GB2055485A - An arrangement for the control of the beam range of motor vehicle headlights - Google Patents

Abstract

An arrangement for the control of the beam range of motor vehicle headlights comprises a driver operable switch 18 having a plurality of positions I to IV and one or more electric motor driven systems for moving the headlights into the position selected and indicated by the position of the switch. The or each motor driven system includes at least one array 36 of contacts for the corresponding electric motor 28. Each array 36 comprises contact sections 14-17 corresponding to the positions of the driver operated switch, and contact strips 11-13 alternated with the contact sections. The voltages applied to the individual contact strips of the or each array are controlled by the position of the driver operable switch to control the direction of current flow through the armature of the motor 28, which is mechanically coupled to at least one headlamp and to a respective wiper 31 for each contact array. The connections between the switch and the contact strips of the array(s) and between the contact sections and the contact strips are such that the desired position of the headlamp (and wiper 31) corresponds to a voltage- free contact section between two contact strips of different voltage to each other for each array. <IMAGE>

Description

SPECIFICATION An arrangement for the control of the beam range of motor vehicle headlights The invention originates from an arrangement according to the type set forth in the main claim.

Such an arrangement is already known in which two contact strips are connected in series and these are then connected in parallel with two other contact strips. The three positions of the contact bridge are produced by the fact that each one of the current conducting contact strips is short circuited whereupon the current path is interrupted and the contact bridge remains in the preselected position. In this position, the contact bridge short circuits two other contact strips which conduct current on further switching of the selector switch into another detent contact position and brings the contact bridge into the preselected position in the previously described manner.

If switching or reversal is carried out rapidly then, with this circuit, defective connections cannot be entirely excluded.

Advantages of the invention The arrangement in accordance with the invention comprising the features of the main claim overcomes the disadvantage of the arrangement previously referred to so that the headlight can be correctly positioned even under unfavourable operating conditions, that is to say, it takes up its adjusted positions predeterminedXby the selector switch.

Advantageous further developments and improvements of the arrangement set forth in the main claim are made possible by the measures set forth in the sub-claims. If the invention is performed according to claim 2, then only a comparatively small number of conductors and a simple circuit are required.

With the further development of the invention according to claim 3, only one of the two motor terminals needs to be reversed when the headlight needs to be pivoted into another adjusted position.

With the further development of the invention according to claim 6, both headlights are synchronously pivoted even with unfavourable voltage conditions.

Drawing Three embodiments of the invention are illustrated in the drawing and are described in more detail in the following specification. Figure 1 shows the first embodiment and Figure 2 the associated contact diagram, Figure 3 shows the second embodiment and Figure 4 the associated contact diagram; Figure 5 is the third embodiment with the associated contact diagram in Figure 6.

Description of the embodiments The arrangement for the control of the beam range of motor vehicle headlights in Figure 1 shows an adjusting element 20 associated with the left-hand headlight (not shown) and an adjusting element 20' associated with the righthand headlight 1 9'. A selector switch 1 8, shown only symbolically, is arranged within the reach of the vehicle driver and is switchable into four detent contact positions which are illustrated symbolically by I, II, III and IV. At 21 the selector switch 1 8 is connected to the positive pole and at 22 to the negative pole of the vehicle electrical system having an operating voltage of 1 2 volts.

The left-hand adjusting element 20 comprises a DC motor with a gear mechanism 29 the adjusting rod 30 of which is hinged to a first and a second contact bridge 31. A conductor 34 connects one contact bridge 31 to the first terminal 32 of the motor 28, a conductor 35 connects the other terminal 33 to the second contact bridge 31.

Each contact bridge 31 makes contact with a slide track 36 each of which is provided with four contact sections 14, 15, 1 6 and 1 7 as well as three contact strips 11, 12 and 1 3. A contact strip is arranged between two contact sections wherein the strips and the sections are mutually insulated.

Six conductors 1 to 6 lead from the selector switch 18 to the contact strips 11 to 1 3 of the slide tracks 36. Conductors 24, 25, 26 and 27 connect the conductors 1 to 6 to the contact sections 14 to 1 7 and are each provided with a diode 37 wherein the diodes 37 are connected to the two slide tracks 36 in opposite senses.

The adjusting rod 30 is pivotally mounted to a headlight which is not illustrated and referenced.

Both headlights are pivotable into the four adjustment positions I, ll, lil and IV by means of the arrangement in accordance with the invention.

The right-hand adjusting element 20' is identical to the left-hand adjusting element 20 and is connected in parallel therewith by the conductors 1' to 6'. However, like or similar parts are provided with like indexed references.

The headlight adjusted positions I to IV, which correspond to the similarly referenced positions of the contact bridges or detent contact positions of the selector switch 18, are set out in the first line of the contact diagram according to Figure 2. The conductors 1 to 6 are set out in the first column.

