisting of operating lamps, emergency brake lamps and signal lamps. The operating lamps consist of the headlamps (not shown), the front parking lamps, and the rear taillamps. The left front parking lamp and left front turn signal lamp are combined into one lamp 49a; similarly, the right front parking lamp and the right front turn signal lamp are combined into a signal lamp 49b. The left taillamp, the left rear brake warning lamp and the left rear turn signal lamp are combined into one lamp 10a; similarly the right taillamp, the right rear brake warning lamp, and the rear right turn signal lamp are combined into a signal lamp 10b. Lamps 10a and 10b are of the same construction and design as lamp 10 which is illustrated in FIGS. 1 and 2.

FIG. 5 shows a battery 50 connected by a wire 51 through an ignition switch 52 to one end of a flasher element 53, the other end of which is connected to wire 54. The wire 51 is connected by a wire 55 through a hazard light flasher element 56 to one end of a hazard light switch 57, the other end of which is connected to wires 58, 59 and 60. The wire 55 is connected by wire 61 to one end of the emergency brake light switch 62, the other end of which is connected to wire 63. The wire 54 is connected through connection 66 to a left terminal 67 of a signal switch 68. The connection 66 is connected by wire 69 to a right terminal 70 of the switch 68. The wire 58 is connected to a common terminal 71. The wires 59 and 60 are connected to wires 72 and 73, respectively. The wire 63 is connected to wire 58 at connection 74. The wire 72 connects a left front contact 76 of the switch 68 with an input terminal 770 of a left front parking and signaling lamp 49 a. The wire 73 connects a right front contact 79 of the switch 68 with an input terminal 77b of a right front parking and signaling lamp 49b. The wire 72 is connected by wire 82 with one end of a left turn indicator lamp 83, the other end of which is connected to a ground contact 84. The wire 73 is connected by wire 85 with one end of a right turn indicator lamp 86, the other end of which is grounded to the terminal 84.

The switch 68 has a contact bar 88 which is engaged with the terminal 71, a left contact 89 and a right contact 90. The switch 68 also has a disengaged left contact bar 91 and a disengaged right contact bar 92. The left contact 89 is connected by wire 94 to an input terminal 140 of the left taillamp 10a. The right contact is connected by wire 95 to an input terminal 14b of the right taillamp 10b. The switch 68 is actuated by a hand lever (not shown) which upon the appropriate movement moves the contact bar 88, the left contact bar 91 and the right contact bar 92 to engage and disengage certain contacts and terminals as described below.

The battery 50 is also connected by wire 51 to an input terminal 96 of a headlamp switch 97. The input terminal 96 is connected by a slide contact 98 to a contact bar 99. The switch 97 has two taillamp contacts 101 and 102 which are connected to wire 103. The switch also has a parking lamp contact 104 which is connected to wire 105 and a headlamp contact 106 which is connected to wire 107. The wire 103 is connected to the input terminal of a license plate lamp (not shown) and input terminals 13a and 13b of the left and right taillamps a and 10b, respectively. The wire 105 is connected to input terminals 108a and l08b of the left and right front parking lamps, 49a and 4%, respectively. The wire 107 is connected to one end of a high-low beam headlamp switch (not shown), the other end of which is connected to the headlamps (not shown).

The left and right taillamps 10a and 10b have ground terminals a and 15b, respectively, which are connected by wire 109 to a rear ground contact 110.

The left and right front parking lamps 49a and 49b are of the standard type. The input terminal 77a of the left lamp 49a are connected by wire 111a to one end of a signal light filament 112a, the other end of which is connected to a ground terminal 113a. Similarly, the input terminal 77b of the right lamp 49b is connected by wire lllb to one end of a signal light filament 112b, the other end of which is connected to a ground terminal 1l3b. The input terminal 10811 of the left lamp 49b is connected by wire 114a to one end of a parking light filament 115a, the other end of which is connected to the terminal 113a. Similarly the input terminal 108b of the right lamp 49b is connected by wire 11411 to one end of a parking light filament 115b, the other end of which is connected to the terminal 1l3b The ground terminals 113a and 1l3b are connected by wire 1 16 to a front ground contact 117. The operation of the above-described vehicle lamp and signal circuit will now be described employing the dual intensity lamps of this invention.

