Sunshade assembly and open roof construction provided therewith

A sunshade assembly for use in a vehicle roof assembly comprises a flexible sunscreen having at least a central part and two opposed inwardly folded longitudinal edges connected to the central part by means of folding lines. A winding shaft for winding and unwinding the flexible sunscreen is provided at the trailing edge and an operating beam at the leading edge of the sunscreen. Two opposed longitudinal guides retain therein and guide corresponding ones of the folded longitudinal edges of the sunscreen. The guides are provided with locking members for engaging an outer end of the inwardly folded longitudinal edges for preventing these edges from moving out of the longitudinal guides when the sunscreen is at least partly unwound. The sunscreen includes at least two members which are each arranged substantially parallel to a respective longitudinal edge and which are buckle-stiff in a direction parallel to said longitudinal edge.

BACKGROUND

Such sunshade assemblies are known in wide number of varieties. The sunscreens are tensioned in lateral direction in order to provide a sleek appearance to the people in the vehicle. The lateral edges of the sunscreen retain the edges of the sunscreen within the guides so that the sunscreen remain stretched. A spring within the winding roller ensures a reliable winding up, i.e. opening of the sunscreen, while the closing of the sunscreen is effected by moving the operating beam, either by hand or by the motorized drive. Due to the increase in size of the sunscreen and the increased sliding forces in the guides, the spring should be made stronger as well. This is a problem as the space within the winding roller is limited. Enlarging the roller would decrease the headroom within the vehicle.

SUMMARY

A sunshade assembly, in particular for use in a vehicle roof assembly, includes a flexible sunscreen having at least a central part, two opposed inwardly folded longitudinal edges connected to the central part by means of folding lines, a leading edge and a trailing edge. A winding shaft is joined the sunscreen at its trailing edge for winding and unwinding the flexible sunscreen, while an operating beam is attached to the leading edge. Two opposed longitudinal guides for retaining therein and guiding corresponding ones of the inwardly folded longitudinal edges of the flexible sunscreen. The guides are provided with locking members for engaging an outer end of the inwardly folded longitudinal edges for preventing these edges from moving out of the longitudinal guides when the sunscreen is at least partly unwound. The flexible sunscreen is provided with at least two members which are each arranged substantially parallel to a respective longitudinal edge of said sunscreen and which are buckle-stiff in a direction parallel to said longitudinal edge. The buckle-stiff members extend at least partly within and preferably are guided by said longitudinal guides along the whole length from the operating beam to the winding shaft in the fully unwound condition of the sunscreen.

Due to the buckle-stiff members, it is possible for the operating beam to push the sunscreen in order to be wound-up. The pushability of the members avoids wrinkling of the sunscreen as the members will remain stable and take the sunscreen along while being taut laterally and longitudinally. As the sunscreen can be pushed by the operating beam, the pulling force of the spring in the winding roller can be reduced so that a small spring in the winding roller might be sufficient. Lower forces will also result in a more constant operating speed.

The spring in the winding roller can even further reduced or even left out if the members are biased towards a spiral shape. Alternatively or additionally, a smaller motor may be used for driving the operating beam which will result in a lower noise level.

In one embodiment, the buckle-stiff members each comprise at least one buckle-stiff wire which may be provided at the inwardly foldable longitudinal edges. For example, the inwardly foldable longitudinal edges each comprise two integrated, substantially parallel wires.

In another embodiment, the buckle-stiff members are strips provided in the central part of the sunscreen.

In one embodiment, the strips are made of metal, in particular steel, which may have a thickness of ca. 002-0.15 mm.

Due to the small thickness of the steel strips, they will not cause problems with winding up the sunscreen. Generally, the strips will have a larger thickness when they are biased to a spiral shape. This will not hinder winding up the sunscreen as the strips will then promote winding due to their tendency to coil to their spiral shape.

In an embodiment, the central part of the sunscreen is made of cloth like material or material having similar properties, the strip may be positioned next to an edge of the cloth-like material and attached to the cloth-like material by means of a connecting member which may cover at least one side of the strip and an adjacent portion of the cloth-like material. The connecting member may be tape or woven or non-woven cloth and may be attached for example glued, welded or stitched to the material of the central part of the sunscreen.

The connecting member, such as the tape, may cover both sides of the strip, the inwardly foldable longitudinal edge and the adjacent portion of the cloth-like material in order to form a integrally bonded unit. A reinforcement, for example in the form of a strip e.g. from plastic, steel or the like, may be provided within the inwardly foldable edge, in particularly within said tape.

