WO1999036300A1

WO1999036300A1 - Wiper blade for cleaning the glass panes of automobiles

Info

Publication number: WO1999036300A1
Application number: PCT/DE1998/002878
Authority: WO
Inventors: Thomas Schmidt; Thomas Kotlarski; Rudi Kisselmann
Original assignee: Robert Bosch Gmbh
Priority date: 1998-01-14
Filing date: 1998-09-29
Publication date: 1999-07-22
Also published as: JP2001516310A; KR20000076091A; ZA99211B; EP0966373A1; DE19801058A1

Abstract

Disclosed is a wiper blade (10) designed to clean the glass panes (24) of motor vehicles. The wiper blade has a band-shaped, longitudinal, metal spring bar (12) that is concavely curved in relation to the surface of the glass pane and a longitudinal rubber elastic wiper strip arranged between the band surface facing the glass pane (24) and the glass pane and parallel to the longitudinal axis of the spring bar. A particularly reliable connection between the metal spring bar (12) and the wiper strip (16) is achieved when the spring bar (12) is loosely mounted at least partially in a space (34) that is substantially surrounded by a housing-like plastic sleeve, which is fitted with fixing elements (40, 42) for the wiper strip (16) on the side (36) facing the glass pane.

Description

Wiper blade for cleaning windows of motor vehicles

State of the art

In the case of wiper blades of the type referred to in the preamble of claim 1, the spring rail should ensure as uniform a distribution as possible of the wiper blade contact pressure emanating from the wiper arm on the windshield over the entire wiper blade. By means of a corresponding curvature of the unloaded spring rail - i.e. if the wiper blade is not in contact with the windshield - the ends of the wiper strip which is fully attached to the windshield during operation of the wiper blade are loaded by the then tensioned spring rail to the windshield, even if the radii of curvature of spherically curved vehicle windows change at each wiper blade position. The curvature of the

The wiper blade must therefore be somewhat stronger than the greatest curvature measured on the windshield to be wiped in the wiping field. In the unloaded state, the wiper blade is therefore curved concavely to the course of the window. The spring rail thus replaces the complex support bracket construction with two spring rails arranged in the wiper strip, as is practiced with conventional wiper blades (DE 15 05 357 AI). The invention is based on a wiper blade according to the preamble of claim 1. In a known wiper blade of this type (DE-PS 12 47 161), the wiper strip is glued to the band surface of the metallic spring rail facing the disc. This adhesive connection is during the

Wiper operation exposed to considerable alternating stress, which in combination with the inevitable aging of the wiper strip and the adhesive can lead to premature detachment of the wiper strip from the spring rail. Furthermore, it is difficult to design the spring rail so that on the one hand the requirements placed on the connection to the wiper strip are met and on the other hand an optimal distribution of the contact force is achieved. Demands regarding the size, shape and choice of material conflict here.

Advantages of the invention

In the wiper blade according to the invention with the characterizing features of claim 1, such an adhesive connection is not required. The covering of the spring rail with its holding means ensures a reliable, permanent connection between the spring rail and the wiper strip. The slight play of the at least one spring rail, loosely accommodated in the casing, results in a tension-free one

Holder of the wiper strip, which improves the wiping quality and also ensures that the wiper strip is quickly and quietly moved into its required drag position when the wiper blade guided over the windshield is moved out of its reversed positions. If the sheath completely surrounds the spring rail, the otherwise unavoidable optical surface treatment of the spring rail can be dispensed with, because such a treatment can already be taken into account when selecting and coordinating the plastic to be used without additional costs. When producing the Wrapping requirements for the design of the wiper blade can also be taken into account at low cost. In addition, the at least one spring rail can be designed free of the requirements for the connection for an optimal distribution of the contact force.

A particularly simple type of sheathing and the holding means for the wiper strip connected to it is achieved if the housing wall of the sheathing facing the pane is opened via a central longitudinal slot and if holding strips are arranged along the two slot edges of the housing wall, which are spaced apart from one another and which engage with mutually directed claws in these associated longitudinal grooves arranged in the two opposite sides of the wiper strip.

In another embodiment of the casing, on the housing wall of the casing facing the pane, in the longitudinal direction, spaced apart and parallel to one another are arranged holding rails which engage with mutually directed claws in the associated longitudinal grooves arranged in the opposite sides of the wiper strip . This makes it possible to minimize the thickness of the cladding walls, which practically does not affect the elasticity and the characteristic of the spring rail.