DAYLIGI-IT OPERATION During daylight operation, the respective switches are engaged as shown in FIG. 5. When the brakes are applied, resulting in closure of brake warning switch 62, the left and right taillamps 10a and 1012, respectively, will be energized over the following circuit: from the positive terminal of the vehicle battery 50 through wire 51, wire 55, wire 61,'switch 62, wire 63, connection 74, common terminal 71, contact bar88, left contact 89, wire 94, input terminal 14a, through the left taillamp 10a over the circuit shown in FIG. 1, ground terminal 15a, and through wire 109 to the rear ground contact 110, and from .contact bar 88, through the right contact 90, wire 95, input terminal 14b, through the right taillamp 10b over the circuit shown in FIG. 1, ground terminal 15b, and through wire 109 to the rear ground contact 110. In this mode, the taillamps are ,operated as brake warning lamps at full brilliancy; i.e., the

lamps are operated in the high-intensity mode.

To signal a left turn, the directional signal switch 68 is appropriately actuated by movement of a hand lever which disengages the contact bar 88 from the right contact 90 and the common contact 71 and engages it with the left terminal 67 the left front contact 76 and the left contact 89 and engages the right contact bar 92 with the right terminal 70, the common tenninal 71, and the right contact 90. The left contact bar 91 remains disengaged. The left taillamp 10a is now energized over the following circuit: from the positive terminal of the battery 50 through wire 51, switch 52, flasher element 53, wire 54, connection 66, left terminal 67, contact bar 88, left contact 89, wire 94, input terminal 14a, through the left taillamp over the circuit shown in FIG. 1, through ground terminal 15a, and through wire 109 to the rear ground contact 110. In this mode, the left taillamp 10a is energized at full brilliancy; i.e., the controlled filament 20 of the lamp 10a is operated in the high-intensity mode. Also, when starting from the contact bar 88, the front parking lamp 49a is energized over the following circuit: through the left front contact 76, wire 72, input terminal 77a, wire 111a, filament 112a, ground terminal 113a, and through wire 116 to the front ground contact 117. Likewise, starting from left front contact 76, the left turn indicator lamp 83 is energized through wire 72, wire 82, and through the lamp83 to the ground contact 84.

To signal a right turn, the directional signal switch is appropriately actuated by movement of a hand lever which disengages the right contact bar 92 from the right terminal 70, the common terminal 71 and the right contact 90, disengages the contact bar 88 from the left terminal 67 and the contacts 76 and 89, and engages it with the right terminal 70, the right front contact 79 and the right contact 90; and engages the left contact bar 91 with the left terminal 67, the common tenninal 71 and the left contact 89. Commencing from flasher element 53, the right taillamp 106 is energized over the following circuit: from the flasher element 64 through wire 54, connection 66, wire 69, right terminal 70, the contact bar 88, right contact 90, wire 95, input terminal 1411, through the right taillamp "over the circuit shown in FIG. 1 through the ground terminal 15b, and through wire 109 to the rear ground contact 110. Also, in starting from the contact bar 88, the right parking lamp is energized over the following circuit: through the right front contact 79, wire 73, input terminal 77b, wire 111b, filament 112b, ground terminal 113a, and through wire 116 to the front ground contact 117. Likewise, and starting from the right front contact 79, the right turn indicator lamp 86 is energized over the following circuit: through wire 73, wire and through the right turn indicator lamp 86 to the ground contact 84. In this mode of operation, the right taillamp 10b is energized at full brilliancy.

When signaling a right turn, if the brakes are applied resulting in the closure of the brake switch 62, the right taillamp is energized for flashing signaling as described above and the left taillamp is energized for brake warning as described above. The right taillamp is not energized for braking because the common terminal 71 and the right contact of the switch 68 are not electrically connected when the switch is actuated for signaling a right turn. The reverse situation exists when the brakes are applied during the signaling of a left tum, i.e., the right taillamp 10b is energized for brake warning and the left taillamp 10a is energized for signaling.

