The present invention concerns a mirror assembly for a vehicle, in particular for a commercial vehicle.
The support arm of rearview mirrors in commercial vehicles, like a city bus, is commonly extended forward from the chassis at an essentially horizontal level when the mirror head hangs downward from the forward end of a support arm, they are known as “horn-mirrors,” especially when applied to buses. Horn-mirrors provide better aerodynamics and simple fabrication as well as an advantageous field of view which encompasses a wide arc.
If, as in the case of “low-floor” buses, a part of the support arm and/or the mirror extend into a safety zone, this zone normally covers a span from the ground level to about 2 meters above, the mirror must be adjusted as to height for the protection of both mirror and persons as may be waiting within a said safety zone.
EP 0 895 897 B1 proposes a single hinge attachment so that the mirror can be swiveled about a single horizontal axis, transverse to the direction of vehicle travel to move from its operational position in which the mirror is at least partially within the limits of the safety zone. Following the swiveling, the mirror would find itself in a position of no harm, and above the safety zone limits.
Since the mirror presents a danger of impact, both in forward and reverse travel, it becomes necessary, that the hinge of EP 0 895 897 B1 be capable of swinging in two directions of rotation, in order to protect persons in the safety zone from severe mirror impact. For example, upon a bus start-up from a bus-stop or during a backward maneuver. Likewise, the mirror must remain fixed in position of operation during normal travel, even when subjected at times to shaking and to strong wind forces. In such a case, EP 0 895 897 B1 proposes the use of friction fittings.
Hinges which permit swinging in both directions, and enable a simultaneous attainment of a fixed position are expensive.
Accordingly, an object of the present invention is to enable a stable securement of a vehicle mirror in its operational position and, at the same time, to assure a pivoting about an axis allowing two directions of rotation.
The construction designed to carry out the invention will hereinafter be described, together with other features thereof.
The above objective is accomplished in accordance with the present invention by providing a mirror assembly having a support arm, a mirror head, and two hinges connecting the support arm and the mirror head. The first hinge allows a pivoting of the mirror head about its axle of rotation only in one direction, and the second hinge permits a pivoting of the mirror head about its axle of rotation only in a second direction of rotation, which is opposite to the first. Preferably, each hinge pivots only in one direction. In this way, the construction of both hinges is less complex. The first and/or second hinge may incorporate a detent which limits rotation in either the first or the second direction. Such a detent can, for example, be made mechanically or be provided with a friction fit. Thus, a desired second detent can also be the detent inherent in the other hinge arrangement. The large lever arms, which result therefrom, assure, with relatively small support forces, sufficiently high resistance torques. In this way, completion of a pivoting opposite to the allowable direction of turning is provided. By means of limiting the turning motion to only one direction, it is advantageously possible to fix the mirror head satisfactorily in its operational position, since in these two hinges, in the respective direction, high forces are accepted.
The first and/or second hinge can include a torsion spring. The springs, in a constructive, simple, and economical manner provide a pivoting in the allowable direction and otherwise affix the mirror head securely in its operational position. Further, the springs allow the mirror head to return accurately to its operational position following a safety displacement.
In a particularly advantageous embodiment, upon a pivoting of the mirror head about the axis of one hinge, the hinge connection between the mirror head and the carrier arm is released. In this way, for example, the axis of the first hinge prevents a further pivoting about the axis of the second hinge counter to the second rotational direction beyond the limited operational positioning. In the case of a pivoting in the second rotational direction, to the contrary, the connection of the first hinge releases itself.
In a preferable manner, the support arm and/or the head of the mirror can be enhanced with a bearing structure, preferably of metal construction. If this is coated, for example, with a material, such as plastic, and the coating can be applied by spraying, the result is a light, aerodynamically favorable, and uniformly stable assembly of the mirror, and vibration of the mirror is reduced. Particularly preferable, the first and/or the second hinge can be hingedly and reliably attached to this structure.
In another advantageous embodiment, the support arm comprises a first and a second part. Between the said first and second support arm part, a third hinge is present, the axis of rotation of which extends itself vertically during the mounting of the mirror. This allows an additional pivot direction of the mirror assembly to the side or to the front of the vehicle. The overall dimensioning allows an advantageous reduction of length for, as an example, loading on a ship, parking, or the like. This extra pivoting can be effected by a motor, or may be manual.