This advantage can also be achieved in that the holding strips or the holding rails are divided by slots lying transversely to their longitudinal extent and at a distance from one another.

Particularly in the case of a casing with a continuous housing wall facing the pane, it has proven to be advantageous with regard to the elasticity of the spring rail. if the casing is divided by slots extending transversely to its longitudinal extent and at a distance from one another and extending close to the window of the housing wall.

With regard to the service life of the covering, it is expedient to arrange the transverse slots in the holding rails and the transverse slots in the covering offset with respect to one another in the longitudinal direction of the wiper blade.

To secure the casing on the spring rail, the space enclosed by the casing is at least partially covered at its longitudinal ends by end walls of the casing, of which - to simplify the replacement of the wiper strip - at least one end wall can be deflected elastically.

In order to ensure that the wiper blade or wiper strip is properly in contact with the pane in the case of problematic pane arrangements and at high driving speeds, a wind deflector strip is molded onto the plastic covering.

According to a development of the inventive concept, the longitudinal wall of the casing facing the pane is thicker than the other longitudinal walls of the casing. This can improve the stability of particularly long wiper blades.

If, in such a wiper blade, the longitudinal wall of the sheathing facing the window is designed as an additional spring rail, viewed in side view and when viewed individually, it has a curvature that deviates from the curvature of the metallic spring rail, it is possible for the metal spring rail to have a constant cross section over its entire longitudinal extent to train. The Adjustment of the contact force distribution through the overall spring rail - metal spring rail and plastic additional spring rail - to the requirements specified by the disk profile can be achieved solely by the design of the additional spring rail - width, thickness, curvature profile.

A particularly simple assembly of the wiper blade is achieved if the covering is cross-divided in its central section, because then the two covering parts can each be pushed onto the metal spring rail from one end thereof.

It is expedient if the two covering parts are provided with means for connecting them together.

A further simplified construction of the wiper blade is possible if a device for connecting the wiper blade to a driven wiper arm is molded onto the plastic covering.

Further advantageous developments and refinements of the invention are specified in the following description of exemplary embodiments shown in the associated drawing.

drawing

FIG. 1 shows a side view of an embodiment of the invention

Wiper blade, Figure 2 is a partial perspective view of a cover belonging to the wiper blade according to Figure 1, Figure 3 is a section through the cover in a view in the direction of arrow III in Figure 2, with the wiper strip and mounted spring rail, Figure 4 a partial perspective view of a differently designed casing, FIG. 5 shows a section through the casing according to FIG. 4 in a view in the direction of arrow V with the wiper strip and mounted spring rail, FIG. 6 shows a perspective end view of a wiper blade with a one-piece casing according to FIG. 2, FIG partially sectioned end view of the wiper blade with a differently designed casing, FIG. 8 is a plan view of a spring rail and an associated, cross-divided casing in a reduced view, FIG. 9 shows the

Arrangement according to FIG. 8 in side view, FIGS. 10 and 11 basic representations of the covering according to FIG. 3 with wind deflector strips arranged thereon, FIG. 12 a perspective partial representation of a cross-divided covering with arranged on the covering parts

Connection means, FIG. 13 another type of transverse division of a differently designed casing, FIG. 14a a basic illustration of the curvature of a relaxed metal spring rail, FIG. 14b a possible course of curvature with an associated, as

14c and the additional spring rail according to FIG. 14b and FIG. 15 a section analogous to FIG. 3 through a further exemplary embodiment. FIG. 14c shows the course of curvature after the assembly of the spring rail according to FIG. 14a and the additional spring rail according to FIG.

Description of the embodiments

An elongated wiper blade 10 shown in FIG. 1 has a band-like elongated spring rail 12

(Figure 3), which is surrounded by a plastic sheath 14. The plastic covering 14 holds an elongated rubber-elastic wiper strip 16 on the metal spring rail 12 so that the spring rail 12 and the wiper strip 16 lie parallel to one another along the longitudinal axes. Depending on In one embodiment, a connection device 18 is fastened either to the plastic covering 14 or to the metal spring rail 12, with the aid of which the wiper blade 10 can be connected to a wiper arm 20 guided on the motor vehicle body. The wiper arm 20 and thus also the wiper blade 10 are loaded in the direction of the arrow 22 toward the pane 24 of the motor vehicle indicated by a dash-dotted line in FIG. 1. Since the dash-dotted line 24 is intended to represent the strongest curvature of the window surface, it can be clearly seen that the curvature of the unloaded wiper blade 10 resting on the window with its two ends is stronger than the maximum window curvature. Relative to the window surface 24, the unloaded spring mechanism 12 or the wiper blade 10 is therefore concavely curved. Under the

Contact pressure (arrow 22), the wiper blade with a wiper lip 26 of the wiper strip 16 (FIG. 3) lies against the window 24 over its entire length. In the process, a tension builds up in the band-like, spring-elastic spring rail 12, which ensures that the wiper strip 16 or the wiper lip 26 bears against the motor vehicle window 24 over its entire length.

