Patent Application
20120002310
The present invention relates to a rotatable mirror holder for automotive vehicle mirrors, in particular for utility vehicles, and a mirror assembly having said mirror holder.
Conventional mirror holders are usually made up of two component parts, namely, a vehicle-side holder which is adapted to be connected to the vehicle, and a mirror-side holder which establishes the connection to the respective mirrors. Both connection components have corresponding connection surfaces at which they are connected to each other. In accordance with the prior art, the connection components are mostly connected by a threaded connection while partly also being secured with the aid of a so-called quick-lock. The axis of the threaded connection at the same time defines the rotation axis of the two parts. In order to secure the most constant frictional force possible, a disk spring is generally underlain, or a compression spring for further reducing the tolerance influences.
Owing to the multiplicity of the components required for this purpose, such as bolt, nut, disk springs etc., not only the manufacture but also the assembly of such a mirror holder is complex and expensive. The demands to a constant frictional force as well as the demand for a stable and thus low-vibration mirror holder results in a demand for low tolerances of all components involved and an assembling process in which the manufacturing parameters are continuously adapted to the variations by way of controls. This causes the manufacturing costs to rise. Moreover, a greater number of single parts generally brings about higher logistical expenditure, e.g. with regard to stocking.
It is therefore an object of the present invention to furnish a mirror holder for an automotive vehicle mirror which may on the one hand be produced at minimum expenditure and low cost, and on the other hand provides a stable and lasting functional rotary connection between vehicle and mirror.
With regard to the holder, this object is achieved through the features of claim 1, and with regard to the mirror assembly through the features of claim 18.
In the mirror holder of the invention, the first connection component comprises a bolt having a rotationally symmetrical jacket surface. The second connection component comprises a sleeve encircling the bolt and having an inner jacket surface formed complementarily with the jacket surface of the bolt, wherein one of the bolt and the sleeve comprises at least one engagement element which is engaged in a complementarily shaped retaining member in the sleeve or the bolt, thus blocking a displacement of the two connection components in the direction of the rotation axis.
Due to he interlocking relation of engagement element and retaining member, the two connection components are connected to each other with form-fit and only admit a rotation about the rotation axis. On the one hand, the bolt is fixed radially and centered in the sleeve, and on the other hand the bolt is fixed axially in the sleeve. This form-fit moreover does away with the necessity of a threaded connection etc. for fixation of the two connection components, so that material and assembling costs may be saved and the overall costs of the mirror holder may be reduced. Faulty assembly can moreover not occur any more due to the omission of an assembling process.
In a preferred manner, sleeve and bolt comprise complementarily shaped first and second locking surfaces. The provision of locking surfaces on the one hand allows to define certain relative angles between the two connection components, while on the other hand this may be utilized to set a certain threshold value for the fold-in force of the mirror. While the fold-in force must be high enough for the mirror to resist external forces during normal usage, such as wind resistance, it must nevertheless be adjustable by the driver or allow the mirror to yield under extraordinary force influences for safety reasons.
In accordance with claim 3, the two locking surfaces are formed on the jacket surfaces of bolt and sleeve. This allows an adjustment of the rotational resistance by way of the wall thickness of the sleeve. If the wall thickness of the sleeve is low, the latter yields in a radial outside direction when the bolt is rotated. Apart from this, the locking force is determined by the shape of the locking mechanism having the form of a flattening, shaft etc., and by the locking depth.
In accordance with claim 4, the two locking surfaces are provided on the end face of the bolt and on the bottom inside the sleeve. As the axial displacement of the two connection components is blocked by engagement element and holding member, the end faces of the bolt and the sleeve bottom are biased relative to each other, as it were, so that the locking surfaces engage each other. At a corresponding configuration of engagement element and holding member it is possible to establish a locking function involving a lower locking force as compared with the previous variant.
If the rotation axis is formed transversely to the longitudinal axis from the first and/or second connection component, the mirror holder of the invention represents a hinge joint. The mirror holder of the invention thus allows not only a rotation of two connection components on a rotation axis but also a pivotal movement of one connection component about this rotation axis. The mirror holder of the invention thus represents a flexible connection and is not limited to any screw axes of threaded connections.
In a preferred manner, the sleeve is an injection-molded part of a first plastic material. This aspect provides a number of advantages. For one thing, the entire mirror holder may be produced in a very simple manner by injection coating of the second connection component on the first connection component. Injection coating of the plastic material at the same time achieves a connection between sleeve and bolt that is virtually free of play. Shrinkage of the sleeve during curing of the plastic material even produces a radial force acting on the bolt, so that the radial force of the sleeve acting on the bolt, i.e., the fold-in force of the mirror, may even be adjusted through selection of the plastic material.
In selecting the plastic material it is necessary to preclude the connection components adapted for relative pivoting from being bonded or fused during injection molding. As the sleeve is injection-coated on the jacket surface of the bolt and complementarily adapts the shape of the inner jacket surface of the sleeve to the jacket surface of the bolt, manufacturing inaccuracies during manufacture of the bolt do not have any effects on the functionality of the rotary connection. Such inaccuracies are simply compensated by injection molding. This adaptation also allows to obtain a very low-vibration mirror holder.