The operation of the arrangement illustrated in Figure 1 is as follows (only the adjusting element 20 will be described, the adjusting element 20' connected in parallel operates in a similar manner): In the illustrated position, both contact bridges 31 take up the position II, then, in accordance with the contact diagram of Figure 2, positive voltage is applied to the conductors 1, 5 and 6 so that this potential is also applied to the contact sections and contact strips to the left of the first contact bridge 31 and to the right of the second contact bridge 31. On the other hand, the remaining conducts 2, 3 and 4 receive negative voltage so that this potential prevails at the strips and bridges to the right of the first and to the left of the second bridge. Both contact sections 15, to which the contact strips 31 are connected, are free of voltage.

If the selector switch 1 8 is switched, for example, into the detent contact position Ill, then positive voltage is connected to the conductor 2 but negative voltage to the conductor 5. The contact bridges are then further connected to the contact strips 12 and by making contact with the voltage free contact sections 16, the contact bridges remain stationary; both headlights are together pivoted into the adjusted position lil.

The second embodiment in Figure 3 differs with respect to the first in that the left-hand and righthand adjusting elements 50, 50' each have only one control element, that is to say, one contact bridge, one contact section and one contact strip; however, the other parts have the same construction and the same function as in the example illustrated in Figure 1.

An apparatus 62 comprises two voltage dividers 63 and 64 each made up of two similar resistors 65 wherein one terminal is connected to negative potential 22 through a conductor 66 and the other terminal is connected to positive potential 21 through a conductor 67, of the electrical system of the vehicle. The centre tapping 68 of the voltage divider 63 is connected to one terminal 72 of the adjusting motor 48 through a conductor 69 and the centre tapping 69 of the second voltage divider 64 is connected to one terminal 72' of the adjusting motor 48' through a conductor 70. The selector switch 58 is connected to the negative at 22 and to the positive at 21 through two diodes 60 connected in opposite senses.

With the aid of the contact diagram in Figure 4, the arrangement illustrated in Figure 3 operates as follows: In position II, positive voltage is applied to the conductors 41, 41' and also to the contact strips 51, 51' and the contact sections 54, 54'; the conductors 42, 42' abd 43, 43' supply negative voltage so that this potential also arrives at the contact strips 52, 52' and 53, 53' as well as the contact sections 56, 56' and 57, 57'. The contact sections 55, 55' which are in communication with the contact bridges 61, 61' are free of voltage.

If the selector switch 58 is brought for example into the detent contact position Ill, then the conductors 42, 42' receive voltage of positive polarity. In so doing, the contact sections 56, 56' become free from voltage and the contact strips 51,51' and 52,52' and the contact sections 55, 55' and 54, 54' receive a positive potential. The contact bridges 61, 61' are then moved by the motors 48, 48' up to the voltage-free contact sections 56, 56' and remain in the position Ill; both headlights 59' have reached the adjusted position II.

The contact strips 53, 53' receive negative potential as do the contact sections 57, 57' whereby, with a possible overshoot, the motor would be automatically reversed and returned into the set position.

This also applies to the arrangement according to Figure 1 without a voltage divider.

Claims (5)

1. An arrangement for the control of the beam range of motor vehicle headlights comprising a selector switch with which are associated corresponding detent contact positions in accordance with the number of headlight positions and comprising a motor running clockwise or anticlockwise depending on the applied voltage, which is pivoted to the headlight and to a contact bridge which cooperates with contact strips which are switchable by the selector switch and brings the contact bridge into the preselected position, characterised in that, contact sections are provided corresponding to the number of headlight positions, that a contact strip is arranged between two contact sections, that the contact section associated with the preselected headlight position is voltage-free and that moreover the contact strips and contact sections lying on both sides of the voltage-free section are at a different voltage.

2. An arrangement according to claim 1 characterised in that a first and second contact bridge comprising contact strips and contact sections are associated with each headlight, that each of the two contact bridges are rigidly connected to one another and are pivoted to the associated headlight, that the first contact bridge is connected to one terminal of the motor and the second contact bridge is connected to the other terminal of the motor, that a respective conductor leads from the selector switch to the individual contact strips, that a conductor connects each contact section through diodes to the conductors for the contact strips in such a manner that operation of the similar contact sections and contact strips on both sides of the preselected contact section are at an opposite voltage.

3. An arrangement according to claim 1 characterised in that two voltage dividers are connected to the electrical system of the vehicle wherein the centre tapping of the first voltage divider is connected to one terminal of the motor for the first adjusting element and the second tapping of the second voltage divider is connected to one terminal of the adjusting motor for the second adjusting element.

4. An arrangement according to one of the preceding claims characterised in that the first headlight and the second headlight are connected in parallel.

5. An arrangement for the control of the beam range of motor vehicle headlights substantially as herein described with reference to and as illustrated in the accompanying drawings.