US2894172A

US2894172A - Reversing switching circuit for automatic headlight

Info

Publication number: US2894172A
Application number: US610545A
Authority: US
Inventors: Harold E Todd
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1956-09-18
Filing date: 1956-09-18
Publication date: 1959-07-07
Anticipated expiration: 1976-07-07

Description

H. E. TODD July 7, 1959 REVERSINC SWITCHING CIRCUIT FOR AUTOMATIC HEADLIGHT Filed Sept. 18, 1956 INVENTOK 1/ 470M 5: Z'Z ad ATTORNEY.

WARRSQM United States Patent REVERSING SWITCHING CIRCUIT FOR AUTOMATIC HEADLIGHT Harold E. Todd, Anderson, Ind., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Applicati'on September 118, 1956, Serial No. 610,545

3 Claims. (Cl. 31583) This invention relates to control switching means for electric lighting systems and more particularly to control switching means for multi-filament headlamps for automotive vehicles.

Automotive vehicles are conventionally equipped with headlamps having a bright or long range filament for country driving and a dim or short range filament for city driving. A manually operated ratchet type foot switch is conventionally provided to alternatively energize the dim or the bright filaments depending upon the driving requirements. More recently automatic light controlled means have been ofiered for switching between dim and bright filaments which means is controlled by the amount of incident light projected on the front of the vehicle from approaching cars, said light falling upon a photocell which may be mounted behind the windshield. In installations of automatic light sensitive control means, it is desirable that the driver be able to obtain at his desire manual control of the headlamp filaments or automatic control, and further that he be able to obtain opposite beam illumination at any time whether the headlamp filaments may be under manual or automatic control.

It is therefore an object in making this invention to provide control switching means for combined automatic light sensitive and manually controlled multiple filament headlamps.

It is a further object to provide control switching means for multi-filament headlamps which will always energize the alternate filament upon actuation, whether the filament energization is being controlled by automatic light sensitive means or other means.

It is still a further object to provide control switching means giving reverse beam illumination upon actuation at any time for automatically controlled multi-filament headlamps.

With these and other objects in view, which will become apparent as the specification proceeds, my invention will be best understood by reference to the following specification and claims and the illustrations in the accompanying drawing in which the drawing is a circuit diagram of a control switching system embodying my invention.

Referring now more particularly to the drawing, there is shown therein a pair of headlamps 2 and 4 each of which contains an upper beam filament 6 and 8 and a lower beam filament 10 and 12, respectively. Both of these filaments in each lamp is connected to a ground return. In order to control the energization of the desired headlamp filaments there is provided a conventional foot dimmer switch 14 which is a ratchet type of switch alternately engaging difierent contacts and remaining in its last actuated position until physically moved to the opposite contact. This provides a manual control for beam energization. The system also includes an automatic light sensitive control 16 which may be of any suitable type such, for example, as that shown in Patent 2,679,616 issued May 25, 1954, to Onksen et al. In this type of system when no light falls on the light sensitive unit a sufficiently positive bias is provided on an electronic tube so that the latter may conduct. This portion of the system is shown at tube 18, the output "voltage of the light sensitive control system 16 being applied to control grid 20 which in turn controls the flow of current between the cathode 22 and the plate 24 of the double triode tube 18. When light does fall on the light sensitive uni-t the bias on grid 20 moves in a negative direction to tend to cut off conduction through the tube and decrease the current in line 26 connected to the plate 24.

A sensitive control relay 28 having an operating coil 30 also includes a movable armature 32 which oscillates between two fixed contacts 34 and 36. The operating coil 30 has one terminal connected to line 26 and the other terminal connected to a suitable source of power indicated as 150 volts. Thus when no light falls on the light sensitive control device 16, the relay operating coil 30 is energized holding its armature 32 in the position shown in contact with lower stationary contact 36. On the other hand, when light falls on the light sensitive control device, conduction through the tube 18 is sufficiently decreased that operating coil 30 can no longer hold armature 32 in its lower position against a spring bias and armature 32 moves to engage upper contact 34.

