DE19801058A1 - Motor vehicle windscreen wiper blade with curved spring rail - Google Patents

Abstract

The spring rail (12) is held loosely in a plastics sheath (14) in the closed space (34) and is fitted on the screen side with wiper blade (16) holders (40,42) and the space (34) wall (36) facing the screen is slit lengthwise in the center (28). The facing walls carry respectively holding strips (40) and claws (42) for engagement with the blade grooves (44). The lengthwise end walls of the sheath (14) space (34) are in part closed off and one wall can be flexibly deflected. The screen-facing wall of the plastics sheath is thicker than the opposing walls and the screen-facing sheath wall can form a second spring rail differing in curvature from the main rail (12).

Description

State of the art

For wiper blades in the preamble of claim 1 designated type is the spring rail over the entire from Wiper blade swept the wiping field as evenly as possible Distribution of the wiper blade starting from the wiper arm Ensure contact pressure on the disc. By a corresponding curvature of the unloaded spring rail - that is if the wiper blade does not touch the window the ends of the wiper blade operating completely on the Wiper strip created by the then tensioned Spring rail loaded to the disc, 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 slightly stronger than that in the wiping field greatest curvature measured on the window to be wiped. The wiper blade is therefore in the unloaded state Disc shape curved concavely. The spring rail replaced thus the elaborate support bracket construction with two in the Wiper strip arranged spring rails, as in conventional wiper blades is practiced (DE 15 05 357 A1).  

The invention is based on a wiper blade of the type of claim 1. In a known wiper blade of this type (DE-PS 12 47 161) is the wiper strip with that of the window facing band surface of the metallic spring rail glued. This adhesive connection is during the Wiping operation of a significant alternating stress exposed in conjunction with the inevitable Aging of the wiper strip and the adhesive to one Premature detachment of the wiper strip from the spring rail can lead. Furthermore, it is difficult to do the spring rail to design that on the one hand the connection to the Wiper strip requirements are met and for others an optimal distribution of the contact force is achieved. Requirements regarding the size, shape and choice of material stand here against each other.

Advantages of the invention

In the wiper blade according to the invention with the characteristic Features of claim 1 is such an adhesive connection not mandatory. The covering of the spring rail also ensures their holding means for a reliable, lasting Connection between spring rail and wiper strip. The slight play of at least one, loose in the wrapping accommodated spring rail causes a tension-free Holder of the wiper strip, which improves the wiping quality and also for a quick, quiet moving of the Wiper strip into their necessary drag position if that oscillating wiper blade out of its Reversal is moved. When wrapping the spring rail Completely surrounds the otherwise inevitable optical Surface treatment of the spring rail is eliminated because of a such when selecting and coordinating the using plastic at no additional cost can be taken into account. When producing the  Wrapping can also make demands on the design of the Wiper blade can be considered inexpensively. Furthermore can the at least one spring rail be free from the Connection requirements for optimal Tracking force distribution can be designed.

A particularly simple type of wrapping and with it connected holding means for the wiper strip is achieved if the casing wall of the casing facing the pane is opened via a central longitudinal slot and when along the two opposite each other Slot edges of the housing wall retaining strips are arranged, which with opposing claws in these assigned, in the two opposite each other Grip the longitudinal grooves arranged on the sides of the wiper strip.

In another embodiment of the envelope are on the the disk facing the housing wall of the casing in their longitudinal direction extending at a distance from each other and holding rails arranged parallel to each other arranged, which with mutually directed claws in assigned to them, in the opposite Grip the longitudinal grooves arranged on the sides of the wiper strip. This makes it possible to increase the thickness of the cladding walls minimize, thereby reducing the elasticity and the characteristic of the Spring rail is practically not affected.

This advantage can also be achieved in that the Holding strips or the holding rails through across them Longitudinal and spaced apart Slots are divided.

Especially when wrapping with a continuous, the Disk facing housing wall has it with regard to the elasticity of the spring rail proved to be advantageous,  if the wrapping is transverse to its longitudinal extent and spaced apart, close to the disc facing housing wall is divided slots.

