Prior art The invention relates to a wiper arm head for a windshield wiper system of a motor vehicle, according to the preamble of Claim 1. The invention furthermore relates to a fastening device for a wiper arm head according to the invention.

A wiper arm head for a windshield wiper system of a motor vehicle, having the features of the preamble of Claim 1, is known from DE 10 2008 034 373 Al . A wiper arm head of this type serves for pivotally fastening a wiper arm bar of the wiper arm, on the one hand, and for fastening the wiper arm to a pivotally arranged driveshaft for driving the wiper arm, on the other hand. The wiper arm head herein is connected in a rotationally fixed manner to the shaft by way of a form-fitting or force-fitting connection, respectively.

In order for the end side of the fastening region of the wiper arm head on the drive shaft that faces the wiper arm head to be protected or covered, respectively, the known wiper arm head has a pivotally arranged cover cap, which by way of a latch connection is connected to the wiper arm head per se. This requires that latch elements are provided in each case on the wiper arm head as well as on the cover cap, so as to configure the latch connection. Latch elements of this type require an additional installation space on the wiper arm head, said additional installation space enlarging the wiper arm head in terms of the width, for example. Furthermore, latch elements of this type that are arranged or configured, respectively, outside the cover cap on the wiper arm head cause an additional complexity in manufacturing. Disclosure of the invention

Proceeding from the prior art illustrated above, the invention is based on the object of refining a wiper arm head for a windshield wiper system of a motor vehicle, according to the preamble of Claim 1, in such a manner that no additional latch elements have to be configured on the wiper arm head except for on the cover cap in order for a latch connection to be configured in the installed state of the wiper arm head on the drive shaft of the motor vehicle.

This object is achieved according to the invention and according to Claim 1 in that the latch element of the latch connection which is arranged at the cover cap is configured to interact with a matching latch element at the (drive) shaft. A configuration of the wiper arm head of this type thus has the effect that the wiper arm head outside the cover cap can be configured in a particularly simple and compact manner since said wiper arm head per se does not require any latch element that interacts with the latch element on the cover cap.

Advantageous refinements of the wiper arm head according to the invention for a windshield wiper system of a motor vehicle are set forth in the dependent claims. All combinations of at least two features that are disclosed in the claims, the description, and/or the figures, are within the scope of the invention.

A constructive arrangement or design, respectively, of the latch element on the cover cap, in which the former is formed integrally, that is to say in a monolithic VAL-P-02857-DE1 - 3 - manner, with the cover cap and, when installed, is arranged to be aligned with a longitudinal axis of the shaft receptacle of the wiper arm head on the shaft is particularly preferable. On account thereof, the latch element on the cover cap can already be taken into account in the production of the cover cap, that is to say such that no additional assembly procedure for a (separate) latch element is required. In a refinement of the last-mentioned proposal that in terms of construction is preferable, it is provided that the latch element comprises a peripheral wall, which protrudes from the internal side of a cover wall of the cover cap.

In order to enable an arrangement of the cover cap on the wiper arm head that is secured against tilting, or is optimized in terms of kinematics, it is moreover preferably provided that the (pivotable) bearing of the cover cap is effected at two bearing points arranged laterally on the wiper arm head or the cover cap, respectively .

A cover cap of this type can be produced in a particularly simple and cost-effective manner when said cover cap is formed as a plastic injection moulded part .

The invention also comprises a fastening device for a wiper arm head according to the invention, as has been described to this point, of a windshield wiper system, wherein the fastening device comprises a (drive) shaft which can be rotationally fixed to the wiper arm head. The fastening device according to the invention is distinguished in that the shaft on that side that faces the cover cap comprises a further latch element for forming the latch connection with the cover cap on the internal side of the cover cap. VAL-P-02857-DE1 - 4 -

It is particularly preferable for the further latch element to be arranged at the shaft end. It can be provided herein that the further latch element is formed in a monolithic manner with the shaft, or the shaft end, respectively, for example by way of a forging procedure or a similar production step. It is to be taken into account herein in the configuration of the shaft end that interacts with the wiper arm head that the shaft end usually has a conically shaped portion, for example, which serves for fastening in a reciprocal receptacle of the wiper arm head. Conical portions of this type can be generated, for example, by forging or similar production procedures such that it is conceivable for the further latch element that is arranged on the shaft end to be simultaneously configured by a corresponding shaping of the tool such that the further latch element for the manufacture thereof does not require any additional or separate production step, respectively.

In order for a particularly reliable or mechanically advantageous latch connection, respectively, to be configured it is provided that the further latch element at the shaft end is formed in the shape of a spherical segment. Configuration of this type is therefore advantageous above all also because the position in terms of the rotation angle of the shaft in relation to the cover cap is irrelevant on account thereof.

In order for the wiper arm head to be fastened in a rotationally fixed manner to the shaft, threaded nuts which are fastenable to a corresponding threaded portion of the shaft are usually used. In order for the threaded nut to be able to be readily assembled despite the further latch element being arranged on the shaft end, it is moreover provided according to the invention that a threaded portion follows the further latch element on the side of the shaft facing away from the cover cap, wherein the further latch element in a plane running perpendicularly to the longitudinal axis of the shaft has a smaller cross-sectional area than the cross-section area of the threaded portion. On account thereof, the threaded nut by way of the internal thread thereof can be pushed axially over the region of the further latch element such that the threaded nut can interact with the threaded portion.