Interconnecting the manual ratchet type foot dimmer switch 14 and the light sensitive control system with the filaments of the headlamps 2 and 4 is a compound power relay 38. This section includes a selector relay coil A and a reversing relay coil B, each of which actuates a pair of pivoted armatures tied together to move simultaneously. Relay coil A actuates a selector switch having an armature 42 and an auxiliary switch having an armature 40 and both armatures are spring biased upwardly as shown. Relay coil B, on the other hand, actuates armatures 44 and 46 which are spring biased upwardly. Armature 40 oscillates between stationary contacts 48 and 50 and armature 42 oscillates between stationary contacts 52 and 54. Stationary contact 48 is connected through conductive line 56 with cathode 58 of the second triode section of duo triode tube 18. Stationary contact 50 is connected through line 60 with stationary contact 34 of the sensitive relay 28 and one terminal of the relay coil A. Movable armature 40 is electrically connected through line 62 to stationary contact 64 on the manual ratchet dimmer switch 14. Armature 42 of the first relay is connected through line 66 with one terminal of relay coil A, one terminal of the relay coil B and the 12 volt source of power such, for example, as the storage battery of the vehicle. Stationary contact 52 of the first relay section is connected directly to armature 44 of the second relay section and stationary contact 54 is likewise connected to armature 46.

Armature 44 oscillates between two stationary contacts 68 and 70, contact 68 being connected through line 72 to one terminal of both lower beam filaments 10 and 12. Contact 70 is connected through line 74 with one terminal of both of the upper beam filaments 6 and 8 and also to stationary contact 76 associated with movable armature 46. The remaining terminal of each of the filaments is grounded. Stationary contact 78 associated with armature 46 is connected through tie line 80 with line 72 and the lower beam filaments. Line 82 connects the remaining terminal of relay coil B with stationary contact 84 on the manual ratchet switch 14. Movable armature 86 of switch 14 is grounded and is so mounted as to alternately engage stationary contacts 64 and 84. A pilot light 88 is connected between the source of power and line 82 to indicate when the device is on automatic operation.

The main advantage of this system, the operation of which will be described, is to provide alternate filament energization each time the manual ratchet dimmer switch 14 is actuated and armature 86 is moved from one stabetween aL12-volt supply and ground. Relay coil B-will also be energized through a circuit from the voltage supply line 66, coil B, line 82, contact 84, armature 86- to. ground; Thus the two armatures 44 and 46 will be held" in their lower position as'shown. If no light or only a small amount'is falling on the light sensitive control unit 16, the first triode section of the tube 18 is sufficiently conductive to permit current flow through the sensitive relay coil 3tl-so that armature 32 is drawn to the position shown. Since armature 32 does not engage contact 34, relay coil A is deenergized. Under these conditions the high beam filaments 6 and 8 should be illuminated. This energizing circuit can be traced from the 12 volt supply through line 66, armature 42, power contact 52, armature 44, contact 7 line 74 through both high beam filaments 6 and 8 to ground. If under these conditions the operator desires low beam illumination, he operates switch 14 which moves the armature 86 away from engagement with contact 84 into engagement with contact 64. This breaks the energization circuit for relay coil B and armatures 44 and 46 are drawn back to engage the upper contacts 68 and 76 instead of contacts 70 and 78 respectively. At this time the second section of tube 18 will conduct closing relay coil 31) independent of light intensity on light sensitivity control. This circuit is from ground to armature 86, to contact 64, to line 62, armature 40, to contact 48, to line '56, to cathode 58, to plate 90, to line 26, and to coil 30. Since both coils A and B are deenergized, the circuit for the low beam filament energization and illumination which was desired can be traced as follows: from the source of power line 66, armature 42, contact 52, armature 44, contact 68, line 72 through low beam filaments 12 and 18 to ground. This gives low beam illumination or reverse operation at the will of the driver. Any movement of armature 8617c tween contacts 64 and 84 merely moves armatures 44 and 46 between the stationary contacts and switches high and low beam at will as long as no light falls on the light sensitive control.

