GB2244965A

GB2244965A - Rear-view mirror for a vehicle

Info

Publication number: GB2244965A
Application number: GB9109376A
Authority: GB
Inventors: Elio Lupo
Original assignee: Gilardini SpA
Current assignee: Marelli Europe SpA
Priority date: 1990-05-15
Filing date: 1991-05-01
Publication date: 1991-12-18
Anticipated expiration: 2011-05-01
Also published as: FR2662124B1; GB2244965B; DE4115876A1; FR2662124A1; IT220513Z2; GB9109376D0; DE4115876B4; IT9053026V0; IT9053026U1

Description

REAR-VIEW MIRROR FOR A VEHICLE The present invention relates to a lateral

rear-view mirror for a vehicle, and particularly to a mirror having mechanisms for adjusting its orientation which can be operated by electric motors. Rear-view mirrors of the said type are known in which the reflective plate is mounted on a support housed within the body of the mirror and attached to the body itself by a ball joint. The orientation of the reflective plate relative to the mirror body can be adjusted by means of two electric motors which act through suitable transmission devices to rotate the said support about two mutually- perpendicular axes which pass through the centre of the ball joint. A third electric motor adjusts the angular position of the mirror body relative to the bodywork about a substantially vertical axis about which the body is pivoted on the bodywork itself.

A disadvantage of these known mirrors of the type described is the presence of these three motors and their supply cables and control means which increase the overall cost. A further disadvantage of the use of a reflective plate which can be orientated relative to the body of the mirror is the lack of sealing between the outer edge of the reflective plate and the inner wall of the body with obvious problems due to the ingress of dust and moisture.

other rear-view mirrors are known in which the reflective is plate is fixed to the mirror body and of its orientation is adjusted by means of two electric motors housed within the body itself. Known mirrors made in accordance with the latter solution do not have the disadvantages mentioned above; they are, however, particularly complicated from a mechanical point of view and the manufacture and assembly of the components is therefore burdensome. Moreover, these mirrors do not generally allow manual adjustment of the inclination about both axes should the motors break down.

The object of the present invention is to provide an external rear-view mirror for a motor vehicle, which is free from the disadvantages connected with known mirrors as specified above.

This object is achieved by the present invention in that it relates to an external rear-view mirror for a motor vehicle, of the type including a support bracket adapted to be fixed to a side portion of the motorvehicle bodywork, a hollow outer body, a reflective plate supported in a frontal aperture in the body, first support means for the body housed at least partly within the body and mounted for rotation relative to the bracket about a first axis of rotation which is substantially-vertical, second support means for the body fixed to and housed within the body and rotatable relative to the first support means about a second, substantially-horizontal 0 axis which is parallel to the reflective plate, first drive means and first transmission means for rotating the first support means about the first axis, second drive means and second transmission means for rotating the second support means about the second axis, characterised in that the first and second drive means and the first and second transmission means are carried by the first support means.

In order to provide a better understanding of the present invention, a preferred embodiment thereof is described below, purely by way of nonlimiting example, with reference to the appended drawings, in which:

Figure 1 is a partially-sectioned plan view from above of a rear-view mirror formed in accordance with the principles of the present invention; Figure 2 is a section taken in the plane of the line II-II in Figure 1; Figure 3 is a perspective view of a control mechanism within the mirror of Figure 1, showing the components separated; and Figure 4 is a diagram of an electrical circuit associated with the mirror.

With reference to the drawings, an external rear-view mirror for a motor vehicle is generally indicated 1.

The mirror 1 includes a support 2 only part of which is illustrated and which is adapted to be fixed to a side portion of the motor-vehicle bodywork, a hollow body 3 cantilevered on one end of the bracket 2, and a reflective plate 4 fixed to the body 3 in a frontal aperture 5 thereof.

The body 3 houses a drive assembly 6 for the mirror 1 which can adjust the orientation of the body 3, and hence of the plate 4 fixed thereto, relative to the support bracket 2 by means of relative rotations about a first, substantially-vertical axis A and a second substantiallyhorizontal axis B parallel to the plane of the plate 4.

The assembly 6, illustrated in detail in Figure 3, includes a movable support 7 having a tubular end portion 8 projecting from one end of the body 3 and articulated, as will be clarified below, on a cylindrical pin 9 defining the axis A and integral with the bracket 2.

