The invention starts with a windshield wiper with a wiper arm in accordance with the pre-characterizing clause of claim 1.
Known windshield wipers feature a wiper arm, which sits on a wiper shaft. This shaft is driven by a wiper motor. A wiper blade is connected in an articulated manner to the free end of the wiper arm. As a rule, the wiper blade has a multi-unit supporting bracket system with a central bracket. Linked to this are subordinate brackets, of which at least several, having claws on their ends, hold a wiper strip. Inarticulate wiper blades are also known, which, instead of the supporting bracket system, have a resilient elastic supporting element that is fabricated of plastic perpendicular to the windshield. In order to improve the spring property it can feature at least one spring rail made of spring steel. In an unloaded state, the supporting element has a greater curvature than the vehicle window so that the wiper strip is applied to the vehicle window with appropriate pressure distribution under the application force by the wiper arm.
Inarticulate wiper blades are low-slung, something that is very favorable with regard to its behavior in terms of flow technology and noise development in the air stream wind. A windshield wiper with an inarticulate wiper blade, which is linked to a wiper arm via a so-called xe2x80x9csidelock system,xe2x80x9d is known from DE 199 24 662 A1. For this purpose, a pin on the free end of the wiper arm, which features a U-shaped profile that is open towards the vehicle window, is riveted laterally, transverse to its longitudinal direction and pointing towards the wiper blade. The pin is pivoted in a rest bore hole of a connecting part, which is permanently connected to the supporting element of the wiper blade.
A bridge is arranged parallel to the pin on the wiper arm offset in the longitudinal direction and the bridge is bent at its free end towards the side of the pin. In an assembly position, in which the wiper blade is held transverse to the longitudinal direction of the wiper arm, the pin can be put into the rest bore hole of the connecting part. If the wiper blade is subsequently rotated in the longitudinal direction of the wiper arm, the bridge grips over the wiper blade and locks it with its bent end so that in an assembled state the wiper blade is guided onto the pin between the bent end of the bridge and the wiper arm. In the wiper blade""s operating position, the bridge dips into a corresponding groove of the connecting part and ends approximately flush with the upper side of the connecting part. For disassembly the wiper blade must be swiveled in the opposite direction until the bent end disengages and the wiper blade can be pulled from the pin.
Another sidelock system with a cylindrical adapter, which is used to compensate for different pin diameters, is known from U.S. Pat. No. 4,980,944 A1. The adapter has a rest bore hole, which is arranged eccentric to the outer contour of the adapter. In this arrangement, the eccentricity is selected in such a way that a continuous longitudinal slot is formed in the area of the circumference of the adapter. The adapter is pressed together for assembly and inserted into two openings of a U-shaped bracket of a wiper strip support. After being threaded in, the adapter reassumes its original form and with its circumference presses against the openings in the legs of the U-profile. A spring clip, which is arranged on the base surface of the U-profile and engages in the longitudinal slot, secures the adapter against twisting. Furthermore, it holds it in the axial direction by supporting itself on the lateral shoulders of the adapter. In a further assembly step, the pin fastened on the free end of the wiper arm can be put into the passage bore hole.
According to the invention, the wiper blade features a supporting bracket system with a center bracket that has an inset box, whose side walls are connected to one another via an articulated bolt and always feature at least one passage offset in the longitudinal direction to the articulated bolt. These types of wiper blades that are customary as such are used with wiper arms, which engage from above in the inset box with their hook-like end and encircle the articulated bolt with the use of an adapter or engage with two locking pins in two opposing passages.
According to the invention, a plastic adapter with a block-shaped center part is inserted from above into the inset box, which center part is adjacent with lateral guide surfaces to the insides of the side walls of the insert box. From a covering wall of the adapter, collars project laterally beyond the side walls, whereby the collars form guide surfaces in the area of the bridge to which a bearing surface of the wiper arm and the bent end of the bridge are adjacent in an assembled state. The collars form bearing eyes in the area of at least two opposing passages, which are arranged externally on the inset box and are separated from the center part by slots that run longitudinally. The slots are coordinated with the strength of the side walls. The center part features a rest bore hole matching the bearing eyes. In an assembled state the adapter is held on the articulated bolt via a clip in the center part by means of locking noses.
Using the adapter in accordance with the invention, a wiper arm, whose free end is provided with a transverse pin for a sidelock system, can also be used for a wiper blade with a supporting bracket system. With respect to wind noise and flow resistance, the advantages that are connected with the flat, low construction of the sidelock system can be achieved with simple means also in the case of wiper blades with a supporting bracket system. In doing so, the shape and dimensions of the wiper arm and the wiper blade are advantageously retained so that no structural modifications or new tools are required to fabricate the components. In addition, the parts of the wiper arm and the wiper blade, which are normally fabricated of metal, namely sheet steel, can be isolated from one another by the adapter made of plastic so that movement noise and wear are minimized. To do so, the bearing eyes, the rest bore hole and the pin are expediently coordinated in terms of their diameters and their positions to the passages and the clip in such a way that when the windshield wiper is in operation there is no contact between the pin and the wiper blade. In addition, as a rule plastic has good sliding properties for the placement of the pin.