GB2177985A - Car rear view extension mirror - Google Patents

Abstract

An extension mirror assembly for fitting over an existing door-mounted mirror (40) (for use when towing a caravan) comprises a mirror unit 10 (Figure 1) and two straps 35 (Figure 4). The mirror unit 10 has a mirror 50 on a ball joint mounting housed in its outer end 13. Its inner end 11 has four cranked brackets (12A-D), mounted in respective slots, which can be moved vertically and then fixed in position by tightening respective locking bolts. The mirror unit is placed over the glass side of the door mirror (40), the brackets are adjusted so that their cranked ends fit snugly against the door mirror, and the D pieces (37) of the straps are then fitted over the ends of the brackets and the straps tightened on the other side of the door mirror (40) to hold the mirror unit firmly in place. An optional strut 16 braces the unit against the car door. <IMAGE>

Description

SPECIFICATION Car rear view mirrors The present invention relates to car rear view mirrors, and more specifically to extension mirrors intended for mounting over existing door-mounted mirrors.

For a very long time, almost all cars have had one or more external mirrors. For many years these mirrors were mounted on the wings of the car, the mirror being attached by means of an adjustable ball-style joint to a strut which was in turn mounted rigidly on the car wing. More recently, it has become the practice to mount such mirrors on the car door rather than the wing. More recently still, it has become usual to provide a somewhat more complicated mounting so that the mirror can be adjusted by the driver from inside the car, and in recent designs, such adjustment moves only the glass of the mirror in a fixed housing which is rigidly attached to the door.

There is a need, with almost all cars, for extension mirrors which project further from the car than the normal rear-view mirrors, so that a rear view can be obtained when towing a caravan which is wider than the car. A well-known form of extension mirror is constructed so that it can be mounted over an existing rear-view mirror. These known designs are intended to be fixed rigidly to the existing mirror. Thus the necessary adjustment which any rear view mirror must be capable of is achieved, with known designs, by taking advantage of the adjustability of the existing mirror; the extension mirror is moved for adjustment with the existing mirror on which it is mounted.

This arrangement, however, is unsatisfactory for use with the more modern type of rear-view mirror which is door mounted and which often consists of a fixed housing in which only the glass is adjustable. Existing extension mirror designs are often not capable of being mounted on such a mirror, which presents a less convenient shape on which to attach an extension mirror. Also, the adjustability of existing designs is often non-existent in such use.

Although it has been proposed to provide adjustment means which couple the extension mirror to the glass in the existing mirror, this reduces the rigidity of the mounting of the extension mirror, which tends to be low in any case in such use.

A further disadvantage of existing extension mirrors is that they are liable to cause the mirror mounting to deflect at high speeds, because of the increased wind resistance of the extension mirror.

Of course, the mounting of the existing mirror is made to yield at high pressure, for safety reasons.

The object of the present invention is to provide an improved extension mirror, for mounting over an existing mirror, particularly for use with doormounted existing mirrors having a fixed housing.

Accordingly the present invention provides a car extension mirror, assembly, for mounting over an existing mirror, comprising a mirror unit and strap means, the mirror unit comprising an elongated body having an adjustably mounted mirror at one end and having bracket means adjustably mounted on its top and bottom edges for abutment against the existing mirror, and the strap means being attachable to the bracket means to hold the mirror unit firmly against the existing mirror.

The bracket means preferably comprise four cranked brackets, mounted for movement vertically along respective slots, two at the top edge of the body and the other two symmetrically at the bottom edge of the body. The strap means may comprise any springy and extensible means, such as plastic encased elliptical coil spring means, but preferably comprise two elastic straps, each with two D rings for fitting over the ends of the brackets and with a 3-bar buckle for adjustment of its length.

The body may also carry a cranked rod, adjustably held to the body to rest against the car body or window glass adjacent to the existing mirror.

An extension mirror assembly in accordance with the invention will now be described, by way of example, with reference to the drawings, in which: Figure 1 is a general front view of the mirror unit; Figure 2 is a partial end sectional view, at larger scale, of a part of the assembly; Figure 3 is a side view, partly in section, of the mirror unit; and Figure 4 shows a strap forming another part of the assembly.

