GB2253380A - Vehicle rear-view mirrors - Google Patents

Abstract

A vehicle has a pair of door mounted rear view mirrors (10), one mirror (10) being mounted on a door on the offside of the vehicle and the other mirror (10) being mounted on a door on the nearside of the vehicle, each mirror (10) comprising a mirror housing (12) with a mirror glass (15) pivotally mounted in the mirror housing (12), and adjustment mechanism (17) being provided for adjustment of the mirror glass (15) from a central position to positions inclined horizontally to either side of the central position, the mirrors (10) being mounted on the doors so that the mirror glasses (15) when in their central positions are inclined at equal but opposite angles to the longitudinal axis of the vehicle, both mirrors (10) having mirror glasses (15) of convex configuration. <IMAGE>

Description

VEHICLE REAR VIEW MIRRORS The present invention relates to vehicle rear view mirrors and in particular to door mounted exterior rear view mirrors.

It is common practice in modern motor vehicles, in particular cars, to provide exterior rear view mirrors on the driver's and passenger doors. Such mirrors are normally handed, as they have to be mounted on panels which will slope in opposite directions and the mirrors must be inclined oppositely to the longitudinal axis of the vehicle, so that they will provide an appropriate rearward view to the driver of the vehicle. Furthermore, as the driver is offset from the centre line of the vehicle, the angle at which the mirrors are set with respect to the longitudinal axis of the vehicle, must also differ in order to provide an appropriate field of view. For example, in a typical vehicle, the mirror on the driver's side of the vehicle may be set at 740 to the longitudinal axis of the vehicle while the mirror on the passenger side is set at 630.

In addition to mounting the mirrors at different angles to the longitudinal axis of the vehicle, adjustment means for the mirror glass must also be provided to accommodate differing positions of the driver in the vehicle, for example as the driver's seat is moved forward and backwards. Such adjustment means typically allows adjustment of the angle of the mirror glass by plus or minus 80 to 100. While it is possible this adjustment could be increased, for safety and aesthetic reasons, it is desirable that the mirror remains shrouded by its housing at its extremes of adjustment and consequently there is a limit on such adjustment, if the mirror housing is not to be made disproportionally large.

In order to provide sufficient angle of vision through the mirror on the passenger side, the mirror glass on that side must be of convex configuration. However, in order to avoid excessive distortion, such mirror glasses must have a minimum radius of curvature of 1200mm.

Although the difference in angle between the driver's side and passenger side mirrors could be accommodated by the mirror glass adjustment mechanism, there would then be insufficient adjustment to accommodate the variations in the position of the driver.

As a result of the difference between the angle of the driver and passenger side mirrors, the driver's side mirror of a right-hand drive vehicle cannot be used as a passenger side mirror of a left-hand drive vehicle and vice versa. As a result, four different wing mirror designs are required to supply a production line producing both right-hand and left-hand drive vehicles of a particular model.

It has been proposed to overcome this problem by mounting a mirror head which houses the mirror glass on a base, so that it may be located in one of two positions, one corresponding to the driver's side position of a mirror on a right-hand drive vehicle and the other to the passenger side position on a left-hand drive vehicle and vice versa. This solution will however complicate the mirror design and will also still require changeover of mirror glasses, when a plane mirror is used on the driver's side mirror.

According to one aspect of the present invention a vehicle has a pair of door mounted rear view mirrors, one mirror being mounted on a door on the offside of the vehicle and the other mirror being mounted on a door on the nearside of the vehicle, each mirror comprising a mirror housing with a mirror glass pivotally mounted in the mirror housing, an adjustment mechanism being provided for adjustment of the mirror glass from a central position to positions inclined horizontally to either side of the central position, the mirrors being mounted on the doors so that the mirror glasses when in their central positions are inclined at equal but opposite angles to the longitudinal axis of the vehicle, both mirrors having mirror glasses of convex configuration.

With the above arrangement, the mirror on the nearside door of a right-hand drive vehicle will be identical to the mirror on the offside of the left-hand drive vehicle and the mirror on the offside of a right-hand drive vehicle will be identical to the mirror on the nearside of a left-hand drive vehicle. Consequently only two designs of mirror will be required for right-hand and left-hand drive vehicles.

While setting the offside and nearside mirrors at the same angle will require a compromise in the angle at which each mirror is set, this is offset to some extent by the use of a convex mirror glass on the offside, which will significantly increase the angle of view of that mirror, thus reducing significantly the amount of adjustment required. Consequently, the compromise in the angles of the mirrors may be accommodated by means of the conventional adjustment mechanism for the mirror glasses while still retaining sufficient adjustment to accommodate variations in the driver position. If necessary, the scope of adjustment may be increased slightly say to plus or minus 100 to 150, without significantly increasing the size of the mirror head.

An embodiment of the invention is now described, by way of example only, with reference to the accompanying drawing in which: Figure 1 illustrates a wing mirror of the type used in accordance with the present invention; Figure 2 is a plan view of a vehicle in accordance with the present invention; and Figure 3 illustrates diagrammatically the field of view from the mirror glasses of a pair of conventional rear view mirrors (shown in broken line) and from the mirror glasses of a pair of rear view mirrors in accordance with the present invention (shown in full line).