Alternatively, each strip is attached on a side of the central part of the sunscreen. This will lead to a more stable structure needing less lateral space, but this will cause an increased roll-up thickness.

In one embodiment, each strip is guided by the respective guide so as to reduce the buckle tendency of the members. Each guide may be shaped such that each strip is able to contact the guide at least at two separated positions, one above and one below the strip. In case each guide is shaped such that each strip is able to contact the guide at three separated positions, two are on one side and one is on the other. Each strip is then carefully guided.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

Firstly referring toFIG. 1, an example is illustrated of an open roof construction for a vehicle, such as a passenger car, having a roof assembly and comprising a sunscreen assembly in accordance with aspects described herein. Said roof assembly is for opening and closing at least one roof opening1in a stationary roof part2of the vehicle and includes at least one movable closure member, in particular a rigid, transparent panel3which, by means not illustrated in detail but known per se, can be moved for opening and closing said roof opening1. Commonly, as is known, the movable panel3is guided in longitudinal guides mounted to or formed in the stationary roof part2along longitudinal sides12of the roof opening1. A user operated device such as a motor or crank (not illustrated) is operably coupled to the panel3via cables or the like to move the panel3selectively between its open and closed positions. InFIG. 1the closure panel3has been illustrated in a position in which it opens the roof opening1.

A sunshade assembly is positioned below the roof opening1. Basically, said sunshade assembly comprises a flexible sunscreen4, a rotatable winding shaft5for winding and unwinding the sunscreen4at a first transversal trailing edge and two opposite longitudinal guides6and7. The panel guides6,7can be connected to or formed integral from a single unitary body with the guides of the closure panel (not illustrated). Likewise, the guides6,7can be separate from the guides of the panel3. Drive members may be provided, which inFIG. 1have been illustrated schematically by dotted lines9,10. As is known per se, the drive members9may comprise flexible longitudinal members, such as a push and pull cable, driven by an actuator11such as an electric motor or hand crank for a reciprocating movement for winding and unwinding the flexible sunscreen4.

Each drive member9,10is connected to an operating beam8provided at a transversal leading edge of the sunscreen4remote from the trailing edge. Although the reciprocating movement of the sunscreen4primarily is generated by the reciprocating movement of the drive members9and10as caused by the actuator11, it is possible too that in addition the winding shaft5is preloaded in a sense for winding the sunscreen4thereon. Further it should be noted that the movement of the sunscreen4also may be initiated manually by engaging the operating beam8.

Now, reference is made toFIG. 2which schematically shows a cross section according to II-II inFIG. 1in which only the flexible sunscreen4and the longitudinal guides6,7have been represented without any details. The flexible sunscreen4has a central part4′ and two opposed inwardly folded longitudinal edges4″ connected to the central part by means of folding lines13. The opposed longitudinal guides6,7for receiving therein and guiding corresponding ones of the inwardly folded longitudinal edges4″ of the flexible sunscreen4are provided with locking members14for engaging an outer end17of the inwardly folded longitudinal edges4″ for preventing these edges from moving out of the longitudinal guides6,7. The locking members14define a groove15in the guides6,7for retaining therein the longitudinal edges4″ to hold the sunscreen taut in the lateral direction. The height of the groove15in the guides6,7in which the longitudinal edges4″ are received is smaller than the width of these edges4″ so that it is not possible for the edges4″ to rotate within their grooves15if the sunscreen central part4′ exerts a force on the edges4″. The rigidity of the edges4″ in lateral direction is sufficient to reduce their bending during normal use of the sunscreen4, so that the edges4″ are retained within their grooves15in a reliable manner. The lateral edges may be made e.g. from stiffened cloth, plastic tape, a strip, for example from plastic or steel, or combinations thereof. At a position near the winding shaft5, the inwardly foldable edge4″ is unfolded to a position in extension of the central part4′ in order to be wound. However, it would be possible as an alternative to further fold the edge4″ until positioned flat against the central part4′.

FIG. 3ashows an embodiment in which the central part4′, made mainly from cloth-like (elastic) material, is completed by a strip18(e.g. steel) positioned next to a longitudinal edge of the cloth-like material and attached to the cloth-like material by means of a plastic tape19which is e.g. glued or welded to the cloth-like material, to the strip18and to itself or to any insert20of the inwardly foldable longitudinal edge4″, as is shown inFIG. 3b.

