Drive for an adjusting instrument, in particular an adjusting instrument for a motor vehicle

Abstract

Drive for an adjustment instrument, comprising a single motor configured as an electric motor energizable in two opposite directions of rotation. The output shaft of the motor is selectively couplable, via a coupling mechanism, to two separate output branches of the drive. The coupling mechanism is adjustable between a first position in which the output shaft of the electric motor is coupled to the first output branch of the drive and a second position in which the electric motor is coupled to the second output branch of the drive. For the purpose of the adjustment, the coupling mechanism comprises two cooperating coupling parts, a first coupling part with an endless guide loop, and a second coupling part. The second coupling part is equipped with a guide member that is coupled to the guide loop so as to be movable along the guide loop both in a positive and in a negative guiding direction. The guide loop comprises a sequence of successive guide loop segments which extend between a first and a second end, and which, with inclusion of a acute angle at their respective second and first ends, adjoin one another to form a drive point located at the first end. In the case of at least two successive guide loop segments, the second end of the first guide loop segment is provided with a barrier adjoining the drive point that is passable by the guide member only in a positive guiding direction extending from the first end toward the second end of that guide loop segment.

Description

[0001] Title: Drive for an adjusting instrument, in particular an adjusting instrument for a motor vehicle

[0002] The invention relates to a drive for an adjustment instrument, in particular an adjustment instrument for a motor vehicle. Adjustment instruments are generally known, and are used in particular in motor vehicles, both internally for adjusting interior parts such as headrests, and externally for adjusting body parts that influence aerodynamics, tailgates, or exterior vision units of the motor vehicle.

[0003] An adjustment instrument for an exterior vision element of a motor vehicle usually comprises a carrier that carries an exterior vision unit, such as an external mirror, camera, LIDAR and / or display. The carrier may in that case form part of the housing of the exterior vision unit, or constitute a separate component thereof. The carrier is usually adjustable via a drive, in particular an electric drive, relative to a base of the adjustment instrument that is to be mounted on the motor vehicle, with or without adjustability relative to the housing of the exterior vision unit.

[0004] The adjustment instrument is often intended to adjust the vision unit about a plurality of adjustment axes, in particular about an upright axis with respect to the fixed world and about a horizontal axis with respect to the fixed world. For example, when the exterior vision unit is in a drive position, the angle at which a driver can look via the exterior vision element can be set. The adjustment about the upright axis can then usually be carried out in two directions, i.e. from left to right and from right to left. The adjustment about the horizontal axis can likewise be carried out in two directions, i.e. from bottom to top and from top to bottom. In practice, one often speaks of a mirror glass actuator. The adjustment instrument usually comprises two plastic housing parts that are pivotally connected to one another, namely a fixing part for coupling to a support frame, and an adjusting part for coupling to the exterior vision unit. An output part is usually connected to the fixing part by two separate drives, each with its own electric motor, so that the adjustment movement of the output part that carries the exterior vision unit can be driven independently about each adjustment axis.

[0005] The adjustment instrument can also be designed to move the vision unit between a park position, in which the carrier extends substantially along the vehicle, and a folded out drive position, in which the carrier extends substantially transverse to the vehicle. Such an actuator is commonly referred to as a power-fold actuator. The base of the adjustment instrument then often comprises a foot for mounting on an exterior part of the body of the motor vehicle, and a base axis extending upward from the base relative to the fixed world for the pivotable reception of the carrier, in particular a support frame for a mirror glass actuator. The carrier is typically connected to the base by a separate drive with its own electric motor, so that the pivoting movement by which the carrier folds in and out can be carried out in a driven manner.

[0006] In a number of cases, the adjustment instrument can be provided with an actuator with two drives, each equipped with its own electric motor, by which both the pivoting movement by which the carrier is folded in and out is carried out, and the adjustment movement by which the carrier is adjusted about the upright and / or horizontal axis is caried out. The exterior vision unit can then be regarded as a two-axis power-fold actuator, or as a mirror glass actuator with a power-fold function. In such an adjustment instrument with a single actuator, the pivot axis can then coincide with the upright adjustment axis. Such an adjustment instrument is described in EP 3218226.

[0007] In practice, adjustment instruments are often provided, for each adjustment axis, with an electric motor and a drive shaft coupled thereto, which drive shaft cooperates with one adjustment axis via a transmission along a fixed drive path. The direction of rotation of the adjustment axis can then be changed only by reversing the direction of rotation of the electric motor.

[0008] A drawback of this is that, for each adjustment axis, an electrical circuit must be present by which the direction of rotation of the motor can be reversed. In the case of a direct -current electric motor, for example, a switch and wiring must be provided in the door of the car for each adjustment axis by which the motor wiring can be reversed in polarity.

[0009] Because exterior vision units often have to be adjustable about two adjustment axes, the drive of an adjustment instrument in practice contains more than one electric motor. A drawback of this is that electric motors are relatively costly and sometimes occupy scarce installation space.

[0010] To counteract this aforementioned drawback, attempts have already been made to provide a drive for an adjustment instrument by which an exterior vision unit is adjustable about two adjustment axes with only a single electric motor.

