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Joint part for a windshield wiperRelated Patent Categories: Brushing, Scrubbing, And General Cleaning, Attachments, Optical-member-attachable Cleaner (e.g., Windshield Wiper), Specific Arm StructureJoint part for a windshield wiper description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20060026787, Joint part for a windshield wiper. Brief Patent Description - Full Patent Description - Patent Application Claims
PRIOR ART [0001] The invention is based on a link element for windshield wipers according to the preamble to claim 1. [0002] Conventional windshield wipers have a wiper arm which is comprised of a driven fastening part, a link element that is connected to it via a hinge joint, and a wiper rod rigidly adjoining the link element. The windshield wiper also has a wiper blade, which is coupled to the wiper rod and is comprised of a support bracket system and a wiper strip secured by it. The hook-shaped end of the wiper rod engages between two side walls of the support bracket system and includes a pivot bolt. The link thus produced guides the wiper blade with the wiper strip across a vehicle window; the link element and the support bracket system make it possible for the wiper strip to adapt to a curvature of the vehicle window. A required pressure of the wiper strip is achieved by means of at least one tension spring which secures the fastening part, along with the link element, to the wiper rod by means of the hinge joint. As a rule, the tension spring is suspended with a hook-shaped end on a lateral pin on the fastening part and is suspended with the other, likewise hook-shaped end on a hanging device on the link element. [0003] The form of the individual components of the wiper arm is influenced by different requirements and stresses. They should be embodied to be as torsionally rigid, flectionally resistant, and narrow in the field of view as possible so that the wiper blade is guided in a vibration-free and controlled fashion across the vehicle window and thereby causes little interference in the field of view. Known windshield wipers therefore have a relatively wide fastening part and a link element formed out of sheet metal, which as a rule, has a U-shaped profile that opens toward the vehicle window. Its favorable resistance moment makes it particularly torsionally rigid and it can contain the tension spring so that the spring is hidden. The link element tapers toward its connecting point with the wiper rod so that it is embodied as narrow in the field of view. [0004] The material stresses in the wiper arm depend on various factors such as driving forces and pressing forces, their engagement points and lever arms, as well as the resistance moment of the wiper arm. Since the optimal shape not only has to be matched to the stress progressions and the deflections, but also has to take other considerations into account, such as sufficient space for the tension spring, the flow resistance in the relative wind, and in particular an impairment to visibility during wiper operation, compromises often must be made. [0005] DE 197 35 301 A1 has disclosed a wiper arm in which sheet metal parts, e.g. the fastening part and in particular, the link element with a wiper rod formed onto it, can be folded together with various numbers of sheet metal layers on top of each other in different regions, until the material thickness required for the respective cross section is achieved. In this connection, the material can be folded over by approx. 180.degree. once or more times or remote surface regions can be placed against one another in one or preferably more steps in order to mutually support one another. Consequently, a relatively thin metal sheet can be used to produce different regions with various material thicknesses that can be adapted to the various loads. According to the prior art, the sheet metal parts are made up of flat metal sheets. They have contour surfaces and folding surfaces. The contour surfaces are used for the basic shaping of the sheet metal part and the folding surfaces are used for fastening regions and for producing various material thicknesses. [0006] The still flat sheet metal part for a link element is cut from a metal sheet by means of a cutting or stamping process. According to this manufacturing process, a number of link elements are disposed next to one another so that a rectangle containing the outer contour of the flat sheet metal part meets the material requirements for a link element. Depending on the embodiment of the sheet metal part, various amounts of waste are generated, because even when fold engineering is used, as a rule the flat sheet metal part tapers from the linking point with the fastening part to the free end of the wiper rod in accordance with the decreasing material stress. [0007] The known wiper arm has a hanging device for a tension spring on the link element. This hanging device is comprised of two opposing extensions of folding surfaces pointing toward the linking end, which have holes at their ends and are bent at right angles into a central plane in the intermediary space between the side walls so that the holes congruently overlap. [0008] DE 693 05 442 T2 has disclosed a one-layer, sheet metal linking lever for a wiper arm. Other variants for hanging elements are proposed, which have additional connecting parts embodied in the form of plates or pegs. The additional connecting parts are welded or riveted to the lateral folding surfaces of the link element, or are folded inward to form shoulders. In this embodiment, although no additional waste is generated, it results in a considerable increase in the overall manufacturing costs of the windshield wiper due to an increased number of components. In addition, it is optically unfavorable because the ends of the insertion peg for the spring do not protrude far enough into the inner space between the side walls of the U-shaped profile and therefore are visible from the outside. ADVANTAGES OF THE INVENTION [0009] According to the invention, a slot lateral to the longitudinal axis is let in from the bottom edge into the innermost sheet metal layers of the side walls of a U-shaped link element produced by means of fold engineering and a pin that serves as a hanging device for the tension spring is inserted into this slot. The pin is inserted into the slot from