Land vehicles: bodies and tops – Tops – Roof structure
Reexamination Certificate
1999-05-03
2001-02-20
Pedder, Dennis H. (Department: 3612)
Land vehicles: bodies and tops
Tops
Roof structure
C296S221000
Reexamination Certificate
active
06189963
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a guide crank for the cover of an openable motor vehicle roof with a crank body which is connected to the cover and which comprises at least one slotted opening, wherein the opening forms a guideway or is used as the receiver of a guide body which has the guideway.
2. Description of Related Art
One such guide crank is known, for example, from German patent applications DE 35 29 118 C2 or DE 196 23 945 C1. The guideway of the guide crank is used for movable accommodation of a crank pin of a cover actuation mechanism for swivelling and/or moving the cover in the lengthwise direction of the motor vehicle. The crank body of a generic guide crank must have sufficient stiffness and torsional resistance so that the cover does not tend to vibrate under vertical loads, as are caused among others by wind load. The crank should not plasticly deform even under an overload which occurs, for example, when the cover actuation mechanism is actuated with the cover frozen to a vehicle-mounted frame. In this case guide cranks with very long guideways are especially critical. These guide cranks are used in cover actuation mechanisms in which the crank pin is attached directly to a slide piece of a guide rail which runs in the displacement direction of the cover. However, the crank body of a guide crank with a shorter guideway is also somewhat weakened by the slotted opening. A shorter guideway is typically used when the crank pin is attached to a raising lever which is swivel mounted on the slide piece of the guide rail.
Guide cranks of the aforementioned type are therefore made frequently as a relatively thick sheet metal part which, in addition, can have bends. In particular, above or below the opening, relatively high crosspieces must remain in order to prevent plastic deformation of the guideway under load, and to minimize elastic deformation and the tendency to vibration. This results in the fact that generic guide cranks, having a guide body consisting of a sheet metal part, have considerable weight and require a large installation height. If the crank body of the guide cranks of the above mentioned type is made of plastic, it must be made thicker for reasons of strength thereby taking up even more installation height.
These fundamental disadvantages also afflict cranks with crank bodies made as a composite which, for example, has a layered structure consisting of an inner plastic body and preferably two side metal bodies as shown in German patent application DE-44 05 742 C1.
SUMMARY OF THE INVENTION
The object of the present invention is to devise a crank which is characterized by high strength, but which has smaller material thickness and narrow crosspieces above and below the opening relative to conventional cranks, and which can be produced economically without high production cost.
The object is achieved by providing a guide crank having at least one stiffening element which bridges an opening, at least in one partial area, and which joins the material areas of the crank body to one another on either side of the opening. Thus it is possible to make the crank body thin-walled and with narrow crosspieces on either side of the opening. The stiffening elements reinforce the crank body by reducing the free elastic length of the opening. The stiffening elements can be purposefully located at high load points without increasing the construction height. Reliable operation of the crank is greatly improved even in overloaded operation. The guide crank is suited for use in all types of openable motor vehicle roofs such as sliding roofs, lifting roofs, sliding/lifting roofs or louvered roofs. The cover can be a one-part or multipart cover.
Preferably the stiffening element is made U-shaped and is joined by force-fit and/or form-fit to the crank body. It can be formed by a sheet metal strip which is bent in a U-shape and which is locked and/or riveted to the crank body. The sheet metal strip can extend over almost the entire length of the guideway. The stiffening element can be constructed very simply as a metal body bent in a U-shape with a circular cross section which is caulked or wobbled in the receiving holes of the crank body; the crank body likewise feasibly consisting of metal.
In another embodiment of the invention, the stiffening element can be joined by material-fit to the crank body or can be made as one piece with the body. The one-piece version is especially well suited in a crank body of plastic in which at least one stiffening element is molded on at the same time during the molding process of the body.
In terms of production engineering, the stiffening element can also be made as an essentially U-shaped plastic extrusion coating of the crank body, with great freedom in shaping, and the stiffening element can be optimized in terms of strength and space. If the guideway is not formed by the opening of the crank body itself, but by a plastic guide body which is located in the opening of the crank body, it is a good idea to make the guide body and at least one stiffening element in one piece and mold them jointly onto the crank body.
The stiffening element advantageously prestresses the material areas on either side of the opening in an elastic manner in the direction towards one another so that the walls of the guideway are easily prestressed in the transverse direction. A guide pin, which is movably held, adjoins the walls without play. Preferably, the stiffening elements span an area of the opening of the crank body in which there is a section of the guideway which corresponds to the passage from one closed position of the cover to a ventilation position with the rear edge of the cover raised over the solid roof covering of the motor vehicle. Furthermore, a stiffening element feasibly strengthens the opening in a section of the guideway which corresponds to the ventilation position. This ensures that the guide crank is made especially stiff in the cover positions in which overloaded operation can often occur.
These and further objects, features and advantages of the present invention will become apparent from the following description when taken in connection with the accompanying drawings which, for purposes of illustration only, show several embodiments in accordance with the present invention.
REFERENCES:
patent: 4427085 (1984-01-01), Ochiai et al.
patent: 4725092 (1988-02-01), Reintges et al.
patent: 5066068 (1991-11-01), Suzuki et al.
patent: 5593204 (1997-01-01), Wahl et al.
patent: 3919385 (1990-07-01), None
patent: 2 314 050 (1997-12-01), None
Schwanitz Gunther
Staltmayer Thomas
Wittal Roland
Nixon & Peabody LLP
Pedder Dennis H.
Safran David S.
Webasto Karosseriesysteme GmbH
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