Title of Invention

FASTENING PART OF A WIPER AND METHOD FOR PRODUCING THE SAME

Abstract

The invention is based on a fastening part (10) of a wiper, which has a receiving opening (12, 46) at one end for a wiper shaft (44) and forms part (14) ofa hinged joint at the other end and is formed from a flat plate (28) by deep-drawing, punching and bending, has a u-shaped cross-sectional profile (20) and a spring attachment(16). It is proposed that the spring attachment (16) is formed from a side wall (24) of the u- shaped cross- sectional profile (20) by deep-drawing.

Full Text

The invention is based on a fastening part of a wiper and method for producing the same. Known wipers have a wiper arm which comprises a driven fastening part and a joint part which is connected to the latter via a hinged joint and has a wiper rod. A wiper blade is coupled to the free end of the wiper rod. During the pivoting movement of the wiper, the wiper blade is guided over the vehicle window, a tension spring pre-tensioning the hinged joint, so that the wiper blade is pulled towards the vehicle window. The tension spring is accommodated in the u-shaped cross-sectional profile of the joint part and is attached by one end to a transverse pin on the joint part. The tension spring is fastened by its other end via a c-shaped clip to a spring attachment on the fastening part. In the case of known fastening parts, this spring attachment is either integrally formed or is formed by a rivet pin. Thus, for example, fastening parts which are designed as sheet-metal bent parts have, in one variant, a pin as the spring attachment. During manufacturing this pin is pressed into holes in the side walls of the U-shaped cross-sectional profile of the fastening part and is subsequently riveted. In the process, in contrast to a single-piece fastening part, additional manufacturing times for the installation and for the production of the additional components occur. The tension spring exerts relatively large forces on the spring attachment. In addition, these forces have different directions in the working position and in the folded position, for example differing by 90°, with the result that a relative movement occurs between the tension spring or the c-shaped clip and its attachment. In order to obtain a sufficiently great strength, the attachment pin on the fastening part generally consists of a different material than the sheet-metal bent part. However, when different materials are connected there is the risk of contact corrosion in the connecting region. In addition to a part of the hinged joint and a spring attachment, the fastening part also has at the opposite end a fastening region via which the wiper arm is connected fixedly, but detachably, to a wiper shaft. The fastening region is designed as a shaft-hub connection and is formed by a receiving opening having an inner cone into which the free end of the wiper shaft, which end has a corresponding outer cone, protrudes. The two parts are clamped together by a screw nut. Variants are also known, in which the conical connecting region is situated between an attachment of the screw nut and the receiving opening of the fastening part. The shape of the receiving opening is produced in different ways. If the fastening part consists of a dieca sting or of plastic, the receiving opening is, as a rule, shaped at the same time during the casting or injection moulding, while in the case of sheet-metal bent parts, it is produced in a plurality of drawing steps. Advantages of the invention According to the invention, the spring attachment of a fastening part designed as a sheet-metal bent part is formed from a side wall of the u-shaped cross-sectional profile by deep drawing. The sheet-metal bent part is therefore designed as a single piece and has all of the important functional elements, such as a receiving opening for a wiper shaft, a part of the hinged joint and a spring attachment for a tension spring. As many functions as possible are integrated in one component in order to avoid subsequent installation steps. This reduces the manufacturing times and the costs. In addition, contact corrosion is eliminated on a single-piece fastening part, since there are no critical connecting points, for example to rivet pins. In order to better support the spring forces and introduce them into the side wall of the U-profile, the deep-drawn spring attachment has a conical shape which widens towards the side wall. As a result, the spring attachment is of stable design, with the result that it is hardly deformed elastically when subjected to a force and that the bearing force for the wiper blade is thereby affected*by a small tolerance, if at all. The spring attachment has a round cross-sectional shape. It may also be oval, in which case in the working position of the wiper arm the larger diameter should expediently face in the direction of force of the tension spring. The spring attachment decreases in cross-section from the side wall as far as a constriction and increases again from the latter to the free end. In addition, the contour of the constriction is matched to the cross-sectional contour of a C-shaped retaining clip, with the result that the tension spring is securely attached and does not slide off from the attachment due to vibrations. A lateral stop is required to fix the tension spring in place. The said stop is formed in a simple manner by compression of the free end of the spring attachment or, in a variant of the invention, by perforating and subsequently widening the end region. In order to reduce the friction between the spring attachment and the c-shaped clip, and therefore the wear due to the C-clip slightly rotating during operation, in the region of the constriction the spring attachment expediently has a coating of bearing material, for example plastic, or an