The present invention relates to a holding arm for an external motor vehicle mirror with an integrated swivel articulation capable of snapping in in at least one position.
A mirror arm mechanism of this type is known from EP 0 641 686 A2. With the swivel articulation shown there, the different snap-in elements are subjected to the force of a helicoidal screw spring in the direction of engagement of the snap-in mechanism. The embodiments shown therein have in common that different axially and radially acting wedge surfaces intermesh on rings or ring segment elements seated within each other in a relatively complex manner. To this extent the known swivel articulation is of complicated design and its assembly is expensive. Furthermore with the known swivel articulation, especially with an embodiment in which different separate ring segments are used to constitute snap-in wedge surfaces, the snap-elements can jam with each other. This would block the swivel articulation which could no longer carry out its safety function, i.e. swiveling back when the external mirror supported by the holding arm impacts an obstacle. Due to blocking or at least due to the sluggishness caused by the interaction of the various internal parts of the swivelling articulation, the manual swiveling of the mirror, e.g. to pass narrow passages, is rendered more difficult.
With respect to the state of the art it should be pointed out as a general background that with such holding arms with snap-in swivel articulation, articulation designs are often used where the arm segments emanating from the swiveling articulation are offset relative to each other during snapping in and out of the swiveling articulation. This offset has been compensated for in the past by the elasticity of holding arms of considerable length.
Modern, up-to-date mirror designs often have only very short holding arms however, which extend directly in horizontal direction from the vehicle body to the mirror housing. Especially with these designs, the clearance for length compensation is very limited. One solution of this problem is already provided by the above-mentioned EP 0 641 686 A2, however with the above-mentioned disadvantages.