If light falls on the light sensitive control device 16 and the armature 86 is in the position shown, then the conductivity of the first triode section of the tube 18 is decreased and relay coil 30 releases its armature 32 which moves up into engagement with stationary contact 34. This completes an obvious circuit through relay coil A and under these conditions both coil A and coil B are energized. At this instant a circuit is completed to the beam filaments due to the fact that light is falling on. the photocell. This circuit may be traced as follows from the source of power, line 66, armature 42, contact 54, armature 46, contact '78, line 80, line 72 to the low beam filaments and 12, audio ground. The automatic control therefore requires lower beam. illumination at this time. If now the operator desires to overrule the automatic control and obtain high beam illumination, he again actuates manual foot dimmer switch 14 to move armature 86 to engage contact 64. This breaks the energizing circuit for relay coil B and its armatures 44 and 46 will be withdrawn by the spring bias to move to' their rear or upper contacts completing switching from low beam to high beam as desired.

One other possibility will now be described wherein it the armature 86 of the foot switch 14 is in its left hand or manual operation position in contact with 64'. Under those conditions relay coil B will remain deenergized; If it is first assumed that no light is. falling on the light sensitive control then relay coil 38 will be energized to attract its armature 32 and relay coil- A will likewise be deenergized; Under these conditions thelower" beam-filaments12 and 10 areenergized-through the foltionary contact 52, armature 44, stationary contact 68,

line 72, filaments 10 and 12 to ground. If the operator" now desires to obtain the opposite beam energization of filaments he actuates switch 14 again which completes an energizing circuit through coil B which attracts its armatures 44 and 46 which switch the beam filaments as previously described. Relay coil A at this time still remainsdeenergized due to the fact that armature 32 is maintained in its attracted position.

Finally, if armature 86 is in the left hand position in contact with stationary contact 64, relay coil A will be energized through twogrounding circuits, one through line 60, contact 50, armature 40, line 62, contact 64, armature 86 to ground and if light is falling on the light sensitive control device to deenergizecoil 30 allowing it to release its armature 32, also through this armature to ground. Then coil A will be energized and coil B will be deenergized. At this time the system is under manual control and the high beam filaments 10 and 12 will be energized through the following circuit: source of power, line 66, armature 42, contact 54, armature 46,

contact 76, line 74 and high beam filaments 6 and 8 to ground. If it is now desired under these circumstances to obtain low beam illumination, the operator moves. armature 86 back to the position shown completing an energization circuit for relay coil B and, under these conditions, coils A and B are both enengized. The energization of relay coil B will accomplish the desired switching from high to low beam by moving armatures 44 and 46 down into engagement with the lower contacts. Movement of the manual dimmer switch armature 86 away from contact 64 breaks one energizing grounding circuit for relay coil A, but with light falling on the light sensitive control device 16, the current flow through sensitive relay coil 30 is reduced to release its armature 32 so that it makes. contact with contact 34 and completes another enengizing circuit to relay coil A to maintain it energized and thus oppositebeam illumination will again be obtained by actuation of manual ratchet switch 14.

Under the immediately preceding conditions of moving manual armature 86 from engagement with contact 64 to engagement with contact 84 and if no'light has been falling on the light sensitive control, there exists a slightly different set of circumstances. Relay coil A and coil B are both deenergized and the lower beam filaments are energized. Engagement of the armature,

86 with contact 84 again energizes relay coil cap B. 1

With no light falling on light sensitive control 16, relay coil 30 is energized and it holds its armature 32 in the lower position. Thu-s there is no energizing circuit for relay coil A and its armatures. 40 and 42 are in the back position while armatures 44 and 46 are moved downwardly to switch to high beam filaments 6 and 8. Thus again a reverse filament energization is obtained.

From the above description it will be obvious that when the manual switch 14 is in the position shown, the

headlights are under automatic control and the pilot light 88 is lit to indicate this condition. When the foot dimmer switch is in its left position, the system is under manual control and the foot switch must be actuated to obtain alternate beam illumination, but under any condition actuation of the foot dimmer switch will always illuminate the alternate filaments to provide the opposite type of illumination.

