GB2367120A

GB2367120A - Apparatus for controlling movement of a lamp unit relative to an automobile body

Info

Publication number: GB2367120A
Application number: GB0023468A
Authority: GB
Inventors: Ching Tang Tu
Original assignee: TYC Brother Industrial Co Ltd
Current assignee: TYC Brother Industrial Co Ltd
Priority date: 2000-09-25
Filing date: 2000-09-25
Publication date: 2002-03-27
Anticipated expiration: 2020-09-25
Also published as: GB0023468D0; GB2367120B

Abstract

An apparatus is adapted for controlling movement of a lamp unit mounted movably on an automobile body, and includes a drive shaft (45), which is mounted movably in a housing and which is adapted to be coupled to the lamp unit so as to drive movement of the same. A sensing unit (6) is mounted in the housing (7), and generates an actual position voltage that varies in accordance with angular position of the drive shaft (45) in the housing. A user-input unit (5) includes a select switch (57) connected to a voltage-divider circuit (56), which is adapted to be connected to a power source, and operable so as to select one of a plurality of desired position voltages generated by the voltage-divider circuit (56). A control unit (3) has two inputs (31, 32) coupled electrically and respectively to the user-input unit (5) and the sensing unit (6), and two outputs (33, 34) coupled electrically to a motor (4) mounted in the housing and coupled to the drive shaft (45). The control unit (3) enables operation of the motor (4) so as to drive movement of the drive shaft (45) when the actual position voltage differs from the selected one of the desired position voltages.

Description

APPARATUS FOR CONTROLLING MOVEMENT OF A LAMP UNIT RELATIVE TO AN AUTOMOBILE BODY The invention relates to an apparatus for controlling movement of a lamp unit, more particularly to an apparatus for controlling movement of a lamp unit relative to an automobile body.

Generally, an automobile has a lamp unit provided on an automobile body at a front portion. When driving, the automobile may be disposed in an inclined

orientation due to the load distribution. For example, when only the driver is seated in the automobile, the load distribution is greater at a front portion of the automobile such that the automobile inclines frontwardly. When a number of passengers are seated in the back seat of the automobile, the load distribution is greater at a rear portion of the automobile such that the automobile inclines rearwardly. Due to the variations in inclination, the projection angle of rays of light emitted by the lamp unit also varies. As such, it is necessary to adjust the lamp unit of the automobile to emit the rays of light at an appropriate projection angle according to the actual load distribution of the automobile.

Therefore, the object of the present invention is to provide an apparatus for controlling movement of a lamp unit relative to an automobile body that can be easily assembled and that can be manufactured at a

relatively low cost.

According to the present invention, an apparatus is adapted for controlling movement of a lamp unit that is mounted movably on an automobile body. The apparatus includes a housing, a drive shaft, a motor, a sensing unit, a user-input unit and a control unit.

The drive shaft is mounted movably in the housing, and has one end that extends out of the housing and that is adapted to be coupled to the lamp unit. The drive shaft is movable relative to the housing so as to drive movement of the lamp unit relative to the automobile body.

The motor is mounted in the housing and is coupled to the drive shaft. The motor is operable so as to drive movement of the drive shaft.

The sensing unit is mounted in the housing, and is associated with the drive shaft for generating an actual position voltage that varies in accordance with angular position of the drive shaft in the housing.

The user-input unit includes a voltage-divider circuit adapted to be connected to a power source and adapted to generate a plurality of desired position voltages, and a select switch connected to the voltage-divider circuit and operable so as to select one of the desired position voltages.

The control unit has first and second inputs coupled electrically and respectively to the user-input unit

and the sensing unit, and first and second outputs coupled electrically to the motor. The control unit generates a voltage difference across the first and second outputs to enable operation of the motor when the actual position voltage differs from the selected one of the desired position voltages, and ceases to generate the voltage difference to disable operation of the motor when the actual position voltage is equal to the selected one of the desired position voltages.

Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawings, of which: Figure 1 is a schematic circuit block diagram illustrating the preferred embodiment of an apparatus for controlling movement of a lamp unit according to this invention; Figure 2 is a schematic electrical circuit diagram illustrating the preferred embodiment; and Figure 3 is a partly exploded, perspective view showing the preferred embodiment.

Referring to Figures 1 to 3, according to the preferred embodiment of this invention, an apparatus is adapted for controlling movement of a lamp unit (not shown) that is mounted movably on an automobile body (not shown). The apparatus includes a housing 7, a drive shaft 45, a motor 4, a sensing unit 6, a user-input

unit 5, and a control unit 3.

The housing 7 has a seat body 72, and a cover body 71 mounted on the seat body 72.

The drive shaft 45 is mounted movably in the seat body 72 of the housing 7, and has one end 451 that extends out of the housing 7 and that is adapted to be coupled to the lamp unit. The drive shaft 45 is mounted threadedly to the housing 7, and is movable relative to the housing 7 so as to drive movement of the lamp unit relative to the automobile body. Since the particular coupling arrangement between the lamp unit and the drive shaft 45 is not critical to the present invention, a detailed description of the same will be omitted herein for the sake of brevity.

The motor 4 is mounted in the seat body 72 of the housing 7, and is coupled to the drive shaft 45 by means of a gear unit 42. The gear unit 42 includes a first gear 43, a worm 44 and a second gear 46. The first gear 43 is mounted on a main shaft 421 that is mounted in the seat body 72 of the housing 7 and that extends along a longitudinal direction parallel to a center shaft 41 of the motor 4 and transverse to the drive shaft 45, and meshes with a driving sprocket 411 provided on the center shaft 41 of the motor 4. The worm 44 is mounted on the main shaft 421 and rotates with the first gear 43. The second gear 46 is mounted on the drive shaft 45, and meshes with the worm 44. As such, the motor

4 is operable so as to drive movement of the drive shaft 45.

The sensing unit 6 is mounted in the seat body 72 of the housing 7, and is associated with the drive shaft 45 for generating an actual position voltage that varies in accordance with angular position of the drive shaft 45 in the housing 7. The sensing unit 6 includes a variable resistor 61 having a first terminal 610 adapted to be connected to a power source (Vcc), a second terminal 612 adapted to be connected the ground, and a center tap 611. In this embodiment, the variable resistor 61 is a slide potentiometer with a slider 613.

The slider 613 is disposed between a mounting plate 47 of the drive shaft 45 and the second gear 46 such that linear displacement of the drive shaft 45 that occurs when the drive shaft 45 rotates relative to the housing 7 results in corresponding adjustment of the slider 613.

The user-input unit 5 includes a voltage-divider circuit 56 adapted to be connected to the power source (Vcc) and adapted to generate a plurality of desired position voltages, and a select switch 57 connected to the voltage-divider circuit 56 and operable so as to select one of the desired position voltages. The voltage-divider circuit 56 includes a main resistor 50 and a plurality of branch resistors 51,52, 53,54, 55 of different resistances. The main resistor 50 has a

first resistor terminal 501 adapted to be connected to the power source (Vcc), and a second resistor terminal 502. The branch resistors 51,52, 53,54, 55 are connected to the second resistor terminal 502 of the main resistor 50. The voltage-divider circuit 56 is provided on a circuit board 73 mounted in the seat body 72 of the housing 7, as shown in Figure 3. The select switch 57, which is provided on a control panel of an automobile (not shown), includes a common node 570 connected to the ground, a plurality of select nodes 571,572, 573,574, 575 connected respectively to the branch resistors 51, 52, 53,54, 55 by means of connecting wires 74 connected to the circuit board 73, as shown in Figure 3, and a rotary switch 576 operable so as to connect a selected one of the select nodes 571, 572,573, 574,575 to the common node 570, thereby connecting a selected one of the branch resistors 51, 52,53, 54,55 to the ground. The selected one of the desired position voltages is obtained from the second terminal 502 of the main resistor 50.