The strip18extends mainly within the guide6,7so as to be invisible for occupants of the vehicle and so as to be guided by the respective guide6,7to support the strip18to improve the buckle-resistance thereof and keep it in a straight path following the guide6,7. In the embodiment ofFIG. 3a, each guide6,7is shaped such that it provides three separated lines of contact (each indicated with a dot21) to the strip18, two spaced positions21below the strip18and one above, which is positioned between the others, particularly centrally between.

In the embodiment ofFIG. 3b, each guide6,7provides two lines of contact21, one positioned above and one below the strip18at spaced locations. An even better stability of the guidance of the sunscreen4could be obtained if each guide6,7and the strip18is arranged in an upside down position, so thatFIG. 3bwould be mirrored in a vertical direction.

FIG. 4shows another embodiment in which each strip18is positioned on the lower side of the cloth-like material of the central part4′ which is extended into the guides6,7up to or even beyond the folding connection13. The cloth may be attached, e.g. glued, welded or melted to the strip18, while the side of the strip18facing away from the cloth-like material may be covered by a material22having a low coefficient of friction, for example a thin layer of slick cloth or tape the edges of which may be attached to the cloth-like material. The foldable edges4″ may be made from the same cloth-like material as the central part4′ but could be stiffened, for example by impregnation with plastic material, such as polyurethane, that is already present in the cloth-like material, or impregnation with separate plastic material, for example from a thin strip of plastic such as polyester. Such strip could also be maintained as a reinforcement strip attached, e.g. glued, to the edge4″.

The guide6,7in this embodiment is also shaped such as to provide two lines of contact21to the area of the sunscreen4where the strip18is provided. In this embodiment, the inwardly folded longitudinal edge4″ of the sunscreen4is actually folded in downward direction, so that the guide6,7is also “upside down”. The line of contact21below the strip is positioned laterally inwardly of the line of contact21above the strip18. As mentioned, this upside down arrangement offers more stability in case of a guide6,7providing two lines of contact21. However, all embodiments, including that ofFIG. 3acould be used in upside down fashion or not. It is noted that the lines of contact21can have a considerable width.

The strip18, for example spring steel, may be made in a thickness of for example 0.02-0.15 mm. The steel strip may be straight in a relaxed state, or may be spiral-shaped in a relaxed state to assist in winding the sunscreen4. In the latter case, the steel strip will normally have a thickness in the upper region, e.g. around 0.015 mm, while the straight strip may for example be 0.05 mm in thickness. Of course, it is possible to make the strip18from another material (such as but not limited to other metals, plastics and/or other compositions) as long as it has the required properties of stiffness and buckle resistance.

FIG. 5shows an embodiment in which the buckle-stiff member is formed by two parallel wires23, for example, steel wires or thin steel cables, which are provided within the inwardly folded longitudinal edges4″. More or less wires23may be provided. In one embodiment, one is at the extreme end17of the edge4″ and the other at a distance from it. In the embodiment shown, there is also a strip18provided next to the central part4′ of the sunscreen to further improve buckle resistance.

FIG. 6shows the attachment of the sunscreen4to the operating beam8. It is clear that the strip18(e.g steel), the tape and the adjacent longitudinal edge4″ of the sunscreen4are extended beyond the central part4′ of the sunscreen and the steel strip18is fixedly clamped by a clamping member24in a sandwich construction to an end part of the drive member9,10(here a push and pull cable) along a sufficient length so that push forces from the drive member9,10can be reliably guided into the steel strip18. No pilot is required. The beam8is attached to the front of the sunscreen4and/or to the clamping members24. In case the sunscreen is manually adjustable, the strips18will be attached to the beam8to transmit forces from the beam8to the sunscreen4. The attachment of the strip18is effected here by fitting pins and screws, but all kinds of other arrangements are conceivable.

In other embodiments (not illustrated) the following features may be incorporated: when the longitudinal edges4″ comprise a core surrounded by a separate layer of for example tape, the core may have a reduced thickness such that the overall thickness of the edges4″ is substantially the same as the thickness of the central part4′ of the flexible sunscreen4; this may apply too to parts of the central part4′ close to the folding lines13; a separate layer16surrounding the edge4″ and extending over and beyond the folding line13may be provided with openings coinciding with the folding line13; a folding line13may be replaced by a hinge.