[0011] WO20 19182442 by MCi describes, in this regard, a drive for an adjustment instrument by which, with one motor operating in one direction of rotation, an adjustment axis can be adjusted in opposite directions of rotation, and by which the adjustment axis and / or the adjustment direction about the respective adjustment axes can be selected by the user, wherein the adjustment speed can be constant, and wherein the adjustment axes can be adjusted at the same motor speed. The drive for an adjustment instrument comprises a single motor, in particular an electric motor, and a drive shaft coupled thereto. The drive shaft cooperates selectively, via a transmission, with a first and a second drive path respectively. The drive comprises an operating mechanism by which the transmission is switchable between the first and the second drive path. The operating mechanism is energized by the motor and is configured, upon successive energizations of the motor starting from rest of the drive, to alternately select the first and the second drive path as the initial drive path. The operating mechanism forms a mechanical flip-flop, by which, upon successive energizations of the motor starting from rest of the drive, the first and the second drive path are alternately selected as the initial drive path.

[0012] Although the above-mentioned mechanism offers many advantages, there is still room for improvement. For example, when operated, the mechanism can sometimes carry out an undesired adjustment, for instance because the mechanism exhibits different behavior each time the same switch is operated, which can be inconvenient for users. Furthermore, it can be difficult to keep track of which drive path is selected. It can also be a drawback that two switches are needed to operate the mechanism.

[0013] The invention aims to provide a drive for an adjustment instrument by which one or more of the aforementioned drawbacks can be counteracted, or by which a user is at least offered a useful alternative. For that purpose, the invention provides a drive for an adjustment instrument according to claim 1, comprising a single motor configured as an electric motor that is drivable in two opposite directions of rotation, wherein the output shaft of the motor is selectively couplable, via a coupling mechanism, to two separate output branches of the drive, wherein the coupling mechanism is adjustable between a first position in which the output shaft of the electric motor is coupled to the first output branch of the drive and a second position in which the electric motor is coupled to the second output branch of the drive, wherein the coupling mechanism, for the purpose of the adjustment, comprises two cooperating coupling parts, a first coupling part with an endless guide loop, and a second coupling part with a guide member that is coupled to the guide loop and is movable along the guide loop in both a positive and a negative guiding direction, wherein the guide loop comprises a sequence of successive guide loop segments that extend between a first and a second end, and that, with inclusion of an acute angle and with their second and their first ends respectively, adjoin one another forming a drive point located at the first end, and wherein, of at least two successive guide loop segments, the second end of the first guide loop segment is provided with a barrier adjacent to the drive point that is passable by the guide member only in a positive guiding direction extending from the first end toward the second end of that guide loop segment.

[0014] By using an endless guide loop with guide loop segments whose ends adjoin one another at an acute angle, forming a drive point with an adjacent barrier that is passable by the guide member only in the positive guiding direction, it can be achieved that, upon energization of the motor in the same direction of rotation as a previous energization, the guide member directly drives in that direction via the drive point and drives an output stage of the drive. It is further achieved that, upon energization of the guide member in the opposite direction of rotation, the guide member does not return to the preceding guide loop segment because of the barrier, but instead moves, via the guide loop segment and while passing a next barrier, in a free movement stroke with a lateral component to a next drive point. The free movement stroke makes it possible for successive drive points to be selected without an output stage of the drive being driven. When the lateral component of the free movement stroke imposed by the acute angle corresponds to an adjustment direction of the coupling mechanism, this can be used for adjustment of the coupling mechanism. The adjusting drive can thus be configured to adjust the coupling mechanism between the first and the second position by moving the guide member, by means of a sequence of successive energization pulses of the motor in mutually opposite directions of rotation, along successive drive points. In this way it can be avoided that the mechanism performs an undesired adjustment during operation, and it becomes easier to keep track of which drive path is selected.

[0015] The guide loop segments can in each case adjoin one another, with inclusion of an acute V-angle, at their respective second and first ends while forming a drive point. As an alternative, the drive point may, for example, be located just beyond the region of junction between successive guide loop segments. The guide loop segments can then, for example, enclose an acute Y-angle. In general, the guide loop segments can adjoin one another in such a way that a drive point is formed which, in one driving direction of the motor, functions as a recess in which the guide member cannot move along the guide loop and carries the guiding structure along in the driving direction of the motor, and in which, in the opposite driving direction, the guide member can move along the guide loop and does not carry the guiding structure along.

[0016] For example, the second end of each of the guide loop segments can in each case be provided with a barrier adjacent to the drive point, which is passable by the guide member only in a positive guiding direction extending from the first end toward the second end of that guide loop segment. In such a configuration a barrier is thus provided for each guide loop segment. As an alternative, for example, only the second end of each second guide loop segment can be provided with a barrier adjacent to the drive point. In this way, for example, guide loop segments through which the guide member moves, in the free movement stroke without a lateral component, to the next drive point can be implemented without a barrier, and only guide loop segments through which the guide member moves, in the free movement stroke with a lateral component, to the next drive point can be provided with a barrier. This is because, in the case of guide loop segments without a lateral component, the guide member may, in certain configurations, encounter so little resistance while traversing the free stroke in the positive guiding direction that it is already not inclined to move back in the negative guiding direction to the preceding guide loop segment, so that the circulation direction remains positive even without a barrier.