The control unit 3, which is provided on the circuit board 73, has a first input 31 coupled electrically to the second terminal 502, a second input 32 coupled electrically to the center tap 611 of the sensing unit 6, and first and second outputs 33,34 coupled electrically to the motor 4. The control unit 3 generates a voltage difference across the first and

second outputs 33, 34 to enable operation of the motor 4 when the actual position voltage differs from the selected one of the desired position voltages, and ceases to generate the voltage difference to disable operation of the motor 4 when the actual position voltage is equal to the selected one of the desired position voltages. By means of the voltage difference, the motor 4 can drive movement of the drive shaft 45

in a clockwise or counterclockwise direction to thereby locate the lamp unit at a desired position relative to the automobile body. The control unit 3 includes first and second operational amplifier circuits 301,302.

The first operational amplifier circuit 301 has a first inverting input 3011 connected to the first input 31, a first non-inverting input 3012 connected to the second input 32, and the first output 33. The second operational amplifier circuit 302 has a second inverting input 3021 connected to the second input 32, a second non-inverting input 3022 connected to the first input 31, and the second output 34.

Because the apparatus of this invention only requires simple components, such as resistors and operational amplifier circuits, it can be easily assembled and manufactured at a relatively low cost.

The object of the invention is thus met.

Claims

CLAIMS : 1. An apparatus for controlling movement of a lamp unit that is mounted movably on an automobile body, said apparatus comprising: a housing; a drive shaft mounted movably in said housing and having one end that extends out of said housing and that is adapted to be coupled to the lamp unit, said drive shaft being movable relative to said housing so as to drive movement of the lamp unit relative to the automobile body; a motor mounted in said housing and coupled to said drive shaft, said motor being operable so as to drive movement of said drive shaft; a sensing unit mounted in said housing and associated with said drive shaft for generating an actual position voltage that varies in accordance with angular position of said drive shaft in said housing; a user-input unit including a voltage-divider circuit adapted to be connected to a power source and adapted to generate a plurality of desired position voltages, and a select switch connected to said voltage-divider circuit and operable so as to select one of the desired position voltages; and a control unit having first and second inputs coupled electrically and respectively to said userinput unit and said sensing unit, and first and second

outputs coupled electrically to said motor, said control unit generating a voltage difference across said first and second outputs to enable operation of said motor when the actual position voltage differs from the selected one of the desired position voltages, and ceasing to generate the voltage difference to disable operation of said motor when the actual position voltage is equal to the selected one of the desired position voltages.
2. The apparatus of Claim 1, wherein: said voltage-divider circuit includes: a main resistor having a first resistor terminal adapted to be connected to the power source, and a second resistor terminal; and a plurality of branch resistors of different resistances connected to said second resistor terminal of said main resistor;

said select switch includes a rotary switch operable so as to connect a selected one of said branch resistors to the ground; and the selected one of the desired position voltages is obtained from said second resistor terminal of said main resistor.
3. The apparatus of Claim 1, wherein said sensing unit includes a variable resistor having a first terminal adapted to be connected to the power source, a second terminal adapted to be connected to the ground, and a center tap connected to said control unit.
4. The apparatus of Claim 3, wherein said variable resistor is a slide potentiometer with a slider.
5. The apparatus of Claim 4, wherein said drive shaft is mounted threadedly to said housing, and said slider is coupled to said drive shaft such that linear displacement of said drive shaft that occurs when said drive shaft rotates relative to said housing results in corresponding adjustment of said slider.
6. The apparatus of Claim 1, wherein said control unit includes: a first operational amplifier circuit having a first inverting input connected to said first input, a first

non-inverting input connected to said second input, and said first output; and a second operational amplifier circuit having a second inverting input connected to said second input, a second non-inverting input connected to said first input, and said second output.
7. The apparatus for controlling movement of a lamp unit substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.