The assembly as a whole consists of a mirror unit and two straps. Figure 1 shows the mirror unit, the major component of which is a body 10 having a right-hand end 11 which carries four double-cranked brackets 12A to 12D, and a left-hand end 13 carrying a mirror 50, the two ends being connected together by two struts 14 also forming part of the body 10.

The four double-cranked brackets 12A to 12D are similar, and are similarly mounted in respective slots in the right-hand end 11 of the body 10. Figure 3 shows the body 10 from the side, with only the bracket 12D in place; the slot 24 is where the bracket 12C will be accommodated. Bracket 12A is shown on a larger scale in Figure 2, which also shows the details of its mounting in the body portion 11. The front edge of the body portion 11 is cut away to produce a slot 25, which communicates with a cut-away 45 at the rear side of the body portion 11. The bracket 1 2A consists of a strip of metal with a slot 26 formed in it at one end and bent in a double crank as shown at its other (outer) end, which has a protective plastic coating 27.The body portion 11 has a captive nut 29 mounted in a recess below and on the other side of the slot 25, as shown, and a bolt 28 passes through the slot 26 in the bracket 12A and engages with the nut 29. Thus by loosening the bolt 28, the bracket 12A is freed for adjustment in towards or out away from the body portion 11; and by tightening it, the bracket 12A can be fixed in any desired position.

The remaining three brackets 12B to 12D are similar. The body portion 11 has a plurality of cut outs 45, four of which accommodate the inner ends of the brackets 12A to 12D, with ribs 46 between them giving strength to the body portion 11.

The entire body 10 is preferably formed as a single unit of plastics material by injection moulding.

The outer end 13 of the body 10 is formed as a somewhat rounded cup shape in which the mirror 50 is held. More specifically, the mirror 50 is mounted on a plate 51 by means of adhesive pads 52. The plate 51 is attached to a ball 53 by means of a bolt 54, and the ball 53 is held in a spring spigot 55 which is bolted to the housing 13 by means of a bolt 56. The ball 53 and spigot 55 allow the position of the mirror 50 to be adjusted manually, by pressing on the edge of the mirror at the appropriate place, and the spigot 55 grips the ball 53 sufficiently firmly to hold the mirror 50 in position. If necessary, the mirror can be removed by tilting it to the maximum extent and inserting a lever behind it to force the ball 53 out of the spigot 55; it can be replaced by pushing it back, so pushing the ball 53 back into the spigot 55.Thus a convex mirror can be changed for a plane one or vice versa if desired. (The mirror can instead be removed by unscrewing the bolt 56.) The body portion 13 has formed thereon a stub 15 which carries a cranked rod 16, of the shape shown, with a plastic protective cap 17 at its tip.

The rod 16 is attached to the stub 15 by means of a clip 18 which is bolted to the stub 15 by means of a pair of bolts 19 engaging in captive nuts (not shown) in the stub 15. The rod 16 can be moved lengthwise relative to the body 10 by moving its left-hand end into or out of the body portion 13, and held in a selected position by tightening the bolts 19, so gripping the rod between the clip 18 and the stub 15.

The assembly also includes two similar strap units, one of which is shown in Figure 4. Each strap unit consists of a length of elastic strapping 35, a conventional 3-arm buckle 36 by means of which the length of the loop can be adjusted, and two D rings 37.

To attach the assembly to a car door mirror, the body 10 is placed with its right-hand end portion 11 against the existing car door mirror housing 40 over and in front of its glass side as seen in Figure 1. The brackets 12A to 12D are loosened, moved outwards to their full extent, and then moved inwards until their outer ends abut against the edges of the door mirror 40 (as shown for bracket 12A in Figure 2), and fixed in that position by tightening the bolts 28. The two straps 35 are then used to hold the body 10 firmly against the existing mirror housing, by being stretched between the ends of the brackets 12A to 12D by means of the D rings 37, as indicated in Figure 2. Preferably the straps are placed diagonally, so that one is stretched between brackets 12A and 12C and the other between brackets 12B and 12D.

The brackets 12A to 12D themselves abut against the edges of the existing mirror housing 40 but do not exert any appreciable holding force by themselves; at best, they merely hold the body 10 on the housing 40 while the straps 35 are being attached. This means that once the brackets 12A to 12D have been adjusted for a particular car, they can be left fixed in position while the extension mirror can be repeatedly taken off and reattached, so that the car can be used for towing and also on its own.