As mirror holders are manufactured at high piece numbers, this manufacturing method results in enormous cost savings which outweigh the manufacture of the injection molding tool by far. Injection molding of the sleeve always allows to produce a complementary jacket surface of the sleeve even for bolt jacket surfaces having a complex shape, so that the form-fit of the mirror holder will lastly already be defined through the configuration of the bolt.
Due to injection molding of the sleeve a non-releasable connection between first and second connection components is achieved, whereby a stable and permanently connected rotary connection between two connection components is obtained which does not require maintenance throughout its entire service life.
In a preferred manner not only the sleeve but also the bolt is an injection-molded part, which then consists of a second plastic material having a higher melting point than the first plastic material. The mirror holder may be produced by the so-called in-mold assembly process. In this case a first connection component is produced in the basic process type. This may be either a plastic material component or a die-cast component or some other component. In a second process step this first connection component is inserted in the tool for the manufacture of the second connection component, with the sleeve encircling the bolt on account of the advantageous realization by the manufacturing process. If the first component is also realized of plastic material, this allows to manufacture the mirror holder in a single manufacturing process including single process steps, whereby the manufacturing costs may be reduced further. The two plastic material types should be selected such that the plastic bolt will not be melted when the sleeve is injection-molded on it. Moreover it is possible to adjust the relative frictional and/or locking forces of the two connection components via the combination of the two kinds of plastic material.
In order to ensure mobility of the two connection components, it is necessary to make sure that during the manufacture of the second connection component the plastic material thereof does not enter a surface connection with the material of the first connection component. To this end it is necessary for the melting temperature of the first material to be higher than the temperature of the second material at the time when the second material contacts the first material. If the manufacturing parameters are selected appropriately, it is possible to produce both parts of a same material. It is, however, particularly advantageous if the two materials are of a different kind while having only a very low tendency, even in the plastic condition, to melt together, wherein the material of the first connection component should have a higher temperature stability.
Mobility of the two connection components may also be achieved by selecting two kinds of plastic material that are not compatible with each other and do not adhere to each other. This allows nearly simultaneous injection molding of the two connection components.
Advantageously, the retaining member is a continuous groove in the jacket surface of bolt or sleeve. Such an annular groove may be produced in a very simple manner and allows on the one hand a rotary movement of the complementary connection component about the rotation axis while on the other hand preventing a relative displacement of the two parts in the direction of the rotation axis. This groove forms an undercut.
Advantageously, the engagement element is a—preferably also continuous—protrusion which is engaged in the groove. Engagement element and retaining member thus establish a form-fit in the direction of the rotation axis.
If the first and second locking surfaces are provided in the groove or on the protrusion, respectively, it is possible to produce both the axial fixation and the immobilization of the two connection components in the peripheral direction in one production step.
Configuring the bolt in the shape of a partial sphere is equally simple and effective. Just like the combination of groove and protrusion, this allows to obtain a form-fit that securely prevents a displacement of the connection components and admits the free rotary movement. Where the sleeve covers the part of the spherical shape exclusively, this advantageous configuration allows to obtain a wide degree of freedom insofar as the second connection component can be moved not only about the rotation axis relative to the first connection component but also in a small angular range about the sphere's center. As a result, a flexible utilization of the same mirror holder at different positions of the mirror head and of the rotation axis of the mirror system is possible.
As was already mentioned in the foregoing, the mirror holder of the invention may be produced in a very simple way by an in-mold assembly process. Here, the first injection-molded part is produced in a first mold and subsequently introduced into a second mold and injection coated by the second injection molding material. Optionally, the first injection-molded part remains in the first mold, with merely another cavity having the shape of the second injection-molded part being released. The first injection-molded part represents, as it were, the insert for the second injection-molded part. This is also referred to as a so-called pre-molded part. In this way it is possible to obtain a variety of tightly fitting connection surfaces of the two connection components which admit a relative movement of the two connection components while, however, preventing an axial displacement.
The two connection components of the mirror holder of the invention are preferably connected to each other in a non-releasable manner so that the connection can not become loose by itself.
Advantageously, the bolt and the sleeve are each formed integrally, whereby the number of connection components is reduced to a minimum.
The subject matter of claim 20 is a mirror assembly comprising at least one mirror holder in accordance with one of the aspects mentioned in the foregoing.
The mirror assembly 2 shown in
This rotary connection may be produced in a very simple manner by the so-called in-mold assembly process, also in a single injection molding tool, wherein the individual injection-molded parts need not be assembled with each other but are cured inside each other. Alternatively, the connection component 10 comprising the bolt 14 may also be made of any other material, also of metal, onto which a plastic material is injection-coated in order to realize the sleeve 16. In the selection of the materials used care should be taken, however, that these will not connect or adhere to each other in the manufacturing process, so as to achieve the desired rotary mobility of the two connection components relative to each other. In the manufacture of the two connection components it is therefore advisable to only use plastic material types that are not compatible with each other. The rotary mobility may in particular be obtained in that the connection component comprising the bolt and injection-molded first consists of a plastic material having a higher melting point than the second connection component which is molded onto the first connection component in a subsequent step.
