Apparatus for adjusting attitude of optical axes of head lamps on vehicle

• US 5,010,457 A
• Filed: 07/31/1990
• Issued: 04/23/1991
• Est. Priority Date: 07/31/1989
• Status: Expired due to Fees

• Current Assignee: Stanley Electric Company Limited
• Original Assignee: Stanley Electric Company Limited
• Inventors: Matsumoto, Osamu, Jyouzuka, Masashi, Suzuki, Hidenobu, Tanabe, Toru, Ohmamyuda, Yukio
• Primary Examiner(s): Husar, Stephen F.
• Application Number:
  US07/560,106
• Time in Patent Office: 266 Days
• Field of Search: 362/66, 362/71, 362/272, 362/286, 362/428, 362/276
• US Class Current: 362/466
• CPC Class Codes: B60Q 1/076 by electrical means including means to transmit the movements, e.g. shafts or joints

Abstract

An apparatus for properly adjusting an attitude of optical axes of head lamps on a vehicle includes a motor driven actuator and a controlling section. The motor driven actuator additionally includes a voltage dividing circuit comprising two resistors and one of a plurality of contact positions in the controlling section is earthed directly, whereby a resistance value of the controlling section becomes zero ohm when the angle of elevation assumed by the head lamps is maximized in an upward tilted state. A motor circuit in the motor driven actuator includes in a power supply line an element for preventing an excessive intensity of electric current from being fed to a motor when motor is held in a blocked state for some reason. Preferably, the element has positive temperature characteristics which suppress generation of heat when rotation of the motor is blocked.

Claims

1. In an apparatus for properly adjusting a head lamp on a vehicle wherein said apparatus comprises a motor driven actuator for adjusting an angle of elevation to be assumed by said head lamp and a controlling section for controlling actuation of said motor driven actuator by selectively changing a resistance value thereof, said motor driven actuator including a voltage comparing circuit, a motor circuit responsive to said comparing circuit and a potentiometer for generating a signal representative of the output position of the motor, said comparing circuit generating a signal responsive to the outputs of said potentiometer and said controlling section, said motor circuit comprising a driving circuit and a motor, and said controlling section including a switch and a plurality of resistors selectively connected to said switch via a plurality of contact positions to selectively come in contact with said switch depending on the present angle of a elevation, the improvement comprising:

a voltage dividing circuit arranged upstream of said voltage comparing circuit in the motor driven actutor, said voltage dividing circuit comprising two series connected resistors of which the common junction point between said two resistors is connected to one input terminal of said comparing circuit, one of said two resistors being connected to said switch in the controlling section; and

one of said contact positions being directly earthed, whereby said resistance value of the controlling section becomes zero ohms when the angle of elevation assumed by the head lamps is maximized in an upward tilted state being controlled by said voltage dividing circuit.

2. The apparatus as claimed in claim 1, wherein said motor circuit includes in a power supply line an element for preventing an excessive intensity of electric current from being fed to the motor therethrough when the motor is held in a blocked state, said element being arranged upstream of the motor circuit in a serial relationship relative to said power supply line.

3. The apparatus as claimed in claim 2, wherein said element has a positive temperature characteristic which desirably suppresses generation of heat when the motor is held in a blocked state.

4. Apparatus for adjusting a head lamp on a vehicle comprising:

a motor driven actuator for adjusting the angle of elevation of the head lamp and a controlling section for controlling the actuation of said motor driven actuator by selectively changing a resistance value thereof, said motor driven actuator including a voltage comparing circuit, a motor circuit operated by said voltage comparing circuit and a potentiometer for generating a voltage responsive to the position of said head lamp;

said comparing circuit comparing the voltage generated by said potentiometer with the voltage provided by said controlling circuit;

said motor circuit comprising a driving circuit and a motor;

said controlling circuit including a plurality of resistors and switch means for selectively coupling one of said resistors to said comparing circuit responsive to the desired angle of elevation of said head lamp;

a voltage dividing circuit coupled between said comparing circuit and said controlling means, said voltage dividing circuit including first and second series connected resistors, the common junction therebetween being connected to one input of said comparing circuit, one of said resistors being coupled between said common junction and said switch means;

one of said contact positions of said switch means being directly grounded, the resistance value of the resistor of the dividing circuit coupled between the common junction and said controlling circuit being selected so that the angle of elevation assumed by head lamp is maximized in an upwardly tilted orientation when said switch means is electrically connected with said directly grounded position.

5. The apparatus of claim 4 wherein a plurality of resistors selectively coupled to said switch means have different resistance values.

6. The apparatus of claim 4 wherein the remaining resistor of said first and second series connected resistors is coupled between a power supply voltage and said one input of said comparing circuit.

7. The apparatus of claim 4 further comprising:

means for swingably mounting said head lamp;

an adjusting screw means coupled between said motor means and said head lamp;

said motor means rotating said screw means by an amount and a direction responsive to the resistor coupled to said switch means.

8. The apparatus of claim 4 further comprising a power source for said motor being coupled to said motor through said driving circuit, a protection element coupled between said power source and said driving circuit for protecting the motor end driving circuit from overheating.