The mirror head is usually an elongated structure having a first end of the mirror head pointing towards the vehicle and a second end pointing away from the vehicle. According to a preferred embodiment of the invention either the first or second hinge is attached to the mirror head at a position between the first end of the mirror head and the second end of the mirror head. This arrangement reduces the space required for the mirror head upon pivoting. Due to this placement of the hinges, the mirror head acts, in the case of a pivoting in the first direction of rotation, a weight compensation and generates an inherent torque about the first axle of rotation because of gravity. In this manner a pivoting in the first direction of rotation at the constructively identical first and second hinges requires a lesser release torque. Therefore, the first hinge is already released upon small torques, while the second hinge is only released at higher torques, and thus withstands torques induced by wind forces, for example.
The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown and wherein:
Referring now in more detail to the drawings, the invention will now be described in more detail.
As is shown in
The support arm 1 encompasses a bearing structure 14, preferably made of metal and an aerodynamic coating 13, preferably of plastic. The support arm, as can best be seen in
The mirror head 2 includes a carrier arm 24 (
As can best be seen in
Hinges 3, 4 include, respectively, a torsion spring, for example, possibly a characteristically shaped steel spring. The end of the spring is rigidly fixed to the carrier arm and its second end attached at frictionally engaged mirror head 2 on carrier arm 24. In this way, a resistance to the pivoting is provided. In a similar manner, the spring can be fixed rigidly with the carrier arm 24 of the mirror head 2 and support itself in snapped-in mirror head 2 on carrier arm 24 of the support arm 14.
A detent 44 provides a mechanism by which carrier arm 24 temporarily stays in place relative to the hinge until it is released by force. For this purpose, hinge slot 46 narrows to a throat 48 reduced in comparison to axles 31, 41, so that the axles snap in and out of the throat. While snapped in the throat, the axles are frictionally gripped and held in place until released by snapping out.
Besides the friction engagement of the mirror head 2, the two springs also fix the mirror head in its operating position. Since the axle rotation of the respective other hinge, acting as part of the detent, prevents a pivoting counter to the desired direction of rotation, it is possible that the hinge can be constructed very simply and robustly by means of the springs. As a whole, the coaction of the two hinges 3, 4, the torsion springs, which provide resistance to undesired pivoting, the axles 31,41 of rotation, which function as a detent, and the self-engaged locking of the axle 31, 41 of rotation, enables a constructively simple and secure fixation of the mirror head 2 in its operational position. Nevertheless the mirror head 2 can be released from this position by an impact due to collision, after which the mirror head assumes one of its alternate positions.
If a collision with an obstruction (for example in a case of maneuvering in reverse gear) exerts a sufficiently large directed force against the mirror head 2, (
If the above action is reversed and a collision with an obstruction upon a forward moving of the bus (for instance upon the startup from a bus station) exerts a substantial rearward directed force against the mirror head 2 (
In the described embodiments of the invention mirror head 2 is an elongated structure and in operational position of the mirror assembly has a first end 15a pointing towards the vehicle and a second end 15b pointing away from the vehicle. First hinge 3 is attached to a mirror head 2 between first and second ends 15a, 15b of the mirror head. The second hinge 4 is attached to first end of the mirror head 2. Due to this placement of the hinges 3, 4, mirror head 2 and carrier arm 24, respectively, acts as a weight compensation and generate inherent torque about the first axle 31 of rotation, in the case of a pivoting in the first direction of rotation A. In this manner, pivoting in first direction of rotation A at constructively equal first and second hinge 3, 4, requires a lesser release torque. It is possible that first and second hinges 3, 4 can advantageously be built like one another, so that first hinge 3 is already released upon small torques, while second hinge 4 only releases at higher torques, and thus withstands, e. g., torques induced by wind forces.
The design of releasable fastenings in hinges 3, 4, themselves, is very simple due to the shape-fit and the one-way releasing support of the springs, which is kinematical and design wise very simple. Alternately, however, even mirror head 2 can be built as a two-piece structure, wherein the both parts can commonly be pivoted around second hinge 4 and only a forward part can rotate about first hinge 3. If one examines
While a preferred embodiment of the invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.
Number | Date | Country | Kind |
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102005023711.8 | May 2005 | DE | national |