[0017] By providing rotational play between successive drive elements of the drive branch, for example by mounting a gear wheel on the shaft with a circumferential play of 30°, a free stroke can likewise be provided, whereby successive drive points can be selected without an output stage of the drive being driven, for example as an independent or additional free stroke.

[0018] The guide loop can, for example, be embodied as a groove, and the guide member as a pin received in the groove. As an alternative, the guide loop can, for example, be embodied as a guide rail, and the guide member as a shoe enclosing the rail.

[0019] The barriers can, for example, comprise a height step in the bottom of a guide loop that is configured as a groove, with a run-up surface having a slight slope that is passable by the guide member in said positive guiding direction and a stop surface having a steep slope that is not passable by the guide member in the negative guiding direction. The guide member can then, for example, comprise a pin which, at least at the location of the height step, is spring-biased towards the bottom of the groove. As an alternative, the barriers can, for example, comprise a narrowing that is passable by the guide member in the positive guiding direction through elastic deformation of the guide member and / or the guide loop, the narrowing being not passable by the guide member in the negative guiding direction. For example, a barrier can be formed as a thickening in the guide rail that increases gradually on one side and is passable through gradual elastic deformation of the shoe, and decreases stepwise on the other side, such that it does not cause deformation of the shoe and is therefore not passable.

[0020] Advantageously, the guide loop extends along a mantle surface of a cylinder. The mantle surface can then, for example, be provided with an endless guide loop that is configured as a groove with two circular-segmentshaped guide loop segments which are spaced apart axially from each other, and which are connected via oblique guide loop segments that form oblique sides of a trapezium. As an alternative, the guide loop can, for example, extend along an end face of a disk. The guide loop can then, for example, be formed by two circular-segment-shaped guide loop segments which are spaced apart radially from each other, and which are connected by oblique guide loop segments that enclose an angle with respect to each other.

[0021] When two guide loop segments have mutually different lengths, it can be achieved that the length of the free stroke is different. The time difference associated with traversing the free strokes of different lengths can be detected to determine an absolute position of the guide member in the guide loop, which can be useful, for example, for performing a reset of the adjustment instrument. Advantageously, at least two guide loop segments can have an equal length, for example to generate adjustment strokes of equal length in order to adjust the coupling mechanism back and forth between the first and second position.

[0022] The drive can be provided with a motor controller configured to energize the motor in a sequence of successive energization pulses in mutually opposite directions of rotation, a memory for storing the current position of the guide member at a current drive point, an input for receiving a desired position of the guide member at a desired drive point, and a table with sequences of pulses to move the guide member from the current position to the desired position. In this way, it can be achieved for the adjustment instrument to be operated without a door switch, for example via a display with virtual buttons R for adjustment to the right, L for adjustment to the left, T for adjustment upwards and D for adjustment downwards. When the desired adjustment is entered, the controller can then, on the basis of the current drive position, generate a sequence of drive pulses to move the guide member without driving an output stage to the desired drive position corresponding to the desired adjustment, and subsequently, in the desired drive position, adjust the corresponding output stage in the selected direction until the virtual button is released.

[0023] When the output shaft of the motor is coupled to the coupling mechanism in a transmission ratio of 1:1, it can be achieved that the traversing of the free stroke takes place at motor speed, so that only httle time elapses until the guide member has reached the desired drive position.

[0024] When the first and / or second output branch of the drive is provided with a reduction mechanism, it can be achieved that the adjustment speed of the adjusting element that is coupled to the output branch can be relatively low.

[0025] The invention also relates to a coupling mechanism for a drive for an adjustment instrument, comprising two cooperating coupling parts, a first coupling part with an endless guide loop, and a second coupling part with a guide member that is coupled to the guide loop so as to be movable along the guide loop both in a positive and in a negative guiding direction, wherein the guide loop comprises a sequence of successive guide loop segments which extend between a first and a second end, and which, with inclusion of an acute angle at their respective second and first ends, adjoin one another to form a drive point located at the first end, and wherein, of at least two successive guide loop segments, the second end of the first guide loop segment is provided with a barrier adjoining the drive point that is passable by the guide member only in a positive guiding direction extending from the first end towards the second end of that guide loop segment.

[0026] The invention further relates to a method for adjusting a coupling mechanism of a drive, wherein the coupling mechanism is adjusted between a first and the second position by moving a guide member, by means of a sequence of successive energization pulses of a motor of the coupling mechanism in mutually opposite directions of rotation, in a positive guiding direction along successive drive points of an endless guide loop. Advantageously, successive drive points are thereby selected in a free movement stroke without an output stage of the drive being driven.

[0027] It is noted that, within this context, an electric motor is to be understood as an electrically energized motor, such as, for example, a direct- current motor (DC motor) or a stepper motor, in particular a low-voltage electric motor, i.e. an electric motor with an operating voltage of at most 48 V, preferably at most 24 V or at most 12 V.

