Patent Description:
<CIT> discloses a device for opening and closing a door in railway and bus cars. The device has a structure which comprises an rotatable ejection drive assembly and a translation guide. The ejection drive assembly comprises a lower and upper ejection drive arm joined at their base ends at an axis of rotation. At a free end of each ejection drive arm, a clamp carrying a pivoted support with an associated slide bush is provided. The slide bushes are engaged with a lower and upper slide bar which are integral with a door leaf. These engagements form a first and a third backup point for the door. A bracket at a front edge of the door forms a second backup point. The first, second and third backup point provide a robust and heavy structure for carrying the door leaf.

To obtain a sufficient robust device, the structure of the device is sized accordingly. However, a problem of this known device is that it requires too much of a built-in space which is commonly not or hardly available. In designing a passenger vehicle, a vehicle designer determines an environment which is available for a door system supplier in which the sliding door system has to fit. A built-in space at a chassis surrounding the door leaf is often very narrow which requires a challenging slim design of the sliding door system. In practise, this known device with its robust and voluminous spatial components often does not fit.

<CIT> discloses a door system with a door leaf to close off an entrance opening of a bus. For bringing the door leaf from a closed position to an open position, the door system has a displacement system which comprises a movable organ. At a leading edge of the door leaf, this movable organ is fixed to the door leaf via a supporting arm. The movable organ is movable along a rotatable rod mounted to a framework above the door leaf. Via the movable organ, the door leaf is suspended from a first suspension point and a second suspension point.

A wheel is provided at a rod end at the second suspension point to allow a rotational movement of the rod. The rotation of the rod around the first suspension point is determined by a track system which comprises a guiding strip with an curved end. Two running wheels are located at each side of the guiding strip and are connected via V-shaped levers to a turning rod. The running wheels are located playfree at opposite sides of the guiding strip, and the rotation axes are substantially located in line with the rotational axes of the turning rod.

A challenge regarding this known door system is to improve its robustness while being restricted to a narrow build-in space.

Many alternative embodiments of sliding door systems are known. It is desirable to provide a configuration of a sliding door system which is robust and compact at the same time to fit in a narrow built-in space.

Regarding the above-mentioned prior art, it is remarked that any discussion of documents, acts, materials, devices, articles or the like included in the present specification is for the purpose of providing a context for the present invention, and is not to be taken as an admission that any such matters form part of the prior art or were before the priority date of each claim of this application common general knowledge in the field relevant to the present invention.

The general object of the present invention is to at least partially eliminate the above mentioned drawback and/or to provide a usable alternative. More specific, it is an object of the invention to provide a sliding door system having a robust structure, wherein the structure still fits in a narrow built-in space.

According to the invention, this object is achieved by a sliding door system according to claim <NUM>.

The sliding door system comprises a framework and at least one door leaf having a front edge and a rear edge. The door leaf is displaceable in a transversal direction relative to the framework. The door leaf is displaceable by a sliding motion from a closed position to an open position to provide a doorway in the framework. In particular, the sliding door system is a passenger vehicle sliding door system for a public-transport vehicle. The vehicle passenger sliding door system has at least one door leaf displaceable by a sliding motion relative to the framework to provide a doorway for a passenger for entering a vehicle.

The at least one door leaf is suspended from the framework by a support guidance. The support guidance is arranged to guide the at least one door leaf along the framework. Framework means here a fixed surrounding around the door leaf for suspending the door leaf. The framework may be formed at least partially by a vehicle chassis.

The support guidance comprises a swing shaft including at least one swing arm. The swing shaft is swingable about a swing axis. The swing axis is positioned at a side of the doorway. In particular, the swing shaft comprises an upper swing arm positioned at an upper region of the door leaf and a lower swing arm positioned at a lower region of the door leaf. The door leaf is connected to a distal end of the swing arm to enable a plug out motion of the door leaf with respect to the framework.

The support guidance comprises a slide bar. The slide bar extends in the transversal direction of the door leaf. The slide bar is mounted to the door leaf. Preferably, the slide bar has a straight bar body. More preferably, the slide bar is a straight bar which is straight about a total bar length. Advantageously, the slide bar may be manufactured from straight rod material.