The rod 16 is intended to give rigidity to the mounting of the extension mirror, by being moved lengthwise through the stub 15 and rotated in the stub until its end 17 rests against the glass of the driver's door, or against the rubber seal at the bottom of that glass. The extension mirror obviously has a higher wind resistance than the existing mirror, and is liable to cause the existing mirror mounting to deflect at high speed. The rod 16 is highly effective at preventing this when used as described. The clip 18 is obviously tightened when the proper position for the rod 16 has been found.

This prevents any significant lengthwise movement of the rod through the stub 15. However, the leverage of the end of the rod 16 is high enough for it to be relatively easy to rotate the rod 16 in the stub 15, so that the rod can be rotated by hand to lie flat for easy storage of the extension mirror when it is taken off the car, and rotated back readily to its operative position when the extension mirror is refitted to the car.

It will be noted that all four brackets 12A to 12D are adjustable. This means that the assembly is symmetrical about the horizontal axis, and can therefore be used equally on either side of the car.

Obviously, if the brackets 12A and 12D, for example, were fixed, then the assembly would be high when used on one side of the car and low when used on the other. It is also necessary in practice to have at least two brackets on each side of the body 10. Only one bracket on each side would give only a 2-point mounting, which is obviously unstable; and the use of 3 brackets, though in principle it would give stability against twisting, would never-theless give a less firm mounting.

The straps 35 provide a degree of resilience to the mirror assembly, when mounted, against accidental knocks.

The rod 16 and the associated stub 15 are only necessary if the wind resistance of the extension mirror is high enough for deflection of the existing mirror housing 40 to occur. It may well be that the opening between the struts 14, which allows wind flow between the body portions 11 and 13, together with a suitable shaping of the body portion 13, will give a low enough wind resistance for the rod 16 and the stub 15 to be unnecessary.

Of course, there may be more than two struts 14 between the two body portions 11 and 13. A single further strut could easily be provided if the stub 15 and rod 16 are not provided. If the rod 16 is provided, then the provision of a third strut would preferably involve a slight redesign of the stub 15, so that it formed part of the third strut. Such redesign would involve forming stub 15 to lie below the left-hand end of the rod 16 instead of above it, as seen in Figure 3, so that the stub could continue across to the body portion 11 as a strut which leaving the left-hand end of the rod 16 low enough (as seen in Figure 3) to pass into the body portion 13.

The invention can of course be put into effect in other ways, one of which will now be briefly described. In place of the moulded plastic body 10, a metal plate is used, shaped like a rectangle with its left-hand end tapered. At the left-hand end, a mirror is mounted by means of a universal joint of the type used with wing-mounted mirrors, the universal joint being mounted directly on the plate. The plate has a pair of holes for the nuts, bolts, clip and rod corresponding to elements 15 to 19; the plate may have two such pairs of holes to allow for different placements of the rod. The four brackets are each singly cranked or Z shaped, and each has a mounting hole at its inner end. The plate has two opposite pairs of vertical slots, one pair near its right-hand end and the other at about its middle.

The brackets are bolted to the plate by means of the holes in the brackets and the slots in the plate, the slots allowing for the necessary adjustments.

Claims (6)

1. A car extension mirror assembly, for mounting over an existing mirror, comprising a mirror unit and strap means, the mirror unit comprising an elongated body having an adjustably mounted mirror at one end and having bracket means adjustably mounted on its top and bottom edges for abutment against the existing mirror, and the strap means being attachable to the bracket means to hold the mirror unit firmly against the existing mirror.

2. An assembly according to claim 1, wherein the strap means comprise springy and extensible means.

3. An assembly according to either previous claim, wherein the bracket means comprise four cranked brackets, mounted for movement vertically along respective slots, two in the top edge of the body and the other two symmetrically in the lower edge of the body.

4. An assembly according to claim 3 wherein the strap means comprise a pair of elastic straps, each with two D rings for fitting over the ends of the brackets and with a 3-bar buckle for adjustment of its length.

5. An assembly according to any previous claim, wherein the body carries a cranked rod, adjustably held to the body to rest against the car body or window glass adjacent to the existing mirror.

6. A car extension mirror assembly substantially as herein described and illustrated.