The special configuration of the wiper blade 10 according to the invention will now be discussed in more detail below. Figure 3 shows the metal spring rail 12, which practically forms the backbone of the wiper blade 10. It is surrounded by the plastic covering 14. The casing 14 has a central longitudinal slot 28, via which a space 34 enclosed by the casing walls 32, 36 is opened. The central longitudinal slot 28 is arranged on the cladding wall 36 which, when the wiper blade 10 is ready for operation, faces the window 24 of the motor vehicle to be wiped. The metal spring rail 12 is housed loosely in the space 34. On the facing each other, at a distance from each other running, opposing slot edges 38, a claw-like retaining strip 40 is arranged, the claws 42 are directed towards each other at a distance from the space 34.

They engage in them associated longitudinal grooves 44 arranged in the opposite sides of the wiper strip 16, so that there is a reliable securing for the wiper strip 16 on the spring rail 12. Securing in the longitudinal direction between the spring rail 12 and the casing 14 is achieved in that - as can be seen from FIGS. 6 and 7 - the space 34 enclosed by the casing 14 is at least partially covered at its longitudinal ends 46 by end walls 48 and 50, respectively. The end wall 48 according to FIG. 7 is fixedly connected to the casing 14, while the end wall 50 according to FIG. 6 can be elastically deflected in the direction of the arrow 54 by corresponding cutouts 52 in the upper casing wall 32. This makes it possible to temporarily open the space 34 on the end face, so that the casing 14 and / or the wiper strip 16 can be separated from the spring rail 12, for example for the exchange of these components.

The walls 32 and 36 of the plastic sheath 14 are dimensioned so that an impairment of the

Spring properties of the spring rail 12 do not take place because the plastic used to produce the casing is elastic. In addition, a certain slight clearance is present between the spring rail 12 and the covering walls 32, 36, which allows a relative movement between the covering 14 and the spring rail 12. The same applies to the arrangement of the holding means for the holding strips 40, which form the wiper strip 16, with their claws 42, which secure the wiping strip 16 free of tension on the casing 14 or on the spring rail 12. This little game between the Holding strips 40 and the wiper strip 16 or between the claws 42 and the longitudinal grooves 44 also favors the folding behavior of the wiper lip 26 in the

Wiping direction reversal positions of the wiper blade 10, in the so-called drag position required for clean and noiseless wiping. In the case of particularly strongly curved pane surfaces, it can prove to be helpful if the holding strips 40 of the plastic covering 14 are divided by slots 58 lying at a distance 56 from one another transversely to their longitudinal extension, the depth of which extends close to the covering wall 36 (FIGS. 2 and 3).

Another embodiment of the plastic covering 114, shown in detail in FIGS. 4 and 5, corresponds essentially to the plastic covering 14 already described. In contrast to the plastic covering 14, the covering wall 136 facing the pane 24 is designed to be continuous. This results in a more stable design of the covering 114. However, it can then be particularly widespread with very long wiper blades

It would be advantageous if, in addition to the slots 158 also present in the holding rails 140 formed on the envelope wall 136, the hose-like envelope 114 by transverse slots 160 extending transversely to its longitudinal extent and at a distance from one another and reaching as close as possible to the envelope wall 136 facing the disk 24 is divided. In this case, it is advantageous to arrange the transverse slots 158 in the holding rails 140 and the transverse slots 160 in the casing 114 offset in the longitudinal direction of the wiper blade 10. This can be seen from FIG. 4, where the distance between the transverse slots in the casing 114 is provided with the reference number 162. The slots 158 in the holding rails 140 lie, seen in the longitudinal direction, between the slots 160 in the plastic sheath 114. Compared to the cross-sectional profile indicated in FIG. 4, this is However, the course has been offset in such a way that the cutting course leads through both the slots 160 and the slots 158. As in the embodiment according to FIGS. 2 and 3, the holding rails 140 are likewise provided with claws 142 directed towards one another. These take effect as

Holding means in the longitudinal grooves 44 of the wiper strip 16 already described. Otherwise, the plastic covering 114 corresponds completely to the plastic covering 14 according to FIGS. 2 and 3, which has already been described in detail

Plastic covering 114 referred to the explanations for the plastic covering 14.