The support guidance comprises a sliding carriage. The sliding carriage is slidably mounted to the slide bar. In particular, the sliding carriage is movable along the straight bar body for opening and closing the door leaf by a rectilinear motion along the slide bar. The sliding carriage operates with a rectilinear motion along the straight bar body. The sliding carriage is pivotally connected about a carriage pivot axis to the distal end of the swing arm.

Further, the sliding door system comprises a steer guidance for steering the sliding motion of the door leaf. The steer guidance includes a steering track. The steering track extends in the transversal direction. Preferably, the steering track has a straight track body for opening and closing the door leaf by a rectilinear motion along the steering track. More preferably, the steering track is straight about a total track length. Advantageously, the steering track may be manufactured from straight rod material. The front edge of the door leaf is coupled to the steering track by a front lever. The front lever is mounted to the door leaf nearby the front edge.

According to the invention, an improvement is obtained by providing a fixed mounting of the steering track to the framework. The steering track is immovably mounted to the framework. The steering track has a fixed position. The steering track is arranged separate from movable components which form the support guidance for suspending the door leaf. In comparison with the prior art system, the steering track according to the invention is immovably fixed to the framework and mechanically seen independent and no longer part of the support guidance formed by an operable assembly of the swing shaft with the swing arm coupled with the slide bar by the sliding carriage. This independent mounting of the steering track allows an increase of a rigidity of the suspension of the door leaf formed by the support guidance and at the same time a modification of a configuration of other remaining components of the sliding door system. These remaining components may have a more compact design as a possible reduction in their rigidity can be compensated by an increased rigidity of the movable components forming the support guidance. Herewith, a compactness of a certain part of the structure can be increased which beneficially allows the sliding door system to fit within an available narrow built-in space at certain places of the framework around the door leaf.

This provided design freedom is especially beneficial for a sliding door system supplier who has to supply to a chassis builder in which the chassis design limits a possible configuration of a sliding door system. The compact configuration of the sliding door system according to the invention allows the supplier to comply to the requirements set by a bus car builder.

In addition, the sliding door system according to the invention may provide further advantages. The fixation of the steering track allows for example to obtain a stabile and accurate angular end position of the door leaf when the door leaf is placed in the open position. Especially, in a passenger vehicle, this stabile and accurate angular end positioning of the door leaf is beneficial in preventing an interference with a steered front wheel or nearby chassis components, like a mirror assembly of a bus car.

The fixed steering track may provide an increase in rigidity of the door leaf suspension. In several aspects according to the invention, a robustness and rigidity of the support guidance of the sliding door system may be further increased. Structural features provided by these aspects can be applied in isolation or in combination in an embodiment according to the invention to increase a rigidity of a door leaf suspension by the support guidance. In particular, the sliding door system according to claim <NUM> can be improved by increasing a rigidity of the support guidance by one or more of the features defined in the dependent claims <NUM>-<NUM>. According to some aspects of the invention, structural improvements of the sliding door system can be obtained by improving a rigidity of a connection of the door leaf to the swing shaft.

In a first aspect, an arrangement of the slide bar can be improved to increase a rigidity of the connection of the door leaf of the sliding door system.

In an embodiment of the sliding door system according to the invention, the slide bar is positioned within a plane formed by a door leaf frame. The door leaf may be formed by a window frame including vertical frame profiles at the front and rear edge of the door leaf, in which the slide bar is fixedly mounted in between the vertical frame profiles. The slide bar may be positioned in between a front frame profile and a rear frame profile of the door leaf. By positioning the slide bar in the plane formed by the door leaf frame, a point of gravity of the door leaf may when seen in a vertical plane coincide or be close positioned to the axial axis of the slide bar, such that an introduction of a momentum of the door leaf with respect to the slide bar is minimised. An offset of a point of gravity of the door leaf with respect to the slide bar is minimised. Minimising the momentum allows a less demanding structure of a complementary rotational constraint below the slide bar. Herewith, the robust slide bar forms a main component in determining a rigidity of the structure. Remaining components can then be configured less robust which is beneficial in providing a sliding door system which has to fit in a narrow built-in space.

