EXTERIOR REAR VIEW MIRROR

Abstract: The mirror comprises a support (22) adapted to be fixed to the body of the vehicle, a mirror housing (14) pivotally mounted on the support (22) for angular movement about a substantially vertical axis (20), first resilient detent means (24) located at a first radius from said axis (20) for retaining the mirror housing (14) in a first orientation and second resilient detent means (26) located at a second radius from said vertical axis (20) for retaining the said mirror housing (14) in a second orientation, the first and second radii differing from one another sufficiently to prevent interaction between the formations of the two detent means (24 and 26).

Description: Exterior Rear View Mirror This invention relates to an exterior rear view mirror for a vehicle of the kind in which the mirror orientation can be adjusted over a limited lateral range in normal use and which can move beyond such range so that the mirror folds back against the side of the vehicle in the event of impact, the mirror subsequently being returned to its previous position within its range of normal use. The invention is particularly but not exclusively applicable to remote controlled mirrors of the type in which the orientation of the mirror is adjustable relative to its housing and the entire housing is arranged to fold back in the event of impact. Such a mirror is commonly retained in its position of normal use by a spring-loaded detent device. In order to minimize wear on the interengaging detent surfaces, the detent device is so arranged that the mirror is held stationary when in its position of normal use and, when displaced therefrom, is free to move over sufficient range to fold to the side of the vehicle both forwardly and backwardly. Thus when the mirror is displaced by an impact, the interengaging detent surfaces rub over one another only during their initial movement out of engagement. In mirrors of the foregoing type, the limited range of lateral adjustment is usually less than the difference in required orientation between a mirror on the drivers s#ide of the vehicle and a mirror on the passengers side of the vehicle whichbeing further from the driver's head in the transverse direction of the vehicle, has to be oriented at a greater angle to such transverse direction than the mirror on the drivers side. Since left-hand and right-hand mirror housings differ from one another, four different versions of the mirror are required to provide for both left-hand drive and right-hand drive vehicles. According to the invention, an exterior rear view mirror comprises a support adapted to be fixed to the-body of the vehicle, a mirror housing pivotally mounted on the support for angular movement about a substantially vertical axis, first resilient detent means located at a first radius from said axis for retaining the mirror housing in a first orientation and second resilient detent means located at a second radius from said vertical axis for retaining the said mirror housing in a second orientation, the first and second radii differing from one another sufficiently to prevent interaction between the formations of the two detent means. In one form of the invention each detent means comprises a single tooth projecting from one of the support and the housing and a pair of such tooth projecting from the other, so as to embrace the first mentioned teeth when the housing is in its position of normal use relative to the support. When the first mentioned tooth is clear of the other two t eth, it is free to move without interference. In order to obtain additional stability, up to three such confronting first teeth and pairs of second teeth may be uniformly spaced around the substantially vertical axis. Where there are three such sets spaced 0 at 120 to one another, teeth of one set will not reach the teeth of an adjacent set during normal use because the range of travel as a result of impact is approximately - 90 from its position of normal use to abutment with the side of the vehicle. An embodiment of the invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a partially broken away side view of a mirror in accordance with the invention; Figure 2 is a plan view of the support of Figure 1 after removal of the mirror housing, and Figure 3 is a fragmentary cross-sectional view taken on the line 3-3 in Figure 2 and also showing the adjacent part of the mirror housing. Referring to the drawing, the mirror 10 is mounted on a base plate 12 within a housing 14, the base plate being coupled to means for adjusting the orientation of the mirror 10 relative to the housing 14 by universal joints 16. A sleeve 18 projects downwardly from the bottom of the housing 14 so as to