The movable support 7 is in the form of a hollow, upwardly-open box with a complex geometry; a cover 10 is fixed to the support 7 and defines a closed casing therewith. The support 7 houses a first electric motor 14 1 arranged with its axis horizontal and perpendicular to the plate 4 for rotating it about the axis A, and also houses the transmission train which couples the motor 14 rotationally to a gear 17 coaxial with the pin 9 (and hence with the axis A) and coupled to the pin as will be clarified below. The transmission train is constituted specifically by a worm gear 16 and a geared reduction unit 18 with external teeth, an input gear 19a of which is meshed with the worm 16, and an output gear 22b of which is meshed with the gear 17. More particularly, the reduction unit 18 consists of four rotors 19, 20, 21, 22 in cascade, each of which defines an integral pair of gears 19a, 19b, 20a, 20b; 21a, 21b; 22a, 22b of different diameters; the larger diameter gears 19a; 20a; 21a; 22a mesh with the preceding element in the drive train (worm 16, gears 19b, 20b, 21b respectively) while the smaller diameter gears (19b, 20b, 21b, 22b) mesh with the subsequent element in the drive train (gears 20a, 21a, 22a, 17 respectively). The rotors 19 and 21 are rotatable on a common, vertical-axis shaft 23 supported between the support 7 and the cover 10; the rotors 20 and 22 are rotatable on respective pins 24 and 25 which also have vertical axes and are supported between the support 7 and the cover 10.

The tubular end 8 of the movable support 7 houses a cylindrical bush 27 having an upper end wall 28 and a radial lower flange 29. The bush 27 is mounted on the pin 9 of the bracket 2; the end wall 28 and the flange 29 co- is operate axially with a corresponding end wall 30 of the pin 9 and an annular portion 31 of the bracket 2 surrounding the base of the pin 9, respectively. The flange 29 has a plurality of radial projections 34 of substantially semi-circular section which are adapted to fit into respective seats 35 formed in the portion 31 of the bracket 2 so as to couple the bush 27 against rotation relative to the pin 9. The gear 17 cooperates axially with the end wall 28 of the bush 27. The gear 17, the said end wall 28 and the corresponding wall 30 of the pin 9 have central apertures and house a tubular member 36 with radial end flanges 37 which constitute axial stops for respective rings 38,39 mounted on the member 36 itself. A helical spring 42 housed within the pin 9 and around the tubular member 36 is compressed between the ring 39 and the end wall 30 of the pin 9 so as, together with the gear 17 and through the member 36 and the member 38, to exert an axial compressive force on the wall 28 of the bush 27: because of the friction, frictional coupling is thus achieved between the gear 17 and the bush 27.

The said projections 34 of the bush 27 and the corresponding seats 35 in the bracket 2, under the load exerted by the spring 42, constitute a safety coupling of known type arranged to disconnect the coupling in the case of external knocks.

The tubular member 36 also constitutes a guide through 1 1 which supply cables for the electric motors 14, 55, pass into the body 3.

The bracket 2, the part of the movable support 7 projecting from the body 3 of the mirror, and those components forming the coupling between them are protected by a bellows sleeve 41, conveniently of elastermeric material.

on the opposite end of the support 7 from the bracket 2 is cantilevered a cylindrical, horizontal-axis pin 42', a tubular member 45 being mounted thereon between a pair of washers 44 and retained axially by a resilient stop-ring 46.

A cylindrical bush 50 is slidable on the tubular member 45 and constitutes the central portion of a second movable support 51 which is approximately H-shaped in that it has four substantially flat appendages 52 arranged in pairs alongside each other and formed integrally with and projecting from the bush 50. These appendages 52 bear on respective projections 53 within the body 3 and are fixed thereto by respective screws 54.

The first movable support 7 and its cover 10 also house a second electric motor 55 arranged with its axis horizontal and substantially perpendicular to the plane of the reflective plate and which rotates the second support 51 about the axis B, the support 7 also housing the 1 respective transmission train which couples the motor 15 rotationally to a gear 58 mounted on the tubular member 45 in axial abutment with an end wall 61 of the bush 50. More particularly, the transmission train consists of a worm gear 57 on the output shaft of the motor 55 and a geared reduction unit 59 with external teeth, including an input gear 64A which meshes with the worm 57 and an output gear 67B of which is meshed with the gear 58. More particularly, the reduction unit 59 is constituted by four rotors 64, 65, 66, 67 in cascade, each of which defines an integral pair of gears 64a, 64b; 65a, 65b; 66a, 66b; 67a, 67b of different diameters; the larger diameter gears 64a; 65a; 66a; 67a mesh with the preceding member in the kinematic chain (worm 57, gears 64b, 65b, 66b respectively), the smaller diameter gears 64b, 65b, 66b, 67b, mesh with the subsequent member in the kinematic chain (gears 65a, 66a, 66a, 67a, 58 respectively) the rotors 64, 66 and 65, 67 are rotatable on respective common shafts 69 and 70 arranged with their axes horizontal and parallel to the axis B and supported by the support 51.