In an embodiment of the sliding door system according to the invention, the door leaf comprises only a single slide bar for carrying the door leaf. The slide bar may be connected at only its slide bar ends to the door leaf. Preferably, the slide bar has a circular cross-section. This circular cross-section provides a rotational degree of freedom to the door leaf about an axial axis of the slide bar. In particular, the slide bar has a diameter of at least <NUM>.

Preferably, the slide bar is positioned at an upper region of the door leaf. Herewith, a weight of the door leaf is hanging at the slide bar. The rotational degree of freedom of the door leaf about the axial axis of the slide bar is then constrained at a position below the slide bar. Preferably, a rotational constraint is provided at a lower region of the door leaf.

In an embodiment, only a single rotational constraint is provided at a region of the door leaf below the slide bar. The rotational constraint below the slide bar allows the sliding motion of the door leaf, but defines a rotational position of the door leaf about the axial axis of the slide bar. Preferably, the rotational constraint is positioned at the rear edge of the door leaf. The rotational constraint may be formed by a door leaf connection to a distal end of a lower positioned swing arm of the swing shaft. The door leaf connection may e.g. be formed by a U-shaped track mounted to the door leaf and engaged by a track follower, a track wheel, mounted to the lower positioned swing arm. The U-shaped track allows a sliding motion of the door leaf, but constraints a rotational degree of freedom in two rotational directions. Herewith, advantageously, a statical determination of the door leaf in rotation about the axial axis of the slide bar is obtained.

In a second aspect of the invention, the sliding carriage of the support guidance is improved to increase a rigidity of the connection of the door leaf of the sliding door system.

In an embodiment of the sliding door system according to the invention, the sliding carriage has a block-shaped carriage housing. The carriage housing houses a first and second roller pair to engage the slide bar. The carriage housing is oriented in a substantial vertical plane, such that the slide bar is supported by the lower positioned rollers of the sliding carriage. Upper positioned rollers rest on top of the slide bar. The first roller pair is positioned aside the second roller pair. In comparison with a sliding bush, the arrangement of roller pairs contributes to increase a rigidity.

Preferably, the first roller pair is positioned at a distance of at least <NUM>, preferably at least <NUM>, from the second roller pair. Herewith, the sliding carriage is arranged to carry a main portion of a weight and introduced momentum of the door leaf. Advantageously, the robust configuration of the sliding carriage allows to configure other components of the sliding door system more compact, such that the sliding door system may fit better in an available built-in space.

Preferably, the carriage pivot axis is positioned in between the first and second roller pair. The carriage pivot axis extends through the carriage housing in between the first and second roller pair. Herewith, a gravity load of the door leaf is transmitted from the sliding carriage to the swing arm over a relative short distance and off set, such that an introduction of a momentum is reduced.

In a third aspect of the invention, the swing arm of the support guidance is improved. The swing arm has a configuration which contributes to an increase of rigidity of the connection of the door leaf to the door sliding system.

In an embodiment of the sliding door system according to the invention, the swing arm which is pivotally connected to the sliding carriage comprises a first and second swing arm lever. Preferably, the carriage housing is sandwiched in between the first and the second swing arm lever. The first and second swing arm lever together with the carriage housing in between them form a box-structure which increases a rigidity of the swing arm. Preferably, at least one spacer support is positioned in between the first and second swing arm lever to further increase the rigidity of the swing arm. The at least one spacer support may be provided by a bush-shaped or plate-shaped lever member which may e.g. be welded or glued in between the first and second swing arm lever.

Herewith, according to the aspects of the invention, a mechanical chain of connections of the door leaf to the swing shaft can be improved by increasing a rigidity at this position of connection. The connection can be made more robust by adapting at least any of the slide bar, the sliding carriage and the swing arm, such that a substantial support of the door leaf is provided by this mechanical chain of connections. Remaining components of the sliding door system, in particular the front lever and the steering track of the steer guidance, but also components at a lower region of the door leaf can be configured less robust. These components can be configured in a compact manner, such that they require less built-in space in the surroundings of the door leaf. The configuration according to the invention is beneficial in vehicle design in that the main components forming the door leaf suspension is situated close to the swing shaft where there is generally sufficient space available for placement of the robust components. It is remarked that the swing shaft preferably extends along substantially the whole length of the door leaf. The swing shaft may extend from a lower region to an upper region of the door leaf. However, the swing shaft may also be a short swing shaft which is only locally provided at an upper or lower region of the door leaf. The swing shaft may be sandwiched in between the first and second swing arm lever.

