Metal deforming – By application of fluent medium – or energy field – With actuated tool engaging work
Reexamination Certificate
1999-10-13
2001-04-03
Jones, David (Department: 3725)
Metal deforming
By application of fluent medium, or energy field
With actuated tool engaging work
C072S062000, C074S60600R, C015S250300, C015S250130, C296S096170
Reexamination Certificate
active
06209373
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a tubular carrier for at least one wiper bearing and a wiper drive of a wiper device.
Known wiper devices have a window wiper frame and several components mounted on it and including a wiper drive having an electric motor and a transmission, a drive shaft with a drive crank and drive rods, a wiper bearing, and driven shafts with driven cranks. The window wiper operates as a support and serves for mounting the wiper device on a chassis of a vehicle. It has numerous components, so that many manufacturing and mounting steps are needed. In order to reduce the weight of the wiper device, hollow profiles or so called tubular plates are used as supports.
Such tubular carriers are disclosed for example in the German patent document DE 29 20 899 C2, in which the tubular members with corresponding projections are inserted in the hollow profile. The projections are located at least partially on the walls of the support and have at least one recess in which the portions of the support are pressed, to provide a form-locking connection between the support and the tubular members. Wiper bearings are released in the pipe. This approach reduces the number of parts when compared with the screw connection. However, the joining process still requires numerous prefabricated components with many manufacturing steps. This makes more expensive the bearing hold and logistics. Furthermore, the massive projections have a substantial weight despite the recesses.
A method of converting tubular members into work pieces is disclosed in the magazine “Werkstatt and Betrieb”, Carl Hanser Verlag, Munhen, 1995, pages 812-815 and the reprint from the publication “Metallumformtechnik”, Claus Dannert Veriag, 1994, under the title “Prazisions-Werkstucke in Leichtbauweise, hergestilt durch Innenhochdruck-Umformen”. This method is used first of all for vehicle industry and operates with high pressures.
The tubular element to be deformed is placed in a subdivided tool, in which the desired workpiece shape is produced. The tool which is mounted in a press is closed by a vertically operating press plunger. The tubular element ends are closed by the closing tool, through which a pressure medium is supplied to press the tubular walls against the inner tool mold. An axial pressure is applied by the horizontally operating plungers on the tube, which is superimposed with inner pressure. Thereby the material which is required for the deformation is taken not only from the wall thickness of the tubular element, but is also provided by the shortening of the tube. The closing tools are axially hollowed during the deformation.
SUMMARY OF THE INVENTION
Accordingly, it is an object of present invention to provide a tubular carrier of a wiper device and a method of producing the same, which avoids the disadvantages of the prior art.
In keeping with these objects and with others which will become apparent hereinafter, one feature of the present invention resides, briefly stated, in a tubular carrier of a wiper device which is deformed without a material removal, and the tubular members for receiving a wiper bearing are formed on the tubular carrier of one piece with it.
Thereby a substantial component of the tubular carrier is produced in one working step in a one-piece workpiece. For the wiper device, the weight, the number of components, the total number of the cutting and joining locations are reduced, and the material diversity which makes difficult a subsequent recycling process is reduced as well.
For further functions, additional shaped or tubular members can be provided. They are preferably opened, when it is needed. Thereby the tubular carrier is ready for a number of applications. The tubular members which are not needed can be closed and therefore the interior of the tubular carrier is protected from moisture and corrosion. It is also possible to produce the additional tubular members individually and when necessary to connect with the tubular carrier by plugging, clamping, screwing, welding, and so on.
The weight of the tubular carrier is very low, since the tubular members can have substantially the same small wall thickness as the remaining profile. Furthermore, by suitable profile, for example non-round cross-section, polygonal profile etc, the easy mounting, the rigidity and the vibration properties can be improved, and locally (depending on loads) different cross-sections can be utilized. With its profiles having a cross-section different from a circular shape, a form-locking connection can be produced in a peripheral direction in a simple manner.
In accordance with an embodiment of the invention, mounting elements can be formed on the ends of the tubular carrier. They can be flat or U-shaped and they can have an opening in form of a hole, elongated hole, or slot. The mounting elements are preferably deformed by pressing from an end portion of the tube and the openings are punched out after this. The above mentioned advantages can be therefore obtained to great extent.
With long tubular carriers and heavy mounting elements, it can be advantageous to provide an additional supporting and mounting element between the ends of the tubular plate. It can engage directly on the tubular carrier by screwing or welding or plugging or clamping in a corresponding receiving seat. The receiving seat can be arranged in a tubular member. Furthermore, the additional supporting and mounting element can be supported indirectly on the tubular carrier by its connection in a similar manner with a projecting housing part of the wiper device.
The inventive tubular carrier can be used for heavy mounting conditions. In correspondence with the spacial peculiarities, it can be curved in one or several planes once or many times.
The inner high pressure process is suitable in advantageous manner for manufacture of the tubular carrier. In this process a subdivided tool mold receives a tubular element and is closed. Sealing tools close the tube ends and are preferably displaced axially, while simultaneously an axial pressure is applied on the tube end. Therefore uniform wall thickness and precise contours are obtained, which need no or only little mechanical post-working. The method allows a flexible shaping, so that the inventive tubular carrier can be easily produced in a complex version with many curvatures in several planes.
A zinc-plated steel tube with a low strength or a tube of an aluminum alloy are especially suitable for the process. They are sufficiently flowable and corrosion-resistant and do not require post-treatment. The aluminum alloys have further weight advantages. A seamless as well as longitudinally welded tube can be utilized.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
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patent: 1998760 (1935-04-01), Hueber
patent: 5074613 (1991-12-01), Unterborn et al.
patent: 5142941 (1992-09-01), Amann et al.
patent: 5222706 (1993-06-01), Hoshino
patent: 5396681 (1995-03-01), Hara
patent: 5441227 (1995-08-01), Hayashi
patent: 5647086 (1997-07-01), Gold
patent: 5862968 (1999-01-01), Traise
patent: 5878631 (1999-03-01), Muehlpforte et al.
patent: 2920899C2 (1981-01-01), None
Hans Pischel, Wiesloch/Bewaehrtes Innenhochdruck . . . / pp. 812-814, 1995.*
Ebbinghaus, A./Praezisions-Werkstuecke . . . / Metallumform-Technik, 1990.
Becker Henk
Boos Tino
Fleischer Claus
Muehlpforte Kurt
Jones David
Robert & Bosch GmbH
Striker Michael J.
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