[0028] It is further noted that the technical measures of the drive described in the paragraphs above can in each case also be applied on their own in an advantageous manner in a drive with a different configuration, i.e. the individual technical measures can, if desired, be isolated from their context and applied alone, and, if desired, combined with one or more of the measures mentioned above. The invention will be explained in greater detail with reference to exemplary embodiments shown in the drawings. The drawings show in:

[0029] Fig. la a perspective top view of an adjusting drive;

[0030] Fig. lb and Fig. 1c a perspective top view of an adjustment instrument with the adjusting drive of Fig. la;

[0031] Fig. 2 a sectional view of the adjusting drive of Fig. la;

[0032] Fig. 3 a detail of the sectional view of Fig. 2;

[0033] Fig. 4 a schematic perspective side view of the coupling mechanism of the adjusting drive of Fig. la;

[0034] Fig. 5 an exploded view of the coupling mechanism of Fig. 4;

[0035] Fig. 6 a perspective view of the first coupling part of the coupling mechanism of Fig. 4;

[0036] Fig. 7 a circuit diagram of the adjusting drive,

[0037] Fig. 8 a table with sequences of pulses to move the guide member from the circuit diagram of Fig. 7 from various current positions to various desired drive points;

[0038] Fig. 9a and Fig. 9b a schematic perspective view of a second embodiment of the coupling mechanism.

[0039] It is noted that the figures are merely schematic representations of preferred embodiments of the invention and are provided by way of nonlimiting exemplary embodiments. In the exemplary embodiments, identical or corresponding parts in the various embodiments are denoted by the same reference signs.

[0040] Figures 1-6 show a drive 1 for an adjustment instrument 2. The drive 1 is accommodated in a housing 3 of the adjustment instrument 2. In this exemplary embodiment the housing 3 is open and has a spherical upper side 4. As shown in Figures lb and 1c, the spherical upper side 4 can be provided with a hollow, also spherical-segment-shaped ring 5 of the adjustment instrument 2. The ring 5 is connected to the housing 3 by a crosspiece 6. Via the crosspiece 6 the ring 5 is pivotable relative to the housing 3 about, respectively, an X-axis oriented for example horizontally during use and a Z-axis oriented for example upright, with two separate, stacked rotational degrees of freedom. A mirror carrier plate 7 is mounted on the ring 5 to carry an adjustable mirror glass of an exterior mirror unit. The drive 1 has a first output branch 8 a and a second output branch 8b. Each output branch 8a, 8b is provided with a circular-segment-shaped rack 9a, 9b having a cylindrical drive element 10a, 10b. The racks 9a, 9b are movably mounted in parallel planes. The cylindrical drive elements 10a, 10b have center lines h forming an outward angle of 45° with the racks 9a, 9b. The cylindrical drive elements 10a, 10b are pivotably mounted in radial holes Ila, 11b of the ring 5. The holes have center lines H that enclose a mutual angle of 90°. In the initial position, the center lines h of the drive elements 10a, 10b coincide with the center lines of the holes Ila, 11b and enclose an angle of 45° with both the X-axis and the Z-axis. Each output branch 8a, 8b further comprises a reduction stage 13a, 13b driven by a worm 12a, 12b and having a sequence of transmission elements, the last transmission element 14a, 14b cooperating with the rack 9a, 9b. With positive rotation of worm 12a the drive element 10a moves upward and the mirror carrier plate 7 pivots positively about the X-axis, i.e. upward T (Top). With negative rotation of worm 12a the drive element 10a moves downward and the mirror carrier plate 7 pivots negatively about the X-axis, i.e. downward D (Down). With positive rotation of worm 12b the drive element 10b moves upward and the mirror carrier plate 7 pivots positively about the Z-axis, i.e. to the left L (Left). With negative rotation of worm 12b the drive element 10b moves downward and the mirror carrier plate 7 pivots negatively about the Z-axis, i.e. to the right R (Right). The mirror carrier plate can thus be adjusted from the initial position through an angular range of ± 15° about both the X-axis and the Z-axis.

[0041] The construction, operation and application of such an adjustment instrument are in themselves known to the skilled person from, for example, the commercially available MCi 300 mirror glass actuator, and are described in more detail in W002 / 46001 of MCi.

[0042] The drive 1 further comprises a single motor 13, which is designed as a 12 V low-voltage direct-current electric motor that is energizable in two opposite directions of rotation. The output shaft 14 of the motor is selectively couplable via a coupling mechanism 15 to the above-mentioned two separate output branches 8a, 8b of the drive 1. The coupling mechanism 15 is adjustable between a first position I in which the output shaft of the electric motor is coupled to the first output branch of the drive, and a second position II in which the electric motor 13 is coupled to the second output branch 8b of the drive 1. In the figures the mechanism is shown in the second position II. The output shaft 14 of the motor 13 is coupled with a transmission ratio of 1:1 to the first coupling part 16a of the coupling mechanism 15.

[0043] The coupling mechanism 15 comprises, for the purpose of the adjustment, two cooperating coupling parts, a first coupling part 16a, and a second coupling part 16b.

[0044] The first coupling part 16a comprises a coupling cylinder 16a' rigidly coupled to the output shaft 14 of the motor, with a mantle surface 16a" in which an endless guide loop 17 that is configured as an endless groove is provided. The second coupling part 16b comprises a coupling shaft 16b', which is mounted so as to be axially slidable and rotatable and which carries a coupling lug 16b". Worms 12a, 12b are mounted on the coupling shaft, each engaging with reduction stages 13a, 13b of the respective first and second output branches 8a, 8b of the drive 1. The worms 12a, 12b are axially fixed and freely rotatable on the coupling shaft 16', but can be carried along by the coupling lug 16b", each both in positive and in negative direction of rotation. As will be explained later, the coupling shaft 16' is axially slidable, by displacement of the guide member 18 along the endless guide loop 17, between a first coupling position I in which the coupling lug 16b" carries along the first worm 12a in rotation and is uncoupled from the second worm 12b, and the second coupling position II shown in the figures in which the coupling lug 16b" carries along the second worm 12b in rotation and is uncoupled from the first worm 12a.