In an embodiment of the sliding door system according to the invention, the front edge of the door leaf is connected to the steering track by a horizontally oriented plate shaped front lever body. The front lever body has a front lever base which is mounted to the door leaf. The front lever body extends from the base. The front lever body interconnects the door leaf and the steering track. Preferably, a track follower is connected at a free end of the front lever body. In particular, the track follower is a track wheel.

In an embodiment of the sliding door system according to the invention, the track follower comprises a horizontally oriented track wheel. The track wheel engages with the steering track to steer an angular position of the door leaf about a vertical axis. The steer guidance may be arranged by comprising only the horizontally oriented track wheel in engagement with the steering track, which may provide a lightweight structure requiring a minimum of built-in space. In a further embodiment, the track follower may further comprise a vertically oriented track wheel engaging the steering track. The vertically oriented track wheel may provide an auxiliary support to the door leaf in addition to the main support provided by the connection of the door leaf at the swing shaft.

In an embodiment of the sliding door system according to the invention, the sliding door system may further comprise a plug guidance for generating a plug motion of the door leaf. The plug motion includes a rotation of the door leaf about a vertical axis. The plug guidance serves to unplug the door leaf out of the closed position. In the closed position, the door leaf is aligned with a plane formed by the framework. When unplugging the door leaf, an unplug motion of the door leaf is made in which the door leaf is rotated about a vertical axis to move a rear edge of the door leaf out of the plane formed by the framework.

The plug guidance comprises a plug track and a plug wheel. The plug track is mounted to the door leaf. The plug track extends in a transversal direction of the door leaf in parallel with the slide bar. The swing arm is provided with the plug wheel which is in engagement with the plug track. The plug wheel is connected to a distal end of the swing arm. The plug track is connected to the door leaf. The plug track has an unplug cam profile in alignment with a linear cam profile. The unplug cam profile may form a heading portion of the plug track. Preferably, the plug track has a straight plug track body. More preferably, the plug track is straight about a total plug track length, such that the plug track can be manufactured from straight rod material. During a rotation of the swing shaft, the plug wheel follows the unplug cam profile, such that the door leaf is pressed out of the plane formed by the framework. When moving the door leaf from the open position to the closed position, in the same manner, the assembly of the plug track and plug wheel causes the door leaf to plug back into the framework. An unplug and plug motion is caused by a rotation of the swing shaft. Herewith, the sliding door system is a plug and slide door system. Advantageously, all guidance elements may be linear, i.e. the slide bar, the steering track and the plug track may be manufactured from straight rod material. No curvatures of rod material are necessary.

Thus, a sliding door system is provided comprising a support guidance for suspending a door leaf with respect to a framework. A steering track is fixed to the framework and an engaging front lever is mounted at a front edge of the door leaf. The support guidance is arranged independent from a steer guidance which provides a design freedom in which a rigidity of the support guidance can be increased independent from the steer guidance. The steer guidance can be designed with a compact configuration. A mechanical chain of connections of the door leaf to the swing shaft can be made more robust by adapting at least one of a slide bar, a sliding carriage and a swing arm, such that a substantial support of the door leaf is provided by this mechanical chain of connections.

Further, the invention relates to a vehicle, in particular a transport vehicle, more in particular a mass transit vehicle, like a bus or a railway vehicle comprising a sliding door system according to the invention. The vehicle may comprise a sliding door system including a single-door leaf or a double-door leaf assembly for opening and closing the doorway in the framework.

The invention will be explained in more detail with reference to the appended drawings. The drawings show a practical embodiment according to the invention, which may not be interpreted as limiting the scope of the invention. Specific features may also be considered apart from the shown embodiment and may be taken into account in a broader context as a delimiting feature, not only for the shown embodiment but as a common feature for all embodiments falling within the scope of the appended claims, in which:.

In <FIG>, a sliding door system according to the invention is denoted overall by reference numeral <NUM>. The sliding door system is a mass transit vehicle sliding door system arranged to open or close a doorway for passengers. A mass transit vehicle may be a railway train or a bus car.