additional plastic ring. This enables the wiper arm to be swung down more easily from the vehicle window. The spring attachment is preferably deep-drawn only from one side wall of the U-profile and protrudes into the central region of the U-shaped cross-sectional profile. In addition to the spring attachment, this provides a clearance in which, for example, the hose for supplying water to a window washer system can be accommodated. A tapering on the fastening part, which tapering can be seen laterally because of the deep-drawn spring attachment, lies at a point which is covered either by the joint part or, if appropriate, by a covering cap. In this connection, it is advantageous for the spring attachment to originate from a side wall of the fastening part, which side wall faces downwards, for example towards a vehicle bonnet, in order to avoid the accumulation of dirt and water in the outwardly open cavity of the spring attachment. According to the invention, the spring attachment is produced in a number of drawing steps. First of all, material is drawn in a very large area in order to obtain wall thicknesses of the same size in all regions. Subsequently, in a number of steps the conical region and, at the closed end, a cylindrical region are formed and the end piece which is designed as a stop is formed. Since the receiving opening for the wiper shaft is, like the spring attachment, deep-drawn, both regions can be produced by one die, particularly since approximately the same number of drawing steps (about 5-7) is required for the production of both regions. Although the deep-drawing die is slightly more costly as a result, the processing times in the die are not increased. The production of the two severely deformed regions of the fastening part with comparatively little additional outlay for the production of the die therefore gives rise to a cost-effective component. The receiving opening and the spring attachment are expediently placed in one phase into the still flat sheet-metal strip. The U-profile which is characteristic for the fastening part is subsequently formed by angling the side walls. After this deforming process, the spring attachment is situated on one side wall and the receiving opening for the shaft-hub connection is situated in the covering wall. If required, the positional accuracy of the spring attachment can be ensured in a simple manner after the bending by an additional calibrating step. Accordingly the present invention provides a fastening part of a wiper, which has a receiving opening at one end for a wiper shaft and forms part of a hinged joint at the other end and is formed from a flat plate by deep-drawing, punching and bending, has a U-shaped cross-sectional profile and a spring attachment, characterized in that the spring attachment is formed from a side wall of the u-shaped cross- sectional profile by deep-drawing. Accordingly the present invention also provides a method for producing a fastening part as described herein, characterized in that first of all the spring attachment is formed in the flat plate and subsequently the parts of the side walls are angled relative to the part of the covering wall. Drawing Further advantages emerge from the following description of the drawing. Exemplary embodiments of the invention are illustrated in the drawing. The drawing, the description and the claims contain numerous features in combination. The expert will expediently also consider the features individually and put them together to form sensible further combinations. In the drawing: Fig.l shows a perspective illustration of a fastening part from above, Fig.2 shows one end of the fastening part together with a spring attachment on anenlarged scale from a different perspective, Figs 3-5 show a partial section of a flat sheet metal part in the region of the spring attachment at different manufacturing stages, Figs 6-7 show variants of Fig,5, Fig.8 shows the cross section through a fastening part in the region of the spring attachment before the angling of the side walls, Fig.9 shows a cross section through a fastening part in the region of the spring attachment after the angling of the side walls, and Fig.10 shows a section through a receiving opening of the fastening part. Description of the exemplary embodiments A fastening part 10 of a wiper has a receiving opening 12 or 46 at one end for a wiper shaft 44 (Fig. 10) and forms a part 14 of a hinged joint at the other end (Fig.l). The fastening part 10 also has at this end an integrally formed spring attachment 16 on which a c-shaped clip 18 of a tension spring (not illustrated) engages. The spring attachment 16 is formed from a side wall 24 of the u-shaped cross-sectional profile 20 by deep-drawing (Figs 2 and 9). Relatively large tensile forces 64 and 66 act via the c-shaped clip 18 on the spring attachment 16 from different directions. The cross section of the spring attachment 16 is of appropriately stable design by having a round hollow profile which has the larger cross section in the transitional region, to the side wall 24 and decreases as far as a constriction 34, The constriction 34 forms the engagement region of the c-shaped clip 18 and therefore expediently has a contour 36 which is matched to the cross-sectional contour of the c-shaped clip 18. In addition, the cross section of the spring attachment 16 increases again from the constriction 34 to the free end, with the result that a secure fit of the c- shaped clip 18 is ensured. This is particularly important, especially since the c-shaped clip 18 executes a relative movement with respect to the spring attachment 16 during the swinging down process- In order to reduce the friction between the c-shaped clip 18 and the spring attachment 16, the region of the constriction 34 is expediently coated with a bearing material or is surrounded