I claim:

1. In a control system for vehicle headlamps, upper and lower beam filaments, a voltage source, a selector relay and a two position selector switch actuated thereby and connected with the voltage source, a reversing relay and a two position reversing switch actuated thereby and connected between the selector switch and the filaments, a dimmer switch movable between automatic and manual positions and being connected'with the reversing; 1 relay whereby each actuation of the dimmer switchto ground and movable between causes a different filament to be connected to the voltage source through the reversing switch, a light sensitive control circuit including a control relay and a control switch actuated thereby and connected with the selector relay to cause actuation of the selector switch in accordance with incident light intensity and selectively connect one of the filaments with the voltage source through the reversing switch when the dimmer switch is in the automatie" position, and auxiliary switch actuated by the selector relay and being connected with the dimmer switch, a holding circuit for the selector relay including saiddimmer switch in the manual position and the auxiliary switch when the selector switch is in one position, and a holding circuit for the control relay including the dimmer switch in the manual position and the auxiliary switch when the selector switch is in the other position.

2. In a controlsystem for vehicle headlamps, upper and lower beam filaments, a voltage source having one terminal connected to ground, a selector relay and a two position selector switch actuated thereby and connected with the other terminal of the voltage source, a reversing relay and a two position reversing switch actuated thereby and connected between the selector switch and the filaments, said relays each having one terminal connected with the other terminal of the voltage source, a dimmer switch having an armature contact connected automatic and manual positions and engaging first and second contacts respectively, said first contact being connected with the other terminal of the reversing relay whereby each actuation of the dimmer switch causes a different filament to be connected with the reversing switch, a light sensitive control circuit including a control relay, means applying a voltage to one terminal of the control relay, a control switch actuated by the control relay and connecting the other terminal of the selector relay to ground to cause actuation of the selector switch in accordance with incident light intensity and selectively connect one of the filaments with the voltage source through the reversing switch, and means to prevent actuation of the selector switch when the dimmer switch is in the manua position, said means comprising an auxiliary switch actuated by the selector relay and having a movable contact and first and second fixed contacts, the movable contact of the auxiliary switch being connected with the second fixed contact of the dimmer switch, the first fixed contact of the auxiliary switch being connected with said other terminal of the selector relay to complete a holding circuit therefor when the selector switch is in one position, the second fixed contact of the auxiliary switch being connected with the other terminal of the control relay h to complete a holding circuit therefor when the selector switch is in the other position.

3. In a control system for vehicle headlamps, upper and lower beam filaments, a voltage source having one terminal connected to ground, a selector relay and a selector switch actuated thereby and having a movable contact connected with the voltage source and a pair of fixed contacts, a reversing relay and a reversing switch actuated thereby and having a pair of movable contacts connected with respective fixed contacts of the selector switch, the reversing switch also having associated with each of its movable contacts a pair of fixed contacts, one of each pair being connected to one filament and the other of each pair being connected with the other filament, said relays each having one terminal connected with the other terminal of the voltage source, a dimmer switch having an armature contact connected to ground and movable between automatic and manual positions and engaging first and second contacts respectively, said first contact being connected with the other terminal of the reversing relay whereby each actuation of the dimmer switch causes a different filament to be com nected to the voltage source through the reversing switch, a light sensitive control circuit including a control relay,- means applying a voltage to one terminal of the control relay, a control switch actuated by the control relay and connecting the other terminal of the selector relay to ground to cause actuation of the selector switch in accordance with incident light intensity to selectively connect one of the filaments with the voltage source through the reversing switch, and means to prevent actuation of the selector switch when the dimmer switch is in the manual position, said means comprising an auxiliary switch actuated by the selector relay and having a movable contact and first and second fixed contacts, the movable contact of the auxiliary switch being connected with the second fixed contact of the dimmer switch, the first fixed contact of the auxiliary switch being connected with the said other terminal of the selector relay to complete a holding circuit therefor when the selector switch is in one position, the second fixed contact of the auxiliary switch being connected with the other terminal of the control relay to complete a holding circuit therefor when the selector switch is in the other position.

References Cited in the file of this patent UNITED STATES PATENTS 2,431,394 Friedman Nov. 25, 1947 2,679,616 Onksen et al May 25, 1954 2,761,995 Du Rocker Sept. 4, 1956 2,825,851 Lidiak Mar. 4, 1958