As illustrated in Figures 1 and 2, the rear view mirrors 10 used in the present invention comprise a base 11 which is mounted with respect to the door 2, 3 of the vehicle 1 adjacent the leading edge thereof. A mirror head 12 is pivotally attached to the base 11 by means of a cylindrical hinge 13. The hinge 13 has a set position (as illustrated) in which it is located by suitable detent means which may be of conventional design, but is free to pivot rearwardly upon the mirror head 12 being impacted, in order to avoid damage to the mirror 10.

A convex mirror glass 15 is mounted within the mirror head 12 about a pivot 16 in known manner. An adjustment mechanism 17 is provided to adjust the inclination of the mirror glass 15 from a central position (as illustrated in full line in Figure 1) to a position inclined horizontally to either side of the central position (as illustrated in broken line in Figure 1). The adjustment mechanism may provide adjustment in the horizontal direction of 80 to 150 from the central position in each direction. The adjustment mechanism will also provide similar adjustment of the mirror glass 15 in the vertical direction.

Figure 1 illustrates the offside rear view mirror of a right hand drive vehicle or the nearside rear view mirror of a left hand drive vehicle. The nearside rear view mirror of a right hand drive vehicle or offside rear view mirror of a left hand drive vehicle will be of identical construction but of opposite hand, the angle at which the hinge 13 is set being equal but opposite to that of the mirror illustrated, so that the angle A at which the mirror 15 in its central position is set to the longitudinal axis is equal but opposite.

As illustrated in broken line in Figure 2, for a righthand drive vehicle, a plane mirror glass 20 is conventionally used on the mirror attached to the offside front door 2 of the vehicle adjacent the hinged edge thereof. A convex mirror 21 of curvature 1400mm is used on the mirror attached to the nearside front door 3 on the same transverse axis as mirror 20.

The mirror glass 20 is disposed at an angle of 740 to the longitudinal axis 5 of the vehicle while the mirror glass 21 is disposed at an angle of 630 to the longitudinal axis 5. The driver is located between the offside front door 2 and the longitudinal axis 5 and from this position, mirror 20 will give a field of view bounded by lines A B and C D and mirror 21 will give a field of view bounded by lines E F and G H.

In accordance with the present invention, both mirror glasses 25 and 26 are convex having a radius of curvature of 1400mm and are both set in their central positions at an angle of 670 to the longitudinal axis 5 of the vehicle. This will give a field of view for mirror glass 25 bounded by lines A' B' and C' D' and for mirror glass 26 bounded by lines E' F' and G' H'.

The difference in angle between mirror glasses 21 and 26 is equal to 40 and hence the field of view will be moved by 80. With mirror glasses 20 and 25, the difference in angle is 70. If mirror glass 25 were a plane mirror glass, this would shift the field of view by 140.

However, changing from a plane mirror glass 20 to a convex mirror glass 25 will reduce the effective inclination of the mirror glass 25 at edge A'. With a convex mirror glass 150mm wide and having a radius of curvature 1400mm, the inclination at edge A' will be reduced by about 30, reducing the deflection of the line A' B' by about 60. Hence the deflection from A B to A' B' upon changing from mirror glass 20 to mirror glass 25 will be about 80. The mirror glasses 25 and 26 may thus be adjusted to bring the boundaries A' B' and E' F' of the field of view back to the boundaries A B and E F respectively of the conventional mirror arrangement, by moving the mirror glasses by about 40 using the adjustment mechanism 17. This should leave sufficient adjustment to accommodate variations in the position of the driver.

Claims (5)

1. A vehicle having a pair of door mounted rear view mirrors, one mirror being mounted on a door on the offside of the vehicle and the other mirror being mounted on a door on the nearside of the vehicle, each mirror comprising a mirror housing with a mirror glass pivotally mounted in the mirror housing, an adjustment mechanism being provided for adjustment of the mirror glass from a central position to positions inclined horizontally to either side of the central position, the mirrors being mounted on the doors so that the mirror glasses when in their central positions are inclined at equal but opposite angles to the longitudinal axis of the vehicle, both mirrors having mirror glasses of convex configuration.

2. A vehicle according to Claim 1 in which each mirror comprises a base which is attached to the door adjacent its forward edge, and a mirror head pivotally attached to the base, detent means being provided to maintain the pivot in a set position, such that the mirror glass in its central position is inclined at an appropriate angle to the longitudinal axis of the vehicle, the pivot of the mirror fixed to the door on the offside of the vehicle being set at an angle equal but opposite to that of the mirror attached to the door on the nearside of the vehicle.

3. A vehicle according to Claim 1 or 2 in which each mirror has an adjustment mechanism by which the mirror may be adjusted from its central position to be inclined horizontally at an angle of from 80 to 150 to either side.

4. A vehicle according to any one of the preceding claims in which the adjusting mechanism of each mirror also adjusts the inclination of the mirror vertically.

5. A vehicle, substantially as described herein, with reference to, and as shown in, the accompanying drawings.