[0045] The coupling shaft 16b' is further provided with a cylindrical coupling bushing 16b"' in which the coupling cylinder 16a' is slidably received. The second coupling part 16b is further provided with a guide member 18 that is configured as a guide pin. The guide member 18 that is configured as a pin, is mounted radially inwardly projecting on an auxiliary mantle 18a of resilient material, so that the guide member 18 is biased radially inward under spring action. The auxiliary mantle 18a is axially fixed between two radially outward flanges around the outside of the mantle of the coupling bushing 16b"' of the second coupling part 16b, the guide member 18 that is configured as a pin projecting radially inwardly through an opening in the mantle.

[0046] The guide member 18 that is configured as a pin is coupled to the guide loop 17 so as to be movable along the guide loop 17 in both a positive and a negative guiding direction G+ and G-, respectively. The guide loop 17 comprises a sequence of successive guide loop segments 17a, 17b, 17c, 17d. Each of the guide loop segments 17 extends between a first end 17a', 17b', 17c', 17d' and a second end 17a", 17b", 17c", 17d". The guide loop 17 in the mantle surface 16a" of the coupling cylinder 16a' of the first coupling part 16 comprises two circular-segment-shaped guide loop segments 17a, 17c. The circular-segment-shaped guide loop segments 17a, 17c are spaced apart axially from each other and are connected by oblique guide loop segments 17b, 17d forming the oblique sides of a trapezium. The two circularsegment-shaped guide loop segments 17a and 17c have different lengths, with the length of guide loop segment 17a being greater. The two oblique guide loop segments 17b and 17d have the same length and also the same length component in the axial direction.

[0047] Successive guide loop segments 17a-d adjoin each other with inclusion of an acute V-angle at, respectively, their second and their first ends, forming drive points 19a-d. The acute V-angle is less than 90°, and in this exemplary embodiment is 45°. The second end 17a"-17d" of the guide loop segments 17a-17d is in each case provided with a barrier 20 adjoining the drive point 19. The barrier 20 can be passed by the guide member 18 only in a positive guiding direction G+ extending from the first end 17a'- 17d' to the second end 17a"-17d" of that guide loop segment 17a-17d, i.e. only in a direction toward the drive point 19.

[0048] The barriers 20 are configured as a height step in the bottom of the groove of the guide loop 17. Each barrier 20 comprises a run-up surface 20a with a slight slope, passable for the guide member 18 that is configured as a pin in the positive guiding direction G+, and a stop surface 20b with a steep slope, not passable for the guide member 18 in the negative guiding direction.

[0049] The drive 1 is further provided with a motor controller (not shown) that is configured to energize the motor 13 in a sequence of successive energization pulses in mutually opposite directions of rotation, a memory (not shown) for storing the current position of the guide member at a current drive point, an input (not shown) for receiving a desired position of the guide member at a desired drive point, and a table with sequences of pulses for moving the guide member from the current position to the desired position. An example of the content of the table is shown in Fig. 8.

[0050] With reference to Fig. 7 and the table of Fig. 8, the operation of the coupling mechanism is illustrated as follows. As already explained with reference to Figs. 1-6, the drive 1 is shown with the coupling mechanism 15 in the second position II. In this position the coupling lug 16b" of the coupling shaft 16b' of the second coupling part 16b cooperates with the second worm 12b. With a negative or counterclockwise (CCW) drive of the motor 13, the coupling cylinder 16a' of the first coupling part 16a mounted on the output shaft 14 is carried along. As shown in Fig. 7, the guide pin 18 accommodated in the guide loop 17 in the mantle 16a" of the first coupling part 16a is located in the drive point 19b. As a result, the second coupling part 16b is carried along without free stroke with negative or counterclockwise (CCW) drive. The coupling shaft 16b' of the second coupling part 16b will, via the coupling lug 16b", carry along the second worm 12b counterclockwise. The second worm 12b drives the second output branch 8b, so that the drive element 10b moves upward and the mirror carrier plate 7 moves negatively about the Z-axis to the right (R).

[0051] If the motor is instead energized in the opposite direction of rotation, i.e. in the positive direction of rotation (CW), the first coupling part 16a and thereby the guide loop 17 rotate relative to the guide pin 18. Owing to the relatively steep stop surface 20b of the barrier 20 and the spring action exerted on the guide pin 18, the guide pin 18 cannot return from the drive point 19b to the preceding guide loop segment 17a. The guide pin 18 moves in the positive guiding direction via the guide loop segment 17b in which it is already located. In doing so, the guide pin 18 passes, in a free movement stroke, the passable run-up surface 20a with a relatively slight slope of the next barrier 20 and arrives at the next drive point 19c. During the run-up the guide pin 18 moves upward against the spring action. Upon reaching the steep slope of the stop surface 20b, it is then pushed back downward to the bottom of the guide loop 17 and arrives at drive point 19c. During the free movement stroke the guide pin 18 makes a movement with a lateral component corresponding to the axial direction of the coupling shaft 16b'. By the lateral component of the movement of the guide member 18 along the guide loop segment 17b, the coupling shaft 16b' is shifted axially from the second coupling position II, in which the coupling lug 16b" carries along the second worm 12b in rotation, to the first coupling position I, in which the coupling lug 16b" carries along the first worm 12a and the second worm 12b is uncoupled.