Identical reference signs are used in the drawings to indicate identical or functionally similar components. To facilitate comprehension of the description and of the claims the words vertical, horizontal, longitudinal, cross-sectional and a coordinate system X,Y, Z shown in the drawings - with reference to gravity and common placement of the sliding door system in a vehicle - are used in a non-limiting way.

<FIG> and corresponding figures show a coordinate system including a X-, Y-, Z-axis. The Z-axis defines a height or vertical direction. The X- and Y-axis define a XY plane which is a horizontal plane, in which the X-direction defines a vehicle length direction in a longitudinal direction of the vehicle and the Y-direction defines a vehicle width direction of the vehicle. The X- and Z axis define a XZ-plane which is a vertical plane in length direction. The Y- and Z-axis define a YZ-plane which is a vertical plane in width direction.

Commonly, the sliding door system is positioned at a left or right side of a vehicle chassis, such that a door leaf is placed in the vertical XZ-plane of the vehicle. A width of the door leaf is then measured in the length direction of the vehicle. Hence, a transversal direction of the door leaf is considered in the X-direction. A thickness of the door leaf is considered in the Y direction. A height of the door leaf is considered in the Z-direction.

<FIG> shows the sliding door system having a framework <NUM> and a door leaf <NUM>. The door leaf is suspended from the framework <NUM>. The door leaf is movable with respect to the framework <NUM> by a sliding motion from a closed position CP -as shown in <FIG> - to an open position OP as shown in <FIG>. The sliding motion is a movement of the door leaf <NUM> in the transversal direction, the X-direction. A drive system for driving the door leaf is not shown. Here, the sliding motion is combined with a plug motion. A plug/unplug motion is a rotational movement of the door leaf <NUM> about a vertical axis A-A to move the door leaf <NUM> respectively in or out the framework <NUM> in the Y-direction.

The framework to may be an item of the sliding door system itself. Generally, the framework <NUM> is at least partially formed by a chassis of a vehicle. In supplying the sliding door system for installation into the vehicle, an auxiliary framework, a so called cassette system, for holding components may be used to install the sliding door system <NUM> into the chassis of the vehicle.

The door leaf <NUM> has a door window <NUM> which is mounted to a door leaf frame <NUM>, also called a window frame. The door leaf frame comprises a front frame profile <NUM> and a rear frame profile <NUM> which extends in a vertical direction. The front frame profile <NUM> forms a front edge or so called leading edge of the door leaf <NUM>. The rear frame profile <NUM> forms a rear edge or so called trailing edge of the door leaf <NUM>.

The door leaf <NUM> is suspended from the framework <NUM> by a support guidance <NUM>. The support guidance <NUM> comprises several components which are further illustrated in <FIG>.

The support guidance <NUM> comprises a swing shaft <NUM> which is pivotable about a vertical swing axis <NUM>. The swing shaft <NUM> is provided with at least one swing arm <NUM>. Here, an upper swing arm <NUM> is positioned at an upper region of the swing shaft <NUM> and a lower swing arm <NUM> is positioned at a lower region of the swing shaft. Each swing arm <NUM> has a free end which is connected to the door leaf.

The support guidance <NUM> comprises a slide bar <NUM>. The slide bar <NUM> has a slide bar body <NUM> which has a circular cross-section. In particular, the slide bar has an outer diameter of at least <NUM>, in particular at least <NUM>. The slide bar <NUM> extends in a transversal direction and is mounted to the door leaf <NUM>. The slide bar <NUM> has a straight bar body <NUM>. Preferably, the slide bar <NUM> is a straight bar about a total bar length.

Here, at only both ends <NUM>, <NUM>, the slide bar is mounted to the door leaf. The slide bar <NUM> has an unmounted length bridging a distance of at least <NUM> between the front edge and the rear edge of the door leaf <NUM>. The slide bar <NUM> forms part of the door leaf frame. The slide bar <NUM> is positioned in a plane formed by the door leaf frame. A first slide bar end <NUM> is mounted to the front frame profile <NUM> and a second slide bar end <NUM> is mounted to the rear frame profile <NUM>.