On account of injection coating of the one connection component onto the other one, the tolerance of the components with regard to their size is insignificant, for the sleeve in the second connection component inevitably assumes the size of the bolt of the first connection component. A play-free connection at high fitting quality that satisfies highest requirements to the vibrational comportment is thus achieved without any undue process requirements.
As the injection-coated sleeve 16 closely follows the jacket surface 18 of the bolt 14 and undergoes some shrinkage during curing, a radial force from the sleeve 16 onto the bolt 14 is generated, so that a certain rotating force is necessary for rotating the two connection components 10 and 12 relative to each other. This frictional force between bolt 14 and sleeve 16 thus defines a fold-in force which is created as early as during the manufacturing process of the mirror holder and on the one hand withstands usual external forces, such as wind resistance, while on the other hand—if so desired—admitting a relative rotation of the two connection components. This fold-in force may be adjusted through selection of the different material combinations.
Another parameter for the adjustment of the rotational mobility of the two connection components 10 and 12 is represented by the wall thickness D of the sleeve 16. As a more or less rigid construction is obtained depending on the wall thickness, the frictional forces between sleeve 16 and bolt 14 thus increase or decrease accordingly. Moreover the bolt portion 14, as shown in
Other than in the representation of
While
As was already mentioned,
Similarly to the first embodiment, the mirror-side connection component 12 comprises a sleeve 16 which encircles a bolt 14 of the vehicle-side connection component 10. An end portion of the vehicle-side connection component 10 includes a fastening portion 26 which may be clamped fast in different rotary positions about the screw axis on a corresponding counterpart on the vehicle via a threaded connection. The mirror-side connection component 12 includes a bore 28 for coupling of the mirror housing.
Axial fixation of the two connection components 10 and 12 may be realized in various manners, as is shown by way of example in
It should be noted that for reasons of clarity, the connections of bolt 14 and sleeve 16 in
In
A traditional carrier for a utility vehicle mirror is formed of a metal pipe. Coupling to the connection member takes place inside a pipe sleeve. The usual pipe configuration assumes the shape of a “U”, with an upper and a lower arm thus representing the coupling to the mirror holder and the center part of the “U” extending in a rough approximation in parallel with the rotation axis. As a result, the longitudinal axis B is formed as a center axis of the pipe end in the pipe sleeve of the first or second connection component, transversely to the rotation axis. This allows on the one hand to revert to time-honored concepts, but on the other hand it is also possible to realize solutions for smaller numbers of pieces, for the tool costs for the individual components for each realization may be kept lower compared with a case in which the entire support structure consists of a “design” component to be specifically produced for the realization. The corresponding solution is shown by
The realization including a locking sleeve 12 and a support pipe 13 further improves the flexibility of use of this inventive holder. The random rotational position of the support pipe inside the pipe sleeve by rotation about the longitudinal axis B allows for different positions of the support pipe and thus of the mirror head relative to the rotation axis A in the utilization of the identical mirror holder. A same mirror holder may therefore be used for different vehicles.
With regard to the vibration properties it is crucial how rigid the mirror holder is made. Depending on the geometrical relations—distance of the holders 4, 6 from each other and of the mirror head from the rotation axis—as well as the rigidity of the further supporting structure—for example the support pipe 13 or the mirror head—it is important for the bolt 14 to possess a rigid position. Where sufficient freedom of design and structural space exist for the vehicle-side connection component 10, a second coupling of the bolt to the base body of the connection component 10 may also be established. This may be achieved by means of a transverse web 38 at the end of the bolt portion 14. Correspondingly, the sleeve 16 includes a through bore in this embodiment. An engagement element or holding member on the jacket surfaces 18 or 24 is furthermore not necessary any more for securing the position, because this function is already served by the transverse web 38.
Another embodiment of the invention is shown in
As the rotary connection of the invention fundamentally admits a rotation through 360° of the two connection components 10 and 12, on condition of overcoming the necessary fold-in force or locking/frictional forces, there is a possibility of providing in appropriate portions of the two connection components—with the exception of the jacket surfaces 18 and 24—one or more respective interacting catches 42 and 44 in order to limit the rotational range of the rotary connection. One example of such catches is shown in
In the preceding description the mirror holder of the invention has been described with reference to particular embodiments. The mirror holder defined in the claims is, however, not limited to these embodiments. In particular it is also possible to combine the features of the individual embodiments among each other.
If the mirror holder of the invention is made of two injection-molded plastic parts, these may be realized so as to directly represent the outer surfaces of the mirror holder that will be visible later on. This has the advantage that they may be recycled in a plastic-specific manner without any disassembling effort. On the other hand, however, it is conceivable to provide them with covers with the aim of achieving more freedoms with regard to the configuration of the components.
Furthermore, the mirror holder of the invention has been described with reference to various kinds of utility vehicle mirrors. The fundamental principle of the mirror holder may, however, be transferred to the field of cars and motorcycles.
Starting out from the solution as shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2009 013 645.2 | Mar 2009 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP10/53474 | 3/17/2010 | WO | 00 | 9/15/2011 |