Regarding the life of the wrapper it is expedient, the cross slots in the holding rails and the Cross slots in the envelope in the longitudinal direction of the Wiper blade to be staggered.

To secure the cover on the spring rail is the of the envelope enclosed space at its longitudinal ends End walls of the envelope at least partially covered by which - to simplify the exchange of Wiper strip - at least one end wall can be deflected elastically is.

So with problematic pane arrangements and with high ones Driving speeds a proper installation of the Wiper blade or the wiper strip on the window is ensured, is to the plastic casing Molded wind deflector.

According to a further development of the inventive concept, the Disc facing longitudinal wall of the casing thicker than that other longitudinal walls of the envelope. This can cause a Improvement of stability with particularly long Wiper blades can be reached.

If further with such a wiper blade that of the disc facing longitudinal wall of the casing as an additional spring rail is formed, in side view and individually considered one of the curvature of the metallic Spring rail has a different curvature, it is possible the metal spring rail over its entire longitudinal extent with a constant cross-section. The  Adjustment of the distribution of the contact force by Overall spring rail - metal spring rail and plastic Additional spring rail - to the through the disc course The specified requirements can only be met by the Design of the additional spring rail - width, thickness, Curvature course - can be achieved.

A particularly simple assembly of the wiper blade is reached when the wrapping in its middle section is cross-divided, because then the two wrapping parts of each one end of the metal spring rail pushed onto this can be.

It is useful if the two wrapping parts with Means for connecting are provided.

A further simplified construction of the wiper blade is possible if a device for Connect the wiper blade to a powered one Wiper arm is molded.

Further advantageous developments and refinements of Invention are in the following description of in the associated drawing illustrated embodiments specified.

drawing

The drawing shows:

Fig. 1 is a side view of a wiper blade according to the invention, Fig. 2 is a partial perspective view of an envelope belonging to the wiper blade according to Fig. 1, Fig. 3 is a section through the envelope in a view in the direction of arrow III in Fig. 2, with the wiper strip and mounted spring rail, Fig. 4 is a partial perspective view of a differently constructed envelope, Fig. 5 shows a section through the enclosure of FIG. 4 in a view in the direction of arrow V with marked wiper strip and mounted spring rail, Fig. 6 is a perspective end view of a wiper blade with a one-piece casing according to Fig. 2, Fig. 7 is a partially sectioned end view of the wiper blade with a differently constructed envelope, Fig. 8 is a plan view of a spring rail and an associated, radially split sheath in reduced scale, Fig. 9, the arrangement of FIG. 8 in side view, Fig. 10 and 11 schematic diagrams of A casing according to FIG. 3 arranged on this wind deflector strips, Fig. 12 is a partial perspective view of a transverse split shell having disposed on the enclosure parts connecting means, Fig. 13 a different kind of transverse partition a differently constructed envelope, Fig. 14a is a schematic representation of the curvature of a relaxed metal spring rail , Fig. 14b a possible curvature in an associated, formed as an additional spring rail plastic envelope, Fig. 14c, the resulting curvature after assembly of the spring rail according to Fig. 14a and the auxiliary spring rail according to Fig. 14b and Fig. 15 is a sectional view analogous to FIG. 3 by another embodiment.

Description of the embodiments

An elongated wiper blade 10 shown in FIG. 1 has a band-like elongated spring rail 12 ( FIG. 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 the embodiment, a connection device 18 is fastened either to the plastic casing 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 greatest curvature of the window surface, it can be clearly seen that the curvature of the unloaded wiper blade 10 , which has both ends against the window, is stronger than the maximum window curvature. Relative to the windshield surface 24 , the unloaded spring rail 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 this case, a voltage which builds up in the band-like, resilient spring rail 12 to a proper contact of the wiper strip 16 and the wiper lip 26 provides over its entire length on the vehicle window 24th

