Foldable vehicle outside rearview mirror having a detachable cap

Disclosed is an outside rearview mirror for a vehicle which has a mirror base adapted to be mounted to a car body, and a mirror housing mounted to a support plate. The support plate is fastened foldably to the mirror base by a joint. The mirror housing has the form of a frame surrounding a mirror glass which is mounted by an adjustment device to the rearward face of the support plate. A cap is detachably clamped to the front face of the support plate and continues the outer contour of the mirror housing. Thereby the transfer of vibrations from the mirror housing to the mirror glass is cut down to a minimum and shifted to a frequency range which does not influence the perception of the image the mirror glass is presenting to the driver of the car.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention refers to an outside rearview mirror for a vehicle, which has 
a mirror base adapted to be mounted to a car body, and which has a mirror 
housing foldable about the mirror base. 
2. Description of the Related Art 
German Utility Model Specification 82 36 870 discloses an outside rearview 
mirror having a mirror housing to the front portion of which a cap is 
detachably clamped. The mirror housing may be made of black plastic 
material whereas the cap may be colored as desired. The cap which has to 
be clamped strongly to the mirror housing, however, modifies the 
vibrational characteristic of the unit comprising mirror housing and cap 
to the effect that under certain conditions vibrations of the car body are 
transferred to the mirror glass through said unit. 
German Patent Specification 28 13 316 discloses an outside rearview mirror 
wherein a support plate is strongly coupled to a joint connecting foldably 
the mirror housing to the mirror base. The mirror housing is mounted to 
the support plate by a number of posts which are spaced for minimizing the 
transfer of vibrations from the mirror housing to the mirror glass 
supported by the support plate. If the mirror housing of such an outside 
rearview mirror is equipped with a detachabled cap, the mirror glass tends 
to vibrate under special driving conditions of the car. 
SUMMARY OF THE INVENTION 
It is therefore an object of the invention to devise an outside rearview 
mirror the mirror glass of which has improved vibrational characteristics 
over substantially all driving conditions of the car. 
According to the invention an outside rearview mirror for a vehicle is 
provided with a mirror base adapted to be mounted to the car body, and 
with a mirror housing foldably connected to the mirror base. The mirror 
housing is mounted to one side of a support plate, and a mirror glass is 
mounted to the opposite side of the support plate. The mirror housing 
forms a frame, which leaves free a front portion of the support plate. 
That portion is covered by a cap which is detachably clamped to the 
support plate. Thereby a substantial reduction of the mass of the mirror 
housing is obtained which shifts the natural frequency thereof into a 
frequency range which has no noticable influence on the perception of the 
image offered by the mirror glass to the driver of the car. Moreover, 
vibrations of the cap which are prevented from interacting with those of 
the mirror housing have a sufficiently high natural frequency and 
therefore have also no noticable influence on the perception of the image 
produced by the mirror glass. The invention allows a substantial reduction 
of the space behind the mirror glass which adds to an improved vibrational 
characteristic in the low frequency range. Specifically when running the 
car very fast vibrations of the mirror glass are reduced to an unnoticable 
minimum. 
According to a preferred embodiment of the invention a plurality of 
radially resilient posts project from the bottom of the cap which may 
clamp behind edges e.g. of openings formed in the support plate. This 
allows easy mounting of the cap to the support plate and disengaging of 
the cap from the support plate in case of repair or replacement. 
Preferrably, the cap may additionally be coupled to a portion of the 
mirror housing which does not undergo any substantial vibrations and which 
is normally adjacent the mirror base. To this end it is preferred that one 
or more elastic fingers are formed from that portion of the mirror housing 
which may clamp behind shoulders or edges of the cap. 
It is specifically preferred to couple foldably an extension of the support 
plate to the mirror base by a joint. The frame of the mirror housing then 
may be provided with a continuous web by which the frame is fastened to 
the support plate.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The outside rearview mirror designated generally by the reference numeral 1 
includes a mirror base 2 adapted to be mounted to the left driver door of 
a car. An arm 9 projects from the mirror base 2 upon which an extension 10 
of support plate 3 is mounted foldably by a tubular rivet according to 
German Patent Specification 28 13 316 the contents of which is included 
herein by reference. Thus, the support plate 3 is foldable about a 
substantially vertical axis of the tubular rivet 75 relative to the mirror 
base when the latter is mounted to the car body. A mirror glass 5 is 
bonded to carrier plate 6 which is mounted to a rearward face of the 
support plate 3 by an adjusting device 8 for adjusting the angular 
position of the mirror glass 5 within a mirror housing 4. Both the mirror 
housing 4 and a cap 7 are mounted to the support plate 3. The cap 7 fits 
into an outcut of the mirror housing 4 and covers a front portion of the 
support plate 3 which otherwise would be free accessible from the front 
side through the outcut. 