The gear 58 is interposed axially between the bush 50 and a radial end flange 74 of the tubular member 45. A helical spring 73 housed within a cavity in the bush 50 and around the tubular member 45 is compressed between an axial shoulder 75 of the bush 50 and a stop ring 76 mounted on the tubular member 45 and retained axially by an end flange 77 of the member 45 opposite the said 1 -g- shoulder 75 so as, together with the gear 58, to exert an axial compressive force on the wall 61 of the bush 50 through the member 45: because of the friction, frictional coupling is thus achieved between the gear 58 and the bush 50 and hence the support member 51 to which the body 3 and the reflective plate 4 are fixed.

Conveniently, the electric motors 14, 55 are controlled by a conventional electronic unit 80 arranged to receive input signals from control push buttons 81, 82 within the passenger compartment of the vehicle. These push buttons may, for example, be of the rocker type such that the rotation of the motors in the two senses may be controlled through only two push buttons. Preferably the mirror 1 is also provided with position sensor means 83, shown schematically in figure 4, and arranged to supply the control unit 80 with signals indicative of the angular position of the body 3 of the mirror relative to the support bracket 2. Conveniently the control unit 80 is arranged to memorise the angular position relative to the axis A chosen by the driver. The operation of the mirror 1 is as follows.

The corresponding push button (for example 81) being operated, the unit 80 supplies the motor 14. The drive torque generated by the motor 14 is transmitted by the worm 16 to the reduction unit 18 and hence to the gear 17. This latter is held in frictional contact with the bush 27 by means of the spring 42 the load of which is such as to generate a frictional resistive torque on the gear 17 sufficient to balance the drive torque applied thereto; the bush 27 is in turn fixed against rotation relative to the bracket 2 by the engagement of the projection-.: 34 with their seats 35. Consequently, the gear 27 remains stationary and the torque generated by the motor 14 causes the output gear 22b of the reduction unit 18 to revolve around the gear 27 and, hence, the movable support 7 (whic carries the pin 25 of the gear 22b) about the bush 27 on which it is pivoted (that is, about the axis A). The body 3 of the mirror, which is fixed to the second movable support 51 carried by the first movable support 7 by means of the pin 42, is thus also rotated about the axis A.

Conveniently, the control unit 80 is programmed to vary the voltage supplied, and hence the speed of the motor 14, in dependence on the angular position of the body 3 detected by the sensor means 83; in particular, it may be convenient to identify an angle a of fine adjustment around the service position previously memorised by the unit 80 (for example, with an amplitude of 120) in which the motor is operated at low speed so as to enable a different service position to be determined. Outside this angle, it may be convenient to operate the motor 14 rapidly to enable rapid movement towards the bodywork. This rapid operation may conveniently be limited to movement in the rearward direction, which may be required 11- by the driver in certain conditions (passage through narrow gaps, etc), whilst movement in the opposite sense may be reserved to mechanical operation alone.

If the other push button 82 is operated, the control unit 10 activates the motor 55 which rotates the gear 58 through the worm gear 57 and the reduction unit 59. The gear 58 is held in axial abutment with the bush 50 by the load of the spring 73 in conditions of frictional adherence; hence, the movable support 51 and the body 3 connected thereto rotate about the axis B together with the gear 58. It is thus always possible to adjust the angular position of the mirror body 3 relative to the bracket 2 about both rotational axes A and B by manual action on the body 3 with sufficient force to overcome the frictional torque between the gear 17 and the bush 27 (for rotations about the axis A) and between the gear 58 and the bush 50 (for rotations about the axis B), these torques being produced by the loading due to the respective springs 42, 73. In such events, the gears 17 or 58 slide relative to the respective bushes 27 or 50 and enable the motor 18 or 55 and the respective drive train to be disengaged.

A study of the characteristics of the mirror 1 just described will show the advantages which it achieves.

Indeed, since the motors and their transmission members are mounted on a single support, the operating mechanism 6 is particularly simple, compact and economic to produce and assemble. In particular, the sub-assembly constituted by the support 7, the motors 14, 15 the transmission members mounted thereon and the cover 10 may be preassembled before the final assembly of the mirror, with obvious simplification of the assembly cycle.