[0052] When the guide pin 18 is located in drive point 19c, the guide pin 18 will, upon continued or renewed energization of the motor in the positive direction of rotation (CW), carry along the second coupling part 16b without free stroke. The coupling shaft 16b' of the second coupling part 16b will, via the coupling lug 16b", carry along the first worm 12a in the clockwise direction. The first worm 12a drives the first output branch 8a, so that the drive element 10a moves upward and the mirror carrier plate 7 moves positively about the X-axis upward (T).

[0053] If the motor is now energized again in the opposite direction of rotation, i.e. in the negative direction of rotation I counterclockwise (CCW), the guide loop 17 in the first coupling part 16a rotates relative to the guide pin 18. From its position in drive point 19c, the guide pin 18 cannot return to the preceding guide loop segment 17b owing to the relatively steep stop surface 20b of the barrier 20 and the spring action exerted on the guide pin 18. The guide pin 18 moves in the positive guiding direction via the guide loop segment 17c in which it is already located. In doing so, the guide pin 18 passes, in a free movement stroke, the next barrier 20 via the passable runup surface 20c with a relatively slight slope and arrives at the next drive point 19d. During the run-up the guide pin 18 again moves upward against the spring action. Upon reaching the steep slope 20b of the stop surface 20 it is then pushed back downward. During the free movement stroke the guide pin 18 makes a movement without a component in the axial direction of the coupling shaft 16b'. In this displacement of the guide member 18 along the guide loop segment 17c, the coupling shaft 16b' is therefore not shifted axially and remains in the first coupling position I, in which the coupling lug 16b" carries along the first worm 12a and the second worm 12b is uncoupled.

[0054] When the guide pin 18 is located in drive point 19d, upon continued or renewed energization of the motor in the negative I counterclockwise direction of rotation (CCW), it will carry along the second coupling part 16b without free stroke. The coupling shaft 16b' of the second coupling part 16b will, via the coupling lug 16b", carry along the first worm 12a counterclockwise. The first worm 12a drives the first output branch 8a, so that the drive element 10a moves downward and the mirror carrier plate 7 moves negatively about the X-axis downward (D).

[0055] If the motor is now energized again in the opposite direction of rotation, i.e. in the positive I clockwise direction of rotation (CW), the guide loop 17 in the first coupling part 16a again rotates relative to the guide pin 18. Owing to the relatively steep stop surface 20b of the barrier 20 and the spring action exerted on the guide pin 18, the guide pin 18 cannot return from the drive point 19d to the preceding guide loop segment 17c. The guide pin 18 moves in the positive guiding direction via the guide loop segment 17d in which it is already located. In doing so, the guide pin 18 passes, in a free movement stroke, the next barrier 20 via the passable run-up surface 20a with a relatively slight slope and arrives at the next drive point 19a. During the run-up the guide pin 18 again moves upward against the spring action. Upon reaching the steep slope 20b of the stop surface 20, the guide pin 18 is then pushed back downward to the bottom of the guide loop 17.

[0056] The guide pin 18 now again makes, during the free movement stroke, a movement with a lateral component corresponding to the axial direction of the coupling shaft 16b'. By the lateral component of the movement of the guide member 18 along the guide loop segment 17b, the coupling shaft 16b' is shifted axially from the first coupling position I, in which the coupling lug 16b" carries along the first worm 12a in rotation, back to the second coupling position II, in which the coupling lug 16b" again carries along the second worm 12b and the first worm 12a is uncoupled.

[0057] When the guide pin 18 is located in drive point 19d, upon continued or renewed energization of the motor in the positive direction of rotation (CW), it will carry along the second coupling part 16b without free stroke. The coupling shaft 16b' of the second coupling part 16b will, via the coupling lug 16b", carry along the second worm 12b clockwise. The second worm 12b drives the second output branch 8b, so that the drive element 10a moves upward and the mirror carrier plate 7 moves positively about the Z-axis to the left (L).

[0058] If the motor is now energized again in the opposite direction of rotation, i.e. in the negative I counterclockwise direction of rotation (CCW), the first coupling part 16a with the guide loop 17 therein again rotates relative to the guide pin 18. From its position in drive point 19d, the guide pin 18 cannot return to the preceding guide loop segment 17d owing to the relatively steep stop surface 20b of the barrier 20 and the spring action exerted on the guide pin 18. The guide pin 18 moves in the positive guiding direction via the guide loop segment 17a in which it is already located. In doing so, the guide pin 18 passes, in a free movement stroke, the next barrier 20 via the passable run-up surface 20a with a relatively slight slope and again arrives at drive point 19b. During the run-up the guide pin 18 again moves upward against the spring action. Upon reaching the steep slope of the stop surface 20b, it is then pushed back downward to the bottom of the guide loop 17. During the free movement stroke the guide pin 18 makes a movement without a component in the axial direction of the coupling shaft 16b'. In this displacement of the guide member 18 along the guide loop segment 17c, the coupling shaft 16b' is therefore not shifted axially and remains in the second coupling position II, in which the coupling lug 16b" carries along the second worm 12b and the first worm 12a is uncoupled.