The support guidance <NUM> comprises a sliding carriage <NUM>. The sliding carriage is movable along the slide bar <NUM>. The sliding carriage is movable along the straight bar body <NUM>. The sliding carriage operates with a rectilinear motion along the straight bar body <NUM>. The sliding carriage has a carriage housing <NUM> for housing a first roller pair <NUM> and a second roller pair <NUM>. The first roller pair <NUM> is spaced at a distance of at least <NUM>, in particular at least <NUM> from the second roller pair <NUM>. The carriage housing <NUM> is pivotally connected to the upper swing arm <NUM> about a carriage pivot axis <NUM>. The carriage pivot axis <NUM> extends in parallel with the swing axis <NUM>. Here, the carriage pivot axis <NUM> is positioned in between the first and second roller pair <NUM>, <NUM>. The carriage pivot axis <NUM> extends through the carriage housing.

Here, as shown in <FIG>, <FIG>, the carriage housing <NUM> is sandwiched in between a first swing arm lever <NUM> and a second swing arm lever <NUM>. The carriage housing <NUM> together with the swing arm levers <NUM>, <NUM> form a spatial arrangement of the swing arm <NUM> which contributes to its rigidity. At least one spacer support <NUM> is positioned in between the first and second swing arm lever <NUM>, <NUM>. Here, the at least one spacer support <NUM> is bush-shaped. Preferably, the spacer support is welded in between the first and second swing arm lever <NUM>, <NUM>. The interconnection by the spacer support <NUM> further increases a rigidity of the swing arm <NUM>.

Thus, the door leaf <NUM> is suspended to the framework <NUM> by the support guidance <NUM> which is formed by a mechanical chain of connections of the swing shaft <NUM>, the connected sliding carriage <NUM> and slide bar <NUM>. These components <NUM>, <NUM> and <NUM> of the structure have a robust configuration. A weight of the door leaf <NUM> is substantially carried by these components. A structure of other components can be down sized.

As further shown in the top view of <FIG>, to obtain a proper motion of the door leaf <NUM> with respect to the framework <NUM>, the sliding door system further comprises a steer guidance <NUM>. The steer guidance <NUM> includes a steering track <NUM>. In particular, the steering track is a linear steering track. The steering track <NUM> is immovably mounted to the framework <NUM>. The steering track <NUM> is fixed to the framework <NUM>. The door leaf <NUM> is connected with the steering track <NUM> by a front lever <NUM>. The front lever <NUM> is mounted at the front edge <NUM> of the door leaf <NUM> and in engagement with the steering track <NUM> by a track follower <NUM>.

Here, the track follower <NUM> comprises a track wheel <NUM>. The track wheel is oriented in the XY-plane, the horizontal plane. The horizontally oriented track wheel <NUM> is in engagement with the steering track <NUM>, such that an angular position of the door leaf <NUM> about a vertical axis is determined.

The suspension of the door leaf <NUM> may be fully carried out by the sliding carriage <NUM>. Here, an auxiliary track wheel <NUM> is connected with the front lever <NUM> to allow the steering track <NUM> to provide some further support to the door leaf which is especially beneficial in an extreme position of the door leaf, in particular in a position of the door leaf <NUM> nearby the closed position CP. As a load of the door leaf mainly acts at the support guidance situated at the swing shaft, the front lever <NUM> at the front edge <NUM> of the door leaf can have a reduced dimension in height direction.

Here, as shown in <FIG>, the front lever <NUM> has a front lever base <NUM> for mounting the front lever <NUM> to the door leaf <NUM> and a front lever body <NUM> extending away from the front lever base <NUM>. The front lever base <NUM> is formed by an angled profile. The front lever body <NUM> is plate shaped and connected to the front lever base <NUM> body <NUM>. The plate shaped front lever body <NUM> is oriented in the horizontal plane.

As shown in <FIG>, the front lever body <NUM> has a free end. A track wheel <NUM> is positioned at the free end of the front lever body <NUM>. The track wheel <NUM> is rotatable about a vertical axis and hence oriented in the horizontal plane to run along a vertically oriented track. An auxiliary track wheel <NUM> is positioned nearby the track wheel <NUM>. The auxiliary track wheel <NUM> is oriented in the vertical plane (rotatable about a horizontal axis) to engage with a horizontally oriented track which may provide some additional support to the door leaf.