by a ring of plastic 70. The spring attachment 16 is deep-drawn in a phase in which a flat plate 28 is still present. In the process, first of all a depression 56 is formed, material being drawn in over a large surface (Fig. 3). Subsequently a cylindrical part 58 is formed in a number of steps (Fig. 4) . The said cylindrical part is then compressed in the longitudinal direction 68 in an appropriate die, producing the constriction 34 (Fig. 5) . In one refinement of the invention, the constriction 34 is produced by an opening 60 being punched into the end-side base 38 of the cylindrical part 58, the said opening being widened in a further working step (Figs 6 and 7). After the spring attachment 16 has been formed, the parts of the side walls 22 and 24 are angled relative to the part of the covering wall 2 6 in the arrow direction 3 0 or 32, the u-shaped cross-sectional profile 20 being formed from the flat plate 28 (Figs 8 and 9) . The spring attachment 16 is then situated on the side wall 24 and protrudes with its free end into the u-shaped cross-sectional profile 20. In order to laterally fix the tension spring in place, the constriction 34 is at a distance 42 from the profile centre 40. This distance is produced by an additional calibrating step after the angling. The receiving opening 12 is arranged on the covering wall 26 of the u-shaped cross-sectional profile 20. It has a conical shape which protrudes into the u-shaped cross-sectional profile 2 0 of the fastening part 10 and tapers from the covering wall 26 as far as a collar 62. Fig. 10 shows the fastening region of the fastening part 10, a receiving opening 46 being illustrated as a variant. A wiper shaft 44 has at its free end a cone 54 which fits into the conical receiving opening 46. The fastening part 10 and the wiper shaft 44 are connected fixedly, but detachably, to each other by a screw nut 50 being screwed onto a threaded pin 48. In order to additionally secure the fixed connection, the cone 54 has a fluting and a washer 52 is arranged between the fastening part 10 and the screw nut 50. The receiving opening 12 or 46 is expediently produced by deep-drawing. According to the invention, the spring attachment 16 on the fastening part 10 is likewise deep-drawn and both deep-drawn regions are placed into the flat plate 28 in one phase. WE CLAIM : 1. Fastening part (10) of a wiper, which has a receiving opening (12, 46) at one end for a wiper shaft (44) and forms part (14) of a hinged joint at the other end and is formed from a flat plate (28) by deep-drawing, punching and bending, has a u-shaped cross-sectional profile (20) and a spring attachment (16), characterized in that the spring attachment (16) is formed from a side wall (24) of the u-shaped cross- sectional profile (20) by deep-drawing. 2. Fastening part (10) as claimed in claim 1, wherein the spring attachment (16) decreases in cross section from the side wall (24) as far as a constriction (34) and increases in cross section from the constriction (34) to the free end. 3. Fastening part (10) as claimed in claim 2, wherein the contour (36) of the constriction (34) is matched to the cross-sectional contour of a c-shaped clip (18). 4. Fastening part (10) as claimed in any one of preceding claims, wherein an end-side base (38) of the spring attachment (16) has an opening (60). 5. Fastening part (10) as claimed in any one of preceding claims, wherein the receiving opening (12) extends conically towards a covering wall (26) of the u-shaped cross-sectional profile (20) and has a collar (62) at its end facing into the fastening part (10). 6, Fastening part (10) as claimed in any one of claims 1 to 4, wherein the receiving opening (46) tapers conically towards the covering wall (26). 7. Fastening part (10) as claimed in any one of preceding claims, wherein in the region of bearing (34) of the c-shaped clip (18) the spring attachment (16) is coated with a bearing material or is surrounded by a ring (7) made of plastic. 8. Method for producing a fastening part (10) as claimed in any one of preceding claims, characterized in that first of all the spring attachment (16) is formed in the flat plate (28) and subsequently the parts of the side walls (22, 24) are angled relative to the part of the covering wall (26). 9. Method for producing a fastening part (10) as claimed in any one of preceding claims, wherein the constriction (34) of the spring attachment (16) is produced by compression in the longitudinal direction (68). 10. Method for producing a fastening part (10) as claimed in claim 4, wherein the constriction (34) is produced by widening the opening (60) in the base (38) of the spring attachment (16). 11. Method for producing a fastening part (10) as claimed in any one of the claim 8 to 10, wherein the receiving opening (12, 46) is formed at the same time as the spring attachment (16), and after this working step the side walls (22, 24) are angled. 12. Fastening part of a wiper, substantially as hereinabove described and illustrated with reference to the accompanying drawings. 13, Method for producing a fastening part, substantially as hereinabove described and illustrated with reference to the accompanying drawings.

Documents:

abs-in-pct-2002-494-che.jpg

in-pct-2002-494-che claims duplicate.pdf

in-pct-2002-494-che-abstract.pdf

in-pct-2002-494-che-claims filed.pdf

in-pct-2002-494-che-claims granted.pdf

in-pct-2002-494-che-correspondnece-others.pdf

in-pct-2002-494-che-correspondnece-po.pdf

in-pct-2002-494-che-description(complete)filed.pdf

in-pct-2002-494-che-description(complete)granted.pdf

in-pct-2002-494-che-drawings.pdf

in-pct-2002-494-che-form 1.pdf

in-pct-2002-494-che-form 18.pdf

in-pct-2002-494-che-form 26.pdf

in-pct-2002-494-che-form 3.pdf

in-pct-2002-494-che-form 5.pdf

in-pct-2002-494-che-other documents.pdf

in-pct-2002-494-che-pct.pdf