When the hazard light switch 57 is closed, the directional signal switch 68 is in the position shown in FIG. 5 and the two taillamps and the two parking lamps will be concurrently energized. The left taillamp 10a is energized over the following circuit: from the positive terminal of the vehicle battery 50 through wire 51, wire 55, flashing element 56, hazard light switch 57, wire 58, common terminal 71, contact bar 88, left contact 89, wire 94, input terminal 14a, through the left taillamp 10a over the circuit shown in FIG. 1, through the ground terminal 15a, and through wire 109 to the rear ground contact 110. Similarly, from contact bar 88 the right taillamp is energized as follows: from the right contact 90, through wire 95, input terminal 14b, through the right taillamp 10b over the circuit shown in FIG. 1, through ground terminal 15b, and through wire 109 to the rear ground contact 110. Also, when starting from the hazard light switch 57, the left parking lamp 49a is energized over the following circuit: from the hazard light switch 57 through wire 59, wire 72., input terminal 77a and through the left parking lamp to the front ground contact as described above. The right parking lamp 49b is energized from the switch 57, through wire 60, wire 73, input terminal 77b and through the right parking lamp 49b to the front ground terminal 117 as described above.

OPERATION UNDER NIGI-ITTIME CONDITIONS During operation of vehicles under nighttime driving conditions, the contact bar 99 of the headlamp switch 97 is moved by the actuation of a hand lever (not shown) to engage the slide contact 98, the taillamp contact 102 and the headlamp contact 106. The taillamps are energized over the following circuit: from the positive terminal of the battery 50 through wire 51, input terminal 96, slide contact 98, contact bar 99, taillamp contact 102, wire 103, input terminals 13a and 13b of the taillamps a and 10b, respectively, through the left and right taillamps 10a and 1012 over the circuit shown in FIG. 2, through the ground terminals a and 15b, and through wire 109 to the rear ground contact 110. Starting from contact bar 99, the headlamps are energized through headlamp contact 106, wire 107 and through the high-low beam switch to the various headlamps (not shown). During nighttime driving conditions, when the brakes are applied, the rear taillamps 10a and 10b are energized as far as input terminals 14a and 14b, respectively, over the same vehicle-braking circuit described above for daytime driving conditions. From input terminal 14a of the left taillamp, the lamp is energized over the circuit shown in FIG. 2 to the ground terminal 15a and through a wire 109 to the rear ground contact 110. Similarly, from the input terminal 14b of the right taillamp 10b, the lamp is energized over the circuit shown in FIG. 2 to the ground terminal 15b. Accordingly, when the brakes are applied, the two rear taillamps 10a and 10b are not energized at full brilliancy; i.e., the rear lamps are energized in their low-intensity mode of operation which is suitable for nighttime driving conditions.

When a left turn is to be indicated by signaling through the signal lamps, up to input terminal 14a, the left taillamp is energized over vehicle signal circuit described above for a left turn under daytime driving conditions. From input terminal 14a to the ground terminal 15a of the left taillamp 10a, the lamp is energized over the circuit shown in FIG. 2. The left taillamp 10a is now energized for signaling at a reduced brilliancy in relation to the daylight operation signal brilliancy. The left front or the left parking lamp 49a is energized over the circuit described above for left turn signaling under daytime driving conditions.

When a right turn is to be indicated by signaling through a signal lamp, up to the input terminal 14b, the right taillamp 10b is energized over the vehicle signal circuit described above for a right turn under daytime driving conditions. Through the right taillamp 10b from the input terminal 14b and the ground terminal 15b, the lamp is energized over the circuit shown in FIG. 2. From the ground terminal 15b the current flows through wire 109 to the rear ground contact 110. There is no change in operation for the energization of the right parking lamp 49b for signaling, and it is energized over the circuit described above for a right turn under daytime driving conditions. When signaling a right turn, if the brakes are applied resulting in the closure of brake switch 62, the right taillamp 10a is energized for signaling as described immediately above and the left taillamp 10a is energized for brake warning over the circuit described above for braking under nighttime driving conditions.

When the hazard light switch 57 is closed, the two taillamps 10a and 10b up to input terminals 14a and 14b are concurrently energized over the same circuit described for hazard lamp operation under daytime driving conditions. However, between input terminal 14a and ground terminal 15a of the left taillamp 10a and the input terminal 14b and the ground terminal 15b of the right taillamp 10b, the lamps are energized over the circuit shown in FIG. 2. From the ground terminals 150 and 15b the current flows through wire 109 to the rear ground contact 110. Since the control filaments 17 of the rear taillamps are energized, these lamps 10a and 10b will be energized at a reduced brilliancy for hazard light operation. Since there is no change of operation for the left and front parking lamps 49a and 49b for hazard light signaling, these lamps are energized over the circuit described for hazard light operation under daytime driving conditions.