FIGS. 8 and 9 show an embodiment of the plastic covering 214 which is divided transversely in its central section in the longitudinal direction. The two sheathing parts 213 and 215 are then pushed onto the metallic spring rail 12 in the direction of the arrows 218 in such a way that the metallic spring rail 12 into the space 34 already described, which also applies to this

Embodiment is present, comes to rest. After the covering parts 213, 215 have been completely pushed onto the spring rail 12, the two separating edges 220 of the covering parts 213, 215 which then lie against one another can be connected to one another by gluing, welding or the like. It is clear that corresponding recesses must be provided in the upper cladding wall of this embodiment, which also allows the cladding parts 213, 215 to be pushed open when the connecting device 18 is fastened to the spring rail 12.

It can be seen from FIG. 12 that the connecting device 318 can also be molded onto the cross-divided, two-part plastic covering 314. Here is the Connection device 318 on the wrapping part 315. A locking tooth 334 is formed on the upper wrapping wall 332 of the wrapping part 315, which can cooperate with a locking receptacle 336 on the other wrapping part 313 when the two wrapping parts 313, 315 are joined in the direction of arrow 316. Since the latching receptacle 336 is arranged in a tab 340 of the wrapping part 313 that can be deflected elastically in the direction of the arrow 338, a simple and reliable connection of the two wrapping parts 313, 315 is achieved with one another.

Another type of transverse division of the sheathing 414 is shown in FIG. 13. There, the parting plane runs through the longitudinal axis of a connecting bolt 420 (FIG. 1) which serves to connect the wiper blade 10 to the wiper arm 20 and which belongs to the integrally formed connecting device 418. The two sheathing parts 413, 415 are secured to one another by the counter-connection means 19 of the wiper arm 20, which grip around the two pin halves 421, 422 when the two parts 413, 415 are joined together in the direction of the arrow 416.

FIGS. 10 and 11 show that a wind deflector bar 570 can also be molded onto the plastic covering 514. It does not matter whether the

Deflection strip 570 is formed on the plastic sheathing 514 in accordance with FIG. 10 or is formed in a hanging manner in accordance with FIG. Even if the cross-sectional shape of the casing according to FIGS. 2 and 3 has been chosen for the explanation of this important detail, it is also readily possible to attach the wind deflector strip 570 to a plastic casing 114 according to FIGS. 4 and 5. In this case it is of course clear that the wind deflector strip 570 must also be provided with the slots 160 of the plastic sheath shown there so that the elasticity of the Plastic covering and thus the elasticity of the spring rail 12 located in the space 34 is not impaired.

A further, essential further development of the invention is explained below with reference to FIGS. 14a, 14b and 14c. In this embodiment, a plastic sheath 600 is advantageously used, as has been illustrated and explained with reference to FIGS. 4 and 5. In addition, this one-piece plastic sheath 600 is designed as an additional spring rail. The wrapping wall designated 136 in FIGS. 4 and 5 is thickened or otherwise reinforced in such a way that its rigidity is greater than the other wrapping walls. Figure 14b shows that the plastic wrap 600 has positive (+) and negative (-) curvatures with respect to the disc. The metallic spring rail 602 (FIG. 14a) is only positively (+) curved. If the positively curved, metallic spring rail 602 is now inserted into the plastic sheath 600 preformed according to FIG. 14b, the suspension properties of the spring rail 602 can be changed in the desired manner. A major advantage of this further development of the invention is that the metallic spring rail 602 can have a constant cross section over its entire longitudinal extent. The adjustment of the spring rail 602 to the respective requirements determined by the shape of the windshield can be achieved by appropriate shaping and design of the additional spring rail 600. After the metallic spring rail 602 and the sheath 600 - which is designed as an additional spring rail and have a curvature that deviates from the curvature of the metallic spring rail - are joined together, a shape of the overall spring rail 604 can result, as shown in FIG. 14c. It is clear that Figures 14a, 14b and 14c are only the principle of this training should clarify. The idea of the invention can in no way be limited to the shapes shown in these figures.