Further advantages, features, and details of the invention are derived from the following description of preferred exemplary embodiments and by means of the drawing in which:

Fig. 1 in an exploded illustration shows the relevant components of a fastening device for a wiper arm head on a shaft;

Fig. 2 shows the fastening device according to Fig. 1 in the assembled state in a partially sectional illustration in order for the latch mechanism between the cover cap and the shaft to be explained;

Fig. 3 shows a part-region of Fig. 2 in an enlarged illustration in the longitudinal section; and

Fig. 4 shows an illustration corresponding to that of Fig. 3 in a state in which the cover cap is connected to the shaft end while configuring a latch connection.

The same elements, or elements with the same function, respectively, are provided with the same reference signs in the figures.

A fastening device 100 for a wiper arm head 10 of a windshield wiper system of a motor vehicle is illustrated in Fig. 1. The fastening device 100 comprises a wiper shaft or shaft 1, respectively, which is arranged so as to be at least indirectly pivotable by a drive unit (not shown) about a longitudinal axis 2. The wiper arm head 10 is fastened in a rotationally fixed manner to the shaft 1.

The wiper arm head 10 has a main part 11 which is composed in particular from steel sheet or cast metal and which is connected to a cover cap 12. The main part

11 is configured so as to be approximately bar-shaped and on that side that faces the shaft 1 has a through bore as a shaft receptacle 14 for the shaft 1. The longitudinal axis of the shaft receptacle 14 is aligned to the longitudinal axis 2 of the shaft 1. As can be seen in particular by means of Figs. 3 and 4, the shaft receptacle 14 comprises a conically configured portion 15 which interacts with a reciprocal portion 3 on the shaft 1. A clearance 16 which in terms of the cross section is enlarged and serves for receiving a fastening nut 5 is moreover configured on the upper side of the main part 11. The fastening nut 5 in the region of a threaded portion 6 of the shaft 1 is connectable to the shaft 1 and serves for fastening the wiper arm head 10 to the shaft 1.

Two bearing points 21, 22 for fastening the cover cap

12 so as to be pivotable about a pivot axis 23 are configured at a spacing from the shaft receptacle 14 on the main part 11 on opposite sidewalls 17, 18 of the main part 11, that is to say so as to be spaced apart from a symmetry plane of the main part 11, said bearing points 21, 22 being configured so as to be cylindrical in the cross-section, wherein the pivot axis 23 runs perpendicularly to the longitudinal axis 2 of the shaft The main part 11 on the upper side thereof and in the region of the two side walls 17, 18 is covered by the cover cap 12. To this end, the cover cap 12 has a substantially U-shaped cross-section having two side wall portions 24, 25 and a cover wall 26 that covers the upper side of the main part 11. The two side wall portions 24, 25 in the region of the bearing points 21, 22 of the main part 11 have counter portions 27 that are configured in the shape of a divided circle such that a (first) latch connection for mounting the cover cap 12 so as to be pivotable on the main part 11 can be configured between the cover cap 12 and the main part 11 by joining the cover cap 12 in the region of the counter portions 27 with the bearing points 21, 22.

As can be seen in particular by means of the illustration of Figs. 2 to 4, the cover cap 12 in the region of the cover wall 26 on that side that faces the shaft 1 has a latch element 28 which is formed in a monolithic manner with the internal side of the cover wall 26. The latch element 28 comprises a preferably radially encircling wall 29 having at least one, preferably two, longitudinal slots 20 that are disposed so as to be mutually offset by 180 degrees, and an internal contour 31 that is configured in the shape of a spherical segment. The latch element 28 serves for configuring a latch connection 30 to the shaft 1. To this end, the shaft 1 at the shaft end 7 as a reciprocal further latch element 9 has a portion 32 that is configured so as to be reciprocal to the internal contour 31 of the latch element 28, that is to say is configured in the shape of a spherical segment. It can be furthermore seen in particular by means of Fig. 4 that the cross-sectional area f of the further latch element 9 in a plane that runs perpendicularly to the longitudinal axis 2 of the shaft 1 is smaller than the cross-section area F of the threaded portion 6 which directly adjoins the further latch element 8 on the shaft 1, wherein the fastening nut 5 in the case of a wiper arm head 10 being fastened to the shaft 1 is disposed below the further latch element 8, or the region of the further latch element 8 is freely accessible to the latch element 28. It can be furthermore seen by means of Fig. 4 that the wall 29 in the case of a latch connection 30 being configured is disposed so as to be concentric with the longitudinal axis 2 of the shaft 1.

In order for the wiper arm head 10 to be assembled on the shaft 1, the former in a first operating step is fastened in a rotationally fixed manner to the shaft 1 by means of the fastening nut 5. The cover cap 12 herein is pivoted about the bearing points 21, 22 in such a manner that an accessibility, or assembly, respectively, of the fastening nut 5 on the shaft 1 is enabled. The cover cap 12 is subsequently pivoted about the bearing points 21, 22 of the main part 11 such that the wall 29, or the latch element 28, respectively, is brought to be operatively connected to the further latch element 9 on the shaft 1. By applying a latching force R in the direction of the longitudinal axis 2 of the shaft 1 on the cover cap 12 the wall 29 herein engages over the further latch element 8 and forms the latch connection 30.

The fastening device 100, or the wiper arm head 10, respectively, described to this extent can be varied or modified, respectively, in many ways without departing from the concept of the invention. of reference signs Shaft

Longitudinal axis Portion

Fastening nut

Threaded portion Shaft end

Latch element

Wiper arm head

Main part

Cover cap

Shaft receptacle

Portion

Clearance

Side wall

Side wall

Longitudinal slot

Bearing point

Bearing point

Pivot axis

Side wall portion

Side wall portion

Cover wall

Counter portion

Latch element

Encircling wall

Latch connection

Internal contour

Portion

Fastening device f Cross-sectional area F Cross-section area R Latching force