[0059] Thus, in this example, by using the single, endless guide loop 17 with guide loop segments 17a-d whose ends adjoin each other at an acute V- angle, forming a drive point 19a-d with an adjoining barrier 20 that is passable for the guide member 18 only in the positive guiding direction, it is achieved that upon energization of the motor 13 in the same direction of rotation as a preceding energization the guide member 18 directly drives via the drive point 19 in that direction and drives an output stage 8 of the drive. It is further achieved that upon energization of the motor 13 in the opposite direction of rotation, the guide member 18, owing to the barrier 20, does not return to a preceding guide loop segment, but instead moves via the guide loop segment in which it is located, under passage of a next barrier 20 in a free movement stroke, to a next drive point 19. The guide member 18 can therefore, by means of a sequence of successive energization pulses of the motor in mutually opposite directions of rotation, be moved in the positive guiding direction along successive drive points on the guide loop. The free movement stroke allows successive drive points 19 to be selected without an output branch 8 of the drive 1 being driven.

[0060] When moving in the positive guiding direction via an oblique guide loop segment from an upper circular-segment-shaped guide loop segment to a lower circular-segment-shaped guide loop segment, first a V-angle of 45 degrees to the right is made and then a V-angle of 45 degrees to the left. When subsequently moving in the positive guiding direction via the oblique guide loop segment back from the lower circular-segment-shaped guide loop segment to the upper circular-segment-shaped guide loop segment, first a V- angle of 45 degrees to the left is made and then a V-angle of 45 degrees to the right. The upper and lower circular guide loop segments are of different lengths. The time difference involved in traversing the free strokes of different lengths is detected for determining an absolute position of the guide member in the guide loop, so that, for example, a reset of the adjustment instrument can be carried out to a predetermined initial configuration.

[0061] The drive 1 of this exemplary embodiment may be provided with a motor controller configured to energize the motor in a sequence of successive energization pulses in mutually opposite directions of rotation, a memory for storing the current position of the guide member at a current drive point, an input for receiving a desired position of the guide member at a desired drive point, and a table with sequences of pulses for moving the guide member from the current position to the desired position. An example of such a table is given in Fig. 8. The adjustment instrument can, with the aid of such a motor controller, be operated without a door switch via a display with virtual buttons R for adjustment of the mirror carrier plate to the right, L for adjustment to the left, T for adjustment upward and D for adjustment downward. By selecting the virtual button, the desired adjustment is entered into the controller, and then, by means of the information from the table and on the basis of the current drive position, the controller generates a sequence of drive pulses via the motor in order to move the guide member, without driving an output branch, to the desired drive position corresponding to the desired adjustment, and subsequently, in the desired drive position, to adjust the corresponding output branch in the chosen direction until the virtual button is released.

[0062] Figures 9a and 9b show a second exemplary embodiment of the coupling mechanism. In this second embodiment, the endless guide loop 17 with guide loop segments 17a-d whose ends adjoin each other at an acute Y- angle forming a drive point 19a-d is provided with an adjoining barrier 20 at each second guide loop segment 17a, 17c next to the drive points 19a, 19c. The drive points 19a-d function as a recess in one driving direction of the motor in which the guide member 18 cannot move along the guide loop 17. In the other driving direction, the guide member 18 makes a free movement stroke with or without a lateral component depending on the guide loop segment 17a-d through which the guide member 18 moves. When the guide member 18 moves from drive point 19a, 19c to drive point 19b, 19d through guide loop segment 17a, 17c, the guide member 18 makes a free movement stroke without lateral component. The guide member 18 then encounters so little resistance to moving in the positive guiding direction that it is unnecessary to provide the drive point 19b, 19d with an adjoining barrier 20 to maintain a positive guiding direction. When the guide member 18 moves from drive point 19b, 19d to drive point 19c, 19a through guide loop segment 17b, 17d, the guide member 18 makes a free movement stroke with a lateral component. Here the drive point 19c, 19a is provided with an adjoining barrier 20 to maintain a positive guiding direction.

[0063] It is noted that the invention is not limited to the exemplary embodiments described herein. Many variants are possible. For instance, the adjusting drive can not only be applied very advantageously for generating positive and negative rotations of two adjustment axes via the output branches as in an exterior vision unit, but also for generating a translation via a first output branch, for example a combined height and inclination adjustment of a headrest. Translations can also be generated via both output branches. Furthermore, it is of course also possible for more than two output branches to be provided in the drive for the adjustment instrument, and for the coupling mechanism to be equipped with more than two coupling positions.