In an embodiment shown in FIG. 15, the sheath 700 has two lateral longitudinal channels 702, in which two spring rails 704 are loosely inserted. The spring rails 704 are held in the channels 702 by holding elements (not shown) molded onto the casing or by claws and end clips applied from the outside. This version is particularly suitable for realizing the combination of the different curvature curves described above.

All of the exemplary embodiments have in common that the metallic spring rail 12 is arranged loosely in a housing-like casing 14 or 114 or 214 or 314 which is essentially enclosed and is made of a plastic and which is provided on its side facing the disk 24 with holding means 40, 42 or 140, 142 is provided for the wiper strip 16.

An embodiment of the fastening of the wiper strip on the spring rail, which embodiment is similar to the invention, can be achieved if the wiper 24 faces on

A component is glued onto the band surface of the spring rail 12, which, based on the embodiment according to FIGS. 4 and 5, has only one support plate, such as the wall 136 there, to which the holding rails are molded in accordance with 140. Such a component made of a plastic is more securely to be glued to the metal spring rail than a rubber wiper strip, because - due to the large number of material admixtures in the rubber - even the smallest mixture changes can lead to problems when gluing. Such difficulties do not occur when metal and plastic are glued.

Claims

Expectations

1. wiper blade (10) for cleaning windows (24) of motor vehicles with at least one band-like, elongated, metallic, to the window surface (24) concavely curved spring rail (12) and an elongated, rubber-elastic wiper strip (16) between the window and a The band surface of the at least one spring rail facing the disc is arranged parallel to the longitudinal axis, characterized in that the at least one spring rail (12) is at least partially loosely enclosed in a casing (14 or 114 or 214 or 314 or 314 or 414 or 514 or 614) is essentially enclosed space (34), which is provided on its side facing the window (24) with holding means (40, 42 or 140, 142) for the wiper strip (16).

2. Wiper blade according to claim 1, characterized in that the disc (24) facing the housing wall (36) of the casing (34) is opened via a central longitudinal slot (28) and that along the two mutually opposite slot edges of the housing wall ( 36)

Holding strips (40) are arranged, which engage with mutually directed claws (42) in the associated longitudinal grooves (44) arranged in the opposite sides of the wiper strip (16).

3. Wiper blade according to claim 1, characterized in that on the disc (24) facing wall (36) of the sheath (134) extending in the longitudinal direction, spaced apart and parallel to each other holding rails (140) are arranged, which with mutually directed claws engage in (142) associated longitudinal grooves (44) arranged in the opposite sides of the wiper strip (16).

4. Wiper blade according to one of claims 2 or 3, characterized in that the holding strips (40) or the holding rails (140) are divided by transverse to their longitudinal extension and spaced slots (58 and 158).

5. Wiper blade according to one of claims 3 or 4, characterized in that the covering (144) on its side facing away from the window (24) by transversely to its longitudinal extent and at a distance from one another, up to close to the wall facing the window (136 ) extending slots (160) is divided.

6. Wiper blade according to one of claims 4 or 5, characterized in that the transverse slots (158) in the holding rails (140) and the transverse slots (160) in the casing (114) in the longitudinal direction of the wiper blade (10) are arranged offset to one another.

7. Wiper blade according to one of claims 1 to 6, characterized in that the space (34) enclosed by the covering (14) is at least partially covered at its longitudinal ends by end walls (48 or 50) of the covering (14), of which at least one end wall (50) can be deflected elastically.

8. Wiper blade according to one of claims 1 to 7, characterized in that a wind deflector strip (570) is integrally formed on the plastic covering (514).

9. Wiper strip according to claim 1 and one of claims 3 to 8, characterized in that the longitudinally extending casing wall (136) facing the disc (24) is thicker than the other longitudinal walls of the casing (114).

10. Wiper blade according to claim 9, characterized in that the disk (24) facing the envelope wall (136) is designed as an additional spring rail and viewed in side view has a curvature deviating from the curvature of the metallic spring rail (12).

11. Wiper blade according to one of claims 1 to 10, characterized in that the covering (214) is cross-divided in its central section.

12. Wiper blade according to claim 11, characterized in that the two covering parts (314, 315) are provided with means (334, 336, 340) for connecting them together.

13. Wiper blade according to one of claims 1 to 12, characterized in that a device (318 or 418) for connecting the wiper blade (10) to a driven wiper arm (20) is integrally formed on the plastic covering (314 or 414).