The special configuration of the wiper blade 10 according to the invention will now be discussed in more detail below. Fig. 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 . A claw-like retaining strip 40 is arranged on the mutually facing, mutually spaced, opposing slot edges 38 , the claws 42 of which are directed towards one another 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 spring rail 12 and 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 shown in FIG. 7 is fixedly connected to the enclosure 14, while the end wall is elastically deflectable 50 of FIG. 6 through corresponding cut-outs 52 in the upper enclosure wall 32 in the direction of the arrow 54. 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 covering 14 are dimensioned in such a way that the spring properties of the spring rail 12 are not impaired because the plastic used to produce the covering is elastic. In addition, a certain slight play 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 forming the wiper strip 16 with their claws 42 , which secure the wiper strip 16 free of tension on the casing 14 or on the spring rail 12 . This slight play between the holding strips 40 and the wiper strip 16 or between the claws 42 and the longitudinal grooves 44 also favors the turning behavior of the wiper lip 26 in the wiping direction reversal positions of the wiper blade 10 , into 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 a departure from the plastic sheathing 14 , the sheathing wall 136 facing the pane 24 is made continuous in the plastic sheathing 114 . This results in a more stable design of the casing 114 . Particularly in the case of very long wiper blades, however, it can then be advantageous if, in addition to the slots 158 also present here in the holding rails 140 formed on the covering wall 136 , the tubular covering 114 by lying transversely to its longitudinal extent and at a distance from one another to close to the disc 24 facing casing wall 136 reaching transverse slots is divided 160th 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 in the longitudinal direction between the slots 160 in the plastic casing 114 . Compared to the cross-sectional profile indicated in FIG. 4, however, this profile has been offset such that the cutting profile 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 also provided with claws 142 directed towards one another. These engage 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 . For further development of the plastic covering 114, reference is made to the explanations regarding the plastic covering 14 .

In FIGS. 8 and 9 an embodiment of the plastic encapsulation 214 is illustrated which is transversely divided in the longitudinal direction in its central portion. The two covering 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 comes to rest in the space 34 already described, which is also present in this embodiment. 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 sheathing 314 . The connection device 318 is located on the sheathing part 315 . A locking tooth 334 is formed on the upper covering wall 332 of the covering part 315 , which can cooperate with a catch receptacle 336 on the other covering part 313 if the two covering parts 313 , 315 are joined together 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 securing of the two casing members 413, 415 to each other is taken of the wiper arm 20 through the counter-connection means 19 which connect the two pin halves 421, surround 422, when the two parts 413, are joined together in the direction of arrow 416 415.

In Figs. 10 and 11 it is shown that also a wind-deflecting strip 570 can be molded onto the plastic sheath 514th It does not matter whether the deflector strip 570 according to FIG. 10 is molded onto the plastic covering 514 or is suspended according to FIG. 11. 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 possible without difficulty 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 covering 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.

Another essential 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. Fig. Shows that the plastic encapsulation 600 with respect to the disc positive (+) and negative 14b (-) has curvatures. 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 development of the invention is the fact 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 is shown in FIG. 14c. It is clear that FIGS. 14a, 14b and 14c are only intended to illustrate the principle of this training. 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 profiles described above.

All embodiments have in common, that the metallic spring rail 12 is arranged loosely in a housing-like, made of a plastic sheath 14 or 114 or 214 or 314 is substantially enclosed space 34, which at its side facing the disc 24 side with holding means 40, 42 or 140 , 142 is provided for the wiper strip 16 .

An embodiment of the invention similar to an attachment of the wiper strip to the spring rail can be achieved if a component is glued to the band surface of the spring rail 12 facing the washer 24 , which, based on the embodiment according to FIGS. 4 and 5, only has a support plate as there Wall 136 has, on which retaining rails 140 are integrally formed. Such a component made of a plastic is safer to glue to the metal spring rail than a rubber wiper strip, because - due to the multitude of material admixtures in the rubber - even the smallest mixture changes can lead to problems when gluing.

Difficulties of this kind arise when metal is glued and plastic not on.

Claims (13)

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 ) retaining 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. The wiper blade according to one of claims 1 to 6, characterized in that the space enclosed by the envelope (14) space (34) is covered at its longitudinal ends by end walls (48 and 50) of the envelope (14) at least partially, 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 sheath ( 314 or 414 ).