When the headlamp switch is placed on off position, i.e., the position illustrated in FIG. 5, the control filaments 17 of the left and right rear taillamps 10a and 10b are deenergized causing the lamps to revert to the high-intensity mode of operation described above. Although not shown in FIG. 5, some vehicle lighting systems provide for the energization of the parking lamps with the headlamps; such a condition would exist if wire was connected to wire 103 instead of parking lamp contact 104 of the headlamp switch 97. In such systems, the present lamps (FIGS. 1 and 2, or FIGS. 3 and 4) can be installed in the parking lamp sockets to convert the parking lamps to dual intensity lamps. For example, assuming the headlamp switch 97 was just as described immediately above, the lamp 10, as shown in FIG. 1, could be installed in place of the left parking lamp 49a where input terminal 13 would replace input terminal 108a and input terminal 14 would replace input terminal 77 and ground terminal ,15 would replace ground terminal 113a. In such a situation, when the parking lamp is not energized as a parking light, i.e., when the control filament 17 is not energized (FIG. I), the parking lamp will operate in the high-intensity mode. When the parking lamp is energized as a parking light, i.e., when the control filament 17 is energized (FIG. 2), the front parking lamp will operate in the low-intensity mode.

Although the circuit of FIG. 5 has been described employing the dual intensity signal lamp of FIGS. 1 and 2, the circuit is not limited to that embodiment of the invention. The dual intensity signal lamp of FIGS. 3 and 4 can also be employed in the above circuit to achieve the same results without requiring any modification of the circuit.

From the foregoing, it is readily apparent that the dual intensity lamp of the present invention can be employed in the taillamp-rear signal lamp circuits of the present vehicles without modification of their circuits to convert their signaling lamp systems, brake warning lamp systems and hazard lamp 7 systems from a single intensity mode of operation to a dual intensity mode of operation.

Iclaim:

l. A dual intensity lamp, including:

a base adapted to be inserted in a lamp socket;

a transparent lamp envelope mounted on said base;

first and second filaments separately mounted in said envelope, said filaments both being adapted to be electrically energized when said base is in such a socket;

a means for reducing electrical current passing through said second filament when an electrical current of predetermined load is passed through said first filament comprising a two-position switch means mounted in said lamp envelope and electrically connected to said first filament, said switch means being actuated from a first position to a second position upon the electrical energization of said first filament and actuated back to said first position upon the deenergization of said first filament; and a first resistor mounted in said envelope, said switch means in said first position electrically connecting said second filament for the passage of electrical current of a predetermined load for high-intensity operation, said switch means in said second position electrically connecting said second filament in parallel with said resistor for reducing the electrical current passing through said second filament for low-intensity operation.

2. The dual intensity lamp as defined in claim 1 wherein said base includes external first and second base terminals and a ground terminal;

said two-position switch means includes first and second metallic strips electrically connected together at their ends and bowed apart between such ends, said first strip having a relatively high electrical resistance and coefficient of expansion and said second strip having a relatively low resistance and coefficient of expansion, first and second switch terminals and first and second contacts, said first terminal being electrically connected to said first strip and said second terminal being electrically connected to said second strip;

means for electrically connecting one end of said first filament to said first base terminal and the other end of said first filament to said first switch terminal;

means for electrically connecting one end of said second filament to said second base terminal and the other end of said second filament to said first switch contact; means for electrically connecting one end of said resistor to said second base terminal and the other end of said resistor to said second switch contact; and 1 means for electrically connecting said second switch terminal to said ground terminal.

3. The dual intensity lamp as defined in claim 2 including means for electrically connecting said first switch contact through a second resistor to said base ground terminal to provide a substantially equal impedance between said second base terminal and said ground terminal.

4. The dual intensity lamp as defined in claim 1 including a second resistor mounted in said envelope, said switch means in the first position electrically shorting out said second resistor, said switch means in the second position electrically connecting said second resistor in series with said second filament.