embrace a stem 20 projecting upwardly from a support 22 which is adapted to be secured to a part of a motor vehicle for example, the driver's or front passenger's door. The bottom of the stem 20 is surrounded by two concentr#e toothed tracks 24 and 26. As can be seen from Figure 2, the tract 0 22 has three triangular teeth 28, 30 and 32 spaced at 120 to one another with flat troughed zones between the teeth. The outer track 26 also has three triangular teeth 34, 36 and 38 spaced at 0 120 to one another but offset with respect to the corresponding 0 teeth 28, 30 and 32 of the inner track by about 15 . As with the inner track, the troughs between the teeth 34, 36 and 32 of the outer track are flat. The bottom end of the stem 20 has corresponding inner and outer tracks 40 and 42. As can be seen from Figure 3 the track 40 has a pair of teeth 44 and 46 with a triangular trough therebetween in which the tooth 28 on the track 22 can be received. The track 40 has similar pairs of teeth (not shown) spaced at 1200 to one another so as to engage with the teeth 30 and 32 simultaneously with the engagement of the teeth 44 and 46 with the tooth 28. The outer track 42 on the stem 18 also has three pairs of teeth spaced at 1200 to one another, each having a triangular trough therebetween for engagement with the teeth 34, 36 and 38 on outer track 24 and base. However, the pairs of teeth on the outer track 42 on the stem 18 are aligned with the pairs of teeth on the inner track 40 thereon so that the orientation of the mirror housing 14 with respect to the support 22 at which the teeth of the outer tracks 24 and 42 engage with one another, is offset by about 150 with respect to that at which the teeth of the inner tracks 22 and 40 engage with one another. Reverting to Figure 1, in order to hold the housing 14 on the support 22 with the tracks 24, 40 and 26, 42 in engagement with one another, a compression spring 48 is located between a washer 50 which engages under a shoulder 52 on the top of the stem 20, and an inwardly directed shoulder 54 on the stem 18 above the inner track 22. Thus when the mirror housing 14 is in an orientation such that the teeth of say the inner tracks 24 and 40 are in engagement with one another these teeth are resiliently held in such engagement, but if sufficient force is applied to the housing 14 such teeth can become disengaged. If the force is in one direction, the 0 mirror housing moves initially through about 15 so as to bring the teeth on the outer tracks 26 and 47 into alignment. If the force continues, the teeth of the outer tracks 26 and 42 become disengaged and the mirror housing 14 is then free to move through 0 about 100 (unless it collides with a part of the vehicle on which it is mounted before its range of movement has been completed). If the force is applied in the other direction the mirror housing 14 is immediately displaced into a position in which such free movement is permitted. It will be appreciated from the foregoing that during each occasion on which the mirror housing is displaced from its orientation of normal use, each of the teeth of the tracks 24, 26 and 40, 42 is subject to impact and/or abrasion on one occasion only, while the provision of the two separate offset tracks provides the mirror housing 14 with two alternative positions of normal use, thus catering for both right-hand drive and left-hand drive vehicles.

Claims: CLAIMS 1. An exterior rear view mirror comprising a support (22) adapted to be fixed to the body of the vehicle, a mirror housing (14) pivotally mounted on the support (22) for angular movement about a substantially vertical axis (20), and first resilient detent means (26) located at a second radius from said vertical axis (2cj for retaining the said mirror housing (14) in a second orientation, the first and second radii differing from one another sufficiently to prevent interaction between the formations of the two detent means (24 and 26). 2. A mirror according to claim 1, characterised in that each detent means (24, 26) comprises a single tooth (28) projecting from one of the support and the housing and a pair of such teeth (44, 46) projecting from the other, so as to embrace the first mentioned tooth (28) when the housing (14) is in its position of normal use relative to the support (22), means (48) being provided for resiliently urging the housing (14) and the support (22) towards each other. 3. A mirror according to claim 2, characterised in that sets of first teeth (28, 30, 32) and pairs of second teeth (44, 46) are uniformly spaced around the substantially vertical axis (20).

Inventors: BODDY, IAN
Applicants: BRITAX (WINGARD) LIMITED
Application year: 1982
Main classification: B60R1
IPC codes: B60R1