Automatic headlight dimmer system

• US 3,270,245 A
• Filed: 02/01/1965
• Issued: 08/30/1966
• Est. Priority Date: 06/06/1960
• Status: Expired due to Term

• Current Assignee: William C. Keeran
• Original Assignee: William C. Keeran
• Inventors: Keeran, William C.
• Application Number:
  US04/429,335
• Time in Patent Office: 575 Days
• US Class Current: 315/83
• CPC Class Codes: B60Q 1/1423 Automatic dimming circuits, i.e. switching between high beam and low beam due to change of ambient light or light level in road traffic
• CPC Class Codes: B60Q 2300/052 Switching delay, i.e. the beam is not switched or changed instantaneously upon occurrence of a condition change
• CPC Class Codes: B60Q 2300/21 Manual control
• CPC Class Codes: B60Q 2300/42 oncoming vehicle

Claims

1. IN A HEADLIGHT DIMMING SYSTEM FOR VEHICLES HAVING A HEADLIGHT WITH A HIGH BEAM FILAMENT, A LOW BEAM FILAMENT AND A SOURCE OF ELECTRIC ENERGY FOR ENERGIZING SAID FILAMENTS, THE COMBINATION OF A LIGHT SENSITIVE ELEMENT RESPONSIVE TO ILLUMINATION IMPINGING THEREON, AN ELECTRON DISCHARGE VALVE HAVING ELECTRODES INCLUDING A GRID, SAID LIGHT SENSITIVE ELEMENT BEING COUPLED TO THE GRID OF SAID VALVE FOR PLACING SAID VALVE IN A FIRST CONDITION OF OPERATION WHEN THE LEVEL OF INCIDENT LIGHT IS LOW AND FOR PLACING SAID VALVE IN A SECOND CONDITION OF OPERATION IN RESPONSE TO AN INCREASE IN THE LIGHT LEVEL, RELAY MEANS RESPONSIVE TO THE CONDITION OF THE VALVE FOR ENERGIZING THE HIGH BEAM FILAMENT IN THE FIRST CONDITION OF THE VALVE AND FOR ENERGIZING THE LOW BEAM FILAMENT IN THE SECOND CONDITION OF THE VALVE, AND TIME DELAY MEANS FOR MAINTAINING ENERGIZATION OF THE LOW BEAM FILAMENT FOR A PREDETERMINED TIME AFTER AN INCREASE IN THE LIGHT LEVEL REGARDLESS OF THE SUBSEQUENT LIGHT LEVEL, SAID TIME DELAY MEANS COMPRISING A CAPACITOR, MEANS FOR CHARGING SAID CAPACITOR WHEN THE HIGH BEAM FILAMENT IS ENERGIZED, MEANS FOR COUPLING SAID CHARGED CAPACITOR TO THE GRID UPON ENERGIZATION OF THE LOW BEAM FILAMENT FOR MAINTAINING SAID VALVE IN THE SECOND CONDITION, AND MEANS INCLUDING A BLEED RESISTOR FOR DISCHARGING SAID CAPACITOR TO ALLOW SAID VALVE TO RETURN TO THE FIRST CONDITION IN RESPONSE TO A DECREASE IN THE LIGHT LEVEL AFTER A PREDETERMINED TIME, SAID COUPLING MEANS INCLUDING A RESISTOR SUBSTANTIALLY LARGER THAN SAID BLEED RESISTOR.