[0064] Such variants will be apparent to the skilled person and are considered to fall within the scope of the invention as defined in the following claims. List of reference signs

[0065] 1 Drive

[0066] 2 Adjusting element

[0067] 3 Holder

[0068] 4 Spherical upper side of holder

[0069] 5 Ring

[0070] 6 Crosspiece

[0071] 7 Mirror carrier plate

[0072] 8 a First output branch of the drive

[0073] 8b Second output branch of the drive

[0074] 9a, b Rack

[0075] 10a,b Drive element lla,b Hole

[0076] 12 a First worm

[0077] 12b Second worm

[0078] 13 Motor

[0079] 13a, b Reduction stages

[0080] 14 Output shaft of the motor

[0081] 14a, b Transmission elements

[0082] 15 Coupling mechanism

[0083] 16a First coupling part

[0084] 16a’ Coupling cylinder

[0085] 16d” Mantle

[0086] 16b Second coupling part

[0087] 16b’ Coupling shaft

[0088] 16b” Coupling lug

[0089] 16b’” Coupling bushing

[0090] 17 Guide loop

[0091] 17a-d Guide loop segment

[0092] 17a’-d’ First end of guide loop segment 17a”-d” Second end of guide loop segment

[0093] 18 Guide member

[0094] 18a Auxiliary mantle

[0095] 19a-d Drive point

[0096] 20 Barrier

[0097] 20a Run-up surface

[0098] 20b Stop surface h Centerline of drive element H Centerline of hole

[0099] T X+, Top / up

[0100] D X-, Down / down

[0101] L Z+, Left

[0102] R Z-, Right X X-axis

[0103] Z Z-axis

[0104] I First position

[0105] II Second position

Claims

Claims1. Drive for an adjustment instrument, comprising a single motor configured as an electric motor that is drivable in two opposite directions of rotation, wherein the output shaft of the motor is selectively couplable via a coupling mechanism to two separate output branches of the drive, wherein the coupling mechanism is adjustable between a first position in which the output shaft of the electric motor is coupled to the first output branch of the drive and a second position in which the electric motor is coupled to the second output branch of the drive, wherein the coupling mechanism, for the purpose of the adjustment, comprises two cooperating coupling parts, a first coupling part with an endless guide loop, and a second coupling part with a guide member that is coupled to the guide loop and is movable along the guide loop in both a positive and a negative guiding direction, wherein the guide loop comprises a sequence of successive guide loop segments that extend between a first and a second end, and that, with inclusion of a acute angle and with their second and their first ends respectively, adjoin one another forming a drive point located at the first end, and wherein, of at least two successive guide loop segments, the second end of the first guide loop segment is provided with a barrier adjacent to the drive point that is passable by the guide member only in a positive guiding direction extending from the first end toward the second end of that guide segment.

2. Drive according to any one of the preceding claims, wherein the barriers comprise a height step in the bottom of a guide loop embodied as a groove, with a run-up surface of slight incline that is passable by the guide member in said positive guiding direction and a stop surface of steep incline that is not passable by the guide member in the negative guiding direction.

3. Drive according to claim 2, wherein the guide member comprises a pin which, at least at the location of the height step, is biased toward the bottom of the groove by spring action.

4. Drive according to any one of the preceding claims, wherein the barrier comprises a narrowing that is passable by the guide member in the positive guiding direction through elastic deformation of the guide member and / or the guide loop, which is not passable by the guide member in the negative guiding direction.

5. Drive according to any one of the preceding claims, wherein the guide loop extends along a mantle surface of a cylinder.

6. Drive according to any one of the preceding claims, wherein the guide loop extends along an end face of a disk.

7. Drive according to any one of the preceding claims, wherein at least two guide loop segments have mutually different lengths.

8. Drive according to any one of the preceding claims, wherein at least two guide loop segments have equal lengths.

9. Drive according to any one of the preceding claims, wherein the drive is configured to adjust the coupling mechanism between the first and the second position by moving the guide member, by means of a sequence of successive energization pulses of the motor in mutually opposite directions of rotation, along successive drive points.

10. Drive according to any one of the preceding claims, further comprising a motor controller configured to drive the motor in a sequence of successive energization pulses in mutually opposite directions of rotation, a memory for storing the current position of the guide member at a current drive point, an input for receiving a desired position of the guide member at a desired drive point, and a table with sequences of pulses to move the guide member from the current position to the desired position.

11. Drive according to any one of the preceding claims, wherein the output shaft of the motor is coupled to the couphng mechanism in a transmission ratio of 1:1.

12. Drive according to any one of the preceding claims, wherein the first and / or second output branch of the drive is provided with a reduction mechanism.

13. Coupling mechanism for a drive for an adjustment instrument, preferably a drive according to any one of the preceding claims, comprising two cooperating coupling parts, a first coupling part with an endless guide loop, and a second coupling part with a guide member that is coupled to the guide loop and is movable along the guide loop in both a positive and a negative guiding direction, wherein the guide loop comprises a sequence of successive guide loop segments that extend between a first and a second end, and that, with inclusion of an acute angle and with their second and their first ends respectively, adjoin one another forming a drive point located at the first end, and wherein, of at least two successive guide loop segments, the second end of the first guide loop segment is provided with a barrier adjacent to the drive point that is passable by the guide member only in a positive guiding direction extending from the first end toward the second end of that guide segment.

14. Method for adjusting a coupling mechanism of a drive, preferably a coupling mechanism of a drive according to any one of the preceding claims, wherein the coupling mechanism is adjusted between a first and the second position by moving a guide member, by means of a sequence of successive energization pulses of a motor of the coupling mechanism in mutually opposite directions of rotation, in a positive guiding direction along successive drive points of an endless guide loop.

15. Method according to claim 14, wherein successive drive points are selected in a free movement stroke without an output stage of the drive being driven.

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