The support plate 3 is made of metal and has a generally rectangular form 
and is strengthened by beads or similar impressions. The armlike extension 
10 protects laterally from a lower portion of the support plate 3 and has 
a through bore 12 through which the tubular rivet may extend for mounting 
foldably the support plate 3 to the arm 9 of the mirror base 2. Four 
rectangular openings 13, 14, 15, 16 are provided in the support plate 3, 
each opening being arranged in the vicinity of one of the rounded corners 
of the support plate 3. Each opening 13 . . . 16 has two opposite edges 
like 17 and 18 which are strengthened for holding noses at free ends of 
one of radially elastic posts. The support plate 3 moreover has four 
threaded bores 20, 21, 22, 23 close to its periphery 24. The openings 13, 
14, 15, 16 and the threaded bores 20, 21, 22, 23 are aranged around a 
central portion 25 of the support plate 3 upon which the adjusting device 
8 bearing the mirror glass 5 may be mounted. 
The mirror housing 4 is formed from shock resistant plastic material and 
comprises a continuous web 26, 27 surrounding a central opening. The web 
26, 27 is provided with four through bores which are arranged in relation 
to the threaded bores 20, 21, 22, 23. Thereby the mirror housing 4 may be 
mounted to the support plate 3 by four screws each extending through one 
of said openings and engaging into one of the threaded bores. The web 26, 
27 is formed from a continuous wall section 28, 29 of the mirror housing 4 
which surrounds the mirror glass 5 in spaced relationship when the mirror 
housing 4 and the mirror glass 5 each are mounted to the support plate 3. 
The wall section 28, 29 is bent forwardly for forming a marginal 
enlargement 30, 31 the free edge of which is diminished for forming a 
shoulder 32. As may be seen from FIG. 2 the free edge of the enlargement 
is substantially flush to the plane of the mirror glass 5 when the mirror 
glass 5 assumes an intermediate position of its angular range of 
adjustment. Thereby, the complete front face 60 of the support plate 3 is 
free accessable from a direction as shown by arrow 65. 
The cap 7 may be formed from the same material as the mirror housing and 
coninues the latter for forming a continuous outer surface of the outside 
rearview mirror of a common shape. Four radially resilient posts project 
from the bottom surface 33 of cap 7. Only the posts 34, 35, 36 are shown 
in FIGS. 2 and 5. The posts are arranged in the bottom surface 33 so as to 
conform with the positions of the openings 13, 14, 15, 16 of the support 
plate 3. Each of the posts comprises a pair of resilient, parallel and 
closely spaced fingers like fingers 37, 38 of post 34. The free end of 
each finger 37, 38 is formed to a catch nose 41, 43 such that each one of 
the noses 41, 43 may clamp behind the related edge of the openings 13, 14, 
15, 16 like opposite edges 17, 18 of opening 14 for clamping the cap 7 to 
the support plate 3. Moreover, cap 7 has a continuous inwardly offset 
marginal web 40 which engages below the diminished marginal web of the 
mirror housing 4 at shoulder 32 when cap 7 is clamped to the support plate 
3. As may be seen from FIG. 2 the posts such as posts 34 and 35 are of 
different lengths for spanning the space between the bulged form of the 
cap 7 and the stepped form of support plate 3. 
Another pair of spaced, elastic fingers (not shown) is formed from that 
portion 31 of the marginal enlargement which is adjacent to the mirror 
base. Each finger has a laterally protecting nose at its free end. A wall 
section 58 of cap 7 adjacent to the mirror base is provided with two edges 
54, 56 as parts of openings 50, 52. Therefore, the noses of the spaced 
fingers may snap behind edges 54, 56 for additionally mounting and holding 
cap 7. 
For assembling the outside rearview mirror according to the invention the 
cap 7 is clamped to the front side of support plate 3 when the laterally 
extending noses of the posts penetrate and snap behind the openings 13, 
14, 15, 16. When the cap 7 is so clamped the marginal web 40 engages the 
margin of the mirror housing 4 so that the form of cap 7 continues the 
form of the rudimentary mirror housing 4. When clamping cap 7 to support 
plate 3, the spaced fingers lock resiliently behind edges 54, 56. If 
repair or replacement of the cap 7 is desired, it may be detached from 
support plate 3 by bending each pair of fingers 37, 38 towards one 
another, so that noses 41, 43 are released from the edges 17 and 18 of 
openings 13, 14, 15, 16 and the cap may be removed thereby disengaging the 
spaced fingers from edges 54 and 56. 
The support plate 3 is vibration-free mounted to the mirror base 2 and 
suppresses any vibrations in view of its beads and impressions. The 
extension of the support plate 3 corresponds approximately to that one of 
the mirror glass 5. Thus, the mirror housing 4 is only a kind of bordering 
for the mirror glass 5. The expanding arbors are arranged in areas where 
vibrations nodes or at least reduced vibration amplitudes of the cap 7 are 
found. Thereby, any vibrations of the cap 7 will not influence the 
perception of the image the mirror glass is presenting to the driver of 
the car. 
As an option, the cap may be coloured differently than the mirror housing.