In particular <FIG> and <FIG> show a plug guidance <NUM>. The plug guidance <NUM> is formed by a plug track <NUM> which cooperates with a plug wheel <NUM>. The plug track <NUM> has an elongated plug track body which is provided with a running track. The plug track <NUM> has a running track including a linear cam profile <NUM> and an unplug cam profile <NUM>. The linear cam profile <NUM> extends along the elongated plug track body. The unplug cam profile <NUM> is situated at a heading portion of the plug track body. In the closed position of the door leaf, the plug wheel <NUM> is in engagement with the unplug cam profile <NUM>. In an initial movement of the swing shaft <NUM>, the plug wheel <NUM> runs along the unplug cam profile <NUM> causing the door leaf <NUM> to plug out from the framework <NUM>. Subsequently, when the movement of the swing shaft <NUM> continuous and the door leaf has moved out sufficiently far, a sliding motion of the door leaf <NUM> can be started in which the plug wheel <NUM> runs along the linear cam profile <NUM> until the door leaf <NUM> is in the open position as shown in <FIG>.

<FIG> shows a frontal view of the door leaf <NUM> in the open position seen from an outside. In the open position, the door leaf is carried at one side. The suspension of the door leaf is carried out by the support guidance <NUM> located at the swing shaft. The sliding carriage <NUM> is carrying the door leaf <NUM> by an engagement with the slide bar <NUM> which is part of the door leaf frame. A point of gravity of the door leaf <NUM> is located aside the sliding carriage <NUM>. The first and second roller pair <NUM>, <NUM> compensate for an introduced momentum in the XZ plane about a Y axis. In addition, the first and second roller pair <NUM>, <NUM> which each has a concave running profile also compensate for a rotation about a Z axis.

Numerous variants are possible in addition to the embodiment shown in the figures. For example, in a variant of the illustrated embodiment of the sliding door system, an alternative embodiment of the sliding door system may comprise a second assembly of a connection by a slide bar, sliding carriage and swing arm at a lower region of the door leaf.

Although the present invention has been described in detail, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the scope of the invention as hereinafter claimed. It is intended that all such changes and modifications be encompassed within the scope of the present disclosure and claims.

Further, it is remarked that any feature of the sliding door system according to the invention which is described in the embodiments and/or mentioned in the dependent claims is in itself considered patentable without any dependency to another presented feature. In particular, any measure presented in a dependent claim is also considered patentable without dependency of the independent claim.

Thus, the invention provides a sliding door system comprising a support guidance for suspending a door leaf with respect to a framework, wherein the support guidance is formed by a slide bar, a sliding carriage, and a swing shaft with a swing arm, wherein a steer guidance is provided including a steering track fixed to the framework and an engaging front lever mounted at a front edge of the door leaf.

Claim 1:
Sliding door system (<NUM>), in particular a vehicle sliding door system for transport vehicles, like a van, a railway train or bus car, comprising a framework (<NUM>) and at least one door leaf (<NUM>) having a front edge (<NUM>) and a rear edge (<NUM>) which door leaf is displaceable relative to the framework by a sliding motion in a transversal direction (X) of the door leaf (<NUM>) from a closed position to an open position to provide a doorway in the framework and which door leaf (<NUM>) is suspended from the framework by a support guidance (<NUM>), wherein the support guidance comprises:
- a swing shaft (<NUM>) with a swing arm (<NUM>) which swing shaft is swingable about a swing axis (<NUM>) to enable a plug out motion of the door leaf with respect to the framework;
- a slide bar (<NUM>) which extends in the transversal direction of the door leaf (<NUM>) and which slide bar (<NUM>) is mounted to the door leaf (<NUM>);
- a sliding carriage (<NUM>) slidably mounted to the slide bar (<NUM>) and pivotally about a carriage pivot axis (<NUM>) connected to a distal end of the swing arm (<NUM>);
wherein the sliding door system (<NUM>) further comprises a steer guidance (<NUM>) for guiding the sliding motion of the door leaf in which the steer guidance includes a steering track (<NUM>) extending in the transversal direction and in which the front edge (<NUM>) of the door leaf is coupled to the steering track (<NUM>) by a front lever (<NUM>), characterised in that the steering track (<NUM>) is fixedly mounted to the framework (<NUM>).