Moreover, should the electric motors 14, 55 or the electrical circuitry fail, the operational effectiveness of the mirror is not compromised, manual adjustment always being possible. Finally, the electrical circuit required is particularly simple since the mirror includes only two motors housed within the body.

Finally, it is clear that the mirror 1 described may be modified and varied without thereby departing from the scope of protection of the present invention. For example, the arrangement of the motors 14, 55 the characteristics and arrangement of the reduction units 18, 59 and of the control logic of the unit 80 for the electric motors 14, 55 may be varied.

Claims

1. An external rear-view mirror for a motor vehicle, of the type including a support bracket adapted to be fixed to a side portion of the motor-vehicle bodywork, a hollow outer body, a reflective plate supported in a frontal aperture in the body, first support means for the body housed at least partly within the body and mounted for rotation relative to the bracket about a first axis of rotation which is substantially vertical, second support means for the body fixed to and housed within the body, and rotatable relative to the first support means about a second, substantially-horizontal axis which is parallel to the reflective plate, first drive means and first transmission means for rotating the first support means about the first axis, second drive means and second transmission means for rotating the second support means about the second axis, characterised in that the first and second drive means (15,55) and the first and second transmission means (16,18; 57,59) are carried by the first support means (7,10).

2. A mirror according to Claim 1, characterised in that it includes first frictional coupling means (17,27) for rotational coupling between the first transmission means (18) and the support bracket (2).

3. A mirror according to any one of the preceding claims, characterised in that the first transmission means include a geared reduction unit (18).

is

4. A mirror according to Claim 2, characterised in that the frictional coupling means include a gear (17) meshed with an output gear (22b) of the reduction unit, a friction surface (28) rigid with the bracket (2) and first resilient means (42) for maintaining the gear (17) in axial abutment with the friction surface (28).

5. A mirror according to Claim 4, characterised in that the bracket (2) has an integral pin (9) defining the first axis of rotation (A); the first support means (7) include a tubular portion (8) pivoted on the pin (9) with the interposition of a bush (27) fixed! to the bracket against relative rotation by engagement means (34,35) loaded by the first resilient means (42).

6. A mirror according to Claim 5, characterised in that the friction surface is constituted by an end wall (28) of the bush (27).

7. A mirror according to any one of the preceding claims, characterised in that it includes second frictional coupling means (58,50) for rotational coupling between the second transmission means (59) and the second support means (51).

1 i

8. A mirror according to any one of the preceding claims, characterised in that the second transmission means include a geared reduction unit (59).

9. A mirror according to Claim 8, characterised in that the second frictional coupling means include a gear (58) meshed with an output gear (67b) of the respective reduction unit (59), a friction surface (61) rigid with the second support means (51) and second resilient means (73) for maintaining the gear (58) in axial abutment withthe friction surface (61).

10. A mirror according to Claim 9, characterised in that the second support means (51) include an integral bush (50) rotatable on a pin (4) fixed to the first support means (7) and defining the second axis of rotation (B).

11. A mirror according to Claim 10, characterised in that the friction surface is constituted by an end wall (61) of the bush (50).

12. A mirror according to any one of Claims 8-11, characterised in that the geared reduction units (18;59) include a plurality of rotors (19,20, 21,22; 64,65,66,67), each of which defines two integral gears (19a, 19b; 20a, 20b; 21a, 21b; 22a, 22b; 64a, 64b; 65a, 65b; 66a, 66b; 67a, 67b) of different diameters, the larger of which (19a; 20a; 21a; 22a; 64a; 65a; 66a; 67a) meshes with the preceding element and the smaller of which (19b; 20b; 21b; 22b; 64b; 65b; 66b; 67b) meshes with the subsequent element of the respective transmission means.

is

13. A mirror according to any one of the preceding claims, characterised in that the first support means include an essentially box-shaped hollow support (7) and a cover (10) fixed to the support (7) and defining a closed casing therewith which houses the drive means (14,55) and the transmission means (18, 59).

14. An external rear-view mirror for a motor vehicle, substantially as described and illustrated in the appended drawings.

Published 1991 at The Patent Office, Concept House. Cardiff Road. Newport. Gwent NP9 I RH.FurLher copies may be obtained from Sales Branch. Unit 6, Nine Mile Point. Cw-mfelinfach. Cross Keys. Newport. NPI 7HZ. Printed by Multiplex techniques lid. St Mary Cray. Kent.