5. A dual intensity lamp, including:

a base adapted to be inserted in a lamp socket; v

a transparent lamp envelope mounted on said base;

first, second and third filaments separately mounted in said envelope, said filaments being adapted to be electrically energized when said base is in such a socket, said second filament energized at a relatively high intensity, said third filament energized at a relatively low intensity; and

means for switching the electrical current passing through said second filament to said third filament when an electrical current of predetermined intensity is passed through said first filament, and switching back the electrical current passing through said third filament to said second filament when said first filament is electrically deenergized.

6. A dual intensity lamp as defined in claim 5 wherein the means for switching the electrical current comprises a twoposition switch means mounted in said lamp envelope and electrically connected to said first filament, said switch means being actuated from a first position to a second position upon the energization of said first filament and actuated back to said first position upon the deenergization of said first filament, said switch means in said first position electrically connecting said second filament for the passage of electrical current, and said switch means in said second position electrically connecting said third filament for the passage of electrical current.

7. The dual intensity lamp as defined in claim 6 wherein said second and third filaments are equal impedance and equal wattage filaments.

8. The dual intensitylamp as defined in claim 6 including a resistor connected in series with said third filament, the impedance of said resistor and said third filament in series being about equal to the impedance of said second filament.

9. The dual intensity lamp as defined in claim 6 wherein said base includes external first and second base terminals and a ground terminal;

said two-position switch means includes first and second switch terminals, first and second contacts, and first and second metallic strips electrically and mechanically connected together at their ends and bowed'apart between such ends, said first strip having a relatively high electrical resistance and coefficient of expansion and said second strip having a relatively low resistance and coeffi cient of expansion, said first terminal being electrically connected to said first strip and said second terminal being electrically connected to said second strip;

means for electrically connecting one end of said first filament to said first base terminal and the other end of said first filament to said first switch terminal;

means for electrically connecting one end of said second filament to said second base terminal and the other end of said second filament to said first switch contact;

means for electrically connecting one end of said third filament to said second base terminal and the other end of said third filament to said second switch contact; and means for electrically connecting said second switch terminal to said ground terminal.

20. A dual intensity lamp including:

a base having external first and second base terminals and a ground terminal; I

a transparent lamp envelope mounted on said base;

a control filament in said envelope;

a controlled filament in said envelope;

a switch in said envelope having first and second switch terminals and first and second contacts, said switch including a pair of metallic strips electrically connected together at their ends and bowed apart between such ends, one of said strips having a relatively high electrical resistance and coefficient of expansion and the other of said strips having a relatively low resistance and coefficient of expansion, one of said terminals being electrically connected to one of said strips and the other terminal being electrically connected to the other of said strips;

means electrically connecting one end of said control filament to said first base terminal and the other end of said control filament to said first switch terminal;

means for electrically connecting one end of said controlled filament to said second base terminal and through a first resistor to second switch contact and the other end of said controlled filament to said first switch contact and, through a second resistor, to said ground terminal; and

means for electrically connecting said ground terminal to said second switch terminal.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3138737 *Jan 30, 1961Jun 23, 1964Gerald H FrenchSwitching means for a load circuit with an auxiliary time delay cutout circuit
US3349280 *Jan 14, 1965Oct 24, 1967Wagner Electric CorpSignal lamp for dual intensity circuits and the like
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3958149 *Apr 30, 1975May 18, 1976The Lucas Electrical Company LimitedMotor vehicle rear lighting system
US4093894 *Nov 15, 1976Jun 6, 1978General Electric CompanyStay-on lamp
US4499398 *Jun 8, 1982Feb 12, 1985Munroe Ronald GIncandescent lighting
US5165666 *May 17, 1991Nov 24, 1992Hopkins Manufacturing CorporationLamp for vehicle lighting system
US6611105 *Mar 12, 2002Aug 26, 2003Yu-Sheng ChiuElectric bulb structure
EP0878830A1 *May 12, 1997Nov 18, 1998Luxram Licht AGIncandescent lamp for traffic signalling
Classifications
U.S. Classification315/67, 315/77, 315/73
International ClassificationH01K1/00, H01K1/64, B60Q1/26
Cooperative ClassificationB60Q1/2603, H01K1/64
European ClassificationH01K1/64, B60Q1/26A