the bottom edge and as a result of its reach, extends relatively far into the inner space of the U-shaped profile, where it is held between the outer sheet metal layers of the side walls, e.g. by being press-fitted into a recess and/or engaged in it in detent fashion. It is also possible that it is secured in an end position by the tension spring when the slot and the covering wall enclose an angle whose vertex points toward the hinge joint. The tension spring, which is suspended on the pin and whose other end is fastened to a lateral strut on the fastening part, secures the link element and the fastening part by means of a common rotation axis constituted by a pivot bolt on the fastening part. [0010] A wiper rod is formed onto one end of the link element and the linking end for the fastening part is disposed at the other end. The pin for the tension spring is disposed approximately in the center of the link element. The suspended tension spring extends from here toward the linking end and thus advantageously in the lower region of the link element so that it is hidden by the side walls of the U-shaped profile and is not visible from the outside. In addition, the spring is easy to install in the pin hanger, which reduces manufacturing costs. [0011] One embodiment of the invention provides that except for a short side, an elongated piece is respectively cut out from the innermost sheet metal layer of each of the side walls in the longitudinal direction and is perforated at its free end; these pieces are bent inward by approx. 90.degree. and their ends overlap so that the holes coincide. The cut out pieces thus constitute a lateral strut on which the tension spring can be suspended. In this regard, it is advantageous that the lateral strut does not have to be installed and attached as an additional component, but rather, parts of the side walls are used as a hanging device for the tension spring, without reducing the stability of the link element. According to the invention, the cut out pieces of the side walls mutually support one another in the center region by virtue of the fact that they overlap and are consequently reinforced at the force engagement point. In addition to a favorable stability, this embodiment of the invention significantly reduces the manufacturing costs because it completely eliminates the installation work required for a lateral strut. [0012] In a variant of the above-described embodiment of the invention, the overlapping ends of the cut out pieces are angled toward the link. As a result, the hook-shaped end of the tension spring can be suspended rotated by 90.degree. so that a spacing, which is required according to the other variant, situated between the covering wall of the U-shaped profile and the lateral strut for the hook of the spring can be eliminated and the whole spring can be disposed deeper into the free space of the U-shaped link element. [0013] The flat sheet metal part, from which the link element with a wiper rod formed onto it is produced by means of fold engineering, has an outer contour which extends from the linking end to the wiper rod end. In the center region, the height of the covering wall and the height of the side walls decrease toward the wiper rod and the contour of the stamped blank is tapered sharply. According to another embodiment of the invention, hook-shaped parts are formed onto the innermost sheet metal layers in this region and are cut or stamped from a metal sheet at the same time as the outer contour of the flat sheet metal part. After the folding, the innermost sheet metal layers of the flat blank of sheet metal extend parallel to the covering wall of the U-shaped profile and the formed, hook-shaped parts extend parallel to the side surfaces. A double-walled hook produced in this manner protrudes into the free space of the completed the U-shaped profile and its end points toward the wiper rod. [0014] One end of the tension spring is simply fastened to this hook during the assembly of the windshield wiper. As a result, according to this embodiment of the invention, the simplified installation reduces manufacturing costs and, through a better use of the sheet metal material, also reduces the amount of waste generated per link element. In addition, favorable strength properties are achieved that are similar to those achieved in the embodiment that uses a hanging pin since the force engagement point of the tension spring on the hook is situated very close to the connection with the inner sheet metal layer of the link element and therefore, the hook is subjected not to a bending load, but chiefly to a shearing load. Furthermore, the latter embodiment eliminates additional components, which also reduces manufacturing costs. DRAWINGS [0015] Other advantages ensue from the following description of the drawings. Exemplary embodiments of the invention are shown in the drawings. The drawings, the specification, and the claims contain numerous features in combination. The specialist will also suitably consider the features individually and will unite them in other logical combinations. [0016] FIG. 1 shows stamping cut-outs of flat sheet metal parts for link elements arranged on a metal sheet, [0017] FIG. 2 is a bottom view of a link element with a wiper rod formed onto it, [0018] FIG. 3 shows a section along a line III-III in FIG. 2, [0019] FIG. 4 shows an enlarged detail of a hanging device for a tension spring, and [0020] FIGS. 5-7 show variants of FIG. 4. DESCRIPTION OF THE EXEMPLARY EMBODIMENTS Continue reading about Joint part for a windshield wiper... Full patent description for Joint part for a windshield wiper Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Joint part for a windshield wiper patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Joint part for a windshield wiper or other areas of interest. ### Previous Patent Application: Windshield wiper Next Patent Application: Upright vacuum cleaner incorporating releaseable locking mechanism for wand assembly Industry Class: Brushing, scrubbing, and general cleaning ### FreshPatents.com Support Thank you for viewing the Joint part for a windshield wiper patent info. IP-related news and info Results in 0.1678 seconds Other interesting Feshpatents.com categories: Electronics: Semiconductor , Audio , Illumination , Connectors , Crypto , 174 |
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